Prevention of Cartilage Degeneration Associated with Meniscal Injury

在骨科创伤的背景下，本项目建议评估骨关节炎与骨关节炎之间的关系。 损伤和骨关节炎（OA）的发展。已记录了显著的临床相关性 创伤性半月板损伤和OA之间的联系，但半月板损伤的机制 直接或间接诱发发病机制尚不清楚。最近，我们已经确定， 由泛素连接酶Smurf 2的过度表达诱导的软骨细胞TGF-β信号转导的丧失导致 小鼠中的OA样表型。此外，我们已经确定了Smurf 2在人类中的上调， 关节软骨损伤后不久。基于这些发现，我们假设蓝精灵2 上调是关节炎过程中的种子事件，随后是关节损伤。此外，根据 我们的发现是，BMP信号的增加与关节的不适当成熟有关 我们还假设通过遗传或基因治疗减少BMP信号传导， 这些方法将减缓由关节损伤诱导的鼠OA中的疾病进展。解决这些 中心假设，我们建议解决以下3个具体目标：在目标1，我们将全面 在小鼠OA模型中表征导致软骨退化的组织和分子事件 由尿道损伤引起的。在目标2中，我们将使用遗传和基因治疗方法来评估一种 在该鼠OA模型中的候选治疗干预是基于BMP信号传导的减少。 为了实现这些基础科学目标，我们将采用MRI和microCT成像方法，组织形态计量学和 分子分析以评估疾病表型。然后，在目标3中，将执行人体临床研究 其将使用定量分析来量化急性关节损伤后关节软骨结构的变化。 MRI方法。分子变化也将在丢弃的软骨和半月板组织中进行评估，以进一步 评估Smurf 2在损伤后OA疾病发病机制中的参与。

In the context of orthopaedic trauma, this project proposes to evaluate the relationship between meniscal injury and the development of osteoarthritis (OA). A significant clinical association has been documented between traumatic meniscal injury and OA, but the mechanism(s) behind how damage to the meniscus either directly or indirectly induces pathogenesis are not known. Recently, we have determined that articular chondrocyte loss of TGF-beta signaling induced by over-expression of the ubiquitin ligase Smurf2 leads to an OA-like phenotype in the mouse. Furthermore, we have identified up-regulation of Smurf2 in human articular cartilage shortly following meniscal trauma. Based on these findings, we hypothesize that Smurf2 up-regulation is the seminal event in the arthritic process the follows meniscal injury. Furthermore, based on our findings that increased BMP signaling occurs in conjunction with inappropriate maturation of articular chondrocytes during OA, we also hypothesize that reduction of BMP signaling via genetic or gene therapy approaches will decelerate disease progression in murine OA induced by meniscal injury. To address these central hypotheses, we propose to address the following 3 Specific Aims: In Aim 1, we will comprehensively characterize the tissue and molecular events leading to cartilage degeneration in a model of murine OA induced by meniscal injury. In Aim 2, we will use genetic and gene therapy approaches to evaluate a candidate therapeutic intervention in this murine OA model that are based on reduction of BMP signaling. For these basic science aims, we will employ MRI and microCT imaging methods, histomorphometry and molecular analyses to evaluate disease phenotype. Then, in Aim 3, a human clinical study will be executed which will quantify articular cartilage structural changes following acute meniscal injury using a quantitative MRI approach. Molecular changes will also be assessed in discard cartilage and meniscus tissue to further evaluate the involvement of Smurf2 in the pathogenesis of OA disease following injury.