We have previously reported that the human ACAT1 gene produces a chimeric mRNA through the interchromosomal processing of two discontinuous RNAs transcribed from chromosomes 1 and 7. The chimeric mRNA uses AUG1397-139...We have previously reported that the human ACAT1 gene produces a chimeric mRNA through the interchromosomal processing of two discontinuous RNAs transcribed from chromosomes 1 and 7. The chimeric mRNA uses AUG1397-1399 and GGC1274-1276 as translation initiation codons to produce normal 50-kDa ACAT1 and a novel enzymatically active 56-kDa isoform, respectively, with the latter being authentically present in human cells, including human monocyte- derived macrophages. In this work, we report that RNA secondary structures located in the vicinity of the GGC1274-1276 codon are required for production of the 56-kDa isoform. The effects of the three predicted stem-loops （nt 1255-1268, 1286-1342 and 1355-1384） were tested individually by transfecting expression plasmids into cells that contained the wild-type, deleted or mutant stem-loop sequences linked to a partial ACAT1 AUG open reading frame （ORF） or to the ORFs of other genes. The expression patterns were monitored by western blot analyses. We found that the upstream stem-loop1255-1268 from chromosome 7 and downstream stem-loop1286-1342 from chromosome 1 were needed for production of the 56-kDa isoform, whereas the last stem-loop135s-1384 from chromosome 1 was dispensable. The results of experi- ments using both monocistronic and bicistronic vectors with a stable hairpin showed that translation initiation from the GGC1274-1276 codon was mediated by an internal ribosome entry site （IRES）. Further experiments revealed that translation initiation from the GGC1274-1276 codon requires the upstream AU-constituted RNA secondary structure and the downstream GC-rich structure. This mechanistic work provides further support for the biological significance of the chimeric nature of the human ACAT1 transcript.展开更多
目的:研究胰高血糖素样肽1(glucagon like peptide-1,GLP-1)能否通过影响CD36和酯酰辅酶A1(acyl-CoA1,ACAT1)的表达情况来减少巨噬细胞来源的泡沫细胞内胆固醇的含量。方法:从小鼠体内获取巨噬细胞,进行相应处理后分为4组:空白对照组、...目的:研究胰高血糖素样肽1(glucagon like peptide-1,GLP-1)能否通过影响CD36和酯酰辅酶A1(acyl-CoA1,ACAT1)的表达情况来减少巨噬细胞来源的泡沫细胞内胆固醇的含量。方法:从小鼠体内获取巨噬细胞,进行相应处理后分为4组:空白对照组、实验组、GLP-1激动组、GLP-1抑制组,并检测各组细胞内CD36、ACAT1 mRNA和蛋白的表达情况及总胆固醇(TC)、游离胆固醇(FC)及胆固醇酯(CE)的水平。结果:与空白对照组比较,实验组TC、FC、CE的含量及CD36、ACAT1 mRNA和蛋白表达明显提高(P<0.05);与实验组比较,GLP-1激动组TC、FC、CE的含量及CD36、ACAT1 mRNA和蛋白表达明显降低(P<0.05);与GLP-1激动组比较,GLP-1抑制组TC、FC、CE的含量及CD36、ACAT1 mRNA和蛋白表达明显升高(P<0.05)。结论:CD36和ACAT1的表达水平能够被GLP-1所抑制,并且在GPL-1的间接影响下,细胞内胆固醇的水平也会有所下降,使得巨噬细胞向泡沫细胞转化这一过程受到抑制,从而减缓动脉粥样硬化的发生发展。展开更多
Objective:To investigate whether glucagon like peptide-1(GLP-1)can reduce the cholesterol in foam cells derived from macrophages by affecting the expression of CD36 and acyl-CoA1(ACAT1)The content.Methods:Macrophages ...Objective:To investigate whether glucagon like peptide-1(GLP-1)can reduce the cholesterol in foam cells derived from macrophages by affecting the expression of CD36 and acyl-CoA1(ACAT1)The content.Methods:Macrophages were obtained from mice,and after corresponding treatment,they were divided into 4 groups:blank control group,experimental group,GLP-1 agitation group,GLP-1 inhibition group,and the expression of CD36,ACAT1 mRNA and protein in cells of each group was detected.Expression and levels of total cholesterol(TC),free cholesterol(FC)and cholesterol ester(CE).Results:Compared with the blank control group,the content of TC,FC,CE and the expression of CD36,ACAT1 mRNA and protein in the experimental group were significantly increased(P<0.05);compared with the experimental group,the content and content of TC,FC,CE in the GLP-1 excited group The expressions of CD36 and ACAT1 mRNA and protein were significantly decreased(P<0.05);compared with the GLP-1 agitation group,the contents of TC,FC and CE and the expression of CD36,ACAT1 mRNA and protein were significantly increased in the GLP-1 inhibition group(P<0.05).Conclusion:The expression levels of CD36 and ACAT1 can be suppressed by GLP-1,and under the indirect influence of GPL-1,the level of intracellular cholesterol will also be reduced,so that the process of macrophages to foam cells is suppressed Thereby slowing down the development of atherosclerosis.展开更多
β-酮硫解酶缺乏症(β-ketothiolase deficiency,BKD),又称线粒体乙酰乙酰基辅酶A硫解酶(T2)缺乏症,是一种罕见的由乙酰辅酶A酰基转移酶-1(acetyl coenzyme A acetyltransferase-1,ACAT1)基因变异引起的常染色体隐性遗传代谢性疾病。AC...β-酮硫解酶缺乏症(β-ketothiolase deficiency,BKD),又称线粒体乙酰乙酰基辅酶A硫解酶(T2)缺乏症,是一种罕见的由乙酰辅酶A酰基转移酶-1(acetyl coenzyme A acetyltransferase-1,ACAT1)基因变异引起的常染色体隐性遗传代谢性疾病。ACAT1基因编码在人类染色体11q22.3-23.1上,横跨基因组约27 kb的区域,包含12个外显子和11个内含子[1]。展开更多
目的探讨β-酮硫解酶缺陷病患JDN床表型特点及致病基因ACAT1突变类型。方法收集病例临床资料，分析患儿临床表现与生化代谢改变特点。提取1对同卵双胞胎先证者及其姐姐和父母的外周血基因组DNA，应用PCR扩增产物直接测序法对ACAT1基因...目的探讨β-酮硫解酶缺陷病患JDN床表型特点及致病基因ACAT1突变类型。方法收集病例临床资料，分析患儿临床表现与生化代谢改变特点。提取1对同卵双胞胎先证者及其姐姐和父母的外周血基因组DNA，应用PCR扩增产物直接测序法对ACAT1基因进行突变分析。结果先证者临床表现为无诱因的发热呕吐和严重的酮症酸中毒，血pH7．164，碳酸氢盐4．0mmol／L，尿酮＋＋＋＋。尿液气相色谱质谱分析显示先证者尿中β-羟基丁酸、2-甲基-3-羟基丁酸、甲基巴豆酰甘氨酸大量增高；血液串联质谱分析显示争羟基丁酰肉碱（C4-OH）、异戊酰肉碱（C5：1）、3-羟基异戊酰肉碱（C5-OH）含量明显增高。先证者父母临床表型正常，先证者胞姐也为患儿。DNA直接测序结果显示，2例先证者及姐姐的ACAn基因第7外显子存在c．622C〉T（p．R208x）和c．653C〉T（p．S218F）复合杂合突变；先证者母亲携带有ACAT1基因第7外显子c．622C〉T（p．R208X）杂合突变，父亲携带有ACAT1基因第7外显子c．653C〉T（p．S218F）杂合突变；在100名正常对照中未检测到该突变。经检索HGMD（The Human Gene Mutation Database）等数据库，c．653C〉T（p．S218F）突变为未报道过的新突变。结论β酮硫解酶缺陷病临床上以酮症酸中毒为主要表现，尿液气相色谱质谱分析和血液串联质谱分析对疾病的诊断有着重要提示作用，ACAT1基因突变分析是诊断本病的金标准。ACAT1基因第7外显子c．622C〉T（p．R208X）和c．653C〉T（p．S218F）复合杂合突变为该β-酮硫解酶缺陷病家系发病的分子遗传学基础。展开更多
文摘We have previously reported that the human ACAT1 gene produces a chimeric mRNA through the interchromosomal processing of two discontinuous RNAs transcribed from chromosomes 1 and 7. The chimeric mRNA uses AUG1397-1399 and GGC1274-1276 as translation initiation codons to produce normal 50-kDa ACAT1 and a novel enzymatically active 56-kDa isoform, respectively, with the latter being authentically present in human cells, including human monocyte- derived macrophages. In this work, we report that RNA secondary structures located in the vicinity of the GGC1274-1276 codon are required for production of the 56-kDa isoform. The effects of the three predicted stem-loops （nt 1255-1268, 1286-1342 and 1355-1384） were tested individually by transfecting expression plasmids into cells that contained the wild-type, deleted or mutant stem-loop sequences linked to a partial ACAT1 AUG open reading frame （ORF） or to the ORFs of other genes. The expression patterns were monitored by western blot analyses. We found that the upstream stem-loop1255-1268 from chromosome 7 and downstream stem-loop1286-1342 from chromosome 1 were needed for production of the 56-kDa isoform, whereas the last stem-loop135s-1384 from chromosome 1 was dispensable. The results of experi- ments using both monocistronic and bicistronic vectors with a stable hairpin showed that translation initiation from the GGC1274-1276 codon was mediated by an internal ribosome entry site （IRES）. Further experiments revealed that translation initiation from the GGC1274-1276 codon requires the upstream AU-constituted RNA secondary structure and the downstream GC-rich structure. This mechanistic work provides further support for the biological significance of the chimeric nature of the human ACAT1 transcript.
基金Key R&D Project of Shanxi Province(No.201903D421071)。
文摘Objective:To investigate whether glucagon like peptide-1(GLP-1)can reduce the cholesterol in foam cells derived from macrophages by affecting the expression of CD36 and acyl-CoA1(ACAT1)The content.Methods:Macrophages were obtained from mice,and after corresponding treatment,they were divided into 4 groups:blank control group,experimental group,GLP-1 agitation group,GLP-1 inhibition group,and the expression of CD36,ACAT1 mRNA and protein in cells of each group was detected.Expression and levels of total cholesterol(TC),free cholesterol(FC)and cholesterol ester(CE).Results:Compared with the blank control group,the content of TC,FC,CE and the expression of CD36,ACAT1 mRNA and protein in the experimental group were significantly increased(P<0.05);compared with the experimental group,the content and content of TC,FC,CE in the GLP-1 excited group The expressions of CD36 and ACAT1 mRNA and protein were significantly decreased(P<0.05);compared with the GLP-1 agitation group,the contents of TC,FC and CE and the expression of CD36,ACAT1 mRNA and protein were significantly increased in the GLP-1 inhibition group(P<0.05).Conclusion:The expression levels of CD36 and ACAT1 can be suppressed by GLP-1,and under the indirect influence of GPL-1,the level of intracellular cholesterol will also be reduced,so that the process of macrophages to foam cells is suppressed Thereby slowing down the development of atherosclerosis.
文摘目的探讨β-酮硫解酶缺陷病患JDN床表型特点及致病基因ACAT1突变类型。方法收集病例临床资料，分析患儿临床表现与生化代谢改变特点。提取1对同卵双胞胎先证者及其姐姐和父母的外周血基因组DNA，应用PCR扩增产物直接测序法对ACAT1基因进行突变分析。结果先证者临床表现为无诱因的发热呕吐和严重的酮症酸中毒，血pH7．164，碳酸氢盐4．0mmol／L，尿酮＋＋＋＋。尿液气相色谱质谱分析显示先证者尿中β-羟基丁酸、2-甲基-3-羟基丁酸、甲基巴豆酰甘氨酸大量增高；血液串联质谱分析显示争羟基丁酰肉碱（C4-OH）、异戊酰肉碱（C5：1）、3-羟基异戊酰肉碱（C5-OH）含量明显增高。先证者父母临床表型正常，先证者胞姐也为患儿。DNA直接测序结果显示，2例先证者及姐姐的ACAn基因第7外显子存在c．622C〉T（p．R208x）和c．653C〉T（p．S218F）复合杂合突变；先证者母亲携带有ACAT1基因第7外显子c．622C〉T（p．R208X）杂合突变，父亲携带有ACAT1基因第7外显子c．653C〉T（p．S218F）杂合突变；在100名正常对照中未检测到该突变。经检索HGMD（The Human Gene Mutation Database）等数据库，c．653C〉T（p．S218F）突变为未报道过的新突变。结论β酮硫解酶缺陷病临床上以酮症酸中毒为主要表现，尿液气相色谱质谱分析和血液串联质谱分析对疾病的诊断有着重要提示作用，ACAT1基因突变分析是诊断本病的金标准。ACAT1基因第7外显子c．622C〉T（p．R208X）和c．653C〉T（p．S218F）复合杂合突变为该β-酮硫解酶缺陷病家系发病的分子遗传学基础。
