PTS2对LPS引起的RAW264.7细胞中iNOS蛋白表达的影响及其机理研究
发布时间：2019-07-05 11:45
【摘要】： LPS是革兰氏阴性菌细胞壁的主要成分。用LPS处理细胞或动物能够引起类似于脓毒性休克的炎症反应。脓毒性休克能引起严重的循环系统障碍,致死率高达30—90%且治疗无效。促炎细胞主要是指活化的巨噬细胞,它们在炎症过程中能够产生大量的细胞因子和促炎分子,包括血小板活化因子、前列腺素、酶和类似NO的自由基分子等。这些分子能够在细胞和分子水平上引起脓毒症的病理生理反应。在大多数炎症介质中,NO是内毒素血症和炎症反应的重要调节分子。NO能够与超氧阴离子(O~(2-))迅速反应生成过氧化亚硝酸盐(ONOO~-)。过氧化亚硝酸盐(ONOO~-)能够导致DNA破坏、低密度脂蛋白(LDL)氧化并使其酪氨酸发生硝化作用。NO在炎症发生的各个阶段都能起到调节作用,尤其是在炎症发生早期炎症细胞迁移到炎症部位的过程中。在炎症发生过程中,过量的NO主要由诱导型一氧化氮合酶(iNOS)催化产生。LPS刺激巨噬细胞能够上调胞内iNOS的蛋白水平。许多能够抑制iNOS表达或iNOS酶活的化合物都具有抗炎活性。在包括巨噬细胞在内的多种细胞中,LPS能够刺激Toll样受体4(TLR-4)从而活化NF-κB。NF-κB作为重要的转录因子参与iNOS的基因表达。另外一个参与LPS刺激下iNOS表达调控的转录因子STAT1(the signal transducerand activator of transcription 1)是通过JAK-STAT通路被活化。LPS也可以通过活化巨噬细胞内MAPKs信号通路来增强iNOS基因表达。 PTS2(2,2'-二吡啶N-氧化物二硫)属于巯氧吡啶的衍生物(CASnumber:3696-28-4),通常被用于抗细菌和抗真菌药物。PTO(Pyrithione)是PTS2的单体,能够抑制真菌、酵母菌、霉菌、细菌的生长,被广泛应用于美容及洗发用品的添加成分。之前,我们的研究证明了PTS2能够通过活化MAPKs信号通路来诱导HeLa细胞凋亡。最近我们发现,在鼠巨噬细胞RAW264.7细胞中PTS2能够剂量依赖性地抑制LPS刺激下的iNOS的蛋白表达及NO的释放。在其分子机制的研究过程中,我们发现PTS2能够降低LPS刺激下转录因子STAT1的磷酸化活化而不影响MAPKs和NF-κB信号通路。所以我们得出结论,在鼠巨噬细胞RAW264.7细胞中PTS2能够通过影响LPS刺激下STAT1的激活从而抑制iNOS蛋白表达及NO释放,发挥抗炎作用。
[Abstract]:LPS is the main component of the cell wall of Gram-negative bacteria. LPS treatment of cells or animals can cause inflammatory reactions similar to septic shock. Septic shock can cause serious circulatory system disorders, the fatality rate is as high as 30% and 90%, and the treatment is ineffective. Pro-inflammatory cells mainly refer to activated macrophages, which can produce a large number of cytokines and pro-inflammatory molecules, including platelet activating factor, prostaglandin, enzyme and NO-like free radical molecules. These molecules can cause pathophysiological responses to sepsis at the cellular and molecular levels. In most inflammatory mediators, NO is an important regulator of endotoxemia and inflammatory response. No can react rapidly with hyperoxia anion (O2 -) to form nitrous peroxide (ONOO~-). Nitrate peroxide (ONOO~-) can lead to the destruction of DNA, the oxidation of low density lipoprotein (LDL) and the nitrification of its tyrosine. No can play a regulatory role in all stages of inflammation, especially in the process of migration of inflammatory cells to inflammatory sites in the early stage of inflammation. In the process of inflammation, excessive NO is mainly catalyzed by (iNOS), which stimulates macrophages to up-regulate the protein level of intracellular iNOS. Many compounds that can inhibit iNOS expression or iNOS enzyme activity have anti-inflammatory activity. In a variety of cells, including macrophages, LPS can stimulate Toll-like receptor 4 (TLR-4) and activate NF- 魏 B.NF-魏 B as an important transcription factor to participate in the gene expression of iNOS. Another transcription factor STAT1 (the signal transducerand activator of transcription 1, which is involved in the regulation of iNOS expression stimulated by LPS, is activated through JAK-STAT pathway. LPs can also enhance iNOS gene expression by activating MAPKs signaling pathway in macrophages. PTS2 (2, 2 dipyridine N-oxide disulfide) is a derivative of mercaptopyridine (CASnumber:3696-28-4), which is usually used as an antibacterial and antifungal drug. PTO (Pyrithione) is a monomer of PTS2, which can inhibit the growth of fungi, yeast, mold and bacteria, and is widely used in beauty and shampoo products. Previous studies have shown that PTS2 can induce apoptosis of HeLa cells by activating MAPKs signaling pathway. Recently, we have found that PTS2 can inhibit the protein expression and NO release of iNOS stimulated by LPS in mouse macrophage RAW264.7 cells in a dose-dependent manner. In the course of studying its molecular mechanism, we found that PTS2 could decrease the phosphorylation and activation of transcription factor STAT1 stimulated by LPS without affecting MAPKs and NF- kappa B signaling pathways. Therefore, we concluded that PTS2 in mouse macrophage RAW264.7 cells can inhibit the expression of iNOS protein and NO release by affecting the activation of STAT1 stimulated by LPS, and play an anti-inflammatory role.
【学位授予单位】：南京师范大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R378
本文编号：2510497
[Abstract]:LPS is the main component of the cell wall of Gram-negative bacteria. LPS treatment of cells or animals can cause inflammatory reactions similar to septic shock. Septic shock can cause serious circulatory system disorders, the fatality rate is as high as 30% and 90%, and the treatment is ineffective. Pro-inflammatory cells mainly refer to activated macrophages, which can produce a large number of cytokines and pro-inflammatory molecules, including platelet activating factor, prostaglandin, enzyme and NO-like free radical molecules. These molecules can cause pathophysiological responses to sepsis at the cellular and molecular levels. In most inflammatory mediators, NO is an important regulator of endotoxemia and inflammatory response. No can react rapidly with hyperoxia anion (O2 -) to form nitrous peroxide (ONOO~-). Nitrate peroxide (ONOO~-) can lead to the destruction of DNA, the oxidation of low density lipoprotein (LDL) and the nitrification of its tyrosine. No can play a regulatory role in all stages of inflammation, especially in the process of migration of inflammatory cells to inflammatory sites in the early stage of inflammation. In the process of inflammation, excessive NO is mainly catalyzed by (iNOS), which stimulates macrophages to up-regulate the protein level of intracellular iNOS. Many compounds that can inhibit iNOS expression or iNOS enzyme activity have anti-inflammatory activity. In a variety of cells, including macrophages, LPS can stimulate Toll-like receptor 4 (TLR-4) and activate NF- 魏 B.NF-魏 B as an important transcription factor to participate in the gene expression of iNOS. Another transcription factor STAT1 (the signal transducerand activator of transcription 1, which is involved in the regulation of iNOS expression stimulated by LPS, is activated through JAK-STAT pathway. LPs can also enhance iNOS gene expression by activating MAPKs signaling pathway in macrophages. PTS2 (2, 2 dipyridine N-oxide disulfide) is a derivative of mercaptopyridine (CASnumber:3696-28-4), which is usually used as an antibacterial and antifungal drug. PTO (Pyrithione) is a monomer of PTS2, which can inhibit the growth of fungi, yeast, mold and bacteria, and is widely used in beauty and shampoo products. Previous studies have shown that PTS2 can induce apoptosis of HeLa cells by activating MAPKs signaling pathway. Recently, we have found that PTS2 can inhibit the protein expression and NO release of iNOS stimulated by LPS in mouse macrophage RAW264.7 cells in a dose-dependent manner. In the course of studying its molecular mechanism, we found that PTS2 could decrease the phosphorylation and activation of transcription factor STAT1 stimulated by LPS without affecting MAPKs and NF- kappa B signaling pathways. Therefore, we concluded that PTS2 in mouse macrophage RAW264.7 cells can inhibit the expression of iNOS protein and NO release by affecting the activation of STAT1 stimulated by LPS, and play an anti-inflammatory role.
【学位授予单位】：南京师范大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R378
【引证文献】
相关硕士学位论文 前1条
1 肖楠;乙酸乙酯抑制小鼠实验性急性肝衰竭及其作用机制的研究[D];河北大学;2011年
，本文编号：2510497
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