【作者】 朱平；

【导师】 何征宇；

【作者基本信息】 上海交通大学 ， 麻醉学（专业学位）， 2016， 硕士

【摘要】 内毒素的主要成分脂多糖(lipopolysaccharide,LPS)为引起急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)和肺纤维化的重要因素。LPS可以通过活化肺成纤维细胞组蛋白去乙酰化酶(histone deacetylase,HDAC)而促进肺成纤维细胞的异常增殖和活化,是肺纤维化发生的关键环节。正丁酸为HDAC抑制剂,本研究旨在观察正丁酸抑制HDAC活化后对LPS刺激肺纤维化进程的影响及其机制,为LPS诱导肺纤维化疾病防治手段的探讨奠定理论基础。第一部分组蛋白去乙酰化酶抑制剂延缓脂多糖诱导肺纤维化作用的评价目的:观察HDAC抑制剂正丁酸延缓LPS诱导肺纤维化过程的作用。方法:将小鼠随机化分为阴性对照组、LPS刺激组和正丁酸预处理+LPS刺激组。制模后2周及4周取小鼠肺组织,检测各组肺组织HDAC活性;用苏木素-伊红(HE)染色和Masson胶原染色镜下观察肺组织炎症和纤维化情况;并测定肺组织羟脯氨酸含量。结果:与阴性对照组相比,腹腔注射LPS后肺组织出现明显的炎症反应和纤维化加重,羟脯氨酸含量增加,伴HDAC活化。与LPS刺激组相比,使用正丁酸可以延缓上述过程。结论:LPS诱导肺组织纤维化过程与肺组织HDAC活化有关。HDAC抑制剂正丁酸能通过抑制HDAC活化,从而延缓由LPS诱导的肺纤维化过程。第二部分组蛋白去乙酰化酶抑制剂延缓脂多糖诱导肺纤维化作用机制的探讨目的:明确HDAC抑制剂正丁酸延缓LPS诱导肺纤维化的机制。方法:将小鼠随机化分为LPS刺激组和正丁酸预处理+LPS刺激组,并设阴性对照组,同样在制模2周及4周后取小鼠肺组织,检测各组肺组织乙酰化组蛋白H3(Acetylated-histone H3,Ace-H3),乙酰化组蛋白H4(Acetylated-histone H4,Ace-H4)和胸腺细胞分化抗原-1(thymocytedifferentiation antigen-1,Thy-1)及各组肺组织Thy-1m RNA表达情况。结果:与阴性对照组相比,腹腔注射LPS后肺组织组蛋白H3、H4乙酰化程度降低,Thy-1基因及蛋白表达量降低。与LPS刺激组相比,使用正丁酸可以延缓上述过程。结论:LPS诱导肺组织纤维化过程与组蛋白H3、H4去乙酰化过程以及Thy-1基因表达抑制相关。HDAC抑制剂正丁酸可以抑制组蛋白H4去乙酰化过程,从而延缓由LPS诱导的Thy-1基因表达抑制及肺纤维化过程。更多还原

【Abstract】 Lipopolysaccharide(LPS),which is the main components of the endotoxin,is important to cause acute respiratory distress syndrome(ARDS)and pulmonary fibrosis.LPS can activate histone deacetylase enzyme(HDAC)of lung fibroblasts,which will cause the abnormal proliferation and activation,and it is critical for pulmonary fibrosis.Butyric acid is the inhibitor of HDAC.We want to observe while the HDAC is inhibited by butyric acid,how LPS affects the lung fibrosis and its mechanism.Part one Evaluating the effect of histone deacetylase inhibitor on delaying Lipopolysaccharide-induced Pulmonary FibrosisObjective:To evaluate the delay effect of butyric acid,which is the inhibitor of histone deacetylase(HDAC),on lipopolysaccharide(LPS)-induced pulmonary fibrosis.Methods: Mice were randomly divided into 3 groups: Control Group;LPS challenge Group;Butyricacid preconditioning and LPS challenge Group.We take the lung tissue 2 weeks and 4 weeks later and test the HDAC activity;stained With hematoxylin-eosin(HE)staining and Masson staining of collagen to Observe the lung tissue inflammation and fibrosis,and to measure the lung Tissue hydroxyproline content.Results: Compared to Control Group,the degree of lung inflammation and fibrosis were aggravated after LPS challenge,with increased hydroxyproline Content and increased HDAC activity,which could be delayed by butyric acid precondition.Conclusion: LPS-induced pulmonary fibrosis was relevant to activation of HDAC.Butyric acid,inhibitor of HDAC,could inhibit LPS-induced pulmonary fibrosis by delaying the activation of HDAC.Part two Mechanism of action of histone deacetylase inhibitor on delaying Lipopolysaccharide-induced Pulmonary FibrosisObjective: To determine the mechanism of how butyric acid,inhibitor of HDAC,delay LPS-induced pulmonary fibrosis.Methods: Mice were randomly divided into 3 groups: LPS stimulation group and butyric acid pretreatment + LPS stimulation group and control group.We also take the lung tissue 2 weeks and 4 weeks later and test the Acetylated-histone H3(Ace-H3),Acetylated-histone H4(Ace-H4),thymocyte differentiation antigen-1(Thy-1)and the expression of Thy-1m RNAResults: Compared with the control group,acetylation of lung histone H3,H4 was reduced after intraperitoneal injection of LPS,Thy-1 gene and protein expression was reduced.Butyric acid can delay the process.Conclusion: LPS-induced lung fibrosis is associated with histone H3,H4 deacetylation and inhibition of Thy-1 gene expression.Butyric acid,inhibitor of HDAC,can inhibit the deacetylation of histone H4,thereby delaying the LPS-induced gene expression of Thy-1 and the pulmonary fibrosis.更多还原