SULT4a1, a novel neuroprotective protein in stroke

在美国，中风仍然是死亡和发病的主要原因， 干预措施。氧化还原失衡和线粒体功能障碍被认为是细胞死亡的主要原因 在中风中。鉴定恢复氧化还原稳态、线粒体功能 细胞的存活是一个关键的需求。过氧化物酶（PRDXs）的失调是导致 氧化还原失衡和线粒体功能障碍PRDX作为双刃剑， 在细胞内以还原形式存在时具有神经保护作用。然而，当氧化和释放时， 由于PRDX可导致细胞受损/死亡，PRDX可通过炎症反应导致继发性细胞死亡信号传导。 因此，在中风中调节PRDXs是一种重要的神经保护策略。我们发现， SULT 4a 1（研究相对较少的神经元蛋白）对PRDXs的作用是一种重要的神经保护功能， SULT 4a 1可能在中风中具有重要的神经保护作用。小鼠神经元中SULT 4a 1的缺失导致 氧化PRDXs的积累伴随着随后的氧化还原失衡、线粒体功能障碍和细胞 死亡SULT 4a 1可以与PRDX 1、PRDX 2、PRDX 3和PRDX 5相互作用。这些PRDXS（细胞溶质-PRDX 1 和PRDX 2，以及细胞质-PRDX 3和PRDX 5）对于细胞溶质和线粒体氧化还原至关重要 通过过氧化物的解毒来保持体内平衡。在此过程中，PRDX被氧化，必须回收 回到简化的形式。SULT 4a 1的表达增加了经过氧化物处理的细胞中还原的PRDX的水平。 细胞SULT 4a 1蛋白水平通过泛素蛋白酶体系统降低卒中。但是，作用 中风中的SULT 4a 1或导致中风中SULT 4a 1丢失的介质尚不清楚。我们会用氧气- 小鼠皮层神经元中的葡萄糖剥夺和中风的大脑中动脉闭塞（MCAO）模型 以确定SULT 4a 1在中风中的神经保护作用。我们提出以下四个研究目标 SULT 4a 1在中风中的作用： 具体目标#1：SULT 4a 1能否通过PRDX维持卒中患者的氧化还原稳态？ 具体目标#2：SULT 4a 1可以挽救中风中的线粒体功能吗？ 具体目标#3：SULT 4a 1在卒中中具有神经保护作用吗？ 具体目标#4：确定导致卒中中SULT 4a 1缺失的机制 我们的支持数据强烈支持我们的假设和提出的目标。联合病毒介导 用Seahorse Flux分析、电子显微镜成像、邻位连接测定、 中风实验模型中的邻近依赖性生物素识别、活细胞成像和MRI成像 代表了一种新的方法来确定SULT 4a 1在中风中的神经保护作用。这些研究将揭示 关于新型SULT 4a 1依赖性通路在卒中中的作用的基本知识，并确定 SULT 4a 1是否可以代表中风治疗干预的可靠靶点。

Stroke remains a leading cause of death and morbidity in the USA and lacks effective therapeutic interventions. Redox imbalance and mitochondrial dysfunction are considered as leading causes of cell death in stroke. Identification of novel therapeutic targets that restore redox homeostasis, mitochondrial function, and cell survival is a critical need. Deregulation in peroxiredoxins (PRDXs) is one of the mechanisms leading to redox imbalance and mitochondrial dysfunction. PRDXs act as double-edged swards that the highly neuroprotective when inside the cells in reduced forms. However, when oxidized and released from damaged/dead cells, PRDXs can lead to secondary cell death signaling via inflammatory responses. Therefore, the regulation of PRDXs in stroke is a vital neuroprotective strategy. We identified that regulation of PRDXs by SULT4a1 (relatively less studies neuronal protein) is a critical neuroprotective function of SULT4a1 and may have a vital neuroprotective role in stroke. Loss of SULT4a1 in mouse neurons leads to the accumulation of oxidized PRDXs with subsequent redox imbalance, mitochondrial dysfunction, and cell death. SULT4a1 can interact with PRDX1, PRDX2, PRDX3, and PRDX5. These PRDXS (cytosolic-PRDX1 and PRDX2, and mitochondrial-PRDX3 and PRDX5) are crucial for cytosolic and mitochondrial redox homeostasis via detoxification of peroxides. During this process, PRDXs are oxidized and must be recycled back to reduced forms. Expression of SULT4a1 increases the levels of reduced PRDXs in peroxide-treated cells. SULT4a1 protein levels decrease in stroke via the ubiquitin proteasomal system. However, the role of SULT4a1 in stroke or the mediators that lead to loss of SULT4a1 in stroke are not known. We will use oxygen- glucose deprivation in mouse cortical neurons and a middle cerebral artery occlusion (MCAO) model of stroke in mice to identify the neuroprotective roles of SULT4a1 in stroke. We propose the following four aims to study the role of SULT4a1 in stroke: Specific Aim #1: Can SULT4a1 maintain redox homeostasis via PRDXs in stroke? Specific Aim #2: Can SULT4a1 rescue mitochondrial function in stroke? Specific Aim #3: Is SULT4a1 neuroprotective in stroke? Specific Aim #4: Identify the mechanisms leading to loss of SULT4a1 in stroke Our supporting data strongly favor our hypothesis and the proposed aims. Combining viral-mediated expression of SULT4a1 with Seahorse Flux analysis, electron microscope imaging, proximity ligation assays, proximity-dependent biotin identification, live-cell imaging, and MRI imaging in experimental models of stroke represents a novel approaches to identify the neuroprotection by SULT4a1 in stroke. These studies will reveal essential knowledge about the role of the novel SULT4a1-dependent pathways in stroke, and determine whether SULT4a1 can represent a credible target for therapeutic intervention in stroke.