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（由申请人提供）：血管钙化在糖尿病患者中普遍存在，这会增加其发病率和死亡率。高血糖是糖尿病的一个标志，会导致不良血管并发症。新出现的临床研究和基础研究支持高血糖与血管钙化之间存在很强的相关性。然而，高血糖在调节血管钙化中的确切作用以及成骨分化和钙化的潜在分子机制仍不清楚。血管平滑肌细胞 (VSMC) 指导糖尿病脉管系统中膜和内膜的血管钙化。据报道，与糖尿病相关的病症，包括高葡萄糖和氧化应激，可在培养物中诱导 VSMC 钙化。增加成骨转录因子 Runx2 的表达，这对于体外和体内诱导 VSMC 钙化是必要且充分的。在人类和小鼠的糖尿病动脉中观察到 ß-N-乙酰氨基葡萄糖 (O-GlcNAcylation)，这与 Runx2 增加有关，并且 O-GlcNAcylation 是一个动态且严格调节的过程，与糖尿病一样常见且普遍存在。 O-GlcNAc 磷酸化并在多种生物过程的调节中发挥关键作用，由两种酶 O-GlcNAc 催化。转移酶 (OGT) 和 O-GlcNAcase (OGA)，分别催化目标蛋白上 O-GlcNAc 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- 的活性糖供体。 GlcNAcylation 会升高 O-GlcNAcylation，我们的初步结果表明，O-GlcNAcylation 的增加与糖尿病的不良心血管影响有关。高葡萄糖和氧化应激增加了 VSMC O-GlcNAc 化和钙化。通过 OGA 敲低，O-GlcNAc 化升高促进了 VSMC 钙化。此外，OGT 的缺失不仅降低了 VSMC 中高葡萄糖和氧化应激诱导的蛋白质 O-GlcNAc 化。因此，我们发现通过 VSMC 中 OGT 缺失抑制 O-GlcNAc 化可减少血管。使用我们新生成的诱导型 SMC 特异性 OGT 敲除小鼠模型，我们将 1) 确定 O-GlcNAc 化在体内糖尿病血管钙化中的作用；2) 阐明 O-GlcNAc 化依赖性分子信号这些研究将为开发新策略或药物来预防或治疗糖尿病和其他血管钙化增加的血管疾病提供重要的分子见解。 O-GlcNAc 酰化。