Firulli A B, Han D, Kelly-Roloff L, Koteliansky V E, Schwartz S M, Olson E N, Miano J M
Hamon Center for Basic Research, The University of Texas Southwestern Medical Center at Dallas, 75235-9148, USA.
In Vitro Cell Dev Biol Anim. 1998 Mar;34(3):217-26. doi: 10.1007/s11626-998-0127-5.
Transcriptional regulation of smooth muscle cell (SMC) differentiation is a rapidly growing area of interest that has relevance for understanding intimal disease. Despite the wealth of data accumulating in vitro, however, no study has compared the cell-specific marker profile, transfectability, promoter activity, and growth characteristics among several SMC culture systems. Accordingly, we performed a comprehensive analysis of the marker profile, growth properties, transfectability, and SMC promoter activity in four rat SMC lines (A7r5, adult and pup aortic, and PAC1). Despite alterations in chromosomal number and structure, A7r5, adult aortic, and PAC1 cells express all SMC markers studied including SM alpha-actin, SM calponin, SM22, tropoelastin, and to a lesser extent, SM myosin heavy chain (SMMHC). In contrast, pup aortic cells express very low or undetectable levels of all the above markers except tropoelastin. Adult aortic, pup, and PAC1 cells display similar growth curves and levels of proto-oncogene transcripts, whereas those in the A7r5 line are comparatively less. All cell lines studied except pup cells show expression of SMC differentiation genes during active growth, indicating that growth and differentiation are not mutually exclusive in cultured smooth muscle. Transfection studies reveal dramatic differences in DNA uptake and SMC-restricted promoter activity between cell lines. Collectively, these results provide detailed information relating to SMC molecular biology in culture that should facilitate the selection of a cell line for studying the transcriptional regulatory mechanisms underlying SMC differentiation.
平滑肌细胞（SMC）分化的转录调控是一个快速发展且备受关注的领域，对理解内膜疾病具有重要意义。然而，尽管体外积累了大量数据，但尚无研究比较过几种SMC培养系统之间的细胞特异性标志物谱、转染能力、启动子活性和生长特性。因此，我们对四种大鼠SMC系（A7r5、成年和幼鼠主动脉以及PAC1）的标志物谱、生长特性、转染能力和SMC启动子活性进行了全面分析。尽管染色体数量和结构存在改变，但A7r5、成年主动脉和PAC1细胞表达所有研究的SMC标志物，包括平滑肌α-肌动蛋白、平滑肌钙调蛋白、SM22、原弹性蛋白，以及程度较轻的平滑肌肌球蛋白重链（SMMHC）。相比之下，幼鼠主动脉细胞除原弹性蛋白外，所有上述标志物的表达水平都非常低或无法检测到。成年主动脉、幼鼠和PAC1细胞显示出相似的生长曲线和原癌基因转录本水平，而A7r5系的细胞相对较低。除幼鼠细胞外，所有研究的细胞系在活跃生长期间均显示SMC分化基因的表达，这表明在培养的平滑肌中生长和分化并非相互排斥。转染研究揭示了细胞系之间在DNA摄取和SMC限制性启动子活性方面存在显著差异。总体而言，这些结果提供了与培养中的SMC分子生物学相关的详细信息，这将有助于选择用于研究SMC分化潜在转录调控机制的细胞系。
