MAPK信号通路与上皮间质转型

丝裂原活化蛋白激酶（mitogen-activated protein kinase, MAPK）信号通路是细胞外信号刺激引起细胞核反应的共同通路,是介导上皮间质转型(epithelial-mesenchymal transition,EMT)的细胞内信号分子。许多信号分子都可以通过MAPK信号通路介导EMT的发生。进一步研究探索MAPK信号通路与EMT之间的分子机制,将有助于更好地理解EMT与疾病的发展机制,从而为疾病的治疗提供新的思路和方法。     

细胞DNA损伤应激反应中丝裂原活化蛋白激酶的信号通路

丝裂原活化蛋白激酶 (MAPKs)途径是细胞遗传毒性应激反应中主要的信号转导途径之一 ,它主要包括ERK ,JNK/SAPK ,p38等通路。各条通路都通过特异的MAPK信号级联放大反应使细胞形成应对DNA损伤的应激反应 ,从而保证细胞的正常生长和DNA复制的保真度。综述DNA损伤应激反应中的各条MAPK信号通路的激活机制     

MAPK信号通路参与调控大鼠腹腔巨噬细胞表达CRH

为了解终末巨噬细胞表达促肾上腺皮质激素释放激素(CRH)的胞内信号转导机制,明确丝裂原活化蛋白激酶(MAPK)信号通路与脂多糖(LPS)诱导的大鼠腹腔表达CRH的关系。我们利用体外培养的大鼠腹腔巨噬细胞,采用RT-PCR及ELISA方法观察MAPK信号通路中关键激酶特异性阻断剂(PD98059、SB203580、SP600125)对LPS诱导的CRH表达的影响。结果显示,LPS促进了大鼠腹腔巨噬细胞表达CRH,MAPK三条主要信号通路中关键激酶特异性阻断剂均剂量依赖性地抑制了LPS诱导的CRH表达。因此,我们认为LPS可以促进终末巨噬细胞表达CRH,而MAPK信号通路参与了该过程。     

MAPK信号通路与神经系统损伤的研究进展

丝裂酶原活化蛋白激酶(Mitogen-activated protein kinase,MAPK)是生物体内重要的信号转导通路之一,主要有ERK、p38和JNK三条途径,参与调控多种细胞应答和生理病理过程。ERK和p38在神经损伤的区域迅速激活,减少神经损伤对机体带来的影响;磷酸化JNK在神经损伤部位聚集,促进神经细胞的凋亡,加重神经损伤发生的过程。MAPK信号通路与神经系统损伤的发生、修复存在着紧密的联系     

周期性张应力诱导成纤维细胞凋亡中p38MAPK信号通路的作用

背景：当牙齿受异常咬合力时会导致牙体吸收、牙周组织的大量破坏。 目的：研究牙周膜成纤维细胞在受到周期性张应力刺激后是否发生凋亡及p38MAPK信号通路是否参与该凋亡过程。 方法：取4~7代成纤维细胞,同步化后随机分为对照组、加力组和SB203580组。加力组和SB203580组细胞加载力值为12%表面应变率,加力频率为6个循环/min,即5 s拉伸,5 s松弛。SB203580组细胞在加力前1 h加入终浓度为20 mmol/L的p38MAPK抑制剂SB203580。分别在加力6,12,24 h,取各组细胞,流式细胞仪检测细胞凋亡,RT-PCR检测细胞凋亡基因bax mRNA的表达。 结果与结论：与对照组比较,加力后成纤维细胞凋亡率及bax mRNA表达增加 (P < 0.05),且随着加力时间的延长而增强,12 h达高峰,之后逐渐下降。与加力组比较,SB203580组对应时间点细胞凋亡减少 (P < 0.05),bax mRNA表达降低。说明细胞受到力学刺激会发生凋亡,而丝裂原活化蛋白激酶p38MAPK信号通路参与了该凋亡过程。     

Toll信号通路对急性心肌梗塞患者树突状细胞功能影响

目的探讨Toll样受体(Toll-like receptor,TLR)介导丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)信号转导在体外对急性心肌梗塞(acute myocardial infarction,AMI)患者树突状细胞(dendritic cell,DC)的功能影响。方法将去年我院住院患者分3组:AMI组、稳定性心绞痛(stable pectoris,SP)组及正常对照组,各自从外周血中体外培养DC,各组DC分别应用流式细胞仪检测细胞表面TLR及CD80水平,RT-PCR检测TLR的mRNA水平,免疫印迹法检测MAPK家族中p38及JNK水平;HSP60刺激各组DC后分别应用ELISA法检测IL-6及TNF-α水平。结果 AMI组中DC表达TLR及MAPK家族水平、成熟标记物CD80水平、HSP60刺激后IL-6及TNF-α水平均明显升高(P<0.01)。结论 TLR介导MAPK信号转导参与AMI患者DC的活化过程。     

原花青素对妊娠糖尿病大鼠胰腺组织MAPK/ERK信号通路的影响

目的 探究原花青素（PAC）对妊娠糖尿病（GDM）大鼠胰腺组织丝裂原活化蛋白激酶（MAPK）/细胞外调节蛋白激酶（ERK）信号通路的影响。方法 将雌、雄性SD大鼠合笼交配（1∶2）,待成功妊娠后,随机将妊娠SD大鼠分为Ctrl组、GDM组、低、高剂量PAC组（L-PAC组、H-PAC组）、格列本脲（GLY）组,采用腹腔注射链脲佐菌素（STZ）溶液法建立GDM模型（Ctrl组除外）,检测各组糖代谢指标水平;观察各组胰腺组织病理学、胎鼠情况;检测各组胰腺组织氧化应激因子、炎性因子水平及MAPK/ERK信号通路蛋白表达情况。结果 与Ctrl组比较,GDM组空腹血糖（FBG）、空腹胰岛素（FINS）水平及胰岛素抵抗指数（HOMA-IR）、胎鼠体质量增加（P<0.05）;胰腺组织可见明显病理学改变且发生氧化应激反应及炎性反应;同时胰腺组织Raf1、MEK1/2、ERK1/2蛋白磷酸化水平增加（P<0.05）;经L-PAC、H-PAC、GLY干预后,上述情况均改善,且H-PAC、GLY改善效果更明显。结论 PAC能够改善GDM大鼠血糖水平及胰岛素抵抗,以及减轻胰腺组织氧化应激、炎症损伤...     

去泛素化酶USP14调控H_2O_2诱导的H9c2细胞氧化应激损伤

目的:观察抑制泛素特异性蛋白酶14(ubiquitin-specific protease 14,USP14)的活性对H_2O_2诱导的H9c2细胞氧化应激损伤的影响。方法:体外培养H9c2心肌细胞,用H_2O_2(25μmol/L)处理2 h,建立心肌细胞氧化应激损伤模型。将细胞分为对照(control,CON)组、模型组(H_2O_2组)、USP14抑制剂IU1处理组(IU1组)和IU1处理后建模组(IU1+H_2O_2组)。MTS法检测H9c2心肌细胞活力;流式细胞术检测细胞内活性氧簇(ROS)的产生和细胞存活率;Western blot法检测丝裂原活化蛋白激酶家族相关蛋白的表达变化。结果:与CON组相比,H_2O_2组细胞活力、细胞存活率显著降低,细胞内ROS含量、Bax/Bcl-2、P53、p-ERK1/2、p-JNK和p-P38的蛋白水平显著增加(P0.05);与H_2O_2组比较,IU1+H_2O_2组细胞活力、细胞存活率显著增加,细胞内ROS含量、Bax/Bcl-2、P53、p-ERK1/2、p-JNK和p-P38蛋白水平显著降低(P0.05)。结论:抑制USP14活性可以减轻氧化应激条件下H9c2心肌细胞的损伤,其机制可能与抑制丝裂原活化蛋白激酶信号活化和下调凋亡相关蛋白有关。     

p38MAPK通路参与炎性痛及电针干预的可能性

丝裂原活化蛋白激酶(mitogen-activated protein kinases,MAPKs)是细胞内重要的信号传导系统之一.p38MAPK是丝裂原活化蛋白激酶的重要组成部分之一,在炎症性疼痛的发生发展过程中发挥着重要作用,已有大量资料表明电针具有较好的抗炎镇痛作用,同时有研究发现电针具有调节p38MAPK活化的作用,所以电针在炎性痛疾病中对p38MAPK通路干预存在可能性.     

p38丝裂原活化蛋白激酶通路在非对称性二甲基精氨酸诱导内皮细胞通透性增高中的作用

目的探讨非对称性二甲基精氨酸(ADMA)对单层内皮细胞通透性的影响,以及氧化应激、p38丝裂原活化蛋白激酶(MAPK)通路在此过程中的作用。方法利用Transwell小室建立单层内皮细胞屏障结构,设立实验组和对照组,实验组经浓度25、50、100、200μmol/L ADMA作用24 h和100μmol/L ADMA分别刺激细胞4、8、16、24 h,或分别经烟酰胺腺嘌呤二核苷酸磷酸(NADPH)氧化酶抑制剂、p38 MAPK抑制剂预处理细胞后再加入ADMA刺激。随后用异硫氰酸荧光素(FITC)标记的右旋糖酐漏出法测定单层内皮细胞的通透系数Pa值,并用免疫荧光染色显示细胞骨架及细胞间连接的形态学改变。结果 ADMA呈剂量及时间依赖性的增加单层内皮细胞的通透性,同时促进内皮细胞中应力纤维的形成并破坏细胞间连接。NADPH氧化酶抑制剂和p38 MAPK抑制剂均可对抗ADMA的上述作用。结论 ADMA通过引起氧化应激,激活p38 MAPK通路,改变细胞骨架及细胞间连接的结构,使单层内皮细胞通透性增高。     

p38 MAPK signaling mediates retinoic acid-induced CD103 expression in human dendritic cells

Retinoic acid (RA) is an active derivative of vitamin A and a key regulator of immune cell function. In dendritic cells (DCs), RA drives the expression of CD103 (integrin α_E), a functionally relevant DC subset marker. In this study, we analyzed the cell type specificity and the molecular mechanisms involved in RA-induced CD103 expression. We show that RA treatment caused a significant up-regulation of CD103 in differentiated monocyte-derived DCs and blood DCs, but not in differentiated monocyte-derived macrophages or T cells. DC treatment with an RA receptor α (RARα) agonist led to an increase in CD103 expression similar to that in RA treatment, whereas RARA gene silencing with small interfering RNA blocked RA-induced up-regulation of CD103, pointing to a major role of RARα in the regulation of CD103 expression. To elucidate RA-induced signaling downstream of RARα, we used Western blot analysis of RA-treated DCs and showed a significant increase of p38 mitogen-activated protein kinase (MAPK) phosphorylation. In addition, DCs cultured with RA and a p38 MAPK inhibitor had a significantly reduced expression of CD103 compared with DCs cultured with RA only, indicating that p38 MAPK is involved in CD103 regulation. In summary, these findings suggest that the RA-induced expression of CD103 is specific to DCs, is mediated primarily through RARα and involves p38 MAPK signaling.     

白细胞介素1β通过p38信号通路上调系膜细胞表达白细胞介素6

目的：探讨p38信号通路(p38MAPK)在白细胞介素1(IL-1)β上调肾小球系膜细胞表达白细胞介素6(IL-6)中的作用。方法：应用Western Blotting检测p38MAPK在IL-1β诱导的肾小球系膜细胞炎症反应中的活化程度，应用逆转录-聚合酶链反应(RT-PCR)和ELJSA法检测IL-1β诱导的系膜细胞促炎症介质IL-6的表达水平并观察p38MAPK特异性抑制剂SB203580对其mRNA的转录和蛋白质生成的影响。结果：IL-1β以时间和剂量依赖方式刺激系膜细胞引起p38MAPK的活化，并明显上调系膜细胞IL-6表达。SB203580以剂量依赖方式从基因转录和翻译水平显著抑制IL-1β诱导的IL-6表达。结论：p38MAPK在IL-1β诱导的肾小球系膜细胞炎症反应产生炎症介质IL-6中起重要作用。     

SASH1通过MAP2K2和MAP4K4与ERK信号通路交互作用

目的 探讨新候选抑癌基因SASH1与细胞外调节蛋白激酶(ERK)信号通路的两个关键分子MAP2K2和MAP4K4的蛋白-蛋白相互作用关系.方法 用Xho Ⅰ和HpaⅠ构建SBP-Flag-SASH1-pBABE-puro反转录病毒载体,转染HEK-293T细胞,通过嘌呤霉素筛选出稳定表达外源性SASH1基因的细胞系.Western blot检测外源性Flag-SASH1蛋白表达,利用pull-down实验、质谱技术、免疫沉淀鉴定和分析与SASH1结合的并可能调节细胞增殖、转移和凋亡等的关键蛋白.用SASH1-siRNA1和SASH1-siRNA2分别转染MDA-MB-231细胞系,以空白组和Negative-siRNA组为对照.72 h后Western blot检测SASH1的干扰效果和P-ERK1/2水平.结果 成功构建稳定表达SBP-Flag-SASH1-pBABE-puro重组质粒的HEK-293T细胞系,SASH1与MAP2K2和MAP4K4结合并发生相互作用.SASH1-siRNA有效抑制MDA-MB-231细胞SASH1蛋白表达(P＜0.05),且P-ERK1/2在SASH1抑制组表达增加.结论 MAP2K2和MAP4K4是SASH1的重要的候选结合蛋白,SASH1可能通过与其直接或间接结合串话ERK信号传导通路,进而调节细胞增殖和迁移等细胞生物学功能.     

拉曼光谱技术检测川芎嗪对视网膜色素上皮细胞氧化应激损伤的保护作用

目的:年龄相关性黄斑变性（AMD）是致盲的主要原因之一。氧化应激所引起的视网膜色素上皮（RPE）细胞变性在AMD的发病机制中发挥了关键作用。本文利用无创、无需标签、高灵敏度的拉曼光谱探究川芎嗪对氧化损伤的人RPE细胞的保护机制。方法:进行拉曼光谱采集之前,将除对照组外的其余两组RPE细胞（ARPE-19）用200 μmol/mL H2O2预孵育,24 h后在保护组细胞中加入200 μmol/mL川芎嗪。所有干预结束后,用MultiskanGO （Thermo, USA）微板法测定细胞内活性氧自由基的含量,用InVia微拉曼系统对3组细胞进行拉曼光谱分析。结果:活性氧检测显示川芎嗪对H2O2诱导的RPE细胞氧化应激损伤有较好的抑制作用。拉曼光谱结果显示细胞氧化应激损伤主要体现在氨基酸类分子上,而川芎嗪的加入不仅逆转了归属于脂质的谱带810 cm-1和840 cm-1峰强度比值的变化趋势,还使H2O2干预后显著提高的归属于各氨基酸谱带的峰强度值有所下降。与之前激光光镊拉曼光谱结果不同,活性氧自由基没有触发酰胺的脱酰胺反应,反而是川芎嗪的干预使得归属于酰胺的拉曼光谱强度发生改变。结论:通过对人RPE细胞拉曼光谱变化的分析,揭示过氧化氢和抗氧化剂川芎嗪潜在的作用靶点,为更好地探究RPE细胞氧化应激的损伤机制奠定了基础。     

Ethanol-induced oxidative stress is mediated by p38 MAPK pathway in mouse hippocampal cells

It has been known that ethanol causes neuronal cell death through oxidative stress. Ethanol itself and reactive oxygen species (ROS) produced by ethanol modulate intracellular signaling pathways including mitogen-activated protein kinase (MAPK) cascades. This study was conducted to examine the impact of ethanol on MAPK signaling in HT22 cells. Ethanol (100 and 400 mM) caused activation of ERK, p38 MAPK, and JNK. ERK activation occurred in early time and p38 MAPK activation was evident when ERK activation was diminished. Specific inhibitor of p38 MAPK (SB203580) protected HT22 cells against ethanol, which was accompanied by an inhibition of ROS accumulation. However, inhibitors of ERK (U0126) and JNK (SP600125) had no effects on ethanol-induced neuronal cell death when they are treated with ethanol for 24 h. These results suggest that p38 MAPK may have important roles in ROS accumulation during ethanol-induced oxidative stress in HT22 cells.     

The response of intestinal stem cells and epithelium after alemtuzumab administration

Intestinal stem cells may have important roles in the maintenance of epithelial integrity during tissue repair. Alemtuzumab is a humanized anti-CD52 lymphocytic antibody that is increasingly being used to induce immunosuppression; intestinal barrier function is impaired during treatment with alemtuzumab. We investigated the response of intestinal stem cells to epithelial damage resulting from alemtuzumab treatment. Intestinal epithelial cell loss and abnormal Paneth cell morphology were found following a single dose of alemtuzumab. The animals receiving alemtuzumab exhibited increased apoptosis in the villi 3 days after alemtuzumab treatment and in the crypt on day 9, but apoptosis was scarce on day 35. We assessed expression of Musashi-1- and Lgr5-positive stem cells following alemtuzumab treatment. Increased numbers of cells staining positive for both Musashi-1 and Lgr5 were found in the stem cell zone after alemtuzumab treatment for 3 and 9 days. These data indicated that the epithelial cells were injured following alemtuzumab treatment, with the associated expansion of intestinal stem cells. After alemtuzumab treatment for 35 days, the numbers of intestinal epithelial cells and intestinal stem cells returned to normal. This study suggests that alemtuzumab treatment induced the increase in stem cells, resulting in the availability of more enterocytes for repair.     

The triggering of apoptosis in macrophages by pristine graphene through the MAPK and TGF-beta signaling pathways

With the development of nanotechnology and the wide use of graphene, it has become necessary to assess the potential biological adverse effects of graphene. However, most of the recent publications are focused on various modified graphenes. We demonstrated biological effects of commercial pristine graphene in murine RAW 264.7 macrophages, which is an important effector cells of the innate immune system. We found that the pristine graphene can induce cytotoxicity through the depletion of the mitochondrial membrane potential (MMP) and the increase of intracellular reactive oxygen species (ROS), then trigger apoptosis by activation of the mitochondrial pathway. The MAPKs (JNK, ERK and p38) as well as the TGF-beta-related signaling pathways were found to be activated in the pristine grapheme-treated cells, which activated Bim and Bax, two pro-apoptotic member of Bcl-2 protein family. Consequently, the caspase 3 and its downstream effector proteins such as PARP were activated and the execution of apoptosis was initiated. This study provides an insight for the suppression of the apoptosis induced by the graphene through the mitochondrial pathways, the MAPKs- and TGF-beta-related signaling pathways.     

Clothianidin induces DNA damage and oxidative stress in bronchial epithelial cells

Clothianidin (CHN) is a member of the neonicotinoid group of insecticides. Its oxidative and DNA damage potential for human lung cells are not known. Therefore, the present study was designed to examine the effects of CHN on DNA damage and oxidative stress in human bronchial epithelial cells (BEAS-2B) treated with CHN for 24, 72, and 120 hr. Our results indicate that CHN decreased cell viability in a concentration-dependent manner. CHN induced DNA single-strand breaks because alkaline comet parameters such as tail intensity, DNA in the tail, tail moment, and tail length increased. All CHN concentrations also significantly induced the formation of DNA double-strand breaks (DSBs) because it increased phosphorylated H2AX protein foci for all treatment times and p53-binding protein 1 foci for all treatments except for the lowest concentration (0.15 mM) of 120-hr treatment. DNA damage caused by DNA DSBs was not repaired in a 24-hr recovery period. CHN also induced oxidative stress by decreasing reduced glutathione and increasing lipid peroxidation. These results make it necessary to conduct studies about the detailed carcinogenic potential of CHN in humans because it can induce both oxidative and DNA damage.     

Effect of syngeneic thymocytes on proliferation of the small intestinal epithelium in mice

Bulletin of Experimental Biology and Medicine -