Overexpression of mitogen-activated protein kinase phosphatase-1 in endothelial cells reduces blood-brain barrier injury in a mouse model of ischemic stroke

Ischemic stroke can cause blood-brain barrier(BBB)injury,which worsens brain damage induced by stroke.Abnormal expression of tight junction proteins in endothelial cells(ECs)can increase intracellular space and BBB leakage.Selective inhibition of mitogen-activated protein kinase,the negative regulatory substrate of mitogen-activated protein kinase phosphatase(MKP)-1,improves tight junction protein function in ECs,and genetic deletion of MKP-1 aggravates ischemic brain injury.However,whether the latter affects BBB integrity,and the cell type-specific mechanism underlying this process,remain unclear.In this study,we established an adult male mouse model of ischemic stroke by occluding the middle cerebral artery for 60 minutes and overexpressed MKP-1 in ECs on the injured side via lentiviral transfection before stroke.We found that overexpression of MKP-1 in ECs reduced infarct volume,reduced the level of inflammatory factors interleukin-1β,interleukin-6,and chemokine C-C motif ligand-2,inhibited vascular injury,and promoted the recovery of sensorimotor and memory/cognitive function.Overexpression of MKP-1 in ECs also inhibited the activation of cerebral ischemia-induced extracellular signal-regulated kinase(ERK)1/2 and the downregulation of occludin expression.Finally,to investigate the mechanism by which MKP-1 exerted these functions in ECs,we established an ischemic stroke model in vitro by depriving the primary endothelial cell of oxygen and glucose,and pharmacologically inhibited the activity of MKP-1 and ERK1/2.Our findings suggest that MKP-1 inhibition aggravates oxygen and glucose deprivation-induced cell death,cell monolayer leakage,and downregulation of occludin expression,and that inhibiting ERK1/2 can reverse these effects.In addition,co-inhibition of MKP-1 and ERK1/2 exhibited similar effects to inhibition of ERK1/2.These findings suggest that overexpression of MKP-1 in ECs can prevent ischemia-induced occludin downregulation and cell death via deactivating ERK1/2,thereby protecting the integrity of BBB,alleviating brain injury,and improving post-stroke prognosis.

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。

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.

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.

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。

miR-17-5p对缺血性脑卒中大鼠的神经保护作用及其对细胞外调节蛋白激酶1/2信号通路的影响

目的:观察miR-17-5p对缺血性脑卒中大鼠的神经保护作用及其对胞外调节蛋白激酶1/2(ERK1/2)信号通路的影响。方法:将大鼠随机数字法分为模型组、miR-17-5p mimics组、miR-17-5p inhibitor组。建模后,模型组经尾静脉注射10 mL/kg生理盐水,miR-17-5p mimics组、miR-17-5p inhibitor组分别经尾静脉注射7μL miR-17-5p mimics、miR-17-5p inhibitor与RNAi脂质体转染试剂的混合溶液。各组大鼠苏醒后的24 h进行神经功能评分,测定脑梗死体积、大鼠脑组织含水量,检测缺血侧大脑皮质细胞凋亡率,caspase-3、Bax、Bcl-2和ERK1/2蛋白表达。结果:miR-17-5p mimics组的神经功能障碍评分、脑梗死体积、脑组织含水量、缺血侧大脑皮质细胞凋亡率明显低于模型组,miR-17-5p inhibitor组的神经功能障碍评分、脑梗死体积、脑组织含水量、缺血侧大脑皮质细胞凋亡率显著高于其他2组;miR-17-5p mimics组大鼠缺血脑组织中caspase-3、Bax蛋白表达明显低于模型组,Bcl-2、p-ERK1/2蛋白表达高于模型组;miR-17-5p inhibitor组大鼠缺血脑组织中caspase-3、Bax、p-ERK1/2蛋白表达显著高于其他2组,Bcl-2蛋白表达低于其他2组。结论:miR-17-5p对缺血性脑卒中大鼠的脑损伤具有一定的保护作用,miR-17-5p可抑制ERK1/2信号通路激活。

莓茶提取物对2型糖尿病大鼠糖脂代谢及肝脏SIRT1、AMPK、PGC-1α蛋白表达的影响

目的探索莓茶提取物对2型糖尿病(type 2 diabetes mellitus,T2DM)大鼠糖脂代谢及肝脏沉默信息调节因子1(silence information regulator 1,SIRT1)、AMP活化蛋白激酶(AMP activated protein kinase,AMPK)、过氧化物酶体增殖物激活受体γ辅助活化因子1α(peroxisome proliferator-activated receptor-γcoactivator-1α,PGC-1α)蛋白表达的影响。方法高脂高糖喂养联合链脲佐菌素(35 mg/kg)腹腔注射建立T2DM大鼠模型,建模成功后随机分为模型组、莓茶低剂量组(0.4 g/kg)、莓茶高剂量组(0.8 g/kg),另设普通饲料喂养大鼠为正常组,每组8只。各组灌胃给药6周后,行口服葡萄糖耐量试验计算血糖-时间曲线下面积(area under the curve,AUC),ELISA法检测空腹血胰岛素(fasting insulin,FINS)水平,计算稳态模型以评估胰岛素抵抗指数(homeostatic model assessment for insulin resistance,HOMA-IR),全自动生化分析仪测定血清总胆固醇(total cholesterol,TC)、甘油三酯(triglycerides,TG)、高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)、低密度脂蛋白胆固醇(low density lipoprotein cholesterol,LDL-C)、超氧化物歧化酶(superoxide dismutase,SOD)、丙二醇(malondialdehyde,MDA)水平,HE染色观察肝脏组织形态学变化,Western blot检测肝脏SIRT1、AMPK、PGC-1α蛋白表达。结果与正常组比较,模型组FBG、AUC、FINS、HOMA-IR、TC、TG、LDL-C、MDA均明显升高(P<0.01),HDL-C、SOD和SIRT1、AMPK、PGC-1α蛋白表达均明显降低(P<0.01),肝脏组织肝索排列紊乱,肝细胞间隙不清晰,呈脂肪变性改变。与模型组比较,莓茶低剂量组、莓茶高剂量组FBG、FINS、HOMA-IR、TG、MDA均明显降低(P<0.05,P<0.01),SOD和SIRT1、AMPK、PGC-1α蛋白表达均明显升高(P<0.05,P<0.01),肝脏组织肝索排列相对整齐,脂肪变性得到改善;莓茶高剂量组AUC、TC均明显降低(P<0.05),HDL-C明显升高(P<0.05)。与莓茶低剂量组比较,莓茶高剂量组FBG、AUC、FINS、TC、MDA均明显降低(P<0.05),SIRT1、AMPK、PGC-1α蛋白表达均明显升高(P<0.05)。结论莓茶提取物能在一定程度上改善T2DM大鼠糖脂代谢,减轻胰岛素抵抗,其机制可能与改善氧化应激,调节肝脏SIRT1、AMPK、PGC-1α蛋白表达有关。

2型糖尿病合并结直肠癌患者癌组织中Ras ERK1/2蛋白表达及意义

目的:研究目的通过检测2型糖尿病合并结直肠癌中Ras-ERK1/2信号表达水平,分析它们与淋巴结转移的关系及其与生存状况的相关性。方法:选择石家庄市人民医院2019年3月到2021年1月期间行结肠癌手术治疗患者59例,按是否同时伴发糖尿病,分为糖尿病组(n=29)和非糖尿病组(n=30)。通过免疫组织化学方法检测两组患者手术切除的癌组织中Ras、ERK1/2蛋白的表达水平。运用Log-rank法分析不同表达情况下淋巴结转移的差异。所有患者随访36个月,统计并比较两组间患者的生存情况,采用spearman相关性分析法分析Ras、ERK1/2表达与生存期相关性。结果:Ras、ERK1/2在结直肠癌组和结直肠癌合并2型糖尿病中均有表达,且主要集中在癌细胞浆中;与非糖尿病组相比,结直肠癌合并2型糖尿病组中Ras、ERK1/2阳性表达率显著升高(P<0.05);结直肠癌合并2型糖尿病组患者淋巴结转移率较单纯结直肠癌组明显升高(P<0.05);与Ras、ERK1/2阴性表达组相比,Ras、ERK1/2阳性表达组患者的淋巴结转移率明显升高(P<0.05)。经spearman相关性分析结果显示,结直肠癌患者Ras、ERK1/2蛋白表达与中位生存时间呈负相关(P<0.05)。结论:Ras-ERK1/2蛋白阳性表达与淋巴结转移正相关,与患者生存期呈负相关,可将其作为早期诊断结直肠癌、判断预后的重要靶点。

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。

Glucocorticoid modulation of extracellular signal-regulated protein kinase 1/2 and p38 in human ovarian cancer HO-8910 cells

Objective To investigate the signaling pathway through testing the effects of dexamethasone (Dex) on the activation of the extracellular signal-regulated protein kinase 1/2 (ERK1/2) and p38 kinase (p38) in HO-8910 cells.Methods Activation of the ERK1/2 and p38 was detected by Western blotting using the antibodies against the total ERK1/2 and p38 mitogen-activated protein kinases (MAPKs) protein and the phosphorylated forms of them. Results Dex could suppress the activation of ERK1/2, while enhance the activation of p38 rapidly and strongly in a dose- and time- dependent manner. Neither effect could be blocked by RU486, the antagonist of glucocorticoid receptor (GR).Conclusion Dex has rapid effects on the activation of ERK1/2 and p38, and these effects are not mediated by GR.

Synthetic lethal short hairpin RNA screening reveals that ring finger protein 183 confers resistance to trametinib in colorectal cancer cells

Background: The mitogen-activated extracellular signal-regulated kinase 1/2(MEK1/2) inhibitor trametinib has shown promising therapeutic effects on melanoma, but its efficacy on colorectal cancer(CRC) is limited. Synthetic lethality arises with a combination of two or more separate gene mutations that causes cell death, whereas individual mutations keep cells alive. This study aimed to identify the genes responsible for resistance to trametinib in CRC cells,using a synthetic lethal short hairpin RNA(shRNA) screening approach.Methods: We infected HT29 cells with a pooled lentiviral shRNA library and applied next-generation sequencing to identify shRNAs with reduced abundance after 8-day treatment of 20 nmol/L trametinib. HCT116 and HT29 cells were used in validation studies. Stable ring finger protein 183(RNF183)-overexpressing cell lines were generated by pcDNA4-myc/his-RNF183 transfection. Stable RNF 183-knockdown cell lines were generated by infection of lentiviruses that express RNF183 shRNA, and small interference RNA(siRNA) was used to knock down RNF183 transiently.Quantitative real-time PCR was used to determine the mRNA expression. Western blotting, immunohistochemical analysis, and enzyme-linked immunosorbent assay(ELISA) were used to evaluate the protein abundance. MTT assay,colony formation assay, and subcutaneous xenograft tumor growth model were used to evaluate cell proliferation.Results: In the primary screening, we found that the abundance of RNF183 shRNA was markedly reduced after treatment with trametinib. Trametinib induced the expression of RNF183, which conferred resistance to drug-induced cell growth repression and apoptotic and non-apoptotic cell deaths. Moreover, interleukin-8(IL-8) was a downstream gene of RNF183 and was required for the function of RNF183 in facilitating cell growth. Additionally, elevated RNF183 expression partly reduced the inhibitory effect of trametinib on IL-8 expression. Finally, xenograft tumor model showed the synergism of RNF183 knockdown and trametinib in repressing the growth of CRC cells in vivo.Conclusion: The RNF183-IL-8 axis is responsible for the resistance of CRC cells to the MEK1/2 inhibitor trametinib and may serve as a candidate target for combined therapy for CRC.

PMS2通过ERK/ERCC1通路对结肠癌SW480细胞生物学行为的影响

目的:探讨减数分裂后分离蛋白2(PMS2)表达对结肠癌SW480细胞生物学行为的影响,阐明PMS2与切除修复交叉互补组1(ERCC1)和细胞外调节蛋白激酶(ERK)信号转导通路的关系。方法:将PMS2 siRNA质粒和PMS2过表达质粒分别转染入结肠癌SW480细胞(分别为PMS2敲减组和PMS2过表达组),同时设PMS2敲减对照组(siRNA-NC组)和PMS2过表达对照组(PMS2 control组)。采用实时荧光定量PCR(RT-qPCR)法检测各组细胞中PMS2 mRNA表达水平,Western blotting法检测各组细胞中PMS2蛋白表达水平,CCK-8法检测各组细胞增殖活性,细胞划痕实验检测各组细胞迁移率,Transwell小室实验检测各组细胞中侵袭细胞数,流式细胞术检测顺铂作用后各组细胞凋亡率。通过String数据库,对PMS2、ERCC1和ERK上下游蛋白的关系进行生物信息学分析。SW480细胞分别采用3条siRNA进行PMS2和ERCC1敲减,采用RT-qPCR法验证PMS2与ERCC1的相互作用,采用Western blotting法检测各组细胞中PMS2、细胞外调节蛋白激酶1/2(ERK1/2)和磷酸化ERK1/2(p-ERK1/2)蛋白表达水平。结果:RT-qPCR法和Western blotting法检测,PMS2基因敲减和过表达细胞模型构建成功。与siRNA-NC组比较,PMS2敲减组细胞增殖活性和细胞迁移率明显升高(P<0.05或P<0.01),侵袭细胞数明显增加(P<0.01),顺铂作用后细胞凋亡率明显降低(P<0.01);与PMS2 control组比较,PMS2过表达组细胞增殖活性和细胞迁移率明显降低(P<0.01),侵袭细胞数明显减少(P<0.01),顺铂作用后细胞凋亡率明显升高(P<0.01)。蛋白-蛋白互作(PPI)富集P值为2.09e-07,包含ERCC1和ERK1/2等相互作用节点数共有13个,提示PMS2、ERCC1和ERK1/2之间可能存在调控作用。与siRNA-NC组比较,各PMS2敲减组细胞中ERCC1 mRNA表达水平明显降低(P<0.05或P<0.01);与siERCC1-NC组比较,各ERCC1敲减组细胞中PMS2 mRNA表达水平差异无统计学意义(P>0.05)。与siRNA-NC组比较,PMS2敲减组细胞中PMS2、ERK1/2和p-ERK1/2蛋白表达水平均明显降低(P<0.05或P<0.01);与PMS2 control组比较,PMS2过表达组细胞中PMS2、ERK1/2和p-ERK1/2蛋白表达水平均明显升高(P<0.01)。结论:PMS2表达可影响结肠癌SW480细胞增殖、迁移、侵袭和抗凋亡能力。PMS2与ERCC1存在互相作用关系,并可通过调节ERCC1参与ERK信号转导通路。

沉默信息调节因子2相关酶1对乳脂、乳蛋白合成和乳腺炎的调节及其可能机制

沉默信息调节因子2相关酶1(SIRT1)是Sirtuins家族成员,可以对染色质和非组蛋白进行去乙酰化,在乳脂、乳蛋白合成以及乳腺炎的调控中发挥重要作用。本文主要综述了SIRT1通过AMP依赖的蛋白激酶(AMPK)、蛋白酪氨酸激酶-2(JAK2)、哺乳动物雷帕霉素靶蛋白(mTOR)和核转录因子-κB(NF-κB)等信号通路调控奶牛乳脂、乳蛋白合成以及乳腺炎的分子机制,以期为奶牛在乳脂、乳蛋白合成以及乳腺炎的靶向治疗提供理论支撑。

Correlation between receptor-interacting protein 140 expression and directed differentiation of human embryonic stem cells into neural stem cells

Overexpression of receptor-interacting protein 140（RIP140） promotes neuronal differentiation of N2 a cells via extracellular regulated kinase 1/2（ERK1/2） signaling.However,involvement of RIP140 in human neural differentiation remains unclear.We found both RIP140 and ERK1/2 expression increased during neural differentiation of H1 human embryonic stem cells.Moreover,RIP140 negatively correlated with stem cell markers Oct4 and Sox2 during early stages of neural differentiation,and positively correlated with the neural stem cell marker Nestin during later stages.Thus,ERK1/2 signaling may provide the molecular mechanism by which RIP140 takes part in neural differentiation to eventually affect the number of neurons produced.

白蛋白结合型紫杉醇对肺鳞癌H520细胞株PD-L1、ERK、p-ERK的调控作用观察

目的探讨白蛋白结合型紫杉醇(ab-PTX)对肺鳞癌H520细胞株的程序性死亡蛋白1配体(PD-L1)表达的影响及其可能的作用机制。方法(1)本研究采用的ab-PTX浓度及作用时间的确定:用0.001、0.01、0.1、1、10μmol/L ab-PTX培养H520细胞株24、36、48 h,计算细胞增殖抑制率,最终选择细胞增殖抑制作用最显著的48 h及其对应的ab-PTX IC50值(1.221μmol/L)进行后续试验。(2)给予不同浓度ab-PTX培养后H520细胞株PD-L1表达观察:培养基中加入0、0.001、0.01、0.1、1、10μmol/L ab-PTX体外培养肺鳞癌H520细胞株48 h(基于(1)中确定的ab-PTX作用时间),采用流式细胞术测算PD-L1阳性细胞率,采用qRT-PCR法检测PD-L1 mRNA。(3)单独或联合给予ab-PTX、细胞外调节蛋白激酶(ERK)抑制剂培养后ERK、p-ERK的表达观察:将H520细胞株分为Control组、abPTX组、PD98059(ERK抑制剂)]组、TPA(ERK激活剂)组、ab-PTX联合PD98059组、ab-PTX联合TPA组,ab-PTX组加入1.221μmol/L ab-PTX(基于(1)中确定的ab-PTX浓度);PD98059组加入50μmol/L PD98059;TPA组加入50nmol/LTPA;ab-PTX+PD98059组加入1.221μmol/Lab-PTX和50μmol/LPD98059;ab-PTX+TPA组加入1.221μmol/L ab-PTX和50 nmol/L TPA,培养48 h,流式细胞术测算PD-L1阳性细胞率,Western blotting法检测ERK、p-ERK。结果(1)不同浓度ab-PTX培养后H520细胞株PD-L1表达:采用0、0.001、0.01、0.1、1、10μmol/L ab-PTX培养的H520细胞株PD-L1阳性细胞率分别为33.9%±1.1%、39.5%±2.7%、52.6%±3.3%、60.3%±3.4%、69.9%±2.3%、77.8%±2.2%,PD-L1 mRNA相对表达量分别为1.06±0.07、1.65±0.22、2.12±0.16、3.25±0.11、3.79±0.14、4.45±0.28,随着ab-PTX浓度的增加,PD-L1阳性细胞率、PD-L1 mRNA相对表达量逐渐上升(P均<0.05)。(2)单独或联合给予ab-PTX、ERK抑制剂培养后ERK、p-ERK的表达及PD-L1阳性细胞率:与Control组相比,ab-PTX组p-ERK相对表达量升高,PD98059组p-ERK相对表达量降低,TPA组p-ERK相对表达量升高;ab-PTX联合PD98059组较ab-PTX组p-ERK相对表达量降低,较PD98059组p-ERK相对表达量升高;ab-PTX联合TPA组较ab-PTX组及TPA组p-ERK相对表达量升高(P均<0.05)。与Control组相比,ab-PTX组PD-L1阳性细胞率升高;与ab-PTX组比较,ab-PTX联合PD98059组PD-L1阳性细胞率降低;与PD98059组比较,ab-PTX联合PD98059组PD-L1阳性细胞率升高;与ab-PTX组及TPA组比较,ab-PTX联合TPA组PD-L1阳性细胞率升高(P均<0.05)。结论ab-PTX可上调H520细胞株PD-L1表达,一定范围内呈剂量依赖性;ab-PTX上调PD-L1表达的作用机制可能部分与ERK信号通路激活有关。

脑和肌肉ARNT样蛋白1、周期昼夜节律调节因子2、Notch1、糖原合成酶激酶-3β在结直肠腺癌组织中的表达及意义

目的探讨脑和肌肉ARNT样蛋白1(BMAL1)、周期昼夜节律调节因子2(PER2)、Notch1、糖原合成酶激酶-3β(GSK-3β)在结直肠腺癌组织中的表达及意义。方法实时荧光定量逆转录聚合酶链反应(RT-PCR)检测11例结直肠癌患者手术切除的新鲜结直肠癌组织及相应癌旁组织中BMAL1、PER2、Notch1、GSK-3βmRNA的相对表达量;免疫组化法检测50例手术切除的结直肠腺癌及癌旁组织、30例经内镜切除的结直肠腺瘤组织中BMAL1、PER2、Notch1、GSK-3β蛋白的表达情况。结果结直肠癌组织中,BMAL1、PER2 mRNA的相对表达量均低于癌旁组织,差异均有统计学意义(P﹤0.05);结直肠癌组织和癌旁组织中Notch1、GSK-3βmRNA的相对表达量比较,差异均无统计学意义(P﹥0.05)。免疫组化结果显示,结直肠腺癌组织、结直肠腺瘤组织及结直肠腺癌癌旁组织中,BMAL1、PER2的表达呈递增趋势,而Notch1、GSK-3β的表达呈递减趋势。淋巴结转移、TNM分期为Ⅲ~Ⅳ期结直肠腺癌患者结直肠腺癌组织中BMAL1、Notch1蛋白表达均高于无淋巴结转移、TNM分期为Ⅰ~Ⅱ期患者(P﹤0.05);病理类型为黏液腺癌的结直肠腺癌组织中PER2蛋白的表达高于管状腺癌(P﹤0.05),GSK-3β的表达低于管状腺癌(P﹤0.05)。Spearman相关分析结果显示,结直肠癌组织中BMAL1的表达与PER2的表达呈正相关(r=0.332,P=0.018),PER2的表达与GSK-3β的表达呈负相关(r=-0.291,P=0.040),Notch1的表达与GSK-3β的表达呈正相关(r=0.285,P=0.045),其余指标间的表达无相关性。结论BMAL1、Notch信号通路、GSK-3β均可能参与调控结直肠癌的发生、发展过程,且GSK-3β可能与BMAL1和Notch信号通路之间存在相互调控作用。

单核细胞趋化蛋白1对肺癌A549细胞迁移和侵袭的影响及其机制

目的:探讨单核细胞趋化蛋白1(MCP-1)对肺癌A549细胞迁移和侵袭的影响,并阐明其作用机制。方法:采用免疫组织化学法检测80例非小细胞肺癌(NSCLC)及癌旁正常肺组织中MCP-1蛋白表达情况。体外培养人肺癌A549细胞,MCP-1-小干扰RNA(siRNA)实验分为空白组、阴性对照组(si-NC组)、MCP-1-siRNA-1组和MCP-1-siRNA-2组;MCP-1过表达实验分为对照组、空载对照组(OE-NC组,转染MCP-1过表达空载质粒)、过表达MCP-1组(OE-MCP-1组,转染MCP-1过表达质粒)、过表达MCP-1+细胞外调节蛋白激酶(ERK)信号通路抑制剂PD98059组(OE-MCP-1+PD98059组,共转染MCP-1过表达质粒和PD98059)和PD98059组(转染PD98059)。分别将MCP-1-siRNA和质粒转染至肺癌A549细胞,Western blotting法验证各组A549细胞转染效率。细胞划痕实验和Transwell小室实验观察各组A549细胞迁移率和侵袭细胞数,Western blotting法检测各组A549细胞中磷酸化ERK(p-ERK)、总ERK(t-ERK)和上皮-间质转化(EMT)相关蛋白表达水平。结果:与癌旁组织比较,NSCLC组织中MCP-1蛋白阳性表达率明显升高(P<0.05);NSCLC组织中MCP-1蛋白表达水平与TNM分期和淋巴结转移有关联(P<0.05)。与si-NC组比较,MCP-1-siRNA-1组和MCP-1-siRNA-2组A549细胞中MCP-1蛋白表达水平均明显降低(P<0.01);与对照组和OE-NC组比较,OE-MCP-1组A549细胞中MCP-1蛋白表达水平明显升高(P<0.01)。细胞划痕实验,与si-NC组比较,MCP-1-siRNA-1组和MCP-1-siRNA-2组细胞迁移率均明显降低(P<0.01);与OE-NC组比较,OE-MCP-1组细胞迁移率明显升高(P<0.01);与OE-MCP-1组比较,OE-MCP-1+PD98059组细胞迁移率明显降低(P<0.01);与OE-MCP-1+PD98059组比较,PD98059组细胞迁移率明显降低(P<0.01)。Transwell小室实验,与si-NC组比较,MCP-1-siRNA-1组和MCP-1-siRNA-2组侵袭细胞数明显减少(P<0.01);与OE-NC组比较,OE-MCP-1组侵袭细胞数明显增加(P<0.01);与OE-MCP-1组比较,OE-MCP-1+PD98059组侵袭细胞数明显减少(P<0.01);与OE-MCP-1+PD98059组比较,PD98059组侵袭细胞数明显减少(P<0.01)。Western blotting法,与si-NC组比较,MCP-1-siRNA-1组和MCP-1-siRNA-2组A549细胞中p-ERK、波形蛋白(Vimentin)和N-钙黏蛋白(N-cadherin)表达水平均明显降低(P<0.05或P<0.01),E-钙黏蛋白(E-cadherin)表达水平均明显升高(P<0.01);与OE-NC组比较,OE-MCP-1组A549细胞中p-ERK、Vimentin和N-cadherin蛋白表达水平均明显升高(P<0.01),E-cadherin蛋白表达水平均明显降低(P<0.01);与OE-MCP-1组比较,OE-MCP-1+PD98059组A549细胞中p-ERK、Vimentin和N-cadherin蛋白表达水平均明显降低(P<0.01),E-cadherin蛋白表达水平均明显升高(P<0.05);与OE-MCP-1+PD98059组比较,PD98059组A549细胞中p-ERK、 Vimentin和N-cadherin蛋白表达水平均明显降低(P<0.05或P<0.01),E-cadherin蛋白表达水平明显升高(P<0.01)。结论:MCP-1蛋白可上调肺癌A549细胞中EMT相关蛋白表达,促进肺癌A549细胞的迁移和侵袭,其作用机制与激活ERK信号通路有关。

CX3CR1对创伤性骨髓炎大鼠骨骼肌微纤维、ERK/MAPK信号通路及炎症反应的影响

目的探索CX3CR1对创伤性骨髓炎大鼠骨骼肌微纤维、ERK/MAPK信号通路及炎症反应的影响。方法选取30只SPF级SD雄性大鼠,依据随机数字表法分为健康组、模型组、CX3CR1抑制组,每组10只。除健康组外,其余各组均建立创伤性骨髓炎模型。其中健康组、模型组大鼠均每日常规腹腔注射生理盐水,CX3CR1干预组向残腔内注射CX3CR1中和抗体进行处理。采用ELISA法检测血清中IL-6、IL-10、IL-1β、TGF-β水平,应用改良X线Norden评分检测骨骼肌微纤维,HE染色观察病理变化,免疫印迹及PCR检测股骨组织中细胞外信号调节蛋白激酶(Extracellular regulated protein kinase,ERK1/2)、丝裂原活化蛋白激酶(Mitogen activated protein kinase,MAPK)蛋白及mRNA表达。结果与健康组比较,模型组TGF-β、IL-1β、IL-10、IL-6等炎症因子含量均升高(P<0.05);与模型组比较,CX3CR1抑制组炎症因子含量降低(P<0.05)。与健康组比较,模型组随时间推移X线Norden评分升高(P<0.05);与模型组比较,CX3CR1抑制组X线Norden评分降低(P<0.05)。HE染色显示,健康组骨质完好;模型组可见大量炎性细胞浸润、灶性脓肿及坏死灶;CX3CR1抑制组大鼠的骨质明显改善,炎症反应降低。与健康组比较,模型组ERK1/2、MAPK蛋白及mRNA表达升高(P<0.05);与模型组比较,CX3CR1抑制组ERK1/2、MAPK蛋白及mRNA表达降低(P<0.05)。结论抑制CX3CR1可改善创伤性骨髓炎大鼠的疾病反应,可能与降低炎症反应、ERK/MAPK信号通路以及改善骨骼肌微纤维相关。

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.

靶向ERK2抑制剂的活性筛选与机理研究

细胞外信号调节激酶2(Extracellular Signal-RegulatedKinase 2,ERK2)是恶性肿瘤发生、发展过程中的关键激酶,目前还没有靶向ERK2的药物获批上市。本研究旨在获得结构新颖的靶向ERK2小分子抑制剂。通过质粒构建、蛋白表达与体外激酶活性测试,对本实验室构建的北部湾次级代谢产物及化学合成化合物库中的化合物开展生物活性筛选,利用分子对接阐明化合物与ERK2的结合模式及作用机理。试验最终筛选获得6-甲氧基红镰霉素B、异红镰霉素及嘧啶脲类等5个具有较高抑制活性的化合物(统一命名为化合物1-5),其半抑制浓度(IC50)分别为(4.17±1.82)、(13.39±0.93)、(27.85±2.55)、(19.14±1.02)和(8.55±3.72)μmol/L。化合物1-5对ERK2具有抑制活性,它们与ERK2中的LYS-54、MET-108及GLN-105残基形成的氢键是影响两者结合稳定性的关键因素。