TGFβ-Runx2-Mmp13通路参与大骨节病发病的机制及干预该通路对大骨节病影响的研究

Degradation and impaired differentiation of articular cartilage is the pathological feature of KBD, also is the important process of OA development. but its molecular mechanism has not yet been elucidated. Transforming growth factor beta (TGF- beta) signaling pathway plays an important role in the control of chondrocyte differentiation, TGF- beta expression was abnormal in cartilage chondrocytes from patients with Kashin–Beck disease. Our preliminary studies demonstrated that chondrocyte-specific deletion of the type II TGFβ receptor gene, Runx2 and Atf4 expression was significantly increased ,inhibition of TGF beta signaling can up regulate the expression of Mmp13 and Adamts5. Based on these observations,in the proposed studies we will determine the signaling mechanism of the TGFβ inhibition->Runx2/ATF4->Mmp13/Adamts5 pathway in articular chondrocytes using comprehensive molecular and genetic approaches. We have proposed three specific aims to test our hypothesis: (1) The relationship between TGF beta signaling pathway on survival of cartilage cells and the pathogenesis of KBD: Comparison of Kaschin Beck disease and non KBD group TGF- beta, Runx2, ATF4, Mmp13 and Adamts5 gene expression level, statistical analysis. (2) we will determine the role of Mmp13 in KBD. Our hypothesis is that TGF-β signaling inhibition-induced Mmp13 expression is mediated by transcription factors Runx2. (3) The function of Adamts5 in KBD.Our hypothesis is that deletion of Adamts5/Mmp13 genes will have better protective effect than deletion of Mmp13 and Adamts5 alone on articular cartilage.Our proposed studies will provide novel insights into the molecular mechanisms of KBD development.

软骨深层坏死和分化障碍是大骨节病（KBD）的病理特征, 但其分子机制至今尚未被阐明。转化生长因子-β（TGFβ）信号通路在控制软骨细胞分化过程中起重要作用，KBD病人软骨和体外培养的KBD软骨细胞低表达TGFβ，我们前期实验发现，TGFβ受体基因沉默的软骨细胞， Runx2 和 转录调节因子ATF4的表达明显升高，抑制 TGFβ信号通路可以上调Mmp13 和 Adamts5的表达。基于此，利用分子生物、基因遗传等技术探讨TGF β - Runx2 - Mmp13 通路影响大骨节病的分子机制。将从三方面来验证我们的假设：(1) TGFβ信号通路对软骨细胞存活的影响及与KBD发病的关系。(2) Mmp13通过Runx2和ATF4在KBD中的作用及分子机制。(3) Adamts5在KBD中的作用。探讨TGF-β信号通路调节影响大骨节病的分子机制，为临床治疗提供新途径。

软骨深层坏死和分化障碍是大骨节病（KBD）的病理特征, 但其分子机制至今尚未被阐明。转化生长因子-β（TGFβ）信号通路在控制软骨细胞分化过程中起重要作用，KBD病人软骨和体外培养的KBD软骨细胞低表达TGFβ。基于此，利用分子生物、基因遗传等技术探讨了TGFβ-Runx2-Mmp13通路影响大骨节病的分子机制。结果发现，大骨节病患者中TGF-β通路信号分子表达水平异常。体外构建的类似于大骨节病的软骨细胞损伤模型，确定了大骨节病软骨损伤涉及的相应通路分子信号调控网络。通过对大骨节病病人以及健康人群全血中分离的总单核细胞进行了RNA测序分析，通过原始数据整理与质量分析、差异表达基因鉴定、差异基因功能富集及基因结构分析，发现相比健康人群，大骨节病病人的转录组都有明显的变化。鉴定得到45,612个lncRNA，差异表达lncRNA共5,861个。基于预测软件共识别circular RNA 24372个，其中已知circRNA有11980个，新的circRNA有12392个。检测到3,645 个miRNA，其中已知miRNA 1,789 个，新预测miRNA 1,856 个。并在陕西和青海大骨节病人群中进行验证，分析了lncRNA、circRNA及miRNA异常与大骨节病的关联性。.通过项目的实施，首次诠释了TGF-β-Runx2/ATF4-Mmp13/Adamts5通路对大骨节病发病的影响，探讨了其对大骨节病发病影响的分子机制，为揭示KBD的发病机制提供了新的实验依据。