蛋白激酶C抑制剂对人角膜基质细胞增殖周期的调控作用

目的 探讨蛋白激酶C(PKC)的抑制剂星状孢菌素(ST)对人角膜基质细胞在G1／S时相阶段的调控作用及分子机制。方法 流式细胞仪(FCM)测量PKC抑制剂ST对人角膜基质细胞周期的影响,cyclin／DNA双参数法检测细胞周期蛋白E(cyclin E)蛋白含量。结果 ST使人角膜基质细胞阻滞在G1期,实验组G1期细胞百分比(2．5μg/L ST组为78．4％,5μg/L ST组为90．9％)明显高于对照组(72．4％),并呈现剂量依赖性;cyclin／DNA双参数流式细胞术分析显示ST使G1期细胞cyclin E蛋白水平下降,同时G1期细胞数增加。结论 PKC抑制剂ST能调控人角膜基质细胞的周期,并在G1／S时相发挥其抑制细胞生长的作用。

Modulation of PKC inhibitor on growth cycle of human keratocyte

OBJECTIVE: To study the effects of staurosporine (ST), an inhibitor of protein kinase C (PKC), on the cell cycle of cultured human keratocyte at G(1)/S phase transition and to study the molecular mechanism of this process. METHODS: Flow cytometry technique was used to define the effect of ST on the cell cycle of cultured human keratocyte. Cyclin E protein levels of corneal keratocyte were analyzed by using the cyclin/DNA two parameter flow cytometry. RESULTS: Treatment of ST (2.5 microg/L and 5 microg/L) for 18 hours blocked the growth of keratocyte in G(1) phase; the percentage of cells staying in G(1) phase was increased from 72.4% in the control group to 78.4% (group 2.5 microg/L ST) and 90.9% (group 5 microg/L ST), respectively. This effect was dose dependent. Cyclin E protein level in G(1) phase was decreased from 75.6% in the control group to 62.0% (group 2.5 microg/L ST) and 51.1% (group 5 microg/L ST) in cells treated with ST. CONCLUSIONS: PKC activity is important in promoting keratocyte proliferation. Inhibition of PKC activity prohibits G(1)/S phase progress and reduces cyclin E protein level. Inhibitor of PKC is involved in the modulation of the cell cycle of human keratocyte and may play an important role in inhibiting cell growth in G(1)/S phase.