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目的:研究基质金属蛋白酶(MMPs)及其组织抑制剂(TIMP-1)在慢性阻塞性肺病(COPD)大鼠模型气道细胞外基质重塑中的作用及 N-乙酰半胱氨酸(NAC)、蛋白激酶 C 抑制剂 H7及转移生长因子(TGF-β)单抗干预的影响。方法:Wistar 大鼠随机分为(1)对照组;(2)COPD 模型组,采用熏香烟加气管注小量内毒素法复制 COPD 模型;(3)NAC 干预组(NAC 组);(4)H7干预组(H7组);(5)TGF-β单抗干预组。观察各组病理形态学改变;生化法测定支气管肺组织羟脯氨酸含量;免疫组化法和 RT-PCR 法测支气管肺组织 MMP-9、2及 TIMP-1,以及 TGF-βⅠ、Ⅱ受体的表达;SDA-PAGE 明胶酶谱学测定支气管肺组织 MMPs 酶活性。结果:模型组气道壁以Ⅰ型胶原为主的细胞外基质及羟脯氨酸含量较对照组显著增多,NAC 组及 TGF-β单抗组较模型组显著减少,H7组羟脯氨酸含量较模型组显著增多。模型组 MMP-9、2及 TIMP-1,以及 TGF-βⅠ、Ⅱ受体在气道上皮、肺泡巨噬细胞、肺血管内皮细胞等细胞中蛋白和(或)mRNA 表达显著增强,72 kdMMP-2及92 kdMMP-9酶原活性显著增高,三个干预组 MMP-2、9及 TIMP-1的蛋白及 mRNA 表达较模型组显著减弱,72 kdMMP-2及92 kdMMP-9酶原活性显著减低,三个干预组TGF-βⅠ、Ⅱ受体亦较模型组有不同程度减弱。结论:以Ⅰ型胶原为主的细胞外基质显著增生是 COPD 气道重塑的重要病理改变。COPD 气道细胞外基质降解及合成代谢异常活跃与气道细胞外基质重塑密切相关;NAC 可对 MMP-9/TIMP-1的失衡起调节作用,其表达及功能在一定程度上依赖 PKC 信号传导途径。抑制 TGF-β传导通路可能使胶原等细胞外基质降解及合成减少。
AIM: To investigate the roles of matrix metalloproteinases (MMPs) and their tissue inhibitor of metalloproteinase (TIMP-1) in airway extracellular matrix remodeling in chronic obstructive pulmonary disease (COPD) rat model and the effect of NAC (NAC ), Protein kinase C inhibitor H7 and transfer of growth factor (TGF-β) monoclonal antibody intervention. Methods: The Wistar rats were randomly divided into (1) control group, (2) COPD model group, COPD model was made by injecting small amount of lipopolysaccharide (LPS) H7 intervention group (H7 group); (5) TGF-β monoclonal antibody intervention group. The pathological changes of each group were observed. The content of hydroxyproline in bronchial lung tissue was determined by biochemical method. The expressions of MMP-9, 2, TIMP-1 and TGF-βⅠ, Ⅱ in bronchial lung tissue were detected by immunohistochemistry and RT- SDA-PAGE gelatin zymography was used to detect MMPs activity in bronchoalveolar tissue. Results: Compared with the control group, the content of extracellular matrix and hydroxyproline in type I collagen in the airway wall of the model group was significantly increased compared with the control group. The NAC group and the TGF-β monoclonal antibody group were significantly decreased compared with the model group. The hydroxyproline Content than the model group increased significantly. The expressions of MMP-9, 2, TIMP-1, TGF-βⅠ and Ⅱ in the model group were significantly increased in airway epithelium, alveolar macrophages and pulmonary vascular endothelial cells. The expression of 72 kd MMP- 2 and 92 kd MMP-9 were significantly increased, the protein and mRNA expressions of MMP-2, 9 and TIMP-1 in the three intervention groups were significantly weakened compared with the model group, and the activities of 72 kd MMP-2 and 92 kd MMP-9 were significantly reduced , The three intervention groups TGF-β Ⅰ, Ⅱ receptor also than the model group to varying degrees weaken. Conclusion: The significant proliferation of extracellular matrix with type Ⅰ collagen is an important pathological change of airway remodeling in COPD. COPD airway extracellular matrix degradation and abnormal synthesis and metabolism are closely related to airway extracellular matrix remodeling; NAC may play a regulatory role in the imbalance of MMP-9 / TIMP-1, its expression and function to a certain extent dependent on PKC signal Conduction pathway. Inhibition of TGF-β pathway may lead to the degradation of collagen and other extracellular matrix synthesis and decreased.