硫化氢通过p38MAPK信号通路对肝纤维化大鼠肝细胞增殖、凋亡的影响

目的:探讨硫化氢(hydrogen sulfide,H2S)对肝纤维化大鼠肝细胞增殖、凋亡的调节作用以及P-p38丝裂原活化蛋白激酶(p38mitogen-activated protein kinase,p38MAPK)蛋白的表达的影响.方法:用四氯化碳诱导肝纤维化SD大鼠模型,将提取的肝纤维化大鼠肝细胞分组:对照组、H2S组(对照组基础上加H2S的供体N a H S至最适浓度)、S B组(对照组基础上加SB203580至最适浓度)、SB+H2S组(对照组基础上加Na HS、SB203580至最适浓度).M T T法检测N a H S及S B203580对肝纤维化大鼠肝细胞的增殖、增殖抑制率的影响;Annexin V-FITC/PI双染流式细胞术检测肝纤维化大鼠肝细胞凋亡率;Western blot技术检测P-p38MAPK蛋白在各组中的表达水平.结果:与对照组相比,低浓度H2S(50μmol/L)促进肝纤维化大鼠肝细胞增殖明显(P=0.000),对肝纤维化大鼠肝细胞凋亡无影响;SB203580可抑制肝纤维化大鼠肝细胞的增殖,伴随药物浓度的升高细胞存活率降低(P=0.000),并诱导肝纤维化大鼠肝细胞凋亡(P=0.000);P-p38MAPK蛋白在各组中均有表达,H2S组表达水平高于对照组(P=0.000),SB组、SB+H2S组与对照组、H2S组相比,P-p38MAPK蛋白的表达量均减少(均P=0.000).结论:低浓度H2S对肝纤维化大鼠肝细胞凋亡无诱导作用,但能通过激活p38MAPK信号转导通路促进其细胞增殖.     

p38MAPK信号通路的抑制减轻缺氧复氧环境下心肌细胞凋亡

目的研究p38丝裂原活化蛋白激酶(p38MAPK)信号通路抑制剂对缺氧复氧诱导的心肌细胞凋亡的影响。方法心肌细胞H9C2分为对照组(Con组)、缺氧复氧组(H/R组)、p38MAPK信号通路抑制剂SB203580组(SB203580组),Con组细胞正常培养,H/R组、SB203580组进行缺氧复氧处理,SB203580组细胞在缺氧前用p38MAPK信号通路抑制剂SB203580预处理24 h。噻唑蓝(MTT)检测细胞存活情况,流式细胞术检测细胞凋亡,二硝基苯肼显色法检测上清中乳酸脱氢酶(LDH)含量,用硫代巴比妥酸比色法检测细胞中丙二醛(MDA)含量,用黄嘌呤氧化法检测细胞中超氧化物歧化酶(SOD)含量,二氯二氢荧光素-乙酰乙酸酯(DCFH-DA)法检测细胞中活性氧(ROS)含量,Western blot检测细胞中p38MAPK、磷酸化p38MAPK(p-p38MAPK)、活化的含半胱氨酸的天冬氨酸蛋白水解酶3(Cleaved Caspase-3)蛋白表达。结果 H/R组、SB203580组细胞存活率低于Con组,凋亡率高于Con组,细胞中MDA、ROS含量高于Con组,培养液上清中LDH高于Con组,细胞中SOD含量低于Con组,细胞中p-p38MAPK、Cleaved Caspase-3蛋白水平高于Con组。SB203580组细胞存活率高于H/R组,凋亡率低于H/R组,细胞中MDA、ROS含量低于H/R组,培养液上清中LDH低于H/R组,细胞中SOD含量高于H/R组,细胞中p-p38MAPK、Cleaved Caspase-3蛋白水平低于H/R组。结论 p38MAPK信号通路抑制剂能够减轻缺氧复氧环境下心肌细胞凋亡和氧化损伤。     

阿托伐他汀抑制同型半胱氨酸诱导的内皮细胞凋亡涉及NADPH氧化酶及p38MAPK途径

目的观察阿托伐他汀对同型半胱氨酸（Hcy）诱导的人脐静脉内皮细胞凋亡及活性氧的影响,并探讨其作用机制。方法Hcy单独或联合阿托伐他汀、N-乙酰半胱氨酸（NAC）、还原型辅酶Ⅱ（NADPH）氧化酶抑制剂（DPI）或p38促细胞分裂剂激活性蛋白激酶（p38MAPK）阻断剂（SB203580）处理人脐静脉内皮细胞后,检测细胞凋亡率,活性氧水平,NADPH氧化酶活性,caspase-3 mRNA的表达和p-p38MAPK的表达。结果阿托伐他汀明显抑制Hcy诱导的人脐静脉内皮细胞凋亡及活性氧的产生,并能拮抗Hcy诱导的NADPH氧化酶的激活,p38MAPK蛋白的磷酸化及caspase-3 mRNA表达的增加。NAC、DPI、SB203580可产生相同的作用。结论阿托伐他汀可能通过抑制NADPH氧化酶的激活,p38MAPK磷酸化途径抑制Hcy诱导的人脐静脉内皮细胞活性氧的产生和细胞凋亡。     

硫化氢在外源性SB203580预处理人卵巢癌SKOV3细胞增殖中的作用

目的探讨硫化氢(H2S)供体硫氢化钠(Na HS)对人卵巢癌SKOV3细胞增殖的影响及可能机制。方法体外培养SKOV3细胞,随机分为正常对照组、Na HS组、SB203580组、Na HS+SB203580组,采用四甲基偶氮唑蓝(MTT)法检测各组SKOV3细胞增殖,流式细胞术检测各组SKOV3细胞周期分布,Western印迹检测各组SKOV3细胞中P-p38MAPK蛋白表达。结果与正常对照组比较,Na HS组SKOV3细胞增殖明显增加,G1期细胞明显减少,S期细胞明显增加,且p-p38MAPK表达明显增加(均P<0.01);SB203580组、Na HS+SB203580组SKOV3细胞增殖均明显减少,G1期细胞均明显增加,S期细胞均明显减少,且p-p38MAPK表达均明显降低(均P<0.01)。而与Na HS组比较,SB203580组、Na HS+SB203580组SKOV3细胞增殖均明显减少,G1期细胞均明显增加,S期细胞均明显减少,且p-p38MAPK表达均明显降低(均P<0.01);与SB203580组比较,Na HS+SB203580组SKOV3细胞的增殖明显增加,G1期细胞明显减少,S期细胞明显增加,且p-p38MAPK表达明显增加(均P<0.01)。结论 H2S可能通过活化p38MAPK信号通路促进SKOV3细胞增殖。     

硫化氢在p38MAPK信号通路对大鼠肝星状细胞凋亡中的作用

目的探讨硫化氢(H2S)在p38MAPK信号通路对大鼠肝星状细胞(hepatic stellate cell,HSC)凋亡中的作用及磷酸化P38、Caspase-3蛋白表达的变化。方法实验设对照组(HSC加含10%胎牛血清的DMEM培养液)、二甲基亚砜(DMSO)组(对照组基础上加DMSO,使其终浓度为0.1%)、NaHS组(对照组基础上加NaHS,使其终浓度为50μmol/L)、SB组(DMSO组基础上加SB203580,使其终浓度为75μmol/L)、SB加NaHS(SB+NaHS)组;采用Hoechst荧光染色检测细胞凋亡;Western blotting法检测磷酸化p38MAPK表达及Caspase-3蛋白表达水平。结果与对照组比较,SB组和SB+NaHS组HSC-T6的凋亡率增加(P0.05),NaHS组p38MAPK磷酸化水平及Caspase-3表达均明显增高(P0.01);与NaHS组比较,SB组和SB+NaHS组细胞凋亡率增加明显(P0.01),p38MAPK磷酸化水平表达降低(P0.01);SB+NaHS组较SB组Caspase-3蛋白表达升高(P0.05)。结论 p38MAPK及Caspase-3在H2S刺激的HSC-T6中表达增强,H2S能促使SB203580诱导的HSC-T6细胞凋亡,其作用机制可能与活化p38MAPK的磷酸化途径,进而激活Caspase-3的表达有关。     

p38 MAPK信号转导通路参与NO诱导兔关节软骨细胞凋亡

目的探讨p38 MAPK信号转导通路在软骨细胞凋亡中的作用。方法体外培养兔关节软骨细胞,一氧化氮(NO)供体NOC-18和p38 MAPK抑制剂SB203580作用于细胞24 h,用AnnexinV-FITC/PI流式细胞术检测软骨细胞凋亡率,W estern b lot测定p38、磷酸化p38蛋白的表达水平。结果与对照组比较,SB203580显著降低了NOC-18诱导的软骨细胞凋亡率(P<0.05);NOC-18以浓度依赖的方式促进p38 MAPK的磷酸化,而SB203580能抑制其磷酸化(P<0.05)。结论p38 MAPK通路参与了NO诱导的兔关节软骨细胞凋亡的信号转导。     

姜黄素对脂质运载蛋白2诱导人脐静脉内皮细胞损伤的影响

目的研究姜黄素对脂质运载蛋白2(LCN-2)诱导人脐静脉内皮细胞(HUVEC)损伤的保护作用及与p38 MAPK通路的关系。方法以LCN-2不同质量浓度(0,5,10,20μmol/L)及不同时间(0,24,48,72 h)作用HUVEC,CCK-8法测细胞增殖,流式细胞仪测细胞凋亡,ELISA测细胞上清液中单核细胞趋化蛋白1(MCP-1)及白细胞介素6(IL-6)含量,比色法测乳酸脱氢酶(LDH)活性,Western blot测HUVEC中p-p38 MAPK、Bax、Bcl-2蛋白表达;分别加入10μmol/L姜黄素和25μmol/L SB203580观察姜黄素的干预作用。结果与对照组比较,LCN-2可显著抑制HUVEC增殖,上调HUVEC内Bax/Bcl-2蛋白比率而促进细胞凋亡,诱导HUVEC分泌MCP-1及IL-6,增加LDH活性(P0.05);与LCN-2组比较,姜黄素及SB203580均可显著减轻LCN-2诱导的HUVEC增殖抑制,下调Bax/Bcl-2蛋白比率而抑制HUVEC凋亡,减少LCN-2诱导的HUVEC分泌MCP-1及IL-6,降低LDH活性(P0.05)。结论姜黄素可通过抑制p38 MAPK通路,减轻LCN-2诱导的HUVEC损伤。     

软脂酸通过丝裂原活化蛋白激酶通路促进血管内皮细胞凋亡

目的探讨软脂酸(PA)诱导的血管内皮细胞凋亡中丝裂原活化蛋白激酶(MAPK)通路的作用。方法将人脐静脉内皮细胞(HUVEC)分对照组、PA组、MAPK通路干预组[分别先用p38抑制剂SB203580、氨基末端激酶(JNK)抑制剂PD98059、细胞外信号调节激酶(ERK)抑制剂SP600125干预]再分为PA+SB组、PA+PD组、PA+SP组。流式细胞仪检测细胞凋亡率;Western blot法检测caspase-3、磷酸化p38、JNK和ERK1/2表达水平;分光光度法检测caspase-3的活性。结果与对照组比较,PA组、PA+SB组、PA+PD组、PA+SP组HUVEC凋亡及caspase-3表达和活性明显增加,PA组磷酸化p38MAPK表达明显增加(P<0.05)。与PA组比较,PA+SB组HUVEC细胞凋亡率、caspase-3表达和活性明显降低(P<0.05);而PA+PD组和PA+SP组HUVEC凋亡率、caspase-3表达和活性无明显变化(P>0.05)。结论 PA通过p38MAPK通路促进内皮细胞凋亡。     

葛根素调控p38信号通路对H_2O_2诱导心肌细胞凋亡的影响

目的探讨葛根素调控p38信号通路对H_2O_2诱导心肌细胞凋亡的影响。方法葛根素处理大鼠H9c2心肌细胞,分为对照组(细胞无特殊处理)、H_2O_2组(200μmol/L H_2O_2干预细胞)和葛根素+H_2O_2组(250μmol/L葛根素和200μmol/L H_2O_2干预细胞),SB203580作为p38信号通路抑制剂,各组细胞处理24 h,通过流式细胞仪检测各组凋亡率;Western印迹检测活化的含半胱氨酸的天冬氨酸蛋白水解酶3(酶切caspase3)、p53、p-p38的蛋白表达。结果与对照组比较,H_2O_2组细胞凋亡率显著升高,酶切caspase3、p53、p-p38蛋白表达均显著升高(P0.05);与H_2O_2组比较,葛根素+H_2O_2组凋亡率显著降低,酶切caspase3、p53、p-p38蛋白表达均显著降低(P0.05);与葛根素+H_2O_2组比较,葛根素+H_2O_2+SB203580组细胞凋亡率显著降低,酶切caspase3、p53、p-p38蛋白表达均显著降低(P0.05)。结论葛根素可通过抑制p38信号通路及下调酶切caspase3和p53表达降低H_2O_2诱导的心肌细胞凋亡。     

在Fas诱导Bel-7402细胞凋亡中p38MAPK调节Bcl-2的表达

目的:探讨p38MPAK是否参与Fas和AD诱导Bel-7402细胞的凋亡过程,以及p38MPAK和bcl-2的关系,进一步揭示p38MAPK的凋亡途径.方法:在Fas和AD作用24h后,用MTT法检测Bel-7402细胞的活力,用Western-blot和RT- PCR法检测p38MAPK,p-p38MAPK和Bcl-2 expression,用免疫荧光法对p-p38MAPK进行细胞定位.结果:随着Fas浓度的增加,Bel-7402细胞的活力明显抑制,p38MAPK和p-p38MAPK表达明显增高(P<0.01),且p-p38MAPK由胞质易位到胞核.Bcl-2的表达明显降低(P<0.01),并且这种降低趋势被p38MAPK抑制剂SB203580所阻止.结论:p38MAPK参与Fas诱导的凋亡途径,以磷酸化形式激活后抑制Bcl一2的表达,进而促进细胞凋亡.     

p38丝裂原活化蛋白激酶抑制剂减少大鼠肝脏炎症细胞因子的表达

目的 观察p38丝裂原活化蛋白激酶(MAPK)抑制剂SB203580阻断p36 MAPK信号通路,减少脑死亡大鼠肝脏促炎细胞因子表达的作用.方法 雄性Wistar大鼠30只,体质量180～200 g,随机分3组,每组10只.脑死亡组:诱导大鼠及死亡;脑死亡+SB203580组:大鼠脑死亡诱导成功后,经阴茎背静脉注射SB203580(10 mg/kg);两组大鼠脑死亡诱导成功,行人工呼吸6 h后,若平均动脉压大于80 mm Hg(1 mm Hg=0.133 kPa),则为脑死亡供体,获取肝脏待检.对照组:正常大鼠麻醉后取肝脏待检.逆转录-聚合酶链反应检测肝脏肿瘤坏死因子(TNF)α和白细胞介素(IL)-1β的mRNA表达,Western blot检测肝脏TNF α和IL-1 β的蛋白质表达以及磷酸化p38 MAPK的表达.多个样本间比较行One-Way ANOVA分析,SNK法行两两样本间比较.结果 脑死亡组大鼠肝脏出现p38 MAPK磷酸化,磷酸化p38 MAPK的相对表达量比对照组明显增加(0.190±0.004比0.001±0.002),差异有统计学意义(q=172.53,P＜0.01);肝脏TNF α的mRNA和蛋白质表达量分别为0.670±0.012和0.240±0.003,较对照组(分别为0.130±0.013和0.001±0.002)明显增加(q值分别为123.99和243.09,P值均＜0.01);肝脏IL-1 β的mRNA和蛋白质表达量分别为0.560±0.009和0.190±0.003,较对照组(分别为0.160±0.010和0.001±0.002)明显增加(q值分别为135.35和192.23,P值均＜0.01).脑死亡SB203580组大鼠肝脏p38 MAPK磷酸化下降,磷酸化p38 MAPK的表达量(0.120±0.004)比脑死亡组明显下降(q=63.90,P＜0.05),但仍明显高于对照组(q=108.63,P＜0.01);肝脏TNF α的mRNA和蛋白质表达量分别为0.430±0.016和0.180±0.004,较脑死亡组明显下降(q值分别为55.11和61.03,P值均＜0.01),但仍高于对照组(q值分别为68.89和182.06,P值均＜0.01);肝脏IL-1β的mRNA和蛋白质表达量分别为0.270±0.009和0.140±0.004,较脑死亡组明显下降(q值分别为98.13和50.85,P值均＜0.01),但仍高于对照组(q值分别为37.22和141.38,P值均＜0.01).结论 SB203580能抑制p38 MAPK的磷酸化,阻断p38 MAPK信号通路,减少脑死亡大鼠肝脏促炎细胞因子表达,降低肝脏免疫原性.     

Src family kinases and nitric oxide production are required for hepatocyte growth factor-stimulated endothelial cell growth

Hepatocyte growth factor (HGF) is a potent mitogen for vascular endothelial cells (EC); however, signal transduction pathways for HGF-stimulated EC growth remain unclear. In the present study we investigated the role of Src family kinases and nitric oxide (NO) in HGF-stimulated EC growth. Human umbilical vein endothelial cells (HUVEC) were stimulated with HGF and NO was measured by an NOx analyzing HPLC system. Activation of ERK1/2 and p38 MAPK was assessed by Western blot. NO production in HUVEC increased 1.8-fold by HGF. A Src family kinases inhibitor PP1 inhibited HGF-stimulated NO production by 71%. HUVEC growth increased 1.9-fold in cell number by HGF. PP1 and Nitro-L-arginine methylester (L-NAME) inhibited HGF-stimulated HUVEC growth by 51 and by 71%. ERK1/2 and p38 MAPK were phosphorylated by HGF and a MEK inhibitor PD98059 and a p38 MAPK inhibitor SB203580 inhibited HGF-stimulated HUVEC growth by 66% and by 58%; however, HGF-induced phosphorylation of ERK1/2 and p38 MAPK was not inhibited by L-NAME, indicating that NO is not an upstream activator of ERK1/2 and p38 MAPK. These findings demonstrated that Src family kinases regulate HGF-stimulated NO production in HUVEC and that HGF stimulates HUVEC growth through NO-dependent and NO-independent pathways.     

Cellular events during arthritis-induced hyperalgesia are mediated by Interleukin-6 and p38 MAPK and their effects on the expression of spinal mu-opioid receptors

Activation of mitogen-activated protein kinase (MAPK) enzymes in nociceptive plasticity has been extensively studied. P38 MAPK enzyme, which can be activated by cytokines, acts as a crucial intracellular regulator of environmental changes. The aim of this study was to elucidate the cellular events during arthritis-induced hyperalgesia that are mediated by interleukin-6 and p38 MAPK, and their effects on the expression of spinal mu-opioid receptors (MORs), in different stages of arthritis in male Wistar rats. Complete Freund’s adjuvant (CFA)-induced arthritis (AA) was caused by subcutaneous injection of CFA into the rats’ hindpaw. Anti-IL-6 antibody and p38 MAPK phosphorylation inhibitor were administered during 21 days of study. Spinal MOR, p38, and phosphorylated-p38 (pp38) proteins expressions were detected by Western blotting. Daily treatment with anti-IL-6 antibody and p38 MAPK phosphorylation inhibitor, SB203580, significantly decreased paw edema in AA group. Daily anti-IL-6 and SB203580 administration caused a significant reduction in hyperalgesia in the first week of the study, but increased hyperalgesia in the next 2 weeks in experimental groups compared to the AA control group. Expression of pp38 MAPK protein significantly decreased on the 3, 7, 14, and 21 days in AA+SB203580 and AA+anti-IL6 groups compared to AA group. Additionally, daily treatment with anti-IL6 antibody and SB203580 in AA group caused significantly decrease in spinal MOR expression compared to AA control group. The results of our study can confirm that activated spinal p38 MAPK enzyme may play an important role in cellular IL-6 signaling pathways in hyperalgesia variation during different stages of AA inflammation. Also, it can be suggested that at least a part of p38 MAPK effects on hyperalgesia is mediated by spinal MOR expression variation.     

Suppression of p38 mitogen-activated protein kinase inhibits hepatitis B virus replication in human hepatoma cell: the antiviral role of nitric oxide

Summary.  The role of the p38 mitogen-activated protein kinase (MAPK) pathway in hepatitis B virus (HBV) replication was investigated in this study. After transient transfection with HBV plasmid, p38 MAPK, but not JNK or ERK1/2, was significantly phosphorylated in human hepatoma cell Huh7. Interestingly, HBV proteins and RNA synthesis were significantly inhibited by a specific inhibitor of p38 MAPK, SB203580, in a dose-dependent manner. Intracellular core-associated DNA, extracellular virion-associated DNA and covalently closed circular DNA were also significantly inhibited by SB203580. Further results showed the antiviral role of nitric oxide (NO) on the suppression of HBV replication and downregulation of p38 MAPK phosphorylation. In conclusion, these results suggested that suppression of phosphorylation of p38 MAPK by inhibitor or NO could inhibit intracellular HBV replication.     

糖基化终产物对人脐静脉内皮细胞一氧化氮合酶活性和表达的影响及二甲双胍的保护作用

目的 探讨糖基化终产物及二甲双胍对人脐静脉内皮细胞一氧化氮合酶活性和表达的影响.方法 用胶原酶法分离人脐静脉内皮细胞并加以培养.将内皮细胞与不同浓度的糖基化终产物和二甲双胍分别孵育3、6、12、24 h,CCK-8法测定人脐静脉内皮细胞增殖活性.硝酸还原酶法测定一氧化氮含量,分光光度法测定一氧化氮合酶活性,蛋白免疫印迹法检测内皮型一氧化氮合酶蛋白表达水平.结果 糖基化终产物抑制人脐静脉内皮细胞增殖,二甲双胍促进人脐静脉内皮细胞增殖.糖基化终产物抑制人脐静脉内皮细胞的一氧化氮生成和一氧化氮合酶活性(P<0.01),呈剂量、时间依赖关系.二甲双胍(与对照组相比)或与糖基化终产物共同干预(与糖基化终产物组相比)均增加人脐静脉内皮细胞一氧化氮生成和一氧化氮合酶活性(P<0.01).糖基化终产物与人脐静脉内皮细胞共同孵育24 h后,内皮型一氧化氮合酶表达水平明显下降;二甲双胍上调内皮型一氧化氮合酶的表达;与糖基化终产物组相比,糖基化终产物与二甲双胍共同干预组内皮型一氧化氮合酶表达上调(P<0.01).结论 二甲双胍能够改善糖基化终产物导致的人脐静脉内皮细胞损伤.     

p38丝裂原活化蛋白激酶对急性坏死性胰腺炎大鼠低钙血症的影响

目的 探讨p38丝裂原活化蛋白激酶(p38MAPK)信号转导通路对急性坏死性胰腺炎(ANP)大鼠低钙血症和甲状旁腺激素受体1(PTHR1)表达的影响.方法 将雄性SD大鼠72只按完全随机法分为ANP组、SB203580干预(SB)组和假手术(SO)组,每组分3、6、12 h 3个时间点,每个时间点8只.以5%牛磺脱氧胆酸钠逆行胰胆管注射建立ANP模型,SB组在造模前30 min腹腔注射p38MAPK特异抑制剂SB203580 10 mg/kg体重.观察各组血清钙浓度,蛋白质印迹法(Western blotting)分析骨组织磷酸化p38MAPK(P-p38 MAPK)和TNF-α变化,实时RT-PCR检测骨组织PTHR1 mRNA表达.结果 制模后6 h,SO组、ANP组和SB组血清钙浓度分别为(2.50±0.08)mmoL/L、(2.11±0.06)mmol/L和(2.35±0.10)mmol/L;骨组织P-p38 MAPK表达量分别为0.14±0.04、0.80±0.06和0.33±0.05;骨组织TNF-α表达量分别为0、0.91±0.04和0.44±0.03;骨组织PTHR1 mRNA表达量分别为1.00±0.12、0.23±0.04和0.44±0.06.SB组骨组织P-p38 MAPK及TNF-α表达较ANP组显著降低(P＜0.01);骨组织PTHR1 mRNA表达量及血清钙浓度较ANP组显著增加(P＜0.01).结论 p38MAPK信号转导通路可介导ANP低钙血症的发生,抑制该通路可改善ANP低钙血症.     

p38 mitogen-activated protein kinase activates eNOS in endothelial cells by an estrogen receptor alpha-dependent pathway in response to black tea polyphenols

Black tea has been shown to improve endothelial function in patients with coronary artery disease and recent data indicate the polyphenol fraction of black tea enhances endothelial nitric oxide synthase (eNOS) activity through p38 MAP kinase (p38 MAPK) activation. Because the mechanisms for this phenomenon are not yet clear, we sought to elucidate the signaling events in response to black tea polyphenols. Bovine aortic endothelial cells (BAECs) exposed to black tea polyphenols demonstrated eNOS activation that was inhibited by the estrogen receptor (ER) antagonist ICI 182,780, and siRNA-mediated silencing of ER expression. Consistent with this observation, black tea polyphenols induced time-dependent phosphorylation of ERalpha on Ser-118 that was inhibited by ICI 182,780. Phosphorylation of ERalpha on Ser-118 was due to p38 MAP kinase (p38 MAPK) as, it was inhibited by SB203580 and overexpression of dominant-negative p38alpha MAPK. Conversely, constitutively active MKK6 induced p38 MAPK activation that recapitulated the effects of polyphenols by inducing ERalpha phosphorylation and downstream activation of Akt, and eNOS. The key role of ERalpha Ser-118 phosphorylation was confirmed in eNOS-transfected COS-7 cells, as polyphenol-induced eNOS activation required cotransfection with ERalpha subject to phosphorylation at Ser-118. This residue appeared critical for functional association of ERalpha with p38 MAPK as ERalpha with Ser-118 mutated to alanine could not form a complex with p38 MAPK. These findings suggest p38 MAP kinase-mediated eNOS activation requires ERalpha and these data uncover a new mechanism of ERalpha activation that has broad implications for NO bioactivity and endothelial cell phenotype.     

p38丝裂原活化蛋白激酶抑制剂SB203580对溃疡性结肠炎肠黏膜肿瘤坏死因子α表达的影响

目的探讨溃疡性结肠炎（UC）患者肠黏膜组织中磷酸化p38丝裂原活化蛋白激酶（p38 MAPK）的表达及p38 MAPK抑制剂SB203580对活动性UC患者肠黏膜组织TNFα表达的影响。方法30例活动性UC患者被纳入本研究,以15例结肠癌患者的癌旁正常组织作为对照。免疫组化法检测UC患者肠黏膜活检组织中磷酸化p38 MAPK的表达。体外组织培养条件下观察SB203580对UC患者肠黏膜组织TNFα表达的影响,ELISA法检测培养上清液中TNFα含量。结果（1）UC患者肠黏膜磷酸化p38MAPK的表达明显高于正常肠黏膜,A值分别为549．22±32．54、143．52±11．89,阳染面积分别为[（1680．61±115．30）×10^-5、（351．68±12．73）×10^-5]μm^2,P值均〈0．01。（2）与未用SB203580处理的UC组比较,处理后UC肠黏膜组织分泌TNFα的水平明显较低,分别为（549．96±107．63、72．07±20．30）ng／L（P〈0．01）。（3）与未用SB203580处理的UC组比较,处理后UC肠黏膜组织p38 MAPK下游分子活化转录因子-2（ATF2）的活性表达明显减少,A值分别为688．32±47．37、265．82±40．25,阳染面积分别为[（2489．02±193．63）×10^-5、（1213．76±204．77）×10^-5]μm^2,P值均〈0．01,但对磷酸化p38 MAPK的表达无影响,A值分别为480．34±38．87、465．64±38．69,阳染面积分别为[（1536．68±182．16）×10^-5、（1486．26±165．49）×10^-5]μm62,P值均〉0．05。结论p38 MAPK信号传导通路在UC的发病中起着重要作用,阻断该通路可减少炎性细胞因子的释放。提示p38 MAPK信号传导通路可以为UC的治疗提供一个新的靶标,SB203580有可能成为UC治疗的新药物。