Targeting SNO-GAPDH in inflammatory neurodegeneration and mitochondrial injury

项目总结/摘要 虽然多发性硬化症（MS）被经典地认为是一种脱髓鞘疾病，但神经轴突缺失发生在多发性硬化症患者中。 疾病的复发和进展阶段，并代表了疾病的主要病理相关性， 能力现有疗法主要针对外周免疫系统，防止临床复发，但在很大程度上 在进行性MS治疗中未能预防神经变性，主要神经保护模式为ac- 运动是当前研究的主要目标，既要减缓进展性MS的残疾，又要限制再运动时的损伤。 尽管有目前的治疗，仍会发生失误。一氧化氮（NO）是一种由中枢神经系统产生的有毒自由基， tem（CNS）巨噬细胞和小胶质细胞，有助于复发性和进行性神经轴突损伤 MS和神经炎症模型中，NO诱导的线粒体功能障碍起主要作用。斯佩 介导这种损伤的特异性、可药物化的信号通路尚未被鉴定。我们建议研究一个 涉及蛋白GAPDH的亚硝基化的候选信号通路。亚硝基化GAPDH（SNO-GAPDH） 易位到细胞核和线粒体，在细胞死亡和核靶点中发挥作用， SIRT 1和PGC-1α，对线粒体生物能量学至关重要。此外，SNO-GAPDH信号传导可以是 被CGP 3466阻断，CGP 3466是一种高度特异性的口服CNS渗透药物，具有既定的人体安全性 和临床翻译的低门槛。我们有初步证据表明SNO-GAPDH信号是活跃的 在神经炎症实验性自身免疫性脑脊髓炎（EAE）小鼠模型中，以及在白色 从MS患者死后获得的物质组织。我们发现，系统性地给予 CGP 3466减轻C57 BL/6 MOG 35 -55/CFA EAE的神经功能障碍并预防神经元损伤 线粒体呼吸在培养的神经元暴露于NO。在拟议的研究中，我们计划充分charac- MOG 35 -55/CFA EAE和死后人MS组织中的HISNO-GAPDH途径活性。我们会阻止- 我是否CGP 3466在EAE中的保护作用来自于主要的神经保护机制， 依赖于外周免疫效应，将其与当前疗法区分开来，并建立其临床前 潜力最后，我们将通过评估SNO-GAPDH对神经元线粒体的影响来寻求机制上的见解。 神经功能。这一机制和临床前治疗研究的积极结果将建立一个 更广泛地为MS和神经炎性疾病提供新的治疗方法。PI的职业发展 该计划将在免疫学、神经炎症模型和线粒体方面提供新的培训机会。 生物能量学，为未来独立研究炎症性神经变性提供基础。

PROJECT SUMMARY/ABSTRACT Although multiple sclerosis (MS) is classically considered a demyelinating disease, neuro-axonal loss occurs in both relapsing and progressive phases of the disease and represents the primary pathologic correlate of disa- bility. Existing therapies primarily target the peripheral immune system, preventing clinical relapses but largely failing to prevent neurodegeneration in progressive MS. Therapies with a primary neuroprotective mode of ac- tion are a major goal of current research, both to slow disability in progressive MS and to limit injury when re- lapses occur despite current therapies. Nitric oxide (NO), a toxic free radical produced by central nervous sys- tem (CNS) macrophages and microglia, contributes to neuro-axonal injury in both relapsing and progressive MS and in models of neuroinflammation, with NO-induced mitochondrial dysfunction playing a major role. Spe- cific, druggable signaling pathways that mediate this injury have not been identified. We propose to study a candidate signaling pathway involving nitrosylation of the protein GAPDH. Nitrosylated GAPDH (SNO-GAPDH) translocates to both nucleus and mitochondria, with an established role in cell death and nuclear targets, such as SIRT1 and PGC-1α, critical for mitochondrial bioenergetics. Moreover, SNO-GAPDH signaling can be blocked by CGP3466, a highly specific, oral CNS-penetrant drug with an established safety profile in humans and a low threshold for clinical translation. We have preliminary evidence that SNO-GAPDH signaling is active in an experimental autoimmune encephalomyelitis (EAE) mouse model of neuroinflammation, and in white matter tissue obtained post-mortem from MS patients. We have found that systemic administration of CGP3466 attenuates neurologic disability in C57BL/6 MOG35-55/CFA EAE and prevents impairment of neuronal mitochondrial respiration in cultured neurons exposed to NO. In the proposed studies, we plan to fully charac- terize SNO-GAPDH pathway activity in MOG35-55/CFA EAE and post-mortem human MS tissue. We will deter- mine whether the protective effects of CGP3466 in EAE derive from a primary neuroprotective mechanism in- dependent of peripheral immune effects, differentiating it from current therapies and establishing its pre-clinical potential. Finally, we will seek mechanistic insights by evaluating the effects of SNO-GAPDH on neuronal mito- chondrial function. Positive results from this mechanistic and pre-clinical therapeutic research will establish a new therapeutic approach for MS and neuroinflammatory disease more broadly. The PI's career development plan will provide new training opportunities in immunology, models of neuroinflammation, and mitochondrial bioenergetics, providing a foundation for future independent studies of inflammatory neurodegeneration.