Dissecting the role of reproduction in regulating lysosomal function in C. elegans

剖析线虫繁殖在调节溶酶体功能中的作用

• 批准号: RGPIN-2018-03751
• 负责人: EgydiodeCarvalho, Carlos
• 金额: $ 2.62万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=649951
• 关键词: Dissecting; role; reproduction; regulating; lysosomal

Reproduction and aging are linked processes in eukaryotes. Across different species, aging is synchronized with the reproductive cycle such that progeny generation coincides with the time when the animal is the fittest. Mutations in C. elegans that prevent germ cell proliferation also increase longevity, pointing to a genetically regulated cross talk between the gonad and the soma to influence fitness. How this cross-tissue signaling functions during the reproductive cycle, and through which cellular processes it acts in somatic cells, remains unclear. My research group is studying the molecular underpinning of the synchrony between reproduction and somatic fitness. We have recently identified a functional link between reproduction and lysosomal pH in somatic cells that provides a plausible model to explain how C. elegans integrates signals from the gonad to delay aging via improved proteolysis: in animals that have ceased reproduction, lysosomal-mediated proteolysis in the soma collapses and tissue deterioration ensues. The overarching goal of this research is to understand the genetic mechanisms that connect life history traits, such as reproduction and aging. Specifically, the proposed research aims to dissect the genes necessary to regulate lysosomal function, and consequently protein homeostasis, as animals age. In Objective 1, we will extend our efforts to isolate and characterize the genes required to trigger gonad-to-soma signaling at the transition between reproductive and non-reproductive periods through genome-wide genetic screens. We will use our expertise in developing transgenic sensors and pH-sensitive assays to detect dynamic changes in lysosomal pH in intestine and muscle of live worms as a phenotypic readout for these experiments. In Objective 2, we will address the chemical composition of intestinal cells that are influenced by signaling from the gonad following the end of reproduction. We will take a spectroscopic approach to quantitatively measure endogenous changes in the molecular signatures of live intestinal cells using Fourier-Transform Infrared Spectroscopy (FTIR) analysis. This work will take advantage of our previous experience in Mid-IR imaging of live C. elegans oocytes at the Canadian Light Source (CLS) and is expected to generate a detailed chemical map of aging-associated markers. Finally, in Objective 3, we will investigate the specific impact of lysosomal function in aging by using transgenic interventions to control lysosomal pH, followed by lifespan analyses. To this end, we will use transgenic and optogenetic tools that allow for in vivo vesicle acidification. In summary, these experiments will reveal novel genes that integrate reproductive information to modulate aging. Considering the evolutionary conservation of aging networks, we expect this research to be relevant to vertebrate systems as well.

在真核生物中，生殖和衰老是相互关联的过程。在不同的物种中，衰老与生殖周期同步，因此后代与动物最健康的时候重合。线虫中阻止生殖细胞增殖的突变也可以延长寿命，这表明性腺和体体之间存在基因调控的串扰，从而影响健康。这种跨组织信号如何在生殖周期中发挥作用，以及它在体细胞中通过哪些细胞过程发挥作用，目前尚不清楚。我的研究小组正在研究生殖和身体健康之间同步性的分子基础。我们最近在体细胞中发现了生殖和溶酶体pH之间的功能联系，这提供了一个可信的模型来解释线虫是如何整合来自性腺的信号，通过改善蛋白质分解来延缓衰老：在已经停止繁殖的动物中，溶酶体介导的蛋白质分解在胞体崩溃和组织退化随之而来。这项研究的首要目标是了解连接生活史特征的遗传机制，如生殖和衰老。具体地说，这项拟议的研究旨在剖析随着动物年龄的增长，调节溶酶体功能，从而调节蛋白质动态平衡所必需的基因。在目标1中，我们将继续努力，通过全基因组的遗传筛选，分离和鉴定在生殖期和非生殖期之间触发性腺到胞体信号转导所需的基因。我们将利用我们在开发转基因传感器和pH敏感分析方面的专业知识来检测活虫肠道和肌肉中溶酶体pH的动态变化，作为这些实验的表型读数。在目标2中，我们将讨论在生殖结束后受性腺信号影响的肠道细胞的化学成分。我们将采用光谱方法，使用傅立叶变换红外光谱(FTIR)分析来定量测量活的肠道细胞分子特征的内源性变化。这项工作将利用我们之前在加拿大光源(CLS)对线虫活卵母细胞进行中红外成像的经验，并有望生成与衰老相关的标记的详细化学地图。最后，在目标3中，我们将通过使用转基因干预来控制溶酶体的pH来研究溶酶体功能在衰老中的具体影响，然后进行寿命分析。为此，我们将使用转基因和光遗传工具，允许体内囊泡酸化。总而言之，这些实验将揭示整合生殖信息来调节衰老的新基因。考虑到衰老网络的进化保守性，我们预计这项研究也将与脊椎动物系统相关。