扇贝多肽对UVB照射HaCaT细胞后NO释放及热休克蛋白70表达的影响

目的观察UVB诱导的HaCaT细胞一氧化氮(nitricoxide,NO)释放及诱导型一氧化氮合酶(iNOS)表达的动态变化,探究扇贝多肽(polypeptide from Chlamys farreri,PCF)对UVB照射后NO释放、热休克蛋白70(heat shock protein70,HSP70)表达的影响。方法以电子自旋共振(electronspin resonance,ESR)技术检测NO的释放量;蛋白质印迹法检测iNOS、HSP70蛋白表达。结果 20 mJ.cm-2 UVB照射HaCaT细胞后NO释放明显增多,有3、24 h两个释放高峰期;PCF对各时间点NO的释放均有抑制作用;iNOS蛋白表达在UVB照射后6 h开始逐渐升高,18～24 h达到高峰;iN-OS抑制剂可抑制UVB照射后24 h时NO的释放,对3 h时NO的释放无影响;PCF可剂量依赖性增强UVB照射后HSP70的蛋白表达。结论 UVB照射HaCaT细胞诱导iNOS高表达从而引起NO产生增加,但在照射前期也可通过非iNOS途径生成NO;PCF可能通过增强UVB照射后HSP70的表达,进而抑制iNOS蛋白表达、减少NO的生成而保护HaCaT细胞免受UVB辐射损伤。     

知母皂苷通过调节NF-κB-iNOS-NO信号通路抑制LPS诱导的RAW264.7细胞功能

目的研究知母皂苷(SAaB)对脂多糖(LPS)诱导的RAW264.7细胞功能的影响,以及对NF-κB-诱导型一氧化氮合酶(iNOS)-NO信号通路的调节。方法以LPS刺激RAW264.7细胞构建体外炎症细胞模型,采用Griess法和ELISA法分别检测SAaB干预下,RAW264.7炎症细胞中的NO、iNOS、肿瘤坏死因子α(TNF-α)和白介素-6(IL-6)的含量;Western blot检测RAW264.7细胞NF-κB p65蛋白的表达水平。结果 RAW264.7细胞在LPS(10 mg·L~(-1))诱导下,NO、iNOS、TNF-α、IL-6的含量以及NF-κB p65蛋白表达水平与正常对照组比较均明显增高。SAaB(0.3、3、30 mg·L~(-1))可明显降低RAW264.7炎症细胞中NO、iNOS、TNF-α和IL-6的含量(P<0.01),且明显下调NF-κB p65的蛋白表达水平(P<0.01)。结论 SAaB可通过调节NF-κB-iNOS-NO信号通路,抑制LPS诱导的RAW264.7细胞功能。     

槐定碱对LPS诱导的RAW264.7巨噬细胞p38、iNOS表达的影响

目的探讨槐定碱(sophoridine,SRI)在内毒素导致的炎症反应中的作用。方法采用LPS诱导的RAW264.7巨噬细胞建立细胞炎症反应模型,实验细胞分为5组(n=6):空白对照组、LPS组、槐定碱组、SB203580组、SB203580+槐定碱组,利用反转录聚合酶链反应(RT-PCR)技术检测RAW264.7巨噬细胞p38 mRNA表达量;利用Western blot技术检测RAW264.7巨噬细胞p-p38与iNOS蛋白的表达量。结果槐定碱组与LPS组比较p-p38蛋白表达量和p38 mRNA表达量降低,但高于空白对照组(P<0.01),表明槐定碱可以抑制LPS诱导的RAW264.7巨噬细胞p-p38蛋白表达和p38 mRNA表达量;与LPS组比较,槐定碱组iNOS蛋白表达量降低,但高于空白对照组(P<0.01),SB203580+槐定碱组iNOS蛋白表达量低于槐定碱组和SB203580组(P<0.01),表明槐定碱可以抑制LPS诱导的RAW264.7巨噬细胞P38MAPK信号通路下游iNOS蛋白表达,并且与SB203580有协同作用。结论槐定碱可以通过抑制p38MAPK位点而下调p-p38、iNOS蛋白表达而发挥抗炎作用。     

洛伐他汀对肾小球系膜细胞iNOS表达及氧自由基水平的影响

目的 观察洛伐他汀对脂多糖(LPS)刺激后大鼠肾小球系膜细胞诱导型一氧化氮合酶(iNOS)mRNA的表达及细胞培养上清液中羟自由基(·OH),丙二醛(MDA),总超氧化物歧化酶(tSOD)含量的影响.方法 采用逆转录-聚合酶链反应(RT-PCR)法检测LPS作用大鼠系膜细胞后,洛伐他汀在不同时间段对系膜细胞iNOS mRNA表达的影响及分别检测细胞培养上清液中的·OH、MDA、tSOD的含量.结果 系膜细胞在正常情况下iNOS mRNA无明显表达,LPS作用24h后能引起iNOS mRNA的显著表达,洛伐他汀可抑制LPS引起的系膜细胞iNOS mRNA的表达.LPS作用于大鼠系膜细胞后,可引起细胞培养上清液中·OH、MDA含量的增加及tSOD含量的减少;加入洛伐他汀后细胞培养上清液中·OH、MDA含量减少,tSOD含量没有明显的变化.结论 洛伐他汀能抑制LPS引起的系膜细胞iNOS mRNA表达的增加及下调LPS引起的细胞培养上清液中·OH、MDA含量的增加.     

青蒿乙素对脂多糖诱导小鼠单核巨噬细胞RAW264.7炎症反应的抑制及机制

目的 探讨青蒿乙素的抗炎活性及其作用机制.方法 采用细菌脂多糖(LPS)诱导小鼠单核巨噬细胞RAW264.7建立炎症反应模型,经青蒿乙素处理后,采用Griess试剂检测NO的含量;采用酶联免疫法(ELISA)检测促炎症因子的水平;采用Western Blot检测炎症相关蛋白及激酶的表达水平.结果 青蒿乙素能明显抑制RA...     

蛋白酶体抑制剂MG-132对心肌梗死大鼠早期心功能及热休克蛋白70、热休克蛋白70羧基端相互作用蛋白的影响

目的：研究蛋白酶体抑制剂MG-132对心肌梗死大鼠心脏结构、功能的影响及其分子机制。方法：建立大鼠心肌梗死模型,干预组静脉注射MG-132（0.75mg/kg）,对照组及假手术组注射生理盐水,观察各组大鼠心脏心肌结构、功能及心肌热休克蛋白70（Hsp70）、热休克蛋白70羧基端相互作用蛋白（CHIP）的变化。结果：与心梗对照组比较,MG-132干预组心肌坏死减少,左室舒张末压和血清脑钠肽水平减低（P〈0.01）,同时心肌组织Hsp70、CHIPmRNA和蛋白质表达水平显著升高（P〈0.05）。结论：蛋白酶体抑制剂MG-132能够减轻心肌梗死、改善心功能,其机制与上调Hsp70、CHIP水平有关。     

脑缺血缺氧后大鼠外周血淋巴细胞热休克蛋白70的表达

目的 研究大鼠缺氧缺血性脑损伤后海马区脑组织病理学损伤变化和外周血单个核细胞的热休克蛋白(HSP)70的表达.方法 建立大鼠脑缺氧缺血模型,苏木素-伊红(HE)染色,光镜下观察脑组织病理学损伤的变化,采用流式细胞术(FCM)检测外周血淋巴细胞HSP70.结果 在缺氧缺性脑损伤后, 外周血淋巴细胞的HSP70水平迅速升高,24 h达到高峰51.05±2.27,其后逐渐降低14.13±1.04至正常水平(P＜0.01),与脑组织病理损伤的时序变化相一致.结论 运用FCM检测外周血淋巴细胞HSP70水平可以作为反映缺氧缺血后脑损伤的辅助指标.     

谷氨酰胺对COPD外周血NF-κB及HSP70表达的影响

目的探讨谷氨酰胺(Gln)对慢性阻塞性肺疾病(COPD)患者外周血单个核细胞(PBMC)中核因子-κB(NF-κB)和热休克蛋白70(HSP70)表达的影响。方法选择30例COPD急性加重期(AECOPD)患者为研究对象,设为AECOPD组,将治疗10~20 d后处于稳定期的上述患者设为SCOPD组,分别以Gln干预,收集干预前后各组外周血PBMC,并以健康人为正常对照组。采用Real-time PCR法检测各组PBMC中NF-κB P65 mRNA和HSP70 mRNA的表达水平。结果 AECOPD和SCOPD组NF-κB P65、HSP70的表达高于正常对照组(P<0.05),且急性期增高更为显著;AECOPD组和SCOPD组中,用Gln干预的较未用Gln的PBMC中HSP70表达升高(P<0.05),而NF-κB P65表达下降(P<0.01)。结论 Gln可抑制COPD患者炎症因子NF-κB的活性,升高HSP70的表达。     

黄芩素调控热休克蛋白70表达对溃疡性结肠炎大鼠的影响

目的研究黄芩素调控热休克蛋白70(HSP70)表达对溃疡性结肠炎大鼠的影响。方法用三硝基苯磺酸(TNBS)法构建溃疡性结肠炎大鼠模型,将建模成功的大鼠随机分为模型组、实验组及对照组,各15只,另外选取10只大鼠为正常组。实验组建模后第2天灌胃50 mg·kg^-1黄芩素,对照组灌胃0.42 g·kg^-1美沙拉嗪缓释颗粒,正常组与模型组则灌胃等量生理盐水,每天1次,连续干预2周。每天记录各组大鼠体重变化,进行疾病活动指数(DAI)评分;以苏木精-伊红染色观察大鼠结肠组织病理学形态;以免疫组化、蛋白质印迹法及实时荧光定量聚合酶链式反应检测结肠黏膜组织HSP70表达。结果治疗后,正常组、模型组、实验组和对照组大鼠DAI评分分别为0,(3.15±0.21),(0.89±0.14),(0.75±0.12)分,结肠黏膜组织损伤评分(CMIS)分别为(0.14±0.03),(2.86±0.23),(1.59±0.11),(1.35±0.10)分,结肠黏膜组织HSP70蛋白相对表达量分别为0.93±0.16,0.43±0.11,0.86±0.12,0.75±0.11,HSP70 mRNA相对表达量分别为1.32±0.23,0.21±0.06,0.78±0.11,0.65±0.08,差异均有统计学意义(均P<0.05)。结论黄芩素可有效减轻溃疡性结肠炎大鼠炎性反应及结肠黏膜组织炎性病理损伤,其作用机制可能与有效上调结肠黏膜组织HSP70表达相关。     

加热对肿瘤细胞热休克蛋白70产生的影响及意义

目的探讨加热对肿瘤细胞热休克蛋白70产生的影响,为热疗治疗肿瘤提供理论依据。方法对体外培养的人肝癌细胞SMMC-7721进行加热,42℃,2h,用超声细胞破碎仪破碎已经加热的SMMC-7721细胞,高速离心,用SDS-PAGE和Western blot方法对上清中HSP70的表达进行鉴定。结果加热42℃,2h的肝癌细胞热休克蛋白70（heat shock protein 70,HSP70）有较高表达。结论经加热42℃,2h的肝癌细胞热休克蛋白70（HSP70）有较高表达,为热疗治疗肿瘤提供了实验数据。     

Chloroquine inhibits inducible nitric oxide synthase expression in murine peritoneal macrophages

Induction of inducible nitric oxide synthase in vivo or in vitro in response to stimuli is only temporary. However, chronic localized expression of inducible nitric oxide synthase in certain organs has been associated with the development of autoimmune diseases or chronic inflammatory diseases. Chloroquine is being used as an antiinflammatory drug, and its inhibitory effect on the synthesis of pro-inflammatory cytokines, such as tumour necrosis factor-alpha and interferon-gamma, has been reported. In this study, we examined whether chloroquine could inhibit nitric oxide synthesis in murine peritoneal macrophages stimulated with interferon-gamma and lipopolysaccharide. Although prolonged incubation of cells with high concentrations of chloroquine showed some cytotoxicity, the drug itself was not cytotoxic when macrophages were preincubated with chloroquine for 2 hr, washed and stimulated with interferon-gamma and lipopolysaccharide in the absence of chloroquine for another 48 hr. The nitric oxide production from stimulated macrophages was markedly reduced by chloroquine in a dose-dependent manner and induction of inducible nitric oxide synthase mRNA was also suppressed by chloroquine pretreatment. These results show that chloroquine inhibits the induction of inducible nitric oxide synthase from interferon-gamma and lipopolysaccharide-stimulated macrophages, thereby reducing nitric oxide synthesis.     

Role of protein kinase C in BSA-AGE-mediated inducible nitric oxide synthase expression in RAW 264.7 macrophages

In the present study, the roles of protein kinase C (PKC) in BSA-derived advanced glycosylation end products (BSA-AGEs)-induced nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression were investigated. Treatment of RAW 264.7 cells with BSA-AGEs caused dose- and time-dependent increases in NO release and iNOS expression in RAW 264.7 cells, whereas BSA alone had no effect on iNOS induction. The tyrosine kinase inhibitor (genistein), the phosphatidylinositol-specific phospholipase C inhibitor (U-73122), the phosphatidylcholine-specific phospholipase C inhibitor (D-609), and the PKC inhibitors (staurosporine, Ro 31-8220, and Go 6976) all inhibited BSA-AGE-induced NO release and iNOS expression in RAW 264.7 cells. Stimulation of RAW 264.7 cells with BSA-AGEs resulted in the formation of inositol monophosphate; the response was attenuated by U-73122 and genistein. BSA-AGEs stimulated PKC-alpha, -betaI, -delta, and -eta but not -zeta translocation from the cytosol to the membrane. However, incubation of RAW 264.7 cells with BSA-AGEs increased phosphorylation of PKC-zeta at threonine-410, which reflects activation of PKC-zeta, indicating the possible involvement of these PKC isoforms in AGE-mediated effects. Pretreatment of RAW 264.7 cells with U-73122, D-609, and genistein reduced the AGE-stimulated translocation of PKC-alpha, -betaI, -delta, and -eta and activation of PKC-zeta. Taken together, these data suggest that BSA-AGEs might activate PKC and subsequently induce iNOS expression and NO release.     

香菇多糖对巨噬细胞一氧化氮和一氧化氮合酶活性的影响

目的研究香菇多糖(LTN)诱导巨噬细胞的一氧化氮(NO)生成和一氧化氮合酶(iNOS)的活性,探讨LTN的免疫调节作用机理.方法采用Griess反应和荧光法测定不同剂量的LTN作用小鼠腹腔巨噬细胞后NO的生成量和iNOS活性.观察mRNA转录抑制剂、蛋白质合成抑制剂和iNOS抑制剂对巨噬细胞NO的生成和iNOS活性的影响.结果LTN能使小鼠腹腔巨噬细胞NO生成增加,iNOS活性增高,并呈作用剂量依赖关系.3种抑制剂均能抑制LTN诱导的小鼠腹腔巨噬细胞N0的生成和iNOS活性.结论LTN能刺激小鼠腹腔巨噬细胞提高iNOS活性和NO的生成.提示LTN的免疫调节作用机制可能与LTN刺激巨噬细胞NO生成有关.     

香菇多糖对巨噬细胞一氧化氮和一氧化氮合酶活性的影响

目的研究香菇多糖(LTN)诱导巨噬细胞的一氧化氮(NO)生成和一氧化氮合酶(iNOS)的活性,探讨LTN的免疫调节作用机理.方法采用Griess反应和荧光法测定不同剂量的LTN作用小鼠腹腔巨噬细胞后NO的生成量和iNOS活性.观察mRNA转录抑制剂、蛋白质合成抑制剂和iNOS抑制剂对巨噬细胞NO的生成和iNOS活性的影响.结果LTN能使小鼠腹腔巨噬细胞NO生成增加,iNOS活性增高,并呈作用剂量依赖关系.3种抑制剂均能抑制LTN诱导的小鼠腹腔巨噬细胞N0的生成和iNOS活性.结论LTN能刺激小鼠腹腔巨噬细胞提高iNOS活性和NO的生成.提示LTN的免疫调节作用机制可能与LTN刺激巨噬细胞NO生成有关.     

芦荟大黄素对LPS诱导的RAW264.7细胞NO生成及iNOS表达的影响

目的观察芦荟大黄素(aloe-emodin)对脂多糖(LPS)诱导的RAW264.7细胞一氧化氮(NO)生成及诱生型一氧化氮合酶(iNOS)mRNA表达的作用。方法采用LPS诱导的RAW264.7细胞株建立细胞炎症反应模型。采用Griess试剂法测定NO释放量;采用硝普钠释放NO法测定NO自由基含量的变化;采用反转录聚合酶链反应(RT-PCR)分析iNOS mRNA表达改变。结果芦荟大黄素在0.69～2.50mg·L-1剂量范围内可抑制LPS诱导的RAW264.7细胞NO的释放,并呈剂量和时间依赖关系;芦荟大黄素在0.63～5.00mg·L-1剂量范围内可下调LPS诱导的RAW264.7细胞iNOS mRNA含量;而此范围内芦荟大黄素无直接清除NO自由基作用,不影响iNOS活性。结论芦荟大黄素可明显降低LPS诱导的RAW264.7细胞NO释放,呈时间和剂量依赖关系,此作用并非通过捕捉NO或抑制iNOS活性来实现,而是通过抑制iNOS mRNA表达发挥作用的。     

Inhibition of lipopolysaccharide-induced inducible nitric oxide (iNOS) mRNA expression and nitric oxide production by higenamine in murine peritoneal macrophages

Nitric oxide synthesized by inducible nitric oxide synthase (iNOS) has been implicated as a mediator of inflammation in rheumatic and autoimmune diseases. The effects of higenamine, a tetrahydroisoquinoline compound, on induction of NOS by bacterial lipopolysaccharide (LPS) were examined in murine peritoneal macrophages. LPS-induced nitrite/nitrate production was markedly inhibited by higenamine which at 0.01 mM, decreased nitrite/nitrate levels by 48.7+/-4.4%. This was comparable to the inhibition of LPS-induced nitrite/nitrate production by tetrandrin (49.51+/-2.02%) at the same concentration. Northern and Western blot analysis of iNOS expression demonstrated that iNOS expression was significantly attenuated following co-incubation of peritoneal macrophages with LPS (10 microg/ml; 18 hrs) and higenamine (0.001, 0.01 mM; 18 hrs). These results suggest that higenamine can inhibit LPS-induced expression of iNOS mRNA in murine peritoneal macrophages. The clinical implications of these findings remain to be established.