Inflammation, miRNA and autophagy in diabetes

糖尿病中的炎症、miRNA 和自噬

• 批准号: 9109667
• 负责人: Paras Kumar Mishra
• 金额: $ 37.63万
• 依托单位: UNIVERSITY OF NEBRASKA MEDICAL CENTER
• 依托单位国家: 美国
• 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/9109667
• 关键词: 3' Untranslated Regions; Ablation; Address; Attenuated; Autophagocytosis; Biological Assay; Cardiac; Cardiac Myocytes; Cardiovascular system; Co-Immunoprecipitations; Collagen; Complications of Diabetes Mellitus; Confocal Microscopy; Devices; Diabetes Mellitus; Disease; Dose; Elastin; Enhancers; Enzyme-Linked Immunosorbent Assay; Fibrosis; Flow Cytometry; Gel; Gelatin Zymography; Gelatinase B; Genes; Genetic Transcription; Glucose; Goals; Health; Heart; Hypertrophy; Immunoblotting; Immunohistochemistry; In Vitro; Inflammation; Inhibition of Matrix Metalloproteinases Pathway; Injection of therapeutic agent; Insulin; Interleukin-10; Ions; Knock-out; Light; Luciferases; M-Mode Echocardiography; MMP9 gene; Measures; Mediating; MicroRNAs; Microtubules; Molecular; Mus; Myocardial; Myocardial dysfunction; Myosin ATPase; Optics; Plasma; Plasmids; Radio; Regulation; Reporter; Reporting; Reverse Transcriptase Polymerase Chain Reaction; Role; Staining method; Stains; TNF gene; Tail; Techniques; Telemetry; Testing; Therapeutic; Trichrome stain method; Veins; chromatin immunoprecipitation; coronary fibrosis; diabetic; diabetic cardiomyopathy; differential expression; glucose monitor; improved; pressure

DESCRIPTION (provided by applicant): Despite the gigantic stride made towards understanding of diabetic complications, the molecular mechanism is unclear. Differential expression of miRNA is associated with diabetes mellitus (DM). The long term goal of the project is to understand the regulation of miRNA in DM. Inflammation induces tumor necrosis factor alfa (TNFa) and matrix metalloproteinase-9 (Mmp9), and attenuates interleukin-10 (IL-10) and miR-223. Also, myosin enhancer factor -2c (Mef2C: an inducer of miR-133(anti-hypertrophy and anti-fibrosis)) is down regulated and microtubule-associated protein1 light chain3 (LC3), autophagy related gene3 (Atg3) and beclin-1 (markers of autophagy) are induced. We reported that Mmp9 impairs contractility of cardiomyocytes and increases fibrosis, whereas ablation of Mmp9 improves contractility and up regulates miR-133. However, the role of Mmp9 and miR-133 axis in autophagy and DM is unknown. Our preliminary studies show that TNFa is induced and IL-10 and miR-223 are attenuated in diabetic hearts. Interestingly, TNFa is robust in hypertrophic cardiomyocytes. To investigate the mechanism of Mmp9 mediated regulation of miR-133 and autophagy in diabetes, we created double knock out (DKO) by deleting Mmp9 gene from diabetic Ins2+/- Akita mice. DKO (Ins2+/- /Mmp9-/-) mice revealed improvement in cardiac function, induction of Mef2C and miR-133, and inhibition of LC3 and Atg3 (autophagy). The miR- 133 mitigates myocardial Mmp9 in diabetes by targeting 3'UTR of Mmp9. In addition, treatment with miR- 133 and Mdivi-1(blocker of autophagy) improved cardiac function in diabetic Akita. The central hypothesis of the proposal is that inflammation activates Mmp9 that inhibits Mef2c and miR-133, and induces autophagy resulting into cardiac dysfunction in DM. We will test the hypothesis by the following three specific aims: Aim#1: To determine whether the inflammation induces TNFa and attenuates miR-233 and IL-10 in diabetes. Hypothesis: In diabetes, inflammation induces TNFa and down regulates miR-223 and IL-10. Aim# 2: To determine whether the cardiac fibrosis is due, in part, to activation of Mmp9 and inhibition of Mef2C and miR-133 in diabetes. Hypothesis: In diabetes, activation of Mmp9 attenuates Mef2c and miR-133, and induces cardiac fibrosis. Aim # 3: To determine whether the autophagy causes cardiac dysfunction in diabetes. Hypothesis: In diabetes, Mmp9 is robust and it induces autophagy causing cardiac dysfunction. These studies will unravel the roles of inflammation, miR-133 and -223, Mmp9 and autophagy in cardiac dysfunction in diabetes. It will also provide impetus to assess the therapeutic potential of miR- 133 and Mmp9 in diabetic cardiomyopathy.

描述（由申请人提供）：尽管在了解糖尿病并发症方面取得了巨大进步，但其分子机制尚不清楚。 miRNA 的差异表达与糖尿病 (DM) 相关。该项目的长期目标是了解 DM 中 miRNA 的调控。炎症会诱导肿瘤坏死因子α (TNFa) 和基质金属蛋白酶-9 (Mmp9)，并减弱白细胞介素-10 (IL-10) 和 miR-223。此外，肌球蛋白增强因子 -2c（Mef2C：miR-133（抗肥厚和抗纤维化）诱导剂）下调，微管相关蛋白 1 轻链 3 (LC3)、自噬相关基因 3 (Atg3) 和 beclin-1 （自噬标记物）被诱导。我们报道 Mmp9 损害心肌细胞的收缩性并增加纤维化，而 Mmp9 的消融则改善收缩性并上调 miR-133。然而，Mmp9 和 miR-133 轴在自噬和 DM 中的作用尚不清楚。我们的初步研究表明，糖尿病心脏中 TNFa 被诱导，IL-10 和 miR-223 减弱。有趣的是，TNFa 在肥大的心肌细胞中具有很强的作用。为了研究糖尿病中 Mmp9 介导的 miR-133 和自噬调节机制，我们通过删除糖尿病 Ins2+/- Akita 小鼠的 Mmp9 基因来创建双敲除 (DKO)。 DKO (Ins2+/- /Mmp9-/-) 小鼠显示出心脏功能的改善、Mef2C 和 miR-133 的诱导以及 LC3 和 Atg3（自噬）的抑制。 miR-133通过靶向Mmp9的3'UTR来减轻糖尿病中的心肌Mmp9。此外，用 miR-133 和 Mdivi-1（自噬阻断剂）治疗可改善糖尿病秋田犬的心脏功能。该提案的核心假设是炎症激活 Mmp9，抑制 Mef2c 和 miR-133，并诱导自噬，导致 DM 患者的心脏功能障碍。我们将通过以下三个具体目标来检验这一假设： 目标#1：确定糖尿病中炎症是否会诱导 TNFa 并减弱 miR-233 和 IL-10。假设：在糖尿病中，炎症会诱导 TNFa 并下调 miR-223 和 IL-10。目标#2：确定糖尿病中心脏纤维化是否部分归因于 Mmp9 的激活以及 Mef2C 和 miR-133 的抑制。假设：在糖尿病中，Mmp9 的激活会减弱 Mef2c 和 miR-133，并诱导心脏纤维化。目标#3：确定自噬是否会导致糖尿病患者的心脏功能障碍。假设：在糖尿病中，Mmp9 很强大，它会诱导自噬，导致心脏功能障碍。 这些研究将揭示炎症、miR-133和-223、Mmp9和自噬在糖尿病心脏功能障碍中的作用。它还将为评估 miR-133 和 Mmp9 在糖尿病心肌病中的治疗潜力提供动力。