Assessment of combinatorial gene therapy for the treatment of Osteoarthritis

 描述(申请人提供)：骨关节炎(OA)是一种渐进性衰弱的疾病，涉及关节退行性变，导致关节僵硬和疼痛，活动能力下降，并增加医疗费用。尽管约有2700万美国人患有这种疾病，但没有任何药物治疗可以显著改变其进展。目前，患有骨性关节炎的患者只会被禁止服用疼痛治疗药物、物理治疗和改变生活方式，而在终末期疾病中，将建议进行关节置换手术。细胞因子和蛋白多糖的注射在临床和临床前试验中显示出一些前景，但由于这些化合物的快速降解和周转，需要重复注射才能获得任何长期的结果，这可能会导致不良事件的增加。开发新的骨性关节炎治疗方法的主要障碍包括难以确定动物模型进展的可量化终点，以及关节病理生理学中复杂的细胞自主和非细胞自主成分。为了克服这些障碍，我们的实验室开发了一种新的成像技术，将染色、位相对比光学和关节的MicroCT分析结合在一起，可以对小鼠软骨体积、表面积和骨赘形成进行可靠的量化。为了解决骨关节炎发生的复杂病因问题，我们的实验室已经确定分泌分子作为潜在的治疗靶点-蛋白多糖4(PRG4)和抗炎白细胞介素1受体拮抗剂(IL1Ra)。PRG4是软骨细胞外基质的主要成分，通过提供润滑剂来调节机械应力。炎症也被归因于疾病的进展，IL1ra已被证明通过抑制白细胞介素1(IL1)发挥抗炎作用。来自我们实验室和其他实验室的已发表的工作和初步数据都表明，每一个单独的都提供了一些防止OA进展的保护。我们假设，PRG4和IL1ra的联合治疗将通过解决软骨基质丢失和炎症，提供更好的保护，防止OA的发生和进展。我们的目的是通过在创伤后模型和年龄相关的OA发展模型中比较联合治疗和单一治疗的效果来测试这一点，因为导致疾病的个体因素的平衡在每种模型中都不同。先前的研究还表明，PRG4通过上调抑制性缺氧诱导因子3a(Hif3a)来抑制低氧反应，从而潜在地介导软骨保护；因此，在本项目的第三个目标中，我们将通过建立软骨特异性Hif3a转基因小鼠来进一步研究这一点，并确定它是否也受到保护，防止OA的发生和发展。这项研究对于为骨性关节炎患者建立新的治疗方案和治疗靶点具有重要意义。

 DESCRIPTION (provided by applicant): Osteoarthritis (OA) is a progressively debilitating condition involving joint degeneration that causes substantial joint stiffness and pain, decreased mobility, and increased health care costs. Despite approximately 27 million Americans being afflicted with this disease, there are no medical treatments that significantly alter its progressin. Currently, an individual suffering from OA will only be proscribed pain management medication, physical therapy and lifestyle modification, and in end---stage disease a joint replacement surgery will be advised. Injections of cytokines and proteoglycans have shown some promise in clinical and pre---clinical trials, yet due to the rapid degradation and turnover of these compounds, repeated injections are necessary to obtain any long---lasting results, potentially leading to an increase in adverse events. Major obstacles to the development of new treatments for OA have include both the difficulty of identifying quantifiable endpoints for progression in animal models, and the complex cell autonomous and non---cell autonomous components of the pathophysiology of the joint. To overcome these obstacles, our lab developed a novel imaging technique combining staining, phase--- contrast optics, and microCT analysis of the joint, which allows the robust quantification of murine cartilage volume, surface area, and osteophyte formation. To address the issue of the complex etiology of OA development, our lab has identified secreted molecules as potential therapeutic targets - Proteoglycan 4 (PRG4) and the anti---inflammatory Interleukin 1 Receptor antagonist (IL1Ra). PRG4 is a major component of the cartilage extracellular matrix and mediates mechanical stress by providing lubrication. Inflammation has also been attributed to disease progression, and IL1Ra has been proven to function as an anti---inflammatory through the inhibition of Interleukin 1 (IL1). Both published work and preliminary data from our lab and others shows that individually each provides some protection from OA progression. We hypothesize that combinatorial therapy with both PRG4 and IL1Ra will provide increased protection from OA development and progression through addressing cartilage matrix loss and inflammation. We aim to test this by comparing the effects of combinatorial therapy to mono---therapy in a post---traumatic model and in an age---related model of OA development, as the balance of individual factors contributing to disease is different in each. Prior studies have also shown that PRG4 potentially mediates cartilage protection through inhibition of the hypoxic response via upregulation of the inhibitory hypoxia inducible factor 3a (Hif3a); therefore in the third aim of this project we will investigate this futher through the generation and characterization of a cartilage---specific Hif3a transgenic mouse, and determine whether it is also protected from OA development and progression. This research is important for establishing new treatment options and therapeutic targets for patients with osteoarthritis.