Smooth muscle myosin regulation by serum and cell density in cultured rat lung connective tissue cells.
Smooth muscle myosin regulation by serum and cell density in cultured rat lung connective tissue cells.
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培养的大鼠肺结缔组织细胞中血清和细胞密度对平滑肌肌球蛋白的调节。
DOI：
10.1152/ajplung.1993.265.2.l127
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Low,RB
中科院分区：
文献类型：
--
作者：
Babij,P;Zhao,J;White,S;Woodcock-Mitchell,J;Mitchell,J;Absher,M;Baldor,L;Periasamy,M;Low,RB
应用RNA和蛋白质分析技术检测了培养的成年大鼠肺结缔组织细胞（RL-90）中平滑肌肌球蛋白重链（MHC）SM 1和SM 2的表达。在10%血清中生长的汇合细胞中平滑肌MHC mRNA的表达约为成人胃中水平的50%。在1%血清中以低密度（25%汇合）培养的细胞中获得了类似的结果。然而，在低密度培养转移到10%血清24小时，MHC mRNA的水平下降到约20%，在成人胃。平滑肌α-肌动蛋白的表达模式与平滑肌MHC相似。在所有培养条件下，非肌肉MHC-A mRNA的表达均高于胃。低浓度血清培养24 h后，低浓度培养的细胞MHC-A mRNA表达量减少，而10%血清培养24 h后，MHC-A mRNA表达量增加。MHC-B mRNA表达在低密度培养物中比在高密度培养物中少。然而，与MHC-A相反，低密度培养中的MHC-B mRNA表达在低血清中更高。免疫荧光和免疫印迹与SM 1特异性抗体证明了SM 1蛋白亚型的存在，以及反应性的蛋白带迁移略快于SM 2。这些结果表明，培养的大鼠肺结缔组织细胞表达平滑肌MHC和表达的调制培养条件。
RNA and protein analyses were used to detect expression of SM1 and SM2 smooth muscle myosin heavy chain (MHC) in cultured adult rat lung connective tissue cells (RL-90). Smooth muscle MHC mRNA expression in confluent cells grown in 10% serum was approximately 50% of the level in adult stomach. Similar results were obtained in cells cultured at low density (25% confluency) in 1% serum. However, in low-density cultures transferred to 10% serum for 24 h, the level of MHC mRNA decreased to approximately 20% of that in adult stomach. Smooth muscle alpha-actin showed a pattern of expression similar to that for smooth muscle MHC. Expression of nonmuscle MHC-A mRNA was higher in all culture conditions compared to stomach. MHC-A mRNA expression was less in low-density cultures in low serum and increased when low-density cultures were transferred to 10% serum for 24 h. MHC-B mRNA expression was less in low- vs. high-density cultures. In contrast to MHC-A, however, MHC-B mRNA expression in low-density cultures was higher in low serum. Immunofluorescence and immunoblotting with SM1-specific antibody demonstrated the presence of the SM1 protein isoform as well as reactivity to a protein band migrating slightly faster than SM2. These results demonstrate that cultured rat lung connective tissue cells express smooth muscle MHC and that expression is modulated by culture conditions.