The Toll-like receptor pathway in Meniscal Injury and Osteoarthritis

候选人：卡拉·R·斯坎泽洛，医学博士，拉什大学医学中心(芝加哥)医学助理教授。她于2008年6月在特别外科医院完成了风湿病学的研究，最近被那里的医学系(风湿科)录用。她对炎症在骨关节炎(OA)发病机制中所起的作用特别感兴趣，作为风湿病研究员，她开始认真研究这一问题。在她担任研究员期间，她设计了一项研究项目，以确定OA患者滑膜细胞群和炎症介质的特征。由于之前发表的大多数关于骨性关节炎炎症的工作都集中在晚期疾病患者身上，她的项目旨在描述明确定义的早期疾病患者的炎症反应。这项工作已经产生了多份手稿(一份已出版，一份已接受，一份正在准备中)，来自该项目的观察导致了本申请中提出的假设。这一奖项将使斯坎泽洛博士获得在免疫学和软骨生物化学领域使用的特定实验室技术方面的进一步培训，以获得作为一名研究人员的完全独立。她致力于在基质生物化学和免疫学的交叉点上从事翻译研究，因为它适用于OA病理生理学，最终目标是在这种常见疾病的早期阶段开发新的治疗方法。环境：斯坎泽洛博士最近接受了一个终身教职的职位，以追求成为一名独立研究员的目标。这一职位使她能够获得实现本提案目标所需的资源。她将获得的必要资源包括教师专业知识和支持、合适的导师、优秀的临床和研究合作者、充足的实验室空间和设备，以及通过整形外科接触到合适的患者群体。她75%的时间致力于研究，不受过多的教学和行政要求的影响。风湿科致力于支持她获得独立的努力，并支持一名研究技术人员帮助她实现目标。人们的期望是，她将建立一个研究计划，专注于骨关节炎的炎症途径激活，这是一个刚刚开始出现的研究领域。研究：曾经被认为主要是软骨退行性变的情况，现在我们了解到整个关节(包括骨、滑膜、半月板和关节周围软组织)在骨性关节炎中都发生了改变。发生在骨关节炎关节的最不为人所知的病理变化可能是滑膜(SM)内的炎症。这种炎症可能是一种源头疼痛，可能会刺激某些患者的关节退行性变4。然而，关节和下游介质中确切的炎症刺激仍不清楚。我们最近证实，在寻求手术治疗早期和晚期膝骨性关节炎的大多数患者的关节中都可以检测到促炎细胞因子白介素15(IL-15)。已知这种细胞因子是在某些先天免疫受体Toll样受体(TLRs)激活后产生的，这意味着它们在OA中的活动。IL-15以前没有在OA中被记录，但它的存在意味着TLRs的激活。此外，IL-15的功能可能与骨性关节炎的发病机制有关，包括诱导与疾病有关的酶介质10、11。因此，我们计划验证在半月板损伤和早期OA的背景下，TLR通路的激活导致关节组织诱导IL-15的假设，并进一步验证IL-15参与了OA的滑膜反应和软骨退化的特征。我们将通过以下具体目标来检验这一假说：具体目标1：证明早期膝关节骨性关节炎和膝关节损伤患者产生TLR-2或TLR-4配体，并刺激IL-15的产生。具体目的2：证明HA寡糖和TLR激活在关节病理相关细胞和组织产生IL-15中的作用。具体目的3：探讨IL-15对软骨、滑膜和半月板组织的作用。具体目的4：验证IL-15和TLR激活在小鼠骨性关节炎模型中的主要作用。我们希望这些研究能更好地理解早期骨性关节炎中特定炎症途径的刺激因素和后果，并最终开发出干扰这一途径的新疗法。由于我们目前没有对影响疾病进展的早期骨性关节炎的干预措施，因此确定早期疾病的重要途径是至关重要的。

DESCRIPTION (provided by applicant): Candidate: Carla R. Scanzello, MD PhD is an Assistant Professor of Medicine at Rush University Medical Center (Chicago). She has recently been recruited there to the Faculty of the Department of Medicine (Section of Rheumatology), having completed her Fellowship in Rheumatology at the Hospital for Special Surgery in June 2008. She has a particular interest in the role that inflammation plays in osteoarthritis (OA) pathogenesis, which she began to pursue in earnest as a Rheumatology Fellow. During her Fellowship she designed a research project to characterize synovial cell populations and inflammatory mediators in the synovium of OA patients. Since most previously published work on inflammation in OA had focused on patients with advanced disease, her project was designed to characterize the inflammatory reaction in patients with well-defined early disease. This work has resulted in multiple manuscripts (one published, one accepted, and one under preparation), and observations from this project have led to the hypothesis addressed in this application. This award will allow Dr. Scanzello to gain further training in specific laboratory techniques used in the fields of both Immunology and Cartilage Biochemistry, in order to gain full independence as an investigator. She is committed to pursuing a translational research career working at the intersection between matrix biochemistry and immunology as it applies to OA pathophysiology, with the ultimate goal of developing novel therapies for this common disease in its early stages. Environment: Dr. Scanzello has recently accepted a tenure-track position in pursuit of her goal of becoming an independent investigator. This position allows her the access to resources she will need to accomplish the goals of this proposal. Necessary resources she will have access to include faculty expertise and support, suitable mentorship, accomplished clinical and research collaborators, adequate laboratory space and equipment, and access to appropriate patient populations via the Orthopedics Department. 75% of her time is dedicated for research, with protection from excessive teaching and administrative requirements. The Section of Rheumatology is dedicated to support her efforts to gain independence, and is supporting a research technician to help her accomplish her goals. The expectation is that she will establish a research program with focus on inflammatory pathway activation in Osteoarthritis, an area of research that is just beginning to emerge. Research: Once considered primarily a degenerative cartilage condition, we now understand that the entire joint (including bone, synovium, menisci, and periarticular soft tissues) is altered in OA. Perhaps the least understood pathologic change that occurs in the OA joint is the inflammation within the synovial membrane (SM). This inflammation can be a source pain3, and may stimulate progression of joint degeneration in certain patients4. However the precise inflammatory stimuli in the joint and the downstream mediators remain unknown. We recently demonstrated that the pro-inflammatory cytokine interleukin-15 (IL-15) is detectable in the joints of most patients with knee OA seeking surgical intervention for both early and advanced disease7. This cytokine is known to be produced following activation of certain innate immune receptors, the Toll-like receptors (TLRs), implicating their activity in OA. IL-15 has not been documented in OA previously, but its presence implicates activation of TLRs. Furthermore, IL-15 has functions that may be relevant to OA pathogenesis including induction of enzymatic mediators10,11implicated in disease. Therefore, we plan to test the hypothesis that TLR pathway activation leads to induction of IL-15 by joint tissues in the setting of meniscal injury and early OA, and furthermore that IL-15 contributes to the synovial response and cartilage degradation characteristic of OA. We will test this hypothesis through the following specific aims: Specific Aim 1: To demonstrate that TLR-2 or TLR-4 ligands are produced in patients with early knee OA and mensical injury and stimulate IL-15 production. Specific Aim 2: To demonstrate a role for HA oligosaccharides and TLR-activation in IL-15 production by cells and tissues relevant to joint pathology. Specific Aim 3: To establish the action of IL-15 on cartilage, synovium and meniscal tissue. Specific Aim 4: To verify that IL-15 and TLR activation play central roles in OA pathogenensis in a murine model of OA. We hope that these investigations lead to better understanding of the stimulating factors and consequences of a specific inflammatory pathway in early OA, and ultimately to development of novel therapeutics to interfere with this pathway. As we currently have no interventions for early OA that impact disease progression, defining important pathways in early disease is essential.