Defining the cellular and molecular mechanisms of how toxicants disrupt mitochondrial DNA homeostasis

定义毒物如何破坏线粒体 DNA 稳态的细胞和分子机制

基本信息

批准号：
10291547
负责人：
Matthew J Young
金额：
$ 46.34万
依托单位：
SOUTHERN ILLINOIS UNIVERSITY CARBONDALE
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-08-04 至 2024-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10291547
关键词：
Address Adult Affect Air Automobile Driving Autophagocytosis Awareness Biochemical Bioenergetics Cell Cycle Cell Differentiation process Cells Chemicals Cosmetics DNA Damage DNA Maintenance DNA Repair DNA Sequence Alteration DNA biosynthesis DNA copy number Data Defect Degradation Pathway Deletion Mutation Development Disease Environmental Pollution Equilibrium Exposure to Fluorescent Probes Food Food Packaging Foundations Furniture Future General Population Genome Genotype Goals HIV Hepatocyte Homeostasis Individual Knowledge Lead Longevity Maintenance Mammalian Cell Measures Mediating Medical Device Metabolism Mitochondria Mitochondrial DNA Mitochondrial DNA depletion syndromes Mitochondrial Diseases Mitotic Molecular Muscle Muscle Fibers Myoblasts Nuclear Nucleosides Organ Organelles Oxidative Phosphorylation Pathway interactions Pharmaceutical Preparations Pharmacologic Substance Plasticizers Plastics Polyvinyl Chloride Production Proteins Research Reverse Transcriptase Inhibitors Risk Testing Therapeutic Toxic effect Toxicant exposure Toy Undifferentiated Virus Diseases Water Work Zalcitabine exposed human population flexibility food environment genetic variant ground water heteroplasmy interest mitochondrial dysfunction mono-(2-ethylhexyl)phthalate mutant next generation sequencing novel therapeutic intervention phthalates pollutant prevent programs repaired response stressor tissue repair toxicant transmission process treatment strategy

项目摘要

Project summary/abstract Awareness of the toxic effects of drugs and pollutants on mitochondria is growing. Our long-term goal is to understand the molecular mechanisms by which pollutants induce mitochondrial dysfunction and to apply this information to the development of new therapeutic strategies. The widespread exposure of the general population to phthalates has raised significant public concern. Phthalates are added to plastics widely found in food packaging, toys, medical devices, pharmaceuticals, furniture, and cosmetics and they leach out of these products into the food, water, and air. Di-2-ethylhexyl phthalate (DEHP) is abundantly used, and inside the gut, it is hydrolyzed to the active metabolite mono-(2-ethylhexyl) phthalate (MEHP). Recent evidence indicates that phthalates are mitochondrial DNA (mtDNA) toxicants that alter mtDNA copy number. Toxic contaminants that disrupt mitochondrial function may cause mitochondrial disease or place individuals with genetic variants affecting mitochondria at greater risk. This is a very significant concern, as adult mitochondrial disease affects 1 in 4,300 individuals. Furthermore, nucleoside reverse transcriptase inhibitors (NRTIs) used to treat human immunodeficiency virus infection cause mitochondrial toxicity and mimic mitochondrial disease by causing severe mtDNA depletion. The proposed work will address gaps in our knowledge about the molecular mechanisms by which these mtDNA toxicants induce mitochondrial dysfunction. The goal of this project is to determine the molecular mechanisms driving the toxicant-induced variability in mtDNA degradation that we have observed in our preliminary studies of undifferentiated and differentiated cells treated with the NRTI 2',3'- dideoxycytidine (ddC). The function of undifferentiated cells in an organ is to replace cells lost under steady- state conditions and during tissue repair. We predict that mitochondrial pollutants can trigger or contribute to disease by targeting undifferentiated cells. We hypothesize that upon exposure to a mtDNA toxicant, a mitophagy-mediated mtDNA degradation pathway is specifically up-regulated in undifferentiated cells causing significantly higher mtDNA depletion compared to that in differentiated cells. There are two specific aims for this work. First, the disruption of mitochondrial homeostasis in cells treated separately with either MEHP or ddC will be quantified. Following toxicant exposures, we will determine whether undifferentiated cells have increased mtDNA degradation and bioenergetic defects relative to their differentiated counterparts. Also, the extent of toxicant-induced mtDNA deletions and mutations will be determined. Second, the molecular mechanism of toxicant-induced disruption of mtDNA homeostasis will be determined by measuring the expression levels of components of the autophagy/mitophagy and degradosome types of machinery in undifferentiated and differentiated cells. This work is significant because it will elucidate the mechanism of toxicant-mediated mtDNA degradation and thus lay the foundation for future pollutant studies. In the long-term, this work may form the framework for strategies to treat or prevent toxicant-induced mitochondrial damage.

项目摘要/摘要对药物和污染物对线粒体的毒性作用的认识正在增长。我们的长期目标是了解污染物诱导线粒体功能障碍并应用的分子机制信息开发新的治疗策略。将军的广泛暴露邻国人口引起了公众的重大关注。邻苯二甲酸盐被添加到广泛发现的塑料中食品包装，玩具，医疗设备，药品，家具和化妆品，它们从中浸出产品进入食物，水和空气。 DI-2-乙基己基邻苯二甲酸酯（DEHP）大量使用，并且在肠道内部，它被水解为活性代谢产物单（2-乙基己基）邻苯二甲酸酯（MEHP）。最近的证据表明邻苯二甲酸盐是改变mtDNA拷贝数的线粒体DNA（mtDNA）有毒物质。有毒污染物干扰线粒体功能可能会导致线粒体疾病或放置具有遗传变异的个体影响线粒体的风险更大。这是一个非常重要的问题，因为成年线粒体疾病会影响 4,300个人中有1个人。此外，用于治疗人类的核苷逆转录酶抑制剂（NRTI）免疫缺陷病毒感染会引起线粒体毒性和模仿线粒体疾病严重的mtDNA耗竭。拟议的工作将解决我们有关分子的差距这些mtDNA毒性诱导线粒体功能障碍的机制。这个项目的目标是确定驱动毒物诱导的mtDNA降解变异性的分子机制，我们在我们的初步研究中观察到了未分化的和分化的细胞，该细胞用NRTI 2'，3'-- 二氧基胞苷（DDC）。器官中未分化细胞的功能是替代在稳态下丢失的细胞状态条件和组织修复期间。我们预测线粒体污染物会触发或有助于通过靶向未分化的细胞来疾病。我们假设在暴露于mtDNA有毒物品时，线粒体介导的mtDNA降解途径在未分化的细胞中特异性上调，导致引起的细胞与分化细胞相比，mtDNA耗竭明显更高。有两个具体的目标这项工作。首先，用MEHP或MEHP或 DDC将进行量化。毒性暴露后，我们将确定未分化的细胞是否具有相对于其分化的对应物，mtDNA降解和生物能缺陷增加。另外，将确定毒物诱导的mtDNA缺失和突变的程度。其次，分子有毒物质引起的mtDNA稳态破坏的机制将通过测量自噬/线粒体和降解体类型机械的组件的表达水平未分化和分化的细胞。这项工作很重要，因为它将阐明有毒物质介导的mtDNA降解，从而为未来的污染物研究奠定了基础。从长远来看这项工作可能构成了治疗或预防毒物引起的线粒体损害的策略的框架。

项目成果

期刊论文数量（2）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Heterozygous p.Y955C mutation in DNA polymerase γ leads to alterations in bioenergetics, complex I subunit expression, and mtDNA replication.

DOI：
10.1016/j.jbc.2022.102196
发表时间：
2022-08
期刊：
JOURNAL OF BIOLOGICAL CHEMISTRY
影响因子：
4.8
作者：
Rahman, Md Mostafijur;Young, Carolyn K. J.;Goffart, Steffi;Pohjoismaki, Jaakko L. O.;Young, Matthew J.
通讯作者：
Young, Matthew J.

Identification of Somatic Mitochondrial DNA Mutations, Heteroplasmy, and Increased Levels of Catenanes in Tumor Specimens Obtained from Three Endometrial Cancer Patients.

DOI：
10.3390/life12040562
发表时间：
2022-04-09
期刊：
LIFE-BASEL
影响因子：
3.2
作者：
Young, Matthew J.;Sachidanandam, Ravi;Hales, Dale B.;Brard, Laurent;Robinson, Kathy;Rahman, Md Mostafijur;Khadka, Pabitra;Groesch, Kathleen;Young, Carolyn K. J.
通讯作者：
Young, Carolyn K. J.