CREB 和NF-κB在p38MAPK所致脊髓星形胶质细胞活化中的作用

目的:探讨CREB和NF-κB在p38MAPK所致脊髓星形胶质细胞活化中的作用,明确脊髓星形胶质细胞活化中p38MAPK细胞信号转导途径的作用。方法:分离培养SPF大鼠脊髓星形胶质细胞,设正常组、SP刺激组(SP组,10-7mol/L)、SP刺激+SB203580(10μmol/L)阻断p38MAPK组(SP+SB组)、SP刺激+PD98059(10μmol/L)阻断CREB组(SP+PD组)、SP刺激+SN50(10μmol/L)阻断NF-κB(SP+SN组)。WB法、免疫荧光法、ELISA法检测12 h和24 h时p-p38、p-CREB、NF-κBp65水平及GFAP、TNF-、IL-1β水平变化。结果:SP组脊髓星形胶质细胞p-p38、p-CREB、NF-κBp65显著升高,GFAP水平显著增高,同时TNF-和IL-1β水平显著增高。与SP组比较,用SB203580阻断p38MAPK通路后,SP+SB组p-p38、p-CREB、NF-κBp65显著降低,GFAP、TNF-和IL-1β水平显著降低。用PD98059阻断CREB通路后,SP+PD组p-p38、NF-κBp65无显著变化,p-CREB显著降...     

p38 MAPK介导高糖诱导的肾小管上皮细胞向间充质细胞转变

本文旨在观察p38MAPK与高糖诱导的肾小管上皮细胞向间充质细胞转变之间的关系。将雄性Sprague—Dawley（SD）大鼠随机分为对照组、糖尿病组、胰岛素治疗组,用免疫组织化学、Western blot检测p38MAPK和磷酸化p38MAPK（P—p38MAPK）蛋白表达。采用机械分离和酶消化获取SD大鼠肾小管节段,进行肾小管上皮细胞培养,将肾小管上皮细胞分为对照组、高渗组（20mmol／L D—mannitol）、高糖组（20mmol／L D—glucose）和SB202190（p38MAPK特异性抑制剂）＋高糖组,处理72h后收集细胞,用免疫细胞化学检测α-平滑肌肌动蛋白（α—smooth muscleactin,α-SMA）、p-p38MAPK和Snaill蛋白表达,Western blot检测p38MAPK、p-p38MAPK、Snaill、转化生长因子β1（transforming growth factor—β1,TGF-β1）、α-SMA和E-cadherin的表达,RT-PCR检测α-SMA和E-cadherin mRNA的表达。体内和体外结果均显示,高糖状态激活了p38MAPK,这种活化作用在体内可因胰岛素控制血糖而被消除,在体外可被p38MAPK特异性抑制剂SB202190显著抑制;高糖组α-SMA蛋白和mRNA在原代培养肾小管上皮细胞的表达较对照组分别增加12倍和8倍（P〈0．01）,SB202190处理组其表达则较高糖组分别减少67％和50％（P〈0．01）。SB202190不影响TGF—β1蛋白表达,但下调Snaill蛋白表达,并部分恢复高糖组E—cadherin蛋白和mRNA的表达。上述结果提示,p38MAPK可能通过转录因子Snaill介导高糖诱导的肾小管上皮细胞向间充质细胞转变。     

高糖对大鼠血管平滑肌细胞表型转化的影响及其机制

目的:探讨高糖对大鼠血管平滑肌细胞(VSMCs)表型转化的影响及机制。方法:大鼠VSMCs由组织贴壁法培养获得,以3~5代细胞为靶细胞,待细胞融合后用含有2%胎牛血清的DMEM孵育12 h,再置于正常组(5.5 mmol/L glucose)、高糖(25 mmol/L glucose)、高糖+P38抑制剂SB203580的DMEM继续培养24 h。用实时荧光定量RT-PCR分析各组VSMCs合成型标志蛋白OPN、收缩型标志蛋白α-SMA及基质金属蛋白酶MMP-2、MMP-9的基因表达情况;Western blot检测各组OPN、α-SMA和磷酸化P38的蛋白表达情况。结果:1高糖促进了VSMCs的表型由收缩型转化为合成型,同时上调基质金属蛋白酶MMP-2和MMP-9的表达;2高糖能促进P38蛋白的磷酸化,增加磷酸化P38的蛋白表达量;3P38/MAPK信号通路抑制剂SB203580明显抑制了高糖促进VSMCs表型转化及MMP-2、MMP-9表达的效应。结论:高糖能通过P38/MAPK信号通路促进VSMCs的表型转化。     

CREB和NF-κB在p38MAPK所致脊髓星形胶质细胞活化中的作用（英文）

目的：探讨CREB和NF-κB在p38MAPK所致脊髓星形胶质细胞活化中的作用,明确脊髓星形胶质细胞活化中p38MAPK细胞信号转导途径的作用。方法：分离培养SPF大鼠脊髓星形胶质细胞,设正常组、SP刺激组（SP组,10-7mol/L）、SP刺激＋SB203580（10μmol/L）阻断p38MAPK组（SP＋SB组）、SP刺激＋PD98059（10μmol/L）阻断CREB组（SP＋PD组）、SP刺激＋SN50（10μmol/L）阻断NF-κB（SP＋SN组）。WB法、免疫荧光法、ELISA法检测12 h和24 h时p-p38、p-CREB、NF-κBp65水平及GFAP、TNF-、IL-1β水平变化。结果：SP组脊髓星形胶质细胞p-p38、p-CREB、NF-κBp65显著升高,GFAP水平显著增高,同时TNF-和IL-1β水平显著增高。与SP组比较,用SB203580阻断p38MAPK通路后,SP＋SB组p-p38、p-CREB、NF-κBp65显著降低,GFAP、TNF-和IL-1β水平显著降低。用PD98059阻断CREB通路后,SP＋PD组p-p38、NF-κBp65无显著变化,p-CREB显著降低,GFAP水平降低,同时TNF-和IL-1β水平降低。用SN50阻断NF-κB通路后,SP＋SN组p-p38、p-CREB无显著变化,NF-κBp65显著降低,GFAP水平降低,同时TNF-和IL-1β水平降低。结论：体外培养中,SP刺激后脊髓星形胶质细胞显著活化,p38MAPK活化后通过CREB及NF-κB信号途径导致胶质细胞炎性因子水平显著升高。     

CaSR表达在大鼠糖尿病性肝硬化损伤和纤维化发生中的作用

目的:观察钙敏感受体(CaSR)在糖尿病性肝损伤发生中的作用。方法:本实验分别制备糖尿病大鼠和高糖处理HSC系大鼠肝星形细胞模型。40只Wistar大鼠随机分为正常对照组(Control,n=10),糖尿病组(T1D,STZ 60 mg/kg 一次性腹腔注射,n=30),造模成功后分别在2、4、8周检测大鼠的体重、血糖、血清中谷草转氨酶(AST)和谷丙转氨酶(ALT)活性,观察形态学和超微结构改变,以及Western blot检测CaSR和肝纤维化相关指标表达的变化。HSC系大鼠肝星形细胞随机分为正常对照组(Control,10% FBS-DMEM + 5.6 mmol/L葡萄糖),高糖组(HG,10% FBS-DMEM + 40 mmol/L葡萄糖下培养48 h)和CaSR抑制剂组(HG+Calhex₂₃₁,10% FBS-DMEM + 40 mmol/L葡萄糖 + 2.5μmol/L CaSR抑制剂(Calhex₂₃₁)下培养48 h,每组n=5)。结果:动物模型中,与正常组相比,糖尿病大鼠体重减轻,血糖、AST和ALT显著升高,CaSR和胶原Ⅰ(COⅠ)、胶原Ⅲ(COⅢ)、基质金属蛋白酶1(MMP1)、基质金属蛋白酶2(MMP2)、基质金属蛋白酶9(MMP9)蛋白表达上调;细胞模型结果与大体基本一致,与正常组相比,高糖组细胞分化标志性蛋白α-平滑肌肌动蛋白(α-SMA)表达增加,表明HSC分化成肌成纤维细胞,细胞外间质(ECM)主要成分COⅠ和COⅢ表达增加,降解ECM的关键酶MMP9同样增加,Calhex₂₃₁可减轻上述变化。结论:CaSR表达上调参与大鼠糖尿病性肝损伤和纤维化的发生。     

高糖诱导肾小球系膜细胞表达TNFα-的机制探讨

目的:初步探讨高糖诱导肾小球系膜细胞表达肿瘤坏死因子α(TNFα-)的机制。方法:分别用p38丝裂原活化蛋白激酶(p38MAPK)特异性抑制剂SB203580、核因子-κB(NFκ-B)特异性抑制剂PDTC预刺激肾小球系膜细胞30 min,再以高糖(20 mmol/L)干预48 h后,分别采用RT-PCR法检测系膜细胞内TNFα-mRNA水平,Western blot法检测系膜细胞内磷酸化p38MAPK蛋白水平、细胞核及细胞浆NFκ-B p65蛋白水平。结果:与低糖对照组相比,高糖可促进肾小球系膜细胞内TNFα-mRNA表达,以及p38MAPK、NFκ-B蛋白活化;SB203580(10 mmol/L)、PDTC(10 mmol/L)预刺激肾小球系膜细胞均可抑制高糖诱导肾小球系膜细胞表达TNFα-,且SB203580可抑制高糖诱导系膜细胞内NFκ-B蛋白活化。结论:p38MAPK-NFκ-B信号途径参与介导高糖诱导肾小球系膜细胞表达TNFα-。     

阿柏西普减轻高糖诱导的视网膜色素上皮细胞损伤和PI3K/AKT信号通路活化

目的 探究阿柏西普(aflibercept,ABC)对高糖诱导的视网膜色素上皮细胞损伤的影响及可能机制.方法 取人视网膜色素上皮细胞APRE-19,并随机分为对照组、高糖组(HG)和HG+ABC组.其中对照组细胞常规培养,HG组细胞用30mmol/L葡萄糖培养液培养,HG+ABC组细胞用30mmol/L葡萄糖和2mg/...     

SB239063通过抑制TNF-α和p38MAPK，减轻香烟烟雾暴露变应性鼻炎大鼠MKP-1的表达

摘要 目的：探讨p38MAPK抑制剂SB239063对香烟烟雾暴露变应性鼻炎大鼠p38MAPK信号通路、TNF-α、MKP-1表达的影响。方法：先构建变应性鼻炎（AR）大鼠模型,然后给予AR大鼠被动吸入香烟烟雾（CS）,再行腹腔注射AR大鼠SB239063（100 mg/kg）,分为AR组、AR+CS组、AR+CS+SB239063组。造模后对各组大鼠进行症状学评分;苏木精-伊红（HE）染色法观察大鼠鼻黏膜的形态学变化;实时荧光定量PCR（RT-PCR）检测鼻黏膜p38MAPK、MKP-1 mRNA的表达水平;酶联免疫吸附试验(ELISA)分析外周血、脾脏TNF-α的含量;Western blots检测鼻黏膜p38MAPK、p-p38MAPK、MKP-1蛋白的表达水平。结果：与AR组比较,AR+CS组大鼠的过敏症状（P<0.05）加重;鼻黏膜嗜酸性粒细胞（P<0.05）、中性粒细胞浸润（P<0.01）增多; MKP-1 mRNA及其蛋白的表达水平均升高（P<0.001）;外周血、脾脏TNF-α的表达水平升高（P<0.001）;p-p38MAPK蛋白的表达水平升高（P<0.001）。与AR+CS组比较,AR+CS+SB239063组大鼠过敏症状评分下降（P<0.01）;鼻黏膜中嗜酸性粒细胞、中性粒细胞计数下降（P值均< 0.05）;p38MAPK mRNA的表达水平降低（P<0.05）,MKP-1 mRNA及其蛋白的表达水平下降（P<0.001）;外周血、脾脏TNF-α的表达水平降低（P值均< 0.001）;p38MAPK、p-p38MAPK蛋白的表达水平降低,差异均具有显著统计学意义（P值均 < 0.001）。结论：SB239063通过抑制TNF-α、p38MAPK及其自磷酸化,减轻香烟烟雾暴露变应性鼻炎大鼠MKP-1的表达。     

高糖对线粒体乙醛脱氢酶2在大鼠心肌成纤维细胞中表达的影响

目的：观察心肌成纤维细胞是否存在线粒体乙醛脱氢酶2（ALDH2）的表达,探讨ALDH2在高糖诱导的心肌成纤维细胞引起纤维化发生中的作用。方法：原代培养心肌成纤维细胞,分为正常对照组（5.5 mmol/L）、正常+ALDH2激动剂Alda-1（20μmol/L）组、高糖组（30 mmol/L）、高糖+ Alda-1组。免疫荧光鉴定心肌成纤维细胞。各组细胞分别培养48 h后应用MTT法检测成纤维细胞增殖活力,RT-PCR和Western blot检测ALDH2 mRNA及蛋白的表达。结果：RT-PCR和Western blot结果显示心肌成纤维细胞ALDH2 mRNA和蛋白均有表达。与正常对照组相比,高糖组心肌成纤维细胞增殖能力提高（P < 0.01）,ALDH2蛋白表达下降（P < 0.05）;与高糖组相比,高糖+ Alda-1组心肌成纤维细胞增殖能力降低（P < 0.01）,ALDH2的蛋白表达增加（P < 0.05）。结论：心肌成纤维细胞存在ALDH2的表达,ALDH2激动剂Alda-1提高ALDH2的表达后可以抑制高糖引起的心肌成纤维细胞的增殖。     

精胺对高糖引起的大鼠心肌纤维化的影响及其机制

目的: 观察精胺对糖尿病心肌病(DCM)及高糖处理的心肌成纤维细胞(CFs)的保护作用并探讨其机制。方法: ①动物实验:24 只雄性Wistar大鼠随机分为正常组(Control),糖尿病组(T1D)和精胺组(T1D+Sp),每组8只。采用一次性腹腔注射链脲佐菌素(STZ,60 mg/kg)复制 1 型糖尿病大鼠模型,精胺组在 STZ 注射前两周每天腹腔注射精胺(Sp,5 mg/(kg·d)),随后隔天注射,饲养至 12 周。检测各组大鼠血糖、胰岛素水平、射血分数(EF)和缩短分数(FS),并对大鼠心脏组织进行 Masson 染色和 Sirius red 染色。②细胞实验:出生1～3 d的大鼠心脏提取原代 CFs,随机分为正常组(Control),高糖组(HG)和精胺组(HG+Sp,每组 n=6)。高糖(HG,40 mmol/L)处理 CFs 复制细胞模型,精胺组在高糖处理前给予Sp(5 μmol/L)预处理30 min。CCK8检测细胞活性,ELISA法检测培养基中胶原含量,Western blot 测定细胞周期相关蛋白(PCNA、CyclinD1 及 P27)的表达。结果: 与 Control 组相比,T1D 大鼠血糖显著上升,胰岛素水平和心脏功能降低;染色结果显示心肌胶原含量增加。同时,HG 组细胞活力与培养基中胶原含量明显增加,PCNA、CyclinD1 表达上调,而 P27 表达下调。精胺能减轻上述变化,表现为改善心脏功能,调节细胞周期蛋白表达和减轻心肌纤维化水平。结论: 精胺可减轻糖尿病心肌病心肌纤维化的发生,其机制可能与调节细胞周期有关。     

Berberine reduces fibronectin and collagen accumulation in rat glomerular mesangial cells cultured under high glucose condition

Diabetic nephropathy, one of the microvascular complications of diabetes mellitus, is a leading cause of end-stage renal disease. Berberine is one of the main constituents of Coptidis Rhizoma and Cortex Phellodendri. In this study, we investigated the effects of berberine on fibronectin and collagen production, and explored the role of p38MAPK signaling pathway in rat glomerular mesangial cells cultured under high glucose condition. Six groups were divided according to the different experimental conditions: (1) Normal glucose group (NG); (2) Mannitol group (Mannitol); (3) High glucose group (HG); (4) SB203580 treatment group (HG + SB203580); (5) Berberine low dosage group (HG + BBR 30 μM); (6) Berberine high dosage group (HG + BBR 90 μM). Cell proliferation and collagen synthesis were measured by MTT and ³H-proline incorporation assay, respectively. The phospho-p38MAPK, phospho-cAMP response element binding protein (CREB) and fibronectin were detected by western blot analysis. Fibronectin protein expression and collagen synthesis were significantly increased in HG-treated group compared with normal glucose group (P < 0.05). In SB203580 treatment group and two groups of berberine, protein expression of fibronectin and collagen synthesis were obviously decreased compared with HG-treated group (P < 0.05). Berberine significantly decreased protein expression of fibronectin compared with SB203580 treatment group (P < 0.05). Berberine at high dosage significantly decreased collagen synthesis compared with SB203580 treatment group (P < 0.05). Both SB203580 and berberine significantly decreased phospho-p38MAPK and phospho-CREB level compared with HG-treated group (P < 0.05). These results indicated that berberine might inhibit fibronectin and collagen synthesis partly via p38MAPK signal pathway in rat glomerular mesangial cells exposed to high glucose.     

内皮素-1对大鼠血管平滑肌细胞产生MCP-1的影响及其机制

目的：观察内皮素-1（ET-1）对大鼠血管平滑肌细胞（VSMCs）产生单核细胞趋化蛋白-1（MCP-1）的影响及其机制。方法：培养大鼠血管平滑肌细胞（VSMCs）。细胞分为2组：ET-1刺激组：以不同浓度ET-1刺激VSMCs不同时间;阻断剂干预组：VSMCs分别与不同阻断剂[ET_AR、ET_BR阻断剂BQ123、BQ788,抗氧化剂N-乙酰半胱氨酸（NAC）,ERK、p38MAPK、JNK及NF-κB抑制剂PD98059、SB203580、SP600125及PDTC]预先孵育30 min,再加入ET-1刺激24 h。在预定时间,以酶联免疫吸附（ELISA）法、逆转录聚合酶链反应（RT-PCR）法分别测定不同因素下VSMCs MCP-1蛋白质及mRNA表达量。VSMCs分别与不同阻断剂（BQ123、BQ788、NAC、PD98059、SB203580及SP600125预先孵育20 min,再加入ET-1刺激5 min,免疫印迹（WB）法测定VSMCs胞浆中细胞外调节蛋白激酶（ERK）、p38丝裂原活化蛋白激酶（p38MAPK）、c-Jun氨基末端激酶（JNK）及其各自磷酸化蛋白质的水平。各项检测均重复3次。结果：ET-1能刺激VSMCs MCP-1蛋白质及mRNA表达,其表达量随ET-1浓度及刺激时间的增加呈升高趋势（P<0.05,P<0.01）;BQ123、NAC、PD98059、SB203580及PDTC能显著抑制ET-1诱导的大鼠VSMCs MCP-1蛋白质及mRNA表达（P<0.01）,而BQ788及SP600125对此作用无明显影响。BQ123、NAC与PD98059或SB203580能分别抑制ET-1刺激后VSMCs胞浆内ERK及p38MAPK的磷酸化（P<0.05,P<0.01）,而ET-1对JNK的磷酸化无明显激活作用。结论：ET-1通过ET_AR、ROS、ERK、p38MAPK及NF-κB诱导大鼠VSMCs产生MCP-1。     

热量限制延缓人二倍体成纤维细胞衰老的体外模型

为建立人二倍体成纤维细胞IMR 90的热量限制体外模型 ,分别采用低浓度、正常浓度和高浓度葡萄糖培养条件 ,常规传代培养IMR 90细胞 ,利用综合细胞衰老指标对模型进行评价 .低、正常和高浓度葡萄糖培养条件组IMR 90细胞平均寿限分别为 5 8 3、5 5 0和 4 7 2PDL(群体倍增水平 ) .低浓度葡萄糖培养IMR 90细胞早期增长速度有所减慢 ,但仍保持对生长因子诱导的细胞增殖能力 ,并使晚期IMR 90处于细胞周期S期的比例以及其DNA修复能力显著高于其他条件培养的晚期细胞 .低浓度葡萄糖培养IMR 90晚期细胞的半乳糖苷酶染色阳性率亦明显低于其他条件培养的晚期细胞 .实验结果表明 ,低浓度葡萄糖培养可以延缓IMR 90复制衰老 ,建立了热量限制延缓衰老体外模型 ,为进一步探讨热量限制延缓衰老作用机制的研究打下基础     

PI3K/Akt通路在高糖诱导足细胞分泌Ⅳ型胶原中的作用

目的探讨磷酸酰肌醇3激酶/蛋白激酶B（PI3K/Akt）信号通路在高糖诱导足细胞分泌Ⅳ型胶原（ColⅣ）中的作用。方法体外培养小鼠肾足细胞,给予高糖刺激（30mmol/L）处理0h、12h、24h、48h,正常糖（5mmol/L）分别培养相同时间作为对照,采用免疫细胞化学染色法和蛋白印迹法检测p-Akt、ColⅣ的表达。结果高糖可以诱导足细胞内p-Akt蛋白表达,随刺激时间延长分泌增多,24h达到高峰,各时间点相比有统计学差异（P〈0.05）;足细胞内ColⅣ蛋白表达随高糖刺激时间延长逐渐增多,并与p-Akt表达呈正相关关系（r=0.834,P=0.001）。结论高糖可能通过激活PI3K/Akt通路诱导足细胞分泌Ⅳ型胶原。     

Purinergic signaling modulates the cerebral inflammatory response in experimentally infected fish with <Emphasis Type="Italic">Streptococcus agalactiae</Emphasis>: an attempt to improve the immune response

Epigallocatechin gallate (EGCG), a bioactive ingredient of green tea, plays a protective role in the cardiovascular system. Homocysteine (Hcy) is a major risk factor for chronic kidney disease and cardiovascular disease. The present study aimed to investigate the role of EGCG in Hcy-induced proliferation of vascular smooth muscle cells (VSMCs) and its underlying mechanism. We also explored the roles of rennin-angiotensin system (RAS), extracellular signal-regulated kinases (ERK1/2), and p38 mitogen-activated protein kinase (p38 MAPK) in this process. Human aortic smooth muscle cells (HASMCs) were treated with different drugs for different periods. The proliferation rate of HASMCs was detected using the CCK-8 and BrdU labeling assays. The Western blot assay was used to determine the expression levels of angiotensin II type 1 receptor (AT-1R), ERK1/2, and p38 MAPK. Compared with the control group, the HASMCs treated with Hcy at different doses (100, 200, 500, and 1000 µM) showed significantly increased proliferation. Hcy increased the expression of AT-1R, whereas EGCG decreased the protein expression of AT-1R. Furthermore, we found that Hcy-induced expression of p-ERK1/2 and p-p38MAPK was dependent on AT-1R. Compared with Hcy (500 µM)-treated cells, EGCG (20 µM)-treated cells showed decreased proliferation as well as expression of AT-1R, p-ERK1/2, and p-p38MAPK. In addition, HASMC proliferation was suppressed by the addition of an AT-1R blocker (olmesartan), an ERK1/2 inhibitor (PD98059), and a p38MAPK inhibitor (SB202190). EGCG can inhibit AT-1R and affect ERK1/2 and p38MAPK signaling pathways, resulting in the decrease of VSMC proliferation induced by Hcy.     

Neuroprotective Effect of Oxysophocarpine by Modulation of MAPK Pathway in Rat Hippocampal Neurons Subject to Oxygen–Glucose Deprivation and Reperfusion

Oxysophocarpine (OSC), an alkaloid isolated from Sophora flavescens Ait, has been traditionally used as a medicinal agent based on the observed pharmacological effects. In this study, the direct effect of OSC against neuronal injuries induced by oxygen and glucose deprivation (OGD) in neonatal rat primary-cultured hippocampal neurons and its mechanisms were investigated. Cultured hippocampal neurons, which were exposed to OGD for 2 h followed by a 24 h reoxygenation, were used as an in vitro model of ischemia and reperfusion. 2-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and lactate dehydrogenase (LDH) assay were used to confirm neural damage and to further evaluate the protective effects of OSC. The concentration of intracellular-free calcium [Ca²⁺]_i and mitochondrial membrane potential (MMP) were measured to determine the intracellular mechanisms and to further estimate the degree of neuronal damage. Changes in expression of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, p-ERK1/2, p-JNK1/2, and p-p38 MAPK were also observed in the in vitro model. It was shown that OSC (0.8, 2, or 5 µmol/L) significantly attenuated the increased absorbance of MTT, and the release of LDH manifests the neuronal damage by the OGD/R. Meanwhile, the pretreatment of the neurons during the reoxygenation period with OSC significantly increased MMP; it also inhibited [Ca²⁺]_i the elevation in a dose-dependent manner. Furthermore, the pretreatment with OSC (0.8, 2, or 5 µmol/L) significantly down-regulated expressions of IL-1β, TNF-α, p-ERK1/2, p-JNK1/2, and p-p38 MAPK in neonatal rat primary-cultured hippocampal neurons induced by OGD/R injury. In conclusion, OSC displays a protective effect on OGD-injured hippocampal neurons by attenuating expression of inflammatory factors via down-regulated the MAPK signaling pathway.     

糖皮质激素抑制结肠癌细胞增殖和侵袭的作用机制

本研究目的是为了证实地塞米松对结肠癌LoVo细胞增殖的抑制作用,并阐明其中的分子机制。LoVo细胞经不同浓度梯度地塞米松干预,再加入TGF-β1受体抑制剂SB431542阻断TGF-β1信号传导途径,通过MTS分析各组细胞增殖情况,借助Hoechst 33342和Annexin V/PI染色法检测细胞凋亡率;结合Western blotting对TGF-β1、Smad2和caspase-3蛋白表达情况的检测结果,分析地塞米松诱导结肠癌LoVo细胞凋亡的作用机理。LoVo细胞在1.0 mmol/L和10.0 mmol/L地塞米松干预48 h后,细胞增殖率与对照组相比分别降低32%(p<0.01)和47%(p<0.001),2组细胞凋亡率分别为28%和36%(p<0.001)。Western blotting结果显示,与对照组相比,地塞米松以浓度依赖性方式显著上调LoVo细胞TGF-β1、Smad2和Cleavedcaspase-3蛋白水平(p<0.01),而TGF-β1受体抑制剂SB431542明显下调TGF-β1、Smad2和Cleaved-capase-3蛋白表达(p<0.05)。流式细胞术检测结果表明,SB431542+地塞米松干预组与地塞米松处理组LoVo细胞凋亡率分别为8%和23%(p<0.001)。地塞米松可显著诱导LoVo细胞凋亡,而SB431542能够挽救这一过程,这表明,地塞米松通过TGF-β1/Smad2通路诱导LoVo细胞凋亡。