Inflammation, miRNA and autophagy in diabetes

糖尿病中的炎症、miRNA 和自噬

基本信息

批准号：
8711702
负责人：
Paras Kumar Mishra
金额：
$ 37.5万
依托单位：
UNIVERSITY OF NEBRASKA MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-01-07 至 2018-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8711702
关键词：
Ablation Address Antioxidants Attenuated Autophagocytosis Binding Sites Biological Assay Biological Markers Blood Breeding C3H/HeJ Mouse Cardiac Cardiac Myocytes Cardiomyopathies Cardiovascular Diseases Clinical Research Confocal Microscopy Diabetes Mellitus Dose Down-Regulation Endopeptidases Enhancers Fibrosis Functional disorder Gel Gelatin Zymography Gelatinase B Gene Targeting Genes Genetic Transcription Glucose Goals Heart Heart Hypertrophy Heart failure Hybrids Hydrogen Peroxide Hyperglycemia Impairment In Situ Inflammation Inhibition of Matrix Metalloproteinases Pathway Lead Luciferases Measures Mediating MicroRNAs Molecular Morbidity - disease rate Mus Muscle Fibers Myocardium Myosin ATPase Nuclear Oxidants Oxidative Stress Patients Plasmids Play Proteins Pump Regulation Reporter Reporter Genes Resistance Role Skeletal Muscle Streptozocin Subfamily lentivirinae Testing Transfection Untranslated Regions Up-Regulation Western Blotting attenuation diabetic diabetic cardiomyopathy glucose uptake improved mortality tempol therapeutic target

项目摘要

Project Summary: A major cause of diabetes is impairment of glucose uptake by skeletal muscle that causes pumping of extra glucose into blood leading to hyperglycemia. Clinical studies revealed that diabetes causes cardiomyopathy and the chances of heart failure increases if the patient has diabetes. One of the mechanisms of cardiac dysfunction associated with diabetes is oxidative stress that activates latent matrix metalloproteinase-9 (MMP9), which in turn induces fibrosis and contractile dysfunction. However, the specific mechanisms for how oxidative stress activates MMP9, which leads to contractile dysfunction, have not been investigated. Our preliminary studies on HL1 cardiomyocytes suggest that inhibition of miR-133 induces MMP9 and over expression of miR-133 inhibits MMP9. The luciferase reporter assay revealed that miR-133 targets MMP9. Interestingly, glucose mediated induction of MMP9 is abrogated by miR-133. In the heart of diabetic Akita mice, myosin enhancer factor 2c (Mef2c- an inducer of miR-133) is alleviated, miR-133 is down regulated and MMP9 is robust. These results lead us to hypothesize that oxidative stress inhibits Mef2c causing attenuation of miR-133 that induces MMP9 leading to contractile dysfunction in diabetes. To address the hypothesis, we formulated three specific aims: Aim#1: To determine whether the miR-133 directly or indirectly inhibits the activation of MMP9. Hypothesis: MiR-133 directly inhibits MMP9 by targeting its 3/ UTR. It also indirectly inhibits MMP9 by inducing miR-466 and abrogating miR-705. Aim# 2: To determine whether the oxidative stress inhibits Mef2c causing attenuation of miR-133 in diabetes. Hypothesis: The oxidative stress inhibits Mef2c that causes attenuation of miR-133 in diabetes. Aim # 3: To determine whether the over-expression of miR-133 or Mef2c will inhibit MMP9 that in turn improve glucose uptake in skeletal muscle and ameliorates contractile dysfunction in diabetes. Hypothesis: The over expression of miR-133 and Mef2c inhibits MMP9 that enhances glucose uptake by skeletal muscle and mitigates contractile dysfunction of cardiomyocytes in diabetes. Our proposal unravels a new mechanism of regulation of MMP9 by miR-133. It also provides a new concept that miRNA inhibits a gene not only by directly targeting it rather it also induces / inhibits other miRNAs that indirectly influences the target gene. At translational level, the proposal will provide concrete evidence that over expression of miR-133 or ablation of MMP9 can ameliorate diabetic cardiomyopathy.

项目摘要：糖尿病的主要原因是导致骨骼肌吸收葡萄糖的损害将多余的葡萄糖泵入血液中，导致高血糖。临床研究表明糖尿病会引起心肌病，如果患者患有患者，心力衰竭的机会增加糖尿病。与糖尿病相关的心脏功能障碍的机制之一是氧化激活潜在基质金属蛋白酶-9（MMP9）的应力，又诱导纤维化和收缩功能障碍。但是，氧化应激如何激活的特定机制尚未研究导致收缩功能障碍的MMP9。我们的初步 HL1心肌细胞的研究表明，抑制miR-133会诱导MMP9及以上 miR-133的表达抑制MMP9。荧光素酶报告基准测定法显示miR-133 目标MMP9。有趣的是，葡萄糖介导的MMP9诱导被miR-133废除。在糖尿病秋田小鼠的心脏，肌球蛋白增强因子2C（MEF2C- miR-133的诱导剂）是缓解的miR-133被调节，MMP9稳健。这些结果使我们假设氧化应激抑制了MEF2C，导致miR-133的衰减，从而诱导MMP9 导致糖尿病的收缩功能障碍。为了解决该假设，我们提出了三个具体目的：目标＃1：确定miR-133是直接还是间接抑制激活 MMP9。假设：miR-133通过靶向3/ utr直接抑制MMP9。它也间接抑制 MMP9通过诱导miR-466并废除miR-705。目标＃2：确定氧化应激是否抑制MEF2C导致衰减的MEF2C 糖尿病中的miR-133。假设：氧化应激抑制了MEF2C，从而导致糖尿病中miR-133的衰减。目标＃3：确定miR-133或MEF2C的过表达是否会抑制 MMP9反过来改善骨骼肌的葡萄糖吸收并改善收缩糖尿病功能障碍。假设：miR-133和MEF2C的过度表达抑制了MMP9，从而增强了葡萄糖骨骼肌和减轻糖尿病心肌细胞的收缩功能障碍的吸收。我们的提议揭示了miR-133对MMP9调节的新机制。也是如此提供了一个新概念，miRNA不仅可以直接靶向基因，还可以抑制基因诱导 /抑制间接影响靶基因的其他miRNA。在翻译层面，该提案将提供具体的证据，表明mir-133或消融的表达 MMP9可以改善糖尿病心肌病。