NAD+ and SIRT1 Regulate Mitochondrial Function in Diabetic Neuropathy

项目摘要/摘要 这项提议的理由是，目前还没有特定的药物可以预防或逆转 人类的糖尿病神经病变，这是科学知识的一大空白。氧化应激和 线粒体功能障碍被认为是神经退行性疾病的重要致病因素。 以及糖尿病神经病变。我们的中心假设是烟酰胺核苷(NR)和烟酰胺 单核苷酸(NMN)是在烟酰胺单核苷酸存在的情况下的前体 腺苷转移酶2(Nmnat2)可增加周围神经系统组织中NAD+的水平。这又反过来 激活SIRT1，进而激活下游转录因子，从而不同地调节特定的mt 优化线粒体呼吸，防止线粒体退变的复合体。我们的目标是确定NR或 NMN可用于实验性糖尿病神经病变的治疗，检测SIRT1-PGC-1α 信号通路为神经病的治疗提供分子靶点，识别潜在的mt呼吸道 可能对治疗有反应的链状靶标，决定将NMN转化为NAD的轴突酶， Nmnat2存在于糖尿病动物和人类皮肤活检组织中再生的轴突中，如果 Nmnat2的测定可能有助于作为对NR反应的标志。在方法上，我们将使用各种 分子、电生理学和病理学工具，以达到研究的目的。1型动物模型 2糖尿病将被用来确定NAD+和SIRT1过表达在神经病变中的作用。在……里面 我们将操作NAD+和SIRT1来评估对整体mt的影响 功能和特异性mt呼吸复合体。Nmnat2水平将在对照和年龄中确定 性别匹配的皮肤活检来自不同严重程度的糖尿病和糖尿病神经病变患者。这个 初步调查结果支持该提案的总体目标，并提供了令人振奋的证据 NMN将为糖尿病神经病变提供潜在的治疗方法，而NAD+激活SIRT1- PGC-1α信号通路在调节线粒体呼吸中起重要作用。该项目的状态基于我们的 最近的文献表明，前列腺素C-1α在糖尿病神经病变的线粒体功能调节中起着关键作用 PGC-1α基因敲除可加重神经病变。这项新颖的研究将检查上游激活因子 PGC-1α，即SIRT1在糖尿病神经病变中的作用，有助于进一步探索一种新的潜在治疗方法 及时纳入临床研究。

PROJECT SUMMARY/ABSTRACT The rationale for this proposal is that there is currently no specific medication that prevents or reverses diabetic neuropathy in humans and this is a major gap in scientific knowledge. Oxidative stress and mitochondrial (Mt) dysfunction are recognized as important causative factors in neurodegenerative disease and in diabetic neuropathy. Our central hypothesis is that nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) are precursors that in the presence of nicotinamide mononucleotide adenylyltransferase 2 (Nmnat2) increase tissue NAD+ levels in the peripheral nervous system. This in turn activates SIRT1, and in turn downstream transcription factors, which differentially regulate specific Mt complexes to optimize Mt respiration and prevent Mt degeneration. Our objectives are to determine if NR or NMN can be used as a therapy for experimental diabetic neuropathy, determine if the SIRT1- PGC-1α signaling pathway provides molecular targets for treatment of neuropathy, identify potential Mt respiratory chain targets that may respond to treatment, determine if the axonal enzyme that converts NMN to NAD, Nmnat2, is present in regenerating axons in skin biopsies from diabetic animals and human subjects and if measurement of Nmnat2 may be useful as a marker for response to NR. In the Methods, we will use a variety of molecular, electrophysiology, and pathology tools to achieve the aims of the study. Animal models of type 1 and 2 diabetes will be used to determine the effect of NAD+ and SIRT1 overexpression on neuropathy. In isolated Mt or whole DRG neurons we will manipulate NAD+ and SIRT1 to assess the effect on overall Mt function and specific Mt respiratory complexes. Nmnat2 levels will be determined in control and age and gender matched skin biopsies from subjects with different severity of diabetes and diabetic neuropathy. The preliminary findings support the overall objectives of the proposal and provide promising evidence that NR and NMN would provide a potential therapy for diabetic neuropathy and that NAD+ activation of the SIRT1- PGC-1α signaling pathway is important in regulating Mt respiration. The status of the project based on our recent manuscripts shows that PGC-1α has a key role in regulating Mt function in diabetic neuropathy and that knockdown of PGC-1α intensifies the neuropathy. This novel research will examine the upstream activator of PGC-1α, namely SIRT1 in diabetic neuropathy and help further explore a new potential therapy (NR) that can be taken into clinical studies in a timely manner.