SOX9介导TGF-β/Smads/wnt和β-catenin信号通路调控青少年椎体骺板软骨的分化

Adolescent linear growth depends on the differentiation of spinal vertebral epiphyseal plate , but the regulatory mechanism is unclear. to data, SOX9 and β-catenin signaling plays an important role in the differentiation.of cartilage. Our previous studies had proved that, vertebral linear growth is regulated by TGF-β/Smads/wnt signaling pathways.Accordingly, we assume that SOX9 regulate differentiation of adolescent vertebral epiphyseal plate chondrocytes directed to differentiate into osteoblasts by mediating TGF-β/Smads/wnt and β-catenin signaling pathway, regulating the spinal vertebrae linear growth. Our approach is that SOX9-shRNA gene silencing lentivirus vector were built with the RNAi technology, and transfected into chondrocytes and mice to establish SOX9 gene silencing cell and animal models,while SOX9 lentivirus vector was transfected into knockout mice,to study the role of regulation of SOX9 to youth vertebral epiphyseal plate differentiation, and the regulation of major signaling factors to observe the differentiation of vertebral epiphyseal plate chondrocyte in vitro and in vivo, respectively. Expected, experiments may reveal the function ofSOX9 in regulating the linear growth of the adolescent vertebral spine by mediating TGF-β/Smads/wnt and β-catenin signaling pathway,. lay the foundation for candidate therapeutic targets, clinical decision-making and therapeutic markers.

椎体骺板软骨定向分化是青少年脊柱线性生长的关键，其调控机制尚不清楚。据研究，SOX9和β-catenin信号传递在软骨分化过程中发挥重要作用。我们前期研究也证明，TGF-β/Smads/wnt信号通路调控椎体线性生长。据此，我们推断：SOX9调节TGF-β/Smads/wnt和β-catenin信号通路调控青少年椎体骺板软骨细胞定向分化为成骨细胞，进而调控其脊柱的线性生长。我们拟采用RNAi技术，建立SOX9等基因沉默细胞模型和动物模型，并用SOX9表达载体转染基因敲除小鼠，于体外和体内分别研究SOX9对青少年椎体骺板分化的作用，及其对主要信号因子的调控，观察椎体骺板软骨细胞定向分化的情况，以期揭示SOX9介导的TGF-β/Smads/wnt和β-catenin信号通路在青少年椎体线性生长发育中的调控机制，为青少年脊柱发育异常等疾病的诊治寻找新的早期诊断候选标记物和治疗的新靶点奠定基础。

椎体骺板软骨定向分化是青少年脊柱线性生长的关键，其调控机制尚不清楚。据研究，SOX9 和β-catenin 信号传递在软骨分化过程中发挥重要作用。作为软骨发育的主要调控因子，Sox9 参与了体内软骨发育的主要环节，任何一个环节发生紊乱都可能导致脊柱的不平衡生长从而引发脊柱侧凸，本项目研究过程中，我们通过对AIS患者原代软骨细胞Sox9 及软骨特异性标记物CollagenⅡ和aggrecan的表达及椎体软骨内成骨过程进行研究，在分子水平进一步揭示了AIS的发病机制。另一方面，本研究显示miR-30a在MSC软骨分化过程中表达逐渐上升并具有负调节作用。其作用机制为，miR-30a直接结合Sox9 3'UTR区域，抑制其表达，进而干扰软骨分化。 此外，miR-30a的过表达导致Sox9表达的进一步降低，从而抑制MSC的软骨分化。 我们的研究表明AIS患者体内原代软骨细胞中Sox9及软骨特异性标记物CollagenⅡ和aggrecan与正常对照组患者原代软骨细胞相比存在表达差异；miR-30a作为调控MSC软骨分化的潜在靶点，对于软骨再生和软骨发育相关疾病的应用和防治具有重要意义。