N-乙酰基-丝氨酰-天门冬酰-赖氨酰-脯氨酸对P38分裂原活化蛋白酶通路调节在肺成纤维细胞胶原合成中的作用

Effect of N-acetyl-seryl-aspartyl-lysyl-proline on the collagen synthesis through regulating P38MAPK pathway mediated by TGF-β1 in cultured rat pulmonary fibroblasts

目的：探讨N乙酰基-丝氨酰-天门冬酰-赖氨酰-脯氨酸（AcSDKP）是否通过阻断转化生长因子-β1（TGF-β1）介导的P38分裂原活化蛋白酶（MAPK）途径，进而抑制大鼠肺成纤维细胞增殖与Ⅰ型、Ⅲ型胶原蛋白的表达。方法：培养新生大鼠肺成纤维细胞，分为对照组、TGF-β1刺激组、TGF-β受体阻滞剂组、P38MAPK特异性抑制剂组、AcSDKP干预组。采用MTT法检测细胞增殖，免疫细胞化学法检测磷酸化P38蛋白的定位及表达，免疫印迹法检测TGF-β受体、磷酸化P38MAPK、P38MAPK、c-myc及Ⅰ型、Ⅲ型胶原蛋白的表达。结果：与对照组比较，TGF-β1能够促进细胞增殖，而分别给予LY364947、SB203580和AcSDKP干预后，细胞增殖均受到抑制。与对照组比较，TGF-β1刺激组的TGF-β1受体、磷酸化P38MAPK、c-myc以及Ⅰ型、Ⅲ型胶原蛋白表达上调，当分别给予LY364947、SB203580和AcSDKP干预后，肺成纤维细胞TGF-β1受体、磷酸化P38MAPK、c-myc以及Ⅰ型、Ⅲ型胶原蛋白表达均降低。而各组间比较P38MAPK蛋白表达无明显改变。结论：AcSDKP能够通过阻断TGF-β1介导的P38MAPK信号转导途径，进而抑制肺成纤维细胞增殖和Ⅰ、Ⅲ型胶原蛋白的表达。

Objective： To investigate whether AcSDKP could inhibit proliferation and the expression of type Ⅰ and type Ⅲ collagen in cultured rat pulmonary fibroblasts through blocking P38 MAPK pathway mediated by TGF-β1. Methods： Neonatal rat pulmonary fibroblasts were used in the experiment, and then divided into control group, TGF-β1 stimulated group, TGF- β receptor inhibition treated （LY364947） group, inhibition of P38 MAPK pathway treated （SB203580） group, and AcSDKP treated group. The proliferation of pulmonary fibroblasts was detected by MTT. The location and expression of phospho- P38 MAPK in lung fibroblast were identified by immunocytochemistry. The expressions of TGF-β receptors, phospho-P38 MAPK, P38 MAPK, c-myc and type Ⅰ and type Ⅲ collagen were detected by Western blot. Results： Compared with the control group, TGF-β1 promoted the proliferation of pulmonary {ibroblasts, while LY364947, SB203580 and AcSDKP inhibited the proliferation of pulmonary fibroblasts. Compared with the control group, the expression of TGF-β receptors, phospho-P38 MAPK, c-myc, type Ⅰ and type Ⅲ collagen increased in the TGF-β1 stimulation group, while in LY364947, SB203580 and AcSDKP groups, their expressions all decreased obviously. The expression of P38MAPK had no significant difference among the groups. Conclusion： AcSDKP could block TGF-β1-induced P38 MAPK pathway, and then inhibit the proliferation and the expression of type Ⅰ and type Ⅲ collagen in rat pulmonary fibroblasts.