TGF-β_1作用后老龄大鼠心肌成纤维细胞p38 MAPK通路和JNK通路的变化

Age-associated changes of p38 MAPK and JNK signal pathways in cardiac fibroblasts treated with transforming growth factor beta 1

目的:探讨转化生长因子β1(TGF-β1)作用后老龄大鼠心肌成纤维细胞丝裂原活化蛋白激酶(p38 MAPK)通路和c-Jun氨基端激酶(JNK)信号通路的变化。方法:提取乳鼠及老龄大鼠心肌成纤维细胞,以TGF-β1(5μg/L)刺激,分为乳鼠PBS对照组(N1组)、乳鼠TGF-β1干预组(N2组)、老龄鼠PBS对照组(A1组)和老龄鼠TGF-β1干预组(A2组)。采用MTT比色法测定细胞增殖;Western blotting检测各组成纤维细胞总p38、phospho-p38、JNK及phospho-JNK水平。结果:TGF-β1刺激后老龄鼠心肌成纤维细胞增殖能力低于乳鼠心肌成纤维细胞。加入TGF-β1后,N2组和A2组的phospho-p38和phospho-JNK分别较N1组和A1组明显升高;N2组与A2组总p38及JNK水平无显著差异;加入TGF-β1后,与N2组相比,A2组phospho-p38及phospho-JNK表达水平显著减弱(P<0.05)。结论:老龄导致心肌成纤维细胞的TGF-β1/p38及TGF-β1/JNK信号通路相关蛋白磷酸化水平受损。

To investigate the effect of aging on p38 mitogen -activated protein kinase （MAPK） and c -Jun N- terminal kinase（JNK） signal pathways in rat cardiac fibroblasts （CFs）. METHODS： Cardiac fibroblasts ob- tained from neonatal and aged rats were cultured and randomly divided into 4 groups： neonatal PBS control group （ N1 group）, neonatal TGF - treatment group （N2 group）, aged PBS control group （A1 group） and aged TGF - treatment group （A2 group）. Proliferation of CFs was detected by MTI coloricmetric assay. The expression levels of total p38 MAPK, JNK, phospho -p38 and phospho -JNK were measured by Western blotting. RESULTS： The proliferative capac- ity of aged CFs was significantly decreased as compared with neonatal CFs after stimulated with TGF -In response to TGF - the expression levels of phospho - p38 and phospho - JNK were significantly increased in N2 group and A2 group as compared with N1 group and A1 group, respectively. The levels of total p38 and nonphosphorylated JNK in N2 group were similar to those in A2 group. Compared with N2 group, the levels of phospho -p38 and phospho -JNK marked- ly decreased in A2 group. CONCLUSION： These data indicate that p38 MAPK and JNK signal pathways are impaired in aged CFs.