Placental identified NHIP regulating neuronal oxidative stress in autism

人类胎儿的大脑消耗了身体60%的氧气和能量， 尽管它只占体重的13%当胎盘对氧气的需求和 发育中的大脑超过其供应，缺氧被诱导，随后是线粒体的变化， 呼吸、蛋白质翻译和氧化应激。氧化应激和表观遗传机制 在胎盘-脑轴中，作用于遗传和环境风险因素的界面， 自闭症谱系障碍使用来自前瞻性高风险队列的胎盘样本，我们 最近发现并命名了一个新的基因NHIP（神经元缺氧诱导，胎盘 相关），并证明了其与自闭症的表观遗传，遗传和转录关联。 NHIP在缺氧和神经元分化时瞬时表达，两个例子 氧化应激升高NHIP编码一种以前未发现的微肽， NHIP的表达较低，因此预测其具有神经保护作用。 胎盘和大脑样本进行比较。NHIP的预测结构 肽是一种两亲性螺旋，其与转录因子中发现的9aaa基序具有相似性。 许多DNA结合蛋白的激活结构域。我们建议测试假设，NHIP 作为多蛋白复合物的竞争性抑制剂，从而保护发育， 在短暂的缺氧波之后分化神经元。因为NHIP是一个“未被发现的 在我们最近的研究之前，蛋白质的功能尚未被描述，这项建议将集中在 对确定治疗相关性至关重要的主要研究问题 NHIP。具体来说，NHIP在神经元和大脑中的功能是什么，它在神经元和大脑中是如何调节的， 反应缺氧，它是保护神经元氧化应激？我们提出三个具体的 目的是使用良好表征的体外和体内模型，包括诱导的人神经元 针对NHIP转录物或肽损失而工程化的细胞系（LUHMES）， 已知NHIP基因型和表达水平，以及小鼠脑中NHIP肽 给药和/或缺氧。目的1：明确NHIP功能的分子机制 并检查NHIP损失的蛋白质特异性和整体细胞影响。目标2将决定 NHIP是如何通过识别缺氧诱导的氧化应激在转录上响应的， 转录因子及其与NHIP结合的遗传和表观遗传要求 启动子和增强子。目标3将确定外源性NHIP/NHIP是否能保护 神经元和胚胎神经前体细胞缺氧诱导的氧化应激。在一起， 来自这些建议的研究的结果将提供NHIP的第一个功能表征， 一种未充分研究的与自闭症谱系障碍的恢复力有关的微肽。的 这些结果的潜在影响将是一种潜在的治疗性小分子， 在自闭症和其他神经发育或缺氧相关早期干预治疗中 紊乱

The human fetal brain consumes up to 60% of the body’s oxygen and energy consumption, despite making up ~13% of body mass. When the demand for oxygen in the placenta and developing brain exceeds its supply, hypoxia is induced, followed by changes to mitochondrial respiration, protein translation, and oxidative stress. Oxidative stress and epigenetic mechanisms within the placental-brain axis act at the interface of genetic and environmental risk factors in autism spectrum disorders. Using placental samples from a prospective high-risk cohort, we recently identified and named a novel gene NHIP (neuronal hypoxia inducible, placenta associated) and demonstrated its epigenetic, genetic, and transcriptional association with autism. NHIP is transiently expressed in response to hypoxia and neuronal differentiation, two examples of elevated oxidative stress. NHIP encodes a previously undiscovered micropeptide that localizes to the nucleus and is predicted to be neuroprotective, based on the lower expression of NHIP in placenta and brain samples from autism compared to control. The predicted structure of the NHIP peptide is an amphipathic helix that has similarity to a 9aaTAD motif found in transcriptional activation domains of many DNA binding proteins. We propose to test the hypothesis that NHIP acts as a competitive inhibitor of multi-protein complexes, thereby protecting developing and differentiating neurons following transient waves of hypoxia. Because NHIP is an “undiscovered protein” whose function had not been described before our recent study, this proposal will focus on the major research questions that are critical for determining the therapeutic relevance of NHIP. Specifically, what is the function of NHIP in neurons and brain, how is it regulated in response to hypoxia, and is it protective of neuronal oxidative stress? We propose three specific aims using well-characterized in vitro and in vivo models, including an inducible human neuronal cell line (LUHMES) engineered for NHIP transcript or peptide loss, human brain extracts with known NHIP genotype and expression levels, and mouse brain following NHIP peptide administration and/or hypoxia. Aim 1 will determine the molecular mechanisms of NHIP function and examine both protein-specific and global cellular impacts of NHIP loss. Aim 2 will determine how NHIP is transcriptionally responsive to hypoxia-induced oxidative stress by identifying the transcription factors and their genetic and epigenetic requirements for binding to the NHIP promoter and enhancer. Aim 3 will determine if exogenously delivered NHIP/NHIP protects neurons and embryonic neural precursor cells from hypoxia-induced oxidative stress. Together, the results from these proposed studies will provide the first functional characterization of NHIP, an understudied micropeptide that is associated with resilience to autism spectrum disorders. The potential impact of these results will be a potential therapeutic small molecule that could be used in early intervention therapy for autism and other neurodevelopmental or hypoxia-related disorders.