RELATED APPLICATIONS
This application claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional Application Nos. 62/670,705, filed May 11, 2018, and 62/671,356, filed May 14, 2018, the entire contents of each of which is incorporated herein by reference in their entireties.
STATEMENT AS TO FEDERALLY SPONSORED RESEARCH
This invention was made with government support under P20 GM104937, P30 GM122732 awarded by the National Institutes of Health. The Government has certain rights in the invention.
INCORPORATION BY REFERENCE OF SEQUENCE LISTING
The contents of the sequence listing text file named “21486-641001WO_Sequence_Listing_ST25.txt”, which was created on May 10, 2019 and is 131,072 bytes in size, is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to orthopedic disorders.
BACKGROUND
Arthritis affects tens of millions of patients in the U.S. annually. By 2040, an estimated 78 million (26%) of U.S. adults aged 18 years or older are projected to have physician-diagnosed arthritis. Osteoarthritis (OA) is the most common form of arthritis.
With knee OA, total or half knee replacement is a typical outcome, particularly in elderly subjects. Not infrequently, some patients have to go through secondary repair. Intra-medullar infection, lethal fat embolism, surgery related fracture, unpredictable prognosis and endless post-operative physical therapy are risks shared by the patients. Moreover, patients usually have to double those aforementioned sufferings on the contralateral knee, and even for both hips.
Degenerative disorders such as osteoarthritis, osteoporosis, neurodegeneration, and tumorigenesis are often associated with aging and injury, which induce pro-inflammatory cytokines and matrix proteinases and result in tissue degeneration. For example, OA is a complicated chronic and highly prevalent degenerative joint disease. As the most common musculoskeletal disorder, OA is characterized by the degradation of articular cartilage and joint inflammation. Large numbers of individuals with OA throughout the world suffer from pain most in knees and hips joints. Current treatments are restricted to behavioral interventions and ultimately joint replacement surgery. There are still no effective pharmacological methods for prevention and treatment of OA.
SUMMARY OF THE INVENTION
The invention provides a solution to the long standing problem of treating osteoarthritic conditions in aging joints, e.g., greater than 50 year old, as well as trauma-induced joint OA, e.g., subsequent to an injury such as ligament tear/breach or cartilage, e.g., meniscus damage in an articulating joint.
Accordingly, a method for treating an articulating joint disorder comprises systemically administering to a subject a nucleoside reverse transcriptase inhibitor (NRTI). For example, the subject, e.g., a human subject, is diagnosed as comprising osteoarthritis (OA). In some embodiments, the subject does not comprises an human immunodeficiency virus (HIV, e.g., HIV-1 or HIV-2) infection. Exemplary compounds for treatment include NRTIs such as 3TC (lamivudine), FTC (Emtriva,) ABC (abacavir), TDF (tenofovir), ZDV (azidothmidine), or DDl (Didanosine). Animal subjects such as companion animals, e.g., dogs, cats, as well as performance animals, e.g., horses, are within the scope of the inventions. Joint disorders include age-related and trauma-related OA.
As described above, it is therefore an object of the present invention to provide compounds and pharmaceutical compositions that exhibit anti-inflammation, and in particular, anti-chronic inflammation and/or anti-cartilage degeneration disease activity, as well as pharmaceutical compositions for the treatment of cartilage degeneration diseases, including all kinds of arthritis and skeletal disorders and for the treatment of cartilage degeneration diseases.
Any one or more of these and/or other objects of the invention may be readily gleaned from a review of the description of the invention which follows. Each embodiment disclosed herein is contemplated as being applicable to each of the other disclosed embodiments. Thus, all combinations of the various elements described herein are within the scope of the invention.
Despite the demographics and prevalence of osteoarthritic disease, there are still few or no effective pharmacological methods for prevention and treatment of tissue degenerative orders such OA. NRTIs are currently used for treatment of viral diseases (HIV etc.), the data described herein indicates that these NRTIs are effective for treatment of OA. The compositions and methods described herein do not require surgery or invasive means for therapy, e.g., the methods exclude surgery and/or are used in concert with a surgical intervention. Advantages of the invention include avoidance of an invasive procedure such as surgery as well an ease of use, low cost, and high patient compliance. Furthermore, the method causes neither tissue damage nor pain, and requires less patient supervision and decreased cost of care.
In aspects, provided herein are methods for treating an aging-associated joint disorder, comprising systemically administering to a subject a nucleoside nucleoside reverse transcriptase inhibitor (NRTI). In embodiments, the subject is at least 30, 40, 50, 60, 70, 80 years old or older. In other embodiments, the subject has been diagnosed with an aging-associated joint disorder (e.g., osteoarthritis (OA)). Post-traumatic OA can occur in individuals of any age. In embodiments, the method for treating an aging-associated joint disorder (OA), includes administering an NRTI, e.g., 3TC, FTC, ABC, TDF, ZDV, or DDl.
In other examples, the joint disorder originates or is associated with a trauma (post-traumatic OA), e.g., an injury to the joint or a surgery to a joint. In some embodiments, the subject does not comprise rheumatoid arthritis, an auto-immune disorder. In other embodiments, the subject comprises the auto immune disorder, rheumatoid arthritis.
In embodiments, the NRTI for treating an articulating joint disorder or an aging-associated joint disorder, inhibits the expression of osteoarthritis markers. In embodiments, the osteoarthritis markers comprise collagen type X alpha 1 chain (COL10A1), A Disintegrin and Metalloproteinase with Thrombospondin Motifs 5 (ADAMTS5), matrix metallloeptidase 13 (MMP13), senescence-associated secretory phenotype interleukin-6 (SASP IL-6), Indian hedgehog (Ihh) or interferon type 1 (IFN).
In other embodiments, the NRTI or treating an articulating joint disorder or an aging-associated joint disorder promotes the expression of anabolic markers, wherein the anabolic markers comprise aggrecan (ACAN) and Collagen, type II, alpha 1 (COL2A1).
In aspects, also provided herein are methods for treating a post-traumatic osteoarthritis (PTOA) injury in a subject, comprising systemically administering a nucleoside reverse transcriptase inhibitor (NRTI). In embodiments the subject is diagnosed as comprising osteoarthritis. In other embodiments, the NRTI comprises 3TC, FTC, ABC, TDF, ZDV, or DDl. In embodiments, the method further comprises administering 3MC.
In embodiments, the PTOA results from a high-speed impact twist, or pressure-induced trauma to the articular surface, intraarticular fractures, or joint-destabilizing soft-tissue tears. In embodiments, the PTOA injury is in a joint. In some examples, the joint includes an ankle, knee, or hip.
In embodiments, the methods for treating an articulating joint disorder, for treating an aging-associated joint disorder, or for treating a post-traumatic osteoarthritis injury, comprise administering an NRTI. In embodiments, the NRTI comprises a nucleoside analogue. In other embodiments, the NRTI comprises an adenosine analogue. In embodiments, the NRTI comprises a cytidine analog.
NTRIs include nucleoside analogues. Nucleosides are glycosylamines that can be characterized as nucleotides without a phosphate group. A nucleoside consists of a nucleobase (also termed a nitrogenous base) and a five-carbon sugar (either ribose or deoxyribose), whereas a nucleotide is composed of a nucleobase, a five-carbon sugar, and one or more phosphate groups. In a nucleoside, the anomeric carbon is linked through a glycosidic bond to the N9 of a purine or the N1 of a pyrimidine. Examples of nucleosides include cytidine, uridine, adenosine, guanosine, thymidine and inosine.
Other features and advantages of the invention will be apparent from the following description of the preferred embodiments thereof, and from the claims. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below.
DETAILED DESCRIPTION
Treatment of joint degenerative disorders, as described herein, modulating retrotransposon(s) and/or its regulators and effectors, and their structural analogues are useful to achieve the purpose of inhibiting tissue degeneration and promoting regeneration of joint tissues. The data shown herein, demonstrate the use and efficacy of treatment of degenerative diseases by inhibiting microrna up-regulation of retrotransposon line-1 and use of NTRIs to treat OA and suppress Line-1 activities and prevent primary OA. Line is an acronym for (Long Interspersed Nuclear Element.)
Mechanical stress plays a pivotal role in osteoarthritis (OA) pathogenesis. In some cases, miR-365 expression is stimulated by mechanical loading in chondrocytes and is increased during OA pathogenesis. Moreover, transgenic mice in which miR-365 is specifically over-expressed in Col2a1 lineage cells develop early onset of OA. miR-365 over-expression is sufficient to elevate Line-1 expression in cartilage in vitro and in vivo, the resultant Line-1 expression increase is attributed to the suppression of its inhibitors including Dicer, Prkdc and Sqstm1, direct targets of miR-365. Furthermore, inhibiting Line-1 using NRTIs such as 3TC and FTC, as well as ABC, TDF, ZDV, or DDl rescue primary and secondary OA models in mice. Collectively the data indicate that NRTIs are useful for treatment of OA.
Compositions and methods were developed for inhibiting tissue degeneration and associated inflammation and matrix enzyme secretion by modulating retrotransposon and its regulatory pathways.
OA Pathogenesis
Mechanical stress and inflammation plays a pivotal role in OA pathogenesis. In contrast to rheumatoid arthritis, OA is not an autoimmune disease. The major components of osteoarthritis are not immune cells (contrary to rheumatoid arthritis, which is an autoimmune disease), and OA is associated with wear and tear. miR-365 expression is stimulated by mechanical loading and inflammation in chondrocytes and is increased during OA pathogenesis. Transgenic mice in which miR-365 is specifically over-expressed in Col2a1 lineage cells develop early onset of OA. Retrotransposon activation has been implicated in some aging-associated and chronic diseases, but its role in degenerative joint disease such as OA pathogenesis was not known prior to the invention.
Osteoarthritis occurs as a result of cumulative stress to a joint as a result of aging or as an aftermath of trauma such as an injury or surgical procedure performed on a joint, i.e., in some cases the development of OA is not age-related, e.g., occurs in subjects younger than 45 years old. Effectiveness of NRTIs on improvement of the clinical symptoms, e.g., pain or decreased mobility was a surprising observation in the treatment of age-related or trauma-related OA.
Disclosed herein is a data showing that the levels of retrotransposon Line-1 are significantly higher in the human OA cartilage lesions compared to normal cartilage. MiR-365 over-expression is sufficient to elevate retrotransposon Line-1 expression in cartilage in vitro and in vivo, the resultant Line-1 expression increase is attributed from the suppression of its inhibitors including Dicer, Prkdc and Sqstm1, which are direct targets of miR-365. Furthermore, inhibiting Line-1 using nucleoside reverse transcriptase inhibitors (NRTIs) including 3TC and FTC inhibits aging and trauma induced in art-recognized OA models in mice. OA cells secrete exosomes (vesicles), and Line-1 is present in those exosomes. Such Line-1 containing exosomes can infect non-OA cells.
Collectively the data indicate that OA is alleviated, e.g., effectively treated, by manipulating retrotransposon content and its related regulatory pathways in the cell. Therapeutic compositions include 1) inhibitors of miR-365, 2) Dicer, Prkdc, Sqstm1, or their agonists, 3) inhibiting the antagonists of Dicer, Prkdc, Sqstm1 and their respective pathways, 4) inhibitors or antagonists of retrotransposon including siRNA and NRTI small molecules. For example, NRTIs, which have been and are currently used for inhibiting viruses, can be re-purposed and used as a therapeutic medication to treat joint disease such as OA.
In addition, structural homologs or modified (e.g. methylated) NRTIs may also be used for OA treatment, even if they do not possess inhibitory properties against reverse transcriptase.
Osteoarthritis Markers
Exemplary osteoarthritis markers comprise collagen type X alpha 1 chain (COL10A1), A Disintegrin and Metalloproteinase with Thrombospondin Motifs 5 (ADAMTS5), matrix metallloeptidase 13 (MMP13), senescence-associated secretory phenotype interleukin-6 (SASP IL-6), Indian hedgehog (Ihh) or interferon type 1 (IFN).
Human Collagen type X alpha 1 chain (COL10A1) amino acid sequence is publicly available and can be found under GenBank Accession Number: NP_000484.2; SEQ ID NO: (99); GenBank Accession, incorporated herein by reference.
Exemplary landmark residues, domains, and fragments of COL10A1 include, but are not limited to residues 1-18 (signal sequence), residues 19-680 (mature protein), residues 57-519 (non-helical region), residues 155-202 (collagen triple helix repeat), or residues 520-980 (non-helical region). A fragment of a COL10A1 protein is less than the length of the full length protein, e.g., a fragment is at least 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 100, 200 or more residues in length, but less than e.g., COL10A1 residues in the case of COL10A1 above.
Human COL10A1 nucleic acid sequence is depicted below with start and stop codons underlined. The sequence is publicly available and can be found under GenBank Accession Number: NM_000493.4; SEQ ID NO: (100); GenBank Accession, incorporated herein by reference.
Human A Disintegrin and Metalloproteinase with Thrombospondin Motifs 5 (ADAMTS5) amino acid sequence is publicly available and can be found under GenBank Accession Number: NP_008969.2; SEQ ID NO: (101); GenBank Accession, incorporated herein by reference.
Exemplary landmark residues, domains, and fragments of ADAMTS5 include, but are not limited to residues 1-18 (signal sequence), residues 67-168 (reprolysin family propeptide), residues 207-214 (cysteine switch), or residues 570-622 (thrombospondin type 1 repeats). A fragment of a ADAMTS5 protein is less than the length of the full length protein, e.g., a fragment is at least 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 100, 200 or more residues in length, but less than e.g., ADAMTS5 residues in the case of ADAMTS5 above.
Human ADAMTS5 nucleic acid sequence is depicted below with start and stop codons underlined. The sequence is publicly available and can be found under GenBank Accession Number: NM_007038.5; SEQ ID NO: (102); GenBank Accession, incorporated herein by reference.
Human matrix metalloeptidase 13 (MMP13) amino acid sequence is publicly available and can be found under GenBank Accession Number: NP_002418.1; SEQ ID NO: (103); GenBank Accession, incorporated herein by reference.
Exemplary landmark residues, domains, and fragments of MMP13 include, but are not limited to residues 1-19 (signal sequence), residues 32-91 (Putative peptidoglycan binding domain), or residues 112-267 (peptidase m10). A fragment of a MMP13 protein is less than the length of the full length protein, e.g., a fragment is at least 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 100, 200 or more residues in length, but less than e.g., MMP13 residues in the case of MMP13 above.
Human MMP13 nucleic acid sequence is depicted below with start and stop codons underlined. The sequence is publicly available and can be found under GenBank Accession Number: NM_002427.4; SEQ ID NO: (104); GenBank Accession, incorporated herein by reference.
Human senescence-associated secretory phenotype interleukin-6 (SASP IL-6) amino acid sequence is publicly available and can be found under GenBank Accession Number: NP_000591.1; SEQ ID NO: (105); GenBank Accession, incorporated herein by reference.
Exemplary landmark residues, domains, and fragments of SASP IL-6 include, but are not limited to residues 30-212 (interleukin 6) or residue 73 (glycosylation). A fragment of a SASP IL-6 protein is less than the length of the full length protein, e.g., a fragment is at least 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 100, 200 or more residues in length, but less than e.g., SASP IL-6 residues in the case of SASP IL-6 above.
Human SASP IL-6 nucleic acid sequence is depicted below with start and stop codons underlined. The sequence is publicly available and can be found under GenBank Accession Number: NM_000600.5; SEQ ID NO: (106); GenBank Accession, incorporated herein by reference.
Human Indian hedgehog (Ihh) amino acid sequence is publicly available and can be found under GenBank Accession Number: NP_002172.2; SEQ ID NO: (107); GenBank Accession, incorporated herein by reference.
Exemplary landmark residues, domains, and fragments of Ihh include, but are not limited to residues 1-27 (signal peptide), residues 28-441 (mature peptide), residues 28-202 (IHH N-product), residues 44-189 (hedgehog amino terminal signaling domain) or residues 203-411 (IHH protein C-product). A fragment of a Ihh protein is less than the length of the full length protein, e.g., a fragment is at least 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 100, 200 or more residues in length, but less than e.g., Ihh residues in the case of Ihh above.
Human Ihh nucleic acid sequence is depicted below with start and stop codons underlined. The sequence is publicly available and can be found under GenBank Accession Number: NM_002181.4; SEQ ID NO: (108); GenBank Accession, incorporated herein by reference.
Human interferon type 1 (IFN) amino acid sequence is publicly available and can be found under GenBank Accession Number: NP_000407.1; SEQ ID NO: (109); GenBank Accession, incorporated herein by reference.
Exemplary landmark residues, domains, and fragments of IFN include, but are not limited to residues 1-77 (signal peptide), residues 18-489 (mature peptide), or residues 161-317 (Interferon gamma receptor (IFNGR1)). A fragment of a IFN protein is less than the length of the full length protein, e.g., a fragment is at least 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 100, 200 or more residues in length, but less than e.g., IFN residues in the case of IFN above.
Human IFN nucleic acid sequence is depicted below with start and stop codons underlined. The sequence is publicly available and can be found under GenBank Accession Number: NM_000416.2; SEQ ID NO: (110); GenBank Accession, incorporated herein by reference.
Anabolic Markers
Exemplary osteoarthritis markers comprise aggrecan (ACAN) and Collagen, type II, alpha 1 (COL2A1).
Human aggrecan (ACAN) amino acid sequence is publicly available and can be found under GenBank Accession Number: NP_001126.3; SEQ ID NO: (111); GenBank Accession, incorporated herein by reference.
Exemplary landmark residues, domains, and fragments of ACAN include, but are not limited to residues 1-16 (signal sequence), residues 20-2431 (mature protein), residues 43-154 (IG Aggrecan), residues 153-247 (link domain), or residues 579-674 (link domain CSPGs). A fragment of a ACAN protein is less than the length of the full length protein, e.g., a fragment is at least 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 100, 200 or more residues in length, but less than e.g., ACAN residues in the case of ACAN above.
Human ACAN nucleic acid sequence is depicted below with start and stop codons underlined. The sequence is publicly available and can be found under GenBank Accession Number: NM_001135.3; SEQ ID NO: (112); GenBank Accession, incorporated herein by reference.
Human Collagen, type II, alpha 1 (COL2A1) amino acid sequence is publicly available and can be found under GenBank Accession Number: NP_001835.3; SEQ ID NO: (113); GenBank Accession, incorporated herein by reference.
Exemplary landmark residues, domains, and fragments of COL2A1 include, but are not limited to residues 1-25 (signal sequence), residues 26-1487 (mature protein), residues 201-1214 (triple helical region), or residue 1388 (glycosylation). A fragment of a COL2A1 protein is less than the length of the full length protein, e.g., a fragment is at least 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 100, 200 or more residues in length, but less than e.g., COL2A1 residues in the case of COL2A1 above.
Human COL2A1 nucleic acid sequence is depicted below with start and stop codons underlined. The sequence is publicly available and can be found under GenBank Accession Number: NM_001844.5; SEQ ID NO: (114); GenBank Accession, incorporated herein by reference.
NTRIs for Treatment of OA
Nucleoside Analog Reverse-Transcriptase Inhibitors
Nucleoside analog reverse-transcriptase inhibitors (NARTIs or NRTIs) are a class of antiretroviral drugs. To be incorporated into the viral DNA, NRTIs must be activated in the cell by the addition of three phosphate groups to their deoxyribose moiety, to form NRTI triphosphates. This phosphorylation step is carried out by cellular kinase enzymes. Exemplary NRTIs are listed below:
Zidovudine, also called AZT, ZDV, and azidothymidine, has the trade name Retrovir.
Zidovudine was the first antiretroviral drug approved by the FDA for the treatment of HIV.
Didanosine, also called ddl, with the trade names Videx and Videx EC, was the second FDA-approved antiretroviral drug. It is an analog of adenosine.
Zalcitabine, also called ddC and dideoxycytidine, has the trade name Hivid.
Stavudine, also called d4T, has trade names Zerit and Zerit XR.
Lamivudine, also called 3TC, has the trade name Zeffix and Epivir. It is approved for the treatment of both HIV and hepatitis B.
Abacavir, also called ABC, has the trade name Ziagen, is an analog of guanosine.
Emtricitabine, also called FTC, has the trade name Emtriva (formerly Coviracil). Structurally similar to lamivudine, it is approved for the treatment of HIV and undergoing clinical trials for hepatitis B.
Entecavir, also called ETV, is a guanosine analog used for hepatitis B under the trade name Baraclude. It is not approved for HIV treatment.
Truvada, made of emtricitabine and tenofovir disoproxil fumarate, is used to treat and prevent HIV. It is approved for HIV prevention in the US and manufactured by Gilead.
Another exemplary NRTI includes Tenofovir also known as TDF is a prodrug with the active compound deactivated by a molecular side chain that dissolves in the human body allowing a low dose of tenofovir to reach the site of desired activity.
NRTIs for Treatment of Strict OA
In one example NRTIs can be used for the treatment of strict osteoarthritis (“category one” or “class one”). An exemplary NRTIs include, 3TC, a cytidine analog depicted below. 3TC is commonly referred to as lamivudine, and can be formulated in tablet form (Epivir or Zeffix).
In another example, the treatment for osteoarthritis can include administration with FTC, a cytidine analog depicted below. FTC is also referred to as emtricitabine, 2′,3′-dideoxy-5-fluoro-3′-thiacytidine, Emtriva or Coviracil. FTC can also be administered with tenofovir disoproxil (sold under trade name Viread).
In another example, the treatment for osteoarthritis can include administration of ABC, a guanosine analog. ABC is also referred to as abacavir, or the trade name Ziagen. The structure of ABC is provided below:
Summary data of NRTI on OA is shown in
NRTIs for Treatment of Strict OA and Expanded OA
In another example, NRTIs can be used for the treatment of strict OA and expanded OA, e.g., partially inhibiting expanded OA (“category 2” or “class 2”). An exemplary NRTI includes, ZDV (a thymidine analog). In examples, ZDV is administered to female patients. ZDV is also commonly referred to as azidothmidine, AZT, Retrovir or Zidovudine. The structure of ZDV is provided below:
In another example, the treatment of strict OA and expanded OA comprises administering TDF (an adenosine analogue). TDF is also referred to as tenofovir, 9-(2-Phosphonyl-methoxypropyly)adenine (PMPA), Viread (Gilead Sciences). The structures of TDF, and Tenofovir dispoproxil are shown below. TDF can also be administered with FTC, which is also referred to as emtricitabine, 2′,3′-dideoxy-5-fluoro-3′-thiacytidine, Emtriva or Coviracil.
Summary data of NRTI on OA is shown in
NRTIs for Treatment of Strict OA and Expanded OA.
In other examples, both strict OA and expanded OA are treated by administration of Didanosine, an adenosine analog (commonly referred to as DDl, ddl, Videx, Videx EC, 2′,3′-dideoxyinosine) (“category 3” or “class 3”). No toxicity in a group of less than 40 years old was observed. The structure of didanosine is provided below:
In other examples, both strict OA and expanded OA are treated by administration of Stavudine, a thymidine analog (commonly referred to as d4T, Zerit, Zerit XR, 2′,3′-didehydro-2′,3′-dideoxythymidine). Stavudine was the highest extent of inhibition. The structure of Stavudine is shown below:
Summary data of NRTI on OA is shown in
Osteoarthritis (OA)
Osteoarthritis is a form of arthritis that features the breakdown and eventual loss of the cartilage in one or more joints. OAs can affect the hands, feet, ankle, spine, and large weight-hearing joints, such as the hips and knees.
OA that develops secondary to a wide variety of joint injury is often grouped into a sub-category of OA called post-traumatic osteoarthritis (PTOA). Common injuries that can lead to PTOA include, but are not limited to, high-speed impact trauma to the articular surface, intraarticular fractures, and joint-destabilizing soft-tissue tears. Although the end-stage pathophysiology of PTOA may be similar, there is evidence to suggest that the early biological and mechanical events that initiate and perpetuate disease are distinct between different joints, injury types, and patient populations. The ankle, knee, and hip are the most commonly injured joints in PTOA.
The most common injury precipitating end-stage ankle OA is a severe ankle sprain, when rapid ankle inversion causes the distal tibia to impact the medial aspect of the talar dome, often resulting in an osteochondral lesion. Ligamentous injuries commonly accompany severe ankle sprains and may result in joint instability. The magnitude of the initial cartilage trauma is an important factor in development of ankle PTOA.
There is evidence implicating trauma with the likelihood of developing joint degeneration and OA. PTOA is a degenerative joint disease secondary to injury that may lead to OA years later. It is particularly prevalent in young and active individuals such as those involved in sport during which there is increased risk of sustaining such injury. It can therefore be defined as the presence of a normal joint prior to injury, structural damage at the time of injury and the joint not being compromised by systemic disease. Joint trauma affects all joint tissues leading to physiological, biomechanical and biochemical changes that may progress toward joint degeneration and subsequent development of OA.
Treatment generally involves a combination of exercise, lifestyle modification, and analgesics. If pain becomes debilitating, joint replacement surgery may be necessary to improve the quality of life. Surgical intervention is sometimes recommended after joint injury to correct abnormal joint biomechanics, reducing the risk of secondary injuries, and ideally reducing the risk of OA. Unfortunately, surgical interventions (e.g. AU (gold) reconstruction, meniscectomy, meniscal replacement) do not restore normal joint biomechanics or prevent knee OA. Therefore, it is important to understand which of these patients will develop early-onset knee OA and if this onset of knee OA can be prevented or delayed. Whilst pain management and surgery are current options, currently there are no approved therapies to address post-traumatic arthritis and its prevention.
Stages of OA
Stage 1: Minor
Small lumps of bone called osteophytes may grow in the knee area. There may be slight damage to the cartilage. There will be no apparent narrowing of the space between the bones to indicate that the cartilage is breaking down. People with stage 1 OA are unlikely to feel pain or experience discomfort. The joint will appear normal on an X-ray.
Stage 2: Mild
During this stage, a person may start to notice symptoms, and doctors can see some signs of wear. X-rays and other scans of the knee joints will clearly show more osteophyte growth, and the cartilage will begin to thin. The space between the bones will still appear normal, but the area where the bones and the tissues meet will start to harden. When the tissues harden, this makes the bone thicker and denser. A thin layer of bone will also develop beneath the cartilage in the joints. The person may experience stiffness or joint pain. The area around the knee joint may start to feel particularly stiff and uncomfortable after a person has been sitting for extended periods. Though there may be some minor damage, the bones are not rubbing or scraping against each other. Synovial fluid is present, and it helps to reduce friction and support the movement of the knee.
Stage 3: Moderate
The damage to the cartilage has progressed, the gap between the bones has narrowed, and X-rays will show cartilage loss. Pain and discomfort may occur while performing daily activities, such as running, walking, kneeling, and bending. There may be early signs of joint inflammation.
As OA progresses, the cartilage will continue to thin and break down. The bones will respond by thickening and growing outward to form lumps. The tissue that lines the joint will become inflamed, and it may produce extra synovial fluid, resulting in increased swelling. This is called synovitis, and it is commonly known as water on the knee.
Stage 4—Severe
Knee replacement surgery for OA of the knee. Knee replacement surgery may be the only option for late-stage OA of the knee. This is the most advanced stage of OA, and the symptoms are very visible. The space between the bones in the joint has continued to narrow, causing the cartilage to break down further. As a result, there is stiffness in the joint, constant inflammation, and less fluid around the joint. There is more friction in the joint and more significant pain and discomfort while moving. X-rays will show bone on bone, meaning that either the cartilage has completely worn away or there is very little left. The individual will likely develop more bone lumps and experience pain that is often intense during simple activities, such as walking. In severe cases, the bones may become deformed and angulated because of asymmetric loss of cartilage. At this stage, surgical treatment is often the only option.
Medical provider diagnoses of ICD-9-CM 715 [osteoarthrosis and allied disorders] include the following definitions: 1) strict=ICD-9-CM 715; 2) expanded=ICD-9-CM 715, 716 [other and unspecified arthropathies], OR 719 [other and unspecified disorders of joint]); and 3) probable=strict OR expanded+respondent-reported prior diagnosis of OA or other arthritis excluding rheumatoid arthritis (RA).
Mechanisms of Resistance to Reverse Transcriptase Inhibitors
While NRTIs are effective at terminating DNA synthesis and HIV replication, HIV can and eventually does develop mechanisms that confer the virus resistance to the drugs. HIV-1 RT does not have proof-reading activity. This, combined with selective pressure from the drug, leads to mutations in reverse transcriptase that make the virus less susceptible to NRTIs and NNRTIs.
NRTI Resistance
There are two major mechanisms of NRTI resistance. The first being reduced incorporation of the nucleotide analog into DNA over the normal nucleotide. This results from mutations in the N-terminal polymerase domain of the reverse transcriptase that reduce the enzyme's affinity or ability to bind to the drug. A prime example for this mechanism is the that confers resistance to lamivudine (3TC) and emtricitabine (FTC). Another well characterized set of mutations are found in multi-drug resistant HIV which decreases reverse transcriptase's efficiency at incorporating NRTIs, but does not affect natural nucleotide incorporation. A virus with the mutation is intermediately resistant to zidovudine (AZT), didanosine (ddl), zalcitabine (ddC), stavudine (d4T), and slightly resistant to abacavir (ABC). A virus with the mutation complexed with the other four mutations becomes highly resistant to the above drugs, and is additionally resistant to lamivudine (3TC) and emtricitabine (FTC).
The second mechanism is the excision or the hydrolytic removal of the incorporated drug or pyrophosphorlysis. This is a reverse of the polymerase reaction in which the pyrophosphate/PPI released during nucleotide incorporation reacts with the incorporated drug (monophosphate) resulting in the release of the triphosphate drug.
NTRIs and Treatment of OA
Osteoarthritis (OA) is an age-associated or post-traumatic degenerative joint disease involving articular cartilage degradation, chronic inflammation, and bone remodeling (Berenbaum, F. Osteoarthritis and cartilage/OARS, Osteoarthritis Research Society 21, 16-21 (2013)). While aging is a primary cause, it can also be caused by post-traumatic joint injury (PTOA) (Gelber, A. C., et al. Ann Intern Med 133, 321-328 (2000) and Lohmander, L. S., et al. Am J Sports Med 35, 1756-1769 (2007)). Although OA is a leading cause of disability in the elderly, there is no FDA approved disease modifying osteoarthritis drugs (DMOADs) currently. Transposons were first discovered in plant and defined as “jumping genes” (Mc, C. B. Proc Natl Acad Sci USA 36, 344-355 (1950)). They were subsequently discovered in all eukaryotes including animals and human (de Koning, A. P., et al. PLoS Genet 7, e1002384 (2011)). While human functional protein-coding exons consist merely 1% of our genome, transposons make nearly half of our genome (de Koning, A. P., et al. PLoS Genet 7, e1002384 (2011)). L1, comprising 17% of entire genome, is the only active retrotransposon (Ostertag, E. M. & Kazazian, H. H., Annu Rev Genet 35, 501-538 (2001), Hancks, D. C. & Kazazian, H. H., Jr. Curr Opin Genet Dev 22, 191-203 (2012), Levin, H. L. & Moran, J. V. Nat Rev Genet 12, 615-627 (2011), Burns, K. H. & Boeke, J. D. Cell 149, 740-752 (2012), and Roman-Gomez, J., et al Oncogene 24, 7213-7223 (2005)). While it is active in germlines causing 124 genetic diseases, it is normally repressed in somatic cells and hence its function remains largely unknown (O'Donnell, K. A et al. Developmental cell 15, 179-181 (2008), Metzner, M., et al. PloS one 7, e49358 (2012), Faulkner, G. J. PLoS Genet 9, e1003944 (2013), Morrish, T. A., et al. Nature 446, 208-212 (2007), Morrish, T. A., et al. Nature genetics 31, 159-165 (2002), Guo, H., et al. Nature communications 5, 5276 (2014), and Moldovan, J. B. et al. PLoS Genet 11, e1005121 (2015)). Recently, it has been proposed that L1 plays a role in cell senescence, organism aging and neoplasia (Hancks, D. C. & Kazazian, H. H., Jr. Curr Opin Genet Dev 22, 191-203 (2012), De Cecco, M., et al. Aging Cell 12, 247-256 (2013), De Cecco, M., et al. Aging (Albany N.Y.) 5, 867-883 (2013), Marco De Cecco, et al. Nature in press (2018), and Hancks, D. C. & Kazazian, H. H., Jr. Mob DNA 7, 9 (2016)). Thus, as an aging associated disease, OA was hypothesized to be correlated with L1 activation in cartilage joint.
The invention provides a solution to obstacles associated with prevention and treatment of cartilage degenerative diseases. Accordingly, the invention includes methods using NRTIs to prevent, alleviate and treat cartilage degenerative diseases. Also provided herein are methods of using NRTIs for treatment of injury induced OA (also known as post-traumatic OA).
Accordingly, in some aspects, provided herein are methods for characterization of pharmaceutic efficacy in regards to alleviation OA markers and inflammatory markers. For example, the individual is diagnosed with OA, post-traumatic OA, rheumatoid arthritis, chondromatosis, costochondritis, relapsing polychondritis, herniation, chondrolysis, achondroplasia, chondrodysplasia, chondroma, chondrosarcoma, growth plate fracture and deformity, bone fracture, bone cyst, bone spur (osteophytes), bone tumor, craniosynostosis, fibrodysplasia, ossificans progressive, fibrous dysplasia, hypophosphatasia, metabolic bone disease, Paget's disease of bone, osteochondritis dissecans, osteogenesis imperfect, osteomalacia, osteopenia, osteoporosis. In experiments described herein, NRTIs are dissolved using autoclaved double distilled water. The individual to be treated is a human being; however, other subjects such as a mouse, rat, companion animals, such as a dog or a cat or working/performance animals such as a horse or a cow is also treated using the methods. RTIs suppress Long interspersed nuclear elements 1 (LINE-1, LINE1) (also, L1, Line1 and Line-1), Interferon (Inf-α) and Interleukin-6 (also IL6 and IL-6) in chondrocytes.
3TC suppresses Line-1 activities and prevent primary OA development in mice since miR-365/Line-1 axis correlates with OA development in both human OA samples and art-recognized mouse OA models Inhibition of Line-1 activity prevents and/or rescue OA onset. The class of drugs termed NRTIs are useful to treat OA pathogenesis.
To test whether NRTIs can inhibit OA markers via suppressing Line-1 in chondrocytes, human and mouse chondrocytes were treated with various concentrations of 3TC. qPCR analysis shows 3TC suppresses Line-1, Inf-α, Adamts5, Col10 expressions yet promotes Col2 expression in mouse chondrocytes. In human chondrocytes, whilst 3TC inhibits LINE-1, IHH, COL10 and ADAMTS5 expressions, 3TC promotes ACAN expression. Since Col10, Ihh and Mmp13 are induced in the articular cartilage of miR-365 Tg mice, human chondrocytes that already over-express miR-365 were treated with various concentrations of 3TC. Upon transfection, 3TC completely abolishes the miR-365 induced up-regulation of LINE-1, ADAMTS5, IHH and COL10 and rectifies ACAN suppression by miR-365.
Experiments were carried out to determine whether 3TC treatment rescues miR-365 induced Line-1 OA markers up-regulation and to determine whether 3TC can rescue OA phenotypes in primary OA model observed in miR-365 Tg mice. Starting at 2-month old, miR-365 Tg and age matched control mice (Cre only) were treated with 3TC dilution water or saline diluted water for 4 months before sacrifice. Consistently, proteoglycan loss was observed in the articular surface of miR-365 treated with saline but not of 3TC treatment. Furthermore, Line-1, Inf-α, Col10 and Adamts5 expression were significantly inhibited by 3TC treatment in miR-365 Tg mice. However, IL-6 or Acan levels are unchanged. miR-365 expression is also suppressed by oral 3TC treatment specifically in miR-365 Tg mice. Taken together, the data elucidates 3TC treatment, by inhibiting Line-1 activity, reverses Col2 lineage cell specific miR-365 over-expression induced OA markers including Col10 and Adamts5 in vivo.
3TC and FTC Prevent DMM (Destabilization of Medical Meniscus) Induced OA
Another cytidine analogue, FTC was tested. Although FTC suppresses Line-1 and Inf-α as well as inflammasome pathway like P2rx7 and Nlrp3, it induces Mmp3, Mmp13, Adamts5 and Col10 expressions whilst promotes Col2 and Acan expressions in mouse PC. 3TC was found to preferably inhibit OA markers while promoting ECM synthesis while FTC promotes both OA markers and ECM synthesis simultaneously in vitro.
The effects of 3TC and FTC using ex vivo femur organ cultures were tested. Intact femur was isolated from 21-day old WT mice into complete medium containing 3TC or FTC and was performed qPCR analysis using RNAs peeled from femur articular cartilages after 48 hrs incubation. While 3TC inhibits Line-1, Mmp13, Adamts5 and Col10, FTC inhibits Mmp13 and Adamts5 expressions. 3TC induced Col2 and Acan expressions when FTC induces the latter. Collectively, the data indicates that 3TC and/or FTC is useful to treat OA.
To test whether NRTIs can rescue secondary OA model, 12956 mice underwent either DMM or Sham surgeries with 3TC or FTC diluted water respectively from 8 weeks old for a total of 4 weeks. No appreciable difference of body weights between drug and control treatment groups are noticed. During histology assessment, treatment with 3TC and/or FTC treatments effectively prevented DMM induced proteoglycan loss in surgical knees. Meanwhile, qPCR analysis confirmed Line-1 inhibition introduced by 3TC and FTC. Chondrolytic markers including Mmp13, Adamts5 and hypertrophic maker Col10 were significantly repressed in 3TC and FTC treated DMM groups comparing with Saline treatment. Both 3TC and/or FTC treatments significantly prohibited miR-365 induction by DMM, indicating that NRTIs acts up-stream of miR-365. The data indicate that NTRIs such as 3TC and FTC prevent secondary OA onset by inhibiting Line-1 up-regulation and repressing OA markers.
miR-365 was found to target retrotransposable element suppressors including Dicer, Prkdc and Sqstm1. Through this circuit, miR-365 controls Line-1 expression thereby promoting cartilage degradation. Suppressing Line-1 expression using NRTIs, for example 3TC and FTC, through their anti-reverse transcriptional functions, prevents cartilage degradation and results in OA phenotype rescue.
The following materials and methods were used to generate the data and observations described herein.
Animals
To over-express miR-365 in cartilage tissues, C57BL/6 background miR-365fl/wt transgenic mice are crossed with Col2a1-Cre+/wt (Cre-only) mice to generate Col2a1-Cre+/wt; miR-365fl/wt mice (miR-365 Tg) (Yang, K., et al. Connect Tissue Res 58, 103-115 (2017)).
12956/SvEv strain male mice are purchased from Taconic (https://www.taconic.com/mouse-model/129s6) at their age of 7-week-old. At least 3-day (72-hrs) acclimation period must be given to mice before any further procedures occurred to them.
All strains of mice are housed with ad libitum access to food and water unless otherwise stated.
Genotyping
Genomic DNA is extracted from mouse toes or tails within 7 days after birth and performed by conventional PCR using Hot start Taq polymerase (New England BioLabs, Cat. M049S/L) using primers designed specific to miR-365 insertion or Col2a1-Cre constructs.
Mouse Model of Destabilization of Medial Meniscus (DMM)
129S6/SvEv male mice are chosen for experimental subjects at their age of 8-week-old. To create mouse injury/trauma induced osteoarthritis model, medial meniscus ligament is transected using a previously described. 8-week-old male mice are anesthetized using either intraperitoneal (IP) injection of Ketamine/Dexmedetomidine or isoflurane to carry out medial parapatellar arthrotomy. Transection is made with a stab knife (Sharpoint™, Cat. 72-1551). At Weeks 12, mice are euthanized and dissected for histological examination as well as cartilage RNA extraction. 12 mice are used for each group/time point.
Human Specimens
Cartilages are obtained from individuals diagnosed with OA and underwent total knee replacement. Samples are harvested freshly after surgeries. Pictures of specimens are taken for recording purpose. OA lesion and non-lesion areas are empirically identified by orthopedic surgeons based on direct observation. For each site of interest, a 1×1 mm2 tissue with a depth ranging from 4-8 mm is harvested using sterile, RNase free Rib-Back® scalpels (Bard-Parker®, Cat. 371115) manually. Care must be taken to avoid any subchondral bone. To obtain maximal digestion efficacy, resected specimens are further minced by scalpels before submerging into 350 mL QIAzol Lysis Reagent (Qiagen, Cat No./ID: 79306). Specimens can either be stored at −80° C. or be accessed using diverse methods.
Femur Explant Organ Culture
Femurs are obtained from 21-day-old WT C57BL/6 mice. Femurs with intact articular surface and periosteum is sterilely dissected under microscope. All animal procedures are reviewed and approved by IACUC. Upon harvesting, femurs are rinsed with HB SS (Gibco®, Grand Island, N.Y. 14072 USA) and then submerged into DMEM (Gibco®, Grand Island, N.Y. 14072 USA) medium supplemented with 10% fetal bovine serum (FBS, Gibco®, Grand Island, N.Y. 14072 USA) in 12-well culture dishes. 3TC or FTC is added into the medium with desired concentrations. After a total of 48 hrs incubation at 37° C. in an atmosphere of 5% CO2, femurs are rinsed with HBSS and articular cartilage is peeled off using surgical scalpels under dissecting microscope for RNA extraction.
Histology, Immunohistochemistry (IHC), and Immunofluorescence
Human cartilage tissues are fixed in 4% Paraformaldehyde (PFA) for 24 hrs at 4° C., followed by 30% DEPC-sucrose (Sigma, Cat. 50289-500G, St. Louis, Mo. 63103 USA) at 4° C. until the specimens are sunken to the bottom of the containers. Tissues are embedded in optimal cutting temperature compound (O.C.T., SAKURA FINETEK USA INC, Tissue-Tek® O.C.T. Compound, Cat. 4583). A cryo-section microtome (Model: CM3050, Leica, Germany) is used to cut 6-μm-thick sections. The sections are stained by H&E staining to assess morphology. Mouse tissues are fixed in 10% formalin for 24-48 hrs depending on tissue size, followed by de-calcification process using DEPC de-calcification reagents (Ethylenediaminetetraacetic acid, Sigma, Cat. EDS-1KG, St. Louis, Mo. 63103 USA) at room temperature for 10-14 days. After de-calcification, tissues are dehydrated in ethanol before embedded in paraffin with routine procedures. A microtome (Model: FINESSE ME, Thermo Shandon, UK) is used to cut 6-μm-thick sections. For every 80 μm interval, 5 sister sections are harvested to make a total of 13-16 slices from one knee of a fully-grown mouse. Number of slides form one knee may vary due to varying sizes of the specimens. Slides are then de-paraffinized and stained GAG with Alcian blue (Sigma, Cat. A3157-10G) or Safranin O (Sigma, Cat. 58884-25G, St. Louis, Mo. 63103 USA). Morphology is assessed by H&E staining. For IHC, paraffin sections are processed with routine procedures instructed by Histostain® Plus 3rd Gen IHC Detection Kit (Life Technologies, Cat. 859673, Frederick, Md. 21704 USA). Rabbit or mouse antibodies specifically against antigens of interest are used, followed by incubation of HRP-conjugated secondary antibodies against rabbit or mouse IgG (provided by the kit). Primary and secondary antibodies are listed herein. Signals are then visualized by a DAB-Plus Substrate Kit (Life Technologies, Cat. 002020, Frederick, Md. 21704 USA).
Safranin O Staining
Paraffin sections are de-paraffinized in 2 changes of xylene, 10 mins each, followed by re-hydration in 2 changes of 100% alcohol, 5 mins each; 2 changes of 95% alcohol, 5 mins each; 70% alcohol for 5 mins. Sections are then rinsed in running tap water for 2 mins before stained with 0.4% fast green solution (Sigma, Cat. F-7258, St. Louis, Mo. 63103 USA) for 2 mins however the latter timing must be empirically controlled to assure desired coloration. Stained sections are then quickly rinsed with 1% acetic acid solution (Sigma, Cat. 695092-500ML-GL, St. Louis, Mo. 63103 USA) for no more than 10-15 sec. 0.1% Safranin O Solution is used for staining proteoglycan however the actual timing must be carefully determined based on actual coloring condition, for maximally 10 mins. After Safranin O staining, sections are submerged in 2 changes of 95% alcohol, 2 mins each, 2 changes of 100% alcohol, 2 mins each for de-hydration. Lastly, sections are cleared in 2 changes of xylene, 2 mins each, and mounted using resinous mounting medium (ACRYMOUNT™, Cat. SL80-4, McKinney, Tex. 75069 USA).
OARSI Scoring
To histologically evaluate OA severity, we quantified Safranin O stained knee sections according to OARSI semi-quantitative system as previously described (Sato, S., et al. TheScientificWorldJournal 2014, 685854 (2014)).
Hematoxylin and Eosin (H&E) Staining
Paraffin sections are de-paraffinized in 2 changes of xylene, 10 mins each, followed by re-hydration in 2 changes of 100% alcohol, 5 mins each; 2 changes of 95% alcohol, 5 mins each; 70% alcohol for 5 mins. Sections are then rinsed in running tap water for 2 mins before stained in Mayer's Hematoxylin solution (NovaUltra™ H&E Stain Kit, IHCWORLD, Cat. IW-3100) for 2 mins however the latter timing must be empirically controlled to assure desired coloration. Stained sections are then rinsed in running tap water for 5 mins before dipped into 95% alcohol for 10 times or 30 sec based on performer's preference. Eosin Solution (NovaUltra™ H&E Stain Kit, IHCWORLD, Cat. IW-3100) is used for counterstaining however the actual timing must be carefully determined based on actual coloring condition. After counterstaining, sections are dipped in 95% alcohol for 2 times before transferred through 2 changes of 100% alcohol, 5 mins each for de-hydration. Lastly, sections are cleared in 2 changes of xylene, 5 mins each, and mounted with resinous mounting medium.
For frozen sections, procedures are similar with the exception between Eosin counterstaining and 95% alcohol dipping steps. Instead, during these two steps, frozen sections must be air dried for 30 mins at room temperature and fixed in 10% formalin for 10 mins. Then the sections are taken out for another 30 mins air dry at room temperature before rinsed in water.
Homogenization
A PowerGen 125 (Fisher Scientific, Cat. 03.349248) is used to homogenize samples for RNA exaction. A cycle of 45″ homogenization at speed of 5, followed by a cool down step of 15″ is repeated for 5 cycles before switching to a finer drill for the same cycles. Drills/PowerGen Generator (Fisher Scientific, Cat. 14-261-15) are rinsed in DEPC-water followed by 100% ethanol rinse between different specimens to avoid cross contamination. All procedures are taken place on ice to avoid RNA degradation due to heat.
Primary Growth Plate/Articular Chondrocytes (PCs) Culture
Rib cages are sterilely isolated from neonatal mice (within 7-day-old) of desired genotypes and rinsed with HBSS for five times. To remove unspecific tissues, rib cages are digested in Collagenase D (3 μg/mL, Roche, Cat. 11088882001, Mannheim, Germany) for 2-4 hrs at 37° C. and rinsed with HBSS (Gibco®, Grand Island, N.Y. 14072 USA) for five times to remove detached unspecific tissues. To detach chondrocytes from rib cages, the samples undergo secondary digestion in Collagenase D (3 μg/mL) for at least 4 hrs at 37° C. with constant agitation (200 rpm). Detached chondrocytes are palleted to remove excessive Collagenase D and resuspended in complete medium of DMEM (Gibco®, Grand Island, N.Y. 14072 USA) which contains 10% FBS, 100 U/mL penicillin and 100 μg/mL streptomycin (Gibco®, Grand Island, N.Y. 14072 USA). Growth plate PCs are grown at 37° C. in an atmosphere of 5% CO2. The media is changed on the following day to remove remaining Collagenase D and every 3 days thereafter.
Similarly, articular cartilages are sterilely isolated under dissection microscope from neonatal mice (within 7-day-old) of desired genotypes and rinsed with HBSS for five times. To remove unspecific tissues, articular cartilages are minced and digested in Collagenase D (3 μg/mL) for 2 hrs at 37° C. and rinsed with HBSS for five times to remove detached unspecific tissues. To detach chondrocytes from cartilage matrix, the samples underwent secondary digestion in Collagenase D (3 μg/mL) for at least 4 hrs at 37° C. with constant agitation (200 rpm). Detached chondrocytes are palleted to remove excessive Collagenase D and resuspended in complete medium of DMEM which contains 10% FBS, 100 U/mL penicillin and 100 μg/mL streptomycin. Articular PCs are grown at 37° C. in an atmosphere of 5% CO2. The media is changed on the following day to remove remaining Collagenase D and every 3 days thereafter.
Transient Transfection
Cells are seeded onto desired size plates to reach 70-90% confluence and transfected with miR-365 mimic or miRNA mimic negative control or miR-365 inhibitor or inhibitor negative control (Dharmacon®, Lafayette, Colo., USA). Lipofectamine 3000 (Invitrogen®, Waltham, Mass., USA) is used as transfection reagents. Medium is changed 24 hrs after transfection. 48 hrs post transfection, cells are lysated in either QIAzol for RNA purification and real-time PCR analysis or ice-cold lysis buffer containing protease inhibitor and phosphatase inhibitor for western blot analysis. MiR-365 mimic, miRNA mimic negative control, miR-365 inhibitor and inhibitor negative control are typically used at a final concentration of 25 nM unless otherwise stated.
Quantitative Real-Time PCR (qPCR)
Both miRNA and mRNA are extracted using miRNeasy Mini Kit (Qiagen®, Germantown, Md., USA) and reversely transcribed using miScriptIIRT Kit (Qiagen®, Germantown, Md., USA) according to manufacturer's instruction. qPCR is performed using SYBR Green PCR master mix (Qiagen®, Germantown, Md., USA) on a Bio-Rad CFX96 real-time PCR detection system (Bio-Rad®, Hercules, Calif., USA). Amplification conditions are as follows: 95° C. for 10 min, 40 cycles of 95° C. for 10 sec, 55° C. for 30 sec, and 72° C. for 30 sec. Sense and antisense primers are provided herein. 18S ribosomal or Gapdh RNA is used as an internal control gene to normalize the mRNAs level. The ubiquitously expressed snRNA U6 is used as an endogenous control for miRNAs level. Primers are synthesized by Integrated DNA Technologies (http://www.idtdna.com). The primers for miR-365 are purchased from Qiagen. Fold changes of mRNA and miRNAs are calculated by the 2{circumflex over ( )}(−ΔΔCt) method and normalized to 18S/Gapdh or U6 snRNA, respectively.
Prediction of miR-E365 Target Genes
Targets of miR-365-5p and miR-365-3p were identified using the TargetScan (http://www.targetscan.org/) and miRanda/mirSVR (http://34.236.212.39/microrna/home.do) target prediction algorithms.
Plasmid Construction
WT Aicda, Dicer1, Prkdc, Sqstm1 and Zc3hav1 3′UTRs bearing potential response elements (REs) serving as miR-365 seeding sites predicted by microrna.org are cloned from mouse genomic DNA (50 ng-250 ng) using primers designed to introduce ideal restriction enzyme cleavage sites according to the backbone plasmid pmirGLO construct (Promega, Madison, Wis., USA). Detailed thermal cycles are: 98° C. for 30 sec, 25-35 cycles of 98° C. for 10 sec, 55-60° C. for 30 sec, and 72° C. for 15 sec and final extension at 72° C. for 10 min before holding at 4° C. Designed primers are provided herein. PmeI and XhoI are enzymes used to cleave for sticky ends. After restriction enzymes cleavage, approximately 500 bp 3′UTR sequences are annealed into pmirGLO construct (1 pg-10 ng). REs are mutated according to QuikChange Lightning Multi Site-Directed Mutagenesis Kit's instruction (Agilent, Cat. 210513/210515, Santa Clare, Calif. 95051 USA).
Luciferase Assays
ATDC5 cells are cultured at 2.5×104 cells/well in 24-well plates. The cells are co-transfected with miR-365 mimic (25 nM) or miRNA mimic negative control (25 nM) and 500 ng of pmirGLO-Dicer1/Zap/Sqstm1/Prkdc/Aicda 3′-UTR WT or Mut plasmids. Transfection is performed using Lipofectamine 3000 (Invitrogen, Cat. L3000-008, Carlsbad, Calif. 92008 USA) reagent. The assays are performed in triplicate unless otherwise stated. 24 hrs after transfection, cells are collected, and luciferase activity is determined using the Dual-Luciferase reporter assay system (Promega, Madison, Wis., USA) with the GLOMAX 20/20 luminometer (Model: 2031_000, Turner BioSystems, Sunnyvale, Calif. USA). Briefly, cells are rinsed with PBS and incubated with Passive Lysis Buffer (provided by the kit) for 15 mins with constant agitation at room temperature. Lysates are scraped into 1.5 mL Eppendorf tubes. 20 μl of lysates are fixed with 50 μl Luciferase Assay Buffer II to measure Firefly luciferase luminescence. 50 μl Stop & Glo buffer is then added to measure Renilla luminescence. The luciferase activity is represented by the ratio of Firefly/Renilla measurements.
Western Blot (WB)
All pre-treated samples are washed with ice-cold PBS and lysated in RIPA buffer (M-PER, Pierce, Ill.) plus protease inhibitor phenylmethylsulfonyl fluoride [Halt™, Thermo Scientific, Protease Inhibitor Single-Use Cocktail (100×), Cat. 78430] for 30 min on ice with constant agitation. The lysates are centrifuged at 12,000 g for 15 min at 4° C. The supernatants are collected, and the protein concentrations are determined using Pierce™ BCA assay (Thermo Scientific, Cat. 23225). Samples are mixed with equal volume 2× Laemmli sample buffer (Bio-Rad, Cat. 161-0737) which contains 2-Mercaptoethanol (Bio-Rad, Cat. 161-0710) and heated for 5 min at 100° C. to denature. Equal amount of proteins for each sample are separated by 8-12% SDS polyacrylamide gel depending on protein size of interest and then transferred to nitrolcellulous membrane (Bio-Rad, Cat. 162-0112) for 70 min at 100 V. The membrane is blocked with 5% bovine serum albumin (BSA, Sigma, Cat. A7906-50G) in 0.1% Tris-Buffered Saline-Tween 20 (TBS-T, BBP, Cat. IBB-581X) for 1 hr at room temperature, followed by incubation with primary antibodies against proteins of interest at 4° C. overnight. On the following day, the membrane is rinsed with TBS-T for 10 min for a total of 5 times and incubated with anti-rabbit-Alexa Fluor 680 (Molecular Probes, Eugene, Oreg., USA) for 1 hr at room temperature followed by TBS-T rinse for 10 min for a total of 5 times. The blots are then scanned using an Odyssey fluorescence scanner (LI-COR Biosciences, Lincoln, Nebr., USA) and quantitatively analyzed by ImageJ (https://imagej.nih.gov/ij/index.html).
Statistical Analysis
Data represents mean values SD (error bars). Statistical significance is calculated using student's t-test (unpaired) or ANOVA one-way test. There is a minimum of n≥3 for all groups unless otherwise stated.
MiR-365 Over-Expression Promotes Line-1 Activation in Human OA Lesion and Mouse OA Model
Human long interspersed element-1 (Line-1) has been an emerging biomarker of many human cancers and chronic diseases (Ostertag, E. M. & Kazazian, H. H., Jr. Annu Rev Genet 35, 501-538 (2001) and Birren, S. J., Lo, L. & Anderson, D. J. S. Development 119, 597-610 (1993)). Line-1 activation may be associated with cellular senescence (De Cecco, M., et al. Aging Cell 12, 247-256 (2013), and Ali, M., et al. Annals of the rheumatic diseases 62, 663-666 (2003)). Since OA is an aging associated chronic disease, studies were carried out to determine whether OA pathogenesis is companied by Line-1 activation.
qPCR analysis of RNA extracted from both lesion and non-lesion areas of human cartilages specimens shows Line-1 activities are significantly up-regulated in OA lesion areas in majority of the OA patients. Yet another abundant transposable element in human genome, Alu, which exploits the machinery encoded by Line-1 to transpose itself, exhibits no uniformed trends between lesion and non-lesion areas of human OA specimens. miR-365 expressions were up-regulated in 50% of samples, indicating an association between Line-1 and miR-365 up-regulation in OA.
To test whether miR-365 is sufficient to induce Line-1, we transfected mouse primary chondrocytes (PC) with miR-365 mimic. Upon transfection, the expression of Line-1 and Ihh, a chondrocyte hypertrophic marker, are significantly induced. siRNA against Line-1 successfully rescued the miR-365 led induction of Line-1 and Ihh, indicating that not only miR-365 is sufficiently to induce Line-1, but also Ihh could act downstream of induced Line-1 activity by miR-365.
To study the relationship between miR-365 and Line-1 in cartilage in vivo, we created transgenic mice of which miR-365 is specifically over-expressed in Col2 lineage cells (miR-365 Tg mice) (Yang, K., et al. Connect Tissue Res 58, 103-115 (2017))). We observed that miR-365 Tg mice manifest advanced onset of OA as early as at 6-month-old (Hug, B. A. Cell 119, 448-449 (2004)). Therefore, studies were carried out to determine whether Line-1 is elevated in miR-365 Tg mice. In alignment with miR-365 over-expression in cartilage, Line-1 RNA expressions are significantly up-regulated 4- and 6-month old. Besides promoting Line-1 expression, miR-365 cartilage over-expression also induces Ihh, Col10 and Mmp13 expressions in miR-365 Tg mice (Hug, B. A. Cell 119, 448-449 (2004)). Collectively, the in vivo data indicate miR-365 over-expression in cartilage drives long-term Line-1 and OA markers up-regulation which temporarily associates with OA phenotypic onset.
To test whether this causal relationship between miR-365 up-regulation and Line-1 activation exists in secondary OA model, we built injury induced OA model by performing DMM surgery on the right knees of 12956/SvEv male mice at 2 months old. One month post DMM surgery, Line-1 activities are significantly up-regulated in the destabilized right knees comparing with Sham knees. Same pattern of miR-365 increase is observed in the same knees. Consistently, significant proteoglycan loss quantified by blinded grades using OARSI scores (Sato, S., et al. TheScientificWorldJournal 2014, 685854 (2014)) is observed in DMM knees, corroborating that Line-1 activation is associated with miR-365 up-regulation as well as cartilage degradation. In addition, in C57BL/6 background WT mice which underwent DMM surgeries, Line-1 activation is tightly associated with miR-365 increase and such association is further augmented as post-surgical mice age. Hence the association between miR-365 and Line-1 up-regulation is valid in secondary OA models in mice.
MiR-365 Induces Line-1 Expression via Post-Transcriptional Suppressions of Prkdc, Dicer and Sqstm1
Bio-informatic search revealed five candidates (Aicda, Dicer, Prkdc, Sqstm1 and Zc3hav1) of potential miR-365 targets that are both conserved across species and involved in Line-1 suppression. As Line-1 activation can be induced by miR-365 over-expression in cartilage and such activation has been tightly associated with primary and secondary OA in human and mice, we are interested in whether above candidates' expressions are altered in OA tissues. qPCR analysis using human OA cartilage RNA showed DICER, PRKDC, SQSTM1 and ZAP expressions are decreased in majority of OA specimens while AICDA is not detectable in human cartilage. Only Prkdc is down-regulated at the RNA level in miR-365 Tg mice articular cartilage. To further confirm in vitro, we over-expressed miR-365 in mouse PC, to evaluate wither miR-365 increase in cartilage induces Line-1 activation via post-transcriptional suppression of Line-1 inhibitors.
Aicda (Faulkner, G. J. PLoS Genet 9, e1003944 (2013)), Dicer (Morrish, T. A., et al. Nature genetics 31, 159-165 (2002)V), Prkdc (Guo, H., et al. Nature communications 5, 5276 (2014)), Sqstm1 (Moldovan, J. B. & Moran, J. V. PLoS Genet 11, e1005121 (2015)) and Zc3hav1 (Erwin, J. A., et al. Nat Rev Neurosci 15, 497-506 (2014)) are shown to be involved in inhibition of Line-1 at various biogenesis stages. WB using proteins isolated from primary mouse chondrocytes transfected with miR-365 mimic and Sqstm1 cDNA demonstrates Line-1 is significantly induced by miR-365 transient over-expression and rescued by Sqstm1 over-expression, indicating Sqstm1 is involved in miR-365 over-expression induced Line-1 activation in cartilage. Furthermore, WB shows while Dicer protein expression is suppressed by miR-365 transfection, it is induced by miR-365 inhibitor, indicating that miR-365 affects Dicer expression at post-transcriptional level.
To further test whether Prkdc, Dicer and Sqstm1 are authentic targets of miR-365, we co-transfected ATDC5 cells with luciferase genes bearing predicted binding sites of WT 3′UTR of Aicda, Dicer, Prkdc, Sqstm1 and Zc3hav1 at 3′ ends as well as miR-365 mimic or mimic control respectively. Dicer, Prkdc and Sqstm1 WT 3′UTR luciferase reporter genes showed significant reduction of activities regarding to miR-365 over-expression and those reduction are completely abolished via site-directed mutagenesis of the predicted seeding sites. Hence Dicer, Prkdc and Sqstm1 are authentic targets of miR-365 in chondrocytes.
3TC Suppresses Line-1 Activities and Prevent Primary OA Development in Mice
Since miR-365/Line-1 axis snugly correlates with OA development in both human OA samples and mouse OA models, experiments were carried out to determine whether inhibition of Line-1 activity prevents or rescues OA onset. A class of drugs termed Reverse-transcriptase inhibitor (NRTI), which are popularly prescribed for controlling HIV and HBV infections attributing to their anti-retroviral function, can suppress retrotransposable elements activities in various models (Patnala, R., et al. Breast Cancer Res Treat 143, 239-253 (2014), Jones, R. B., et al PloS one 3, e1547 (2008), and Guilak, F. Best practice & research. Clinical rheumatology 25, 815-823 (2011)). However, prior to the invention, NRTI used to rescue OA pathogenesis had not been described.
To test whether NRTIs can inhibit OA markers via suppressing Line-1 in chondrocytes, we treated human and mouse chondrocytes with various concentrations of 3TC. qPCR analysis shows 3TC suppresses Line-1, Inf-α, Adamts5, Col10 expressions yet promotes Col2 expression in mouse chondrocytes. In human chondrocytes, whilst 3TC inhibits LINE-1, IHH, COL10 and ADAMTS5 expressions, 3TC promotes ACAN expression. Since Col10, Ihh and Mmp13 are induced in the articular cartilage of miR-365 Tg mice, we treated human chondrocytes that already over-express miR-365 with various concentrations of 3TC. Upon transfection, 3TC completely abolishes the miR-365 induced up-regulation of LINE-1, ADAMTS5, IHH and COL10 and rectifies ACAN suppression by miR-365.
Because 3TC treatment rescues miR-365 induced Line-1 OA markers up-regulation, we tested whether 3TC can rescue OA phenotypes in primary OA model observed in miR-365 Tg mice. Starting at 2-month old, miR-365 Tg and age matched control mice (Cre only) are treated with 3TC dilution water or saline diluted water for 4 months before sacrifice. Consistently, proteoglycan loss is observed in the articular surface of miR-365 treated with saline but not of 3TC treatment. Furthermore, Line-1, Inf-α, Col10 and Adamts5 expressions are significantly inhibited by 3TC treatment in miR-365 Tg mice. However, IL-6 or Acan levels are unchanged. miR-365 expression is also suppressed by oral 3TC treatment specifically in miR-365 Tg mice. The data elucidates 3TC treatment, by inhibiting Line-1 activity, can appreciably reverse Col2 lineage cell specific miR-365 over-expression induced OA markers including Col10 and Adamts5 in vivo.
3TC and FTC Prevent DMM Induced OA
In the light of the promising anti-OA activity of 3TC, we evaluated another widely prescribed cytidine analogue, FTC. Although FTC suppresses Line-1 and Inf-α as well as inflammasome pathway like P2rx7 and Nlrp3, it induces Mmp3, Mmp13, Adamts5 and Col10 expressions whilst promotes Col2 and Acan expressions in mouse PC. Taken together, 3TC preferably inhibits OA markers while promoting ECM synthesis, while FTC promotes both OA markers and ECM synthesis simultaneously in vitro.
Next, we tested the effects of 3TC and FTC using ex vivo femur organ cultures. We incubated intact femur isolated from 21-day old WT mice into complete medium containing 3TC or FTC and performed qPCR analysis using RNAs peeled from femur articular cartilages after 48 hrs incubation. While 3TC consistently does a promising job in terms in inhibiting Line-1, Mmp13, Adamts5 and Col10, FTC inhibits Mmp13 and Adamts5 expressions. 3TC induces Col2 and Acan expressions when FTC induces the latter. Collectively, the data further indicates the potential anti-OA role of 3TC and FTC.
To test whether NRTIs can rescue secondary OA model, we treated 12956 mice which underwent either DMM or Sham surgeries with 3TC or FTC diluted water respectively from 8 weeks old for a total of 4 weeks. No appreciable difference of body weights between drug and control treatment groups were noticed. During histology assessment, we found both 3TC and FTC treatments effectively prevent DMM induced proteoglycan loss in surgical knees. Meanwhile, qPCR analysis confirmed Line-1 inhibition introduced by 3TC and FTC. Chondrolytic markers including Mmp13, Adamts5 and hypertrophic maker Col10 are significantly repressed in 3TC and FTC treated DMM groups comparing with Saline treatment. Both 3TC and FTC treatments significantly prohibit miR-365 induction by DMM, providing intriguing hints that NRTIs may act up-stream of miR-365. Therefore, 3TC and FTC prevents secondary OA onset by inhibiting Line-1 up-regulation and repressing OA markers.
The data indicate that miR-365 targets retrotransposable element suppressors including Dicer, Prkdc and Sqstm1. Through this circuit, miR-365 controls Line-1 expression thereby promoting cartilage degradation. Suppressing Line-1 expression using NRTIs, for example 3TC and FTC, through their anti-reverse transcriptional functions, prevents cartilage degradation and results in OA phenotype rescue.
Osteoarthritis is Treated by Inhibiting MicroRNA Up-Regulation of Retrotransposon LINE-1
Prior to the invention, retrotransposable element activation has not been associated with OA pathogenesis. Our results for the first time unearth the correlation between OA development and Line-1 activation in both human OA specimens and mouse in vivo models.
OA is a multi-factor as well as polygenic disease as etiology indicates there is no single cause of OA pathogenesis (Birren, et al. Development 119, 597-610 (1993)). Human OA specimens are of heterogeneous etiologies as the entire information of human donors are difficult to trace back. The up-regulation of miR-365 and activation of Line-1 are consistent in majority of the human OA specimens, indicating the strong association between these two exists in most human cases. As Line-1 activation may also correlate with aging (De Cecco, M., et al. Aging Cell 12, 247-256 (2013), Ali, M., et al. Annals of the rheumatic diseases 62, 663-666 (2003)), given that the human donors are of various ages, the basal Line-1 levels are difficult to unify. Yet OA development in WT mouse hardly occur. miR-365 Tg mice represent mono-factor OA model which is specifically triggered by the over-expression of miR-365 in Col2-lineage cells, which comprise the most population in cartilage. In addition, all mouse experimental subjects are age- and gender-matched, thus making rodent results more uniform and more consistent between individual subjects. The art recognized mouse models described herein are indicative of the human disease/disorder.
Data from miR-365 Tg mice treated with 3TC indicates 3TC inhibits Col10 and Adamts5 expressions specifically via suppressing Line-1 pathways as IL-6 expressions, which is a down-stream gene of miR-365, are left unchanged. miR-365 and Line-1 expressions are significantly suppressed by 3TC specifically in miR-365 Tg. miR-365 expression is significantly suppressed by 3TC and FTC in DMM induced OA models. The data indicate that NRTIs affect miR-365 expression. For example 3TC and FTC treatments specifically suppress supra-physical miR-365/Line-1 expressions in non-injury OA model, because physical miR-365 expression is required during mechanical signal transduction, which is a good indicator for the effective usage of 3TC and FTC in treating both primary and secondary OA without delivering adverse effects.
Both siLine-1 and 3TC suppress not only Line-1 but also Ihh in vitro while 3TC suppresses only Line-1 but not Ihh in vivo. This difference may be attributed to contrast between in vitro condition and in vivo environment. For instance, PC are isolated from neonatal mice while in vivo 3TC treatment are conducted in near fully developed mice from 2-month old till 6-month old when the qPCRs are performed. The effect of Line-1 inhibition in chondrocytes at different stages might be various. Furthermore, while the former experiment is transient, the latter is a long-term treatment. Last but only least, 3TC treatment, beyond inhibiting Line-1 specifically, might alter other pathways. Ihh pathway might parallel with Line-1 pathway in cartilage in vivo, at least during long-term 3TC treatment. Similar explanation may also underly miR-365 induced Mmp13 results.
In this study, we have demonstrated a regulatory role for miR-365 through inducing retrotransposable element, Line-1, to promote OA pathogenesis. In order to reduce the severity of and/or prevent OA, feasible methods to suppress Line-1 including administration of 3TC and FTC and siRNA against Line-1 are useful as therapeutic approaches in counteracting osteoarthritis.
Pharmaceutical Compositions
The present invention provides also pharmaceutical compositions comprising a nucleoside reverse transcriptase inhibitor (NRTI) (e.g., 3TC or FTC) and at least one pharmaceutically acceptable excipient or carrier. In examples, the pharmaceutical composition comprises an effective amount of the NRTI (e.g., 3TC or FTC) as described herein in connection with the methods of the invention.
In one embodiment, the composition (e.g., a composition comprising an NRTI) is further combined with at least one additional therapeutic agent in a single dosage form.
The term “pharmaceutically acceptable” refers to those compounds, materials, compositions, carriers, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio.
“Pharmaceutically acceptable excipient” means an excipient that is useful in preparing a pharmaceutical composition that is generally safe, non-toxic and neither biologically nor otherwise undesirable, and includes excipient that is acceptable for veterinary use as well as human pharmaceutical use. Examples of pharmaceutically acceptable excipients include, without limitation, sterile liquids, water, buffered saline, ethanol, polyol (for example, glycerol, propylene glycol, liquid polyethylene glycol and the like), oils, detergents, suspending agents, carbohydrates (e.g., glucose, lactose, sucrose or dextran), antioxidants (e.g., ascorbic acid or glutathione), chelating agents, low molecular weight proteins, or suitable mixtures thereof.
A pharmaceutical composition can be provided in bulk or in dosage unit form. It is especially advantageous to formulate pharmaceutical compositions in dosage unit form for ease of administration and uniformity of dosage. The term “dosage unit form” as used herein refers to physically discrete units suited as unitary dosages for the subject to be treated; each unit containing a predetermined quantity of active compound calculated to produce the desired therapeutic effect in association with the required pharmaceutical carrier. The specification for the dosage unit forms of the invention are dictated by and directly dependent on the unique characteristics of the active compound and the particular therapeutic effect to be achieved. A dosage unit form can be an ampoule, a vial, a suppository, a dragee, a tablet, a capsule, an IV bag, or a single pump on an aerosol inhaler.
For treatment of articulating joint disorders such as OA (or RA-rheumatoid arthritis), the NRTIs are administered intra-articularly (directly into a joint), intravenously, orally, or transcutaneously.
The parenteral and/or intra-articular preparation can be enclosed in ampules, disposable syringes or multiple dose vials made of glass or plastic. Intra-articular administration is useful for local treatment of disease and flare-up, e.g. pain in joints, osteoarthritis, synovitis and the like. A complex of the present invention may also be administered as a bolus, electuary or paste. Exemplary administrations include: Intra-articular, Peri-articular, Intra-bursal, Intra-muscular, or Soft tissue—tendon ruptures. Exemplary administration volumes for adult human are shown below, and are proportionally smaller for a human child.
In therapeutic applications, the dosages vary depending on the agent, the age, weight, and clinical condition of the recipient patient, and the experience and judgment of the clinician or practitioner administering the therapy, among other factors affecting the selected dosage. Generally, the dose should be a therapeutically effective amount. Dosages can be provided in mg/kg/day units of measurement (which dose may be adjusted for the patient's weight in kg, body surface area in m2, and age in years). Exemplary doses and dosages regimens for the compositions in methods of treating muscle diseases or disorders are described herein.
The pharmaceutical compositions can take any suitable form (e.g., liquids, aerosols, solutions, inhalants, mists, sprays; or solids, powders, ointments, pastes, creams, lotions, gels, patches and the like) for administration by any desired route (e.g., pulmonary, inhalation, intranasal, oral, buccal, sublingual, parenteral, subcutaneous, intravenous, intramuscular, intraperitoneal, intrapleural, intrathecal, transdermal, transmucosal, rectal, and the like). For example, a pharmaceutical composition of the invention may be in the form of an aqueous solution or powder for aerosol administration by inhalation or insufflation (either through the mouth or the nose), in the form of a tablet or capsule for oral administration; in the form of a sterile aqueous solution or dispersion suitable for administration by either direct injection or by addition to sterile infusion fluids for intravenous infusion; or in the form of a lotion, cream, foam, patch, suspension, solution, or suppository for transdermal or transmucosal administration.
In embodiments, the pharmaceutical composition comprises an injectable form.
A pharmaceutical composition can be in the form of an orally acceptable dosage form including, but not limited to, capsules, tablets, buccal forms, troches, lozenges, and oral liquids in the form of emulsions, aqueous suspensions, dispersions or solutions. Capsules may contain mixtures of a compound of the present invention with inert fillers and/or diluents such as the pharmaceutically acceptable starches (e.g., corn, potato or tapioca starch), sugars, artificial sweetening agents, powdered celluloses, such as crystalline and microcrystalline celluloses, flours, gelatins, gums, etc.
A pharmaceutical composition can be in the form of a sterile aqueous solution or dispersion suitable for systemic administration.
A pharmaceutical composition can be in the form of a sterile aqueous solution or dispersion suitable for administration by either direct injection or by addition to sterile infusion fluids for intravenous infusion, and comprises a solvent or dispersion medium containing, water, ethanol, a polyol (e.g., glycerol, propylene glycol and liquid polyethylene glycol), suitable mixtures thereof, or one or more vegetable oils. Solutions or suspensions of the compound of the present invention as a free base or pharmacologically acceptable salt can be prepared in water suitably mixed with a surfactant. Examples of suitable surfactants are given below. Dispersions can also be prepared, for example, in glycerol, liquid polyethylene glycols and mixtures of the same in oils.
The pharmaceutical compositions for use in the methods of the present invention can further comprise one or more additives in addition to any carrier or diluent (such as lactose or mannitol) that is present in the formulation. The one or more additives can comprise or consist of one or more surfactants. Surfactants typically have one or more long aliphatic chains such as fatty acids which enables them to insert directly into the lipid structures of cells to enhance drug penetration and absorption. An empirical parameter commonly used to characterize the relative hydrophilicity and hydrophobicity of surfactants is the hydrophilic-lipophilic balance (“HLB” value). Surfactants with lower HLB values are more hydrophobic, and have greater solubility in oils, while surfactants with higher HLB values are more hydrophilic, and have greater solubility in aqueous solutions. Thus, hydrophilic surfactants are generally considered to be those compounds having an HLB value greater than about 10, and hydrophobic surfactants are generally those having an HLB value less than about 10. However, these HLB values are merely a guide since for many surfactants, the HLB values can differ by as much as about 8 HLB units, depending upon the empirical method chosen to determine the HLB value.
All percentages and ratios used herein, unless otherwise indicated, are by weight. Other features and advantages of the present invention are apparent from the different examples. The provided examples illustrate different components and methodology useful in practicing the present invention. The examples do not limit the claimed invention. Based on the present disclosure the skilled artisan can identify and employ other components and methodology useful for practicing the present invention.
Kits Comprising the NRTI
In aspects, a kit for an NRTI is provided. In embodiments, the kit comprises the NRTI and reagents.
In embodiments, components of the kit are suitable for delivery (e.g., systemic administration) to a subject.
The present invention also provides packaging and kits comprising pharmaceutical compositions for use in the methods of the present invention. The kit can comprise one or more containers selected from the group consisting of a bottle, a vial, an ampoule, a blister pack, and a syringe. The kit can further include one or more of instructions for use in treating and/or preventing a disease, condition or disorder of the present invention (e.g., a joint diseases such as osteoarthritis), one or more syringes, one or more applicators, or a sterile solution suitable for reconstituting a pharmaceutical composition of the present invention.
General Definitions
Unless specifically defined otherwise, all technical and scientific terms used herein shall be taken to have the same meaning as commonly understood by one of ordinary skill in the art (e.g., in cell culture, molecular genetics, and biochemistry).
As used herein, the term “about” in the context of a numerical value or range means ±10% of the numerical value or range recited or claimed, unless the context requires a more limited range.
In the descriptions above and in the claims, phrases such as “at least one of” or “one or more of” may occur followed by a conjunctive list of elements or features. The term “and/or” may also occur in a list of two or more elements or features. Unless otherwise implicitly or explicitly contradicted by the context in which it is used, such a phrase is intended to mean any of the listed elements or features individually or any of the recited elements or features in combination with any of the other recited elements or features. For example, the phrases “at least one of A and B;” “one or more of A and B;” and “A and/or B” are each intended to mean “A alone, B alone, or A and B together.” A similar interpretation is also intended for lists including three or more items. For example, the phrases “at least one of A, B, and C;” “one or more of A, B, and C;” and “A, B, and/or C” are each intended to mean “A alone, B alone, C alone, A and B together, A and C together, B and C together, or A and B and C together.” In addition, use of the term “based on,” above and in the claims is intended to mean, “based at least in part on,” such that an unrecited feature or element is also permissible
It is understood that where a parameter range is provided, all integers within that range, and tenths thereof, are also provided by the invention. For example, “0.2-5 mg” is a disclosure of 0.2 mg, 0.3 mg, 0.4 mg, 0.5 mg, 0.6 mg etc. up to and including 5.0 mg.
A small molecule is a compound that is less than 2000 daltons in mass. The molecular mass of the small molecule is preferably less than 1000 daltons, more preferably less than 600 daltons, e.g., the compound is less than 500 daltons, 400 daltons, 300 daltons, 200 daltons, or 100 daltons.
As used herein, an “isolated” or “purified” nucleic acid molecule, polynucleotide, polypeptide, or protein, is substantially free of other cellular material, or culture medium when produced by recombinant techniques, or chemical precursors or other chemicals when chemically synthesized. Purified compounds are at least 60% by weight (dry weight) the compound of interest. Preferably, the preparation is at least 75%, more preferably at least 90%, and most preferably at least 99%, by weight the compound of interest. For example, a purified compound is one that is at least 90%, 91%, 92%, 93%, 94%, 95%, 98%, 99%, or 100% (w/w) of the desired compound by weight. Purity is measured by any appropriate standard method, for example, by column chromatography, thin layer chromatography, or high-performance liquid chromatography (HPLC) analysis. A purified or isolated nucleoside, nucleoside analog, e.g., NRTI, polynucleotide (ribonucleic acid (RNA) or deoxyribonucleic acid (DNA)) of nucleotides or nucleosides that flank it in its naturally occurring states. A purified or isolated polypeptide is free of the amino acid sequences that flank it in its naturally-occurring state. Purified also defines a degree of sterility that is safe for administration to a human subject, e.g., lacking infectious or toxic agents.
Similarly, by “substantially pure” is meant a nucleotide or polypeptide that has been separated from the components that naturally accompany it. Typically, the nucleotides and polypeptides are substantially pure when they are at least 60%, 70%, 80%, 90%, 95%, or even 99%, by weight, free from the proteins and naturally-occurring organic molecules with they are naturally associated.
The transitional term “comprising,” which is synonymous with “including,” “containing,” or “characterized by,” is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. By contrast, the transitional phrase “consisting of” excludes any element, step, or ingredient not specified in the claim. The transitional phrase “consisting essentially of” limits the scope of a claim to the specified materials or steps “and those that do not materially affect the basic and novel characteristic(s)” of the claimed invention.
The terms “subject,” “patient,” “individual,” and the like as used herein are not intended to be limiting and can be generally interchanged. That is, an individual described as a “patient” does not necessarily have a given disease, but may be merely seeking medical advice.
The term “subject” as used herein includes a human or animal diagnosed with an osteoarthritic disorder.
As used herein, the singular forms “a,” “an,” and “the” include the plural reference unless the context clearly dictates otherwise. Thus, for example, a reference to “a disease,” “a disease state”, or “a nucleic acid” is a reference to one or more such embodiments, and includes equivalents thereof known to those skilled in the art and so forth.
As used herein, “treating” encompasses, e.g., inhibition, regression, or stasis of the progression of a disorder. Treating also encompasses the prevention or amelioration of any symptom or symptoms of the disorder. As used herein, “inhibition” of disease progression or a disease complication in a subject means preventing or reducing the disease progression and/or disease complication in the subject.
As used herein, a “symptom” associated with a disorder includes any clinical or laboratory manifestation associated with the disorder, and is not limited to what the subject can feel or observe.
As used herein, “effective” when referring to an amount of a therapeutic compound refers to the quantity of the compound that is sufficient to yield a desired therapeutic response without undue adverse side effects (such as toxicity, irritation, or allergic response) commensurate with a reasonable benefit/risk ratio when used in the manner of this disclosure.
As used herein, “pharmaceutically acceptable” carrier or excipient refers to a carrier or excipient that is suitable for use with humans and/or animals without undue adverse side effects (such as toxicity, irritation, and allergic response) commensurate with a reasonable benefit/risk ratio. It can be, e.g., a pharmaceutically acceptable solvent, suspending agent or vehicle, for delivering the instant compounds to the subject.
Examples are provided below to facilitate a more complete understanding of the invention. The following examples illustrate the exemplary modes of making and practicing the invention. However, the scope of the invention is not limited to specific embodiments disclosed in these Examples, which are for purposes of illustration only, since alternative methods can be utilized to obtain similar results.
“Percentage of sequence identity” is determined by comparing two optimally aligned sequences over a comparison window, wherein the portion of the polynucleotide or polypeptide sequence in the comparison window may comprise additions or deletions (i.e., gaps) as compared to the reference sequence (which does not comprise additions or deletions) for optimal alignment of the two sequences. The percentage is calculated by determining the number of positions at which the identical nucleic acid base or amino acid residue occurs in both sequences to yield the number of matched positions, dividing the number of matched positions by the total number of positions in the window of comparison and multiplying the result by 100 to yield the percentage of sequence identity.
The term “identical” or percent “identity,” in the context of two or more nucleic acids or polypeptide sequences, refer to two or more sequences or subsequences that are the same or have a specified percentage of amino acid residues or nucleotides that are the same (e.g., 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or more identity over a specified region, e.g., of an entire polypeptide sequence or an individual domain thereof), when compared and aligned for maximum correspondence over a comparison window, or designated region as measured using a sequence comparison algorithm or by manual alignment and visual inspection. Such sequences that are at least about 80% identical are said to be “substantially identical.” In some embodiments, two sequences are 100% identical. In certain embodiments, two sequences are 100% identical over the entire length of one of the sequences (e.g., the shorter of the two sequences where the sequences have different lengths). In various embodiments, identity may refer to the complement of a test sequence. In some embodiments, the identity exists over a region that is at least about 10 to about 100, about 20 to about 75, about 30 to about 50 amino acids or nucleotides in length. In certain embodiments, the identity exists over a region that is at least about 50 amino acids in length, or more preferably over a region that is 100 to 500, 100 to 200, 150 to 200, 175 to 200, 175 to 225, 175 to 250, 200 to 225, 200 to 250 or more amino acids in length.
For sequence comparison, typically one sequence acts as a reference sequence, to which test sequences are compared. In various embodiments, when using a sequence comparison algorithm, test and reference sequences are entered into a computer, subsequence coordinates are designated, if necessary, and sequence algorithm program parameters are designated. Preferably, default program parameters can be used, or alternative parameters can be designated. The sequence comparison algorithm then calculates the percent sequence identities for the test sequences relative to the reference sequence, based on the program parameters.
A the “comparison window” refers to a segment of any one of the number of contiguous positions (e.g., least about 10 to about 100, about 20 to about 75, about 30 to about 50, 100 to 500, 100 to 200, 150 to 200, 175 to 200, 175 to 225, 175 to 250, 200 to 225, 200 to 250) in which a sequence may be compared to a reference sequence of the same number of contiguous positions after the two sequences are optimally aligned. In various embodiments, a comparison window is the entire length of one or both of two aligned sequences. In some embodiments, two sequences being compared comprise different lengths, and the comparison window is the entire length of the longer or the shorter of the two sequences. Methods of alignment of sequences for comparison are well-known in the art. Optimal alignment of sequences for comparison can be conducted, e.g., by the local homology algorithm of Smith & Waterman, Adv. Appl. Math. 2:482 (1981), by the homology alignment algorithm of Needleman & Wunsch, J. Mol. Biol. 48:443 (1970), by the search for similarity method of Pearson & Lipman, Proc. Nat'l. Acad. Sci. USA 85:2444 (1988), by computerized implementations of these algorithms (GAP, BESTFIT, FASTA, and TFASTA in the Wisconsin Genetics Software Package, Genetics Computer Group, 575 Science Dr., Madison, Wis.), or by manual alignment and visual inspection (see, e.g., Current Protocols in Molecular Biology (Ausubel et al., eds. 1995 supplement)).
In various embodiments, an algorithm that is suitable for determining percent sequence identity and sequence similarity are the BLAST and BLAST 2.0 algorithms, which are described in Altschul et al., Nuc. Acids Res. 25:3389-3402 (1977) and Altschul et al., J. Mol. Biol. 215:403-410 (1990), respectively. BLAST and BLAST 2.0 may be used, with the parameters described herein, to determine percent sequence identity for nucleic acids and proteins. Software for performing BLAST analyses is publicly available through the National Center for Biotechnology Information, as known in the art. This algorithm involves first identifying high scoring sequence pairs (HSPs) by identifying short words of length W in the query sequence, which either match or satisfy some positive-valued threshold score T when aligned with a word of the same length in a database sequence. T is referred to as the neighborhood word score threshold (Altschul et al., supra). These initial neighborhood word hits act as seeds for initiating searches to find longer HSPs containing them. The word hits are extended in both directions along each sequence for as far as the cumulative alignment score can be increased. Cumulative scores are calculated using, for nucleotide sequences, the parameters M (reward score for a pair of matching residues; always >0) and N (penalty score for mismatching residues; always <0). For amino acid sequences, a scoring matrix is used to calculate the cumulative score. Extension of the word hits in each direction are halted when: the cumulative alignment score falls off by the quantity X from its maximum achieved value; the cumulative score goes to zero or below, due to the accumulation of one or more negative-scoring residue alignments; or the end of either sequence is reached. The BLAST algorithm parameters W, T, and X determine the sensitivity and speed of the alignment. The BLASTN program (for nucleotide sequences) uses as defaults a wordlength (W) of 11, an expectation (E) of 10, M=5, N=−4 and a comparison of both strands. For amino acid sequences, the BLASTP program uses as defaults a wordlength of 3, and expectation (E) of 10, and the BLOSUM62 scoring matrix (see Henikoff & Henikoff, Proc. Natl. Acad. Sci. USA 89:10915 (1989)) alignments (B) of 50, expectation (E) of 10, M=5, N=−4, and a comparison of both strands.
EXAMPLES
The following examples illustrate certain specific embodiments of the invention and are not meant to limit the scope of the invention.
Embodiments herein are further illustrated by the following examples and detailed protocols. However, the examples are merely intended to illustrate embodiments and are not to be construed to limit the scope herein. The contents of all references and published patents and patent applications cited throughout this application are hereby incorporated by reference.
Compared to other methods, an illustrative non-limiting method in the Example that follows uses three commercially available mediums to generate beige adipocytes, which are largely serum/xeno free, which resulted in more consistent results. These beige adipocytes were functionally similar to brown adipocytes, but are developmentally distinct. In embodiments, serum characteristics can change from lot to lot, and mediums that are highly quality controlled are preferably used.
Example 1: Activation of L1 in OA and its Dependency on miR-365
To determine whether L1 levels were elevated in OA joint, RNA was extracted from an OA lesion and non-lesion area (
L1 levels were significantly up-regulated in the OA lesion area than a non-lesion area in the majority of OA patients (
To test this association, mouse primary chondrocytes were transfected with miR-365 mimic. MiR-365 significantly induced L1 (
To determine whether L1 activation also depends on miR-365 in vivo, mice were generated harboring the miR-365-Flox transgene in an intergenic region on chromosome 4 (Yang, K., et al. Connect Tissue Res 58, 103-115 (2017)). Crossing of miR-356-Flox mice with Col2a1 Cre mice generated transgenic mice (miR-365 Tg) in which miR-365 transgene was specifically expressed in cartilage (
To determine whether L1 activation was also associated with injury induced PTOA, joint injury was generated by performing destabilizing medial meniscus (DMM) surgery in two genetic strains of mice (129s6/SvEv and C57BL/6) that have different OA development periods (
To determine the effects of aging process on L1 levels, DMM surgery was performed on C57BL/6 mice and let them age for additional five months (
Example 2: Mechanisms of miR-Dependent L1 Activation
MiR365 could be induced by mechanical stress and inflammatory cytokines (Yang, X., et al. Int J Mol Sci 17, 436 (2016), and Guan, Y. J., et al. FASEB journal 25, 4457-4466 (2011)), however, it was not known how it could activate L1. It was hypothesized that miR-365 activated L1 by targeting L1 inhibitors in the host defense pathways in a post-transcription manner. Through bioinformatics analysis of 40 L1 inhibitors based on published literature (Goodier, J. L. Mob DNA 7, 16 (2016)), five L1 inhibitors were identified that harbored potential miR-365 binding sites in its 3′ UTR of mRNA in both human and mouse (
These targets were further screened in three ways (
miR-365 activated L1 through inhibiting Dicer and Sqstm1. While transfection of miR-365 mimic stimulated L1 at both RNA and protein levels (
Example 3: Repressing L1 Inhibits Early Onset of OA
L1 can be repressed by nucleoside reverse transcriptase inhibitors (NRTIs) (Dai, L., Huang, Q. & Boeke, J. D. BMC Biochem 12, 18 (2011), Patnala, R., et al. Breast Cancer Res Treat 143, 239-253 (2014), and Jones, R. B., et al. PLoS One 3, e1547 (2008)). To determine whether repressing L1 by NRTI is sufficient to inhibit OA gene expression, chondrocytes were treated with Lamivudine (3TC) in a series of concentrations (
The gene expression of Prkdc at RNA level in mouse articular cartilage treated with 3TC for 4 months was assessed by RT-qPCR. Line-1-ORF2, Alu, IL-6, Col10a1, Adamts5 and miR-365 expression was significantly suppressed in miR-365 Tg mice treated with 3TC comparing with elevated Line-1 expression in Saline treated miR-365 Tg mice. 3TC treatment significantly up-regulated Sqstm1 and Zac3hav1 expression in miR-365 Tg mice. Student t-test and one-way ANOVA test (x-ac) were used for statistics. n≥4. *p≤0.05, **p≤0.01 relative to appropriate control groups respectively.
Also, the gene expression of Dicer at RNA level in mouse articular cartilage treated with 3TC for 4 months was assessed by RT-qPCR. Line-1-ORF2, Alu, IL-6, Col10a1, Adamts5 and miR-365 expression was significantly suppressed in miR-365 Tg mice treated with 3TC comparing with elevated Line-1 expression in Saline treated miR-365 Tg mice. 3TC treatment significantly up-regulated Sqstm1 and Zac3hav1 expression in miR-365 Tg mice. Student t-test and one-way ANOVA test (x-ac) were used for statistics. n≥4. *p≤0.05, **p≤0.01 relative to appropriate control groups respectively.
The gene expression of Sqstm1 at RNA level in mouse articular cartilage treated with 3TC for 4 months was assessed by RT-qPCR. Line-1-ORF2, Alu, IL-6, Col10a1, Adamts5 and miR-365 expression was significantly suppressed in miR-365 Tg mice treated with 3TC comparing with elevated Line-1 expression in Saline treated miR-365 Tg mice. 3TC treatment significantly up-regulated Sqstm1 and Zac3hav1 expression in miR-365 Tg mice. Student t-test and one-way ANOVA test (x-ac) were used for statistics. n≥4. *p≤0.05, **p≤0.01 relative to appropriate control groups respectively.
The gene expression of Zc3hav1 at RNA level in mouse articular cartilage treated with 3TC for 4 months was assessed by RT-qPCR. Line-1-ORF2, Alu, IL-6, Col10a1, Adamts5 and miR-365 expression was significantly suppressed in miR-365 Tg mice treated with 3TC comparing with elevated Line-1 expression in Saline treated miR-365 Tg mice. 3TC treatment significantly up-regulated Sqstm1 and Zac3hav1 expression in miR-365 Tg mice. Student t-test and one-way ANOVA test (x-ac) were used for statistics. n≥4. *p≤0.05, **p≤0.01 relative to appropriate control groups respectively.
To determine whether 3TC was sufficient to suppress OA pathogenesis in vivo, miR-365 Tg mice were treated with oral administration of 3TC for four months starting from 2-months old (
To determine whether 3TC treatment abolished the miR-365 inhibition of L1 inhibitors, the mRNA levels of Dicer, Prkdc, Sqstm1, and Zc3hav1 were quantified in miR-365 Tg mice after 3TC treatment for four months. While the expression levels of these inhibitors were inhibited in the 6-months old miR-365 Tg mice (
NRTIs may decrease bone mineral density (BMD) in human HIV patients (Hoy, J. F., et al. J Bone Miner Res 32, 1945-1955 (2017)). OA pathogenesis can be associated with increased BMD in subchondral bone (Hochberg, M. C., Osteoarthritis and cartilage/OARS, Osteoarthritis Research Society 12 Suppl A, S45-48 (2004) and Hardcastle, S. A., et al., Bonekey Rep 4, 624 (2015)). To determine whether 3TC affected BMD in miR-365 Tg mice, microCT was performed to quantify subchondral bone properties. Although tibial subchondral BV/TV was increased in miR-365 Tg mice (
Example 4: NRTIs Inhibit OA Pathogenesis in Mice
To determine whether other NRTIs also inhibited OA gene expression, mouse chondrocytes were treated with Emtricitabine (FTC) in a series of concentrations (
To determine whether NRTIs inhibited PTOA, DMM surgery was performed to induce PTOA in 129s6/SvEv mice (
Whether NRTIs inhibited subchondral bone mineral density in PTOA mice was also determined. Local bone sclerosis could be seen under the cartilage OA lesion in DMM mice (
The de-repression of endogenous L1 in cartilage lesions, as disclosed herein, is a mechanism responsible for initiation and progression of OA, a common human degenerative joint disease (Berenbaum, F. Osteoarthritis and cartilage/OARS, Osteoarthritis Research Society 21, 16-21 (2013), and Helmick, C. G., et al. Arthritis and rheumatism 58, 15-25 (2008), Lawrence, R. C., et al. Arthritis and rheumatism 58, 26-35 (2008), Michaud, C. M., et al. Popul Health Metr 4, 11 (2006), Andrianakos, A. A., et al. The Journal of rheumatology 33, 2507-2513 (2006), and D'Ambrosia, R. D. Orthopedics 28, s201-205 (2005)). The data suggested that it is at least a two-step pathogenic process. L1, the only cell autonomous retrotransposon, could be activated initially by mechanical and/or inflammation stress signals in tissue wound due to joint injury (
The efficacy of NRTIs for the treatment of joint degeneration has been demonstrated at cell and tissue levels, in vitro and in vivo, for OA and PTOA, in mice and human, and by basic and clinical research approaches (
Activation of L1 in senescent cells during aging was a recent discovery and its mechanisms to cause aging associated disease were largely unknown Belancio, V. P., et al. Nucleic acids research 38, 3909-3922 (2010), Erichsen, L., et al. Saudi J Biol Sci 25, 1220-1226 (2018), Shi, X., Seluanov, A. & Gorbunova, V. Molecular and cellular biology 27, 1264-1270 (2007), Cho, Y. H., et al PloS one 10, e0133909 (2015), St Laurent, G., 3rd, Hammell, N. & McCaffrey, Mech Ageing Dev 131, 299-305 (2010), Carlini, F., et al. PloS one 5, e14221 (2010), Ogino, S., et al. J Natl Cancer Inst 100, 1734-1738 (2008), and Ogino, S., et al. Cancer Epidemiol Biomarkers Prev 18, 2513-2521 (2009)). Herein, it was shown that miR-365 could be an activator of L1 in response to mechanical and inflammatory stress signals during tissue injury in vivo (
Herein, miR-365 induced L1 by targeting multiple cellular surveillance molecules responsible for repressing L1 in cell defense pathways post-transcriptionally (
Thus, this study has revealed a molecular mechanism by which L1 retrotransposons are activated by stress signals, amplified during aging, and resulting in tissue degeneration. OA is the first degenerative disease associated with L1 activation.
The following materials and methods were used to generate data described herein.
Animals
The use of animals is approved by Lifespan IACUC animal studies committee and all animal studies were performed in accordance with institutional guidelines. To over-express miR-365 in cartilage tissues, C57BL/6 background miR-365fl+/− transgenic mice were crossed with miR-365 fl−/−; Col2a1-cre+/− (Cre-only) mice to generate miR-365 fl+/−; Col2a1-cre+/− mice (miR-365 Tg)1. Cre-only and miR-365 Tg mice were used in the studies regardless of their sexes as OA is not a sex-specific disease.
12956/SvEv strain male mice were purchased from Taconic (https://www.taconic.com/mouse-model/129s6) at their age of 7-week-old. At least 3-day (72-hrs) acclimation period must be given to mice before any further procedures occurred to them. All 12956/SvEv strain mice throughout the studies were male.
All strains of mice were housed with ad libitum access to food and water unless otherwise stated.
Genotyping
Genomic DNA was extracted from mouse toes or tails within 7 days after birth and conventional PCR was performed using Hot start Taq polymerase (New England BioLabs, Cat. M049S/L) using primers designed specific to miR-365 insertion or Col2a1-Cre constructs (Table 1, below) (Berenbaum, F. Osteoarthritis and cartilage/OARS, Osteoarthritis Research Society 21, 16-21 (2013)).
Mouse Model of Destabilization of Medial Meniscus (DMM)
129S6/SvEv male mice were chosen for experimental subjects at their age of 8-week-old. To create mouse injury/trauma induced OA model, medial meniscus ligament was transected using a previously described method (Lohmander, L. S., et al. Am J Sports Med 35, 1756-1769 (2007)). Briefly, 8-week-old male mice were anesthetized using either intraperitoneal (IP) injection of Ketamine/Dexmedetomidine or isoflurane to carry out medial parapatellar arthrotomy. Transection was made with a stab knife (Sharpoint™, Cat. 72-1551). At Weeks 12, mice were euthanized and dissected for histological examination as well as cartilage RNA extraction. 12 mice were used for each group/time point.
Human Specimens
Cartilages were prospectively gathered from consenting individuals who had been diagnosed with OA and underwent total knee replacement. All the procedures were prior approved by IRB. For the sake of patients' identity protection, all the information was confidential except for those relevant to experiments, such as information of gender and age. Samples were harvested immediately after surgeries. Pictures of specimens were taken for recording purpose (
Femur Explant Organ Culture
Femurs were obtained from 21-day-old WT C57BL/6 mice. Femurs with intact articular surface and periosteum was sterilely dissected under microscope. Upon harvesting, femurs were rinsed with HBSS (Gibco®, Grand Island, N.Y. 14072 USA) and then submerged into DMEM (Gibco, Grand Island, N.Y. 14072 USA) medium supplemented with 10% fetal bovine serum (FBS, Gibco®, Grand Island, N.Y. 14072 USA) in 12-well culture dishes. The first-generation cytidine analogue/NRTI-3TC or newest-generation cytidine analogue/NRTI-FTC was added into the medium with desired concentrations. After a total of 48 hrs incubation at 37° C. in an atmosphere of 5% CO2, femurs were rinsed with HBSS and articular cartilage was peeled off using surgical scalpels under dissecting microscope for RNA extraction.
Histology, Immunohistochemistry (IHC), and Immunofluorescence
Human cartilage tissues were fixed in 4% Paraformaldehyde (PFA) for 24 hrs at 4° C., followed by 30% Diethyl pyrocarbonate (DEPC)-sucrose (Sigma, Cat. 50289-500G, St. Louis, Mo. 63103 USA) at 4° C. until the specimens were sunken to the bottom of the containers. Tissues were embedded in optimal cutting temperature compound (O.C.T., SAKURA FINETEK USA INC, Tissue-Tek® O.C.T. Compound, Cat. 4583). A cryo-section microtome (Model: CM3050, Leica, Germany) was used to cut 6-μm-thick sections. The sections were stained by H&E staining to assess morphology. Mouse tissues were fixed in 10% formalin for 24-48 hrs depending on tissue size, followed by de-calcification process using DEPC de-calcification reagents (Ethylenediaminetetraacetic acid, Sigma, Cat. EDS-1KG, St. Louis, Mo. 63103 USA) at room temperature for 10-14 days. After de-calcification, tissues were dehydrated in ethanol before embedded in paraffin with routine procedures. A microtome (Model: FINESSE ME, Thermo Shandon, UK) was used to cut 6-μm-thick sections. For every 80 μm interval, 5 sister sections were harvested to make a total of 13-16 slices from one knee of a fully-grown mouse. Number of slides form one knee may vary due to varying sizes of the specimens. Slides were then de-paraffinized and stained GAG with Alcian blue (Sigma, Cat. A3157-10G) or Safranin O (Sigma, Cat. 58884-25G, St. Louis, Mo. 63103 USA). Morphology is assessed by H&E staining. For IHC, paraffin sections were processed with routine procedures instructed by Histostain® Plus 3rd Gen IHC Detection Kit (Life Technologies, Cat. 859673, Frederick, Md. 21704 USA). Rabbit or mouse antibodies specifically against antigens of interest were used, followed by incubation of HRP-conjugated secondary antibodies against rabbit or mouse IgG (provided by the kit). Primary and secondary antibodies are listed in Table 3 below. Signals are then visualized by a DAB-Plus Substrate Kit (Life Technologies, Cat. 002020, Frederick, Md. 21704 USA).
Safranin O Staining
Paraffin sections were de-paraffinized in 2 changes of xylene, 10 mins each, followed by re-hydration in 2 changes of 100% alcohol, 5 mins each; 2 changes of 95% alcohol, 5 mins each; 70% alcohol for 5 mins. Sections were then rinsed in running tap water for 2 mins before stained with 0.4% fast green solution (Sigma, Cat. F-7258, St. Louis, Mo. 63103 USA) for 2 mins however the latter timing must be empirically controlled to assure desired coloration. Stained sections were then quickly rinsed with 1% acetic acid solution (Sigma, Cat. 695092-500ML-GL, St. Louis, Mo. 63103 USA) for no more than 10-15 sec. 0.1% Safranin O Solution was used for staining proteoglycan however the actual timing must be carefully determined based on actual coloring condition, for maximally 10 mins. After Safranin O staining, sections were submerged in 2 changes of 95% alcohol, 2 mins each, 2 changes of 100% alcohol, 2 mins each for de-hydration. Lastly, sections were cleared in 2 changes of xylene, 2 mins each, and mounted using resinous mounting medium (ACRYMOUNT™, Cat. SL80-4, McKinney, Tex. 75069 USA).
OARSI Scoring
To histologically evaluate OA severity, we quantified Safranin O stained knee sections according to OARSI semi-quantitative system as previously described3. Detailed scoring standards are summarized in Table 4 below:
Hematoxylin and Eosin (H&E) Staining
Paraffin sections were de-paraffinized in 2 changes of xylene, 10 mins each, followed by re-hydration in 2 changes of 100% alcohol, 5 mins each; 2 changes of 95% alcohol, 5 mins each; 70% alcohol for 5 mins. Sections were then rinsed in running tap water for 2 mins before stained in Mayer's Hematoxylin solution (NovaUltra™ H&E Stain Kit, IHCWORLD, Cat. IW-3100) for 2 mins however the latter timing must be empirically controlled to assure desired coloration. Stained sections were then rinsed in running tap water for 5 mins before dipped into 95% alcohol for 10 times or 30″ based on performer's preference. Eosin Solution (NovaUltra™ H&E Stain Kit, IHCWORLD, Cat. IW-3100) was used for counterstaining however the actual timing must be carefully determined based on actual coloring condition. After counterstaining, sections were dipped in 95% alcohol for 2 times before transferred through 2 changes of 100% alcohol, 5 mins each for de-hydration. Lastly, sections are cleared in 2 changes of xylene, 5 mins each, and mounted with resinous mounting medium.
For frozen sections, procedures were similar with the exception between Eosin counterstaining and 95% alcohol dipping steps. Instead, during these two steps, frozen sections must be air dried for 30 mins at room temperature and fixed in 10% formalin for 10 mins. Then the sections were taken out for another 30 mins air dry at room temperature before rinsed in water.
Homogenization
A PowerGen 125 (Fisher Scientific, Cat. 03.349248) was used to homogenize samples for RNA extraction. A cycle of 45″ homogenization at speed of 5, followed by a cool down step of 15″ was repeated for 5 cycles before switching to a finer drill for the same cycles. Drills/PowerGen Generator (Fisher Scientific, Cat. 14-261-15) were rinsed in DEPC-water followed by 100% ethanol rinse between different specimens to avoid cross contamination. All procedures took place on ice to avoid RNA degradation due to heat.
Primary Growth Plate/Articular Chondrocytes (PCs) Culture
Rib cages were sterilely isolated from neonatal mice (within 7-day-old) of desired genotypes and rinsed with HBSS for five times. To remove unspecific tissues, rib cages were digested in Collagenase D (3 μg/mL, Roche, Cat. 11088882001, Mannheim, Germany) for 2-4 hrs at 37° C. and rinsed with HBSS (Gibco®, Grand Island, N.Y. 14072 USA) for five times to remove detached unspecific tissues. To detach chondrocytes from rib cages, the samples underwent secondary digestion in Collagenase D (3 μg/mL) for at least 4 hrs at 37° C. with constant agitation (200 rpm). Detached chondrocytes were pelleted to remove excessive Collagenase D and resuspended in complete medium of DMEM (Gibco®, Grand Island, N.Y. 14072 USA) which contains 10% FBS, 100 U/mL penicillin and 100 μg/mL streptomycin (Gibco®, Grand Island, N.Y. 14072 USA). Growth plate PCs were grown at 37° C. in an atmosphere of 5% CO2. The media was changed on the following day to remove remaining Collagenase D and every 3 days thereafter.
Similarly, articular cartilages were sterilely isolated under dissection microscope from neonatal mice (within 7-day-old) of desired genotypes and rinsed with HBSS for five times. In brief, the skins of hindlimbs were removed and transections on Ilia and muscles around hip joints were made to detach hindlimbs from torsi, then transferred to a petri dish. Under a dissection microscope placed in a cell culture hood, soft tissues were cleared while knee and hip joints were exposed. Femur heads could be easily peeled off whilst a fine cut of epiphyses based on vascularization were made to isolate articular cartilage from secondary ossification center. Beyond that, isolated tissues were minced into finer fragments and then put together before undergoing HBSS rinse and subsequent Collagenase D digestion. To remove unspecific tissues, articular cartilages were minced and digested in Collagenase D (3 μg/mL) for 2 hrs at 37° C. and rinsed with HBSS for five times to remove detached unspecific tissues. To detach chondrocytes from cartilage matrix, the samples underwent secondary digestion in Collagenase D (3 μg/mL) for at least 4 hrs at 37° C. with constant agitation (200 rpm). Detached chondrocytes were pelleted to remove excessive Collagenase D and resuspended in complete medium of DMEM which contains 10% FBS, 100 U/mL penicillin and 100 μg/mL streptomycin. Articular PCs were grown at 37° C. in an atmosphere of 5% CO2. The media was changed on the following day to remove remaining Collagenase D and every 3 days thereafter.
Transient Transfection
Cells were seeded onto desired size plates to reach 70-90% confluence and transfected with miR-365 mimic or miRNA mimic negative control or miR-365 inhibitor or inhibitor negative control (Dharmacon®, Lafayette, Colo., USA). Lipofectamine 3000 (Invitrogen®, Waltham, Mass., USA) was used as transfection reagents. Medium is changed 24 hrs after transfection. 48 hrs post transfection, cells were lysated in either QIAzol for RNA purification and real-time PCR analysis or ice-cold lysis buffer containing protease inhibitor and phosphatase inhibitor for western blot analysis. MiR-365 mimic, miRNA mimic negative control, miR-365 inhibitor and inhibitor negative control were typically used at a final concentration of 25 nM unless otherwise stated.
Quantitative Real-Time PCR (qPCR)
Both miRNA and mRNA were extracted using miRNeasy Mini Kit (Qiagen®, Germantown, Md., USA) and reversely transcribed using miScriptIIRT Kit (Qiagen®, Germantown, Md., USA) according to manufacturer's instruction. qPCR was performed using SYBR Green PCR master mix (Qiagen®, Germantown, Md., USA) on a Bio-Rad CFX96 real-time PCR detection system (Bio-Rad®, Hercules, Calif., USA). Amplification conditions are as follows: 95° C. for 10 min, 40 cycles of 95° C. for 10″, 55° C. for 30″, and 72° C. for 30″. Sense and antisense primers are listed in Table 2. 18S ribosomal or GAPDH RNA was used as an internal control gene to normalize the mRNAs level. The ubiquitously expressed snRNA U6 was used as an endogenous control for miRNAs level. Primers were synthesized by Integrated DNA Technologies (http://www.idtdna.com). The primers for miR-365 were purchased from Qiagen. Fold changes of mRNA and miRNAs were calculated by the 2{circumflex over ( )}(ΔΔCt) method and normalized to 18S/GAPDH or U6 snRNA, respectively.
Prediction of miR-365 Target Genes
Potential targets of miR-365-5p and miR-365-3p were identified using the TargetScan (http://www.targetscan.org/) and miRanda/mirSVR (http://34.236.212.39/microrna/home.do) target prediction algorithms.
Plasmid Construction
WT Aicda, Dicer1, Prkdc, Sqstm1 and Zc3hav1 3′UTRs bearing potential response elements (REs) serving as miR-365 seeding sites predicted by microrna.org were cloned from mouse genomic DNA (50 ng-250 ng) using primers designed to introduce ideal restriction enzyme cleavage sites according to the backbone plasmid pmirGLO construct (Promega, Madison, Wis., USA). Detailed thermal cycles are: 98° C. for 30 sec, 25-35 cycles of 98° C. for 10 sec, 55-60° C. for 30 sec, and 72° C. for 15 sec and final extension at 72° C. for 10 min before holding at 4° C. Designed primers are summarized in Table 1, above. PmeI and XhoI were enzymes used to cleave for sticky ends. After restriction enzymes cleavage, approximately 500 bp 3′UTR sequences were annealed into pmirGLO construct (1 pg-10 ng). REs were mutated according to QuikChange Lightning Multi Site-Directed Mutagenesis Kit's instruction (Agilent, Cat. 210513/210515, Santa Clare, Calif. 95051 USA).
Luciferase Assays
ATDC5 cells were cultured at 2.5×104 cells/well in 24-well plates. The cells were co-transfected with miR-365 mimic (25 nM) or miRNA mimic negative control (25 nM) and 500 ng of pmirGLO-Dicer1/Zap/Sqstm1/Prkdc/Aicda 3′-UTR WT or Mut plasmids. Transfection was performed using Lipofectamine 3000 (Invitrogen, Cat. L3000-008, Carlsbad, Calif. 92008 USA) reagent. The assays were performed in triplicate unless otherwise stated. 24 hrs after transfection, cells were collected, and luciferase activity was determined using the Dual-Luciferase reporter assay system (Promega, Madison, Wis., USA) with the GLOMAX 20/20 luminometer (Model: 2031_000, Turner BioSystems, Sunnyvale, Calif. USA). Briefly, cells were rinsed with PBS and incubated with Passive Lysis Buffer (provided by the kit) for 15 mins with constant agitation at room temperature. Lysates were scraped into 1.5 mL Eppendorf tubes. 20 μl of lysates were fixed with 50 μl Luciferase Assay Buffer II to measure Firefly luciferase luminescence. 50 μl Stop & Glo buffer was then added to measure Renilla luminescence. The luciferase activity was represented by the ratio of Firefly/Renilla measurements.
Western Blot (WB)
All pre-treated samples were washed with ice-cold PBS and lysated in RIPA buffer (M-PER, Pierce, Ill.) plus protease inhibitor phenylmethylsulfonyl fluoride [Halt™, Thermo Scientific, Protease Inhibitor Single-Use Cocktail (100×), Cat. 78430] for 30 min on ice with constant agitation. The lysates are centrifuged at 12,000 g for 15 min at 4° C. The supernatants were collected, and the protein concentrations were determined using Pierce™ BCA assay (Thermo Scientific, Cat. 23225). Samples were mixed with equal volume 2×Laemmli sample buffer (Bio-Rad, Cat. 161-0737) which contains 2-Mercaptoethanol (Bio-Rad, Cat. 161-0710) and heated for 5 min at 100° C. to denature. Equal amount of proteins for each sample were separated by 8-12% SDS polyacrylamide gel depending on protein size of interest and then transferred to nitro-cellulous membrane (Bio-Rad, Cat. 162-0112) for 70 min at 100 V. The membrane was blocked with 5% bovine serum albumin (BSA, Sigma, Cat. A7906-50G) in 0.1% Tris-Buffered Saline-Tween 20 (TBS-T, BBP, Cat. IBB-581X) for 1 hr at room temperature, followed by incubation with primary antibodies against proteins of interest (antibodies are listed in Table 3, provided above) at 4° C. overnight. On the following day, the membrane was rinsed with TBS-T for 10 min for a total of 5 times and incubated with anti-rabbit-Alexa Fluor 680 (Molecular Probes, Eugene, Oreg., USA) for 1 hr at room temperature followed by TBS-T rinse for 10 min for a total of 5 times. The blots were then scanned using an Odyssey fluorescence scanner (LI-COR Biosciences, Lincoln, Nebr., USA) and quantitatively analyzed by ImageJ (https://imagej.nih.gov/ij/index.html).
Statistical Analysis
Data represents mean values±SD (error bars). Statistical significance was calculated using student's t-test (unpaired) or one-way ANOVA test. A p-value≤0.05 was considered statistically significant. There is a minimum of n≥3 for all groups unless otherwise stated.
Other Embodiments
While the invention has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the scope of the following claims.
The patent and scientific literature referred to herein establishes the knowledge that is available to those with skill in the art. All United States patents and published or unpublished United States patent applications cited herein are incorporated by reference. All published foreign patents and patent applications cited herein are hereby incorporated by reference. Genbank and NCBI submissions indicated by accession number cited herein are hereby incorporated by reference. All other published references, documents, manuscripts and scientific literature cited herein are hereby incorporated by reference.
While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.