Physiological roles of mitogen-activated-protein-kinase-activated p38-regulated/activated protein kinase

Mitogen-activated protein kinases(MAPKs)are a family of proteins that constitute signaling pathways involved in processes that control gene expression,cell division, cell survival,apoptosis,metabolism,differentiation and motility.The MAPK pathways can be divided into conventional and atypical MAPK pathways.The first group converts a signal into a cellular response through a relay of three consecutive phosphorylation events exerted by MAPK kinase kinases,MAPK kinase,and MAPK.Atypical MAPK pathways are not organized into this three-tiered cascade.MAPK that belongs to both conventional and atypical MAPK pathways can phosphorylate both non-protein kinase substrates and other protein kinases.The latter are referred to as MAPK-activated protein kinases.This review focuses on one such MAPK-activated protein kinase,MAPK-activated protein kinase 5(MK5)or p38-regulated/activated protein kinase(PRAK).This protein is highly conserved throughout the animal kingdom and seems to be the target of both conventional and atypical MAPK pathways.Recent findings on the regulation of the activity and subcellular localization,bona fide interaction partners and physiological roles of MK5/PRAK are discussed.

Influence of Ren and Du meridian electro-acupuncture on neural stem cell proliferation and extracellular signal-regulated kinase pathway in a rat model of focal cerebral ischemia injury

BACKGROUND： Studies have shown that electro-acupuncture at the Ren meridian could improve proliferation of subventricular zone neural stem cells in cerebral-ischemic rats. However, there are few reports on the influence of electro-acupuncture at the Du meridian on neural stem cell proliferation. OBJECTIVE： To observe the influence of electro-acupuncture at Ren and Du meridians on neural stem cell proliferation in the subventricular zone and altered signal transduction in cerebral ischemia rats. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Laboratory of Human Anatomy, Medical College of Sun Yat-sen University from May 2006 to February 2008. MATERIALS： Mouse anti-rat bromodeoxyuridine （BrdU） monoclonal antibody was provided by Sigma, USA; mouse anti-rat nestin monoclonal antibody and extracellular signal-regulated protein kinase （ERK） specific inhibitor PD98059 were provided by Calbiochem, Germany; acupuncture needle was provided by Suzhou Acupuncture Supplies, China. METHODS： A total of 126 rats were randomly assigned to four groups： model （n = 36）, Du meridian （n = 36）, Ren/Du meridian （n = 36）, and Ren/Du meridian ＋ PD98059 （n = 18）. Rats in the Ren/Du meridian ＋ PD98059 group were observed on days 7 （n = 6） and 14 （n = 12） after cerebral ischemia injury. Rats in the model, Du meridian, and Ren/Du meridian groups were observed on days 7, 14, and 28 after cerebral ischemia injury, with 12 rats per group at each time point. Thread occlusion was used to establish middle cerebral artery occlusion models. Electro-acupuncture was performed at Renzhong （DU 26） and Baihui （DU 20） acupoints in the Du meridian group, as well as Chengjiang （RN 24）, Guanyuan （RN 4）, Renzhong, and Baihuiacupoints in the Ren/Du meridian and Ren/Du meridian ＋ PD98059 groups 2 days after model establishment. In addition, electro-acupuncture stimulation with disperse-dense waves was performed, with 30 Hz disperse wave, 100 Hz dense wave, and 5 V intensity for 20 minutes. Rats in the Ren/Du meridian ＋ PD98059 group were treated with 0.2 pg PD98059 injection into the subventricular zone, 2 pL per rat. Rats in the model group were not treated with electro-acupuncture. MAIN OUTCOME MEASURES： BrdU/nestin immunofluorescent staining was used to detect proliferating neural stem cells in the subventricular zone of cerebral ischemia rats; Western blot was used to determine phosphorylated ERK1 and 2 （pERK1/2） expression in the subventricular zone. RESULTS： On days 14 and 28 after cerebral ischemia, there were significantly more BrdU-positive and BrdU/nestin-positive cells in the Ren/Du meridian group compared with the Du meridian group （P 〈 0.05）. PD98059 decreased the number of BrdU-positive and BrdU/nestin-positive cells induced by electro-acupuncture at the/：ten and Du meridians （P 〈 0.05）. On days 7, 14, and 28 after treatment, pERK1/2 expression was significantly greater in the Du meridian and Ren/Du meridian groups compared with the model group （P 〈 0.05）. The promoting effect of electro-acupuncture at Ren and Du meridians on ERK1/2 phosphorylation was superior to electro-acupuncture at the Du meridian alone on day 14 after model induction （P 〈 0.05）. However, PD98059 completely abolished the promoting effect of electro-acupuncture at Ren/Du meridians on pERK1/2 expression （P 〈 0.05）. CONCLUSION： Electro-acupuncture at Ren and Du meridians increased proliferation of subventricular zone neural stem cells, which was related to activation of the ERK pathway in a rat model of cerebral ischemia injury.

XAF1 mediates apoptosis through an extracellular signal-regulated kinase pathway in colon cancer

Background:XIAP-associated factor 1(XAF1)negatively regulates the function of the X-linked inhibitor of apoptosis protein(XIAP),a member of the IAP family that exerts antiapoptotic effects.The extracellular signal-regulated kinase(ERK)pathway is thought to increase cell proliferation and to protect cells from apoptosis.The aim of the study was to investigate the correlation between the ERK1/2 signaling pathway and XAF1 in colon cancer.Methods:Four human colon cancer cell lines,HCT1116 and Lovo(wildtype p53),DLD1 and SW1116(mutant p53),were used.Lovo stable transfectants with XAF1 sense and antisense were established.The effects of dominant-negative MEK1(DN-MEK1)and MEK-specific inhibitor U0126 on the ERK signaling pathway and expression of XAF1 and XIAP proteins were determined.The transcription activity of core XAF1 promoter was assessed by dual luciferase reporter assay.Cell proliferation was measured by MTT assay.Apoptosis was determined by Hoechst 33258 staining.Results:U0126 increased the expression of XAF1 in a time-and dose-dependent manner.A similar result was obtained in cells transfected with DN-MEK1 treatment.Conversely,the expression of XIAP was down-regulated.Activity of the putative promoter of the XAF1 gene was significantly increased by U0126 treatment and DN-MEK1 transient transfection.rhEGF-stimulated phosphorylation of ERK appeared to have little or no effect on XAF1 expression.Overexpression of XAF1 was more sensitive to U0126-induced apoptosis,whereas down-regulation of XAF1 by antisense reversed U0126-induced inhibition of cell proliferation.Conclusions:XAF1 expression was up-regulated by inhibition of the ERK1/2 pathway through transcriptional regulation,which required de novo protein synthesis.The results suggest that XAF1 mediates apoptosis induced by the ERK1/2 pathway in colon cancer.

Increased expression of mitogen-activated protein kinase and its upstream regulating signal in human gastric cancer

AIM: To investigate the expression of mitogen-activated protein kinases (MAPKs) and its upstream protein kinase in human gastric cancer and to evaluate the relationship between protein levels and clinicopathological parameters.METHODS: Westem blot was used to measure the expression of extracellular signal-regulated kinase (ERK)-1, ERK-2, ERK-3,p38 and mitogen or ERK activated protein kinaseMEK-1proteins in surgically resected gastric carcinoma, adjacent normal mucosa and metastatic lymph nodes from 42 patients.Immunohistochemistry was employed for their localization.RESULTS: Compared with normal tissues, the protein levels of ERK-1 (integral optical density value 159 526±65 760 vs122 807±65 515, P = 0.001), ERK-2 (168 471±95 051 vs120 469±72 874, P＜0.001), ERK-3 (118 651±71 513 vs70 934±68 058, P＜0.001), P38 (104 776±51 650 vs82 930±40 392, P= 0.048) and MEK-1(116 486±45 725 vs101 434±49 387, P = 0.027) were increased in gastric cancer tissues. Overexpression of ERK-3 was correlated to TNM staging [average ratio of integral optic density (IOD)tumor:IODnormal in TNM Ⅰ, Ⅱ, Ⅲ, Ⅳ tumors was 1.43±0.34,5.08±3.74, 4.99±1.08, 1.44±1.02, n = 42, P = 0.023] and serosa invasion (4.31±4.34 vs 2.00±2.03, P = 0.037). In poorly differentiated cancers (n = 33), the protein levels of ERK-1 and ERK-2 in stage Ⅲ and Ⅳ tumors were higher than those in stage Ⅰ and Ⅱ tumors (2.64±3.01 vs 1.01±0.33,P = 0.022; 2.05±1.54 vs 1.24±0.40, P = 0.030). Gastric cancer tissues with either lymph node involvement (2.49±2.91vs 1.03±0.36, P= 0.023; 1.98±1.49 vs 1.24±0.44, P= 0.036)or serosa invasion (2.39±2.82 vs 1.01±0.35, P = 0.022;1.95±1.44 vs 1.14±0.36, P = 0.015) expressed higher protein levels of ERK-1 and ERK-2. In Borrmann Ⅱ tumors,expression of ERK-2 and ERK-3 was increased compared with Borrmann Ⅲ tumors (2.57±1.86 vs 1.23±0.60, P = 0.022;5.50±5.05 vs 1.83±1.21, P = 0.014). Borrmann Ⅳ tumors expressed higher p38 protein levels. No statistically significant difference in expression of MAPKs was found when stratified to tumor size or histological grade (P＞0.05).Protein levels of ERK-2, ERK-3 and MEK-1 in metastatic lymph nodes were 2-7 folds higher than those in adjacent normal mucosa. The immunohistochemistry demonstrated that ERK-1, ERK-2, ERK-3, p38 and MEK-1 proteins were mainly localized in cytoplasm. The expression of MEK-1 in gastric cancer cells metastasized to lymph nodes was higher than that of the primary site.CONCLUSION: MAPKs, particularly ERK subclass are overexpressed in the majority of gastric cancers.Overexpression of ERKs is correlated to TNM staging, serosa invasion, and lymph node involvement. The overexpression of p38 most likely plays a prominent role in certain morphological subtypes of gastric cancers. MEK-1 is also overexpressed in gastric cancer, particularly in metastatic lymph nodes. Upregulation of MAPK signal transduction pathways may play an important role in tumorigenesis and metastatic potential of gastric cancer.

Hepatitis B virus X protein up-regulates tumor necrosis factor-α expression in cultured mesangial cells via ERKs and NF-κB pathways

Objective:To investigate the effects of hepatitis B virus(HBV)X protein(HBx)on the expression of tumor necrosis factor-α(TNF-α)in glomerular mesangial cells(GMCs)and the underlying intracellular signal pathways.Methods:The plasmid pCI-neo-X that carries the X gene of hepatitis B virus was transfected into cultured GMCs.HBx expression in the transfected GMCs was assessed by Western-blot.TNF-αprotein and mRNA were assessed by ELISA and semi-quantitative RT-PCR,respectively.Three kinase inhibitors-U0126,an inhibitor of extracellular signal-regulated kinases(ERKs);lactacvstin,an inhibitor of nuclear factor-κB(NF-κB);and SB203580,a selective inhibitor of p38 MAP kinase(p38 MAPK)were used to determine which intracellular signal pathways may underlie the action of HBx on TNF-αexpression in transfected GMCs.Results:A significant increase in HBx expression in pCI-neo-X transfected GMCs was detected at 36 h and 48 h,which was not affected by any of those kinase inhibitors mentioned above.A similar increase in the expression of both TNF-αprotein and mRNA was also observed at 36 h and 48 h,which was significantly decreased in the presence of U0126 or lactacytin,but not SB203580.Conclusions:HBx upregulates TNF-αexpression in cultured GMCs,possibly through ERKs and NF-κB pathway,but not p38 MAPK pathway.

Role of ERK-MAPK signaling pathway in pentagastrin-regulated growth of large intestinal carcinoma

AIM:To explore the role and mechanisms of extracellular signal-regulated protein kinase-mitogen-activated protein kinase(ERK-MAPK) signaling in pentagastrinregulated growth of large intestinal carcinoma.METHODS:HT-29 cells were incubated in different media and divided into the control group,pentagastrin group,proglumide group,and pentagastrin + proglumide group.No reagent was added to the control group,and other groups were incubated with reagent at different concentrations.Changes in proliferation of HT-29 cells were detected by MTT assay,and the optimal concentrations of pentagastrin and proglumide were determined.The changes in proliferation index(PI) and apoptosis rate(AR) of HT-29 cells were detected by Annexin V-fluorescein isothiocyanate flow cytometry.mRNA expression of pentagastrin receptor/cholecystokinin-B receptor(CCK-BR),ERK1/2 and K-ras were detected by reverse transcriptase polymerase chain reaction.The protein and phosphorylation level of ERK1/2 and K-ras were detected by western blotting.All data were analyzed by analysis of variance and SNK-q test.RESULTS:The proliferation of HT-29 cells was stimulated by pentagastrin at a concentration of 6.25-100 mg/L,and the optimal concentration of pentagastrin was 25.0 mg/L(F = 31.36,P < 0.05).Proglumide had no obvious effect on the proliferation of HT-29 cells,while it significantly inhibited the proliferation of HT-29 cells stimulated by pentagastrin when the concentration of proglumide was 8.0-128.0 mg/L,and the optimal concentration was 32.0 mg/L(F = 24.31,P < 0.05).The PI of the pentagastrin(25.0 mg/L) group was 37.5% ± 5.2%,which was significantly higher than 27.7% ± 5.0% of the control group and 27.3% ± 5.8% of the pentagastrin(25.0 mg/L) + proglumide(32.0 mg/L) group(Q = 4.56-4.75,P < 0.05).The AR of the pentagastrin(25.0 mg/L) group was 1.9% ± 0.4%,which was significantly lower than 2.5% ± 0.4% of the control group and 2.4% ± 0.3% of the pentagastrin(25.0 mg/L) + proglumide(32.0 mg/L) group(Q = 4.23-4.06,P < 0.05).mRNA expression of CCK-BR was detected in HT-29 cells.The phosphorylation levels of ERK1/2 protein and phosphorylated K-ras protein of the pentagastrin group were 0.43% ± 0.04% and 0.45% ± 0.06%,which were significantly higher than 0.32% ± 0.02% and 0.31% ± 0.05% of the control group(Q = 7.78-4.95,P < 0.05),and 0.36% ± 0.01% and 0.35% ± 0.04% of the pentagastrin + proglumide group(Q = 5.72-4.08,P < 0.05).There were no significant differences in the mRNA and protein expression of ERK1/2 and K-ras among the control,pentagastrin,proglumide and pentagastrin + proglumide groups(F = 0.52,0.72,0.78,0.28;P > 0.05).CONCLUSION:Gastrin stimulates proliferation of HT-29 cells and inhibits apoptosis by upregulating phosphorylation of ERK and K-ras through the Ras-Raf-MEK1/2-ERK1/2 pathway,and this is restrained by proglumide.

Protein tyrosine phosphatase 1B regulates migration of ARPE-19 cells through EGFR/ERK signaling pathway

AIMTo evaluate whether protein tyrosine phosphatase 1B (PTP1B) contributed to initiate human retinal pigment epithelium cells (A)-19 migration and investigate the signaling pathways involved in this process.METHODSARPE-19 cells were cultured and treated with the siRNA-PTP1B. Expression of PTP1B was confirmed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). AG1478 [a selective inhibitor of epidermal growth factor receptor (EGFR)] and PD98059 (a specific inhibitor of the activation of mitogen-activated protein kinase) were used to help to determine the PTP1B signaling mechanism. Western blot analysis verified expression of EGFR and extracellular signal-regulated kinase (ERK) in ARPE-19 cells. The effect of siRNA-PTP1B on cell differentiation was confirmed by immunostaining for &#x003b1;-smooth muscle actin (&#x003b1;-SMA) and qRT-PCR. Cell migration ability was analyzed by transwell chamber assay.RESULTSThe mRNA levels of PTP1B were reduced by siRNA-PTP1B as determined by qRT-PCR assay. SiRNA-PTP1B activated EGFR and ERK phosphorylation. &#x003b1;-SMA staining and qRT-PCR assay demonstrated that siRNA-PTP1B induced retinal pigment epithelium (RPE) cells to differentiate toward better contractility and motility. Transwell chamber assay proved that PTP1B inhibition improved migration activity of RPE cells. Treatment with AG1478 and PD98059 abolished siRNA-PTP1B-induced activation of EGFR and ERK, &#x003b1;-SMA expression and cell migration.CONCLUSIONPTP1B inhibition promoted myofibroblast differentiation and migration of ARPE-19 cells, and EGFR/ERK signaling pathway played important role in migration process.

基于MAPK/ERK通路探讨茯苓多糖对卵巢早衰模型大鼠的作用及其分子机制

目的基于丝裂原活化蛋白激酶/细胞外调节蛋白激酶(MAPK/ERK)通路探讨茯苓多糖对卵巢早衰(POF)模型大鼠的作用及其分子机制。方法取50只SD雌性大鼠腹腔注射环磷酰胺诱导复制POF模型,随机分为5组:模型组、茯苓多糖低剂量组(100 mg/kg)、茯苓多糖高剂量组(200 mg/kg)、茴香霉素组(MAPK激活剂,10 mg/kg)、茯苓多糖高剂量+茴香霉素组,每组10只;另取10只SD雌性大鼠腹腔注射等剂量生理盐水作为对照组。分组处理后分别测定各组大鼠子宫指数及卵巢指数;酶联免疫吸附试验(ELISA)测定各组大鼠血清性激素[雌二醇(E2)、促黄体生成素(LH)、卵泡刺激素(FSH)]水平;HE染色观察各组大鼠卵巢形态;酶联免疫吸附试验检测各组大鼠血清及卵巢组织肿瘤坏死因子-α(TNF-α)、白细胞介素-4(IL-4)、白细胞介素-18(IL-18)水平;Western blotting检测各组大鼠卵巢组织MAPK/ERK通路相关蛋白表达。结果与对照组比较,模型组大鼠卵巢间质结构有一定程度的出血和纤维化损伤,卵泡发育失常,血清FSH和LH水平、血清和卵巢组织TNF-α、IL-4、IL-18水平、卵巢组织p-p38 MAPK/p38 MAPK及p-ERK1/2/ERK1/2相对表达量均升高(P<0.05),子宫指数和卵巢指数、E_(2)水平均降低(P<0.05)。与模型组比较,茯苓多糖低剂量组、茯苓多糖高剂量组大鼠卵巢形态损伤及卵泡发育失常均减轻,血清FSH及LH水平、血清和卵巢组织TNF-α、IL-4、IL-18水平、卵巢组织p-p38 MAPK/p38 MAPK及p-ERK1/2/ERK1/2相对表达量均降低(P<0.05),子宫指数和卵巢指数、E_(2)水平均升高(P<0.05),且茯苓多糖高剂量组效果更优(P<0.05)。茴香霉素组大鼠卵巢形态损伤及卵泡发育失常加重,血清FSH及LH水平、血清和卵巢组织TNF-α、IL-4、IL-18水平、卵巢组织p-p38 MAPK/p38 MAPK及p-ERK1/2/ERK1/2相对表达量均升高(P<0.05),子宫指数及卵巢指数、E_(2)水平均降低(P<0.05)。茯苓多糖高剂量+茴香霉素组逆转茯苓多糖作用,呈相反趋势(P<0.05)。结论茯苓多糖可通过抑制MAPK/ERK通路的激活减轻POF大鼠炎症,从而改善其卵巢功能和性激素分泌,缓解大鼠POF症状。

SOX7靶向ERK1/2/PD-L1通路抑制结直肠癌血管生成

目的探讨性别决定区Y框蛋白7(SOX7)对结直肠癌血管生成的影响及潜在作用机制。方法应用免疫荧光检测结直肠癌患者组织样本中SOX7表达水平,之后通过裸鼠、转染SOX7 mimic的人结直肠癌细胞系SW480细胞和人脐静脉内皮细胞(HUVEC)共培养进一步研究。用Western-blot验证SOX7与ERK1/2/PD-L1对结直肠癌细胞的相关蛋白表达的影响。用CCK8检测SOX7与ERK1/2/PD-L1对HUVEC增殖的影响。通过体外内皮细胞成管实验测定SOX7与ERK1/2/PD-L1对肿瘤血管生成的影响。结果SOX7在人结直肠癌组织中表达被抑制(P<0.01),同时SOX7的过表达抑制了小鼠体内肿瘤生长(P<0.01)。SW480细胞中SOX7的过表达抑制了ERK1/2、c-Jun的表达,并在ERK1/2的激动剂Senkyunolide I的作用下上调了SW480细胞的ERK1/2、c-Jun蛋白表达(P<0.01),逆转了SOX7对SW480细胞中ERK1/2、c-Jun蛋白表达的影响(P<0.01)。HUVEC中SOX7抑制了PD-L1、V-EGFR2、p-PI3K、HIF-1α的蛋白表达,Senkyunolide I上调了HUVEC的PD-L1、V-EGFR2、p-PI3K、HIF-1α的蛋白表达,并逆转了SOX7对HUVEC中上述相关蛋白表达的影响(P<0.01)。PD-1/PD-L1 Inhibitor 3抑制了PD-L1、V-EGFR2、p-PI3K、HIF-1α的蛋白表达,SOX7过表达在PD-1/PD-L1 Inhibitor 3的影响下并没有表现出抑制作用。CCK8实验结果显示SOX7过表达显著抑制了HUVEC的增殖能力,Senkyunolide I作用下的两组HUVEC增殖能力较SOX7 NC组与SOX7 mimic组明显上升,PD-1/PD-L1 Inhibitor 3作用下的两组HUVEC增殖能力较SOX7 NC组与SOX7 mimic组明显下降,以上均有明显统计学差异(P<0.01)。成管实验结果显示SOX7过表达抑制了HUVEC的血管生成,Senkyunolide I强烈加速了血管生成,而PD-1/PD-L1 Inhibitor 3血管生成则被显著抑制,以上均有明显统计学差异(P<0.01)。结论SOX7通过ERK1/2/PD-L1通路抑制结直肠肿瘤的增殖和血管生成,SOX7可能是晚期CRC患者临床治疗中潜在的抗血管生成靶点。

二甲双胍调节MEK/ERK通路及基质金属蛋白酶在恶性肿瘤中应用的研究进展

二甲双胍是目前治疗2型糖尿病的一线用药,其通过改善胰岛素抵抗、抑制肝脏糖异生等途径降低血糖。近年发现,二甲双胍还可通过促分裂原活化的蛋白激酶激酶/胞外信号调节激酶信号通路以及基质金属蛋白酶诱导细胞周期停滞、促进细胞凋亡、抑制细胞侵袭迁移,并可与各种抗肿瘤药物联用发挥协同作用以抑制肿瘤进展。但目前仍缺乏二甲双胍可以抑制癌症患者病情进展的研究证据,未来还需要对二甲双胍在恶性肿瘤治疗中的作用及其有效性、安全性进行进一步研究。

富含半胱氨酸和甘氨酸蛋白2在神经母细胞瘤恶性进展中的功能和机制

目的:探究富含半胱氨酸和甘氨酸蛋白2(cysteine and glycine-rich protein 2,CSRP2)在神经母细胞瘤(neuroblastoma,NB)恶性进展中的功能和作用机制。方法:利用R2数据库分析NB临床样本中CSRP2基因的mRNA水平与NB患儿临床预后的相关性;在NB细胞系SK-N-BE(2)和SH-SY5Y中利用靶向小干扰RNA(small interfering RNA,siRNA)干扰CSRP2的表达或利用质粒转染过表达CSRP2;通过结晶紫染色和实时无标记动态细胞分析技术观察NB细胞的增殖情况;采用克隆形成方法观察NB细胞长时间的克隆形成能力;利用免疫荧光实验检测细胞增殖标记物Ki-67的水平;利用碘化丙啶(propidium iodide,PI)染色流式细胞术分析细胞周期比例,Annexin V/7AAD染色分析细胞凋亡比例;采用划痕实验观察细胞的迁移能力;利用Western blot或实时荧光定量PCR(quantitative real-time PCR,RT-qPCR)检测NB原发肿瘤组织和细胞系中蛋白和基因的表达水平。结果:NB临床数据库中,国际神经母细胞瘤分期(international neuroblastoma staging system,INSS)为高危险度3/4期的NB组织中CSRP2的mRNA水平显著高于低危险度的1/2期,且高表达水平组NB患儿的生存期显著低于低表达组;Western blot结果显示,CSRP2在3/4期NB组织中的蛋白水平显著高于1/2期。NB细胞中敲低CSRP2,细胞的活力减弱、增殖能力降低;NB细胞中过表达CSRP2促进细胞增殖;敲低CSRP2后,sub-G1、G0/G1和S期细胞的比例增加,Annexin V阳性细胞的比例增多;敲低CSRP2的NB细胞的划痕愈合率显著小于对照组。机制研究发现,敲低CSRP2后细胞增殖标记分子Ki-67和细胞外信号调节激酶1/2(extracellular signal-regulated kinases 1/2,ERK1/2)磷酸化水平显著低于对照组。结论:CSRP2在高危险度3/4期NB组织中高表达,表达水平与NB患儿生存期呈负相关;CSRP2通过促进ERK1/2活化,促进NB细胞的增殖和迁移,抑制细胞凋亡,表明CSRP2通过激活ERK1/2促进NB进展,为高危NB的靶向治疗提供了潜在的靶点。

复方芩柏汤调控ERK/JNK信号通路治疗溃疡性结肠炎的效应及机制研究

目的 研究复方芩柏汤对细胞外信号调节激酶(extracellular regulated protein kinases, ERK)/c-Jun氨基末端激酶(cJun N-terminal kinase, JNK)信号通路的调控作用,以及对溃疡性结肠炎(ulcerative colitis, UC)小鼠血清中炎症因子的影响。方法 将60只SPF级健康雄性BALB/C小鼠利用3%葡聚糖硫酸(dextran sulfate sodium, DSS)建立UC模型,造模成功后随机分为模型组(以生理盐水灌肠)、美沙拉嗪组(以0.196 g/kg美沙拉嗪药液灌肠)、复方芩柏汤组(以1.092 g/kg复方芩柏颗粒剂药液灌肠),每组20只,每天保留灌肠2次,连续3周。另取20只正常饲养小鼠作为空白组。在治疗前和治疗后第7、14、21天,观察小鼠体质量、大便性状、便血情况,并计算疾病活动指数(disease activity index, DAI),且于给药结束后进行麻醉取血并取结肠组织。采用HE染色观察各组小鼠结肠组织病理变化情况;ELISA法检测各组小鼠血清中炎症因子白细胞介素(interleukin)-22、IL-6、IL-10、肿瘤坏死因子-α(tumor necrosis factor-α, TNF-α)含量变化情况;采用Western blot法检测各组小鼠结肠组织中的p90核糖体蛋白S6激酶(p90 ribosomal protein S6 kinase, p90RSK)、JNK、磷酸化c-Jun氨基末端激酶(phosphorylated c-Jun N-terminal kinase, p-JNK)、细胞外调节蛋白激酶1/2(extracellular regulated protein kinases 1/2, ERK 1/2)、磷酸化细胞外调节蛋白激酶1/2(phospho extracellular regulated protein kinases, p-ERK 1/2)蛋白的表达。结果 在治疗的第7、14、21天,美沙拉嗪组、复方芩柏汤组小鼠体质量均明显高于模型组(P<0.05,P<0.01),DAI评分明显低于模型组(P<0.05,P<0.01)。光镜下,与模型组相比,美沙拉嗪组及复方芩柏汤组小鼠结肠组织病理改变呈不同程度的恢复,炎症浸润减轻。给药结束后,与空白组比较,模型组p90RSK、p-JNK、p-ERK 1/2蛋白以及IL-6、TNF-α蛋白表达明显升高(P<0.01);与模型组比较,美沙拉嗪组和复方芩柏汤组p90RSK、p-JNK、p-ERK 1/2蛋白以及IL-6、TNF-α蛋白表达明显降低(P<0.05,P<0.01),抗炎因子IL-22、IL-10含量明显升高(P<0.01)。结论 复方芩柏汤可能通过抑制ERK/JNK信号通路,促进抗炎因子IL-22、IL-10的表达,抑制促炎因子IL-6、TNF-α的表达,减少肠道炎症反应,促进肠上皮细胞增殖,改善肠黏膜屏障,促进UC小鼠肠道黏膜组织损伤修复。

不同级别胶质瘤患者MEK、ERK、CHKα蛋白的阳性表达情况及临床意义

目的探讨不同级别胶质瘤患者胆碱激酶α(CHKα)、细胞外信号调节激酶(ERK)及丝裂原激活蛋白激酶(MEK)蛋白的阳性表达情况及临床意义。方法回顾性分析2019年1月至2022年12月长沙市第四医院神经外科收治的124例胶质瘤患者的临床资料。检测、统计不同级别胶质瘤患者MEK、ERK、CHKα蛋白的阳性表达情况。结果不同肿瘤最大径、年龄、WHO分级及预后胶质瘤患者MEK、ERE、CHKα蛋白的高、低表达情况比较,差异均有统计学意义(P<0.05)。Ⅰ、Ⅱ、Ⅲ、Ⅳ级胶质瘤患者MEK蛋白阳性表达率分别为9.62%、7.69%、94.08%和92.04%,ERK蛋白阳性表达率分别为9.57%、7.49%、94.52%和92.18%,CHKα蛋白阳性表达率分别为9.60%、7.53%、94.71%和92.23%,高、低级别胶质瘤患者MEK、ERK、CHKα蛋白阳性表达率比较,差异均有统计学意义(P<0.05)。随访结束后结果显示,124例患者中死亡52例,失访12例,获得随访112例,随访率为90.32%。结论不同级别胶质瘤患者MEK、ERK、CHKα蛋白的阳性表达情况有明显区别,并且与患者的疾病预后明显相关,对疾病的诊断和预后判断具有重要价值。

赤凤迎源针刺法对面神经损伤模型大鼠Ras/MEK/ERK信号通路的影响

目的探讨赤凤迎源针刺法对面神经超微结构、丝裂原活化的细胞外信号调节激酶(mitogen-activated extracellular signal-regulated kinase,MEK)、细胞外信号调节蛋白激酶(extracellular signal-regulated kinase,ERK)及血清KRas蛋白表达的影响。方法将SD大鼠随机分为空白对照组、模型组、常规针刺组、赤凤迎源针刺组,每组8只。除空白对照组大鼠正常饲养外,其他各组大鼠用面神经颊支压榨法诱导面神经损伤模型。造模成功后,予以干预2周。干预结束后,行电镜检查观察大鼠的面神经超微结构;通过HE染色观察面神经组织形态组织学变化;ELISA法检测血清KRas的表达水平;Western blot检测面神经组织MEK、ERK蛋白的表达水平。结果造模后,与空白对照组比较,另外3组大鼠动物行为学评分均明显升高(P<0.01)。针刺2周后,常规针刺组及赤凤迎源针刺组大鼠评分明显低于模型组(P<0.01),且赤凤迎源针刺组评分低于常规针刺组(P<0.01)。针刺2周后,与模型组对比,常规针刺组及赤凤迎源针刺组面神经轴突纤维排列较紧密,内质网较多,KRas蛋白表达明显升高(P<0.05),面神经MEK蛋白、ERK蛋白表达升高(P<0.05),且赤凤迎源针刺组均高于常规针刺组(P<0.05)。结论赤凤迎源针刺法可改善面神经损伤模型大鼠动物行为学,上调KRas、MEK及ERK表达水平,可能与激活Ras/MEK/ERK信号通路有关,从而修复面神经损伤。

异钩藤碱对大鼠急性胰腺炎细胞的炎症和凋亡改善及ERK信号通路调控作用

目的观察异钩藤碱(LSO)对大鼠急性胰腺炎(AP)细胞炎症和凋亡改善及ERK信号通路调控作用。方法将AR42J细胞分为6组,对照组正常培养,模型组、LSO组、抑制剂组、LSO+抑制剂组、LSO+激活剂组加入100 nmol/L雨蛙素制备AP细胞模型,LSO组制模后加入40μmol/L LSO,抑制剂组制模后加入10μmol/L U0126,LSO+抑制剂组制模后加入40μmol/L LSO和10μmol/L U0126,LSO+激活剂组制模后加入40μmol/L LSO和0.1μmol/L C16-PAF。采用ELISA法、EdU法及Hoechst 33258染色法分别测定细胞培养液中的炎症因子(TNF-α、IL-6、IL-8、IL-1β)、细胞增殖率和凋亡率,qPCR法测定细胞中NLRP3、斑点样蛋白(ASC)、半胱氨酸蛋白酶-1(Caspase-1)mRNA,WB法测定细胞中ERK 1/2、p-ERK 1/2、NLRP3、ASC、Caspase-1蛋白。结果与对照组比较,模型组细胞TNF-α、IL-6、IL-8、IL-1β、凋亡率、p-ERK 1/2蛋白及NLRP3、ASC、Caspase-1 mRNA和蛋白升高,增殖率降低(P均<0.05);与模型组比较,LSO组、抑制剂组细胞炎症因子(TNF-α、IL-6、IL-8、IL-1β)、凋亡率、p-ERK 1/2蛋白及NLRP3、ASC、Caspase-1 mRNA和蛋白降低,增殖率升高(P均<0.05);与LSO组比较,LSO+抑制剂组中U0126增强了LSO对细胞上述指标趋势的作用,而LSO+激活剂组中C16-PAF则逆转了LSO对细胞上述指标趋势的作用(P均<0.05)。结论LSO对大鼠急性胰腺炎细胞的炎症和凋亡有改善作用,可能通过调控ERK信号通路来实现。

基于EGFR/MAPK/ERK信号通路探讨鳖甲煎丸对MHCC-97H肝癌细胞皮下瘤的抑瘤作用

目的基于表皮生长因子受体(epidermal growth factior receptor,EGFR)/丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)/细胞外信号调节激酶(extracellular signal-regulated kinase,ERK)信号通路探究鳖甲煎丸对MHCC-97H肝癌细胞皮下瘤的抑瘤作用及作用机制。方法选取30只雄性BLAB/c裸鼠,建立MHCC-97H肝癌细胞皮下瘤模型。造模成功后随机分为模型组,鳖甲煎丸低、中、高剂量组(0.55、1.1、2.2 g/kg),西药组(乐伐替尼4 mg/kg+吉非替尼80 mg/kg),每组6只。鳖甲煎丸低、中、高剂量组灌胃2次/d,西药组每周灌胃5 d,模型组予以等量生理盐水2次/d灌胃,每组连续干预2周。观察大鼠一般情况;计算各组大鼠抑瘤率;HE染色观察病理形态学变化;RT-qPCR检测瘤体组织中EGFR、丝裂原活化蛋白质激酶激酶(mitogen-activated protein kinase kinase,MEK)、ERK1、ERK2 mRNA表达水平;Western blot检测EGFR、磷酸化的EGFR(p-EGFR)、MEK、磷酸化的MEK(p-MEK)、ERK1、ERK2、磷酸化的ERK1/2(p-ERK1/2)、基质金属蛋白酶-1(matrix metalloproteinase-1,MMP-1)、细胞周期蛋白D1(cell cycle protein D1,Cyclin D1)、神经型钙黏附蛋白(N-cadherin)、上皮型钙黏附蛋白(E-cadherin)相对表达水平。结果与模型组比较,鳖甲煎丸低、中、高剂量组及西药组精神、反应、进食饮水等情况均明显改善。与第0天比较,各组第14天体质量明显降低(P<0.01)。与模型组、鳖甲煎丸低剂量组比较,鳖甲煎丸中、高剂量组和西药组瘤体质量减轻(P<0.05,P<0.01)。鳖甲煎丸低、中、高剂量组和西药组抑瘤率分别为20%、47.73%、55.91%、75.45%。与模型组比较,鳖甲煎丸低、中、高剂量组及西药组肿瘤细胞排列疏松,边界模糊,细胞核固缩、破裂,其中西药组最明显。与模型组比较,鳖甲煎丸低、中、高剂量组和西药组EGFR、MEK、ERK1、ERK2 mRNA表达水平明显下降(P<0.01);与鳖甲煎丸低剂量组比较,鳖甲煎丸高剂量组和西药组EGFR、MEK、ERK1、ERK2 mRNA表达水平显著降低(P<0.01),鳖甲煎丸中剂量组ERK1 mRNA表达水平显著降低(P<0.01);与鳖甲煎丸中剂量组比较,西药组EGFR、ERK2 mRNA表达水平降低(P<0.05,P<0.01)。与模型组比较,鳖甲煎丸中、高剂量组和西药组p-EGFR/EGFR、p-MEK/MEK、p-ERK1/ERK1、p-ERK2/ERK2、MMP-1、Cyclin D1、N-cadherin蛋白相对表达水平下降(P<0.05,P<0.01),E-cadherin蛋白相对表达水平明显升高(P<0.01)。与鳖甲煎丸高剂量组比较,西药组p-EGFR/EGFR、p-ERK1/ERK1、MMP-1、Cyclin D1、N-cadherin蛋白相对表达水平明显下降(P<0.01),E-cadherin蛋白相对表达水平升高(P<0.05)。结论鳖甲煎丸可能通过抑制EGFR/MAPK/ERK信号通路激活,从而下调MMP-1、Cyclin D1、N-cadherin蛋白,上调E-cadherin蛋白表达,进而对MHCC-97H肝癌细胞皮下瘤产生显著的抑制作用。

哈蟆油酶解物激活MAPK/ERK信号凋亡途径修复皮质酮诱导HT-22细胞损伤作用

为研究哈蟆油(Oviductus Ranae,OR)对海马神经元细胞保护作用机制,该研究通过皮质酮(Corticosterone,CORT)诱导HT-22细胞损伤模型探究哈蟆油酶解物对小鼠海马神经元细胞(HT-22)细胞损伤模型的保护作用及其作用机制。采用CORT与HT-22细胞共同培养建立HT-22细胞损伤模型,给予哈蟆油酶解物再次孵育,将ERK信号通路抑制剂PD98059加入HT-22细胞中。采用MTT法、Hochest 33258染色、流式细胞术、Western blot技术检测HT-22细胞凋亡情况和相关蛋白表达以及MAPK/ERK信号通路蛋白表达。结果显示高水平CORT能够诱导HT-22细胞损伤,哈蟆油酶解物能够使CORT诱导的HT-22细胞活力提升62.5%~87.5%,凋亡比例降低50%~70%。哈蟆油酶解物能够上调BCL-2、P-ERK1/2蛋白表达,同时下调BAX、Caspase-3、Caspase-9的蛋白表达。上述结果表明,高水平CORT是通过抑制MAPK/ERK信号通路促进凋亡的发生从而诱导HT-22细胞损伤,哈蟆油酶解物能够通过激活MAPK/ERK信号通路调节BLC-2、BAX、Caspase-3、Caspase-9凋亡相关蛋白的表达进而抑制凋亡的发生减轻神经元损伤,该作用机制为哈蟆油发挥抗抑郁作用的关键途径之一。

盐酸安罗替尼联合化疗对宫颈癌患者癌组织血管新生能力及MEK/ERK通路的影响

目的研究盐酸安罗替尼联合化疗对宫颈癌患者癌组织血管新生能力及MEK/ERK通路的影响。方法选取苏州大学附属第二医院2020年8月—2022年8月收治的68例宫颈癌患者为研究对象,采用随机数字表法分为试验组(n=34)和对照组(n=34)。对照组接受常规化疗治疗,试验组在此基础上联合安罗替尼抗血管生成治疗。对比两组患者临床疗效,治疗前后血管新生能力[血管内皮生长因子(VEGF)、肿瘤微血管密度(MVD)],治疗后MEK/ERK通路分子水平。结果与对照组总有效率58.82%(20/34)相比,试验组88.23%(30/34)更高(χ^(2)=7.555,P<0.05);治疗后,两组患者VEGF、MVD水平均降低,且相比于对照组,试验组更低[对照组分别为(63.98±5.14)ng·g^(-1)、(13.02±1.65)个·mm^(-2),试验组分别为(48.06±5.35)ng·g^(-1)、(6.68±1.62)个·mm^(-2)](t=12.512、15.987,均P<0.05);与对照组患者相比,试验组患者MEK1、MEK2以及ERK1/2水平更低[对照组分别为(2.06±0.19)ng·mL^(-1)、(2.28±0.14)ng·mL^(-1)、(1.48±0.12)ng·mL^(-1),试验组分别为(1.23±0.21)ng·mL^(-1)、(1.06±0.15)ng·mL^(-1)、(0.84±0.11)ng·mL^(-1)](t=17.089、34.670、22.924,均P<0.05)。结论盐酸安罗替尼联合化疗能够有效抑制宫颈癌患者癌组织血管新生能力以及MEK/ERK通路分子水平,临床疗效较高。

丝裂原活化蛋白激酶/细胞外调节蛋白激酶通路在动静脉内瘘术后内膜增生部位血管组织和细胞中的表达及意义

目的探讨丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)/细胞外调节蛋白激酶(extracellular signal-regulated kinase,ERK)通路在动静脉内瘘术后内膜增生部位血管组织中的表达及意义,初步探索抑制MAPK/ERK通路对肌成纤维细胞自噬及增殖过程的影响。方法选取2023年1月至3月期间在海南医学院第一附属医院肾内科行动静脉内瘘重建术的患者6例,观察组收集动静脉内瘘重建术患者内膜增生严重部位的静脉血管组织,对照组为重建术中需结扎的侧支正常静脉组织。术前收集患者的一般资料,超声测量拟切取部位血管内径及内膜厚度,蛋白质印迹法检测血管组织中磷酸化细胞外调节蛋白激酶(phosphorylation-extracellular regulat-ed protein kinases 1/2,p-ERK1/2)、B细胞淋巴瘤/白血病-2蛋白相互作用蛋白1(myosin-like B cell lymphoma/lewkmia-2 interacting protein1,Beclin^(-1))、增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)蛋白的表达水平,并分析其与静脉内膜厚度的相关性。以肌成纤维细胞为研究对象,尿毒症血清培养,并予ERK1/2抑制剂去氢钩藤碱(Corynoxeine)干预,提取细胞总蛋白及RNA,蛋白质印迹法及实时定量PCR检测Beclin^(-1)及PCNA的表达变化。结果入组患者透析过程中均存在血流量不足,灰阶超声提示动静脉内瘘狭窄处静脉内膜明显增厚[(0.143±0.014)cm比(0.097±0.016)cm],血管腔内径为(0.166±0.028)cm。蛋白质印迹法结果显示,与正常侧支部位血管组织相比较,内膜严重增生部位血管组织中p-ERK1/2、Beclin^(-1)、PCNA蛋白的表达明显增加,差异有统计学意义(均P<0.05)。观察组静脉内膜厚度与p-ERK1/2、Beclin^(-1)、PCNA蛋白的表达水平均呈正相关(R2=0.929、0.702、0.789,均P<0.05)。在细胞模型上,与正常对照组相比较,尿毒症血清组自噬相关指标Beclin^(-1)及增殖相关指标PCNA的表达明显升高,差异有统计学意义(均P<0.05)。而加入ERK特异性抑制剂Corynoxeine后,Beclin^(-1)及PCNA的表达均明显减低,差异有统计学意义(均P<0.05)。结论MAPK/ERK通路参与了动静脉内瘘内膜增生过程,促进细胞自噬及增殖过程,抑制该通路活性,或可减低细胞自噬及增殖,从而减轻内膜增生。

异甘草素对七氟烷致老年大鼠骨折术后认知障碍的影响

目的观察异甘草素对七氟烷致老年大鼠骨折术后认知障碍的改善作用及对细胞外信号调节激酶1/2(extracellular signal-regulated kinase1/2,ERK1/2)/环磷酸腺苷反应单元结合蛋白(cyclic-AMP response element binding protein,CREB)/脑源性神经营养因子(brain derived neurotrophic factor,BDNF)通路的影响。方法将40只骨折大鼠随机分为对照组、模型组、异甘草素组、联合组,每组10只。联合组大鼠灌胃异甘草素(15 mg·kg^(−1)),腹腔注射PD98059(1 mg·kg^(−1));异甘草素组灌胃异甘草素(15 mg·kg^(−1)),腹腔注射等量二甲基亚砜(dimethyl sulfoxide,DMSO);对照组、模型组分别灌胃、腹腔注射等量DMSO。每日1次,持续5 d。用水迷宫实验检测大鼠认知功能;检测血清炎症因子肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)和白细胞介素-1β(interleukin-1β,IL-1β);Tunel染色法观察海马神经元凋亡情况;免疫印迹法检测海马组织ERK1/2、磷酸化ERK1/2(phospho-ERK1/2,p-ERK1/2)、CREB、p-CREB、BDNF蛋白的表达。结果与模型组[(36.26±3.95)s、(23.91±2.91)s、(5.17±0.68)次、(494.42±45.62)ng·mL^(−1)、(600.98±60.01)ng·mL^(−1)、(34.26%±3.96%)、(0.23±0.03)、(0.14±0.02)、(0.16±0.02)]比较,异甘草素组建模后逃避潜伏期缩短,第三象限停留时间延长,穿越原平台次数增加,血清TNF-α水平、IL-1β水平、海马神经元凋亡率降低,p-ERK1/2/ERK1/2、p-CREB/CREB及BDNF蛋白表达水平升高[(14.87±1.43)s、(45.08±4.54)s、(12.31±1.77)次、(253.41±27.61)ng·mL^(−1)、(229.04±23.55)ng·mL^(−1)、(8.53%±1.06%)、(0.66±0.11)、(0.51±0.05)、(0.60±0.07)],P<0.05;与异甘草素组比较,联合组建模后逃避潜伏期延长,第三象限停留时间缩短,穿越原平台次数减少,血清TNF-α水平、IL-1β水平、海马神经元凋亡率升高,p-ERK1/2/ERK1/2、p-CREB/CREB及BDNF蛋白的表达水平降低[(21.06±2.72)s、(37.17±3.10)s、(7.72±0.96)次、(346.91±44.67)ng·mL^(−1)、(391.38±34.75)ng·mL^(−1)、(16.11%±1.84%)、(0.42±0.05)、(0.29±0.03)、(0.24±0.03)],P<0.05。结论异甘草素可改善术后认知功能障碍、抑制炎症反应、保护海马组织神经元,激活ERK1/2/CREB/BDNF信号通路可能是其作用机制之一。