丝裂原活化蛋白激酶信号通路的研究进展

丝裂原活化蛋白激酶(MAPKs)是细胞内一类丝氨酸/苏氨酸蛋白激酶,参与细胞的多种生物学和生理学行为过程,包括基因的转录、细胞的分化和增殖、细胞周期调控、细胞凋亡及炎性反应等。三个主要的MAPK信号通路已知,细胞外信号调节蛋白激酶1/2(ERK1/2)信号通路、c-Jun氨基末端蛋白激酶/应激活化蛋白激酶(JNK/SAPK)信号通路和p38-MAPK信号通路。本文的重点是简要概述MAPK信号转导通路分布在某些病理或生理过程中的生物学作用特性。     

MEK/ERK通路参与支气管哮喘发病机制的研究进展

细胞外信号调节激酶(Extracellular Signal-Regulated Kinases,ERK)包括两种异构体ERK1和ERK2,二者的同源性接近90%。分裂原活化抑制剂(MEK)位于Raf-MEK-ERK通路,分为MEK1和MEK2两种,通过使Tyr和Thr两个调节位点磷酸化而激活ERK。MEK/ERK通路可以调节多种细胞功能,与多种疾病的病理过程有密切的联系。支气管哮喘反复发作,缠绵难愈,是一种以慢性气道炎症为特征的异质性疾病。MEK/ERK通路对支气管哮喘发病的多个环节起到重要的调节作用。将从MEK/ERK通路的生物学特性、MEK/ERK通路与支气管哮喘发病机制的关系两方面予以阐述。     

细胞外信号调节激酶1/2在谷氨酸引起的星形胶质细胞炎症反应中的作用

目的观察谷氨酸诱导星形胶质细胞激活炎症细胞因子表达及细胞外信号调节激酶1/2(ERK1/2)的表达情况,探讨ERK1/2在星形胶质细胞激活炎症细胞因子中的作用。方法传代体外培养的大鼠星形胶质细胞,分别用终浓度为20μmol/L和50μmol/L的谷氨酸作用30 min。应用ERK上游激酶MEK特异性阻断剂PD98059(10μmol/L)阻断ERK信号转导通路,Western blot观察阻断前后星形胶质细胞磷酸化ERK1/2、白细胞介素-1β(IL-1β)、诱导型一氧化氮合酶(iNOS)和环氧合酶-2(COX-2)蛋白表达水平的改变。结果谷氨酸使体外培养星形胶质细胞磷酸化ERK1/2蛋白表达明显增加,同时,使iNOS、COX-2I、L-1β表达明显增加;PD98059可完全阻断谷氨酸引起的ERK1/2表达增加,也可抑制谷氨酸引起的iNOS、COX-2、IL-1β蛋白表达增加。结论ERK1/2信号转导通路参与谷氨酸引起体外培养星形胶质细胞炎症反应的作用。     

人参皂苷Rg1 抑制滑膜细胞样成纤维细胞侵袭增殖及炎性因子释放的实验研究

目的：探讨人参皂苷Rg1对滑膜细胞样成纤维细胞（FLSs）增殖、侵袭和炎症因子分泌的影响,为临床治疗类风湿性关节炎（RA）提供理论及实验依据。方法：体外分离培养RA的FLSs。以肿瘤坏死因子-α (TNF-α)刺激FLSs,在上述条件中加入不同浓度Rg1 (0,0.4,4及40 mmol/L),培养24 h后,分别用实时荧光定量PCR (RT-PCR),免疫印迹实验（Western blot）和酶联免疫吸附试验（ELISA）检测白细胞介素-6 (IL-6)和白细胞介素-1β (IL-1β)的表达变化。CCK-8克隆形成以及Transwell评估细胞增殖和侵袭能力。Western-blot评估Rg1对丝裂原活化蛋白激酶/细胞外调节蛋白激酶（MAPK/ERK）通路激活的影响。结果：在基因和蛋白水平,Rg1能抑制由TNF-α诱导FLSs的IL-6和IL-1β的表达,并且限制二者的分泌;此外,Rg1能够显著抑制FLSs的侵袭与增殖;机制上,Rg1抑制了ERK的磷酸化,阻碍了MAPK/ERK通路的激活。结论：Rg1抑制FLSs中MAPK/ERK通路的激活,限制细胞的增殖和侵袭,并阻止炎性因子IL...     

长梗秦艽酮通过调节Akt和ERK1/2通路抑制人肝癌BEL-7402细胞生长

目的:研究长梗秦艽酮抑制人肝癌BEL-7402细胞生长与Akt和ERK1/2通路的关系.方法:采用MTT法观察BEL-7402细胞活性,Western blot蛋白质印记法检测Akt和ERK1/2磷酸化水平,流式细胞术分析细胞周期.结果:长梗秦艽酮能够抑制人肝癌BEL-7402细胞生长,诱导S期细胞周期阻滞,激活Akt和ERK1/2磷酸化,并凡Akt和ERK1/2抑制剂能够拮抗长梗秦艽酮对BEL-7402细胞的生长抑制和S期阻滞诱导作用.结论:长梗秦艽酮可以通过调节Akt和ERK1/2通路诱导肿瘤细胞周期阻滞,从而抑制肿瘤细胞生长.     

黄芩苷对模式识别受体TLR2/4-NOD2的作用及其成药性意义

激活模式识别受体可以引起下游信号通路启动,炎性因子表达,最终引起免疫炎性反应。无论是外源性病原微生物,还是内源性组织成分均可以配体方式不同程度上激活这种模式识别受体,引起机体免疫炎性反应。因此,抑制相关受体进而在一定程度上抑制这种免疫炎性反应,对于避免疾病过程中组织损伤具有重要的意义。黄芩苷能够特异性的抑制疾病过程中TLR2/4-NOD2的表达,抑制下游炎性因子IL-1β,IL-6和TNF-α的表达,可以减轻疾病过程中组织细胞的损伤。并且这种作用具有组织的非特异性。在成药性方面具有重要的理论和实际意义。此外,本文还从药物代谢和毒性等方面进一步探讨了其成药性。     

电针对缺血性脑卒中后神经行为学评分及ERK1/2通路影响研究

目的：观察电针曲池、足三里穴对大鼠神经行为学评分的影响及其与ERK1/2信号通路的关系.方法：采用随机数字表法,将30只大鼠分为3组,分别为假手术组、模型组、电针组,每组各10只.造模后待缺血再灌注2h后予以神经行为学评估,每天1次;造模后第1天对电针组大鼠进行电针干预,30min/次/天,疗程为3天,其余两组大鼠不作任何处理;Western Blot检测大鼠ERK1/2、p-ERK1/2表达情况并观察ERK1/2通路激活情况。结果：电针干预3天后,电针组大鼠神经行为学评分显著低于模型组（P＜0.05）,差异具有统计学意义;Western Blot示电针组大鼠p-ERK1/2蛋白水平显著高于模型组（P＜0.05）,差异具有统计学意义。结论：电针干预治疗后大鼠神经行为学明显改善,可能与激活ERK1/2信号通路有关。     

大黄素改善脂多糖引起的胰岛素抵抗机制研究

目的观察大黄素（emodin）对脂多糖（LPS）引起的炎症与胰岛素抵抗改善的机制。方法在分化成熟的C2C12骨骼肌细胞中加入脂多糖,孵育不同时间,复制体外胰岛素抵抗模型;加入不用浓度大黄素孵育,用RT-PCR方法检测细胞中炎症因子的mRNA表达情况,用免疫蛋白印记技术检测丝裂原活化蛋白激酶（MAPK）通路中细胞外信号调节激酶1/2（ERK1/2）ERK和Phos-phor-ERK的表达情况,同时检测大黄素对AMPK和ACC的影响以及对氧消耗的影响。结果①大黄素呈剂量依赖性抑制脂多糖引起的IL-6、TNF-αmRNA表达;②大黄素呈剂量依赖抑制MAPK信号通路中ERK的磷酸化激活;③大黄素能激活C2C12骨骼肌细胞中AMPK和ACC的磷酸化;④大黄素抑制分化成熟的C2C12骨骼肌细胞的氧消耗。结论大黄素可抑制LPS引起的MAPK通路中ERK的激活,进而抑制炎症因子IL-6、TNF-α的分泌;同时可抑制分化成熟的C2C12细胞的氧消耗,激活AMPK和ACC,从而促进葡萄糖转运,最终改善炎症引起的胰岛素抵抗。     

多发性硬化发病机制研究进展

多发性硬化(MS)是一类自身免疫性疾病,目前全球发病人数不断增长,病理特点主要涉及中枢神经系统炎性浸润伴随的神经胶质细胞增生,髓鞘脱失和轴突损伤等。确切的发病机制尚不十分明确,目前研究结果认为不良生活方式和人体内环境的变化会导致外周免疫细胞的激活,分泌的炎性因子浸润中枢神经系统后引发神经胶质细胞增生,继而发生髓鞘脱失和继发性轴突损伤,临床上多表现为感觉障碍、自主神经功能紊乱、共济失调等。文章对近年来报道的有关外周免疫系统、中枢神经胶质细胞、人体内环境和生活方式在MS发病机制中的作用做一概述。     

Toll样受体4信号通路在糖尿病视网膜病变中的研究进展

糖尿病视网膜病变（DR）是2型糖尿病（T2DM）患者常见的微血管并发症之一，也是导致患者失明的主要原因，但其发病机制尚未完全明确。其发生和发展可能是多种因素参与的结果，例如炎症、细胞因子、多元醇途径和氧化应激。Toll样受体4(TLR4)是经典免疫炎症反应的介导因子之一，可以通过与其配体结合，激活下游信号通路，诱导炎性因子的产生。随着人们对DR发生机制的不断探索，TLR4信号通路的激活与DR之间的迷雾渐渐被揭开。本文主要从氧化应激、炎性因子释放、血管内皮生长因子（VEGF）生成、糖基化终末产物、表观遗传学、基因多态性等方面对TLR4信号通路在DR发病机制中的研究进展进行综述。     

Amelioration of experimental autoimmune encephalomyelitis in Lewis rats treated with fucoidan

We examined whether fucoidan affected the clinical symptoms of experimental autoimmune encephalomyelitis (EAE) in rats. EAE was induced in Lewis rats that were immunized with guinea‐pig myelin basic protein (MBP) and complete Freund's adjuvant. Fucoidan (50 mg/kg, daily) was administered to rats with EAE intraperitoneally, either in the EAE induction phase from either 1 day before immunization to day 7 post‐immunization (PI), or the effector phase from day 8 to 14 PI, to test which phase of rat EAE is affected by fucoidan treatment. The onset, severity and duration of EAE paralysis in the fucoidan‐treated group in the days 8–14 PI‐treated rats, but not in days ?1–7 PI‐treated rats, were significantly delayed, suppressed and reduced, respectively, compared with the vehicle‐treated controls. Treatment with fucoidan reduced the encephalitogenic response and TNF‐α production during EAE. Moreover, the clinical amelioration coincided with decreased infiltration of inflammatory cells in the EAE‐affected spinal cord. The ameliorative effect of fucoidan on clinical paralysis in EAE‐affected rats may be mediated, in part, by the suppression of the autoreactive T cell response and inflammatory cytokine production. Copyright © 2009 John Wiley & Sons, Ltd.     

ERK1/2在黄芪多糖促进HepG2细胞凋亡中的作用

目的:阐明黄芪多糖与ERK1/2通路在HepG2细胞凋亡中的作用.方法:实验分为4组:空白对照组(control);B组,20 mg?L-1黄芪多糖3个剂量处理组(AP,20,40,80 mg?L-1黄芪多糖处理组( AP,40,80 mg?L-1),药物处理24 h后检测各指标.应用Western blot,MTT,TUNEL,线粒体膜电势检测等方法检测黄芪多糖对HepG2细胞生存凋亡及细胞中ERK1/2表达量的影响.结果:MTT与TUNEL表明黄芪多糖对HepG2细胞的凋亡具有促进作用,增加HepG2细胞的caspase-3的活性,降低(HepG2)细胞线粒体的膜电位,降低Bcl-2表达;黄芪多糖可以降低ERK1/2的表达,表明黄芪多糖的凋亡促进作用可能通过ERK1/2途径.结论:黄芪多糖可以通过抑制ERK1/2信号通路促进HepG2细胞的凋亡.     

Oligonol,a new lychee fruit‐derived low‐molecular form of polyphenol,enhances lipolysis in primary rat adipocytes through activation of the ERK1/2 pathway

The effect of Oligonol, a phenolic product from lychee fruit polyphenol (LFP) containing catechin‐type monomers and lower oligomers of proanthocyanidin, on lipolysis in primary adipocytes was investigated in order to examine the possible mechanism underlying the regulation of in vivo metabolism in fat. Oligonol significantly increased lipolysis, which was accompanied by both activation of extracellular signaling‐related kinase 1/2 (ERK1/2) and down‐regulation of perilipin protein expression, without an increase in intracellular cAMP production. The increase in lipolysis with Oligonol was prevented completely by pretreatment with either PD98059 or U0126, selective ERK1/2 inhibitors, which also prevented the reduction in the expression of perilipin protein. Tumor necrosis factor‐α also down‐regulated the expression of perilipin protein. However, there was no significant alteration in the expression of Gαi protein with Oligonol. These findings indicate that Oligonol enhances lipolysis in primary adipocytes, independent of cAMP production, but its effect is dependent on activation of the ERK1/2 pathway, leading to down‐regulation of perilipin protein expression. Copyright © 2009 John Wiley & Sons, Ltd.     

Lithocarpus polystachyus (Sweet Tea) water extract promotes human hepatocytes HL7702 proliferation through activation of HGF/AKT/ERK signaling pathway

Objective: Sweet Tea (ST), derived from the leaves of Lithocarpus polystachyus, is a Chinese folk medicine with wide pharmacological activities. However, the promotive effects of ST water extract on hepatocytes proliferation and its underlying mechanism remains still unknown. In the present study, the beneficial effects of ST water extract on human hepatocytes and its possible mechanism were investigated. Methods: MTT assay was used to detect the safety range of ST; HL7702 cells were divided into four groups: control group, ST low- (50 μg/mL), medium- (200 μg/mL) and high-concentration (800 μg/mL) groups; BrdU ELISA and EDU staining were used to observe DNA content and cell proliferation; Moreover, flow cytometry was applied to analyze the distribution of cell cycle. Furthermore, the expression of cyclin D1, CDK4, HGF/c-Met, Akt, Erk1/2 were detected by Western blot. Results: It was found that ST water extract concentration-dependent promoted human hepatocytes HL7702 cell proliferation within 72 h through accumulating the cells in S phase and G2/M phase. Furthermore, ST water extract up-regulated expression of Cyclin D1 and CDK4 proteins. Moreover, ST water extract not only increased HGF expression and phosphorylation of c-Met level, but also activated the phosphorylation levels of AKT, ERK1/2. Interestingly, both of AKT inhibitor A6730 and ERK1/2 inhibitor U0126 reversed the promotive effects of ST water extract, which further confirmed that activation of AKT and ERK1/2 were involved. Conclusion: The findings reveal that ST water extract promoted HL7702 cells proliferation through the stimulation of cell cycle mediated by activating the AKT- and ERK1/2-related pathway.     

槐定碱对大鼠学习记忆的影响及其ERK信号转导机制

目的 观察槐定碱( sophoridine,SRI)对大鼠学习记忆和海马神经元p- ERK1/2表达的影响.方法 成年SD大鼠24只随机分为生理盐水对照组、槐定碱组、PD98059+槐定碱组,腹腔注射大剂量槐定碱(47.83mg/kg)后,观察各组大鼠行为学改变,Morris水迷宫检测大鼠的学习和记忆,免疫组化测定海马组织内p- ERK1/2阳性细胞数.结果 与生理盐水对照组相比,槐定碱组大鼠逃避潜伏期明显延长,穿越平台次数明显减少(P＜0.05);海马组织内p - ERK1/2阳性细胞数明显增加(P＜0.05).经PD98059干预后,槐定碱致痫大鼠逃避潜伏期显著减小,穿越平台次数明显增多(P＜0.05);海马组织内p- ERK1/2阳性细胞数明显降低(P＜0.05).结论 槐定碱可能通过ERK信号通路损伤海马神经元,从而影响大鼠的空间学习记忆能力.     

乌萸汤含药血清对大鼠卵巢颗粒细胞ERK1／2 MAPK信号转导途径的影响

目的运用血清药理学方法观察乌萸汤含药血清对大鼠卵巢颗粒细胞（Gc）细胞外调节蛋白激酶（ERKl／2MAPK）信号转导途径的影响。方法在大鼠（GC）细胞培养体系中分别加入乌萸汤大鼠含药血清、卵泡刺激素（FsH）大鼠含药血清及正常大鼠血清,培养48h后,用蛋白质印迹法（Westernblot）测定各组大鼠Gc的ERK1／2磷酸化蛋白的相对表达量。结果各用药组GCERK1／2磷酸化蛋白相对表达量均明显升高,其中乌萸汤低剂量、中剂量血清组升高多于西药组,差异有统计学意义（P〈0．01）。结论乌萸汤含药血清能通过提高ERK1／2蛋白磷酸化水平促进Gc增殖,可以通过使用乌萸汤调控ERK1／2促进卯泡发育、成熟及排出。     

农药氰戊菊酯与雌二醇联合作用对乳腺癌MCF-7细胞的影响

目的:旨在通过乳腺癌MCF-7细胞对农药氰戊菊酯和雌二醇联合作用进行研究,评价氰戊菊酯和雌二醇联合作用的环境雌激素活性。方法:MTT法检测氰戊菊酯和雌二醇联合对MCF-7细胞生长的作用;用流式细胞仪检测氰戊菊酯和雌二醇联合对MCF-7细胞周期分布情况;采用Western Blot法测定氰戊菊酯和雌二醇联合对MCF-7细胞ERK1/2,P-ERK1/2蛋白表达的影响。结果:MTT结果显示,氰戊菊酯与雌二醇联合后能促进MCF-7细胞增殖,但增殖作用比单独应用氰戊菊酯或雌二醇效应低,两者呈拮抗作用;流式细胞仪分析氰戊菊酯和雌二醇联合作用后与空白组比较,增殖效应不明显;Western Blot结果显示,氰戊菊酯和雌二醇联合对ERK1/2蛋白无明显影响,但可以促进P-ERK1/2蛋白的表达,但与氰戊菊酯和雌二醇单独作用比较,P-ERK1/2蛋白的表达较弱。结论:氰戊菊酯与雌二醇联合作用于MCF-7细胞,增殖效应低于单独作用组,两者联用具有拮抗作用,可通过对ERK信号传导通路的影响而发挥促进细胞增殖的作用。