替米沙坦改善高糖高胰岛素诱导的心肌成纤维细胞增殖及其机制

目的 研究替米沙坦对高糖高胰岛素共同诱导的心肌成纤维细胞增殖的影响及其机制。方法培养Spargue Dawley(SD)大鼠乳鼠心肌成纤维细胞，随机分为对照组（5.5 mmol/L葡萄糖）、高糖高胰岛素组（25 mmol/L葡萄糖+1×10-7 mol/L胰岛素）、细胞外调节蛋白激酶(ERK)抑制剂组（高糖高胰岛素+10 μmol/L PD98059）和替米沙坦组（高糖高胰岛素+10 μmol/L替米沙坦），培养48 h后，CCK8法检测细胞增殖；结晶紫染色法测定细胞数量；［3H］thymidine标记法测定细胞DNA合成；流式细胞仪分析细胞周期；ELISA试剂盒测定上清液中血管紧张素(Ang)Ⅱ、醛固酮（ALD）含量；Western blot测定磷酸化ERK1/2(p-ERK1/2)蛋白表达量。结果与对照组相比，高糖高胰岛素组细胞增殖(1.43±0.12 vs. 0.50±0.10)、细胞计数(1.64±0.03 vs. 1.06±0.02)、DNA合成量(26135.47±324.86 vs. 14528.26±267.18)、S+G2+M百分比〔(19.33±0.12)% vs.(8.56±0.07)%〕、AngⅡ〔(30.58±7.26) pg/ml vs.(18.26±2.64) pg/ml〕与ALD含量〔(19.62±1.25) pg/ml vs.(12.83±1.29) pg/ml〕及p-ERK1/2蛋白表达量明显升高（P<0.05）；与高糖高胰岛素组相比，ERK抑制剂组细胞增殖(0.72±0.06 vs. 1.33±0.12)、细胞计数(1.35±0.01 vs. 1.64±0.03)、DNA合成量(18643.76±192.52 vs. 26135.47±324.86)、S+G2+M百分比〔(12.84±0.36)% vs.(19.33±0.12)%〕、AngⅡ〔(23.17±5.31) pg/ml vs.(30.58±7.26) pg/ml〕与ALD〔(15.27±1.13) pg/ml vs.(19.62±1.25) pg/ml〕含量及p-ERK1/2蛋白表达量明显降低（P<0.05）；与高糖高胰岛素组相比，替米沙坦组细胞增殖(0.94±0.05 vs. 1.33±0.12)、细胞计数(1.49±0.02 vs. 1.64±0.03 )、DNA合成量(21829.35±154.73 vs. 26135.47±324.86)、S+G2+M百分比〔(15.13±0.42)% vs.(19.33±0.12)%、AngⅡ〔(26.84±4.36) pg/ml vs.(30.58±7.26) pg/ml〕与ALD〔(17.81±1.53) pg/ml vs.(19.62±1.25) pg/ml〕含量及p-ERK1/2蛋白表达量明显降低（P<0.05）；ERK抑制剂组与替米沙坦组各指标间没有统计学差异。结论血管紧张素1型受体AT1R阻滞剂替米沙坦通过部分抑制ERK1/2信号通路改善高糖高胰岛素共同诱导的心肌成纤维细胞增殖。

Telmisartan improves high glucose and high insulin-induced proliferation of cardiac fibroblasts and its mechanism

AIM To study the effect of telmisartan on high glucose and high insulin induced-proliferation of cardiac fibroblasts and its mechanism. METHODSCardiac fibroblasts of suckling Spargue Dawley rats were cultured and randomly divided into control group (5.5 mmol/L glucose), high glucose and high insulin group (25 mmol/L glucose+1×10-7 mol/L insulin), extracellular regulated protein kinase (ERK) inhibitor group (high glucose and high insulin+10 μmol/L PD98059) and telmisartan group (high glucose and high insulin+10 mol/L telmisartan). Forty-eight hours after culture, cell proliferation was detected with cell counting kit-8 (CCK8), cell numbers were measured using crystal violet staining and DNA synthesis was measured using ［3H］thymidine marker. Cell cycle was analyzed using flow cytometry, content of angiotensin II (AngII) and aldosterone (ALD) were measured using ELISA. Protein expression of phosphorylated ERK1/2 (p-ERK1/2) was detected using Western blot. RESULTSCompared with those in control group, cell proliferation (1.43±0.12 vs. 0.50±0.10), cell numbers (1.64±0.03 vs. 1.06±0.02), DNA synthesis (26135.47±324.86 vs. 14528.26±267.18), percentage of S+G2+M ［(19.33±0.12) vs.(8.56±0.07)%］ content of AngII ［(30.58±7.26) vs.(18.26±2.64) pg/ml］ and ALD ［(19.62±1.25) vs.(12.83±1.29) pg/ml］ and protein expression of p-ERK1/2 in high glucose and high insulin group all significantly increased (P<0.05). Compared with those in high glucose and high insulin group, cell proliferation (0.72±0.06 vs. 1.33±0.12), cell numbers (1.35±0.01 vs. 1.64±0.03), DNA synthesis (18643.76±192.52 vs. 26135.47±324.86), percentage of S+G2+M ［(12.84±0.36) vs. (19.33±0.12%)］ content of AngII ［(23.17±5.31) vs.(30.58±7.26) pg/ml］ and ALD ［(15.27±1.13) vs.(19.62±1.25 pg/ml］ and protein expression of p-ERK1/2 in ERK inhibitor group decreased significantly (P<0.05). Compared with those in high glucose and high insulin group, cell proliferation (0.94±0.05 vs. 1.33±0.12), cell numbers (1.49±0.02 vs. 1.64±0.03), DNA synthesis (21829.35±154.73 vs. 26135.47±324.86), percentage of S+G2+M ［(15.13±0.42) vs.(19.33±0.12)%］ content of AngII ［(26.84±4.36) vs.(30.58±7.26) pg/ml］ and ALD ［(17.81±1.53) vs.(19.62±1.25) pg/ml］ and protein expression of p-ERK1/2 significantly decreased (P<0.05). No significant difference was found in the above indexes between ERK inhibitor group and telmisartan group. CONCLUSIONAs the inhibitor of AT1 receptor, telmisartan improves high glucose and high insulin-induced proliferation of cardiac fibroblasts partly through inhibiting the ERK1/2 signaling pathway.