血清饥饿可诱导人血管平滑肌细胞再分化  

Redifferentiation of Cultured Human Vascular Smooth Muscle Cells after Serum Deprivation

作　　者：韩梅[1] 温进坤[1] 郑斌[1] 聂磊[1] 

机构地区：[1]河北医科大学基础医学研究所,河北省医学生物技术重点实验室,石家庄050017

出　　处：《中国生物化学与分子生物学报》2003年第2期250-255,共6页Chinese Journal of Biochemistry and Molecular Biology

基　　金：国家自然科学基金 (No.30 2 70 499);国家"973"基金 (G2 0 0 0 0 5 690 5 Z);河北省自然科学基金资助项目 (No.30 135 8)~~

摘　　要：体外培养的分化型血管平滑肌细胞 (vascularsmoothmusclecells ,VSMC)以特异性标志基因表达、长梭形外观及对兴奋剂刺激产生收缩反应为其表型特征 .以血清饥饿法培养处于超汇合 (overconfluence)状态的人VSMC ,观察其分化型标志基因表达活性及其与细胞形态特征和收缩反应性之间的关系 ,探讨细胞生存环境对VSMC基因表达及表型的影响 .研究显示 ,生长至超汇合的VSMC由含血清培养转为血清饥饿后 ,收缩蛋白如SMα肌动蛋白 (SMα actin)、SM2 2α、h1 calponin、肌球蛋白重链 (MHC)SM1和SM2亚型的表达活性明显上调 ,证实血清饥饿诱导的收缩蛋白基因表达和血清应答因子 (serumresponsefactor ,SRF)与CArG顺式元件结合活性的增强有关 .同时 ,血清饥饿还可激活参与VSMC分化调节的转录调控因子SmLIM、Gax和分化相关蛋白HRG 1基因的转录 .随着血清饥饿培养时间的延长 ,VSMC逐渐形成多层、束状、成极性排列的形式 ,对兴奋剂刺激产生的收缩反应明显增强 .结果表明 ,超汇合状态的去分化型VSMC脱离血清刺激后 。Differentiated vascular smooth muscle cells (VSMC) are characterized as expression of specific marker genes, elongated and spindle-shaped morphology and the ability to contract in response to agonist stimulation. To determine whether human VSMC phenotype could revert from dedifferentiation to differentiation, over confluent VSMC was incubated in serum-free M199, and expression of differentiation marker genes was detected by RT-PCR, Northern blotting and Western blotting. The relationships between attainment of a contractile phenotype and expression of differentiation marker genes were investigated. The results indicated that over confluent VSMC after serum withdrawal sequentially expressed specific contractile proteins, including SM α-actin, SM-MHC isoforms SM1 and SM2, h1-calponin and SM22α. During prolonged periods of “starvation”, the increases in the expression of marker genes were associated with elevation of SRF binding to CArG cis-elements. On serum withdrawal, VSMC expressed the transcription factors that are necessary for regulating VSMC differentiation, such as SmLIM, Gax and HRG-1, which were restricted in differentiated VSMC expression and undetectable before serum withdrawal. After serum removal, these cells organized to form elongated, dense, multilayered cell bundles, and had the ability to contract in response to agonist stimulation. It was demonstrated that over confluent VSMC could revert from a dedifferentiated state to a contractile, differentiated state, and restore agonist-induced contraction.

关 键 词：血管平滑肌细胞 再分化 表型转化 标志基因 细胞功能 血清饥饿培养 收缩蛋白 收缩调节蛋白 基因表达 

分 类 号：R331.32[医药卫生—人体生理学] R329.28[医药卫生—基础医学]