ERK1/2信号通路介导同型半胱氨酸对PC12细胞的损伤作用

目的观察同型半胱氨酸(Homocysteine,Hcy)对PC12细胞的损伤作用,探讨胞外信号调节蛋白激酶1/2(extracellular signal-regulated protein kinases1and2,ERK1/2)通路在其中的作用。方法台盼蓝拒染法和MTT比色法检测细胞存活率,相差倒置显微镜观察细胞形态,Hoechst33258染色荧光照相术检测细胞凋亡,罗丹明123染色荧光照相术和流式细胞术检测细胞线粒体膜电位(mitochondrial membrane potential,MMP),Western blot检测ERK1/2磷酸化的水平。结果Hcy(2.5～20mmol/L)作用24h后,可浓度依赖性地抑制PC12细胞的存活率;10mmol/L Hcy处理24h后,PC12细胞出现核固缩等典型的凋亡特征;Hcy能明显地降低PC12细胞的MMP;Hcy能诱导ERK1/2磷酸化,特异性的ERK1/2阻断剂U0126可显著抑制Hcy对PC12细胞的损伤作用。结论Hcy可引起PC12细胞损伤,此作用与其抑制MMP及诱导ERK1/2磷酸化有关。     

LncRNA CCAT1通过MAPK/ERK通路影响子宫内膜癌细胞的侵袭转移

目的:探讨长链非编码RNA(LncRNA)CCAT1对子宫内膜癌细胞侵袭迁移和丝裂原活化激酶/胞外信号调节激酶(MAPK/ERK)信号通路影响,阐明CCAT1在子宫内膜癌侵袭迁移中的作用及可能机制.方法:将KLE细胞分为空白对照组(BC组)、阴性对照组(NC组)、CCAT1-siRNA组和CCAT1-siRNA+EGF...     

let-7a通过抑制MAP4K3/MKK4/JNK信号通路减少脑出血大鼠神经元调亡

目的:研究微小RNA let-7a对脑出血(ICH)大鼠神经元凋亡的影响及其分子机制。方法:从48只健康SD大鼠中随机选取8只作为假手术组,将2μLⅦ型胶原酶注入其余大鼠苍白球以构建ICH模型。将造模后的大鼠随机分为模型(2μL生理盐水)组、let-7a激动剂(agomir)组、阴性对照(NC)agomir组、let-7a拮抗剂(antagomir)组和NC antagomir组,每组8只,在侧脑室注射相应药物。7 d后进行神经功能评分;HE染色观察病理损伤;RT-qPCR和Western blot检测相关蛋白表达水平;TUNEL染色检测神经元凋亡情况;利用生物信息学软件预测let-7a与丝裂原活化的蛋白激酶激酶激酶激酶3(MAP4K3)的靶向关系,并在HEK293T细胞中用双萤光素酶报告基因实验进一步验证。结果:动物实验中,let-7a过表达时,神经功能评分降低,病理损伤减轻,胶质细胞原纤维酸性蛋白(GFAP)低表达,神经元凋亡减少,cleaved caspase-3和cleaved PARP低表达(P<0. 05)。细胞实验中,MAP4K3是let-7a的靶基因之一,且两者为...     

PP60C-SRC/ERK1/2信号通路调节大鼠精原干细胞活性

目的 研究PP60C-SRC通过磷酸化的细胞外调节激酶1/2 (p-ERK1/2)调节体外培养的9日龄大鼠精原干细胞的活性。方法 用MTT观察反义C-SRC脱氧寡核苷酸(ODNs)及PD98059对精原干细胞活性的影响;用Western blot检测PP60C-SRC和p-ERK1/2的表达。结果 与空白对照组相比,10 ?mol/L反义C-SRC ODNs作用12 h后精原干细胞活性下降了8.1 % (P＜0.05),10 ?mol/L PD98059作用24 h后精原干细胞活性下降了9.4 %(P＜0.01)。反义C-SRC ODNs组PP60C-SRC、p-ERK1/2蛋白表达与空白对照组相比分别下降了33.8 %和45.3 % (均P<0.01);10 ?mol/L PD98059作用精原干细胞24 h后,p-ERK1/2蛋白表达下降了34.5 %。结论 PP60C-SRC可能通过p-ERK1/2蛋白而调节精原干细胞的活性。     

心-面-皮肤综合征MAP2K1基因新发变异一例

目的探讨MAP2K1基因变异所致的心-面-皮肤综合征(cardio-facio-cutaneous syndrome,CFCS)基因型与表型的对应关系。方法收集先证者及其父母的外周血样,提取DNA,采用全外显子组测序对先证者进行检测,用Sanger测序对先证者及父母进行验证。结果先证者为1岁8个月的男性,临床表现为身材矮小、精神运动发育迟缓、大头畸形、特殊面容、先天性心脏病等多发异常。全外显子组测序发现其携带MAP2K1基因c.389A>G(p.Tyr130Cys)杂合错义变异,Sanger测序证实其为新发变异。根据ACMG/AMP指南,判定为致病性变异。结论本例患儿存在明显的行为异常、食欲佳、三尖瓣返流,有别于既往报道的病例,因此丰富了MAP2K1基因变异所导致的CFCS的临床表型谱。     

睾酮诱导大鼠心肌细胞肥大反应并上调ERK1/2蛋白表达

目的探讨细胞外信号调节激酶(ERK1/2蛋白)在睾酮对大鼠心肌肥大中的作用。方法用差速贴壁法分离及纯化培养新生SD大鼠心肌细胞,以Bradford法测定心肌细胞蛋白质含量,同位素法分析3H-亮氨酸(3H-Leu)掺入,IBAS图像分析心肌细胞表面积,以免疫印迹法检测心肌细胞ERK1/2蛋白表达水平。结果生理浓度的T作用于大鼠心肌细胞24 h后,细胞蛋白质含量3、H-Leu掺入和细胞表面积均增加,其中以10-8mol/L作用最强。雄激素受体拮抗剂氟他胺(Flu)10-5mol/L预处理2 h可抑制T诱导的心肌细胞蛋白质含量的增加,而Flu单独作用对心肌细胞蛋白质含量无影响。ERK1/2信号通路的特异性抑制剂PD98059 50μmol/L预处理2 h,可抑制T诱导的心肌细胞3H-Leu掺入的增加;10-8mol/L T作用24 h使心肌细胞的ERK1/2的蛋白表达显著增加;10-5mol/L Flu预处理2 h可逆转T诱导的心肌细胞ERK1/2蛋白表达的增加。结论生理浓度的T可以诱导心肌细胞肥大反应,该作用可能由ERK1/2信号通路介导。T通过雄激素受体(AR)上调ERK1/2蛋白表达。     

ERK1/2和TGF-β1在自发性高血压大鼠心脏中的表达上调

目的 探讨自发性高血压大鼠(SHR)心脏细胞外信号调节激酶1/2(ERK1/2)和转化生长因子β1(TGF-β1)表达的意义.方法 采用免疫组化和Western blot方法检测心脏ERK1/2和TGF-β1的表达.结果 在SHR8、SHR16、SHR20三个周龄组中,心肌间小动脉内皮细胞中的ERK1/2阳性率分别为15.38%、76.97%和72.72%,SHR16和SHR20组心肌间血管平滑肌细胞(VSMC)ERK1/2染色阳性率为5.49%和6.83%,均显著高于对照组(P＜0.05).在SHR16和SHR20组中ERK1/2蛋白含量明显高于对照组(P＜0.05);心脏中TGF-β1含量明显高于同周龄的SD大鼠(P＜0.05).心脏中ERK1/2和TGF-β1表达量与平均动脉血压正相关(P＜0.05).结论 在SHR心脏组织中TGF-β1表达增加并与ERK1/2相互作用,可能参与了心脏病变的形成.     

不同标本制备法对小鼠小肠组织中ERK1/2和pERK1/2免疫组织化学定位的影响

目的:本研究针对丝裂原活化蛋白激酶(MAPK)家族成员细胞外信号调节激酶(ERK1/2),以及磷酸化的ERK1/2(pERK1/2),探讨不给任何刺激时,用不同标本制备法检测ERK1/2在小鼠小肠组织中的免疫组织化学定位。方法:分别应用灌流固定脱水法(PF-DH),浸泡固定脱水法(IM-DH),快速冻结-冻结置换法(QF-FS)制备的标本,通过免疫组织化学显色检测ERK1/2和pERK1/2在肠上皮中的定位。结果:应用PF-DH法,ERK1/2位于几乎所有上皮细胞的核中,而pERK1/2在上皮细胞中很难检测到。应用IM-DH法,ERK1/2位于所有上皮细胞的胞质和核内,pERK1/2仅位于小肠绒毛顶部的上皮细胞内,而不存在于肠隐窝区域的上皮细胞中。应用QF-FS法制备的标本中,ERK1/2定位于所有上皮细胞的胞质中,而pERK1/2主要存在于肠隐窝部位和肠绒毛顶部的上皮细胞中。结论:本研究结果提示,用不同的标本制备方法会影响ERK1/2的免疫组织化学定位。通过比较不同标本制备方法取材的小鼠小肠组织中的ERK1/2和pERK1/2的免疫组织化学定位,得出QF-FS法可能为最接近活体状态的小鼠小肠组织中的ERK1/2和pERK1/2定位的方法。     

ERK信号通路在神经细胞命运中的双重角色

细胞外信号调节激酶（ERK）,涉及细胞存活,增殖,转化,抑制凋亡的效应已经被广泛描述。近年来,一些研究发现并鉴定了ERK的一些新的、预料之外的作用,它能够直接参与细胞死亡信号,尤其是持续的ERK激活导致细胞的死亡。ERK信号通路也是神经系统中重要转导通路,它的激活导致了神经细胞的存活与死亡的双重作用。本文将对ERK通路在神经细胞命运中的双重角色的研究进展,做一综述。     

葛根素通过ERK1/2信号通路促进内皮细胞增殖

目的:体外观察葛根素对人脐静脉内皮细胞(HUVEC)的促增殖作用,并对其机制进行初步探讨。方法:采用四甲基偶氮唑蓝(MTT)法检测不同浓度葛根素对HUVEC细胞增殖的影响;流式细胞术检测细胞凋亡;Western blot检测p-ERK1/2蛋白表达水平。结果:葛根素能剂量依赖性促进HUVEC增殖,在80μM效果最明显,且作用36h时,能显著减少早期凋亡,激活ERK1/2磷酸化。结论:葛根素素对人脐静脉内皮细胞有明显的促进增殖作用,其作用可能与ERK1/2的活化有关。     

SASH1 inhibits proliferation and invasion of thyroid cancer cells through PI3K/Akt signaling pathway

The SASH1 (SAM- and SH3-domain containing 1) gene, a member of the SLY-family of signal adapter proteins, has an important regulatory role in tumorigenesis, but its implication in thyroid carcinoma has not been yet investigated. In this study, we investigated the role of SASH1 in proliferation and invasion of thyroid cancer cells and the underlying mechanism. Our results demonstrated that SASH1 is down-regulated in thyroid cancer cells. Overexpression of SASH1 inhibits thyroid cancer cell proliferation, migration and invasion with decreased epithelial-mesenchymal transition (EMT). Mechanistically, overexpression of SASH1 inhibits thyroid cancer cell proliferation and invasion through down-regulation of PI3K and Akt phosphorylation. Taken together, the present study showed that the loss or inhibition of SASH1 expression may play an important role in thyroid cancer development, invasion, and metastasis and that SASH1 may be a potential therapeutic target for the treatment of thyroid cancer.     

Mutation rate of MAP2K4/MKK4 in breast carcinoma

The stress‐activated protein kinase (SAPK) pathways represent phosphorylation cascades that convey pro‐apoptotic signals. The relevant inputs include Ras proteins as well as exposure of cells to ultraviolet light, tumor‐necrosis factor, and other stress‐related inputs. The mitogen‐activated protein kinase kinase (MAPKK) homolog MAP2K4 (MKK4, SEK, JNKK1) is a centrally‐placed mediator of the SAPK pathways. MAP2K4 mutations or homozygous deletions are reported in about 5% of a wide variety of tumor types. The exception is breast cancer, where genetic inactivation in 3 of 22 (15%) cell lines had suggested that the mutational involvement of MAP2K4 might be accentuated in this tumor type. This finding might have represented an important difference, or solely a chance numerical variation. To address this question, we studied an independent panel of 20 breast cancer cell lines and xenografts for MAP2K4 alterations. We found a splice acceptor mutation accompanied by loss of the other allele in the cell line MPE600. This was the sole alteration in this panel (5% of tumors). These data seem to re‐establish a rather consistent rate of genetic inactivation of MAP2K4 among most tumor types, including breast cancer. The genetic evaluation of other mediators of the SAPK pathways might offer insight into a promising, but as yet poorly defined, tumor‐suppressive system. © 2001 Wiley‐Liss, Inc.     

IL-15通过ERK1/2信号途径对NK细胞活性的调节

目的 阐明IL-15在NK细胞功能调节中的作用及信号转导途径的活化。方法 直接免疫荧光证实NK-92细胞膜表达表达IL-15Rα链，制备NK-92细胞的全细胞提取物进行Western blot检测IL-15诱导的信号转导途径，MTT方法评价IL-15对NK细胞增殖和细胞毒能力的调节作用。结果 NK-92细胞表面存在IL-15Rα链的表达，构成IL-15与NK相互作用的分子基础。在IL-2依赖性NK细胞系NK-92中，较低剂量的IL-15（25-100U/ml)可以完全替代IL-2以维持NK细胞的杀伤活性并对NK细胞的生长起促进作用。免疫印迹显示IL-15迅速活化ERK1/2（extracellular regulated kinase 1and2)信号途径，而其它信号分子（STAT1，STAT3，STAT6，P38MAPK，PI-3K，NF-кB)并不被IL-15活化，提示ERK1/2是IL-15调节NK细胞功能中重要的信号分子。结论 IL-15对NK细胞具有强大的调节作用。IL-15通过ERK1/2信号途径完成对NK细胞活性的调节。     

葡萄籽原花青素对放射性脑损伤大鼠海马区细胞外信号调节激酶1/2活性的影响

目的:观察葡萄籽原花青素(GSPE)对放射性脑损伤大鼠海马区细胞外信号调节激酶1/2(ERK1/2)活性的影响。方法:雄性SD大鼠随机分为对照组,模型组,低、高剂量GSPE组。用直线加速器进行脑部照射22 Gy制作放射性脑损伤模型。干湿重法观察脑组织含水量;H-E染色观察海马区神经细胞形态变化;免疫组织化学及免疫印迹检测磷酸化ERK1/2表达;穿梭箱评测大鼠学习能力。结果:与模型组比较,GSPE组脑组织含水量降低,海马区神经细胞结构损伤减轻、磷酸化ERK1/2表达水平增高,动物主动回避反应率升高、被动回避潜伏期缩短;上述变化在高剂量GSPE组最为显著。结论:GSPE对放射性脑损伤大鼠有较好的防治作用,与增强海马区ERK1/2活性有关。     

Cardioprotection induced by hydrogen sulfide preconditioning involves activation of ERK and PI3K/Akt pathways

We previously reported that hydrogen sulfide (H₂S) preconditioning (SP) produces cardioprotective effects against ischemia in rat cardiac myocytes. The present study aims to elucidate the signaling mechanisms involved in SP-induced cardioprotection by investigating the role of extracellular signal regulated kinase (ERK1/2) and phosphatidylinositol 3-kinase (PI3K)/Akt. We found that preconditioning with NaHS (a H₂S donor) for three cycles significantly decreased myocardial infarct size and improved heart contractile function in the isolated rat hearts. NaHS (1–100 μM) concentration-dependently increased cell viability and percentage of rod-shaped cardiac myocytes. Blockade of ERK1/2 with PD 98059 or PI3K/Akt with LY-294002 or Akt inhibitor III during either preconditioning or ischemia periods significantly attenuated the cardioprotection of SP, suggesting that both ERK1/2 and PI3K/Akt triggered and mediated the cardioprotection of SP. Moreover, SP induced ERK1/2 and Akt phosphorylation in isolated hearts. The phosphorylation of ERK1/2 induced by SP was attenuated by either glibenclamide, an ATP-sensitive K⁺ channel (K_ATP) blocker, or chelerythrine, a specific protein kinase C (PKC) blocker. In addition, ischemic-preconditioning-induced ERK1/2 activation was reversed by inhibiting endogenous H₂S production, suggesting that ERK1/2 activation induced by ischemic preconditioning was, at least partly, mediated by endogenous H₂S. In conclusion, K_ATP/PKC/ERK1/2 and PI3K/Akt pathways contributed to SP-induced cardioprotection.     

Adipophilin通过ERK1/2-AP-1途径诱导炎症因子的表达

目的:观察巨噬细胞中脂肪分化相关蛋白(adipophilin)对炎症因子表达的影响,阐明adipophilin促进巨噬细胞炎症因子表达的机制。方法:将已构建成功的adipophilin稳定高、低表达逆转录病毒载体转染入PA317包装细胞,制备adipophilin高和低表达的RAW264.7细胞;收集已转染成功的各组细胞上清液,用ELISA方法检测IL-6、TNF-α、MCP-1等炎症因子在细胞培养液中的浓度。Western blot检测各组细胞AP-1、p-AP-1、ERK1/2及p-ERK1/2的蛋白水平;用ERK1/2抑制剂PD98059或AP-1抑制剂curcumin孵育细胞,检测各组细胞中以上指标的变化情况。结果:高表达adipophilin的细胞上清液中炎症因子IL-6、MCP-1和TNF-α浓度明显增高,adipophilin siRNA组细胞中的炎症因子降低;高表达adipophilin的细胞中p-ERK1/2和p-AP-1的蛋白水平增高,adipophilin siRNA组则减少;ERK1/2抑制剂PD98059使AP-1蛋白活性明显下调;给予AP-1抑制剂curcumin后,细胞培养液中的IL-6、MCP-1和TNF-α浓度明显下降。结论:Adipophilin在RAW264.7巨噬细胞中能够促进炎症因子的表达。     

Dichotomous role of the serine/threonine kinase MAP4K4 in pancreatic ductal adenocarcinoma onset and metastasis through control of AKT and ERK pathways

MAP4K4 is a serine/threonine kinase of the STE20 family involved in the regulation of actin cytoskeleton dynamics and cell motility. It has been proposed as a target of angiogenesis and inhibitors show potential in cardioprotection. MAP4K4 also mediates cell invasion in vitro, is overexpressed in various types of cancer, and is associated with poor patient prognosis. Recently, MAP4K4 has been shown to be overexpressed in pancreatic cancer, but its role in tumour initiation, progression, and metastasis is unknown. Here, using the Kras^G12D Trp53^R172H Pdx1-Cre (KPC) mouse model of pancreatic ductal adenocarcinoma (PDAC), we show that deletion of Map4k4 drives tumour initiation and progression. Moreover, we report that the acceleration of tumour onset is also associated with an overactivation of ERK and AKT, two major downstream effectors of KRAS, in vitro and in vivo. In contrast to the accelerated tumour onset caused by loss of MAP4K4, we observed a reduction in metastatic burden with both the KPC model and in an intraperitoneal transplant assay indicating a major role of MAP4K4 in metastatic seeding. In summary, our study sheds light on the dichotomous role of MAP4K4 in the initiation of PDAC onset, progression, and metastatic dissemination. It also identifies MAP4K4 as a possible druggable target against pancreatic cancer spread, but with the caveat that targeting MAP4K4 might accelerate early tumorigenesis. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.     

Metabotropic glutamate receptor 1 promotes cementoblast proliferation via MAP kinase signaling pathways

Purpose/aim: Glutamate is one of the signaling molecules responsible for transmission in the central nervous system. Periodontal ligament (PDL) cells were recently reported to express metabotropic glutamate receptors (mGluRs). However, the functions of mGluR signaling in PDL cells or PDL-related cells remain largely unknown. The aim of this study was to investigate the expression and function of mGluRs in PDL-related cells. Materials and methods: OCCM-30 cells, immortalized murine cementoblasts, were stimulated with l-glutamate or mGluRs antagonists. The cells’ proliferative response was evaluated using a colorimetric assay and gene expression was assessed using real-time polymerase chain reaction. The nuclear translocation of cyclin D1 was evaluated by immunohistochemistry. Results: l-Glutamate promoted the proliferation of OCCM-30 cells, which expressed mGluR1, but not mGluR5. Dihydroxyphenylglycine (DHPG), an agonist of group I mGluRs (mGluR1 and mGluR5), also promoted cell proliferation, and this was inhibited by LY456236, an mGluR1 antagonist. DHPG increased the expression of cyclin D1, a key regulator of cell proliferation, and its nuclear translocation. DHPG also increased the expression of Bcl2A1, an antiapoptotic oncogene and simultaneously reduced the expression of Bax, a pro-apoptotic marker. Furthermore, the DHPG-induced proliferation of OCCM-30 cells was reduced by pretreatment with SB203580, SP600125, and PD98059, inhibitors of p38, JNK, and ERK1/2, respectively. Conclusions: These findings indicate that activation of mGluR1 expressed by OCCM-30 cells induces cell proliferation in a manner that is dependent on mitogen-activated protein kinase pathways and that cyclin D1 and Bcl2A1/Bax may be involved. Our results provide useful information for elucidating the mechanisms underlying cementum homeostasis and regeneration.