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Mechanisms of PhIP-induced dopaminergic neurotoxicity

PhIP 诱导多巴胺能神经毒性的机制

基本信息

批准号：
10595271
负责人：
Jason R Cannon
金额：
$ 156.34万
依托单位：
PURDUE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-09-15 至 2026-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10595271
关键词：
2-Amino-1-Methyl-6-Phenylimidazo[4,5-b]pyridine Address Animal Model Autophagocytosis Biochemical Biological Models Brain Cell model Cells DNA Adduction DNA Adducts DNA Damage Data Data Set Disease Disease model Domestic Fowls Dopamine Environment Exhibits Fishes Genes Genomic DNA Grant Histological Techniques Human Impairment Link Literature Meat Mediating Mitochondria Mitochondrial DNA Mitochondrial Proteins Modeling Molecular Monophenol Monooxygenase Motor Nematoda Nerve Degeneration Neurons Nuclear Outcome Parkinson Disease Pathogenesis Pathologic Pathology Pathway interactions Prevalence Prevention Process Proteins Publications Rattus Research Rodent Model Role Testing Therapeutic Toxic effect Toxicology Translational Research Viral Viral Vector adduct brain metabolism cooking dietary heterocyclic aromatic amines in vivo insight metabolomics mitochondrial dysfunction nervous system disorder neuromelanin neuron loss neurotoxic neurotoxicity novel oxidative damage protein aggregation pyridine toxicant

项目摘要

Dopamine (DA)-ergic neurodegeneration is a pathological hallmark of Parkinson’s disease (PD) that produces the cardinal motor features. Major gaps in the literature remain on if and how common dietary exposures may contribute to pathogenesis. This proposal aims to address these gaps through highly mechanistic studies of neurotoxicity from dietary toxicants known as heterocyclic aromatic amines (HAAs). In the first cycle of R01ES025750, we made major advances demonstrating that HAAs produce selective DAergic neurotoxicity in cellular, nematode, and rodent model systems. We also identified HAA-induced oxidative damage, protein aggregation, autophagy disruption, and DNA adduct formation as key biochemical and molecular outcomes that are of critical importance to PD. Within this dataset, we have made overarching mechanistic advances that set the stage for a mechanism-of-action-focused renewal. First, neuromelanin (NM) is critical to HAA intracellular accumulation and neurotoxicity. This finding points to selectivity because NM is formed in catecholaminergic neurons in humans, and a critical translational need for NM cell and animal models in the study of HAAs (NM is lacking in most PD models). Second, HAAs selectively target mitochondria, again pointing to possible selectivity because DAergic neurons are especially sensitive to mitochondrial toxicity. Based on these data and the literature, we will test the following mechanistic hypothesis: HAA-induced DAergic neurotoxicity is mediated through biochemical interactions between NM and mitochondrial dysfunction that produce a neurotoxic cascade. We will test this hypothesis through three aims. In Aim 1, we will determine if NM-forming rats exhibit heightened HAA-induced DAergic neurotoxicity. In novel, NM-forming rats, we will assess HAA accumulation, HAA brain metabolism, and neurotoxicity to establish PD relevance. In Aim 2, we will identify mitochondrial targets that mediate HAA-induced neurotoxicity. We will discover the role of mitochondrial DNA adducts of HAAs in mediating neurotoxicity by quantifying adducts formed in mitochondrial versus genomic DNA. Further, we will identify HAA bioactivation pathways that lead to mitochondrial and genomic DNA adduct formation. Finally, we will identify specific mitochondrial gene and protein impairments resulting from DNA damage. In Aim 3, we will demonstrate connections between NM, mitochondrial dysfunction, and protein aggregation. Using cell-free, cellular and animal model systems, we will determine the effects of NM on HAA-mediated perturbations of mitochondrial function, autophagy (especially mitophagy), and the propagation of PD-relevant protein aggregation using biochemical and histological techniques. Overall, elucidation of interactions between NM, mitophagy/autophagy, and protein aggregation as critical to HAA neurotoxic mechanism of action is expected to significantly advance understanding of HAA- induced neurotoxicity and, more broadly, environmentally induced DAergic neurotoxicity. These studies are expected to significantly advance understanding of PD etiopathogenesis.

多巴胺 (DA) 能神经变性是帕金森病 (PD) 的病理标志，它会产生主要运动特征。关于常见饮食暴露是否以及如何影响，文献中仍存在主要空白有助于发病。该提案旨在通过高度机械化的研究来解决这些差距被称为杂环芳香胺 (HAAs) 的膳食毒物的神经毒性。在第一个周期中 R01ES025750，我们取得了重大进展，证明 HAA 在细胞、线虫和啮齿动物模型系统。我们还鉴定了 HAA 诱导的氧化损伤、蛋白质聚集、自噬破坏和 DNA 加合物形成是关键的生化和分子结果这对 PD 至关重要。在这个数据集中，我们取得了总体机制上的进步，为以行动机制为重点的更新奠定基础。首先，神经黑色素 (NM) 对 HAA 至关重要细胞内蓄积和神经毒性。这一发现表明了选择性，因为 NM 是在人类儿茶酚胺能神经元，以及 NM 细胞和动物模型的关键转化需求 HAAs 的研究（大多数 PD 模型中缺乏 NM）。其次，HAAs 再次选择性地靶向线粒体指出可能的选择性，因为 DAergic 神经元对线粒体毒性特别敏感。基于根据这些数据和文献，我们将检验以下机制假设：HAA 诱导的 DAergic 神经毒性是通过 NM 和线粒体功能障碍之间的生化相互作用介导的产生神经毒性级联反应。我们将通过三个目标来检验这个假设。在目标 1 中，我们将确定是否 NM 形成大鼠表现出 HAA 诱导的 DAergic 神经毒性增强。在新的、形成 NM 的大鼠中，我们将评估 HAA 积累、HAA 脑代谢和神经毒性以确定 PD 相关性。在目标 2 中，我们将识别介导 HAA 诱导的神经毒性的线粒体靶标。我们将发现的作用通过量化HAA的线粒体DNA加合物在介导神经毒性中形成的加合物线粒体与基因组DNA。此外，我们将确定 HAA 生物激活途径，从而导致线粒体和基因组 DNA 加合物的形成。最后，我们将鉴定特定的线粒体基因并 DNA 损伤导致的蛋白质损伤。在目标 3 中，我们将演示 NM 之间的联系，线粒体功能障碍和蛋白质聚集。使用无细胞、细胞和动物模型系统，我们将确定 NM 对 HAA 介导的线粒体功能、自噬（尤其是线粒体自噬），以及使用生化和组织学方法传播 PD 相关蛋白聚集技术。总体而言，阐明了 NM、线粒体自噬/自噬和蛋白质聚集之间的相互作用 HAA 神经毒性作用机制的关键预计将显着促进对 HAA 的理解诱导的神经毒性，更广泛地说，环境诱导的 DAergic 神经毒性。这些研究是预计将显着促进对 PD 发病机制的了解。