中文摘要：

目的 观察转化生长因子-β （TGF-β）Ⅰ型、Ⅱ型受体、P38丝裂原活化蛋白激酶（P38MAPK）和Ⅰ型、Ⅲ型胶原在矽肺大鼠和肺成纤维细胞的分布与表达,探讨N-乙酰基-丝氨酰-天门冬酰-赖氨酰-脯氨酸（AcSDKP）对TGF-β受体介导的P38MAPK信号转导通路调节与其抗矽肺纤维化作用的关系.方法 非暴露式支气管内灌注法制作大鼠矽肺模型,分为对照组,矽肺模型组和AcSDKP治疗组（每组10只）.培养新生大鼠肺成纤维细胞,分为对照组、TGF-β1刺激组、受体阻断剂组、P38MAPK特异性抑制剂干预组和AcSDKP干预组.免疫组化法、免疫印迹法（Western-blot）检测TGF-βⅠ型和Ⅱ型受体、P38 MAPK蛋白以及Ⅰ型、Ⅲ型胶原蛋白的表达.用实时定量荧光聚合酶链式反应（real-time PCR）法检测TGF-β Ⅰ型和Ⅱ型受体mRNA的表达.用激光扫描共聚焦显微镜法检测磷酸化P38在肺成纤维细胞内分布与核转位的情况.结果 在动物模型中,AcSDKP治疗组大鼠肺组织内TGF-β Ⅰ型受体、Ⅱ型受体和磷酸化P38 MAPK蛋白的表达分别是矽肺模型组的86.12％、41.01％和42.63％;AcSDKP治疗组Ⅰ型、Ⅲ型胶原的表达,分别是矽肺模型组的89.05％和52.71％,差异均有统计学意义（P＜0.05）.在培养的肺成纤维细胞实验中,AcSDKP干预组TGF-β1诱导刺激的TGF-β Ⅰ型受体、Ⅱ型受体mRNA的表达分别是TGF-β1刺激组的42.26％和54.33％;TGF-β Ⅰ型受体、Ⅱ型受体和磷酸化P38 MAPK蛋白的表达分别是TGF-β1刺激组的58.14％、51.40％和45.6％;AcSDKP干预组磷酸化P38MAPK蛋白由胞质向胞核的转位,核浆比值减少,为TGF-[β1刺激组的68.60％;Ⅰ型、Ⅲ型胶原蛋白表达降低,分别是TGF-β刺激组的58.04％和44.74％,差异均有统计学意义（P＜0.05）.结论 AcSDKP能够抑制TGF-β受体介导的P38 MAPK信号转导途径,从而抑制胶原蛋白的表达,进而发挥其抗矽肺纤维化的作用.

英文摘要：

Objective To investigate the distribution and expression of transforming growth factor beta （TGF-β） receptors Ⅰ and Ⅱ,p38 mitogen-activated protein kinase （p38 MAPK）,and type Ⅰ and type Ⅲ collagen in the lungs of rats with silicosis and cultured pulmonary fibroblasts,and to investigate the relationship of the anti-fibrosis effect of N-acetyl-seryl-aspartyl-lysyl-proline （AcSDKP） with its inhibition of TGF-3 receptor-mediated p38 MAPK pathway activity.Methods Rats were randomly divided into control group,silicosis model group,and AcSDKP treatment group （n=10 for each group）.For the model group and AcSDKP treatment group,rats were intratracheally instilled with silica to establish a silicosis model.Cultured pulmonary fibroblasts from neonatal rats were divided into control group,TGF-~ stimulation group,TGF-β receptor inhibition group,p38 MAPK pathway inhibition group,and AcSDKP treatment group.The protein expression of TGF-β receptors Ⅰ and Ⅱ,p38 MAPK,and type Ⅰ and type Ⅲ collagen were determined by immunohistochemistry and Western blot.The mRNA expression of TGF-β receptors Ⅰ and Ⅱ were determined by real-time PCR.The distribution and nuclear translocation of phospho-p38 MAPK in cultured fibroblasts were determined by laser scanner confocal microscopy.Results In the AcSDKP treatment group,AcSDKP reduced the expression of TGF-β receptors Ⅰ and Ⅱ,phospho-p38 MAPK,and type Ⅰ and type Ⅲ collagen to 86.12％,41.01％,42.63％,89.05％,and 52.71％,respectively,of those of the silicosis model group （P＜0.05）.In cultured fibroblasts,AcSDKP reduced the mRNA expression of TGF-β receptors Ⅰ and Ⅱ to 42.26％ and 54.33％,respectively,of those of the TGF-β1 stimulation group; the protein expression of TGF-β receptors Ⅰ and Ⅱ,phospho-p38 MAPK,and type 1 and type Ⅲ collagen was reduced to 58.14％,51.40％,45.6％,58.04％,and 44.74％,respectively,of those of the TGF-β1 stimulation group.The phospho-p38 MAPK translocation from plasma to the nucleus was also