Glycation of Protein in Diabetes

这项研究计划解决了这样一个假设，即蛋白质和其他生物分子通过 非酶糖基化和美拉德或褐变反应有助于长期 糖尿病的并发症。提出的机制包括形成不可逆的晚期糖基化。 和脂氧化终末产物(AGE/ALE)，影响蛋白质结构和功能并改变体内代谢 出现并发症的组织。我们已经通过评估以下因素的影响来检验美拉德假说 AGE/ALE抑制剂对动物蛋白质化学修饰和并发症发生的影响 糖尿病模型，包括链脲佐菌素-糖尿病和Zucker肥胖大鼠。这些研究提出了 关于AGE/ALE抑制剂对蛋白质酶交联的影响的问题，导致了 半胱氨酸衍生的一类新的AGE/ALE的鉴定，并对羰基有了深入的了解 AGE/ALE抑制剂吡哆胺(PM)的捕集活性及其作用机理在.期间 在这笔赠款的续行期内，我们的具体目标是：1)评估糖尿病、高脂血症的影响 和AGE/ALE抑制剂对酶和非酶、化学修饰和 胶原蛋白中的交联物，包括体内AGE/ALE抑制剂的螯合活性的研究；2)研究 Cys-AGE/ALES在糖尿病和高脂血症中的形成及其生物学意义 蛋白质巯基与乙二醛、甲基乙醛和富马酸反应的比较研究 胞内和胞外蛋白中Cys-AGE/ALE水平的变化，AGE/ALE处理的影响- Cys-AGE/ALE修饰的主要细胞内蛋白的鉴定，以及对 Cys-AGE/ALE形成的调控意义；3)继续对PM的研究，以确定反应性 该化合物在体内外捕获的中间体，以评价PM对二羰基水平的影响 血浆中的中间体，并评价PM对AGE/ALE形成和发展的影响 非高脂血症动物模型易患糖尿病的BB/WOR大鼠的病理学。通过这项工作，我们希望 为了更好地了解AGE/ALE在糖尿病并发症发病机制中的作用 AGE/ALE抑制剂的作用机制，最终导致更有效的开发 糖尿病及其并发症的治疗方法。

This research program addresses the hypothesis that damage to proteins and other biomolecules by nonenzymatic glycation and Maillard or browning reactions contributes to the pathogenesis of the long-term complications of diabetes. The proposed mechanism involves formation of irreversible advanced glycation and lipoxidation end-products (AGE/ALEs) that affect protein structure and function and alter metabolism in tissues in which complication develop. We have tested the Maillard hypothesis by evaluating the effects of AGE/ALE inhibitors on the chemical modification of proteins and development of complications in animal models of diabetes, including the streptozotocin-diabetic and Zucker obese rat.These studies have raised questions about the effects of AGE/ALE inhibitors on enzymatic crosslinking of proteins, have led to the identification of a new class of AGE/ALEs derived from cysteine, and have yielded insight into the carbonyl trapping activity and mechanism of action of the AGE/ALE inhibitor pyridoxamine (PM). During the continuation period of this grant, our Specific Aims are: 1)to evaluate the effects of diabetes, hyperlipidemia and AGE/ALE inhibitors on the formation of enzymatic, as well as nonenzymatic, chemical modifications and crosslinks in collagen, including studies on the chelating activity of AGE/ALE inhibitors in vivo; 2) to study the formation and biological significance of Cys-AGE/ALEs in diabetes and hyperlipidemia, including basic research on the reaction of protein sulfhydryl groups with glyoxal, methylglyoxal and fumarate, comparison of levels of Cys-AGE/ALEs in intracellular and extracellular proteins, effects of treatment with AGE/ALE- inhibitors, identification of major intracellular proteins modified by Cys-AGE/ALEs, and evaluation of the regulatory significance of Cys-AGE/ALE formation; 3) to continue studies on PM in order to identify reactive intermediates trapped by this compound in vitro and in vivo, to evaluate effects of PM on levels of dicarbonyl intermediates in plasma, and to evaluate the effects of PM on AGE/ALE formation and development of pathology in a non-hyperlipidemic animal model, the diabetes prone BB/Wor rat.Through this work, we hope to gain a better understanding of the role of AGE/ALEs in the pathogenesis of diabetic complication and the mechanism of action of AGE/ALE inhibitors, leading eventually to the development of more effective therapies for treatment of diabetes and its complications.