肌肽对高糖诱导的心肌成纤维细胞增殖的影响

目的 研究肌肽(carnosine)对高糖环境下大鼠心脏成纤维细胞(cardiac flbroblasts,CFs)增殖的影响及机制.方法 以CFs为研究对象,使用Brdu-酶联免疫吸附试验(enzyme-linked immu-nosorbent assays,ELISA)检测法观察肌肽抑制高糖环境下心肌成纤维细胞DNA的合成;细胞周期的测定采用流式细胞仪法;Western blot法观察不同条件下CFs中CDK2、CyclinE、PCNA、ERK1/2、p-ERK1/2及p21和p27的蛋白表达情况.结果 肌肽能够抑制高糖环境下CFs的DNA合成,通过调节细胞周期和细胞周期的相关蛋白表达来实现这种作用.与高糖组比较,20 mmol/L肌肽组明显抑制了高糖刺激的大鼠CFs中CDK2、CyclinE、PCNA蛋白的表达增加(t CDK2=6.19、t CyclinE=5.7、t PCNA=8.56,P<0.05),差异具有统计学意义;与高糖组比较20 mmol/L肌肽则使p21、p27表达水平增加了(t p21=5.16、t p27=8.558,P<0.05),具有统计学意义;与高糖组比较20 mmol/L的肌肽或20 mol/L的PD-98059(ERK1/2抑制剂)明显抑制了高糖刺激的大CFs中p-ERK1/2的表达增加(t肌肽=5.64、t PD=8.68,P<0.05),差异具有统计学意义.结论 肌肽能够通过ERK1/2 MAPK信号通路抑制高糖环境下心肌成纤维细胞的DNA合成.

Effect of carnosine on cell proliferation in rat cardiac flbroblasts induced by high glucose and its mecha-nism

Objective To study the effect of carnosine on the proliferation of rat cardiac flbroblasts (CFs)induced by high glucose. Methods CFs were used in this experiment. Brdu-enzyme-linked immunosor-bent assays(ELISA)was used to observe CF DNA synthesis induced by high glucose. The cell cycle was deter-mined by flow cytometry. In addition,Western blot method was used to observe the expression level of cell cycle proteins including p21,p27,cyclin E,and CDK2. MAPK pathways related proteins ERK1 / 2 and p-ERK1 / 2 were also determined. Results Carnosine can significantly inhibit DNA synthesis of CFs induced by high glucose,we found that 20 mmol/ L carnosine prevented the increase of cyclin E,CDK2 and PCNA expression(t CDK2 = 6. 19、tCyclin E = 5. 7、t PCNA = 8. 56,P < 0. 05)and counteracted the reduced expression of p27 and p21 induced by high glucose(t p21 = 5. 16、t p27 = 8. 558,P < 0. 05). In addition,ERK1 / 2 signaling took part in the proliferation process and regulated the expression of the cell cycle proteins(t肌肽 = 5. 64、t PD = 8. 68,P < 0. 05). Conclusions Carnosine can inhibit proliferation of CFs by high glucose. The mechanism on carnosine's inhibition could be related to ERK1 / 2MAPK pathways.