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，缺乏有效的治疗方法 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。确定恢复氧化还原稳态、线粒体功能的新治疗靶点， 而细胞生存是一项至关重要的需求。过氧化还蛋白(PRDX)的解除管制是导致 氧化还原失衡和线粒体功能障碍。PRDX扮演着双刃剑的角色， 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 对于受损/死亡的细胞，PRDX可通过炎症反应导致继发性细胞死亡信号。 因此，调节PRDX在卒中中的作用是一种重要的神经保护策略。我们确认了这一规定 SULT4a1(研究相对较少的神经元蛋白)对PRDX的作用是一种关键的神经保护功能 SULT4a1，并可能在中风中起重要的神经保护作用。小鼠神经元中SULT4a1的缺失导致 氧化的PRDX的积累导致随后的氧化还原失衡、线粒体功能障碍和细胞 死亡。SULT4a1可以与PRDX1、PRDX2、PRDX3和PRDX5交互。这些PRDXS(胞浆-PRDX1 和PRDX2，以及线粒体-PRDX3和PRDX5)是胞质和线粒体氧化还原的关键 通过过氧化物解毒实现的动态平衡。在此过程中，PRDX被氧化，必须回收 回到简化的形式。SULT4a1的表达增加了过氧化处理后PRDX的还原水平 细胞。卒中患者SULT4a1蛋白水平通过泛素蛋白酶体系统降低。然而，它的作用是 卒中中的SULT4a1或导致卒中中SULT4a1丢失的介质尚不清楚。我们将使用氧气- 小鼠皮质神经元缺糖与大脑中动脉闭塞(MCAO)模型的建立 在小鼠中鉴定SULT4a1在中风中的神经保护作用。我们提出了以下四个目标来研究 SULT4a1在卒中中的作用： 具体目标#1：SULT4a1能否通过PRDX维持中风患者的氧化还原动态平衡？ 具体目标2：SULT4a1能否挽救中风患者的线粒体功能？ 具体目标#3：SULT4a1在中风中具有神经保护作用吗？ 具体目标#4：确定导致卒中SULT4a1丢失的机制 我们的支持数据有力地支持了我们的假设和提出的目标。结合病毒介体 用海马氏通量分析、电子显微镜成像、邻近连接试验、 实验性卒中模型的邻近依赖生物素识别、活细胞成像和MRI成像 为鉴定SULT4a1在卒中中的神经保护作用提供了一种新的方法。这些研究将揭示 对新的SULT4a1依赖通路在卒中中的作用的基本知识，并确定 SULT4a1是否能代表卒中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.