In order to explore the effect and mechanisms of tumor necrosis factor-α （TNF-α） on the activity of the acyl coenzyme A： cholesteryl acyltransferase （ACAT）, THP-I monocytes were cul- tured and induced to differ...In order to explore the effect and mechanisms of tumor necrosis factor-α （TNF-α） on the activity of the acyl coenzyme A： cholesteryl acyltransferase （ACAT）, THP-I monocytes were cul- tured and induced to differentiate into macrophages with phorbol ester. TNF-α （60 ng/mL） was added at different time points into the macrophage-containing medium and the ACAT enzyme activity was measured by quantifying the incorporation of [1-^14C] oleoyl CoA into cholesteryl esters. The expression of ACAT-1 protein and mRNA was respectively detected by Western blotting and RT-PCR in THP-1 macrophages 24 h after treatment with TNF-α （60 ng/mL）. The results indicated that ACAT activity in THP-I macrophages treated with TNF-α was increased in a time-dependent manner. The expression levels of ACAT-1 protein and mRNA were significantly increased in THP-I macrophages after treatment with TNF-α （P〈0.05）. It was suggested that TNF-α could increase the activity of ACAT in THP-1 macrophages by up-regulating the expression of ACAT-1 gene.展开更多
ABSTRACT：Two separate studies tested the hypoth- esis that plasma low-density lipoprotein cholesterol LDL-C ） can be decreased by conjugated linoleic acid （CLA） by depressing hepatic acyl-coenzyme A： cholesterol...ABSTRACT：Two separate studies tested the hypoth- esis that plasma low-density lipoprotein cholesterol LDL-C ） can be decreased by conjugated linoleic acid （CLA） by depressing hepatic acyl-coenzyme A： cholesterol acyltransferase （ACAT） activity. In the first experiment, 3 groups of 6 early-weaned piglets were fed low-fat diets containing either 1.5% CLA, 1.5% corn oil or 1.5% beef tallow;fat provided 8% of the energy intake. In the second experiment, 4 groups of 6 early-weaned piglets were fed high-fat di- ets containing either 15% beef tallow, 12% beef tal- low plus 3% CLA, 15% corn oil, or 12% corn oil plus 3% CLA; fat provided 29% of energy intake. Cholesterol was balanced across diets in both experi-ments. In pigs fed the low-fat diets, all dietary fats in- creased LDL-C and triacylglycerols and decreased high-density lipoprotein cholesterol （ HDL-C ） and very low-density lipoprotein cholesterol （VLDL-C）. LDL-C was the same in pigs fed low-fat tallow or low-fat CLA diets. However, ACAT activity was near- ly 80% higher in pigs fed the low-fat tallow diet than in pigs fed the low-fat CLA diets. All high-fat diets increased LDL-C, HDL-C and triacylglycerols equally with no effect on VLDL-C. There were no unique fat- ty acid effects of the high-fat diets on ACAT activity. We conclude that supplemental fats had differential effects on hepatic ACAT activity and LDL-C, but on- ly in pigs fed low-fat diets.展开更多
目的:利用小干扰RNA(si RNA)技术干扰酰基辅酶A-胆固醇酰基转移酶1(ACAT1)基因在人结肠癌HT29细胞中的表达,观察ACAT1基因表达下降对于人结肠癌HT29细胞增殖和侵袭迁移能力的影响,了解ACAT1在结肠癌发生发展中的作用。方法:通过脂质体Hi...目的:利用小干扰RNA(si RNA)技术干扰酰基辅酶A-胆固醇酰基转移酶1(ACAT1)基因在人结肠癌HT29细胞中的表达,观察ACAT1基因表达下降对于人结肠癌HT29细胞增殖和侵袭迁移能力的影响,了解ACAT1在结肠癌发生发展中的作用。方法:通过脂质体Hiper Fect将ACAT1 si RNA转染至人结肠癌HT29细胞中干扰ACAT1基因的表达,利用Real time PCR检测转染前后ACAT1基因表达的变化,利用ACAT1基因干扰前后的HT29细胞,采用CFSE染色法检测HT29细胞增殖能力的变化;Transwell小室法检测HT29细胞侵袭和迁移能力的变化。结果:ACAT1 si RNA转染HT29细胞后ACAT1 m RNA的表达明显下降,ACAT1 si RNA转染后的HT29细胞与转染前比较,增殖及侵袭转移的能力均受到明显抑制,差异有统计学意义(P<0.05)。结论:ACAT1基因干扰使HT29细胞的增殖减慢,侵袭迁移能力降低,为结肠癌治疗提供新的靶点。展开更多
基金This project was supported by a grant from the National Natural Sciences Foundation of China (No. 30170378)
文摘In order to explore the effect and mechanisms of tumor necrosis factor-α （TNF-α） on the activity of the acyl coenzyme A： cholesteryl acyltransferase （ACAT）, THP-I monocytes were cul- tured and induced to differentiate into macrophages with phorbol ester. TNF-α （60 ng/mL） was added at different time points into the macrophage-containing medium and the ACAT enzyme activity was measured by quantifying the incorporation of [1-^14C] oleoyl CoA into cholesteryl esters. The expression of ACAT-1 protein and mRNA was respectively detected by Western blotting and RT-PCR in THP-1 macrophages 24 h after treatment with TNF-α （60 ng/mL）. The results indicated that ACAT activity in THP-I macrophages treated with TNF-α was increased in a time-dependent manner. The expression levels of ACAT-1 protein and mRNA were significantly increased in THP-I macrophages after treatment with TNF-α （P〈0.05）. It was suggested that TNF-α could increase the activity of ACAT in THP-1 macrophages by up-regulating the expression of ACAT-1 gene.
基金Supported by USDA/CSREES Competitive Grant 98-35206-6286federal funds from the USDA,ARS under Cooperative Agreement no.58-6250-1-003
文摘ABSTRACT：Two separate studies tested the hypoth- esis that plasma low-density lipoprotein cholesterol LDL-C ） can be decreased by conjugated linoleic acid （CLA） by depressing hepatic acyl-coenzyme A： cholesterol acyltransferase （ACAT） activity. In the first experiment, 3 groups of 6 early-weaned piglets were fed low-fat diets containing either 1.5% CLA, 1.5% corn oil or 1.5% beef tallow;fat provided 8% of the energy intake. In the second experiment, 4 groups of 6 early-weaned piglets were fed high-fat di- ets containing either 15% beef tallow, 12% beef tal- low plus 3% CLA, 15% corn oil, or 12% corn oil plus 3% CLA; fat provided 29% of energy intake. Cholesterol was balanced across diets in both experi-ments. In pigs fed the low-fat diets, all dietary fats in- creased LDL-C and triacylglycerols and decreased high-density lipoprotein cholesterol （ HDL-C ） and very low-density lipoprotein cholesterol （VLDL-C）. LDL-C was the same in pigs fed low-fat tallow or low-fat CLA diets. However, ACAT activity was near- ly 80% higher in pigs fed the low-fat tallow diet than in pigs fed the low-fat CLA diets. All high-fat diets increased LDL-C, HDL-C and triacylglycerols equally with no effect on VLDL-C. There were no unique fat- ty acid effects of the high-fat diets on ACAT activity. We conclude that supplemental fats had differential effects on hepatic ACAT activity and LDL-C, but on- ly in pigs fed low-fat diets.
文摘目的:利用小干扰RNA(si RNA)技术干扰酰基辅酶A-胆固醇酰基转移酶1(ACAT1)基因在人结肠癌HT29细胞中的表达,观察ACAT1基因表达下降对于人结肠癌HT29细胞增殖和侵袭迁移能力的影响,了解ACAT1在结肠癌发生发展中的作用。方法:通过脂质体Hiper Fect将ACAT1 si RNA转染至人结肠癌HT29细胞中干扰ACAT1基因的表达,利用Real time PCR检测转染前后ACAT1基因表达的变化,利用ACAT1基因干扰前后的HT29细胞,采用CFSE染色法检测HT29细胞增殖能力的变化;Transwell小室法检测HT29细胞侵袭和迁移能力的变化。结果:ACAT1 si RNA转染HT29细胞后ACAT1 m RNA的表达明显下降,ACAT1 si RNA转染后的HT29细胞与转染前比较,增殖及侵袭转移的能力均受到明显抑制,差异有统计学意义(P<0.05)。结论:ACAT1基因干扰使HT29细胞的增殖减慢,侵袭迁移能力降低,为结肠癌治疗提供新的靶点。
