摘要
利用转录因子“诱骗”策略 ,阻断血管平滑肌细胞 (VSMC)表型特异基因和增殖相关基因的反式激活 ,揭示VSMC表型转化和增殖之间的关系 .电泳迁移率改变分析结果表明 ,相当于分化型VSMC特异表达基因共有顺式元件CArG和细胞增殖相关基因共有顺式元件E2F的双股寡核苷酸(ODNs)可分别与从分化型和去分化型VSMC中提取的核蛋白特异性结合 ,形成DNA 蛋白质复合物 .Northern杂交结果显示 ,导入VSMC中的CArGODN可使平滑肌α肌动蛋白 (α actin)表达活性降低 ,肌丝数量减少 ,明显抑制转染细胞的再分化过程 .去分化型VSMC被E2FODN转染后 ,增殖相关基因c myc表达受到抑制 ,细胞增殖速率减慢 ,去分化表型特征减弱 .结果提示 ,E2F和CArG调控元件分别对VSMC增殖和分化起重要调节作用 ,并证实VSMC表型转化与增殖是两个密切相关但不完全相同的细胞事件 .
The relationships between the phenotypic modulation and proliferation of vascular smooth muscle cells(VSMC) were studied by transcription factor“decoy”strategy in which the activation of VSMC\|specific expression genes and proliferation\|associated genes was blocked.The results of gel mobility shift assay showed that the nuclear extracts from differentiated VSMC could bind to CArG double\|stranded oligodeoxynucleotide(ODN),which is a consensus cis \|element for differentiated VSMC\|specific expression genes,and that those from dedifferentiated VSMC could interact with E2F ODN,which is a consensus cis sequence for the genes involved in cell cycle regulation.Transfection of redifferentiating VSMC with GArG ODN could inhibit the expression of smooth muscle α\|actin gene,decrease myofilament content,and prevent redifferentiating of VSMC.Transfection of dedifferentiated VSMC by E2F ODN might result in down\|regulation of \%c\|myc\% gene expression,inhibition of VSMC proliferation,and attenuation of phenotypic characteristics of dedifferentiated VSMC.These results suggest that E2F and CArG cis\|elements might play an important role in VSMC proliferation and differentiation.
出处
《中国生物化学与分子生物学报》
CAS
CSCD
北大核心
2001年第5期626-630,共5页
Chinese Journal of Biochemistry and Molecular Biology
基金
国家自然科学基金资助项目 (No .3 9970 2 74)
河北省自然科学基金资助项目 (No .3 0 13 5 8)
