血管紧张素Ⅱ和血小板源生长因子对血管平滑肌和心肌细胞细胞周期素及P27蛋白的不同影响

Different expressions of cyclins and cyclin dependent kinase inhibitor P27 in vascular smooth muscle cells and cardiac myocytes caused by angiotensin Ⅱ and PDGF stimulation

目的 观察血管紧张素Ⅱ (AngⅡ )和血小板源生长因子BB(PDGF BB)对血管平滑肌细胞和心肌细胞中细胞周期素和P2 7蛋白表达量的不同影响。方法 培养的血管平滑肌细胞或乳鼠心肌细胞 ,加入AngⅡ 10 -6 mol/L、PDGF BB 2 0ng/ml后 2 4小时收集细胞 ,用碘化丙啶 (PI)标记细胞DNA ,以确定细胞所处的周期。用细胞周期素 (CyclinD、CyclinE、CyclinA)或P2 7蛋白的单克隆抗体和标记FITC的二抗标记细胞 ,用流式细胞仪测定被激发出的荧光量来测定细胞周期素和P2 7蛋白表达的相对量。结果 AngⅡ除轻度增加心肌细胞CyclinE表达 ( 2 3 9± 4 3对照 8 9± 1 6,P <0 0 1)外 ,对 2种细胞中其他细胞周期素和P2 7蛋白的表达没有明显影响 ,不能促进血管平滑肌细胞和心肌细胞增殖 ;PDGF BB可明显促进 2种细胞中细胞周期素的表达 ,抑制血管平滑肌细胞中P2 7的表达 ( 1 8±1 3、对照 4 8 1± 5 4 ,P <0 0 1) ,但不能抑制心肌细胞P2 7的表达 ( 3 9 4± 5 6、对照 4 4 6± 3 6,P >0 0 5 ) ,因而仅能促进血管平滑肌细胞增殖 ,却不能促进心肌细胞增殖。结论 P2 7蛋白是血管平滑肌细胞和心肌细胞能否进入细胞周期并进行有丝分裂的重要调节因子。

Objective To investigate cell cycle distribution of the vascular smooth muscle cells (VSMC) and cardiac myocytes(CM) and different expressions of cyclins and P27 caused by angiotensin Ⅱ(AngⅡ) and platelet derived growth factor BB (PDGF BB) Methods Cultured VSMCs or CMs were collected at 24 h after stimulation of AngⅡ(10 -6 mol/L) and PDGF BB (20ng/ml) Cell cycle distribution, cyclins and P27 expression were determined with flow cytometer Results AngⅡhad no effect on P27 expression in both VSMCs and CMs It did not cause proliferation of both VSMCs and CMs Although PDGF BB could significantly increase cyclins expression in both VSMCs and CMs, it could only significantly inhibit P27 expression in VSMCs (1 8±1 3 vs 48 1±5 4, P <0 01) and cause VSMC proliferation, and had no effect on P27 expression in CMs(39 4±5 6 vs 44 6±3 6, P >0 05) Conclusion The progression of VSMC and CM through G 1 to S phase might be brought out by the inhibition of P27 during proliferation