Repressing Retrotransposon LINE-1: New Concepts for Osteoarthritis Treatment

抑制逆转录转座子 LINE-1：骨关节炎治疗的新概念

• 批准号: 10019329
• 负责人: QIAN CHEN
• 金额: $ 38.45万
• 依托单位: RHODE ISLAND HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-16 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10019329
• 关键词: Address; Aging; Animal Model; Antiviral Agents; Bioinformatics; Bone remodeling; Cartilage; Cell Aging; Cells; Chondrocytes; Chronic; Cytidine; Data; Degenerative polyarthritis; Development; Disease; Elderly; Elements; FDA approved; Gene Expression; Genes; Genetic Transcription; Goals; Health; Histology; Human; Inflammation; Injury; Intervention; Joints; Knowledge; Lamivudine; Lead; Length; Lesion; Mechanics; Medial meniscus structure; Mission; Molecular; Morphology; Movement; Mus; Nuclear; Nucleosides; Outcome; Pathogenesis; Pathway interactions; Patients; Pharmaceutical Preparations; Phase; Phenotype; Process; Proteins; Public Health; RNA; Repression; Research; Retrotransposon; Reverse Transcriptase Inhibitors; Role; Somatic Cell; Sterility; Telomere Shortening; Testing; Time; Tissue Sample; Tissues; Translating; Traumatic injury; United States National Institutes of Health; analog; articular cartilage; bone; cartilage degradation; clinical practice; disability; drug development; early onset; effective therapy; experimental study; gait examination; in vivo; in vivo Model; innovation; joint destruction; meniscus injury; microCT; mouse model; novel strategies; nucleoside inhibitor; overexpression; response; senescence

Abstract Osteoarthritis (OA) is a degenerative joint disease involving articular cartilage degradation, chronic inflammation, and bone remodeling. Although it is a leading cause of disability in the elderly, there is no FDA approved disease modifying osteoarthritis drugs (DMOADs) currently. The scientific challenge is the incomplete understanding of mechanisms triggering inflammation and degeneration in the joint during aging or after injury, which hampers the development of DMOADs that can target these processes. The scientific goal of this project is to determine whether retrotransposon Long Interspersed Nuclear Element-1 (LINE-1, or L1), which is repressed in normal somatic cells but de-repressed in senescent cells during aging or after traumatic injury, contribute to aging-associated or post-traumatic OA (PTOA). We found that L1 levels are significantly elevated in human OA cartilage lesions and in cartilage joint of both aging-associated OA and PTOA mouse models. The innovative hypothesis is that, during aging and/or injury-associated OA, the cellular content of L1 retrotransposons is 1) significantly increased in the joint and 2) responsible for stimulation of SASP and inflammation that lead to joint destruction. If so, OA pathogenesis can be inhibited by repressing L1 using FDA- approved anti-viral drug nucleoside reverse transcriptase inhibitors (NRTIs). This hypothesis will be tested through two aims in the R61 Phase. The first aim is to characterize aging and injury induced L1 de-repression in the Col2a1-CreERT2; miR-365 mice capable of inducing early onset-OA and/or PTOA. It will establish whether aging, injury, or both would result in de-repression of the L1 levels in mouse joint during OA. The second aim is to determine whether NRTIs inhibit OA pathogenesis by repressing L1 levels in OA animal models in vivo. NRTI nucleoside cytidine analogue Lamivudine will be tested for its ability of inhibiting OA/PTOA in CreERT2; miR-365 mice. It will establish the efficacy and the window of intervention for NRTI to modify cartilage degeneration, bone remodeling, SASP gene expression, and movement deficiency in OA animal models in vivo. If the hypothesis is unambiguously supported by the experiments in R61 Phase, it will be further explored, through a mechanistic aim in the R33 Phase, to determine the molecular pathways by which L1 activates OA pathogenesis in OA mouse models and human OA tissues. It will establish the molecular pathways of L1 de-repression induced OA marker genes and SASP expression at the cellular level. This project represents a new and distinct direction for the field because it addresses the role of retrotransposons in OA pathogenesis for the very first time. If successful, NRTIs, which are safe and readily available, can be re-purposed for OA treatment in human. It will not only change the concepts that drive the OA research field, but also greatly impact the clinical practice of how we treat OA patients.

摘要 骨关节炎（OA）是一种退行性关节疾病，涉及关节软骨退化、慢性关节炎和关节炎。 炎症和骨重塑虽然它是导致老年人残疾的主要原因，但没有FDA 目前已批准的疾病缓解骨关节炎药物（DMOAD）。科学上的挑战是 对老化过程中引发关节炎症和退化的机制不完全了解，或 这阻碍了可以针对这些过程的DMOAD的发展。科学目标 该项目的目的是确定逆转录转座子长散布核元件-1（LINE-1，或L1）， 其在正常体细胞中被抑制，但在衰老期间或创伤后在衰老细胞中去抑制 损伤，导致老化相关或创伤后OA（PTOA）。我们发现L1水平显著高于 在人OA软骨病变中以及在衰老相关OA和PTOA小鼠的软骨关节中升高 模型创新的假设是，在老化和/或损伤相关的OA，L1的细胞内容物， 逆转录转座子1）在关节中显著增加，2）负责刺激SASP， 导致关节破坏炎症。如果是这样的话，OA的发病机制可以通过使用FDA抑制L1来抑制。 批准的抗病毒药物核苷逆转录酶抑制剂（NRTI）。这一假设将得到检验 R61阶段的两个目标。第一个目的是表征衰老和损伤诱导的L1去阻遏 在能够诱导早发性OA和/或PTOA的Col 2a 1-CreERT 2; miR-365小鼠中。它将建立 老化、损伤或两者是否会导致OA期间小鼠关节中L1水平的去抑制。的 第二个目的是确定NRTI是否通过抑制OA动物中的L1水平来抑制OA发病机制 体内模型。NRTI核苷胞苷类似物拉米夫定将测试其抑制 CreERT 2; miR-365小鼠中的OA/PTOA。它将确定NRTI的疗效和干预窗口， 改变OA中的软骨退变、骨重建、SASP基因表达和运动缺陷 体内动物模型。如果R61阶段的实验明确支持这一假设， 通过R33阶段的机制目标进一步探索，以确定分子途径， 其中L1在OA小鼠模型和人OA组织中激活OA发病机制。它将建立 L1去阻遏的分子途径在细胞水平诱导OA标记基因和SASP表达。 该项目代表了该领域的一个新的和独特的方向，因为它涉及以下方面的作用： 逆转录转座子在OA发病机制中的作用。如果成功的话，NRTI，这是安全的，容易 可用，可以重新用于人类的OA治疗。它不仅会改变驱动OA的概念， 研究领域，而且也极大地影响了我们如何治疗OA患者的临床实践。