p38 MAPK信号通路在LPS诱导RAW264.7细胞表达sTREM-1中的作用

目的探讨p38丝裂原激活蛋白激酶(p38 MAPK)信号通路在脂多糖(LPS)诱导RAW264.7细胞表达可溶性髓样细胞触发受体1(s TREM-1)中的作用。方法培养小鼠巨噬细胞株RAW264.7,采用相同浓度的LPS在不同时间诱导RAW264.7细胞,应用Western blot法分别检测p38MAPK与磷酸化p38 MAPK(p-p38MAPK)蛋白表达水平,RT-PCR法检测p38 MAPK mRNA表达水平,酶联免疫吸附(ELISA)法检测细胞培养上清液中s TREM-1表达水平。用不同浓度p38 MAPK特异性抑制剂SB203580处理细胞,观察上述指标的变化。结果 LPS可呈时间依赖性诱导RAW264.7细胞p-p38 MAPK和p38 MAPK mRNA的表达;SB203580可呈浓度依赖性抑制p-p38 MAPK和p38 MAPK mRNA的表达;SB203580阻断p38 MAPK信号转导通路后,LPS对s TREM-1表达的诱导作用受到显著抑制,并且具有剂量依赖性。结论 LPS通过p38 MAPK信号通路诱导RAW264.7细胞表达s TREM-1。     

雷公藤诱导皮肤T细胞淋巴瘤Hut102的凋亡及机制

目的探讨雷公藤内酯醇（TP）诱导皮肤T细胞淋巴瘤Hut102细胞株的凋亡及机制。方法采用MTT法检测Hut102细胞的增殖抑制率,Annexin v-FITC/PI双染流式细胞术检测Hut102细胞的凋亡率,Western印迹法检测Hut102细胞中磷酸化p38丝裂原活化蛋白激酶（p38MAPK）、caspase-3、热休克蛋白27（Hsp27）的表达。结果雷公藤内酯醇可诱导Hut102细胞凋亡（P〈0.01）,磷酸化p38MAPK、caspase-3被激活,同时抑制Hsp27的表达。用p38MAPK特异性抑制剂SB203580干预后,雷公藤内酯醇诱导Hut102细胞凋亡率下降,磷酸化p38的表达降低,caspase-3激活被抑制,Hsp27的表达增加。结论雷公藤内酯醇可诱导Hut102细胞凋亡,该作用可被p38MAPK特异性抑制剂SB203580显著抑制,提示雷公藤内酯醇可能通过激活p38MAPK信号通路使部分Hut102细胞产生凋亡。     

TNF-α 通过 p38 丝裂原活化蛋白激酶信号通路对小胶质细胞HMGB1 表达的调控作用

目的：观察P38丝裂原活化蛋白激酶(p38 mitogen-activated protein kinase,p38 MAPK)抑制剂SB203580对 TNF-α诱导的原代培养大鼠小胶质细胞高迁移率族蛋白B1(high mobility group protein B1,HMGB1)表达的影响。方法： 采用原代培养大鼠小胶质细胞,设立对照组、TNF-α组(25 ng/mL)、TNF-α(25 ng/mL)+SB 203580组(10 μmol/L)、SB 203580组(10 μmol/L),各组细胞经药物处理16 h后分别用ELISA法检测细胞培养上清中HMGB1的表达情况,Western 印迹检测细胞HMGB1和磷酸化p38MAPK表达情况,用反转录PCR检测HMGB1 mRNA表达。结果：经TNF-α刺激 后,大鼠小胶质细胞及其培养上清液中HMGB1蛋白表达增高;SB 203580可抑制TNF-α诱导的磷酸化p38 MAPK表达 (P<0.01),同时下调HMGB1mRNA和HMGB1蛋白的表达。结论：TNF-α可诱导小胶质细胞晚期炎症因子HMGB1的表 达,并且其诱导机制与p38 MAPK被快速激活相关。     

扇贝多肽抑制紫外线A波诱导的HaCaT细胞凋亡依赖p38 MAPK通路和caspase-3

目的 从p38促细胞分裂剂激活性蛋白激酶(p38 MAPK)通路和半胱天冬酶-3(caspase-3)的角度,研究扇贝多肽(polypeptide from Chfamys farreri,PCF)抑制紫外线A波(UVA)引起的HaCaT细胞凋亡的分子机制.方法 实验分为6组:对照组、UVA模型组、UVA+5.68 mmol&#183;L-1维生素C阳性对照组、UVA+5.69 mmol&#183;L-1 PCF组、UVA+2.84 mmol&#183;L-1 PCF组、UVA+1.42 mmol&#183;L-1 PCF组.以正交实验设计确立UVA诱导HaCaT细胞凋亡模型;琼脂糖凝胶电泳分析PCF、p38 MAPK抑制剂(SB203580)及caspase-3特异性抑制剂(Ac-DEVD-CHO)对细胞凋亡的影响;蛋白质印迹法检测p38 MAPK及磷酸化p38 MAPK表达;流式细胞术检测caspase-3的活性.结果 PCF能明显抑制UVA引起的HaCaT细胞凋亡;SB203580和Ac-DEVD-CHO对UVA诱导的HaCaT细胞凋亡有抑制作用;1.42～5.69 mmol&#183;L-1内的PCF可剂量依赖性抑制UVA引起的p38MAPK磷酸化及caspase-3的活化.结论 PCF可抑制UVA诱导的HaCaT细胞凋亡,其作用机制与抑制p38 MAPK通路和caspase-3活性有关.     

多聚左旋精氨酸通过p38/MAPK信号通路诱导NCI-H292细胞分泌IL-6、IL-8细胞

目的 研究多聚左旋精氨酸(PLA)诱导气道上皮细胞NCI-H292分泌炎症因子白介素-6(IL-6)和白介素-8(IL-8)的机制.方法 将NCI-H292细胞按PLA浓度分组(0、2.5、5、10、20 mg/L),采用荧光定量PCR(qRT-PCR)方法检测细胞中IL-6和IL-8 mRNA表达水平;按PLA加药时间分组(0、15、30、45、60 min),Western blot法检测p38/MAPK磷酸化水平;按对照组、PLA组、PLA+SB203580组和SB203580组分组,采用qRT-PCR法和ELISA法检测IL-6和IL-8的mRNA和蛋白表达量.结果 PLA能诱导NCI-H292细胞IL-6、IL-8 mRNA表达上调(P＜0.01),PLA也能增加NCI-H292细胞p38/MAPK磷酸化水平(P＜0.01),p38/MAPK阻断剂SB203580可抑制PLA诱导的NCI-H292细胞IL-6、IL-8 mRNA表达上调(P＜0.01)及p38/MAPK磷酸化水平的增加(P＜0.01).结论 p38/MAPK信号通路参与PLA诱导NCI-H292细胞炎症因子IL-6和IL-8 mRNA转录过程.     

白细胞介素-18促肾小管上皮细胞转分化的机制研究

目的探讨白细胞介素-18（IL-18）诱导体外培养的人近端肾小管上皮细胞转分化的细胞内信号的转导机制。方法应用细胞培养技术培养HK-2细胞。予不同浓度的p38MAPK通路特异性阻断剂SB203580预孵育细胞30min后,再加入IL-18共同培养。应用RT—PCR方法检测α-SMA mRNA的表达水平,ELISA方法测定细胞胞浆中α—SMA的表达水平。结果SB203580可呈剂量依赖性地抑制IL—18诱导的HK-2细胞α-SMA基因和蛋白的表达。结论阻断p38MAPK信号通路可明显抑制IL—18诱导的HK-2细胞转分化作用：p38MAPK通路可能是调控IL-18诱导的HK-2细胞转分化的主要信号通路之一。     

p38 MAPK信号通路介导晚期氧化蛋白产物诱导的肾小管上皮细胞间充质转分化

目的探讨p38丝裂原活化蛋白激酶（p38 MAPK）信号途径是否介导晚期氧化蛋白产物（AOPP）诱导肾小管上皮细胞间充 质转分化（EMT）。方法用次氯酸氧化牛血清白蛋白（BSA）制备的AOPP-BSA刺激体外培养的人肾小管上皮细胞（HK-2 细 胞）,用Western blotting检测细胞p38 MAPK和磷酸化p38 MAPK的表达;用p38 MAPK磷酸化抑制剂SB203580预处理细胞, 并予AOPP-BSA刺激,用Western blotting和实时荧光定量PCR分别检测EMT标志性蛋白E-cadherin、vimentin和内质网应激标 志性蛋白GRP78和mRNA表达;用内质网应激（ERS）阻断剂salubrinal预处理细胞,并予AOPP-BSA刺激,用Western blotting 检测细胞p38 MAPK和磷酸化p38 MAPK的表达。结果AOPP-BSA能使细胞p38 MAPK磷酸化;用SB203580抑制p38 MAPK 磷酸化可显著抑制AOPP-BSA下调的E-cadherin 和上调的vimentin 和GRP78 的表达;用salubrinal 抑制ERS 可有效地抑制 AOPP-BSA诱导的p38 MAPK磷酸化。结论p38 MAPK信号途径可能参与了AOPPs诱导肾小管上皮细胞发生EMT的过程,且 p38 MAPK受ERS调控。     

亚硒酸钠对大鼠肾小球系膜细胞p38MAPK和VEGF表达的调控

目的:探讨丝裂素活化蛋白激酶p38(p38MAPK)和血管内皮生长因子(VEGF)的关系,从而研究p38MAPK和VEGF在糖尿病肾病中的作用及硒在抗糖尿病肾病中的作用机制.方法:分别以高葡萄糖、糖基化终产物,高胰岛素和过氧化氢孵育大鼠肾小球系膜细胞(RMCs);以p38MAPK特异抑制剂SB203580和亚硒酸钠分别预处理RMCs,再给予上述四种刺激因素孵育RMCs,观察RMCs p38MAPK和VEGF蛋白表达.结果:高葡萄糖、糖基化终产物、高胰岛素和过氧化氢均可独立激活p38MAPK,使其磷酸化表达量增加,VEGF表达也明显增加:SB203580预处理后,VEGF表达被显著抑制;亚硒酸钠预处理后,p38MAPK磷酸化被明显抑制,同时VEGF表达显著降低.结论:p38MAPK调控VEGF的表达,表明p38MAPK和VEGF参与了糖尿病肾病的发生发展;亚硒酸钠可通过抑制p38信号通路而抑制VEGF的表达,从而有效地防治糖尿病肾病.     

p38 MAPK对冲击波促进T淋巴细胞增殖和分泌IL-2的作用

目的：研究有丝分裂原激活蛋白激酶p38（p38 MAPK）对冲击波促进激活的T淋巴细胞增殖及分泌IL-2的作用。方法：预先用p38 MAPK抑制剂( SB203580,20 μmol•L^-1)分别与人外周血单个核细胞（PBMC）和Jurkat T细胞共同培养,同时设立不含SB203580的阴性对照组,再用冲击波和PHA或抗-CD3/抗-CD28抗体的亚刺激量作用,检测T淋巴细胞增殖和分泌IL-2的变化。采用免疫印迹法,用抗- p38MAPK抗体及抗-磷酸化的p38MAPK(Thr180/Tyr182)抗体,测定冲击波作用后Jurkat T细胞上的p38 MAPK的表达及磷酸化。结果：与未用冲击波作用组比较,被PHA激活的PBMC细胞,在能量密度为(0.180±0.015) mJ•mm^-2的冲击波作用100、150、200、250、300、330和360次时,细胞对³H-TdR掺入量明显增高（P<0.01）。加入SB203580的PHA激活的PBMC细胞,在上述同样强度的冲击波作用时,细胞对³H-TdR掺入量低于没有加入SB203580对照组（P<0.01）。与未受冲击波作用组比较,被CD3和CD28激活的Jurkat T细胞,在上述同样强度的冲击波作用时,细胞上清液中的IL-2活性明显增高（P<0.01）。加入SB203580的CD3和CD28激活的Jurkat T细胞,在该强度的冲击波作用时,细胞上清液中的IL-2水平低于比未加入SB203580的对照组（P<0.01）。50～250次的(0.180±0.015)mJ•mm²的低能冲击波可使Jurkat T细胞的p38MAPK磷酸化, p38MAPK的磷酸化程度随着冲击波作用次数的增加而增加。结论：SB203580可抑制低能冲击波对激活的T淋巴细胞的增殖及分泌IL-2作用;低能冲击波通过激活T淋巴细胞内的p38 MAPK,促进激活的T淋巴细胞增殖及分泌IL-2。     

螺内酯对高糖培养大鼠肾小球系膜细胞P-p38MAPK和TGF-β1变化的影响

目的：研究糖尿病肾病（diabetic nephropath,DN）大鼠肾小球系膜细胞p38丝裂原活化蛋白激酶（MAPK）的表达及螺内酯对其的影响。方法：以高糖孵育大鼠肾小球系膜细胞（mesangial rell,MC）24h,用细胞免疫荧光法检测MC的磷酸化p38MAPK（P-p38MAPK）活性,并用ELISA检测转化生长因子-β1（TGF-β1）分泌状况。p38MAPK特异性抑制剂SB203580及不同浓度螺内酯预处理对其影响。结果：高糖激活p38MAPK,增加RMC的P-p38MAPK活性和TGF-β1的表达;SB203580显著抑制TGF-β1表达（P〈0.01）;螺内酯抑制P-p38MAPK的活化并减少TGF-β1的蛋白表达（P〈0.01）,并随浓度增高,抑制作用增强。结论：p38MAPK可能是糖尿病肾病发生的始动信号之一,螺内酯可能通过抑制p38MAPK磷酸化而减少TGF-β1分泌。     

调控高迁移组蛋白1诱导大鼠肺泡巨噬细胞表达诱生型一氧化氮合酶的信号通路

目的观察细胞外信号调节激酶(ERK)、p38分裂原激活的蛋白激酶(p38MAPK)及核因子-κB(NF-κB)在高迁移组蛋白1(HMGB1)诱导大鼠肺泡巨噬细胞表达诱生型一氧化氮合酶(iNOS)中的作用。方法体外培养的大鼠原代肺泡巨噬细胞(PRAMs)分别与ERK抑制剂PD98059、p38MAPK抑制剂SB203580和NF-κB抑制剂PDTC,以及PD98059联合SB203580共孵育2h后,培养基中分别加入重组人HMGB1作用6h。采用逆转录聚合酶链式反应检测培养细胞中iNOSmRNA表达,用Greiss法测定培养上清中NO2-/NO3-的含量。结果PD98059、SB203580和PDTC均可显著下调HMGB1诱导PRAMs表达iNOSmRNA和产生NO(P<0·05)。联合使用PD98059和SB203580可增强抑制iNOSmRNA表达和NO产生(P<0·05)。结论信号分子ERK、p38MAPK和NF-κB均参与了HMGB1诱导大鼠肺泡巨噬细胞表达iNOS和产生NO。     

Targeting of p38 Mitogen-activated Protein Kinases to Early Growth Response gene 1 （EGR-1） in the Human Paclitaxel-resistance Ovarian Carcinoma Cells

To investigate the relationship between the expression of early growth response gene 1 (EGR-1) and p38MAPK pathway in the paclitaxel resistance of ovarian carcinoma cells, the effect of p38MAPK inhibitor SB203580 on cell apoptosis was examined by using Hoechst 33258 staining. The intracellular Rh123 (Rhodamine 123) accumulation was detected by the flow cytometry (FCM). The 50% inhibition concentration (IC50) of paclitaxel for A2780/Taxol cells was determined by MTT method. Electrophoretic motility shift assay (EMSA) was employed to examine the EGR-1DNA binding activity. MDR1 and EGR-1 mRNA were assessed by RT-PCR. The expressed of p-gp, phos- phorylated p53 and p38 were detected by Western blotting. SB203580 could remarkably promote the apoptosis of A2780/Taxol cells, and the cell apoptosis was in a time-dependent manner. Cellular Rh123 accumulation was increased, and the IC50 of paclitaxel for A2780/Taxol cells was decreased significantly. A2780/Taxol cell line after SB203580 treatment was shown to have a significantly higher level of EGR-1 DNA binding activity. SB203580 down-regulated the activity of p38MAPK pathway, but up-regulated EGR-1 expression. SB203580 significantly increased the level of cellular phosphorylated p53 protein, but decreased the p-gp protein level and MDR1 mRNA level in A2780/Taxol cells. There existed a close relationship between p38MAPK pathway and the paclitaxel resistance of ovarian carcinoma cells. The expression of EGR-1 mediated by p38MAPK pathway plays a critical role in paclitaxel resistance of ovarian carcinoma cells.     

LXA4通过p38MAPK/Nrf2信号通路诱导H9c2心肌细胞HO-1高表达

目的:探讨脂氧素A4(lipoxin A4,LXA4)诱导心肌细胞H9c2中血红素加氧酶(heme oxygenase,HO)-1表达可能涉及的信号转导通路?方法:分别用核因子E2相关因子2(nuclear factor-E2 related factor 2,Nrf2)的抑制剂ATRA?p38MAPK的抑制剂SB203580?LXA4联合ATRA?LXA4联合SB03580预处理H9c2细胞后进行缺氧/复氧处理,RT-PCR?Western blot?免疫荧光等检测HO-1?Nrf2以及p38MAPK mRNA和蛋白表达的变化?结果:与只行缺氧/复氧处理的细胞相比,LXA4预处理的H9c2细胞HO-1 mRNA和蛋白的表达明显升高(P < 0.05),而ATRA?SB203580分别抑制了Nrf2的聚集和p38MAPK的磷酸化(P < 0.05),从而抑制了LXA4对HO-1的诱导(P < 0.05)?结论:LXA4预处理诱导心肌细胞H9c2的HO-1高表达,具有抗缺氧/复氧损伤的作用,其机制与p38MAPK/Nrf2信号通路有关?     

p38MAPK/eNOS信号通道在胰高血糖素样肽-1抑制AGEs诱导的人脐静脉内皮细胞凋亡中的作用

目的探讨p38MAPK信号通道在胰高血糖素样肽-1（GLP-1）拮抗糖基化终末产物（AGEs）诱导的人脐静脉内皮细胞凋亡
的作用。方法实验组分为对照组、AGEs组、GLP-1组、AGEs+GLP-1组、AGEs+抑制剂组及AGEs+GLP-1+抑制剂组,western
blot技术检测p-p38MAPK/p38MAPK、p-eNOS/eNOS蛋白表达情况,Annexin V/PI流式检测细胞凋亡率。结果与对照相比较,
单独加入AGEs或GLP-1可分别导致p-p38MAPK蛋白表达水平明显上升（P=0.001）或下降（P<0.001）;与对照组相比AGEs可
显著降低p-eNOS表达水平（P=0.007）,而予以GLP-1或p38MAPK抑制剂（SB203580）预处理后,受抑制的eNOS蛋白表达水平
再次显著升高（P=0.004）;在AGEs 组加入SB203580 或GLP-1 预处理后,AGEs诱导的细胞凋亡率均显著下降（P<0.001,P<
0.001）。结论GLP-1至少部分通过抑制p38MAPK蛋白磷酸化,上调磷酸化eNOS蛋白的表达,对人脐静脉内皮细胞起到抗凋
亡的保护作用。
     

The Relationship between p38MAPK and Apoptosis during Paclitaxei Resistance of Ovarian Cancer Cells

To investigate the relationship between p38 mitogen-activated protein kinase (p38MAPK) and cell apoptosis during the paclitaxel resistance of ovarian carcinoma cell lines, flow cytometry (FCM) and PI staining were employed to determine the effect of p38MAPK inhibitor SB203580 on the apoptosis of A2780/Taxol cells, a drug-resistant human ovarian carcinoma cell line. p38MAPK protein expression in SB203580-treated cells was immunochemically measured. The 50% inhibition concentration (IC(50)) of paclitaxel on A2780/Taxol cells was determined by MTT assay. MDR-1 mRNA, and expression of p38MAPK and phospho-p53 protein were detected by RT-PCR and Western blotting, respectively. The apoptosis rate of A2780/Taxol cells was (19.7+/-1.04)% 24 h after SB203580 treatment. A significant difference in apoptosis rate was found among experiment group, control group and untreated group (P<0.05). The relative reversal rate of A2780/Taxol cells to paclitaxel was (57.18+/-2.01)%. As compared with the control group and the untreated group, p38MAPK protein and MDR-1 mRNA in SB203580-treated cells was substantially decreased. The expression of p53 protein was significantly increased. It is concluded that p38MAPK pathway is related to paclitaxel resistance of ovarian carcinoma, and blockade of this pathway can promote the apoptosis of the drug-resistant cells and reverse the drug-resistance. Moreover, p38MAPK-mediated apoptosis in paclitaxel-resistant ovarian carcinoma cells depends on the activation of p53.     

脂多糖致急性肺损伤时Tribbles同源蛋白3表达变化

目的 探讨Tribbles同源蛋白3(TRB3)在脂多糖(LPS)致急性肺损伤(ALI)时的变化及其与p38-MAPK信号通路的关系.方法 体内实验:复制LPS致ALI大鼠模型,分5 ml/kg生理盐水组和5 ml/kg LPS刺激组,免疫组织化学法检测肺组织中TRB3蛋白表达,RT-PCR检测肺组织TRB3 mRNA表达.体外实验:体外培养大鼠肺微血管内皮细胞(PMVEC),随机分为LPS量效组(0、2、4、10 μg/ml LPS分别孵育4 h)、LPS时效组(10 μg/ml LPS分别孵育0、4、8、12 h)和p38抑制剂(SB203580)干预组(分为正常对照组、10 μg/ml LPS组、10 μmol/L SB203580组、10 μmol/L SB203580+10 μg/ml LPS组).Western blot法检测TRB3蛋白、p-p38和 p38-MAPK表达.结果 免疫组织化学法显示大鼠肺泡壁和腺上皮均表达TRB3;RT-PCR法检测大鼠肺组织和大鼠PMVEC均表达TRB3 mRNA;与生理盐水组比较,LPS致ALI大鼠肺组织TRB3 mRNA表达显著增加(t=15.524,P<0.01),LPS刺激的大鼠PMVEC中TRB3 mRNA表达增加(t=7.549,P<0.01);Western blot法显示PMVEC表达TRB3蛋白的表达量随LPS浓度(0、2、4、10 μg/ml)增加逐渐升高,差异有统计学意义(F=12.619,P<0.001);时效组TRB3蛋白表达量于4 h达高峰, 之后下降,8 h时仍高于0 h,差异有统计学意义(F=11.273,P<0.001).干预组:与正常对照组比较,10 μg/ml LPS组诱导大鼠PMVEC的p-p38、TRB3蛋白表达量增高(t=49.121、15.113,P<0.001);10 μmol/L SB203580+10 μg/ml LPS组与10 μg/ml LPS组比较,p-p38、TRB3蛋白表达量下降(t=7.040、11.900,P<0.05、0.001);10 μmol/L SB203580组对大鼠PMVEC表达p-p38及TRB3蛋白无影响,与正常对照组比较,差异无统计学意义.结论 LPS致ALI时TRB3表达增加,TRB3表达受p38-MAPK信号通路调控.     

p38MAPK信号通路对矽肺患者人胚肺成纤维细胞中TGF-β1表达的影响

目的探讨p38MAPK信号通路是否通过对SiO2活化的矽肺患者AM介导的人胚肺成纤维细胞（HELF）中TGF-β1表达的调控作用,进而参与肺纤维化的发生发展。方法以支气管肺泡灌洗法收集矽肺患者AM,在体外用含有SiO2（50μg/ml）的DMEM培养基和不含SiO2的DMEM培养基培养18h,然后收集培养的AM上清液。用组织贴块法获取培养HELF,与AM上清液共同孵育,用免疫细胞化学法检测HELF中TGF-β1的表达,Western blot法检测HELF中p-p38MAPK蛋白表达。结果经SiO2刺激的矽肺患者AM介导的HELF中TGF-β1和p-p38MAPK的表达与其他组相比增加,差异均有统计学意义（P〈0.05）。结论在本实验条件下,经SiO2刺激的矽肺患者AM培养上清可促进HELF表达TGF-β1和p-p38MAPK,10μmol/LSB203580可以抑制HELF表达TGF-β1和p-p38MAPK。     

The relationship between p38MAPK and apoptosis during paclitaxel resistance of ovarian cancer cells

Summary To investigate the relationship between p38 mitogen-activated protein kinase (p38MAPK) and cell apoptosis during the paclitaxel resistance of ovarian carcinoma cell lines, flow cytometry (FCM) and PI staining were employed to determine the effect of p38MAPK inhibitor SB203580 on the apoptosis of A2780/Taxol cells, a drug-resistant human ovarian carcinoma cell line. p38MAPK protein expression in SB203580-treated cells was immunochemically measured. The 50% inhibition concentration (IC₅₀) of paclitaxel on A2780/Taxol cells was determined by MTT assay. MDR-1 mRNA, and expression of p38MAPK and phospho-p53 protein were detected by RT-PCR and Western blotting, respectively. The apoptosis rate of A2780/Taxol cells was (19.7±1.04)% 24 h after SB203580 treatment. A significant difference in apoptosis rate was found among experiment group, control group and untreated group (P<0.05). The relative reversal rate of A2780/Taxol cells to paclitaxel was (57.18±2.01)%. As compared with the control group and the untreated group, p38MAPK protein and MDR-1 mRNA in SB203580-treated cells was substantially decreased. The expression of p53 protein was significantly increased. It is concluded that p38MAPK pathway is related to paclitaxel resistance of ovarian carcinoma, and blockade of this pathway can promote the apoptosis of the drug-resistant cells and reverse the drug-resistance. Moreover, p38MAPK-mediated apoptosis in paclitaxel-resistant ovarian carcinoma cells depends on the activation of p53. This project was supported by a grant from R&D program of Heilongjiang Province (No. GB05C402-11).     

高糖刺激人视网膜色素上皮细胞诱导型一氧化氮合酶表达及与p38 MAPK信号通路关系

目的:观察高糖刺激体外培养的人视网膜色素上皮(human retinal pigment epithelium,RPE)细胞表达诱导型一氧化氮合酶(inducible nitric oxide synthase,iNOS)的作用及其与p38信号通路(p38 mitogen activated protein kinase,p38 MAPK)的关系,从而进一步探讨糖尿病视网膜病变的发病机制.方法:培养人RPE细胞,分为对照组、高糖组、高糖 SB203580组和甘露醇组,采用四甲基氮唑蓝(MTT)比色法检测细胞活力,免疫荧光染色法观察RPE细胞中磷酸化p38 MAPK和iNOS的蛋白表达.结果:①MTT检测结果:高糖可以抑制RPE细胞增殖,加入特异性p38 MAPK抑制剂SB203580预处理后,抑制作用减弱;②免疫荧光法检测结果:与对照组相比,高糖组磷酸化p38 MAPK,iNOS蛋白表达明显增高;加入SB203580预处理后,iNOS表达被显著抑制.结论:高糖能够抑制RPE细胞增殖,通过活化p38 MAPK信号通路刺激RPE细胞iNOS的表达,在糖尿病视网膜病变的发生发展中起重要作用.