细胞外基质间隙流动对胚胎软骨分化调控影响的同步辐射研究

Extracellular matrix (ECM) clearance flow was the crucial mechanical mechanism for cartilage surviving and stress dispersion,but the relationship between the clearance flow and embryo cartilage growth was obscure . Based on the porous elastic model which from biphase model theories, the Iopamiro pre-saturated embryo cartilage specimens were undergone circulating loading and their synchrotron phase-contrast images were performed. Then the ECM clearance flow data and theoretical simulation were obtained. The space-time relationships were assessed, which between ECM flow distribution and embryo cartilage collagen phenotypes, TGF-β expression and Sox9 gene expression. The differentiation regulation markers were compared in the exogenous TGF-β cultivated homological cartilage cells and embryo cartilage tissue. As the result, the relationship between the circulating loading, cartilage ECM flow distribution and cartilage differentiation mechanisms could be expounded. And it would be the essential for the tissue engineering cartilage development, cartilage simulation and early damage repair mechanism in osteoarthritis cartilage.

关节软骨细胞外基质（ECM）间隙流动是保证软骨细胞生存和正常载荷分散的重要力学机制，但间隙流动与胚胎软骨发育关系尚不明确。本课题依据两相模型理论所建立的软骨基质多孔弹性模型，通过分析循环负荷下对比剂预饱和胚胎软骨同步辐射相衬图像，建立胚胎软骨ECM间隙流动的实验模型和理论模拟。同步分析循环负荷下ECM不同流场区域胚胎软骨细胞胶原表型、TGF-β细胞因子和Sox9基因表达的空间-时间四维关系。比较同源、同负荷条件下外源性TGF-β培养软骨细胞与胚胎组织分化调控标记物表达水平。初步阐明软骨循环力负荷-ECM流场-软骨细胞分化表达作用轴机制，为创立体外组织工程化软骨发育新途径、软骨仿生和研究骨关节炎软骨早期损伤和修复提供机制研究基础。

关节软骨细胞外基质（ECM）间隙流动是保证软骨细胞生存和正常载荷分散的重要力学机制，但其与软骨组织发生发育、损伤和退变的关系尚不明确。本项目探究了软骨发生发育及损伤过程中软骨组织的生物力学性能与细胞外基质结构变化之间的关系，并在软骨细胞层面探讨可抑制软骨细胞凋亡与细胞外基质退变的基因作用靶点。利用同步辐射X线相位对比成像技术，测定了胚胎软骨中两种造影剂碘帕醇（3.25 ± 0.71×10-10 m2/s）和碘克沙醇（2.35 ± 0.65×10-10 m2/s）的扩散系数（p < 0.05），为进一步观察软骨基质间隙流动提供了依据。基于micro-CT成像技术，发现了受损软骨组织在循环负荷作用下短时间内软骨辐射层造影剂浓度变化较正常软骨组织出现明显改变，正常成熟软骨组织的辐射层上部对承担压缩载荷起到重要作用，而受损软骨组织的辐射层下部也参与承担压缩载荷。通过研究AntimiRNA-30b对软骨组织退变的调控机制，发现抑制miR-30b可增强细胞保护性自噬、抑制软骨退变，并对TNF-α诱导的ATDC5细胞凋亡有保护作用。本项目通过探究生物力学对软骨组织发生发育、损伤和退变的作用机制，为今后软骨仿生、体外软骨培育以及软骨组织损伤（如骨关节炎）的诊断与治疗提供了供实验和理论依据。