ACAT1低甲基化在儿童肾病综合征发病机制中的作用研究

Hypomethylation of ACAT1 gene in pathogenesis of nephrotic syndrome in children

目的探讨酰基辅酶A:胆固醇酰基转移酶1(ACAT1)基因在儿童原发性肾病综合征发病机制中的作用。方法选取2018年6月至2019年12月温州医科大学附属第二医院收治的原发性肾病综合征患儿16例,为肾病组;另选同时期在医院体检的健康儿童16例为对照组。提取两组儿童外周静脉血单个核细胞的DNA和总mRNA,采用亚硫酸氢盐测序法检测ACAT1基因启动子甲基化水平,采用q PCR法检测ACAT1及DNA甲基转移酶Dnmt1、Dnmt3a、Dnmt3b的mRNA表达水平,采用Pearson相关分析ACAT1基因与胆固醇水平的关系。结果肾病组患儿ACAT1 mRNA表达水平高于对照组[(0.14±0.02)比(0.07±0.01),P<0.05],ACAT1基因启动子的甲基化水平低于对照组[(2.36±0.58)比(4.76±0.81),P<0.05],Dnmt1 mRNA表达水平低于对照组[(0.06±0.01)比(0.09±0.01),P<0.05],而两组Dnmt3a mRNA、Dnmt3b mRNA表达水平比较均无统计学差异(均P>0.05)。ACAT1甲基化水平与胆固醇水平呈负相关(r=-0.39,P<0.05),ACAT1 mRNA表达水平与胆固醇水平呈正相关(r=0.36,P<0.05)。结论肾病综合征患儿ACAT1基因启动子呈低甲基化状态,可能与Dnmt1 mRNA表达下调有关,从而使胆固醇代谢出现异常。

Objective To investigate the role of Acyl Co A:cholesterol Acyltransferase-1(ACAT1)gene methylation in the pathogenesis of nephrotic syndrome(NS).Methods Peripheral blood mononuclear cells(PBMCs)were collected from 16 children with NS and 16 healthy children in the Second Affiliated Hospital of Wenzhou Medical University from June 2018 to December 2019.DNA and total mRNA were extracted.DNA methylation of ACAT1 promoter was detected by bisulfite sequencing,and mRNA of ACAT1 and Dnmt1,Dnmt3 a,Dnmt3 b were detected by q PCR.Pearson correlation analysis was used to analyze the relationship between ACAT1 and cholesterol in children with nephrotic syndrome.Results The mRNA of ACAT1 was 0.14±0.02 in NS patients and 0.07±0.01 in controls(P<0.05).The methylation of ACAT1 promoter in 16 PNS patients and 16 controls was 2.36±0.58 and 4.76±0.81,respectively(P<0.05).The expression of Dnmt1 mRNA was in NS patients was lower than that in controls(0.06±0.01 vs 0.09±0.01,P<0.05),but there was no significant difference in the mRNA of Dnmt3 a and Dnmt3 b between two groups.The methylation of ACAT1 was negatively correlated with cholesterol level(r=-0.39,P<0.05)and expression of ACAT1 mRNA was positively correlated with cholesterol level(r=0.36,P<0.05).Conclusion The expression of ACAT1 mRNA is increased and ACAT1 gene is hypometholated in children with nephrotic syndrome,which may be related to the decreased expression of Dnmt1 mRNA leading to cholesterol metabolism disorder.