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。     

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。     

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。     

脂肪分化相关蛋白促进RAW 264.7细胞内酰基辅酶A:胆固醇酰基转移酶1高表达

目的 观察高表达脂肪分化相关蛋白细胞内酰基辅酶A∶胆固醇酰基转移酶1表达的变化,阐明脂肪分化相关蛋白促进细胞内脂质蓄积的机制.方法 构建的pQCXIP-HA-Adi逆转录病毒载体转染PA317包装细胞,获得pQCXIP-HA-Adi逆转录病毒.用病毒感染RAW 264.7细胞, Puromycin筛选后获得稳定高表达脂肪分化相关蛋白的RAW264.7细胞株.应用逆转录聚合酶链反应和免疫印迹法检测经感染后细胞内脂肪分化相关蛋白和酰基辅酶A∶胆固醇酰基转移酶1的表达.并应用阿托伐他汀处理高表达脂肪分化相关蛋白的RAW 264.7细胞,观察酰基辅酶A∶胆固醇酰基转移酶1表达的改变.结果 用pQCXIP-HA-Adi逆转录病毒感染RAW 264.7细胞后,脂肪分化相关蛋白和酰基辅酶A∶胆固醇酰基转移酶1 mRNA和蛋白表达明显升高,而对照组表达无明显变化.加入阿托伐他汀后,即在去除底物对酰基辅酶A∶胆固醇酰基转移酶1表达影响的情况下,高表达脂肪分化相关蛋白细胞内酰基辅酶A∶胆固醇酰基转移酶1表达仍升高.结论 高表达脂肪分化相关蛋白可明显上调RAW 264.7细胞酰基辅酶A∶胆固醇酰基转移酶1的表达.     

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.     

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.     

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.     

胆固醇诱导未折叠蛋白反应及其调节酰基辅酶A胆固醇酰基转移酶2基因的表达

目的探讨胆固醇对肝细胞和小肠粘膜上皮细胞中未折叠蛋白反应及其调节酰基辅酶A胆固醇酰基转移酶2基因表达的影响。方法以不同浓度(10mg/L和20mg/L)的游离胆固醇和氧化胆固醇温育肝癌细胞系HepG2细胞和小肠粘膜上皮细胞系Caco2细胞,应用半定量逆转录聚合酶链反应法检测两种细胞中X盒结合蛋白1和酰基辅酶A胆固醇酰基转移酶2mRNA的表达水平。结果随着游离胆固醇和氧化胆固醇温育浓度的升高,HepG2细胞和Caco2细胞中的X盒结合蛋白1和酰基辅酶A胆固醇酰基转移酶2mRNA表达均上调,呈现浓度依赖性。结论胆固醇和氧化胆固醇均可诱导未折叠蛋白反应中标记分子X盒结合蛋白1的表达,并上调酰基辅酶A胆固醇酰基转移酶2的表达,提示酰基辅酶A胆固醇酰基转移酶2的表达可能受未折叠蛋白反应的调控;鉴于酰基辅酶A胆固醇酰基转移酶2在胆固醇吸收的酯化过程中具有重要作用,未折叠蛋白反应可能在胆固醇吸收调控中具有重要意义。     

肿瘤坏死因子α对乙酰辅酶A:胆固醇酰基转移酶1基因表达的影响

目的研究泡沫细胞形成过程中肿瘤坏死因子-α（TNF-α）对乙酰辅酶A：胆固醇酰基转移酶1（ACAT1）基因的影响。方法体外培养人THP-1单核细胞系,由佛波酯作用使其分化为巨噬细胞,再由乙酰化低密度脂蛋白作用转变为泡沫细胞。TNF-α分别作用于上述三种细胞24h,用Western blot法检测ACAT1蛋白表达,RT-PCR法检测ACAT1 mRNA水平。结果在单核细胞分化为巨噬细胞及转变为泡沫细胞的过程中,ACAT1蛋白及mRNA均增加（P均〈0．05）;TNF-α可上调三种细胞ACAT1蛋白表达及mRNA水平（P均〈0．05）。结论单核细胞分化为巨噬细胞及转变为泡沫细胞的过程中,ACAT1基因表达明显增加,TNF-α可明显促进ACAT1基因表达。     

内脂素通过过氧化体增殖物激活型受体γ信号转导通路上调酰基辅酶A∶胆固醇酰基转移酶1的表达

目的观察过氧化体增殖物激活型受体γ信号转导通路在内脂素调控人THP-1单核细胞源性巨噬细胞酰基辅酶A∶胆固醇酰基转移酶1表达中的作用,探讨内脂素诱导泡沫细胞形成的机制和途径。方法 THP-1单核细胞诱导分化为巨噬细胞,随机分组,给予不同浓度的内脂素和过氧化体增殖物激活型受体γ激动剂罗格列酮进行干预,分别运用油红O染色法观察细胞内脂滴形成情况,逆转录聚合酶链反应法和免疫印迹法检测细胞过氧化体增殖物激活型受体γ和酰基辅酶A∶胆固醇酰基转移酶1mRNA和蛋白的表达,酶荧光学法检测细胞内总胆固醇和游离胆固醇含量,总胆固醇与游离胆固醇之差为胆固醇酯含量。结果与对照组比较,内脂素组细胞内脂滴形成增加,过氧化体增殖物激活型受体γmRNA和蛋白表达水平降低(P0.05),酰基辅酶A∶胆固醇酰基转移酶1mRNA和蛋白表达水平升高(P0.05),细胞内胆固醇酯含量升高(P0.05);随着内脂素浓度(10-7mol/L、10-6mol/L和10-5mol/L)升高,过氧化体增殖物激活型受体γmRNA和蛋白表达水平逐渐降低(r值分别为-0.73和-0.83,P0.05),酰基辅酶A∶胆固醇酰基转移酶1mRNA和蛋白表达水平逐渐升高(r值分别为0.91和0.72,P0.05)。与内脂素组比较,罗格列酮组酰基辅酶A∶胆固醇酰基转移酶1mRNA和蛋白表达水平降低(P0.05),细胞内胆固醇酯含量降低(P0.05);随着罗格列酮浓度(10μmol/L、15μmol/L和20μmol/L)升高,酰基辅酶A∶胆固醇酰基转移酶1mRNA和蛋白表达水平逐渐降低(r值分别为-0.69和-0.84,P0.05)。结论内脂素呈浓度依赖性下调THP-1单核细胞源性巨噬细胞过氧化体增殖物激活型受体γ的表达,上调酰基辅酶A∶胆固醇酰基转移酶1的表达,而罗格列酮呈浓度依赖性抑制内脂素所诱导的上述效应。提示内脂素可能通过过氧化体增殖物激活型受体γ信号转导通路上调酰基辅酶A∶胆固醇酰基转移酶1表达,使细胞内胆固醇酯合成增加,从而诱导泡沫细胞形成。     

脂肪分化相关蛋白通过酰基辅酶A∶胆固醇酰基转移酶1促进巨噬细胞脂质蓄积

目的观察高表达脂肪分化相关蛋白对酰基辅酶A∶胆固醇酰基转移酶1表达及脂质蓄积的影响。方法构建表达载体pcDNA3.1-HA-脂肪分化相关蛋白,使用THP-1巨噬细胞,通过瞬时转染使之高表达脂肪分化相关蛋白,依次用氧化型低密度脂蛋白和(或)丙泮尼地处理。逆转录聚合酶链反应和Western blot检测酰基辅酶A∶胆固醇酰基转移酶1及脂肪分化相关蛋白的表达,油红O染色和高效液相色谱检测细胞内脂质的蓄积。结果随着氧化型低密度脂蛋白浓度的增加,巨噬细胞脂肪分化相关蛋白及酰基辅酶A∶胆固醇酰基转移酶1表达明显增强,两者呈伴行关系。丙泮尼地能抑制酰基辅酶A∶胆固醇酰基转移酶1表达上调,且随处理时间延长,其表达逐渐减少,并且能减少细胞内脂滴生成。与对照组相比,瞬时转染pcDNA3.1-HA-脂肪分化相关蛋白能使脂肪分化相关蛋白表达明显升高。高表达脂肪分化相关蛋白的巨噬细胞能使酰基辅酶A∶胆固醇酰基转移酶1表达增加,促进细胞内胆固醇酯蓄积,并协同增强氧化型低密度脂蛋白的作用。加入丙泮尼地后,高表达脂肪分化相关蛋白的作用被减弱。结论高表达脂肪分化相关蛋白能上调THP-1巨噬细胞酰基辅酶A∶胆固醇酰基转移酶1表达,促进细胞内脂质蓄积。脂肪分化相关蛋白可能通过酰基辅酶A∶胆固醇酰基转移酶1促进细胞内胆固醇酯的蓄积。