牛磺酸下调单核-巨噬细胞ACAT-1表达

目的:观察牛磺酸对THP-1及THP-1源性巨噬细胞酰基辅酶A:胆固醇酰基转移酶1(ACAT-1)表达及活性的影响。方法:将THP-1细胞与PMA孵育48h使之分化为巨噬细胞,在有或无干扰素-γ(IFN-γ)的条件下,用不同浓度的牛磺酸与THP-1持续作用不同的时间,RTPCR检测ACAT-1mRNA水平,WesternBlot检测其蛋白表达,并测定其酶活性。结果:牛磺酸显著下调THP1及THP1源性巨噬细胞的ACAT1mRNA和蛋白表达水平以及ACAT-1活性(P<0.05～0.01,n=3);IFNγ促进ACAT1mRNA和蛋白表达、增强ACAT-1活性(P<0.05,n=3)的作用被牛磺酸部分抑制(P<0.05,n=3)。结论:牛磺酸不但能降低单核巨噬细胞ACAT-1的基础表达和活性,而且能抑制由IFN-γ诱导的ACAT-1表达和活性,这可能是其抗动脉粥样硬化的机制之一。     

胰岛素抵抗对巨噬细胞ACAT-1表达的影响及罗格列酮的干预作用

目的 进一步探讨动脉粥样硬化的发生机制及罗格列酮的干预作用.及过氧化物酶体增殖物激活受体-γ(PPAR-γ)高亲和性配体罗格列酮的干预作用.方法 体外培养人单核细胞系THP-1细胞,诱导分化为巨噬细胞,分别采用高浓度胰岛素、葡萄糖和不同浓度罗格列酮进行干预,实时定量PCR法检测巨噬细胞人巨噬细胞酰基辅酶A胆固醇酰基转移酶-1(ACAT-1)mRNA表达水平,Western blot检测其蛋白表达.结果 在高浓度胰岛素和葡萄糖状态下巨噬细胞ACAT-1m RNA和蛋白表达明显增加(P＜0.01);罗格列酮可明显下调其表达且呈浓度依赖性.结论 胰岛素抵抗状态下巨噬细胞ACAT-1表达水平升高,罗格列酮可明显下调其表达;此可能为其发挥抗动脉粥样硬化作用的机制之一.     

干扰素γ影响THP-1巨噬细胞脂质蓄积的机制

目的 探讨干扰素γ(IFN-γ)影响THP-1巨噬细胞脂质蓄积的机制.方法 THP-1巨噬细胞分组如下:A组(对照组)-2 g/L BSA的无血清培养基;B组-2 g/L BSA的无血清培养基+50 μg/L IFN-γ;C组-2 g/L BSA的无血清培养基+50 μg/L IFN-γ+25 mg/L oxLDL;D组-2 g/L BSA的无血清培养基+100 μg/L IFN-γ +25 mg/L oxLDL.处理24 h后,油红O染色和高效液相色谱观察细胞内脂质蓄积,FITC免疫荧光化学染色和PepTag(R)Assay法观察蛋白激酶C(PKC)α的亚细胞定位及细胞膜PKC活性,RT-PCR分析巨噬细胞清道夫受体CD36和胆固醇酰基转移酶-1(ACAT-1)的表达.结果 IFN-γ能显著诱导THP-1巨噬细胞内脂滴的聚集与融合;A、B、C、D四组每100个细胞油红O阳性细胞数分别为(8±1)、(21±3)、(35±2)、(69±6)个,胆固醇酯/总胆固醇比值(CE/TC)分别是22.5%、40.4%、49.6%、71.2%(超过50%,形成泡沫细胞),组间比较差异有显著性(P<0.05).随着IFN-γ的加入及浓度的加大,巨噬细胞内由FITC标记的荧光强度增大,而且强荧光明显由胞浆移向胞膜,巨噬细胞PKC活性显著增强.RT-PCR半定量分析显示IFN-γ干预可下调CD36 mRNA表达而上调ACAT-1 mRNA表达.结论 IFN-γ可能是通过PKC信号途径级联放大、ACAT-1表达上调,进而促进荷载与非荷载oxLDL巨噬细胞胆固醇的摄取、合成及酯化.     

葡萄糖对THP-1源性巨噬细胞酰基辅酶A:胆固醇酰基转移酶1表达的影响

研究葡萄糖对人THP-1单核分化巨噬细胞酰基辅酶A：胆固醇酰基转移酶1（ACAT-1）表达的影响。发现高糖作用下，巨噬细胞ACAT-1的mRNA及蛋白表达增加，这可能是糖尿病血管病变机制之一。     

酰基辅酶A胆固醇酰基转移酶-1与动脉粥样硬化

酰基辅酶A胆固醇酰基转移酶目前认为是细胞内唯一合成胆固醇酯的酶,维持着细胞以及生物体胆固醇代谢的平衡,而酰基辅酶A胆固醇酰基转移酶-1在动脉粥样硬化的发生、发展过程中发挥着至关重要的作用。自从酰基辅酶A胆固醇酰基转移酶的cDNA在1993年首次被克隆之后,许多学者对酰基辅酶A胆固醇酰基转移酶-1进行了大量的研究,现就近年来酰基辅酶A胆固醇酰基转移酶-1与动脉粥样硬化关系的研究予以综述。     

PPAR-γ对单核/巨噬细胞酰基辅酶A:胆固醇酰基转移酶-1表达效应的研究

目的　研究配体罗格列酮活化的过氧化体增殖物激活型受体 γ(PPAR γ)对单核 /巨噬细胞转分化过程中酰基辅酶A :胆固醇酰基转移酶 1 (Acyl CoA :cholesterolacyltransferases,ACAT 1 )表达效应的影响。 方法　在RPMI1 640培养基中培养人单核细胞 (THP 1 ) ,加入佛波酯(PMA)培养 48h,细胞贴壁呈巨噬细胞样分化。运用免疫细胞化学、逆转录聚合酶链反应、蛋白质免疫印迹等方法 ,观察单核巨噬细胞转分化前后PPAR γ对ACAT 1mRNA和蛋白表达水平的影响。结果　单核巨噬细胞转分化前后ACAT 1表达增加 ,罗格列酮活化的PPAR γ可明显抑制A CAT 1的表达。结论　动脉粥样硬化事件的发生可能与ACAT 1表达增强有关。罗格列酮活化的PPAR γ可能通过抑制ACAT 1表达 ,巨噬细胞摄取脂质降低 ,从而减少泡沫细胞的形成 ,发挥其抗动脉粥样硬化的作用     

血管紧张素Ⅱ对巨噬细胞和泡沫细胞ACAT-1及PPAR-γ表达的影响

目的:观察血管紧张素Ⅱ(Ang Ⅱ)对巨噬细胞和泡沫细胞过氧化体增殖物激活型受体γ(PPAR-γ)和酰基辅酶A:胆同醇酰基转移酶-1(ACAT-1)表达的影响.方法:将单核细胞株THP-I与160 nmol/L佛波酯(PMA)孵育48 h,使之分化为巨噬细胞,继以100 mg/L氧化型低密度脂蛋白(ox-LDL)诱导巨...     

PPAR-γ对巨噬细胞ACAT-1表达的影响及可能的信号途径

目的 探讨过氧化物酶体增殖物激活受体-γ(PPAR-γ)对巨噬细胞中酰基辅酶A:胆固醇酰基转移酶-1(ACAT-1)表达影响及可能参与的信号途径.方法 在RPMI1640培养基中培养人单核细胞(THP-1),加入佛波酯(PMA)培养48 h,细胞贴壁呈巨噬细胞样分化.在高浓度胰岛素状态下,分别加入PPAR-γ的配体罗格列酮和胰岛素信号途径阻滞剂[细胞外信号调节激酶(ERK)抑制剂PD98059、p38促分裂原活化蛋白激酶(p38MAPK)抑制剂SB203580和c-Jun氨基末端激酶(JNK)抑制剂SP600125],采用Western-blot法检测巨噬细胞ACAT-1蛋白水平,实时定量PCR法检测ACAT-1 mRNA水平.结果 在高胰岛素状态下,给予罗格列酮干预后ACAT-1 mRNA和蛋白表达均降低;再加入SB203580后ACAT-1 mRNA和蛋白表达较加入罗格列酮时均增加.结论 p38MAPK途径参与了PPAR-γ抑制ACAT-1的表达,并发挥抗动脉粥样硬化的作用.     

白介素-1对单核细胞向泡沫细胞分化过程中ACAT-1蛋白表达和活性的影响

目的探讨白介素-1（IL-1）对单核细胞向泡沫细胞分化过程中脂酰辅酶A-胆固醇酰基转移酶-1（ACAT-1）蛋白表达和活性的影响。方法200nmol／L佛波酯（PMA）诱导THP-1单核细胞48h使其转化为巨噬细胞,流式细胞术检测CDl4的表达;巨噬细胞与80mg／L氧化型低密度脂蛋白（Ox-LDL）共孵育24h,使之向泡沫细胞分化,油红O染色观察细胞质内脂质沉积;Westernblot检测各组细胞（单核细胞组、巨噬细胞组、泡沫细胞组、泡沫细胞＋IL-1组、泡沫细胞＋IL-1／Anti-ILl组）ACAT-l的蛋白表达,液相闪烁计数法检测ACAT-1的酶活性。结果单核细胞株THP-1与200nM的PMA共孵育48h后,分化为巨噬细胞,CDld阳性表达率为85．7％;巨噬细胞与Ox-LDL共孵育24h后,油红O染色胞浆内可见大量吞噬的脂质小滴。与单核细胞组相比,巨噬细胞组、泡沫细胞组和泡沫细胞＋IL-1组ACAT-1蛋白表达上调,活性升高（P〈0．05）,泡沫细胞＋IL-1／Anti-ILl组蛋白表达上调及活性升高不明显（P〉0．05）。结论IL-1对单核细胞向泡沫细胞分化过程中ACAT-1蛋白表达及酶活性有上调作用,IL-1单克隆抗体可以拮抗这种效应。     

胰岛素对单核/巨噬源性泡沫细胞ACAT-1表达的影响

研究胰岛素对单核/巨噬细胞转分化和泡沫细胞形成过程中酰基辅酶A:胆固醇酰基转移酶-1(ACAT-1)表达的影响,发现胰岛素对ACAT-1酶的活性、蛋白、mRNA表达均有增强作用。     

HO-1通过下调ACAT-1表达抑制小鼠平滑肌源性泡沫细胞形成的机制

目的 探讨血红素加氧酶(HO)-1在血管平滑肌细胞(VSMCs)泡沫样变过程中的作用及可能机制.方法 采用C57BL/6J背景野生型雄性小鼠主动脉来源VSMCs建立离体细胞模型.分别应用氧化型低密度脂蛋白(ox-LDL)、HO-1激动剂钴原卟啉(CoPPIX)和抑制剂锌卟啉(ZnPPIX)刺激模型细胞;油红O染色观察V...     

酰基辅酶A胆固醇酰基转移酶1基因过表达对泡沫细胞形成的影响

目的研究在三种不同细胞中过表达酰基辅酶A胆固醇酰基转移酶1基因对泡沫细胞形成的影响。方法构建携带酰基辅酶A胆固醇酰基转移酶1全长cDNA的pCDNA3.1质粒载体并稳定转染体外培养的人THP-1单核细胞、小鼠RAW264.7单核巨噬细胞和人胚肾293上皮细胞,以油红O染色法检测在乙酰化低密度脂蛋白作用下转染前后三种细胞形成泡沫细胞的情况。结果在相同的脂质负荷条件下,转染酰基辅酶A胆固醇酰基转移酶1基因的THP-1单核细胞和RAW264.7巨噬细胞同未转染的细胞相比泡沫细胞的形成数量增加,而人胚肾293上皮细胞无论是否转染酰基辅酶A胆固醇酰基转移酶1基因均不易形成泡沫细胞。结论单核巨噬细胞中过表达酰基辅酶A胆固醇酰基转移酶1基因可促进泡沫细胞的形成。     

细胞因子对平滑肌细胞及肌源性泡沫细胞内酰基辅酶A胆固醇酰基转移酶mRNA的影响

目的研究白细胞介素(IL)1β和肿瘤坏死因子α(TNFα)对酰基辅酶A胆固醇酰基转移酶(ACAT)mRNA水平的影响,探讨动脉粥样硬化形成的机制及其调节水平。方法在小鼠主动脉平滑肌细胞(VSMC)及肌源性泡沫细胞(FC)中分别加入IL1β和TNFα,孵育24h,用半定量RTPCR检测ACATmRNA表达。结果①无论有无细胞因子的干预,VSMC转变为FC后,ACATmRNA的表达均增加。②TNFα对VSMC和平滑肌源性FC中ACATmRNA的表达无影响。③IL1β能促使平滑肌源性FC中的ACATmRNA的表达。结论IL1β在转录水平上调ACATmRNA的表达,促使胆固醇的酯化和胆固醇的沉积,使VSMC向FC转化,参与动脉粥样硬化的形成和发展。     

雌激素对高糖诱导的HepG2细胞ACAT2表达的影响

目的 探讨雌激素对高糖诱导的酰基辅酶A:胆固醇酰基转移酶2(ACAT2)在HepG2细胞中表达的影响.方法 将培养好的HepG2细胞以0.7×106/L接种于六孔培养板内,加入无血清培养基继续培养24h,将细胞分为四组,对照组加入正常培养基,甘露醇组计入终浓度为25 mmol/L甘露醇溶液,高糖组加入的葡萄糖溶液培养基孵育12 h;雌激素组用含总浓度25 mmol/L葡萄糖的培养基与细胞孵育4h后,再加入终浓度为1×10-8 moL/L的17β-雌二醇孵育8h.RT-PCR和Western blot法检测各组ACAT2的表达水平.结果 高糖组HepG2细胞ACAT2的表达明显高于对照组和雌激素组(P＜0.001),雌激素组与对照组、甘露醇组比较无统计学意义.结论 雌激素可下调高糖诱导的ACAT2表达.     

肺炎衣原体通过上调酰基辅酶A:胆固醇酰基转移酶1诱导人单核细胞株THP-1源性泡沫细胞形成的实验研究

目的 观察酰基辅酶A:胆固醇酰基转移酶1(ACAT1)在肺炎衣原体(C.pn)诱导泡沫细胞形成中的作用,初步探讨C.pn诱导泡沫细胞形成的机制.方法 人单核细胞株(THP-1)给予160 mmol/L佛波酯(PMA)孵育48 h,诱导分化为巨噬细胞后随机分为4组:阴性对照组、阳性对照组、C.pn感染组和ACAT抑制剂58-035+C.pn感染组.分别运用RT-PCR和Western blot检测各组ACAT1 mRNA和蛋白表达.运用油红O染色观察细胞浆内脂滴的变化,用酶荧光学法检测细胞内胆固醇酯含量的变化.结果 C.pn感染呈浓度和时间依赖性地上调ACAT1 mRNA和蛋白表达.高浓度的C.pn(5×105和1×106IFU)感染THP-1源性巨噬细胞48 h后,细胞浆内脂滴明显增多,胆固醇酯与总胆固醇的比值明显增加(＞50%).ACAT抑制剂58-035可以抑制C.pn诱导的细胞浆内脂滴的增多.随着58-035浓度的增加,逐渐抑制C.pn诱导的细胞内胆固醇酯含量的增加.结论 ACAT1表达上调是C.pn诱导泡沫细胞形成的机制之一,这可能为进一步阐明C.pn感染促进动脉粥样硬化发生发展提供一个新的理论依据.     

肺炎衣原体通过上调酰基辅酶A:胆固醇酰基转移酶1诱导人单核细胞株THP-1源性泡沫细胞形成的实验研究

Objective To investigate the expression changes of acyl-coenzyme A: cholesterol acyhransferase 1 (ACAT1) on Chlamydia pneumoniae (C. pn) induced foam cell formation. Methods Human monocytic cell line (THP-1) was induced into macrophages by 160 nmol/L phorbol myristate acetate (PMA)for 48 h, and were randomly allocated into four groups: negative control group (50 μg/ml LDL for 48 h) ; positive control group (50 μg/ml ox-LDL for48 h) ; C. pn infection group (50 μg/ml LDL plus 1× 105,4×105,5×105and 1×106 IFU C.pn for 48 h or 1×106 IFU C.pn for 0,24,48 and 72h); ACAT inhibitor 58-035 plus C. pn infection group (1, 5, 10 μg/ml ACAT inhibitor 58-035 pretreatment for 1 h,50 μg/ml LDL and 1 × 106 IFU C. pn for 48 h). The mRNA and protein expressions of ACATI were determined by RT-PCR and Western blot, respectively. Lipid droplets in cytoplasm were observed by oil red 0 staining. The contents of intracellular cholesteryl esters were detected by enzyme-fluorescence. Results The mRNA and protein expressions of ACATI were significantly up-regulated in positive control cells compared those in negative control cells and further upregulated by C. pn infection in a time-dependent and concentration-dependent manner (all P ＜ 0.05). There were significantly increases in the accumulation of lipid droplets and the ratio of cholesteryl ester to total cholesterol in positive control cells as compared with negative control cells and these were further aggravated by C. pn (at the concentrations of 5× 105 and 1×106IFU for 48 h) and C. pn infection induced increases in the accumulation of lipid droplets and the ratio of cholesteryl ester to total cholesterol could he significantly attenuated by ACAT inhibitor 58-035 (all P ＜ 0.05). Conclusion Chlamydia pneumoniae induces THP-1-derived foam cell formation by up-regulating the expression of ACATI.     

肺炎衣原体通过上调酰基辅酶A:胆固醇酰基转移酶1诱导人单核细胞株THP-1源性泡沫细胞形成的实验研究

Objective To investigate the expression changes of acyl-coenzyme A: cholesterol acyhransferase 1 (ACAT1) on Chlamydia pneumoniae (C. pn) induced foam cell formation. Methods Human monocytic cell line (THP-1) was induced into macrophages by 160 nmol/L phorbol myristate acetate (PMA)for 48 h, and were randomly allocated into four groups: negative control group (50 μg/ml LDL for 48 h) ; positive control group (50 μg/ml ox-LDL for48 h) ; C. pn infection group (50 μg/ml LDL plus 1× 105,4×105,5×105and 1×106 IFU C.pn for 48 h or 1×106 IFU C.pn for 0,24,48 and 72h); ACAT inhibitor 58-035 plus C. pn infection group (1, 5, 10 μg/ml ACAT inhibitor 58-035 pretreatment for 1 h,50 μg/ml LDL and 1 × 106 IFU C. pn for 48 h). The mRNA and protein expressions of ACATI were determined by RT-PCR and Western blot, respectively. Lipid droplets in cytoplasm were observed by oil red 0 staining. The contents of intracellular cholesteryl esters were detected by enzyme-fluorescence. Results The mRNA and protein expressions of ACATI were significantly up-regulated in positive control cells compared those in negative control cells and further upregulated by C. pn infection in a time-dependent and concentration-dependent manner (all P ＜ 0.05). There were significantly increases in the accumulation of lipid droplets and the ratio of cholesteryl ester to total cholesterol in positive control cells as compared with negative control cells and these were further aggravated by C. pn (at the concentrations of 5× 105 and 1×106IFU for 48 h) and C. pn infection induced increases in the accumulation of lipid droplets and the ratio of cholesteryl ester to total cholesterol could he significantly attenuated by ACAT inhibitor 58-035 (all P ＜ 0.05). Conclusion Chlamydia pneumoniae induces THP-1-derived foam cell formation by up-regulating the expression of ACATI.     

肺炎衣原体通过上调酰基辅酶A:胆固醇酰基转移酶1诱导人单核细胞株THP-1源性泡沫细胞形成的实验研究

Objective To investigate the expression changes of acyl-coenzyme A: cholesterol acyhransferase 1 (ACAT1) on Chlamydia pneumoniae (C. pn) induced foam cell formation. Methods Human monocytic cell line (THP-1) was induced into macrophages by 160 nmol/L phorbol myristate acetate (PMA)for 48 h, and were randomly allocated into four groups: negative control group (50 μg/ml LDL for 48 h) ; positive control group (50 μg/ml ox-LDL for48 h) ; C. pn infection group (50 μg/ml LDL plus 1× 105,4×105,5×105and 1×106 IFU C.pn for 48 h or 1×106 IFU C.pn for 0,24,48 and 72h); ACAT inhibitor 58-035 plus C. pn infection group (1, 5, 10 μg/ml ACAT inhibitor 58-035 pretreatment for 1 h,50 μg/ml LDL and 1 × 106 IFU C. pn for 48 h). The mRNA and protein expressions of ACATI were determined by RT-PCR and Western blot, respectively. Lipid droplets in cytoplasm were observed by oil red 0 staining. The contents of intracellular cholesteryl esters were detected by enzyme-fluorescence. Results The mRNA and protein expressions of ACATI were significantly up-regulated in positive control cells compared those in negative control cells and further upregulated by C. pn infection in a time-dependent and concentration-dependent manner (all P ＜ 0.05). There were significantly increases in the accumulation of lipid droplets and the ratio of cholesteryl ester to total cholesterol in positive control cells as compared with negative control cells and these were further aggravated by C. pn (at the concentrations of 5× 105 and 1×106IFU for 48 h) and C. pn infection induced increases in the accumulation of lipid droplets and the ratio of cholesteryl ester to total cholesterol could he significantly attenuated by ACAT inhibitor 58-035 (all P ＜ 0.05). Conclusion Chlamydia pneumoniae induces THP-1-derived foam cell formation by up-regulating the expression of ACATI.     

肺炎衣原体通过上调酰基辅酶A:胆固醇酰基转移酶1诱导人单核细胞株THP-1源性泡沫细胞形成的实验研究

Objective To investigate the expression changes of acyl-coenzyme A: cholesterol acyhransferase 1 (ACAT1) on Chlamydia pneumoniae (C. pn) induced foam cell formation. Methods Human monocytic cell line (THP-1) was induced into macrophages by 160 nmol/L phorbol myristate acetate (PMA)for 48 h, and were randomly allocated into four groups: negative control group (50 μg/ml LDL for 48 h) ; positive control group (50 μg/ml ox-LDL for48 h) ; C. pn infection group (50 μg/ml LDL plus 1× 105,4×105,5×105and 1×106 IFU C.pn for 48 h or 1×106 IFU C.pn for 0,24,48 and 72h); ACAT inhibitor 58-035 plus C. pn infection group (1, 5, 10 μg/ml ACAT inhibitor 58-035 pretreatment for 1 h,50 μg/ml LDL and 1 × 106 IFU C. pn for 48 h). The mRNA and protein expressions of ACATI were determined by RT-PCR and Western blot, respectively. Lipid droplets in cytoplasm were observed by oil red 0 staining. The contents of intracellular cholesteryl esters were detected by enzyme-fluorescence. Results The mRNA and protein expressions of ACATI were significantly up-regulated in positive control cells compared those in negative control cells and further upregulated by C. pn infection in a time-dependent and concentration-dependent manner (all P ＜ 0.05). There were significantly increases in the accumulation of lipid droplets and the ratio of cholesteryl ester to total cholesterol in positive control cells as compared with negative control cells and these were further aggravated by C. pn (at the concentrations of 5× 105 and 1×106IFU for 48 h) and C. pn infection induced increases in the accumulation of lipid droplets and the ratio of cholesteryl ester to total cholesterol could he significantly attenuated by ACAT inhibitor 58-035 (all P ＜ 0.05). Conclusion Chlamydia pneumoniae induces THP-1-derived foam cell formation by up-regulating the expression of ACATI.