Dexamethasone suppresses DU145 cell proliferation and cell cycle through inhibition of the extracellular signal-regulated kinase 1 /2 pathway and cyclin D1 expression

Aim： To determine the mechanisms of glucocorticoids in inhibiting advanced prostate cancer growth. Methods： The cell proliferation and cell cycle of prostate cancer DU145 cells following dexamethasone treatment were determined by proliferation assay and fluorescence-activated cell sorter. Western blot analysis was carried out to evaluate the effects of dexamethasone on phosphorylation of extracellular signal-regulated kinase （ERK）1/2 and expression of cyclin D1 in DU145 cells with or without glucocorticoid receptor （GR） antagonist RU486. Reverse transcription- polymerase chain reaction verified the expression of GR mRNA in DU145 cells. Results： Dexamethasone significantly inhibited DU 145 cell proliferation at the G0/G1 phase. Westem blot analysis showed a dramatic reduction of ERK1/2 activity and cyclin D1 expression in dexamethasone-treated cells. The decreased phosphorylation of ERK1/2 in dexamethasone-treated cells was attenuated by GR blockade. Additionally, the effects of dexamethasone in inhibiting cyclin D1 expression were altered by GR blockade. Conclusion： Dexamethasone suppresses DU145 cell proliferation and cell cycle, and the underlying mechanisms are through the inhibition of phosphorylation of ERK1/2 and cyclin D1 expression. The inhibition of ERK1/2 phosphorylation and cyclin D1 expression is attenuated by GR blockade, suggesting that GR regulates ERK1/2 and cyclin D1 pathways. These observations suggest that dexamethasone has a potential clinical application in prostate cancer therapy.

Involvement of ERK1/2 and p38 MAPK in up-regulation of 14-3-3 protein induced by hydrogen peroxide preconditioning in PC12 cells

Objective To investigate the protective effects of hydrogen peroxide preconditioning （HPP） on the pheochromocytoma （PC12） cells treated with 1-methyl-4-phenylpyridinium （MPP^＋） and to explore the potential mechanisms. Methods The viability and apoptosis of PC 12 cells were determinded by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay and 4′,6′-diamidino-2-phenylindole （DAPI） staining, respectively. The expressions of 14-3-3 protein and phospholylated p38 mitogen-activated protein kinase （MAPK） were determined by Western blot. Enzyme-linked immunosorbent assay （ELISA） was used to measure the activity of extracellular signal-regulated protein kinase 1/2 （ERK1/2）. Results The cell viability decreased and the number of apoptotic cells increased dramatically in MPP^＋ group compared with that in Control group. HPP induced a significant increase in cell viability and a marked decrease in population of apoptotic cells of the MPP^＋- treated PC 12 cells, accompanied with up-regulation of 14-3-3 protein and increase of ERK 1/2 and p38 MAPK activities. The 14-3-3 protein expression was positively correlated with the phosphorylation of ERK1/2. Furthermore, inhibition of the ERK1/2 with PD98059 abolished the 14-3-3 protein up-regulation in PC 12 cells induced by HPP. Conclusion HPP protects PC 12 cells against MPP＋ toxicity by up-regulating 14-3-3 protein expression through the ERK1/2 and p38 MAPK signaling pathways.

Activation of extracellular signal-related kinases 1 and 2 in Sertoli cells in experimentally cryptorchid rhesus monkeys

Aim： To assess the spatiotemporal changes in the expression of extracellular signal-regulated kinases 1 and 2 （ERK1/ 2）, c-Jun N-terminal kinases （JNK） and p38 mitogen-activated protein kinases （MAPK） in response to heat stress in the cryptorchid testis, and to investigate a possible relation to Sertoli cell dedifferentiation. Methods： Immunohistochemistry and western blot were used to examine the expression and activation of ERK1/2, p38 and JNK in the cryptorchid testis at various stages after experimental cryptorchidism. Results： The abdominal temperature did not obviously change the total ERK1/2 expression but significantly activated phospho-ERK1/2 in the Sertoli cells of the cryptorchid testis. Heat stress increased total JNK expression in the Sertoli cells of the cryptorchid testis but did not activate phospho-JNK. Neither total p38 nor phospho-p38 was induced by heat stress in the Sertoli cells of the cryptorchid testis. Changes in the spatiotemporal expression of cytokeratin 18 （CK18）, a marker of immature or undifferentiated Sertoli cells, were induced in the cryptorchid testis in a pattern similar to the activation of ERK1/2. Condusion： The activation of ERK1/2 in the testis may be related to dedifferentiation of Sertoli cells under heat stress induced by experimental cryptorchidism.

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.

IL-1β通过激活ERK1/2信号通路抑制人脐带间充质干细胞CD200表达抑制巨噬细胞M2极化

目的探究白细胞介素1β(IL-1β)调控人脐带间充质干细胞CD200表达及其对巨噬细胞极化的影响及作用机制。方法无血清培养基分离培养获得人脐带间充质干细胞(hUC-MSC),形态学观察及流式细胞术检测CD73、CD90、CD105、CD14、CD34、CD45、人类白细胞抗原DR(HLA-DR)的表达,确定间充质干细胞属性;20 ng/mL IL-1β处理hUC-MSC 24 h,流式细胞术检测CD200阳性细胞率,实时定量PCR和Western blot法检测CD200 mRNA和蛋白表达水平;佛波酯(PMA)诱导THP-1巨噬细胞活化,并与IL-1β处理感染CD200过表达慢病毒的hUC-MSC共培养,流式细胞术检测CD11c和CD206阳性细胞比例;IL-1β联合细胞外信号调节激酶1/2(ERK1/2)特异性抑制剂PD98059处理hUC-MSC,Western blot法检测细胞丝裂原激活蛋白激酶(MAPK)信号分子与CD200的表达。结果IL-1β显著下调hUC-MSC CD200蛋白表达与CD200阳性细胞率;过表达CD200显著上调hUC-MSC CD200表达,且CD200过表达hUC-MSC提高巨噬细胞CD206阳性细胞比率;IL-1β激活hUC-MSC的ERK1/2信号通路,PD98059上调IL-1β处理后hUC-MSC中CD200的蛋白表达。结论IL-1β通过激活ERK1/2信号通路抑制CD200的表达,进而抑制hUC-MSC对巨噬细胞向M2型极化的促进作用。

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。

Activation of extracellular signal-related kinases 1 and 2 in Sertoli cells in experimentally cryptorchid rhesus monkeys

Aim:To assess the spatiotemporal changes in the expression of extracellular signal-regulated kinases 1 and 2(ERK1/ 2),c-Jun N-terminal kinases(JNK)and p38 mitogen-activated protein kinases(MAPK)in response to heat stress in the cryptorchid testis,and to investigate a possible relation to Sertoli cell dedifferentiation.Methods:Immunohis- tochemistry and western blot were used to examine the expression and activation of ERK1/2,p38 and JNK in the cryptorchid testis at various stages after experimental cryptorchidism.Results:The abdominal temperature did not obviously change the total ERK1/2 expression but significantly activated phospho-ERK1/2 in the Sertoli cells of the cryptorchid testis.Heat stress increased total JNK expression in the Sertoli cells of the cryptorchid testis but did not activate phospho-JNK.Neither total p38 nor phospho-p38 was induced by heat stress in the Sertoli cells of the cryptorchid testis.Changes in the spatiotemporal expression of cytokeratin 18(CK18),a marker of immature or undifferentiated Sertoli cells,were induced in the cryptorchid testis in a pattern similar to the activation of ERK1/2. Conclusion:The activation of ERK1/2 in the testis may be related to dedifferentiation of Sertoli cells under heat stress induced by experimental cryptorchidism.

补骨脂酚通过抑制ERK1/2磷酸化并上调ABCA1表达减少巨噬细胞源性泡沫细胞形成

[目的]探讨补骨脂酚(BAK)对巨噬细胞源性泡沫细胞脂质蓄积的影响及机制。[方法]MTT筛选BAK对泡沫细胞药物毒性浓度;油红O染色、NBD胆固醇、Dil-ox-LDL检测泡沫细胞内脂质蓄积情况;使用RT-qPCR和Western blot检测mRNA和蛋白表达。[结果]BAK可以促进胆固醇流出并减少泡沫细胞内脂质蓄积。BAK可以上调三磷酸腺苷结合盒转运体A1(ABCA1)的mRNA和蛋白表达水平,同时可下调细胞外信号调节激酶1/2(ERK1/2)磷酸化水平。使用ERK1/2激动剂Ro 67-7476处理发现,与BAK处理组相比,加入Ro 67-7476处理后ABCA1蛋白表达下降。[结论]BAK通过抑制ERK1/2的磷酸化,上调ABCA1的表达并促进胆固醇的流出,减少泡沫细胞中的脂质蓄积,从而抑制泡沫细胞的形成。

Regulating effect of glycyrrhetinic acid on bronchial asthma smooth muscle proliferation and apoptosis as well as inflammatory factor expression through ERK1/2 signaling pathway

Objective: To study the influence of glycyrrhetinic acid(GA) on bronchial asthma(BA)smooth muscle proliferation and apoptosis as well as inflammatory factor expression and its molecular mechanism.Methods: Male SD guinea pigs were selected and made into asthma models, bronchial asthma smooth muscle cells were cultured and divided into BA group, GA group and GA + LM group that were treated with serum-free RPMI1640 culture medium, serumfree RPMI1640 culture medium containing 50 ng/mL glycyrrhetinic acid, serum-free RPMI1640 culture medium containing 50 ng/mL glycyrrhetinic acid and 100 ng/mL LM22B-10 respectively; normal guinea pigs were collected and bronchial smooth muscle cells were cultured as control group. The cell proliferation activity as well as the expression of proliferation and apoptosis genes, inflammatory factors and p-ERK1/2 was determined.Results: Proliferation activity value and m RNA expression of Bcl-2, TNF-α, IL-4, IL-6,YKL-40, protein expression of p-ERK1/2 of airway smooth muscle cell in BA group were significantly higher than those of control group while m RNA expression levels of Bax,caspase-9 as well as caspase-3 were significantly lower than that of control group(P < 0.05); proliferation activity value and m RNA expression of Bcl-2, TNF-α, IL-4, IL-6, YKL-40, protein expression of p-ERK1/2 of airway smooth muscle cell in GA group were significantly lower than those of BA group(P < 0.05) while the m RNA expression levels of Bax, caspase-9 as well as caspase-3 were significantly higher than those of BA group(P < 0.05); proliferation activity value and m RNA expression of Bcl-2, TNF-α, IL-4, IL-6, YKL-40 of airway smooth muscle cell in GA + LM group were significantly higher than those of GA group(P < 0.05) while m RNA expression levels of Bax, caspase-9 as well as caspase-3 were significantly lower that of GA group(P < 0.05).Conclusion: GA can inhibit the proliferation of bronchial smooth muscle cells and reduce the expression of inflammatory factors by inhibiting the phosphorylation of ERK1/2.

Sphingosine-1-Phosphate Protects Against the Development of Cardiac Remodeling via Sphingosine Kinase 2 and the S1PR2/ERK Pathway

Objective:Cardiac remodeling is a common pathological change in various cardiovascular diseases and can ultimately result in heart failure.Thus,there is an urgent need for more effective strategies to aid in cardiac protection.Our previous work found that sphingosine-1-phosphate(S1P)could ameliorate cardiac hypertrophy.In this study,we aimed to investigate whether S1P could prevent cardiac fibrosis and the associated mechanisms in cardiac remodeling.Methods:Eight-week-old male C57BL/6 mice were randomly divided into a sham,transverse aortic constriction(TAC)or a TAC+S1P treatment group.Results:We found that S1P treatment improved cardiac function in TAC mice and that the cardiac fibrosis ratio in the TAC+S1P group was significantly lower and was accompanied by a decrease inα-smooth muscle actin(α-SMA)and collagen type I(COL I)expression compared with the TAC group.We also found that one of the key S1P enzymes,sphingosine kinase 2(SphK2),which was mainly distributed in cytoblasts,was downregulated in the cardiac remodeling case and recovered after S1P treatment in vivo and in vitro.In addition,our in vitro results showed that S1P treatment activated extracellular regulated protein kinases(ERK)phosphorylation mainly through the S1P receptor 2(S1PR2)and spurred p-ERK transposition from the cytoplasm to cytoblast in H9c2 cells exposed to phenylephrine.Conclusion:These findings suggest that SphK2 and the S1PR2/ERK pathway may participate in the anti-remodeling effect of S1P on the heart.This work therefore uncovers a novel potential therapy for the prevention of cardiac remodeling.

Human ciliary muscle cell responses to kinins:Activation of ERK1/2 and pro-matrix metalloproteinases secretion

AIM To study activation of extracellular signal-regulated kinase-1/2(ERK1/2) and pro-matrix metalloproteinases(pro-MMPs) secretion from isolated primary human ciliary muscle(h-CM) cells in response to bradykinin(BK) and other agonists. METHODS Serum-starved h-CM cells were challenged with vehicle, BK agonists or antagonists. Cell lysates were evaluated for phosphorylated ERK1/2 using homogeneous timeresolved fluorescence technology based on a sandwich immunoassay. Rabbit polyclonal anti-pro-MMP antibodies were used to measure pro-MMPs using immunoblot analysis.RESULTS A 10 min incubation time using 5 × 104 h-CM cells/well was optimum condition for studying stimulation of ERK1/2 phosphorylation. BK(100 nmol/L) caused a 1.86 ± 0.26 fold(n = 3) increase in ERK1/2 phosphorylation above baseline. BK analogs, Met-Lys-BK and RMP-7(100 nmol/L), also stimulated ERK1/2 phosphorylation by 1.57 ± 0.04 and 1.55 ± 0.09 fold, respectively. However, DesArg9-Bradykinin, a B1 receptor-selective agonist(0.1-1 μmol/L), was essentially inactive. HOE-140 or WIN-64338(B2-antagonists) appreciably blocked phosphorylation of ERK1/2 induced by various BK agonists. Pre-treatmentof cells with a prostaglandin(PG) synthase inhibitor(bromfenac; 1 μmol/L) failed to alter kinin-induced ERK1/2 activation. BK and a non-peptide BK agonist(FR-190997)(10 nmol/L-1 μmol/L) also enhanced pro-MMPs secretion(pro-MMP-1 > pro-MMP-3 > pro-MMP-2; 1.45-1.75-fold over baseline) from h-CM cells. CONCLUSION These collective data suggest that B2 kinin receptors initiate signaling in h-CM cells by a relatively rapid mechanism(within minutes) involving ERK1/2 activation which in turn regulates MMPs production(within hours). The latter process does not involve PGs.

ERK信号转导通路在CXCL12促进子宫内膜癌细胞增殖和侵袭中的作用

目的:探讨趋化因子CXCL12及其受体CXCR4(CXCL12/CXCR4)生物学轴通过细胞外信号调节激酶(extracellular signal-regulated kinase,ERK)信号转导通路发挥促子宫内膜癌细胞增殖和侵袭的作用。方法:应用外源性CXCL12处理子宫内膜癌Ishikawa细胞株,通过Western blotting检测不同时间位点ERK1/2的磷酸化水平和Survivin蛋白的表达;通过ELISA检测细胞培养上清液中MMP-2的分泌水平。同时分析AMD3100和PD98059对细胞ERK1/2磷酸化水平、Survivin蛋白水平和MMP-2分泌水平的影响。结果:外源性CXCL12刺激后,可迅速上调ERK1/2的磷酸化水平(t=0.887,P<0.01),促进Survivin蛋白和MMP-2蛋白的表达(t=0.861,P<0.01;t=0.297,P<0.01),且三者均呈时间依赖性。PD98059和AMD3100均能明显抑制外源性CXCL12诱导后ERK1/2的磷酸化水平,而且在两者共同作用下,能完全抑制ERK1/2的磷酸化水平,阻断ERK通路的激活,下调Survivin蛋白和MMP-2蛋白的表达。结论:CXCL12/CXCR4生物学轴通过激活ERK通路上调Survivin蛋白和MMP-2蛋白表达,从而引发Ishikawa细胞一系列增殖和侵袭的生物学效应。

子宫内膜癌中ERK1/2信号转导通路与雌、孕激素受体的相关性

目的检测丝裂原活化蛋白激酶(MAPK)信号通路中细胞外信号调控激酶1/2(ERK1/2)在子宫内膜癌中的表达,探讨其与雌激素受体(ER)和孕激素受体(PR)表达间的相关性。方法用免疫组化方法(SP法)检测30例子宫内膜癌石蜡标本中ERK1/2以及ER和PR的表达;同法检测20例正常子宫内膜、13例增生过长子宫内膜石蜡标本中ERK1/2的表达;对标本的染色情况做半定量分析。结果ERK1/2在正常子宫内膜、增生过长子宫内膜和子宫内膜癌中的表达水平比较,差异无统计学意义(P>0.05)。磷酸化的ERK1/2(p-ERK1/2)在ER阳性与ER阴性子宫内膜癌中的高表达率比较(76.5%vs30.8%),差异有统计学意义(P<0.05);且p-ERK1/2的高表达率与ER的表达水平呈正相关(r=0.457,P<0.05);p-ERK1/2的高表达率与PR的表达水平无相关性(P>0.05)。结论ERK1/2信号转导通路与子宫内膜恶变过程无相关性,其活化与ER表达水平呈正相关。ER可能通过ERK1/2信号通路发挥其在子宫内膜癌中的调控作用。

人参皂苷Rg1对局灶性脑缺血再灌注损伤大鼠海马p-ERK1/2与p-JNK表达的影响

目的探讨人参皂苷Rg1抗脑缺血再灌注(ischemia reperfusion,I/R)损伤大鼠海马神经元凋亡的可能机制。方法成年健康雌性SD大鼠120只随机分为脑缺血再灌注模型组(模型组)、人参皂苷Rg1低(10mg/kg)、中(20mg/kg)、高剂量(40mg/kg)组及假手术组,每组18只。各组均腹腔注射给药,假手术组及模型组腹腔注射等量生理盐水,每天1次,连续7天,末次给药后30min,大鼠右侧大脑中动脉阻塞(middle cerebral artery occlusion,MCAO)2h再灌注24h制备I/R模型。以LongaEZ法评定神经功能,尼氏染色、TUNEL染色观察海马锥体神经细胞的损伤情况,并计算神经细胞凋亡率。采用Westernblot法检测细胞外信号调节蛋白激酶1/2(extracellular signal-regulated kinase1/2,ERK1/2)及磷酸化细胞外信号调节蛋白激酶1/2(phosphorylated extracellular signal-regulated kinase1/2,p-ERK1/2)、c-Jun氨基末端激酶(c-Jun N-terminal kinases,JNK)及磷酸化c-Jun氨基末端激酶(phosphorylated c-Jun N-terminal kinases,p-JNK)表达。结果与假手术组比较,模型组神经功能评分、细胞凋亡率、p-JNK、p-ERK1/2蛋白表达升高(P<0.05,P<0.01),锥体细胞存活数减少(P<0.01);与模型组比较,人参皂苷Rg1各剂量组神经功能评分、细胞凋亡率降低(P<0.05,P<0.01),人参皂苷Rg1中、高剂量组大鼠锥体细胞存活数增加,海马CA1区p-JNK蛋白表达降低,p-ERK1/2表达升高(P<0.05,P<0.01)。假手术组海马CA1区有3-4层锥体细胞,排列整齐、紧密,高倍镜下细胞核大而圆,有1～2个核仁。脑组织缺血损伤后,海马区神经细胞受损严重,CA1区失去正常结构,细胞排列散乱,细胞数量减少。部分神经元皱缩,核固缩、深染,呈三角形、长条形、梭形或不规则形,核染色聚集,核仁不清晰。与人参皂苷Rg1低剂量组比较,人参皂苷Rg1中、高剂量组神经功能评分、细胞凋亡率及p-JNK蛋白表达降低(P<0.05,P<0.01),锥体细胞存活数增加,p-ERK1/2表达升高(P<0.05,P<0.01)。人参皂苷Rg1中、高剂量能够改善缺血神经细胞形态,减少神经细胞的丢失,其中,高剂量组作用强于低剂量组。JNK蛋白条带分为两个亚带,JNK1是分子量为46kD的蛋白,JNK2分子量为54kD。ERK蛋白条带也分为两个亚带,ERK1是分子量为44kD的蛋白,ERK2分子量为42kD的蛋白。结论人参皂苷Rg1对I/R大鼠的保护作用与抑制海马神经元凋亡,调节p-JNK及p-ERK1/2表达水平有关。

血管紧张素-(1-7)对大鼠血管平滑肌细胞PKC和ERK1/2的抑制作用

采用Westernblot、氚 胸腺嘧啶 ( 3H TdR)和氚 亮氨酸 ( 3H Leu )掺入等技术和方法 ,用血管紧张素Ⅱ(AngⅡ )和血管紧张素 ( 1 7) [Ang ( 1 7) ]刺激大鼠血管平滑肌细胞 (VSMCs) ,观察和分析Ang ( 1 7)对VSMCs增殖及蛋白激酶C (PKC)和胞外调节蛋白激酶 (ERK)表达的影响。Ang ( 1 7)能明显抑制基础和AngⅡ刺激下的VSMCsPKC ζ和ERK1/ 2蛋白表达 (P <0 0 1或P <0 0 5 ) ,减少3H TdR和3H Leu掺入量 (P <0 0 1或P <0 0 5 )。结果提示 ,Ang ( 1 7)对VSMCs增殖有抑制作用 ,这可能与影响PKC ζ和ERK1/ 2蛋白表达有关。

氢溴酸樟柳碱对急性脑缺血再灌注损伤模型大鼠脑组织细胞凋亡及ERK1/2磷酸化水平的影响

目的:研究氢溴酸樟柳碱对急性脑缺血再灌注损伤模型大鼠脑组织细胞凋亡及细胞外信号调节蛋白激酶1/2(ERK1/2)磷酸化(p-ERK1/2)水平的影响。方法:将大鼠随机分为假手术组、模型组、阳性对照组(尼莫地平1.0 mg/kg)和氢溴酸樟柳碱高、中、低、极低剂量组(1.2、0.6、0.3、0.15 mg/kg),每组8只,采用线栓法建立大鼠急性脑缺血再灌注损伤模型。分别于脑缺血2 h和再灌注6 h时对各组大鼠尾iv给药1次,再灌注22 h后检测各组大鼠脑组织三磷酸腺苷(ATP)酶活性、Ca^(2+)含量、细胞凋亡情况、脑组织中p-ERK1/2蛋白表达和p-ERK1/2/总ERK1/2(t-ERK1/2)比例。结果:与假手术组比较,模型组大鼠脑组织ATP酶活性明显降低、Ca^(2+)含量明显增加、凋亡细胞密度明显增加,以上差异均有统计学意义(P<0.01)。与模型组比较,各给药组大鼠脑组织凋亡细胞密度均明显减小,阳性对照组和氢溴酸樟柳碱高、低剂量组大鼠脑组织Ca^(2+)含量均明显降低,氢溴酸樟柳碱高、低、极低剂量组大鼠脑组织中p-ERK1/2/t-ERK1/2比例均明显增加,以上差异均有统计学意义(P<0.05或P<0.01);其余差异均无统计学意义(P>0.05)。结论:氢溴酸樟柳碱能抑制急性脑缺血再灌注损伤模型大鼠脑组织细胞凋亡,其作用机制可能与激活ERK1/2信号通路和调节ATP酶活性,进而降低脑组织Ca^(2+)含量有关。

IL-33通过ERK1/2信号通路促进哮喘模型小鼠气道重塑

目的探讨白细胞介素(IL-33)诱导支气管哮喘气道重塑的机制。方法雄性BALB/c小鼠随机分为对照组、卵清蛋白(OVA)组和IL-33中和抗体联合OVA组。HE染色观察小鼠气道重塑,免疫组织化学染色及Western blot法观察IL-33、α平滑肌肌动蛋白(α-SMA)、1型胶原蛋白(Col1)的表达,Western blot法检测细胞外信号调节激酶1/2(ERK1/2)及丝裂原和应激激活的蛋白激酶1(MSK1)的磷酸化水平;培养HLF-1人成纤维细胞,分别给予人重组IL-33(r IL-33)、ERK1/2的抑制剂U0126联合r IL-33、MSK1的抑制剂H89联合r IL-33处理;实时荧光定量PCR及Western blot法检测α-SMA与Col1的mRNA和蛋白表达水平,免疫荧光细胞化学技术观察ERK1/2及MSK1的磷酸化。结果 OVA组小鼠发生气道重塑,IL-33、α-SMA、Col1表达增加,ERK1/2及MSK1磷酸化增强;IL-33中和抗体预处理可显著降低OVA诱导的小鼠气道重塑及IL-33、α-SMA、Col1表达以及ERK1/2及MSK1的磷酸化。U0126或H89可抑制r IL-33引起的HLF-1细胞中ERK1/2及MSK1磷酸化增强及α-SMA与Col1表达增加。结论 IL-33通过ERK1/2-MSK1信号通路促进哮喘模型小鼠气道重塑。

17β-雌二醇对子宫内膜异位症患者在位子宫内膜间质细胞ERK1/2信号转导通路活化的影响

目的研究17β-雌二醇（17β-E2）对子宫内膜异位症（内异症）患者在位子宫内膜间质细胞胞外信号调节激酶1/2（ERK1/2）信号转导通路活化的影响,探讨ERK1/2信号转导通路在介导雌激素促进内异症发生发展中的作用。方法体外分离培养内异症患者在位子宫内膜间质细胞。用1×10^-6mol/L 17β-E2处理子宫内膜间质细胞不同时间（0~120 min）,然后用MTT法和免疫印迹法（Western blot）检测子宫内膜间质细胞的活性和ERK1/2的活化情况,检测出子宫内膜间质细胞活性最强的时间点。用Western blot和MTT法分别检测不同浓度ERK1/2抑制剂PD98059对1×10^-6mol/L 17β-E2作用20 min后子宫内膜间质细胞活性及ERK1/2活性的变化。结果 1×10^-6mol/L的17β-E2作用20 min时,子宫内膜间质细胞的活性最强,ERK1/2活化在17-βE2作用10 min后出现,在20 min时达高峰;随着PD98059作用浓度的增加,ERK1/2活化水平逐渐下降,浓度为50μmol/L时已被完全阻断;随着PD98059作用浓度的增加,子宫内膜间质细胞活性逐渐下降,在50μmol/L和100μmol/L时,活性最低,但此时仍高于空白对照组。结论 17β-E2增强子宫内膜间质细胞的活性可能与17β-E2通过非转录机制,迅速激活子宫内膜间质细胞的ERK1/2信号转导通路有关。

TROP2、p-ERK1/2和Cyclin D1在胆囊癌组织中的表达及临床意义

目的探讨胆囊癌组织中人滋养层细胞表面抗原(TROP)2、磷酸化细胞外信号调节激酶(p-ERK)1/2和细胞周期蛋白D1(Cyclin D1)的表达及其与临床病理参数之间的关系,并分析其与胆囊癌患者预后的关系。方法搜集第二军医大学附属长征医院2005年6月-2010年6月确诊并获取病理标本的胆囊癌患者88例,采用免疫组化法检测88例胆囊癌组织及15例癌旁组织中TROP2、p-ERK1/2和Cyclin D1蛋白的表达。计数资料采用χ~2检验,Spearman检验法分析TROP2、p-ERK1/2和Cyclin D1间相关性;单因素和多因素Cox回归分析胆囊癌患者预后的影响因素;Kaplan-Meier法绘制患者的生存曲线。结果 TROP2、p-ERK1/2和Cyclin D1蛋白在胆囊癌组织中的阳性表达率分别为74.30%、58.40%和55.30%,明显高于癌旁组织中的表达(5.42%、35.67%和39.87%)(P值均<0.05)。TROP2、p-ERK1/2和Cyclin D1蛋白的表达与胆囊结石、肿瘤直径、分化程度、血管神经侵犯、淋巴结转移、手术方式及TNM分期相关(χ~2=4.300~53.315,P值均<0.05)。TROP2与p-ERK1/2、Cyclin D1的表达呈正相关(rs值分别为0.402、0.742,P值均<0.001),且p-ERK1/2与Cyclin D1的表达也呈正相关(rs=0.242,P=0.023)。多因素生存分析提示,TROP2的阳性表达是患者3年生存率的独立危险因素(相对危险度=2.412,95%可信区间:1.186~5.126,P=0.010)。结论 TROP2的高表达可能是胆囊癌恶性进展的重要原因,高表达的TROP2可能介导p-ERK1/2和Cyclin D1的高表达,导致胆囊癌恶性进展。TROP2是判断胆囊癌患者预后的独立危险因素,有可能是临床干预的有效靶点。

黄连素抑制ERK1/2途径减轻大气细颗粒物对EA.hy926内皮细胞损伤的研究

目的:探讨大气细颗粒物(PM2.5)对EA.hy926型人脐静脉内皮细胞的损伤及黄连素的保护作用及其机制。方法:采集大气PM2.5并分别以0、20、200、400 mg/L染毒EA.hy926细胞24 h,MTT法检测细胞存活率、流式细胞术检测细胞凋亡、Western blot法检测p-ERK1/2、BAX、BCL-2蛋白表达,ELISA法测IL-6、TNF-α、MDA含量及SOD、LDH活性;分别加入黄连素(10、50、100μmol/L)和ERK1/2通路特异性阻滞剂PD98059 20μmol/L检测黄连素的干预作用。结果:与对照组比较,PM2.5染毒后呈剂量依赖性降低细胞存活率,并上调p-ERK1/2蛋白水平及BAX/BCL-2蛋白比率以促进细胞凋亡、诱导分泌IL-6、TNF-α及升高MDA含量、降低SOD活性、升高LDH活性(P<0.05);黄连素呈剂量依赖性升高PM2.5作用下细胞存活率、下调p-ERK1/2蛋白水平及BAX/BCL-2蛋白比率以抑制细胞凋亡、降低IL-6、TNF-α及MDA含量、升高SOD活性、降低LDH活性(P<0.05)。结论:黄连素能通过抑制ERK1/2通路,减轻PM2.5对EA.hy926细胞的损伤。