SRF在VSMC再分化过程中的表达及其DNA结合活性变化

Expression and DNA binding ability of SRF in the process of VSMC redifferentiation

目的探讨SRF在血管平滑肌细胞(VSMC)再分化过程中的表达及其与DNA结合活性的变化规律。方法采用血清刺激与饥饿的方法诱导培养的VSMC发生表型逆转,应用Northern、W estern印迹及电泳迁移率变动分析(EMSA)等方法检测VSMC再分化过程中SRF表达及其与DNA结合活性的动态变化。结果在体外培养的VSMC发生表型逆转时,SRF的mRNA和蛋白表达的水平均无明显变化;与去分化型VSMC相比,分化型VSMC中SRF的DNA结合活性明显增强,后者与VSMC分化型标志基因SM22α的转录活性具有平行关系。结论SRF启动VSMC特异性基因表达的活性与其蛋白水平无关,血清饥饿诱导的SRF结合CArG-box的能力明显增强,有利于激活分化型标志基因的表达。

Objective To determine SRF expression and binding ability between serum response factor（SRF） and DNA in the process of vascular smooth muscle cell（VSMC） reclifferentiation. Methods The model of VSMC redifferentiation induced by serum starvation was used to reverse VSMC phenotype, The expression and binding ability between SRF and DNA were detected by Northern blotting, Western blotting and EMSA. Results The mRNA and protein level of SRF had no changes during VSMC phenotypic reverse induced by sertan starvation. But compared with dedifferentiated VSMC, the binding activity between SRF and DNA obviously enhanced in differentiated VSMC,. The latter was positive relation to transcription activity of VSMC marker gene SM22α. Conclusions The activity that SRF starts VSMC specific gene expression is unrelated to its protein hvel, It makes for activating differentiated phenotype marker gene expression that SRF induced by serum starvation binding with CArG-box obviously enhance.