中文摘要：

目的 研究低切应力（low shear stress, LowSS）诱导的血管平滑肌细胞（vascular smooth muscle cells, VSMCs）迁移功能异常在动脉粥样硬化血管重建病理过程中的作用及其分子机制。 方法 应用双向凝胶电泳结合质谱分析的差异蛋白质组学方法，研究1.5 Pa正常切应力（normal shear stress, NSS）与0.5 Pa LowSS条件下培养血管组织的蛋白质差异表达谱。应用血管内皮细胞（endothelial cells, ECs）与VSMCs联合培养的平行平板流动腔系统，分别施加NSS和LowSS，Western blot检测ECs与VSMCs的Rab28表达水平以及VSMCs的磷酸化ERK表达水平；Transwell法检测VSMCs的迁移能力；RNA干扰和PD98059分别特异性抑制VSMCs的Rab28表达和ERK磷酸化，再观察VSMCs迁移能力变化。结果 血管差异蛋白质组学的结果发现，与NSS组相比，Rab28在LowSS组血管组织的表达水平明显升高。细胞实验结果显示，LowSS加载明显上调VSMCs的Rab28蛋白表达、VSMCs迁移和ERK磷酸化。静态条件下RNA干扰抑制单独培养VSMCs的Rab28表达，VSMCs迁移能力明显降低，但ERK磷酸化水平无明显变化；应用PD98059特异性抑制VSMCs的ERK磷酸化，VSMCs迁移能力和Rab28表达水平均明显降低。结论 LowSS可能通过上调VSMCs的ERK磷酸化水平引起Rab28表达水平增加，从而诱导VSMCs迁移。探讨Rab28及其相关信号通路在切应力调控VSMCs功能中的作用及其机制，可能为深入理解动脉粥样硬化血管重建疾病发病机制和寻找新的药物治疗靶点提供力学生物学依据。

英文摘要：

Objective To study the role of abnormally changed migration of vascular smooth muscle cells （VSMCs） induced by low shear stress （LowSS） in vascular remodeling during atherosclerosis as well as the molecular mechanism involved in this process. Methods By using comparative proteomic analysis with two-dimensional electrophoresis combined with mass spectrometry, differential protein expression profiles of cultured vascular tissues under normal shear stress （NSS） （1.5 Pa） and LowSS （0.5 Pa） were studied. Using endothelial cells （ECs） and VSMCs co-cultured parallel plate flow chamber system, two levels of shear stress i.e. LowSS and NSS, were applied, respectively. Western blot was used to detect the protein expressions of Rab28 and phosphor-ERK. Transwell system was used to detect the migration ability of VSMCs. After using RNA interference and ERK inhibitor PD98059 to decrease the expressions of Rab28 and phosphor-ERK, respectively, the migration ability of VSMCs was observed again. Results The expression of Rab28 in the cultured rat aorta was significantly up-regulated by the LowSS （0.5 Pa） application in comparison with the NSS （1.5 Pa）. The migration, expressions of Rab28, and phosphorylation of ERK in VSMCs were significantly increased by the LowSS application. Target RNA interference of Rab28 significantly decreased the migration of VSMCs, but had no specific effect on the phosphorylation of ERK. Target inhibitor of ERK, PD98059, significantly decreased both the migration and Rab28 expression in VSMCs. Conclusions The LowSS may increase the phosphorylation of ERK and then increase the expression of Rab28 in VSMCs, which subsequently modulate VSMC migration during vascular remodeling. The investigation on the role of Rab28 and its signal path in LowSS-regulated VSMCs as well as the molecular mechanism might provide a biomechanical reference for understanding the pathogenesis of vascular remodeling during atherosclerosis and finding the therapeutic target of new drugs.