Role of Aldose Reductase in Diabetic Complications

醛糖还原酶在糖尿病并发症中的作用

• 批准号: 8007485
• 负责人: SATISH K SRIVASTAVA
• 金额: $ 8.5万
• 依托单位: UNIVERSITY OF TEXAS MED BR GALVESTON
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-12-31 至 2010-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8007485
• 关键词: Ablation; Affect; Alcohols; Aldehyde Reductase; Aldehydes; Animal Model; Antibodies; Aorta; Apoptosis; Arts; Attenuated; Binding; Binding Sites; Biochemical; Blood Vessels; Budgets; Complex; Complications of Diabetes Mellitus; Core Facility; Cytokine Signaling; Development; Diabetes Mellitus; Electrospray Ionization; Functional disorder; Funding; Gel; Generations; Genomics; Glucose; Glutathione; Glutathione S-Transferase; Goals; Grant; Hyperglycemia; Hyperplasia; Inflammation; Inflammatory; Insulin Resistance; Investigation; Isoenzymes; Knockout Mice; Lead; Lipids; MAP Kinase Gene; MAPK8 gene; Mediating; Molecular; Molecular Models; Monitor; Mus; Mutation; Nature; Nitrosation; Oxidases; Oxidation-Reduction; Oxidative Stress; PRKCB1 gene; Pathway interactions; Phosphorylation; Phosphotransferases; Physiological; Post-Translational Protein Processing; Process; Production; Protein Kinase; Proteins; Proteomics; Reactive Oxygen Species; Research Personnel; Role; Serine; Signal Transduction; Site; Smooth Muscle Myocytes; Spectrometry; Stress; Structure; TANK-binding kinase 1; TNF-alpha converting enzyme; Techniques; Testing; Therapeutic; Tissue Inhibitor of Metalloproteinases; Toxic effect; Transcription Factor AP-1; Vascular Endothelial Cell; autocrine; base; clinical efficacy; cytokine; cytotoxic; cytotoxicity; diabetic; diabetic rat; enzyme pathway; glutathione analog; improved; in vivo; inflammatory marker; inhibitor/antagonist; microbial alkaline proteinase inhibitor; molecular modeling; mutant; novel therapeutic intervention; paracrine; payment; polyol; prevent; protein kinase C beta; receptor; transcription factor

The polyol pathway enzyme aldose reductase (AR) has been implicated in several pleiotrophic complicationsof diabetes. In animal models, AR inhibitors (ARI) prevent or delay multiple diabetic complications. However, the clinical efficacy of ARI remains uncertain, and the physiological role of AR is unclear. Our results during the current funding period show that AR-catalyzed reduced products of lipid aldehydes-glutathione conjugates (such as GS-DHN, glutathione dihydroxynonane), formed under hyperglycemia-induced oxidative stress, mediate NF-KB and API activation that increases inflammatory markers. We have shown that nitrosation activates and glutathiolation inactivates AR. Our central hypothesis is that by altering the cellular redox state, and inducing post-translational modifications, prolonged diabetes perturbs the redox poise and stress signaling leading to an increase in cytokine production and inflammation which in turn induces or exacerbates secondary diabetic complications. To test this hypothesis, we will extend the studies to understand the mechanistic relationship between hyperglycemia and inflammation and identify the role of AR in cytokine production and inflammation. Specifically our aim is to continue our investigations to further understand the mechanisms by which AR mediates hyperglycemia-induced activation of PKC and TACE that cause TNF-a secretion leading to smooth muscle cell hyperplasia, vascular endothelial cell apoptosis, inflammation, and insulin resistance. Accordingly,the aims are extension of the current grant. Completion of our aims will verify our hypothesis and identify the mechanisms through which AR could mediate hyperglycemia- induced inflammatory signals that cause secondary diabetic complicationsincluding insulin resistance. Also the results of additional structural studies on AR would help us in developing more specific and targeted inhibitor(s) of AR. Thus the aims of the next five years are to: (1) investigate the mechanisms by which reduced lipid aldehydes-glutathione conjugates (such as GS-DHN) in hyperglycemia activate PKC and NF-KB and trigger inflammation; (2) delineate the role of AR in regulating TNF-a production during hyperglycemia; (3) identify protein kinase(s) activated by AR- catalyzed reduced lipid aldehydes-glutathione conjugates (GS-DHN) that phosphorylate PKC; and (4) develop specific and targeted aldose reductase inhibitors. Based on our recent crystal structure of the AR-NADPH-glutathione analogue ternary complex and biochemical analysis of the glutathione binding site of AR, molecular modeling, site-directed mutations will be performed to further probe glutathione binding site and the nature of the interaction between AR and glutathione conjugates. This will help in developing structure-based AR inhibitors which will prevent the binding of GS-HNE without affecting the binding and reduction of toxic lipid aldehydes such as HNE. This approach is potentially important in minimizing the toxicity of AR inhibitors thereby greatly improvingthe therapeutic application of AR inhibitors.

多元醇途径酶--醛糖还原酶(AR)参与了多种多种营养并发症的发生。 糖尿病。在动物模型中，AR抑制剂(ARI)可预防或延缓多种糖尿病并发症。然而， ARI的临床疗效尚不确定，AR的生理作用也不清楚。我们在目前的业绩 资助期显示，AR催化的脂醛-谷胱甘肽结合物的还原产物(如GS-DHN， 在高血糖诱导的氧化应激下形成的谷胱甘肽(GSH)介导了核因子-KB和API 增加炎症标志物的激活。我们已经证明了亚硝化和谷胱甘肽的活化。 停用AR。我们的中心假设是，通过改变细胞的氧化还原状态，并诱导翻译后 修饰，长期糖尿病扰乱氧化还原平衡和压力信号导致细胞因子增加 产生和炎症，进而导致或加重继发性糖尿病并发症。为了测试这一点 假设，我们将扩大研究，以了解高血糖和 并确定AR在细胞因子产生和炎症中的作用。明确地说，我们的目标是继续 为进一步了解AR介导高血糖诱导的血管紧张素转换酶激活的机制 PKC和TACE引起肿瘤坏死因子-α分泌导致血管内皮细胞增殖 细胞凋亡、炎症和胰岛素抵抗。因此，目标是延长目前的赠款。完成 将验证我们的假设，并确定AR调节高血糖的机制- 诱导炎症信号，导致继发性糖尿病并发症，包括胰岛素抵抗。还有结果 对AR进行更多的结构研究将有助于我们开发更具特异性和靶向性的AR抑制剂(S)。因此， 未来五年的目标是：(1)研究降低脂醛-谷胱甘肽的机制 高血糖中的偶联物(如GS-dhn)激活PKC和NF-KB并引发炎症；(2)描绘 AR在高血糖时调节肿瘤坏死因子-α产生中的作用；(3)鉴定AR-α激活的蛋白激酶S。 催化还原脂醛-谷胱甘肽偶联物(GS-DHN)，使PKC磷酸化；以及(4)发展特定的 和靶向的醛糖还原酶抑制剂。基于我们最近合成的AR-NADPH-谷胱甘肽类似物的晶体结构 AR三元络合物和谷胱甘肽结合部位的生化分析，分子模拟，定点定位 将进行突变以进一步探测谷胱甘肽结合部位以及AR和AR之间相互作用的性质 谷胱甘肽结合物。这将有助于开发基于结构的AR抑制剂，它将防止结合 GS-HNE不影响HNE等有毒脂醛的结合和还原。这种方法是 对将AR抑制剂的毒性降至最低从而大大改善治疗应用具有潜在的重要意义 AR抑制剂。