Peroxynitrite, protein nitration and advanced diabetic neuropathy

过氧亚硝酸盐、蛋白质硝化和晚期糖尿病神经病变

• 批准号: 8625363
• 负责人: Mark A. Yorek
• 金额: $ 17.28万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8625363
• 关键词: Peroxynitrite; protein; nitration; advanced; diabetic

DESCRIPTION (provided by applicant): Evidence for important role of peroxynitrite, a product of superoxide reaction with nitric oxide, in diabetic complications is emerging. Using new pharmacological agents i.e., peroxynitrite decomposition catalysts and protein nitration inhibitor, and iNOS-knockout mice, we obtained findings implicating peroxynitrite injury in toto and protein nitration in early experimental peripheral diabetic neuropathy (PDN). We found that 1) nitro- tyrosine (NT), a footprint of peroxynitrite injury, accumulates in peripheral nerve, spinal cord, and DRG neurons of streptozotocin (STZ)-diabetic and ob/ob mice; 2) STZ-diabetic iNOS-deficient mice do not develop nerve conduction deficits and have less severe sensory neuropathy compared with diabetic wild-type mice; and 3) peroxynitrite decomposition catalysts and, to a lesser extent, a protein nitration inhibitor, corrected nerve conduction deficits and sensory neuropathy in mice with Type 1 and Type 2 diabetes. We also found that Type 2 diabetic patients accumulate different amounts of nitrated proteins in peripheral blood monocytes, that monocyte NT concentration is ~ 75% greater in Type 2 diabetic subjects compared with non-diabetic group, and that skin production of NO, a precursor of peroxynitrite, is reduced by pioglitazone treatment. Others showed that increased plasma NT content correlated with endothelial dysfunction and redistribution of sudomotor responses, an early sign of sympathetic nerve dysfunction, in diabetic patients. The overall objective of this proposal is to dissect the roles of peroxynitrite and protein nitration in functional and morphological changes of advanced experimental PDN, and to determine if NT levels in serum, peripheral blood monocytes, and skin can be used as biomarkers of the presence, severity, and progression of PDN in human subjects with diabetes. The specific aims are: 1) evaluate if peroxynitrite decomposition catalyst and protein nitration inhibitor reverse functional, behavioral, and morphological changes of advanced PDN in STZ- diabetic and Akita mice; 2) assess the effect of blood glucose control on accumulation and disappearance of NT in tissue-sites of PDN, skin, and circulation; and 3) determine potential values of serum, peripheral blood monocyte, and skin NT levels as biomarkers of the presence, severity, and progression of PDN in human subjects with diabetes mellitus. The findings will advance our understanding of the pathogenesis of PDN, and may provide rationale for development of new therapeutics. They may also lead to identification of a new biomarker(s) of PDN with diagnostic and prognostic value. PUBLIC HEALTH RELEVANCE: Peripheral diabetic neuropathy (PDN) is the most devastating complication of diabetes mellitus, and a leading cause of foot amputation. Evidence for important role of peroxynitrite (a product of superoxide reaction with nitric oxide) in PDN is emerging and is supported by our preliminary data obtained in both diabetic mouse models and human subjects with diabetes mellitus. The overall objective of this proposal is to dissect the roles of peroxynitrite and one of its components, protein nitration, in functional and morphological changes of advanced experimental PDN, and to determine if nitrotyrosine levels in serum, peripheral blood monocytes, and skin can be used as biomarkers of the presence, severity, development and rate of progression of PDN in human subjects with diabetes. The specific aims are: 1) evaluate if peroxynitrite decomposition catalyst or protein nitration inhibitor reverse functional, behavioral, and morphological manifestations of advanced PDN in two mouse models of Type 1 diabetes; 2) assess the effect of blood glucose control on accumulation and disappearance of nitrotyrosine in tissue-sites of PDN, skin, and circulation; and 3) determine potential values of serum, peripheral blood monocyte, and skin nitrotyrosine levels as biomarkers of the presence, severity, development, and rate of progression of PDN in human subjects with diabetes mellitus. The findings will advance our understanding of the pathogenesis of PDN, and may provide rationale for development of new therapeutics. They may also lead to identification of a new biomarker(s) of PDN with diagnostic and prognostic value.

描述（由申请人提供）：过氧亚硝酸盐（一种与一氧化氮的超氧化物反应的产物）在糖尿病并发症中的重要作用的证据正在出现。使用新的药理学制剂，即过氧亚硝酸盐分解催化剂和蛋白质硝化抑制剂，以及 iNOS 敲除小鼠，我们获得了早期实验性周围糖尿病神经病变 (PDN) 中过氧亚硝酸盐损伤和蛋白质硝化的发现。我们发现1）硝基酪氨酸（NT）是过氧亚硝酸盐损伤的足迹，在链脲佐菌素（STZ）糖尿病小鼠和ob/ob小鼠的周围神经、脊髓和DRG神经元中积累； 2）与糖尿病野生型小鼠相比，STZ-糖尿病iNOS缺陷小鼠不会出现神经传导缺陷，感觉神经病变也较轻； 3) 过氧亚硝酸盐分解催化剂，以及较小程度的蛋白质硝化抑制剂，纠正了 1 型和 2 型糖尿病小鼠的神经传导缺陷和感觉神经病变。我们还发现，2 型糖尿病患者的外周血单核细胞中积累了不同量的硝化蛋白，与非糖尿病组相比，2 型糖尿病患者的单核细胞 NT 浓度高出约 75%，并且皮肤产生 NO（NO 的前体）。吡格列酮处理可减少过氧亚硝酸盐。其他研究表明，糖尿病患者血浆 NT 含量增加与内皮功能障碍和促汗反应重新分布相关，这是糖尿病患者交感神经功能障碍的早期征兆。本提案的总体目标是剖析过氧亚硝酸盐和蛋白质硝化在高级实验 PDN 功能和形态变化中的作用，并确定血清、外周血单核细胞和皮肤中的 NT 水平是否可以用作存在的生物标志物，人类糖尿病受试者 PDN 的严重程度和进展。具体目标是：1）评估过氧亚硝酸盐分解催化剂和蛋白质硝化抑制剂是否逆转STZ-糖尿病和秋田小鼠晚期PDN的功能、行为和形态变化； 2）评估血糖控制对PDN、皮肤和循环组织部位NT积累和消失的影响； 3) 确定血清、外周血单核细胞和皮肤 NT 水平作为糖尿病人类受试者中 PDN 的存在、严重程度和进展的生物标志物的潜在值。这些发现将增进我们对 PDN 发病机制的理解，并可能为开发新疗法提供依据。它们还可能导致鉴定具有诊断和预后价值的 PDN 新生物标志物。 公众健康相关性：糖尿病周围神经病变 (PDN) 是糖尿病最具破坏性的并发症，也是导致足部截肢的主要原因。过氧亚硝酸盐（一种超氧化物与一氧化氮反应的产物）在 PDN 中的重要作用的证据正在出现，并得到我们在糖尿病小鼠模型和糖尿病人类受试者中获得的初步数据的支持。该提案的总体目标是剖析过氧亚硝酸盐及其成分之一蛋白质硝化在高级实验 PDN 的功能和形态变化中的作用，并确定是否可以使用血清、外周血单核细胞和皮肤中的硝基酪氨酸水平作为人类糖尿病受试者中 PDN 的存在、严重程度、发生和进展速度的生物标志物。具体目标是：1）评估过氧亚硝酸盐分解催化剂或蛋白质硝化抑制剂是否可以逆转两种1型糖尿病小鼠模型中晚期PDN的功能、行为和形态学表现； 2）评估血糖控制对PDN、皮肤和循环组织部位硝基酪氨酸积累和消失的影响； 3) 确定血清、外周血单核细胞和皮肤硝基酪氨酸水平作为糖尿病人类受试者中 PDN 的存在、严重程度、发生和进展速度的生物标志物的潜在值。这些发现将增进我们对 PDN 发病机制的理解，并可能为开发新疗法提供依据。它们还可能导致鉴定具有诊断和预后价值的 PDN 新生物标志物。