周期性压力促成软骨分化效应及其信号转导通路机制的研究

Recently, the effect of biomechanical compressive stimulation in regenerative medicine has been investigated widely. Our previous research demonstrated that cyclic compression could improve the proliferation and chondrogenic differentiation. However, the mechanism of these influences is still unclear. As we know, signal pathways play an essential role in the regulation of cellular biological activities. We hypothesize that cyclic compression can effect and activate some signal pathways, which will lead to the proliferative and differentiative effect. In this study, we are aiming to screen the signal pathways and enzymes activated by cyclic compression with protein and high-throughput screening assays. Further, we will explore importance of the activated signal pathways and enzymes in cell proliferation and chondrogenic differentiation with some signal pathway inhibitors. The relationship between the parameters of cyclic compression and the activated signal pathways will be fully investigated as well, hoping to find the specific signal pathway or enzyme activated by cyclic compression. Finally, we believe this project will explain the mechanism of proliferative and chondrogenesis-differentiative effect of cyclic compression, provide a reliable theoretical basis for parameter selections, and serve the clinical cartilage reconstruction by means of tissue engineering ultimately.

近年来，机械压力刺激在组织工程领域中的应用受到广泛的关注，我们的前期研究发现周期性压力可以促进人骨髓间充质干细胞增殖并向软骨样细胞分化。然而，我们对机械压力促增殖和成软骨分化的机制尚不清楚。信号通路在调节细胞生物学活动方面发挥着重要作用，我们推测周期性压力会作用于一些信号通路，引起信号通路的激活，通过信号通路的传导和放大效应最终产生了促增殖和促成软骨分化效应。本项目拟通过基因芯片技术和高通量信号通路筛选试剂盒等筛查出周期性压力激活的信号通路和酶，继而使用通路阻滞剂等研究激活的信号通路和酶在周期性压力促细胞增殖和成软骨分化中的重要性以及各激活酶之间的相互联系等，并着重探讨周期性压力激活的信号通路及同其效应之间的关系，希望找到周期性压力作用的特异性信号通路或酶，为在分子水平解释周期性压力的促增殖和成软骨效应奠定基础，为周期性压力刺激在临床组织工程化软骨中的应用提供可靠的理论依据和参数选择依据。

机械压力刺激在组织工程领域中的应用受到广泛的关注，我们的前期研究发现周期性压力可以促进人骨髓间充质干细胞增殖并向软骨样细胞分化。信号通路在调节细胞生物学活动方面发挥着重要作用，我们推测周期性压力会作用于一些信号通路，引起信号通路的激活，通过信号通路的传导和放大效应最终产生了促增殖和促成软骨分化效应。本研究中，我们设计并组装新型多层复合仿生支架，表征其力学特征及生物相容性。利用生物力学反应器对接种于支架上的骨髓间充质干细胞进行周期性压力刺激，检测成软骨相关指标，并探寻周期性压力激活的相关信号通路。建立迷你猪单侧股骨髁软骨缺损模型，观察仿生支架和迷你猪骨髓干细胞复合体对软骨缺损的修复效果。.研究表明，新型仿生支架具备良好的压缩模量和生物相容性。该支架利于骨髓间充质干细胞增殖并分化为软骨细胞。周期性压力刺激骨髓间充质干细胞成软骨分化效应明显，此过程中，TGF-β/MAPKs（p38，Erk1/2），Smads，BMP等通路的激活均参与其中。Smad1/5，Smad2/3，p38，BMP与周期性压力促间充质干细胞成软骨正相关；Erk1/2与周期性压力促间充质干细胞成软骨负相关。.我们设计制备的新型仿生支架表现出良好的临床应用前景；本研究确认了周期性压力作用的特异性信号通路，在分子水平解释了周期性压力的促增殖和成软骨效应，为周期性压力刺激在临床组织工程化软骨中的应用提供可靠的理论依据和参数选择依据。