O-GlcNAcylation regulates vascular smooth muscle cells in diabetic vasculopathy

O-GlcNAc 酰化调节糖尿病血管病变中的血管平滑肌细胞

• 批准号: 9211306
• 负责人: Yabing Chen
• 金额: $ 32.71万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2019-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9211306
• 关键词: Ablation; Anabolism; Arteries; Biological Process; Blood Vessels; Calcified; Cardiovascular system; Clinical; Collaborations; Complications of Diabetes Mellitus; Coronary artery; Data; Development; Diabetes Mellitus; Diabetic mouse; Dose; Enzymes; Event; Excision; Exhibits; Genes; Glucosamine; Glucose; Hexosamines; Human; Hyperglycemia; In Vitro; Injection of therapeutic agent; Insulin; Investigation; Knockout Mice; Link; Mediating; Molecular; Morbidity - disease rate; Mus; Muscle Cells; Mutant Strains Mice; Mutation; O-GlcNAc transferase; Oxidative Stress; Pathway interactions; Patients; Pharmaceutical Preparations; Phenotype; Phosphorylation; Play; Post-Translational Protein Processing; Prevention therapy; Process; Production; Protein-Serine-Threonine Kinases; Proteins; Proto-Oncogene Proteins c-akt; Regulation; Reporting; Role; Signal Transduction; Site; Smooth Muscle; Smooth Muscle Myocytes; Streptozocin; Stress-Induced Protein; Tissues; Ubiquitination; Vascular Diseases; Vascular Smooth Muscle; Vascular calcification; calcification; cell dedifferentiation; diabetic; diabetic patient; in vivo; insight; knock-down; mineralization; mortality; mouse model; multidisciplinary; novel; novel strategies; novel therapeutics; osteogenic; peptide O-linked N-acetylglucosamine-beta-N-acetylglucosaminidase; prevent; public health relevance; sugar; tool; transcription factor; ubiquitin-protein ligase

DESCRIPTION (provided by applicant): Vascular calcification is prevalent in patients with diabetes mellitus, which increases their morbidity and mortality. Hyperglycemia is a hallmark of diabetes that leads to adverse vascular complications. Emerging clinical and basic investigations support a strong correlation between hyperglycemia and vascular calcification. However, the precise role of hyperglycemia in regulating vascular calcification and the underlying molecular mechanisms remain unknown. Osteogenic differentiation and calcification of vascular smooth muscle cells (VSMC) directs vascular calcification in the media and intima of diabetic vasculature. Conditions associated with diabetes, including high glucose and oxidative stress, have been reported to induce VSMC calcification in culture. We have found that oxidative stress and high glucose increase the expression of the osteogenic transcription factor Runx2, which is essential and sufficient to induce VSMC calcification in vitro and in vivo. Increased protein modification by O-linked ß-N-acetyl-glucosamine (O-GlcNAcylation) was observed in diabetic arteries from human and mice, which was associated with increased Runx2 and vascular calcification. O-GlcNAcylation is a dynamic and tightly regulated process, which is as common and ubiquitous as phosphorylation and plays a key role in the regulation of diverse biological processes. O-GlcNAcylation is catalyzed by two enzymes, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), which catalyze the transfer and removal of O-GlcNAc on target proteins, respectively. Glucose metabolized via the hexosamine biosynthesis pathway increases the production of UDP-GlcNAc, an active sugar donor for O-GlcNAcylation, which elevates O-GlcNAcylation. Increased O-GlcNAcylation has been associated with the adverse cardiovascular effects of diabetes. Our preliminary results demonstrated that high glucose and oxidative stress increased VSMC O-GlcNAcylation and calcification. Elevation of O-GlcNAcylation via OGA knockdown promoted VSMC calcification. Moreover, deletion of OGT not only decreased high glucose and oxidative stress-induced protein O-GlcNAcylation in VSMC, but also blocked VSMC calcification. Therefore, we hypothesize that inhibition of O-GlcNAcylation by OGT deletion in VSMC decreases vascular calcification in diabetes. Using our newly generated inducible SMC-specific OGT knockout mouse model, we will 1) determine the role of OGT-mediated O-GlcNAcylation in diabetic vascular calcification in vivo; and 2) elucidate O-GlcNAcylation-dependent molecular signals that regulate vascular calcification. These studies will provide important molecular insights into developing new strategies or drugs to prevent or treat vascular calcification in diabetes and other vascular diseases featuring increased O-GlcNAcylation.

描述(申请人提供)：血管钙化在糖尿病患者中很普遍，这增加了他们的发病率和死亡率。高血糖是糖尿病的一个标志，会导致不利的血管并发症。新出现的临床和基础研究支持高血糖和血管钙化之间的强烈相关性。然而，高血糖在调节血管钙化中的确切作用和潜在的分子机制仍不清楚。血管平滑肌细胞(VSMC)的成骨分化和钙化引导糖尿病血管中层和内膜的血管钙化。与糖尿病相关的条件，包括高糖和氧化应激，已被报道在培养中诱导VSMC钙化。我们发现氧化应激和高糖增加了成骨转录因子Runx2的表达，在体外和体内诱导VSMC钙化是必要的和充分的。在人和小鼠的糖尿病动脉中，观察到O-连接的N-乙酰-氨基葡萄糖(O-GlcNacylation)增加了蛋白质修饰，这与Runx2增加和血管钙化有关。O-GlcN酰化是一个动态的、严格调控的过程，与磷酸化一样常见和普遍，在多种生物过程的调控中起着关键作用。O-GlcNAc酰化反应由O-GlcNAc转移酶(OGT)和O-GlcNAcase(OGA)两种酶催化，它们分别催化O-GlcNAc在靶蛋白上的转移和去除。通过己糖胺生物合成途径代谢的葡萄糖增加了UDP-GlcNAc的产生，UDP-GlcNAc是O-GlcN酰化的活性糖供体，从而促进O-GlcN酰化。O-GlcN酰化增加与糖尿病对心血管的不良影响有关。我们的初步结果表明，高糖和氧化应激增加了VSMC O-GlcN酰化和钙化。通过OGA基因敲除上调O-GlcN酰化促进VSMC钙化。此外，OGT的缺失不仅降低了高糖和氧化应激诱导的VSMC蛋白O-GlcN酰化，而且还阻止了VSMC的钙化。因此，我们假设OGT缺失抑制VSMC中的O-GlcN酰化可减少糖尿病患者的血管钙化。利用我们新建立的可诱导的SMC特异性OGT基因敲除小鼠模型，我们将1)确定OGT介导的O-GlcN酰化在体内糖尿病血管钙化中的作用；2)阐明O-GlcN酰化依赖的调节血管钙化的分子信号。这些研究将为开发新的策略或药物以预防或治疗糖尿病和其他以O-GlcN酰化为特征的血管疾病的血管钙化提供重要的分子见解。