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.

Time-dependent effects of electroacupuncture at the Ren channel on extracellular signal-regulated kinases 1/2 expression in focal cerebral ischemia rats

BACKGROUND： The onset of focal cerebral ischemia activates extracellular signal-regulated kinases 1 and 2, regulates cell cycle, promotes cell proliferation and differentiation, and affects the normal stage and function of brain cells. OBJECTIVE： To observe the effects of electroacupuncture at the Ren channel on extracellular signal-regulated kinases 1/2 expression in the lateral cerebral ventricle wall of rats with focal cerebral ischemia. The effects were analyzed at different time points after intervention. DESIGN： Randomized controlled study. SETTING： Department of Anatomy, Sun Yat-Sen University. MATERIALS： A total of 60 healthy adult male Wistar rats weighing （250±10） g were provided by the Experimental Animal Center, Medical College of Sun Yat-Sen University. The animal experiment was conducted with confirmed consent by the local ethics committee. The GB6805-Ⅱ electric acupuncture apparatus was provided by Shanghai Medical Equipment High-techno Company. METHODS： The experiment was performed at the Laboratory of Anatomy, Sun Yat-Sen University, from February to July 2007. All experimental animals were randomly divided into the following groups： normal group （n = 6）, sham operation group （n = 18）, model group （n = 18）, and electroacupuncture group （n = 18）. Middle cerebral artery occlusion （MCAO） was performed in the model group and electroacupuncture group. Zea Longa＇s grading standard was used to assess neurological impairment after reperfusion; animals whose grades were between l and 4 were included in this study. The normal control group was not exposed to MCAO. In sham operation animals, the right common carotid artery （CCA） was isolated, and the external carotid artery （ECA） was damaged, but no embolism was induced. The electroacupuncture group was given acupuncture on the second day after surgery. The acupoint locations were chosen according to Experimental Acupuncture （People＇s Publishing House; 1997; First Edition）. The Chengjiang, Qihai, and Guanyuan acupoints were labeled and connected to a G6805 electroacupuncture apparatus with sparse-dense waves （sparse waves were 30 Hz, dense waves were 100 Hz）, with a frequency of 6-15 V. The duration was 20 minutes. Two days after surgery, the model and sham operation groups were placed with their backs on the operating table, but they received no acupuncture. However, the normal group received acupuncture. The experimental animals under anesthesia were sacrificed on days 7, 14, and 28 post-surgery. Western blot analysis was used to measure expression of extracellular signal-regulated kinases 1/2 in the inferior region of the lateral cerebral ventricle wall. Expression was measured in the normal group at time points corresponding to the sham operation group. MAIN OUTCOME MEASURES： Expression of extracellular signal-regulated kinases 1/2 in the inferior region of the lateral cerebral ventricle wall at different time points after intervention. RESULTS： All 60 rats were included in the final analysis, without any loss. Seven days after MCAO, there was no significant difference in extracellular signal-regulated kinases 1/2 expression in the electroacupuncture group compared to the model group （P 〉 0.05）. However, extracellular signal-regulated kinases 1/2 expression significantly increased in the model group at 14 and 28 days after treatment （P 〈 0.05）. CONCLUSION： Electroacupuncture at the Ren channel can enhance extracellular signal-regulated kinasesl/2 expression in the inferior region of the lateral cerebral ventricle wall of rats with focal cerebral ischemia. However, this effect is not apparent until 14 days after electroacupuncture intervention.

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。

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.

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.

microRNA125a-3p对滋养层细胞功能的调控作用及机制

目的观察microRNA125a-3p(miR-125a-3p)在滋养层细胞中的表达,探讨其对滋养层细胞增殖、侵袭和凋亡的调控及机制。方法荧光实时定量PCR检测人滋养层细胞系HTR-8/SVneo、绒癌细胞系JAR和JEG-3中miR-125a-3p的表达情况。以HTR-8/SVneo和JEG-3细胞为实验对象,分为3组:空白对照组(CK组),未做任何处理;阴性对照组(NC组),转染NC-inhibitor;实验组(inhibitor组),转染miR-125a-3p inhibitor。以Transwell、流式细胞仪、CCK8法分别检测细胞的侵袭、凋亡及增殖能力。Western blot检测Fyn蛋白表达情况及ERK1/2、STAT3磷酸化水平。荧光实时定量PCR检测Fyn mRNA水平,免疫共沉淀法检测Fyn活性水平。结果miR-125a-3p mRNA表达水平在HTR-8/SVneo、JAR和JEG-3细胞中依次降低,两两比较均有统计学差异(P<0.01)。抑制HTR-8/SVneo和JEG-3中miR-125a-3p后,细胞的凋亡水平明显降低,侵袭和增殖能力均明显升高(P<0.05);Fyn mRNA和蛋白的表达及活性水平均明显升高(P<0.05);ERK1/2及STAT3的磷酸化水平均不同程度增加(P<0.05)。结论本研究首次在滋养层细胞中检测到miR-125a-3p的表达。miR-125a-3p通过作用于Fyn和ERK1/2-STAT3信号通路可抑制滋养层细胞的增殖、侵袭,促进其凋亡。

MicroRNA-133b调节FGFR1-ERK1/2-SOX2信号通路对裸鼠肺癌NCI-H1975细胞移植瘤生长的影响

目的探讨microRNA-133b(miR-133b)对裸鼠肺癌NCI-H1975细胞移植瘤生长的抑制作用以及对成纤维细胞生长因子受体1-细胞外信号调节激酶1/2-性别决定区Y-box蛋白2信号通路(FGFR1-ERK1/2-SOX2)的影响。方法q RT-PCR检测人肺成纤维细胞、肺癌细胞株miR-133b表达。miR-133b过表达NCIH1975细胞。将NCI-H1975细胞分为对照组、mimic NC组、miR-133b mimic组、miR-133b mimic+pcDNA3.1组、miR-133b mimic+pcDNA3.1 FGFR1组。CCK-8法检测NCI-H1975细胞增殖抑制率,Transwell实验观察NCI-H1975细胞侵袭、迁移情况。复制裸鼠移植瘤模型并分组,将裸鼠分为对照组、mimic NC组、miR-133b mimic组、miR-133b mimic+AZD4547组,观察各组裸鼠肿瘤体积与重量,HE染色观察各组裸鼠肿瘤组织变化,TUNEL检测肿瘤组织细胞凋亡情况,免疫组织化学法观察裸鼠肿瘤组织Ki-67、Cyclin D1、VEGF-A的表达,Western blotting检测各组肿瘤组织FGFR1、p-ERK1/2/ERK1/2、SOX2蛋白相对表达量。结果与人肺成纤维细胞HLF-α比较,肺癌细胞株NCI-H1975、A427、NGE-1、A549中miR-133b mRNA相对表达量降低(P<0.05),其中以NCI-H1975细胞中miR-133b mRNA相对表达量最低。miR-133b mimic组miR-133b mRNA相对表达量较对照组和mimic NC组升高(P<0.05)。miR-133b可通过负调控FGFR1抑制肺癌NCIH1975细胞增殖和迁移。miR-133b mimic组移植瘤重量较对照组降低、体积缩小,miR-133b mimic+AZD4547组移植瘤重量较miR-133b mimic组降低、体积缩小(P<0.05)。miR-133b mimic组空泡样变性程度较对照组、mimic NC组减轻(P<0.05),miR-133b mimic+AZD4547组空泡样变性程度较miR-133b mimic组减轻(P<0.05)。miR-133b mimic组肿瘤组织细胞凋亡率较对照组升高(P<0.05),miR-133b mimic+AZD4547组肿瘤组织细胞凋亡率较miR-133b mimic组升高(P<0.05)。miR-133b mimic组VEGF-A、Cyclin D、Ki-67阳性细胞比例较对照组降低(P<0.05),miR-133b mimic+AZD4547组VEGF-A、Cyclin D、Ki-67阳性细胞比例较miR-133b mimic组降低(P<0.05)。miR-133b mimic组FGFR1、p-ERK1/2/ERK1/2、SOX2蛋白相对表达量较对照组降低(P<0.05),miR-133b mimic+AZD4547组FGFR1、p-ERK1/2/ERK1/2、SOX2蛋白相对表达量较miR-133b mimic组降低(P<0.05)。结论miR-133b过表达可能通过抑制FGFR1-ERK1/2-SOX2轴,抑制裸鼠肺癌NCI-H1975细胞移植瘤生长。

Emodin regulating excision repair cross-complementation group 1 through fibroblast growth factor receptor 2 signaling

AIM: To investigate the molecular mechanisms underlying the reversal effect of emodin on platinum resistance in hepatocellular carcinoma. METHODS: After the addition of 10 μmol/L emodin to HepG2/oxaliplatin (OXA) cells, the inhibition rate (IR), 50% inhibitory concentration (IC 50 ) and reversal index (IC 50 in experimental group/IC 50 in control group) were calculated. For HepG2, HepG2/OXA, HepG2/OXA/T, each cell line was divided into a control group, OXA group, OXA + fibroblast growth factor 7 (FGF7) group and OXA + emodin group, and the final concentrations of FGF7, emodin and OXA in each group were 5 ng/mL, 10 μg/mL and 10 μmol/L, respectively. Single-cell gel electrophoresis was conducted to detect DNA damage, and the fibroblast growth factor receptor 2 (FGFR2), phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2) and excision repair cross-complementing gene 1 (ERCC1) protein expression levels in each group were examined by Western blotting. RESULTS: Compared with the IC50 of 120.78 μmol/L in HepG2/OXA cells, the IC 50 decreased to 39.65 μmol/L after treatment with 10 μmol/L emodin; thus, the reversal index was 3.05. Compared with the control group, the tail length and Olive tail length in the OXA group, OXA + FGF7 group and OXA + emodin group were significantly increased, and the differences were statistically significant (P < 0.01). The tail length and Olive tail length were lower in the OXA + FGF7 group than in the OXA group, and this difference was also statistically significant. Compared with the OXA + FGF7 group, the tail extent, the Olive tail moment and the percentage of tail DNA were significantly increased in the OXA + emodin group, and these differences were statistically significant (P < 0.01). In comparison with its parental cell line HepG2, the HepG2/OXA cells demonstrated significantly increased FGFR2, p-ERK1/2 and ERCC1 expression levels, whereas the expression of all three molecules was significantly inhibited in HepG2/ OXA/T cells, in which FGFR2 was silenced by FGFR2 shRNA. In the examined HepG2 cells, the FGFR2, p-ERK1/2 and ERCC1 expression levels demonstrated increasing trends in the OXA group and OXA + FGF7 group. Compared with the OXA group and OXA + FGF7 group, the FGFR2, p-ERK1/2, and ERCC1 expression levels were significantly lower in the OXA + emodin group, and these differences were statistically significant. In the HepG2/OXA/T cell line that was transfected with FGFR2 shRNA, the FGFR2, p-ERK1/2 and ERCC1 expression levels were significantly inhibited, but there were no significant differences in these expression levels among the OXA, OXA + FGF7 and OXA + emodin groups. CONCLUSION: Emodin markedly reversed OXA resistance by enhancing OXA DNA damage in HepG2/OXA cells, and the molecular mechanism was related to the inhibitory effect on ERCC1 expression being mediated by the FGFR2/ERK1/2 signaling pathway.

miR-141-5p影响黏膜黑色素瘤细胞生物学行为的机制研究

目的探讨miR-141-5p在黏膜黑色素瘤(MM)组织及细胞中的表达及其意义,分析其影响MM细胞生物学行为的机制。方法回顾性收集2015年1月至2020年12月温州医科大学附属第一医院手术切除的MM和色素痣组织标本。qRT-PCR法检测并比较MM和色素痣组织、MM细胞株A375和人角质形成细胞株HaCaT中miR-141-5p、细胞外信号调节激酶(ERK)1/2 mRNA的相对表达量。采用Pearson相关分析miR-141-5p与ERK1/2 mRNA相对表达量的相关性。A375分别用miR-141-5p模拟物(模拟物组)、miR-141-5p模拟物对照(模拟物对照组)、miR-141-5p抑制物(抑制物组)和miR-141-5p抑制物对照(抑制物对照组)处理;采用qRT-PCR检测并比较4组细胞中miR-141-5p相对表达量;采用细胞计数(CCK)-8法、克隆形成实验、流式细胞术、划痕实验和Transwell侵袭实验观察并比较4组细胞存活率、增殖能力、细胞凋亡比例和细胞迁移、侵袭能力;采用Western blot法观察并比较4组细胞ERK1/2、磷酸化的ERK1/2(p-ERK1/2)蛋白相对表达量。采用HE染色、免疫组化染色观察MM和色素痣组织形态并检测p-ERK1/2、ERK1/2表达水平,比较不同p-ERK1/2、ERK1/2表达情况MM患者临床病理特征差异。结果miR-141-5p和ERK1/2 mRNA在MM组织和A375中表达下调(均P<0.01);Pearson相关分析显示,miR-141-5p与ERK1/2 mRNA相对表达量呈正相关(P<0.05)。相比对照组,模拟物组细胞增殖和迁移、侵袭能力显著降低,细胞凋亡比例升高,抑制物组细胞增殖和迁移、侵袭能力升高,细胞凋亡比例降低(均P<0.05)。相比对照组,模拟物组细胞p-ERK1/2蛋白相对表达量显著升高,抑制物组显著降低(均P<0.05)。MM组织中ERK1/2与p-ERK1/2蛋白表达明显减少(均P<0.05)。p-ERK1/2阴性组和阳性组、ERK1/2阴性组和阳性组不同临床病理特征比较,差异均无统计学意义(均P>0.05)。结论miR-141-5p可能通过ERK1/2通路影响MM细胞生物学行为。

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.

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.

6-OHDA Induces Cycle Reentry and Apoptosis of PC12 Cells through Activation of ERK1/2 Signaling Pathway

This study investigated the effect and mechanism of cell cycle reentry induced by 6-hydrodopamine （6-OHDA） in PC12 cells. By using neural differentiated PC12 cells treated with 6-OHDA, the apoptosis model of dopaminergic neurons was established. Cell viability was measured by MTT. Cell apoptosis and the distribution of cell cycle were assessed by flow cytometry. Western blot was used to detect the activation of extracellular regulator kinasel/2 （ERK1/2） pathway and the phosphorylation of retinoblastoma protein （RB）. Our results showed that after PC12 cells were treated wtih 6-OHDA, the viability of PC12 cells was declined in a concentration-dependent manner. Flow cytornetry revealed that 6-OHDA could increase the apoptosis ratio of PC12 cells in a time-dependent manner. The percentage of ceils in G0/G1 phase of cell cycle was decreased and that in S phase and G2/M phase increased. Simultaneously, ERK1/2 pathway was activated and phosphorylated RB increased. It was concluded that 6-OHDA could induce cell cycle reentry of dopaminergic neurons through the activation of ERK1/2 pathway and RB phosphorylation. The aberrant cell cycle reentry contributes to the apoptosis of dopaminergic neurons.

Cross-Talk between Extracellular S1P/S1P2 and P42/44 MAPK in bcr/abl Positive Chronic Myeloid Leukemia Cells

Objective： BCR/ABL oncoprotein-expression is associated with uncontrolled cell growth. Sphingosine kinase 1 （SPK1） regulates the production of sphingosine 1-phosphate （S1P）, a key lipid signal molecular in cell proliferation and survival. The objective of this study was to elucidate the roles of S1P and its receptors in bcr/abl positive chronic myeloid leukemia （CML） cells. Methods： The expressions of SIP receptors： S1P1, S1P2 and S1P3 in CML cells were detected by RT-PCR. SPK1 expression, activity and extracellular S1P were determined in ECV304 and HL-60 cells which were transfected with bcr/abl gene. To elucidate the relationship between the BCR/ABL, ERK/MAPK （extracellular signal-regulated kinase/mitogen-activated protein kinase）, SPK/S 1P and S 1P/S 1 P2 signal pathways, bcr/abl positive CML cell line K562 was treated with STI571, PD98059, N,N-dimethyl sphingosine （DMS） and JTE-013. Results： Retrovirus-mediated overexpression of bcr/abl gene in ECV304 and HL-60 cells resulted in upregulation of the expression, activity of SPK1 and increase of the secretion of SIP, whereas treatment of STI571 and PD98059 decreased the BCR/ABL-induced S1P secretion. Treatment of DMS reduced S1P secretion and P42/44MAPK phosphorylation. S1P2-selective antagonist JTE-013 could also decrease P42/44MAPK phosphorylation. Conclusion： These results suggest that BCR/ABL up-regulates extracellular sphingosine 1-phosphate through sphingosine kinase 1 and there is cross-talk between SPK1/S1P/S1P2 and P42/44MAPK in bcr/abl positive CML cells.

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。

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。

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。