细胞周期蛋白D_1基因表达在心肌肥大形成中的时相性变化

Expression of cyclin D_1 gene during the development of myocardial hypertrophy

目的:观察心肌肥大形成过程中细胞周期蛋白D1(cyclinD1)基因表达的时相性变化,并探讨cyclinD1在心肌肥大形成中的作用。方法:采用腹主动脉缩窄法建立大鼠心肌肥大模型,设缩窄手术组及假手术对照组,观察两组大鼠手术后不同时间心脏左心室(含左心室游离壁与室间隔)质量与体质量比、左心室游离壁厚度及心肌细胞横径的变化,以确证模型的稳定建立;其后应用RNA印迹法分析检测cyclinD1基因表达的变化。结果:手术后2周时两组大鼠的心脏左心室质量与体质量比、左心室游离壁厚度以及心肌细胞横径均无显著差别,而缩窄手术组cyclinD1基因mRNA表达显著高于对照组(P<0.05);4周时缩窄组大鼠上述3项病理学检测指标及cyclinD1基因mRNA表达均高于对照组(P<0.05)。结论:在心肌肥大形成过程中cyclinD1基因mRNA表达增加,且早于病理变化出现,提示cyclinD1可能参与了心肌肥大的形成。

Objective: To observe the expression of cyclin D 1 gene during the development of myocardial hypertrophy and investigate the effect of cyclin D 1 on formation of myocardial hypertrophy. Methods: The experimental myocardial hypertrophy rat model was constructed through abdominal aortic banding, and was proved to be efficient by pathologic detection including ratio of left ventricular(LV) mass/body weight, thickness of LV disassociated wall and myocytes width in stenosis and control groups. The mRNA level of cyclin D 1 of rat myocardium was analyzed by Northern blotting. Results: There was significant increase of LV mass/body weight, thickness of LV disassociated wall and myocytes width in stenosis group 4 but not 2 weeks after constriction ( P <0.05). Cyclin D 1 mRNA level increased greatly in stenosis group both 2 and 4 weeks after constriction( P <0.05). Conclusion: Cylin D 1 mRNA level increased significantly during the development of myocardial hypertrophy before pathologic change suggest the possible role of cyclin D 1 in the formation of myocardial hypertrophy.