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（一种超氧化物与一氧化氮反应的产物）在糖尿病并发症中的重要作用的证据正在出现。使用新的药理学试剂，即，过氧亚硝酸盐分解催化剂和蛋白质硝化抑制剂，iNOS基因敲除小鼠，我们得到的结果牵连过氧亚硝酸盐损伤的整体和蛋白质硝化在早期实验性周围糖尿病神经病变（PDN）。我们发现1）硝基酪氨酸（NT），一种过氧亚硝酸盐损伤的足迹，在链脲佐菌素（STZ）糖尿病和ob/ob小鼠的外周神经、脊髓和DRG神经元中积累; 2）STZ糖尿病iNOS缺陷小鼠与糖尿病野生型小鼠相比不发展神经传导缺陷并且具有较轻的感觉神经病变;和3）过氧亚硝酸盐分解催化剂和较小程度的蛋白质硝化抑制剂，纠正了患有1型和2型糖尿病的小鼠的神经传导缺陷和感觉神经病变。我们还发现，2型糖尿病患者在外周血单核细胞中积累了不同量的硝化蛋白，2型糖尿病受试者的单核细胞NT浓度比非糖尿病组高约75%，吡格列酮治疗减少了皮肤产生的NO（过氧亚硝酸盐的前体）。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催汗反应的重新分布相关，这是交感神经功能障碍的早期迹象。本提案的总体目标是剖析过氧亚硝酸盐和蛋白质硝化在晚期实验性PDN的功能和形态学变化中的作用，并确定血清、外周血单核细胞和皮肤中的NT水平是否可用作糖尿病患者PDN的存在、严重程度和进展的生物标志物。具体目标是：1）评估过氧亚硝酸盐分解催化剂和蛋白质硝化抑制剂是否逆转STZ-糖尿病小鼠和秋田小鼠中晚期PDN的功能、行为和形态学变化; 2）评估血糖控制对PDN、皮肤和循环的组织部位中NT积累和消失的影响;和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、严重性和进展的生物标志物的潜在值。这些发现将促进我们对PDN发病机制的理解，并可能为开发新的治疗方法提供理论基础。它们还可能导致鉴定具有诊断和预后价值的PDN的新生物标志物。 公共卫生相关性：糖尿病周围神经病变（PDN）是糖尿病最严重的并发症，也是导致足部截肢的主要原因。过氧亚硝酸盐（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。本提案的总体目标是剖析过氧亚硝酸盐及其组分之一蛋白质硝化在晚期实验性PDN的功能和形态学变化中的作用，并确定血清、外周血单核细胞和皮肤中的硝基酪氨酸水平是否可用作糖尿病人类受试者PDN的存在、严重程度、发展和进展速率的生物标志物。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;和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、严重性、发展和进展速率的生物标志物的潜在值。这些发现将促进我们对PDN发病机制的理解，并可能为开发新的治疗方法提供理论基础。它们还可能导致鉴定具有诊断和预后价值的PDN的新生物标志物。