中文摘要：

目的：观察血小板源性生长因子BB（PDGF-BB）对血管平滑肌细胞（VSMCs）增殖及分化相关基因表达的影响,探讨其可能的机制。方法：分离体外培养的SD大鼠胸腹主动脉VSMCs,分为空白对照组和不同浓度PDGF-BB处理组。分别采用MTT法、流式细胞术和伤口愈合实验检测PDGF-BB对VSMCs增殖、细胞周期和迁移活性的影响;用W estern b lotting分析检测VSMCs表型标志物的表达;用免疫沉淀和免疫共沉淀分析检测Krüppel样因子4（KLF4）磷酸化及与其它转录因子的相互作用。结果：PDGF-BB促进VSMCs增殖和迁移;上调增殖相关蛋白PCNA的表达,下调增殖抑制蛋白p27、分化相关蛋白SM22α的表达。PDGF-BB诱导KLF4的表达和磷酸化,促进KLF4与NF-κB的相互作用,抑制KLF4与Sm ad3、HDAC2的结合。结论：PDGF-BB可能通过影响KLF4磷酸化及其与不同转录调节因子的相互作用而诱导VSMCs表型转化。

英文摘要：

AIM：To study the effect of platelet-derived growth factor（PDGF）-BB on the expression of phenotypic markers in vascular smooth muscle cells（VSMCs） and to investigate the underlying mechanisms in phenotypic switching and proliferation of VSMCs.METHODS： Cultured rat VSMCs were treated with PDGF-BB.The cell viability and cell cycle were detected by MTT assay and flow cytometry,respectively.The cell migration was examined by wound-healing assay.The protein expression was examined by Western blotting.Immunoprecipitation and co-immunoprecipitation were used to detect KLF4 phosphorylation and its interaction with other transcription factors,respectively.RESULTS： PDGF-BB induced the proliferation and migration of VSMCs.PDGF-BB increased the expression of PCNA,KLF4 and phosphorylated KLF4,and reduced the levels of p27 and SM22α.Moreover,the interaction of KLF4 with NF-κB was increased,and the interaction of KLF4 with Smad3 or HDAC2 was decreased by the action of PDGF-BB.CONCLUSION： KLF4 plays a role in the proliferation of VSMCs induced by PDGF-BB,which is related with its phosphorylation and the interaction with other transcription factors.