Human MicroRNA-548p Decreases Hepatic Apolipoprotein B Secretion and Lipid Synthesis.
Human MicroRNA-548p Decreases Hepatic Apolipoprotein B Secretion and Lipid Synthesis.
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DOI：
10.1161/atvbaha.117.309247
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发表时间：
2017-05
期刊：
影响因子：
--
通讯作者：
Hussain MM
中科院分区：
文献类型：
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作者：
Zhou L;Hussain MM
MicroRNAs(MiRs)在脂类代谢中起着重要的调节作用。载脂蛋白B作为极低密度脂蛋白组装中唯一必需的支架蛋白，是治疗高脂血症和动脉粥样硬化的靶点。我们的目标是找出降低apoB表达的miRs。生物信息学分析表明，hsa-miR-548p可与apoB基因相互作用。将miR-548p或Control miR分别导入人和小鼠肝细胞，检测其对apoB分泌和mRNA表达水平的调节作用。用定点突变的方法确定miR-548P在人apoB3‘-非翻译区的作用位点。在miR-548P过表达细胞中检测脂肪酸氧化和脂质合成，以探讨其在脂质代谢中的作用。我们观察到miR-548P显著减少人肝癌细胞和原代肝细胞apoB的分泌。机制研究表明，miR-548P与人apoB mRNA的3‘-非翻译区相互作用，促进转录后降解。生物信息学计算表明miR-548P与人apoB基因有两个潜在的结合位点。定点突变研究表明miR-548P靶点I包括种子序列和补充序列。MIR-548P对人肝癌细胞的脂肪酸氧化没有影响，但通过减少HMGCR和参与胆固醇和脂肪酸合成的ACSL4酶而显著减少脂肪合成。总之，miR-548P通过减少人类肝细胞中不同基因的表达来减少脂蛋白的产生和脂质的合成。这些研究表明miR-548p通过靶向mRNA来调节apoB的分泌。这可能是有用的治疗动脉粥样硬化，高脂血症和肝骨病。
MicroRNAs (miRs) play important regulatory roles in lipid metabolism. ApoB, as the only essential scaffolding protein in the assembly of very low density lipoproteins, is a target to treat hyperlipidemia and atherosclerosis. We aimed to find out miRs that reduce apoB expression. Bioinformatics analyses predicted that hsa-miR-548p can interact with apoB mRNA. MiR-548p or Control miR was transfected in human and mouse liver cells to test its role in regulating apoB secretion and mRNA expression levels. Site-directed mutagenesis was used to identify the interacting site of miR-548p in human apoB 3′-untranslated region. Fatty acid oxidation and lipid syntheses were examined in miR-548p overexpressing cells to investigate its function in lipid metabolism. We observed that miR-548p significantly reduces apoB secretion from human hepatoma cells and primary hepatocytes. Mechanistic studies showed that miR-548p interacts with the 3′-untranslated region of human apoB mRNA to enhance posttranscriptional degradation. Bioinformatics algorithms suggested two potential binding sites of miR-548p on human apoB mRNA. Site-directed mutagenesis studies revealed that miR-548p targets site I involving both seed and supplementary sequences. MiR-548p had no effect on fatty acid oxidation but significantly decreased lipid synthesis in human hepatoma cells by reducing HMGCR and ACSL4 enzymes involved in cholesterol and fatty acid synthesis. In summary, miR-548p reduces lipoprotein production and lipid synthesis by reducing expression of different genes in human liver cells. These studies suggest that miR-548p regulates apoB secretion by targeting mRNA. It is likely that it could be useful in treating atherosclerosis, hyperlipidemia and hepatosteatosis.