重症急性胰腺炎大鼠丝裂原活化蛋白激酶信号转导通路的动态变化

目的：阐明重症急性胰腺炎时大鼠胰腺及肺脏组织丝裂原活化蛋白激酶(MAPK)信号转导通路的变化规律。方法：以胰胆管逆行注射5％牛磺胆酸钠建立大鼠重症急性胰腺炎(SAP)模型，将SD大鼠56只随机分为对照组(即造模前)、造模后0．5、1、3、6、12和24h共7组，采用Western blot法检测胰腺及肺脏组织p38MAPK、c-Jun氨基末端激酶(JNK)活性变化。结果：对照组能检测到p38MAPK的基础活性，而检测不到JNK活性。造模后，胰腺组织的p38MAPK活性明显增高，至3h达到高峰，而肺脏组织的p38MAPK活性在6h达到高峰，两者在24h点处的p38MAPK活性仍高于基础值，而JNK的活性仅在12h点处有增高，24h点已检测不到JNK活性。结论：MAPK信号转导通路，特别是p38MAPK是重症急性胰腺炎发病过程中的重要信号转导通路。     

PPARγ激动剂对急性坏死性胰腺炎大鼠p38MAPK活化的影响

p38丝裂原活化蛋白激酶(p38MAPK)在炎症反应中通过调节炎症因子表达起重要作用[1].我们前期研究发现,过氧化酶体增殖物激活受体γ(peroxisome proliferator-activated receptorsγ,PPARγ)激动剂吡格列酮对急性坏死性胰腺炎(ANP)大鼠血清促炎细胞因子有抑制作用.本研究探讨p38MAPK在ANP发生、发展中的作用及吡格列酮对p38 MAPK的影响,进一步了解PPARγ激动剂的抗炎机制.     

磷酸化p38丝裂原活化蛋白激酶在急性肝衰竭小鼠模型及HBV相关慢加急性肝衰竭患者肝组织中的表达及意义磷酸化p38丝裂原活化蛋白激酶在急性肝衰竭小鼠模型及HBV相关慢加急性肝衰竭患者肝组织中的表达及意义

目的：研究磷酸化后的p38丝裂原活化蛋白激酶（p－p38MAPK）在氨基半乳糖（D－GalN）或脂多糖（LPS）诱导的急性肝衰竭小鼠模型以及HBV相关慢加急性肝衰竭（ACLF）患者肝脏中的表达及其意义。方法采用D－GalN／LPS诱导C57BL／6小鼠构建急性肝衰竭模型,分别在给药0、0．5、1、2、4、6、8 h设立实验组,每组4只,处死小鼠取肝组织标本进行HE染色观察肝组织结构的病理变化,分别运用蛋白免疫印迹技术半定量检测及免疫组化染色定位检测肝组织中p－p38MAPK的表达;同时对照研究p－p38MAPK在HBV－ACLF、乙型肝炎肝硬化、慢性乙型肝炎（CHB）患者肝组织中的表达情况。组间比较采用独立样本t检验。结果蛋白免疫印迹法检测p－p38MAPK在肝衰竭小鼠肝组织匀浆中的表达随时间变化持续增高,给药6 h组半定量分析表达量显著高于正常对照组,差异具有统计学意义（t＝－2.727,P＝0．034）。免疫组化染色结果显示随存活时间的延长,小鼠肝组织炎症程度逐渐加重,炎症早期主要为窦细胞表达p－p38MAPK,随着肝组织损害加重,肝细胞表达p－p38MAPK渐多,坏死肝组织附近分布大量p－p38MAPK阳性肝细胞;正常人肝组织中p－p38MAPK的表达量很低,CHB患者肝组织内可见浸润淋巴细胞及肝细胞表达p－p38MAPK,并且随病程进展呈增多趋势,与临床观察病变程度逐渐加重相一致。结论 D－GalN／LPS诱导的小鼠急性肝衰竭模型中,p－p38MAPK表达随肝组织损害加重,表明其在肝衰竭病变过程中占重要地位;在HBV－ACLF患者致病过程中,p－p38MAPK信号通路可能发挥重要作用。     

白藜芦醇通过P38 MAPK通路参与对小肠缺血再灌注继发肺损伤的保护作用

目的:探讨白藜芦醇是否通过p38丝裂原激活蛋白激酶(p38 MAPK)信号通路参与对肠缺血再灌注继发肺损伤的保护。方法:健康成年,SD大鼠,36只,随机分为正常对照组(C组,n=12)、缺血再灌注组(IR组,n=12),缺血再灌注+白藜芦醇预处理组(IRR组,n=12)。通过肠系膜动脉夹闭缺血45min后再开放再灌注4h复制大鼠小肠缺血再灌注继发肺损伤模型。计算肺湿干重比值(W/D),HE染色观察肺组织病理学变化,ELASIA法检测肺组织白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)表达,检测肺组织中磷酸化p38 MAPK(p-p38 MAPK)表达量。结果:病理切片可见IR组肺湿干比增加,组织染色可见肺泡上皮细胞肿胀,肺泡壁增宽,肺间质和肺泡腔水肿明显,肺泡内炎症细胞、红细胞和蛋白渗出明显增多。炎性因子(TNF-α,IL-6)表达增加,p38MAPK表达增加。用白藜芦醇预处理后,W/D比IR组减少,肺损伤程度较IR组减轻,p38表达较IR组减少。结论:白藜芦醇可能通过p38MAPK通路参与保护肠缺血再灌注造成的肺损伤。     

p38MAPK对大鼠肾小球系膜细胞表达COX-2的影响

目的 探讨p38丝裂原活化蛋白激酶（p38MAPK）和环氧化酶2（COX-2）的关系,从而研究p38MAPK和COX-2在糖尿病肾病（DN）中的作用机制.方法 分别以高葡萄糖、高胰岛素、过氧化氢和糖基化终产物孵育大鼠肾小球系膜细胞系HBZY-1;先以p38MAPK特异抑制剂SB203580预处理细胞系HBZY-1,再给予上述4种因素孵育细胞系HBZY-1,观察细胞系HBZY-1 p38MAPK和COX-2的表达.结果 高葡萄糖、高胰岛素、过氧化氢和糖基化终产物均可独立激活p38MAPK,使其磷酸化表达量增加,COX-2表达也明显增加;SB203580预处理后,COX-2表达被显著抑制.结论 p38MAPK调控COX-2的表达,表明p38MAPK是COX-2的上游激酶之一,p38MAPK和COX-2可能在DN的发生发展过程中起重要作用.     

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.     

p38MAPK在肝细胞癌中的研究进展

肝细胞癌(Hcc)是最常见的恶性肿瘤之一,研究表明肝细胞癌的发生与Ras.MAPK信号转导有关.p38分裂原激活蛋白激酶(p38MAPK)是丝裂原活化蛋白激酶(MAPKs)家簇中重要的一员,他参与细胞增殖、凋亡和分化,在细胞凋亡过程中起重要作用.p38MAP K与肝癌的发生发展、快速增殖、无限生长和转移密切相关,其还参与乙型肝炎病毒、丙型肝炎病毒和一些有机物致肝癌的过程:某些抗肿瘤药物通过p38MAPK发挥抗肿瘤效应.此外,p38MAPK还参与肝癌耐药形成.本文就近年来肝细胞癌在有关p38MAPK方面的研究进展作一综述.     

p38丝裂原活化蛋白激酶介导大鼠心肌缺血再灌注损伤信号传导的研究

目的:探讨p38丝裂原活化蛋白激酶(p38MAPK)在大鼠心肌缺血再灌注损伤中的作用.方法:健康成年雄性SD大鼠随机分为对照组、单纯缺血组、缺血再灌注组、抑制剂组,每组6只.抑制剂组于术前30 min腹腔注射p38MAPK抑制剂SB 203580(5 mg/kg体重).采用夹闭冠状动脉30 min后再灌注2 h的方法建立大鼠心肌缺血再灌注损伤动物模型.采用逆转录多聚合酶链反应(RT-PCR)检测p38MAPK信使核糖核酸(mRNA)表达,免疫组化法检测p-p38MAPK蛋白表达水平及心肌细胞凋亡率.结果:单纯缺血组与对照组比较,大鼠心肌组织中p-p38MAPK的蛋白含量增加,差异有统计学意义(P<0.01),p38MAPK mRNA的表达及细胞凋亡率也增加,但差异无统计学意义(P>0.05).缺血再灌注组与对照组比较,心肌组织中p38MAPK mRNA及p-p38MAPK蛋白水平和心肌细胞凋亡均显著增加,差异均有统计学意义(P<0.05～0.01).与缺血再灌注组比较,抑制剂组大鼠心肌组织p38MAPK mRNA及p-p38MAPK蛋白水平及心肌细胞凋亡均降低,(P<0.05~0.001),差异均有统计学意义.结论:p38MAPK的激活主要发生于再灌注过程;p38MAPK的活化可使缺血再灌注心肌细胞凋亡增加;抑制p38MAPK的活化可以减少缺血再灌注心肌细胞凋亡,减轻缺血再灌注所致的大鼠心肌损伤.     

p38MAPK信号转导通路与脑缺血

p38丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)是一类重要的细胞内信号转导通路,其主要作用是参与炎症调节和细胞凋亡.脑缺血时,p38 MAPK被激活,其表达水平以及上游和下游蛋白磷酸化水平均发生改变.缺血预处理可能通过p38 MAPK信号转导通路介导脑缺血后神经细胞的存亡.     

p38丝裂原活化蛋白激酶与慢性气道疾病

支气管哮喘和慢性阻塞性肺疾病是两大主要的慢性气道疾病.作为一种细胞内信号转导通路,p38丝裂原活化蛋白激酶(MAPK)介导基因表达、炎性因子产生,在炎性细胞的增殖、分化、凋亡等方面扮有关键性作用,参与慢性气道疾病的气道炎症机制.体外实验表明p38 MAPK抑制剂有抗炎作用,动物实验表明p38 MAPK抑制剂可有效抑制慢性气道疾病模型的气道炎症、气道高反应性和重塑.此外,p38 MAPK的活性异常还与激素不敏感密切相关,p38 MAPK抑制剂可提高激素的抗炎效应.     

Dynamic changes of mitogen‐activated protein kinase signal transduction in rats with severe acute pancreatitis

OBJECTIVE: To investigate the dynamic changes of mitogen‐activated protein kinase (MAPK) signal transduction in rats with severe acute pancreatitis (SAP). METHODS: The SAP model was induced by infusing the bilio‐pancreatic duct of 56 Sprague‐Dawley rats with 5% sterile sodium taurocholate solution. The rats were randomly divided into seven groups: control group, 0.5 h postoperative group, 1 h group, 3 h group, 6 h group, 12 h group and 24 h group. Western blot analysis was used to determine the activities of p38 MAPK and c‐Jun N‐terminal kinase (JNK) in the pancreas and lungs. RESULTS: In the rats of the control group, basal p38MAPK activity could be detected but not that of JNK. After SAP was induced, the p38MAPK activity in the pancreas increased markedly and peaked at 3 h, but in the lung it peaked at 6 h. The p38MAPK activity in the pancreas and lungs was significantly higher than the basal activity at the 24 h time point. The activity of JNK was only increased at the 12 h point and was not detectable at 24 h. CONCLUSION: The MAPK signal transduction pathway, in particular p38MAPK, plays an important role in the pathogenesis of SAP.     

Differential influence of p38 mitogen activated protein kinase (MAPK) inhibition on acute phase protein synthesis in human hepatoma cell lines

BACKGROUND: Inhibition of intracellular signal transduction is considered to be an interesting target for treatment in inflammation. p38 MAPK inhibitors, especially, have been developed and are now in phase II clinical trials for rheumatoid arthritis (RA). OBJECTIVE: To investigate the influence of p38 MAPK inhibition on acute phase protein (APP) production, which is dependent on both JAK/STAT and p38 MAPK pathways. METHODS: The effects of p38 MAPK inhibition on APP production and mRNA expression in four human hepatoma cell lines was investigated, after stimulation with interleukin (IL)6 and/or IL1beta or tumour necrosis factor alpha. RESULTS: Two out of four cell lines produced C reactive protein (CRP), especially after combined IL6 and IL1beta stimulation. CRP production was significantly inhibited by the p38 MAPK specific inhibitor RWJ 67657 at 1 micromol/l, which is pharmacologically relevant. Fibrinogen production was also inhibited at 1 micromol/l in all cell lines. Serum amyloid A (SAA) was produced in all four lines. In contrast with CRP, SAA production was not inhibited by RWJ 67657 at 1 micromol/l. CONCLUSION: Production and mRNA expression of CRP and fibrinogen, but not SAA production and mRNA expression, were significantly inhibited by p38 MAPK specific inhibitor in hepatoma cell lines. For p38 MAPK inhibitor treatment in RA SAA might be a better marker of disease activity than CRP and fibrinogen, because SAA is not directly affected by p38 MAPK inhibition.     

Inhibition of p38 mitogen-activated protein kinase decreases cardiomyocyte apoptosis and improves cardiac function after myocardial ischemia and reperfusion

BACKGROUND: Activation of p38 mitogen-activated protein kinase (MAPK) plays an important role in apoptotic cell death. The role of p38 MAPK in myocardial injury caused by ischemia/reperfusion, an extreme stress to the heart, is unknown. METHODS AND RESULTS: Studies were performed with isolated, Langendorff-perfused rabbit hearts. Ischemia alone caused a moderate but transient increase in p38 MAPK activity (3.5-fold increase, P<0.05 versus basal). Ischemia followed by reperfusion further activated p38 MAPK, and the maximal level of activation (6.3-fold, P<0.01) was reached 10 minutes after reperfusion. Administration of SB 203580, a p38 MAPK inhibitor, decreased myocardial apoptosis (14.7+/-3.2% versus 30.6+/-3.5% in vehicle, P<0.01) and improved postischemic cardiac function. The cardioprotective effects of SB 203580 were closely related to its inhibition of p38 MAPK. Administering SB 203580 before ischemia and during reperfusion completely inhibited p38 MAPK activation and exerted the most cardioprotective effects. In contrast, administering SB 203580 10 minutes after reperfusion (a time point when maximal MAPK activation had already been achieved) failed to convey significant cardioprotection. Moreover, inhibition of p38 MAPK attenuated myocardial necrosis after a prolonged reperfusion. CONCLUSIONS: These results demonstrate that p38 MAPK plays a pivotal role in the signal transduction pathway mediating postischemic myocardial apoptosis and that inhibiting p38 MAPK may attenuate reperfusion injury.     

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。     

p38MAPK信号转导通路与食管腺癌关系的研究进展

流行病学调查发现,亚洲人群中食管腺癌的发病率呈明显上升的趋势.大量研究证实食管腺痛的发生、发展与丝裂原活化蛋白激酶（MAPK）信号转导通路密切相关.p38MAPK信号途径是MAPK家族的重要组成部分,参与恶性肿瘤的快速增殖、迁移以及凋亡过程.本文就近年p38MAPK信号转导通路在食管腺癌中作用的研究进展作一综述.     

p38MAPK信号通路与内皮细胞激活

内皮细胞激活是内皮细胞损伤的始动因素,是引起各种不同程度的炎症反应和细胞凋亡的前提条件 ;丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK) 是哺乳动物细胞中重要的信号转导通路,其中 p38MAPK 通路在细胞应激、细胞生长、凋亡和炎症等多种生理和病理过程中起重要作用,越来越引起业界的广泛关注,本文就 p38MAPK 信号通路及其与内皮细胞激活的相关性做一综述,旨在进一步对内皮细胞损伤引发心血管疾病研究提供参考资料。     

Inhibition of p38 mitogen-activated protein kinase ameliorates cytokine up-regulated shigatoxin-1 toxicity in human brain microvascular endothelial cells

Brain injury in hemolytic-uremic syndrome (HUS) may be enhanced by inflammatory cytokine up-regulation of endothelial cell sensitivity to shigatoxin (Stx). The present study investigated whether inflammatory cytokine up-regulation of Stx toxicity could be ameliorated by inhibiting candidate signal transduction pathways. Exposure of human brain endothelial cells (HBECs) to tumor necrosis factor (TNF) greatly increased Stx-1 and Stx-2 cytotoxicity; this was reduced by inhibition of p38 mitogen-activated protein kinase (MAPK), but not c-Jun kinase. SB203580, a specific inhibitor of p38 MAPK, reduced TNF-stimulated Stx cytotoxicity in HBECs, TNF-stimulated (125)Stx-1 binding to intact HBECs, the cellular content of Gb3 (galactose alpha 1,4, galactose ss 1,4, glucose-ceramide) (the Stx receptor), and TNF-stimulated Gb3 synthase and glucosylceramide synthase activities but did not affect lactosylceramide synthase activities or mRNA content. Thus, inhibition of p38 MAPK substantially reduces inflammatory cytokine up-regulation of Stx-receptor synthesis and cell-surface expression, thereby decreasing Stx cytotoxicity. Inhibition of p38 MAPK may be of therapeutic benefit in HUS.     

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.