钙神经素信号途径在前列腺素F2α诱导乳鼠心肌细胞肥大中的作用

Effects of Ca^(2+)/CaM dependent calcineurin signaling pathway on cardiomyocytes hypertrophy induced by PGF2_α in rats

目的:探讨Ca2+/钙调蛋白(CaM)依赖的钙神经素(CaN)信号途径在前列腺素F2α(PGF2α)诱导心肌细胞肥大中的作用。方法:用PGF2α(1μmol/L,0.1μmol/L,0.01μmol/L,0.001μmol/L)刺激Wistar乳鼠心肌细胞,并用CaN特异性抑制剂环胞素A(CsA)加以干预。以心肌细胞总蛋白含量和心肌细胞面积作为反映心肌肥大的指标,用免疫印迹(Western-blot)测定心肌细胞内CaNα-蛋白表达,用Fura 2/AM为荧光指示剂测定心肌细胞内游离钙浓度([Ca2+]i)。结果:除0.001μmol/L浓度的PGF2α外,1.0μmol/L,0.1μmol/L,0.01μmol/L的PGF2α均可明显提高心肌细胞内蛋白质浓度,而其中0.1μmol/L PGF2α作用最显著,增加了(67.78±11.19)%,并且使乳鼠心肌细胞面积增加了(68.94±1.52)%。0.1μmol/L PGF2α刺激的心肌细胞CaNα-蛋白表达增加和[Ca2+]i提高,并且加入CsA可阻断0.1μmol/L PGF2α诱导的乳鼠心肌细胞肥大效应。结论:PGF2α可能通过Ca2+/CaM-CaN信号途径刺激乳鼠心肌细胞发生肥大。

Objective：To investigate the effects of Ca^2＋/calmodulin （CAM） dependent calcineurin （CAN） signaling pathway on cardiomyocytes hypertrophy induced by Prostaglandin F2α （PGF2α） in rats. Method：Cardiomyocytes of neonatal Wistar rats were cultured with PGF2α in various concentrations （1.0 μmol/L,0.1 μmol/L, 0. 01 μmol/L, 0. 001 μmol/L）. Cardiomyocyte hypertrophy was evaluated by measuring cell area and protein content. The calcineurin inhibitor Cyclosporine A （CsA） was used to prevented cardiac hypertrophy induced by 0. 1 μmol/ L PGF2α. CaN-α protein was assayed by Western-blot. Using Fura 2/AM as a fluorescent indicator, the intracellular free calcium concentration （[Ca^2＋] i） was measured. Result：PGF2α significantly increased the protein content and cardiomyocyte area in three concentrations, includel. 0 μmol/L, 0.1 μmol/L, 0. 01μmol/L PGF2α （P〈0. 05）, except 0. 001 μmol/L （P〈0.05）. and the protein content and cardiomyocyte area were increased most by 0. 1 μmol/L PGF2α, by 49.52 ± 11.52% and 68.94 ± 1.52%, respectively, but which was abolished partly by CsA. [Ca^2＋ ] i was elevated markedly in cardiomyocytes by 0.1 μmol/L PGF2α, as well as CaN-α protein expression. Conclusion ：Cardiomyocyte hypertrophy induced by PGF2α may be mediated through Ca^2＋/CaM-CaN signaling pathway in rats.