吡咯列酮对雨蛙肽诱导急性胰腺炎氧化应激过程的作用

目的 探讨过氧化物酶体增殖物激活受体(PPAR)γ激动剂吡咯列酮在雨蛙肽诱导大鼠急性胰腺炎中对氧化应激产物的影响及保护作用.方法 30只雄性SD大鼠随机分为对照组、雨蛙肽+不同剂量吡咯列酮组、雨蛙肽组、雨蛙肽+吡咯列酮+GW9662组.每组6只.急性胰腺炎造模30 min后处死大鼠,光镜下观察胰腺组织病理学变化,测定各组大鼠胰腺组织质量与体重比,比色法检测胰腺组织髓过氧化物酶(MPO)活性、丙二醛(MDA)和一氧化氮合酶(NOS)及组织诱导型一氧化氮合酶(iNOS)含量.结果 与对照组比较,雨蛙肽组胰腺组织水肿严重胰腺净重/体重(0.0072比0.0042)],MPO活性、MDA、NOS及iNOS含量升高(P＜0.01).与雨蛙肽组比较,吡咯列酮20 mg/kg及40 mg/kg组胰腺损伤减轻,胰腺净重/体重、MPO活性、MDA和NOS及iNOS含量降低(P＜0.05);与吡咯列酮40 mg/kg组比较,PPARγ拮抗剂GW9662逆转了吡咯列酮的保护作用(P＜0.05).结论 在雨蛙肽诱导的大鼠急性胰腺炎发病中,胰腺腺泡细胞的氧化应激损伤起了重要的作用,PPARγ激动剂吡咯列酮预先干预,通过降低氧化应激过程,对雨蛙肽诱导的大鼠急性胰腺炎有一定的保护作用.     

罗格列酮抑制肝星状细胞活化的作用机制研究

目的 探讨罗格列酮对大鼠肝星状细胞生物学特性的影响是否是通过PPARγ起作用.方法 设立10 μmol/L罗格列酮组、GW9662加10 μmol/L罗格列酮组、对照组、GW9662组.采用RT-PCR方法检测PPARγ及Ⅰ型前胶原mRNA表达;用Western blot法检测PPARγ及Ⅰ型胶原蛋白表达;电泳迁移分析法(EMSA)检测PPARγ蛋白的结合活性;用免疫细胞化学方法测定α-平滑肌肌动蛋白(α-SMA)表达的变化.结果 10 μmol/L罗格列酮组PPARγ mRNA及蛋白表达显著高于其他各组(P<0.01),Ⅰ型前胶原mRNA及蛋白表达明显低于其他各组(P<0.01);10 μmol/L罗格列酮组PPARγ蛋白结合活性最强,α-SMA表达明显低于其他组(P<0.05).结论 罗格列酮对大鼠肝星状细胞的影响是通过PPARγ起作用的.     

比格列酮和15d-PGJ2抑制促炎细胞因子减轻自身免疫性心肌炎

目的探讨过氧化物酶体增殖因子活化受体γ(PPARγ)在急性心肌炎发病中的作用;PPARγ配体治疗能否减轻心肌炎及其可能的机制.方法 6周龄雄性Lewis大鼠24只诱导自身免疫性心肌炎,随机分为阳性对照、15d-PGJ2治疗组及比格列酮治疗组(各组8只),正常大鼠8只作为正常对照.观察PPARγ配体15 d-PGJ2注射(200 μ·kg-1·d-1)和比格列酮口服(10 mg·kg-1·d-1)治疗对心肌炎症程度的影响;免疫组化检测心肌PPARγ表达、免疫杂交检测IκBα、 IL-1β和TNFα蛋白表达;核酸酶保护法检测心肌组织促炎细胞因子mRNA表达、电泳迁移率变动分析检测NF-κB的DNA结合活性.结果①PPARγ在炎症心肌组织中表达增强,主要定位在炎性浸润细胞的核和核周围区;②15d-PGJ2和比格列酮治疗使心肌炎症得到减轻,心重/体重、炎症分级严重程度明显减轻;③PPARγ配体15d-PGJ2和比格列酮治疗明显降低心肌组织中多种炎性细胞因子mRNA表达,及降低心肌内上调的IL-1β和TNFα蛋白表达;④与正常对照组相比,心肌炎阳性对照组心肌NF-κB的DNA结合活性增加5.6倍,15d-PGJ2和比格列酮治疗降低增强的NF-κB结合活性.⑤心肌炎阳性对照组心肌细胞核内NF-κB抑制物IκB蛋白含量明显降低;与心肌炎组相比,15d-PGJ2和比格列酮治疗分别增加IκB蛋白含量2.2和2.1倍.提示PPARγ配体治疗升高核内IκB水平而抑制NF-κB的活化.结论 PPARγ配体治疗减轻自身免疫性心肌炎,其机制与诱导IκB表达、阻断NF-κB活化、抑制促炎细胞因子表达有关.Ζ     

罗格列酮对同型半胱氨酸硫内酯所致内皮细胞损伤的保护作用与PPARγ介导的抗氧化相关

目的探讨罗格列酮对同型半胱氨酸硫内酯(HTL)所致血管内皮细胞损伤的保护作用及其机制。方法在培养的人脐静脉内皮细胞(HUVEC),用HTL与HUVEC共孵,用罗格列酮、卡托普利、夹竹桃麻素、过氧化体增殖物激活型受体γ(PPARγ)拮抗剂GW9662、核因子κB(NF-κB)信号传导通路抑制剂吡咯二硫代氨基甲酸乙酯(PDTC)进行预干预,MTT比色法检测细胞活力,逆转录聚合酶链反应检测PPARγm RNA的表达,荧光探针DCFADA检测细胞内活性氧簇(ROS),免疫荧光检测法测定NF-κB P65,酶标法检测可溶性细胞间黏附分子1(s ICAM-1)。结果 HTL与HUVEC共孵育24 h,明显降低内皮细胞活力,增加细胞内ROS水平和NF-κB的活化,升高细胞培养液中s ICAM-1的浓度(P0.01)。罗格列酮(0.001、0.01、0.1 mmol/L)能浓度依赖性地拮抗HTL所致的内皮细胞活力降低,抑制细胞内ROS水平的增加和NF-κB的活化,降低细胞培养液中s ICAM-1的浓度,与单独HTL损伤组比较,差异有显著性(P0.05或P0.01)。上述保护作用可被选择性的PPARγ拮抗剂GW9662所拮抗。夹竹桃麻素、卡托普利、PDTC对HTL引起的上述指标改变也有明显改善作用。结论罗格列酮对HTL所致的HUVEC损伤有显著保护作用,其机制可能与PPARγ介导的氧化应激反应的抑制有关。     

罗格列酮在人结肠癌氟尿嘧啶化疗增敏作用中对细胞凋亡的影响

目的 探讨过氧化物酶体增殖因子活化受体γ(peroxisome proliferator-activated receptor gammar,PPARγ)配体罗格列酮对人结肠癌氟尿嘧啶化疗增敏作用中细胞凋亡的影响.方法 体外培养人结肠癌HT-29细胞,分别或联合应用不同浓度的罗格列酮、氟尿嘧啶(fluorouracil,5-Fu)处理HT-29细胞,PI染色流式细胞术(FCM)分析、吖啶橙/溴乙啶(AO/EB)荧光染色法观察细胞凋亡率.用Western印迹法检测HT-29细胞PPARγ、NF-κB、Bcl-2、Bax的表达.结果 (1)流式细胞术和AO/EB荧光双染色法结果显示:5-Fu能明显诱导HT-29细胞凋亡,呈剂量依赖性.3.0,6.0,12.0 μg/L处理HT-29细胞72 h,细胞凋亡率分别为13.91%,18.16%,23.14%,罗格列酮亦能诱导HT-29细胞凋亡,呈剂量依赖性.1.0,10.0,100.0 μmol/L罗格列酮处理HT-29细胞72 h后,细胞凋亡率分别为1.44%,2.34%,14.13%.无细胞毒浓度的罗格列酮能显著促进5-Fu诱导HT-29细胞凋亡.1.0 μmol/L罗格列酮与12.0 μg/L 5-Fu合用使HT-29细胞凋亡率高达48.41%.(2)Werstern印迹法结果显示HT-29细胞表达PPARγ,罗格列酮作用HT-29细胞后上调PPARγ和Bax蛋白的表达,下调NF-κB、Bcl-2蛋白的表达,且呈浓度依赖方式(P<0.05).结论 (1)无细胞毒浓度下(1.0 μmol/L)罗格列酮能促进5-Fu诱导HT-29细胞凋亡.(2)罗格列酮的化疗增敏作用中对细胞凋亡的影响可能与活化PPARγ,下调NF-κB、Bcl-2蛋白表达,上调Bax蛋白表达有关.     

吡格列酮对糖尿病大鼠肺组织TNF-α和NF-κB的影响

目的 探讨过氧化物酶体增殖物激活受体(PPAR)-γ激动剂吡格列酮对糖尿病大鼠肺部损害的保护作用及其机制.方法 腹腔注射链脲佐菌素(55 mg/kg)制成糖尿病动物模型.48只健康SD雄性大鼠随机分为4组:对照组、糖尿病组、高、低剂量吡格列酮治疗组.8 w后检测存活大鼠肺组织肿瘤坏死因子(TNF)-α水平,取右肺组织,观察病理改变,并检测核因子(NF)-κB活性表达的变化.结果 糖尿病组大鼠肺组织TNF-α的水平和NF-κB活性较对照组显著增高(P＜0.05).给予吡格列酮处理8 w后,肺组织TNF-α的水平和NF-κB活性明显降低(P＜0.05).结论 PPAR-γ激动剂吡格列酮可有效减轻糖尿病大鼠肺部损害,其机制可能与抑制NF-κB过度活化和TNF-α的水平有关.     

血管紧张素1-7对雨蛙素诱导的胰腺腺泡细胞Toll样受体4/核因子-κB通路的影响

目的探讨血管紧张素1-7[Ang(1-7)]对雨蛙素诱导的胰腺腺泡细胞AR42J中Toll样受体(TLR)4/核因子(NF)-κB通路的影响。方法 AR42J细胞随机分为4组:对照组、模型组(10 nmol/L雨蛙素刺激)、Ang(1-7)组(10-7mol/L、10-6mol/L、10-5mol/L Ang(1-7)+10 nmol/L雨蛙素)及Ang(1-7)受体抑制剂A779组(10-7mol/L、10-6mol/L、10-5mol/L A779+10 nmol/L雨蛙素)。对照组为正常生长的AR42J细胞,模型组用10 nmol/L的雨蛙素刺激AR42J分别于15 min、30 min、2 h、6 h、12 h及24 h收集细胞,Ang(1-7)组为不同浓度Ang(1-7)作用30 min后再用雨蛙素刺激12 h收集细胞,A779组为不同浓度A779作用30 min后再用雨蛙素刺激12 h收集细胞。免疫荧光技术检测TLR4及NF-κB在AR42J中的表达部位,Western Blot技术检测各组细胞中TLR4及NF-κB的蛋白表达水平。计量资料组间比较采用单因素方差分析,进一步两两比较采用LSD-t检验。结果 AR42J细胞中可见TLR4及NF-κB均于细胞胞浆中表达。与对照组相比,模型组TLR4随雨蛙素造模时间呈先增高后减少的动态变化:在造模后30 min、2 h及6 h显著升高,12 h显示降低,差异均有统计学意义(P值均0.05);NF-κB随雨蛙素造模时间呈现逐渐升高的动态变化:在造模后30 min、2 h、6 h、12 h及24 h显著升高,差异均有统计学意义(P值均0.05)。Ang(1-7)浓度为10-5mol/L时TLR4及NF-κB蛋白表达下降,与模型组比较差异均有统计学意义(0.570±0.046 vs 0.893±0.057,0.520±0.071 vs 0.750±0.057,P值均0.05)。A779浓度为10-5mol/L时TLR4及NF-κB蛋白表达升高,与模型组比较差异均有统计学意义(0.680±0.045 vs 0.563±0.088,0.617±0.071 vs 0.453±0.054,P值均0.05)。结论雨蛙素刺激的AR42J细胞中,Ang(1-7)能够下调TLR4,抑制NF-κB激活发挥作用。     

罗格列酮对高糖诱导大鼠血管平滑肌细胞炎症和增殖的影响

目的 探讨罗格列酮(RSG)对高浓度葡萄糖孵育下的血管平滑肌细胞(VSMCs)炎症和凋亡的影响及其可能的分子机制.方法 以不同浓度的葡萄糖和罗格列酮单独或联合孵育大鼠胸主动脉平滑肌细胞,ELISA方法检测培养基中单核细胞趋化蛋白-1(MCP-1)的水平;采用流式细胞术检测VSMCs细胞凋亡率及Bcl-xl、Bcl-2蛋白表达;Western印迹检测胞浆中VSMCs Bcl-xl蛋白表达及NF-κBp65和IκBα的表达.结果 高葡萄糖浓度(11.2、22.5 mmol/L)培养可明显增加上清中MCP-1的浓度,促进VSMCs增殖,抑制其凋亡,上调Bcl-xl、Bcl-2蛋白表达,同时使NF-κB p65表达增加,IκBα表达下降;30及100 μmol/L RSG以浓度依赖形式减少VSMCs对MCP-1的分泌,抑制高葡萄糖培养下(11.2、22.5 mmol/L)VSMCs Bcl-xl、Bcl-2表达,促进其凋亡;下调NF-κBp65表达,促进IκBα表达.RSG拮抗剂GW9662(10 μmol/L)预处理可部分拮抗RSG的作用.结论 RSG可能通过对NF-κB通路的调控,减少炎症因子MCP-1分泌,下调Bcl-xl、Bcl-2表达,从而抑制高糖葡萄糖培养下的VSMCs炎症反应并促进其凋亡,从而在2型糖尿病大血管病变的防治中发挥重要作用.     

异鼠李素对高糖高脂诱导胰岛β细胞损伤保护作用的研究

目的探讨异鼠李素(ISO)对高糖高脂诱导小鼠胰岛β细胞株MIN6细胞损伤的保护作用及机制。方法不同浓度ISO预处理MIN6细胞后高糖高脂培养48 h,CCK8法筛选ISO最佳干预浓度。细胞分为正常对照(Con)组(11. 1 mmol/L葡萄糖)、高糖高脂损伤模型(M)组(33. 3 mmol/L葡萄糖+0. 25 mmol/L棕榈酸)及ISO预处理(ISO+M)组(10μmol/L ISO+33. 3 mmol/L葡萄糖+0. 25 mmol/L棕榈酸)。流式细胞术测定各组细胞凋亡率;硝酸还原酶法检测一氧化氮(NO)含量;RT-PCR测定IL-1β、IL-6、肿瘤坏死因子α(TNF-α)mRNA表达;Western blot法检测磷酸化核因子κB(NF-κB)抑制蛋白(IκB)激酶β(p-IKKβ)、磷酸化NF-κB抑制蛋白α(p-IκBα)、诱导型一氧化氮合酶(iNOS)及NF-κB p65蛋白的表达。结果细胞凋亡及NO含量M组高于Con组,ISO+M组低于M组(P0. 01)。IL-1β、IL-6、TNF-αmRNA,p-IKKβ、p-IκB、iNOS蛋白与NF-κB p65蛋白表达M组高于Con组,ISO+M组低于M组(P0. 05)。结论 ISO可减轻高糖高脂诱导的胰岛β细胞损伤,可能与抑制IκB激酶(IKK)/IκB/NF-κB/iNOS通路活性有关。     

吡格列酮对高糖诱导的小鼠主动脉平滑肌细胞晚期糖基化终末产物受体表达的影响及机制

目的探讨吡格列酮(PIO)对高糖诱导的小鼠主动脉血管平滑肌细胞(VSMCs)晚期糖基化终末产物受体(RAGE)表达的影响及其作用机制。方法原代培养小鼠主动脉VSMCs分为5组:(1)5. 5 mmol/L葡萄糖(正常浓度葡萄糖组,NG);(2)25 mmol/L葡萄糖(高浓度葡萄糖组,HG);(3)25 mmol/L葡萄糖+10μmol/L PIO(HG+PIO);(4)25 mmol/L葡萄糖+10μmol/L PIO+10μmol/L GW9662 (HG+PIO+GW9662);(5) 25 mmol/L葡萄糖+10μmol/L GW9662 (HG+GW9662)。应用RT-PCR及Western blot检测VSMCs中RAGE及过氧化物酶体增殖物激活受体γ(PPAR-γ)的表达。结果高糖增加VSMCs中RAGE的mRNA(P=0. 001)和蛋白(P=0. 002)表达;PPAR-γ激动剂PIO可抑制高糖增加VSMCs中RAGE的mRNA(P=0. 014)和蛋白(P=0. 006)表达的作用;加用PPAR-γ抑制剂GW9662后可明显减弱PIO对RAGE的mRNA(P=0. 001)和蛋白(P=0. 004)表达的抑制作用。结论 PIO可通过激活PPAR-γ,抑制高糖诱导的小鼠主动脉平滑肌细胞RAGE的表达。     

Induction of apoptosis in human liver carcinoma HepG2 cell line by 5-allyl-7-gen-difluoromethylenechrysin

AIM： To investigate the effect of 5-allyl-7-gen-difluoromethylenechrysin （ADFMChR） on apoptosis of human liver carcinoma HepG2 cell line and the molecular mechanisms involved.METHODS： HepG2 cells and L-02 cells were cultured in vitro and the inhibitory effect of ADFMChR on their proliferation was measured by MTT assay. The apoptosis of HepG2 cells was determined by flow cytometry （FCM） using propidium iodide （PI） fluorescence staining. DNA ladder bands were observed by DNA agarose gel electrophoresis. The influence of ADFMChR on the proxisome proliferator-activated receptor γ （PPARγ）, NF-κB, Bcl-2 and Bax protein expression of HepG2 cells were analyzed by Western blotting.RESULTS： MTT assay showed that ADFMChR significantly inhibited proliferation of HepG2 cells in a dose- dependent manner, with little effect on growth of L-02 cells, and when ICs0 was measured as 8.45 μmol/L and 191.55 μmol/L respectively, the potency of ADFMChR to HepG2 cells, was found to be similar to 5-fluorouracil （5-FU, ICso was 9.27 μmol/L）. The selective index of ADFMChR cytotoxicity to HepG2 cells was 22.67 （191.55/8.45）, higher than 5-FU （SI was 7.05 （65.37/9.27）. FCM with PI staining demonstrated that the apoptosis rates of HepG2 cells treated with 3.0, 10.0 and 30.0 μmol/L ADFMChR for 48 h were 5.79%, 9.29% and 37.8%, respectively, and were significantly higher when treated with 30.0 μmol/L ADFMChR than when treated with 30.0 μmol/L ChR （16.0%） （P 〈 0.05） and were similar to those obtained with 30.0 μmol/L 5-FU（41.0%）. DNA agarose gel electrophoresis showed that treatment of HepG2 cells with 10.0 μmol/L ADFMChR for 48 h and 72 h resulted in typical DNA ladders which could be reversed by 10.00 pmol/1 GW9662, a blocker of PPARy. Western blotting analysis revealed that aEer 24 h of treatment with 3.0, 10.0, 30.0 μmol/L ADFMChR, PPARy and Bax protein expression in HepG2 cells increased but Bcl-2 and NF-κB expression decreased; however, pre-incubation with 10.0 μmol/L GW9662 could efficiently antagonize and weaken the regulatory effect of 3.0, 30.0 μmol/L ADFMChR on PPARy and NF-KB protein expression in HepG2 cells.CONCLUSION： ADFMChR induces apoptosis of HepG2 cell lines by activating PPARγ, inhibiting protein expression of Bcl-2 and NF-κB, and increasing Bax expression.     

阿托伐他汀对晚期糖基化终末产物诱导的人内皮细胞单核细胞趋化蛋白-1mRNA表达影响及其机制的实验研究

目的 观察阿托伐他汀对晚期糖基化终末产物(advanced glycation end products,AGE)诱导的人脐静脉内皮细胞表达单核细胞趋化蛋白-1(MCP-1)的影响,并探讨其作用机制.方法 实验分组:(1)空白对照组.(2)牛血清白蛋白(BSA)对照组.(3)AGE诱导组:不同作用浓度的AGE(10-4、10-3、10-2及10-1g/L)与细胞共同培养24 h.(4) AGE+阿托伐他汀组:用不同作用浓度的阿托伐他汀(0.1、1、10 μmol/L)分别与细胞培养1 h,而后加入10-1 g/L AGE[根据(3)实验结果选取最佳浓度]与细胞共孵育24 h.(5)PPAR-γ激动剂(15 d-PGJ2)组:15 d-PGJ2( 10 μmol/L)与细胞孵育1 h后加入10-1 g/L AGE再与细胞共孵育24 h.(6)PPAR-γ抑制剂(GW9662)组:GW9662(5000 g/L)与细胞孵育1 h后加入AGE(10-1 g/L)和阿托伐他汀(1 μmol/L)[根据(4)实验结果选取最佳浓度]再与细胞共孵育24 h.胶原酶消化法获取人脐静脉内皮细胞.逆转录聚合酶链反应法分析细胞MCP-1和过氧化物酶增殖物活化受体γ(PPAR-γ)基因的表达.蛋白免疫印迹法测定细胞核因子-κB(NF-κB )p65表达水平.结果 (1)AGE(10-4、10-3、10-2及10-1 g/L)呈浓度依赖性提高人脐静脉内皮细胞MCP-1 mRNA表达水平,分别是空白对照组的1.53倍、2.12倍、2.56倍及4.71倍;AGE浓度为10-4 g/L时,细胞MCP-1 mRNA表达明显高于空白对照组(0.26±0.02比0.17±0.04,P<0.01).(2)与AGE组比,阿托伐他汀(0.1、1、10 μmol/L)呈浓度依赖性抑制AGE诱导的人内皮细胞MCP-1 mRNA的表达;阿托伐他汀浓度为1 μmol/L时,细胞MCP-1 mRNA表达水平显著低于AGE(10-1g/L)组(0.63±0.11比1.03±0.07,P<0.01).(3)AGE(10-1 g/L)组人脐静脉内皮细胞PPAR-γ mRNA的表达水平显著低于空白对照组(0.22±0.08比0.69±0.09,P<0.01),磷酸化和非磷酸化NF-κB p65蛋白表达水平显著高于空白对照组(0.78±0.06比0.31±0.01和1.61±0.16 比0.59±0.14,P均<0.01).(4)阿托伐他汀(1、10 μmol/L)组人脐静脉内皮细胞PPAR-γ mRNA表达水平显著高于AGE(10-1 g/L)组(0.59±0.02和0.61±0.06比0.22±0.08,P均<0.01);阿托伐他汀(1 μmol/L)组磷酸化和非磷酸化NF-κB p65蛋白表达水平显著低于AGE(10-1g/L)组(0.40±0.03比0.78±0.06和0.65±0.12比1.61±0.16,P均<0.01).(5)PPAR-γ激动剂(15 d-PGJ2)组细胞磷酸化和非磷酸化NF-κB p65蛋白表达水平显著低于AGE(10-1g/L)组 (0.21±0.01比0.78±0.06和0.67±0.14比1.61±0.16,P均<0.01),MCP-1 mRNA表达水平显著低于AGE(10-1g/L)组(0.17±0.02比0.93±0.12,P<0.01).(6)PPAR-γ抑制剂(GW9662)组细胞磷酸化和非磷酸化NF-κB p65蛋白表达水平显著高于AGE(10-1g/L)+阿托伐他汀(1 μmol/L)组(0.53±0.02比0.40±0.03和1.38±0.18比0.65±0.12,P均<0.01),MCP-1 mRNA表达水平显著高于AGE(10-1g/L)+阿托伐他汀(1 μmol/L)组(0.62±0.05比0.30±0.07,P<0.01).结论 阿托伐他汀可通过提高AGE诱导的人脐静脉内皮细胞对PPAR-γ表达抑制细胞NF-κB信号途径,进而抑制AGE诱导的人脐静脉内皮细胞的炎性反应.

Abstract：

Objective To investigate the effects of atorvastatin on advanced glycation end products (AGE) induced monocyte chemoattractant protein-1(MCP-1) expression in human umbilical vein endothelial cells(HUVECs)and whether this effect could be linked to peroxisome proliferator-activated receptor-γ (PPAR-γ) and nuclear factor-κB(NF-κB).Methods Grouping: (1)Blank control group;(2)BSA group;(3)AGE group:cells were incubated with different concentrations of AGE(10-4,10-3, 10-2 and 10-1g/L)for 24 hours; (4)AGE+Atorvastatin group: cells were incubated with different concentrations of atorvastatin(0.1,1,10 μmol/L)for 1 hour,then incubated with AGE (10-1 g/L) for 24 hours; (5)PPAR-γ agonist(15 d-PGJ2)group: cells were incubated with 15 d-PGJ2(10 μmol/L)for 1 hour,then incubated with AGE (10-1g/L) for 24 hours;(6)PPAR-γ inhibitor(GW9662)group:cells were incubated with GW9662(5000 nmol/L)for 1 hour,then incubated with atorvastatin (1 μmol/L)and AGE (10-1g/L) for 24 hours. Collagenase was used to isolate the endothelial cell from human umbilical vein;RT-PCR was performed to examine the mRNA expression of MCP-1 and PPAR-γ;Western blot was performed to detect NF-κB p65 protein.Results (1) The expression of MCP-1 mRNA was increased in proportion with increasing concentrations of AGEs which could be blocked by atorvastatin in a dose-dependent manner. (2) AGE(10-1g/L)significantly downregulated the expression of PPAR-γ mRNA(0.22±0.08 vs. 0.69±0.09, P<0.01) while upregulated the expression of phospho-NF-κB p65 protein (0.78±0.06 vs. 0.31±0.01,P<0.01) and nonphospho-NF-κB p65 protein (1.61±0.16 vs. 0.59±0.14,P<0.01) comparaed with the control group which could be significantly attenuated by atorvastatin. (3) PPAR-γ agonist decreased the expression of phospho-NF-κB p65 protein (0.21±0.01 vs. 0.78±0.06, P<0.01),nonphospho-NF-κB p65 protein (0.67±0.14 vs. 1.61±0.16,P<0.01)and MCP-1 mRNA (0.17±0.02 vs. 0.93±0.12, P<0.01)compared with AGE(10-1g/L)group. (4) PPAR-γ inhibitor antagonized the effect of atorvastatin on the expression of phospho-NF-κB p65 protein, nonphospho-NF-κB p65 protein and MCP-1 mRNA stimulated by AGE in HUVECs(P<0.01).Conclusion The anti-inflammatory properties of atorvastatin in AGE stimulated HUVECs may partly be attributed to the effect on upregulation of PPAR-γ and downregulation of NF-κB signaling pathway.     

Ghrelin inhibits IKKβ/NF-κB activation and reduces pro-inflammatory cytokine production in pancreatic acinar AR42J cells treated with cerulein

Background: Previous studies have provided conflicting results regarding whether the serum ghrelin concentration can reflect the severity of acute pancreatitis(AP). The present study examined the correlation between the serum ghrelin concentration and AP severity in animal models and investigated whether altered ghrelin expression in pancreatic acinar cells influences IKK β/NF-κ B signaling and pro-inflammatory cytokine production. Methods: Mild or severe AP was induced in rats by intraperitoneal injection of cerulein or retrograde cholangiopancreatic duct injection of sodium taurocholate, respectively. After successful model induction, serum ghrelin, tumor necrosis factor-α(TNF-α), and interleukin-6(IL-6) concentrations were determined by enzyme-linked immunosorbent assay, and IKK β/NF-κ B activation was assessed by immunohistochemistry. Subsequently, stable overexpression or knockdown of ghrelin in AR42 J cells was achieved by lentiviral transfection. After transfected cells and control cells were treated with cerulein for 24 h, the TNF-αand IL-1 β levels in the supernatants were determined by enzyme-linked immunosorbent assay, and the expression levels of p-p65, IKK β, and p-IKK β were detected by Western blotting. Results: In rat AP models, AP severity was correlated with increased IKK β/NF-κ B activation, proinflammatory cytokine production, and ghrelin secretion. The levels of pro-inflammatory cytokines TNF-αand IL-1 β as well as IKK β/NF-κ B signaling activity were increased upon knockdown of ghrelin in the AP acinar cell model and decreased with ghrelin overexpression. Conclusions: Serum ghrelin is related to the severity of AP. Ghrelin may play a protective role in the pathogenesis of AP by inhibiting the pro-inflammatory cytokines and the activation of the IKK β/NF-κ B signaling pathway.     

罗格列酮对慢性阻塞性肺疾病患者过氧化物酶体增殖物激活受体-γ信号通路的影响

目的 探讨罗格列酮对COPD患者过氧化物酶体增殖物激活受体-γ(PPAR-γ)、核因子-κB及肿瘤坏死因子-α(TNF-α)的影响.方法 2010年4-11月,选择COPD急性加重期患者30例,其中男22例,女8例,年龄54～87岁,平均(72±9)岁;健康体检者(对照组)24例,其中男18例,女6例,年龄52 ～80岁,平均(69±10)岁.抽取受试者空腹肘静脉血10 ml,分离培养外周血单个核细胞(PBMCs).将30例COPD患者的PBMCs均分为3份,分别根据不同的药物干预分为非干预组、罗格列酮干预组(罗格列酮组)和罗格列酮联合GW9662干预组(联合干预组),对照组PBMCs不加任何药物干预.采用实时荧光定量PCR检测PBMCs中PPAR-γ和核因子-κB的mRNA表达,细胞免疫荧光法结合激光扫描共聚焦显微镜检测PPAR-γ和核因子-κB蛋白表达及核转位,酶联免疫吸附试验检测细胞培养上清液中TNF-α含量.多组间比较采用方差分析,组间两两比较采用LSD-t检验,相关性分析采用Pearson检验.结果 mRNA(2-ΔΔCt值)和蛋白表达(荧光强度值):非干预组PPAR-γ(0.52±0.10和55±11)低于对照组(1和85±9),核因子-κB(1.69±0.07和145±17)高于对照组(1和118±7);罗格列酮组PPAR-γ(4.47±0.11和204±12)高于非干预组,核因子-κB(0.33±0.04和59±14)低于非干预组;联合干预组PPAR-γ(2.25±0.31和142±23)低于罗格列酮组,高于非干预组,核因子-κB(0.64±0.02和90±10)高于罗格列酮组,低于非干预组;组间比较差异均有统计学意义(F值为29.21～567.42,均P＜0.01).TNF-α浓度(μg/L):非干预组(96.2±1.4)高于对照组(85.3±1.0),罗格列酮组(63.0±2.5)低于非干预组,联合干预组(83.3±1.9)高于罗格列酮组,低于非干预组,组间比较差异有统计学意义(F值为293.72,P＜0.01).非干预组PPAR-γ蛋白主要位于细胞质,核因子-kB蛋白主要位于细胞核;对照组PPAR-γ和核因子-κB蛋白在PBMCs细胞质和细胞核中均有表达;罗格列酮组PPAR-γ蛋白转位于细胞核,核因子-kB蛋白转位于细胞质;联合干预组PPAR-γ蛋白转回细胞质,核因子-κB蛋白部分转移至细胞核.相关分析结果表明,PPAR-γ蛋白表达与核因子-κB蛋白表达及TNF-α浓度均呈负相关(r值分别为-0.935和-0.924,均P＜0.01),核因子-κB蛋白表达与TNF-α的浓度呈正相关(r=0.846,P＜0.01).结论 COPD的炎症可能与PPAR-γ表达及活性不足有关,罗格列酮能通过上调PPAR-γ表达和活性抑制核因子-kB,进而抑制TNF-α分泌,在COPD炎症中起着重要作用.     

姜黄素通过过氧化物酶体增生物激活受体-γ在大鼠实验性结肠炎中发挥抗炎作用

背景：研究显示姜黄素可激活过氧化物酶体增生物激活受体（PPAR）-γ，抑制三硝基苯磺酸（TNBS）诱导的大鼠结肠炎症。目的：以姜黄素和PPAR-γ拮抗剂GW9662单独或联合干预结肠炎模型大鼠，探讨姜黄素在大鼠实验性结肠炎中的抗炎机制。方法：以直肠内注入TNBS／乙醇溶液制备大鼠结肠炎模型。模型大鼠分别腹腔注射二甲基亚砜（DMSO）、姜黄素、GW9662或GW9662＋姜黄素2周，评价各组大鼠的死亡率、结肠损伤评分、血清促炎因子白细胞介素（IL）-2和抗炎因子IL-10水平以及结肠组织PPAR-γ和核因子（NF）-κB的表达。结果：与模型对照组相比，姜黄素能明显降低大鼠死亡率、结肠黏膜大体、组织学损伤评分和血清IL-2水平，升高血清IL-10水平，结肠组织PPAR-γ表达增高，NF-κB表达减低（P〈0．05）；GW9662＋姜黄素组大鼠结肠炎症无明显改善。正常对照组、模型对照组和姜黄素组PPAR-γ与NF-κB的表达均呈负相关（P〈0．01）。结论：姜黄素可通过PPAR-γ途径负性调节NF-κB的表达，在TNBS诱导的大鼠结肠炎中发挥抗炎作用。     

过氧化体增殖物激活型受体γ对巨噬细胞脂质蓄积及CD36表达的影响

目的观察过氧化体增殖物激活型受体γ激动剂和拮抗剂对THP-1巨噬细胞胆固醇蓄积及CD36表达的影响。方法实验分对照组、氧化型低密度脂蛋白组、Ciglitazone处理组和GW9662处理组,后两组用50 mg/L氧化型低密度脂蛋白分别与过氧化体增殖物激活型受体γ激动剂Ciglitazone(10μmol/L)及拮抗剂GW9662(10μmol/L)共同孵育24 h,高效液相色谱分析法检测细胞总胆固醇蓄积情况,RT-PCR和Western blot分别检测THP-1巨噬细胞CD36 mRNA和蛋白的表达。结果与对照组(76.28±10.36 mg/g)相比,氧化型低密度脂蛋白(121.63±13.32 mg/g)能使细胞总胆固醇含量显著增加,而Ciglitazone能使氧化型低密度脂蛋白处理的细胞总胆固醇含量进一步增加(136.23±14.78 mg/g),GW9662能使氧化型低密度脂蛋白处理的细胞总胆固醇含量减少(98.52±11.45 mg/g)。过氧化体增殖物激活型受体γ拮抗剂GW9662使巨噬细胞CD36 mRNA和蛋白的表达下调及胆固醇蓄积减少,过氧化体增殖物激活型受体γ激动剂Ciglitazone使巨噬细胞CD36 mRNA和蛋白的表达上调及胆固醇蓄积增多。结论过氧化体增殖物激活型受体γ拮抗剂使THP-1巨噬细胞胆固醇蓄积减少及氧化型低密度脂蛋白诱导的CD36表达下调。     

Peroxisome proliferator-activated receptor activity is involved in the osteoblastic differentiation regulated by bone morphogenetic proteins and tumor necrosis factor-α

Recent studies have suggested possible adverse effects of thiazolidinediones on bone metabolism. However, the detailed mechanism by which the activity of PPAR affects bone formation has not been elucidated. Impaired osteoblastic function due to cytokines is critical for the progression of inflammatory bone diseases. In the present study, we investigated the cellular mechanism by which PPAR actions interact with osteoblast differentiation regulated by BMP and TNF-α using mouse myoblastic C2C12 cells. BMP-2 and -4 potently induced the expression of various bone differentiation markers including Runx2, osteocalcin, type-1 collagen and alkaline phosphatase (ALP) in C2C12 cells. When administered in combination with a PPARα agonist (fenofibric acid) but not with a PPARγ agonist (pioglitazone), BMP-4 enhanced osteoblast differentiation through the activity of PPARα. The osteoblastic changes induced by BMP-4 were readily suppressed by treatment with TNF-α. Interestingly, the activities of PPARα and PPARγ agonists reversed the suppression by TNF-α of osteoblast differentiation induced by BMP-4. Furthermore, TNF-α-induced phosphorylation of MAPKs, NFκB, IκB and Stat pathways was inhibited in the presence of PPARα and PPARγ agonists with reducing TNF-α receptor expression. In view of the finding that inhibition of SAPK/JNK, Stat and NFκB pathways reversed the TNF-α suppression of osteoblast differentiation, we conclude that these cascades are functionally involved in the actions of PPARs that antagonize TNF-α-induced suppression of osteoblast differentiation. It was further discovered that the PPARα agonist enhanced BMP-4-induced Smad1/5/8 signaling through downregulation of inhibitory Smad6/7 expression, whereas the PPARγ agonist impaired this activity by suppressing BMPRII expression. On the other hand, BMPs increased the expression levels of PPARα and PPARγ in the process of osteoblast differentiation. Thus, PPARα actions promote BMP-induced osteoblast differentiation, while both activities of PPARα and PPARγ suppress TNF-α actions. Collectively, our present data establishes that PPAR activities are functionally involved in modulating the interaction between the BMP system and TNF-α receptor signaling that is crucial for bone metabolism.     

Inhibition of IκB kinase by thalidomide increases hepatitis C virus RNA replication

Hepatic fibrosis is an integral element in the progression of chronic liver disease. Elevated hepatic interleukin (IL)-8 is an important contributor to fibrosis in patients chronically infected with the hepatitis C virus (HCV). Thalidomide has been used to reduce liver inflammation and fibrosis in HCV-infected patients, but its impact on HCV replication remains unclear. This study examined the effect of thalidomide on HCV replication in vitro. Results revealed that while thalidomide reduced IL-8 and nuclear factor kappa B (NF-κB) activity by 95% and 46% in Huh-7 cells, increasing concentrations of thalidomide correlated with a linear rise in HCV replication (17-fold at 200 μm). The NF-κB inhibitors, wedelolactone and NF-κB activation inhibitor-1, which mimic the actions of thalidomide by preventing phosphorylation and activation of IκB kinase (IKK) and hence block NF-κB activity, increased HCV RNA by 18- and 19-fold, respectively. During in vitro HCV replication in Huh-7 cells, we observed a 30% increase in IKKα protein and 55% decrease in NF-κB(p65)/RelA protein relative to cellular β-actin. Ectopic expression of IKKα to enhance the inactive form of IKK in cells undergoing virus replication led to a 13-fold increase in HCV RNA. Conversely, enhanced expression of NF-κB(p65)/RelA in infected cells resulted in a 17-fold reduction in HCV RNA. In conclusion, HCV RNA replication was significantly augmented by the inhibition of IKK activation and subsequent NF-κB signalling, whereas a restoration of NF-κB activity by the addition of NF-κB/RelA markedly reduced HCV replication. This study lends added importance to the role of the NF-κB signalling pathway in controlling HCV replication.