Regulation of plasma LDL and HDL by microRNA-541-3p

高LDL和低HDL水平是心血管疾病的危险因素。我们的长期目标是识别和 解释microRNA（miRs）调节血浆脂蛋白水平的机制。在这里，我们报告 一种新miR-541- 3 p的鉴定，其减少人类ApoB分泌并增加ApoA 1分泌 肝癌细胞此外，我们发现miR-541- 3 p调控锌指（Znf）转录因子（TF）， 锌指101（Znf 101）和蓖麻锌指蛋白1（Casz 1），从而调节ApoB的表达 和ApoA 1。在这些新发现的基础上，以下目标集中于阐明miR- 541- 3 p调节这些TF的表达，以及这些TF如何调节ApoB和ApoA 1的表达。 此外，我们计划建立这些TF在控制血浆脂蛋白和动脉粥样硬化中的作用。 目标1. miR-541- 3 p增强Znf 101和Casz 1 mRNA的转录后降解 通过与3 ′-非翻译区（UTR）序列相互作用。我们建议建立RNA-RNA miR-541- 3 p和Znf 101/Casz 1 mRNA之间的相互作用对于mRNA水平的调节是必要的 并显示miR-541- 3 p与3 ′-UTR中的靶序列相互作用，从而增强mRNA降解。 目标2.解释Znf 101和Casz 1在细胞中调节ApoB和ApoA 1表达的机制。 人类和小鼠肝细胞。我们计划阐明Znf 101和Casz 1如何调节APOB的转录 APOA 1基因我们提出Znf 101是APOB基因转录的增强子，而Casz 1是 一种APOA 1基因转录的阻遏物。此外，我们计划阐明这些小鼠直系同源物的作用， 转录因子在小鼠Apob和Apoa 1基因转录调控中的作用这些研究应该能揭示 miR-541- 3 p调控ApoB和ApoA 1的基础。 目标3.阐明Zfp 961（人Znf 101的小鼠直系同源物）和Casz 1在调节人Znf 101的表达中的作用。 血浆LDL、HDL和小鼠动脉粥样硬化。在这些体内研究中，我们将研究生理学 在早期目标中确定和表征的TF对ApoB和ApoA 1调节的作用。我们将 询问这些TF对ApoB和ApoA 1调节是否降低LDL水平，增加HDL水平， 并减少动脉粥样硬化。这些研究应该证明，ApoB和ApoB的转录调控， ApoA 1在小鼠中导致抗动脉粥样硬化特征。 这项提议是基于我们发现了一种新的miR-541- 3 p，它调节ApoB和ApoA 1的表达。 通过两个新发现的TF向相反的方向移动。在完成建议的研究后，我们预计： (1)阐明miR-541- 3 p如何调节各种TF;（2）解释这些TF的分子机制 转录因子调节APOB和APOA 1转录;（3）确定所鉴定的转录因子的生理重要性。 调节血浆脂蛋白和动脉粥样硬化的分子和机制。这些基因和 这些机制可能成为预防和治疗心血管疾病的新的治疗靶点。

High LDL and low HDL levels are risk factors for cardiovascular disease. Our long-term goal is to identify and explain mechanisms through which microRNAs (miRs) regulate plasma lipoprotein levels. Here, we report the identification of a novel miR-541-3p that decreases ApoB secretion and increases ApoA1 secretion in human hepatoma cells. Furthermore, we show that miR-541-3p regulates the zinc finger (Znf) transcription factors (TFs) zinc finger 101 (Znf101) and castor zinc finger protein 1 (Casz1), thereby modulating the expression of ApoB and ApoA1, respectively. On the basis of these novel findings, the following aims focus on elucidating how miR- 541-3p regulates the expression of these TFs, and how these TFs regulate ApoB and ApoA1 expression. Furthermore, we plan to establish the roles of these TFs in the control of plasma lipoproteins and atherosclerosis. Aim 1. Establish that miR-541-3p enhances post-transcriptional degradation of Znf101 and Casz1 mRNA by interacting with 3´-untranslated region (UTR) sequences. We propose to establish that RNA-RNA interactions between miR-541-3p and Znf101/Casz1 mRNAs are necessary for the regulation of mRNA levels and show that miR-541-3p interacts with target sequences in the 3´-UTR, thereby enhancing mRNA degradation. Aim 2. Explain the mechanism of regulation of ApoB and ApoA1 expression by Znf101 and Casz1 in human and mouse liver cells. We plan to elucidate how Znf101 and Casz1 regulate transcription of the APOB and APOA1 genes. We propose to show that Znf101 is an enhancer of APOB gene transcription, and Casz1 is a repressor of APOA1 gene transcription. Furthermore, we plan to clarify the roles of mouse orthologs of these TFs in the transcriptional regulation of mouse Apob and Apoa1 genes. These studies should reveal the molecular underpinnings of the regulation of ApoB and ApoA1 by miR-541-3p. Aim 3. Elucidate the roles of Zfp961 (mouse ortholog of human Znf101) and Casz1 in the regulation of plasma LDL, HDL, and atherosclerosis in mice. In these in vivo studies, we will investigate the physiological roles of ApoB and ApoA1 regulation by the TFs identified and characterized in the earlier aims. We will interrogate whether regulation of ApoB and ApoA1 by these TFs decreases LDL levels, increases HDL levels, and diminishes atherosclerosis. These studies should demonstrate that transcriptional regulation of ApoB and ApoA1 leads to an anti-atherogenic profile in mice. This proposal is based on our discovery of a novel miR-541-3p that regulates the expression of ApoB and ApoA1 in opposite directions through two newly identified TFs. After completion of the proposed studies, we expect to: (1) elucidate how miR-541-3p regulates various TFs; (2) explain the molecular mechanisms through which these TFs regulate APOB and APOA1 transcription; and (3) establish the physiological importance of the identified molecules and mechanisms in the regulation of plasma lipoproteins and atherosclerosis. These genes and mechanisms may serve as new therapeutic targets to prevent and treat cardiovascular disease.