The genetic basis for tissue specific sensitivities to mitochondrial stress

组织对线粒体应激特异性敏感性的遗传基础

基本信息

批准号：
8216629
负责人：
PATRICK H O'FARRELL
金额：
$ 34.13万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-09-19 至 2016-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8216629
关键词：
Address Affect Alleles Biosensor Blindness Cells Chemicals Complex DNA Sequence Defect Development Diagnosis Disease Dose Drosophila genus Ectopic Expression Engineering Environment Environmental Risk Factor Experimental Models Exposure to Eye Failure Fertility Functional disorder Gene Mutation Genes Genetic Genetic Models Genetic Polymorphism Goals Growth Healthcare Human Hypertrophy Lead Mammals Mitochondria Modeling Mutate Mutation Mutation Detection Nature Nuclear Oligomycins Oxidative Phosphorylation Parkin gene Pharmaceutical Preparations Phenotype Point Mutation Population Protein Isoforms Proteins RNA Interference Respiratory Chain Role Rotenone Specificity Sterility Stress Syndrome Testing Testis Tissues Toxic effect Toxicant exposure Toxin Ursidae Family Work base cell growth cell transformation cell type chemical genetics cytochrome c cytochrome c oxidase empowered environmental chemical fly improved inhibitor/antagonist male mitochondrial dysfunction mitochondrial genome mutant novel strategies research study sensor stressor tool toxicant transdetermination tumor progression

项目摘要

DESCRIPTION (provided by applicant): The goal of this proposal is to understand how mutations and inhibitors that disrupt general mitochondrial functions can cause syndromes with marked tissue specificity. This team is developing new experimental models in which they can exploit the powerful genetic tools in Drosophila to bear on this question. The intent is to test whether tissue specificity of genetic and chemical stressors occurs because they target interactions between general mitochondrial functions and tissue specific genes. A particular mutant of Drosophila Cytochrome oxidase subunit 1 is male sterile, and otherwise normal. It is hypothesized that this highly specific phenotype is the result of failure by this allele to work in conjunction with a testis specific isoform of one of the other respiratory chain proteins. Indeed, ectopic expression of the somatic version of Cytochrome c in testis suppresses the sterility phenotype. The proposed experiments will rigorously test whether this sterility is due to a specific deficit in the partnership of the mutant Cytochrome oxidase and the testis specific isoform of Cytochrome c. Additionally, the fly eye will be engineered as a biosensor for disruption of isoform-specific interactions of mitochondrial functions, and will be applied to identify mutations and chemicals interfering with these interactions. Tissue specificity resulting from synergy of two defects will also be examined, where a tissue specific alteration sensitizes the tissue to diverse genetic and chemical stressors. Eye specific knockdown of E2F compromised growth to produce a slightly reduced eye. It also sensitized the eye to mitochondrial stress. A low dose of oligomycin that is without notable effect in other tissues, synergizes with E2F:RNAi in the eye to produce tissue transformations (e.g. antennae growing out of the eye) and hypertrophy. It is hypothesized that this dysgenesis/hypertrophy relies on two inputs with a biologically universal relationship. Any mutation that inhibits growth of a specific tissue creates a selective environment favoring cells that can escape the growth limitation by transforming to another cell type (transdetermination). A second stress that destabilizes developmental fate would produce the fodder for this selection. Mitochondrial stress appears to provide this destabilizing input. This model will be tested and screened for natural mutations and environmental chemicals contributing to the synergizing inputs. Since mammals express numerous proteins as tissue-specific isoforms, they carry many genes that can mutate to create a selection for transdetermination. Without synergizing input, these mutations would have little impact and could accumulate. Thus, it is suspected that the human population has a large and insidious pool of "polymorphisms" that creates a diversity of chemical sensitivities. Recognition of sensitizing mutations should empower application of DNA sequencing to personalized health-care. PUBLIC HEALTH RELEVANCE: Project Narrative Chemicals or mutations that prevent mitochondria from fulfilling their role as the primary providers of cellular energy cause death, whereas mild mitochondrial stress causes surprisingly complex disruptions in human health. We have developed powerful experimental model in which we will investigate the basis for the complexity of the health defects, and in which we can explore the possibility that chemical perturbation of mitochondrial function has more pervasive influence on human health than is generally recognized.

描述（由申请人提供）：该提案的目的是了解破坏一般线粒体功能的突变和抑制剂如何导致具有明显组织特异性的综合征。该团队正在开发新的实验模型，他们可以利用果蝇强大的遗传工具来解决这个问题。目的是测试遗传和化学应激源的组织特异性是否发生，因为它们针对一般线粒体功能和组织特异性基因之间的相互作用。果蝇细胞色素氧化酶亚基 1 的一种特殊突变体是雄性不育的，其他方面正常。据推测，这种高度特异性的表型是该等位基因未能与其他呼吸链蛋白之一的睾丸特异性亚型结合作用的结果。事实上，睾丸中细胞色素 c 体细胞的异位表达抑制了不育表型。拟议的实验将严格测试这种不育是否是由于突变细胞色素氧化酶和细胞色素 c 睾丸特异性亚型的伙伴关系中的特定缺陷所致。此外，蝇眼将被设计为生物传感器，用于破坏线粒体功能的亚型特异性相互作用，并将用于识别干扰这些相互作用的突变和化学物质。还将检查两种缺陷协同作用产生的组织特异性，其中组织特异性改变使组织对不同的遗传和化学应激源敏感。 E2F 的眼睛特异性敲低会损害生长，导致眼睛轻微缩小。它还使眼睛对线粒体压力敏感。低剂量的寡霉素对其他组织没有显着影响，但与眼睛中的 E2F:RNAi 协同作用，产生组织转化（例如触角从眼睛中长出）和肥大。据推测，这种发育不全/肥大依赖于具有生物学普遍关系的两种输入。任何抑制特定组织生长的突变都会创造一个有利于细胞的选择性环境，这些细胞可以通过转化为另一种细胞类型（转决定）来逃避生长限制。第二种破坏发育命运稳定的压力将为这种选择提供素材。线粒体应激似乎提供了这种不稳定的输入。该模型将被测试和筛选有助于协同输入的自然突变和环境化学物质。由于哺乳动物以组织特异性亚型的形式表达大量蛋白质，因此它们携带许多可以突变以产生转决定选择的基因。如果没有协同输入，这些突变的影响很小，并且可能会累积。因此，人们怀疑人类具有大量潜在的“多态性”，从而产生了化学敏感性的多样性。敏化突变的识别应该能够将 DNA 测序应用于个性化医疗保健。公共健康相关性：项目叙事阻止线粒体发挥其作为细胞能量主要提供者作用的化学物质或突变会导致死亡，而轻微的线粒体应激会对人类健康造成令人惊讶的复杂破坏。我们开发了强大的实验模型，在其中我们将研究健康缺陷复杂性的基础，并在其中探索线粒体功能的化学扰动对人类健康的影响比普遍认识的更普遍的可能性。