Cell cycle-dependent regulation of elastin gene in cultured chick vascular smooth-muscle cells.
Cell cycle-dependent regulation of elastin gene in cultured chick vascular smooth-muscle cells.
复制标题
培养鸡血管平滑肌细胞中弹性蛋白基因的细胞周期依赖性调节。
作者：
H. Wachi;Yoshiyuki Seyama;S. Yamashita;Shingo Tajima
研究了弹性蛋白表达与鸡血管平滑肌细胞增殖状态的关系。原代培养的汇合细胞通过血清剥夺72 h进入静止状态，其弹性蛋白合成、弹性蛋白mRNA水平和弹性蛋白基因转录活性分别比增殖状态的细胞增加5倍、3.5倍和2倍。在再添加血清中的血清剥夺培养，细胞开始增殖，和弹性蛋白的合成，其mRNA水平和转录的基因在24小时内下降到增殖状态的水平，表明弹性蛋白在平滑肌细胞中的表达是由它们的生长状态至少部分地在转录水平控制。当细胞悬浮培养72 h后，弹性蛋白mRNA水平明显增加。当细胞同步化在G1/S期与胸苷/羟基脲处理，弹性蛋白的表达在G1/S期大于在G2/M期的细胞周期。在细胞周期过程中，无血清或悬浮培养引起的G 0期弹性蛋白mRNA水平高于G1/S期。这些结果表明，弹性蛋白的基因表达和细胞周期是紧密耦合的，这是不依赖于血清或粘附状态的存在，弹性蛋白的表达可能是一个生化标记的平滑肌细胞的生长状态。
A study was made of the relationship between elastin expression and the proliferative state of chick vascular smooth-muscle cells. Confluent cells of primary culture brought to a quiescent state by the deprivation of serum for 72 h exhibited a 5-, 3.5- and 2-fold increase in elastin synthesis, elastin mRNA level and transcriptional activity of elastin gene respectively over those in the proliferative state. On re-addition of serum in serum-deprived culture, cells started to proliferate, and elastin synthesis, its mRNA level and transcription of the gene decreased to the level of a proliferative state within 24 h, indicating that elastin expression in smooth-muscle cells was controlled by their growth states at least in part at a transcriptional level. A comparable increase in elastin mRNA level was observed when the cell growth was arrested by suspension culture for 72 h. When the cells were synchronized at the G1/S phase with thymidine/hydroxyurea treatment, elastin expression at the G1/S phase was greater than that at the G2/M phase during cell cycling. Elastin mRNA level at the G0 phase brought about by serum-deprivation or suspension culture predominated over that at the G1/S phase during cell cycling. These results indicate that gene expression of elastin and cell cycle are tightly coupled, which is independent of the presence of serum or adhesive state, and that elastin expression could be a biochemical marker for the growth states of smooth-muscle cells.