JNK信号通路介导高糖诱导的大鼠心肌成纤维细胞增殖

 目的 明确c-Jun氨基末端激酶（JNK）信号通路在高糖诱导大鼠心肌成纤维细胞增殖中的作用。方法 提取大鼠原代心肌成纤维细胞，观察不同糖浓度（12、18和25 mmol/L葡萄糖）和不同刺激时间（0、12、24和48 h）对JNK通路的影响。实验分为对照组（5.5 mmol/L葡萄糖）、高糖组（25 mmol/L葡萄糖）、JNK抑制剂SP600125组（25 mmol/L葡萄糖+SP600125 10、20 μmol/L）和高渗组（5.5 mmol/L葡萄糖+19.5 mmol/L甘露醇）培养48 h，应用MTT测定细胞增殖、Weastern blot测定JNK磷酸化水平和增殖细胞核抗原（PCNA）的蛋白表达、RT-PCR检测c-jun基因表达。结果 高糖呈时间和剂量依赖性增加JNK磷酸化水平。与对照组比较，高糖显著地促进了心肌成纤维细胞的增殖（0.44±0.02 vs 0.31±0.02, P<0.01），并上调了c-jun的基因表达和PCNA蛋白水平。 SP600125能够浓度依赖性地抑制高糖诱导的细胞增殖和JNK通路的激活。结论 JNK信号通路部分地介导了高糖诱导的大鼠心肌成纤维细胞增殖。

C-JUN N-terminal kinase pathway mediates high glucose-induced proliferation of cardiac fibroblasts in rats

Objective To determine whether JNK signaling pathway is involved in high glucose (HG)-induced proliferation of cardiac fibroblasts (CFs) in rats. Methods Rat CFs were cultured in DMEM (NG: 5.5 mmol/L D-glucose; HG: 12, 18, 25 mmol/L D-glucose; OSM: 5.5 mmol/L D-glucose + 19.5 mmol/L mannitol) for indicated time periods (0, 12, 24, 48 h). Meanwhile, Rat CFs were cultured in DMEM (25 mmol/L D-glucose) with SP600125 (10, 20 μmol/L), a JNK inhibitor, for 48 h. Proliferation was measured by MTT. The expression of proliferating cell nuclear antigen (PCNA), total JNK and phosphorylation of JNK were detected by Western blot analysis. c-jun mRNA expression was assessed by RT-PCR. Results Treatment of CFs with HG significantly increased phosphorylation of JNK in time- and glucose concentration-dependent manner. Compared with NG group, exposure of CFs to HG (25 mmol/L) significantly promoted the proliferation of CFs (0.44±0.02 vs 0.31±0.02, P<0.01), and upregulated c-jun mRNA expression and PCNA levels. SP600125 significantly suppressed HG-induced the proliferation of CFs and the activity of JNK in a dose-dependent manner. Conclusions HG stimulates the proliferation of CFs partially through JNK pathway activation.