脂多糖对皮肤成纤维细胞增殖的影响与机制

Effect of Lipopolysaccharide on Proliferation of Skin Fibroblasts and Its Mechanism of Action

目的探讨脂多糖(LPS)对皮肤成纤维细胞增殖的影响及其作用机制。方法将0、10、20、40μg·L-1的LPS分别作用于皮肤成纤维细胞0、24、48、72h,用MTT法检测各浓度LPS作用不同时间后皮肤成纤维细胞的增殖情况。再将最佳生长抑制浓度的LPS作用皮肤成纤维细胞0、20、40、60min,采用Western blot法检测丝裂原活化蛋白激酶(MAPK)信号通路中的关键蛋白ERK、JNK、p38磷酸化与非磷酸化的表达情况。结果 20μg·L-1的LPS在48h时对皮肤成纤维细胞的生长抑制情况最佳,生长率为(24.03±0.31)%。凝胶成像显示磷酸化JNK(p-JNK)的条带随着时间的增加越来越浅,非磷酸化JNK(T-JNK)条带在各个时间的深度基本一致;p-JNK/TJNK比值随着时间的增加而减少(P<0.05),p-ERK/T-ERK与p-P38/T-P38比值各时间点均无明显变化(P>0.05)。结论 LPS可抑制皮肤成纤维细胞的增殖,其可能的作用机制是通过JNK途径刺激皮肤成纤维细胞产生炎性反应。

Objective To investigate the effect of lipopolysaccharide(LPS)on the proliferation of skin fibroblasts and its mechanism of action.Methods The proliferation of skin fibroblasts was detected by MTT assay after treatment with different concentrations of LPS(10,20 and 40μg·L-1)for 24,48 and 72hours.In addition,the expression of phosphorylated and non-phosphorylated ERK,JNK and p38 MAP kinases was measured by Western blot after treatment with the optimal concentration of LPS for 20,40 and 60 minutes.Results The maximal inhibitory effect of LPS on the growth of skin fibroblasts was observed at the concentration of 20μg·L-1 for 48 hours.The inhibition rate was(24.03±0.31)%.Gel imaging showed that the density of phospho-JNK(p-JNK)and the ratio of p-JNK/total JNK(T-JNK)decreased over time(P<0.05).No significant differences in T-JNK expression,phospho-ERK(p-ERK)/total ERK(T-ERK)ratio and phospho-P38(p-P38)/total P38(T-P38)ratio among the different time points(P>0.05).Conclusion LPS inhibits the proliferation of skin fibroblasts through JNK-dependent proinflammatory signaling pathway.