The Toll-like receptor pathway in Meniscal Injury and Osteoarthritis

描述（由申请人提供）：候选人：Carla R. Scanzello博士是拉什大学医学中心（芝加哥）的医学助理教授。2008年6月，她在特殊外科医院完成了流变学研究金，最近被招募到医学系（流变学科）。她对炎症在骨关节炎（OA）发病机制中的作用特别感兴趣，她开始认真追求作为一名流变学研究员。在她的研究期间，她设计了一个研究项目，以表征关节炎患者滑膜中的滑膜细胞群和炎症介质。由于之前发表的大多数关于OA炎症的研究都集中在晚期疾病患者身上，因此她的项目旨在描述具有明确早期疾病患者的炎症反应。这项工作已经产生了多个手稿（一个已发表，一个已被接受，一个正在编写中），该项目的观察结果导致了本申请中所涉及的假设。该奖项将使Scanzello博士能够在免疫学和生物化学领域使用的特定实验室技术方面获得进一步的培训，以获得作为研究者的完全独立性。她致力于从事基质生物化学和免疫学之间的交叉领域的转化研究，因为它适用于OA病理生理学，最终目标是在早期阶段为这种常见疾病开发新疗法。环境：Scanzello博士最近接受了一个终身职位，以追求成为一名独立调查员的目标。该职位使她能够获得实现本提案目标所需的资源。她将有机会获得必要的资源，包括教师的专业知识和支持，适当的指导，完成临床和研究合作者，足够的实验室空间和设备，并通过骨科获得适当的患者人群。她75%的时间用于研究，免受过多的教学和行政要求。流变学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。期望是，她将建立一个研究计划，重点是骨关节炎的炎症通路激活，这是一个刚刚开始出现的研究领域。研究：一旦被认为主要是一种退行性软骨疾病，我们现在了解到，整个关节（包括骨，滑膜，滑膜和关节周围软组织）在OA中发生改变。也许最不了解的病理变化，发生在OA关节是炎症内的滑膜（SM）。这种炎症可能是疼痛的来源3，并可能刺激某些患者的关节退化进展4。然而，关节中确切的炎症刺激和下游介质仍然未知。我们最近证明，促炎细胞因子白细胞介素-15（IL-15）在大多数寻求手术干预早期和晚期疾病的膝关节OA患者的关节中均可检测到7。已知该细胞因子在某些先天免疫受体Toll样受体（TLR）激活后产生，这暗示了它们在OA中的活性。IL-15以前在OA中没有记录，但其存在涉及TLR的激活。此外，IL-15具有可能与OA发病机制相关的功能，包括诱导与疾病有关的酶介质10，11。因此，我们计划检验以下假设：TLR通路激活导致关节组织在关节损伤和早期OA的情况下诱导IL-15，此外，IL-15有助于OA的滑膜反应和软骨降解特征。我们将通过以下具体目标来检验这一假设：具体目标1：证明TLR-2或TLR-4配体在早期膝关节OA和月经损伤患者中产生，并刺激IL-15产生。具体目标二：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。具体目标3：确定IL-15对软骨、滑膜和关节组织的作用。具体目的4：在OA小鼠模型中验证IL-15和TLR活化在OA发病机制中发挥核心作用。我们希望这些研究能够更好地理解早期OA中特定炎症通路的刺激因素和后果，并最终开发出新的治疗方法来干扰这一通路。由于我们目前没有影响疾病进展的早期OA干预措施，因此确定早期疾病的重要途径至关重要。

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.