Sequestration and clearance of age-induced damage in gametogenesis

配子发生过程中年龄诱导损伤的隔离和清除

• 批准号: 9757589
• 负责人: Jay S Goodman
• 金额: $ 4.03万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-20 至 2021-07-19
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9757589
• 关键词: Address; Affect; Age; Aging; Animal Model; Apoptosis; Autophagocytosis; Biological Models; Caenorhabditis elegans; Candidate Disease Gene; Cell Aging; Cell Nucleolus; Cell Nucleus; Cell division; Cells; Chemicals; Complex; Coupled; Cytolysis; Cytoplasm; DNA; Data; Diploidy; Disease; Exclusion; Exhibits; Fluorescence; Functional disorder; Gametogenesis; Generations; Genes; Genetic; Genetic Recombination; Germ Cells; Haploidy; Inherited; Lead; Left; Longevity; Lysosomes; Mediating; Meiosis; Membrane Proteins; Microfluidics; Microscopic; Mitotic; Modeling; Molecular; Mothers; Mutation; Natural regeneration; Nature; Nuclear; Nuclear Envelope; Nuclear Pore; Nuclear Pore Complex; Nuclear Pore Complex Proteins; Nutrient; Organelles; Organism; Pathway interactions; Peptide Hydrolases; Process; Protease Inhibitor; Proteins; Quality Control; Refractory; Rejuvenation; Reporting; Reproduction spores; Research; Ribosomal DNA; Saccharomyces cerevisiae; Saccharomycetales; Site; Stem cells; System; Testing; Therapeutic; Ubiquitin; Vacuole; Yeasts; age related; aged; cell age; combat; daughter cell; experimental study; genetic approach; genetic manipulation; genetic pedigree; healthspan; improved; knock-down; live cell imaging; live cell microscopy; multicatalytic endopeptidase complex; mutant; precursor cell; programs; protein aggregate; protein aggregation; proteotoxicity; trait; yeast genetics

Organisms acquire damage as they age1, 2. Common traits that are associated in aged cells are the accumulation of protein aggregates, nucleolar abnormalities and dysfunctional organelles2, 3,5. However, it remains difficult to distinguish which traits directly promote cellular aging, versus those that arise as a consequence of aging. Generating a model system that addresses this issue will allow us to develop better therapeutic strategies to combat aging and improve health span. Similar to metazoans, budding yeast accumulates protein aggregates, nucleolar abnormalities and dysfunctional organelles during aging. Surprisingly, as aged yeast cells undergo gametogenesis, the resulting gametes no longer contain the age-associated traits6. Furthermore, the longevity of the gametes is restored by this process, suggesting that elimination of age-associated traits causes cellular rejuvenation6. I aim to dissect the molecular mechanisms that counteract age-induced damage during gametogenesis and test their impact on lifespan. The experiments in Aim 1 will determine which genes in budding yeast cause gametes to avoid the inheritance of age-associated traits. Analyses so far indicate that cellular contents subject to age-induced damage, including nuclear pore complexes, protein aggregates and the nucleoli, localize to a subcompartment of the nuclear envelope during gametogenesis. This compartment is not inherited by the gametes as they regenerate contents de novo 8, 12. These observations suggest that age-induced traits are associated with the nuclear envelope subcompartment via specific adaptors, which cause their exclusion from the gametes. If true, disruption of each candidate adaptor should lead to retention of a distinct type of age-induced damage. In parallel, an unbiased genetic approach will be taken to screen for mutants that pass on age-induced traits to their gametes30. Further assessment of each mutant by microfluidic pedigree analyses will reveal which traits are limiting for lifespan39. The experiments in Aim 2 will determine how long-lived proteins that accumulate in aged cells are destroyed during budding yeast and C.elegans gametogenesis. Budding yeast gametes do not inherit the vacuole of the progenitor cell, which is ultimately destroyed. When the vacuole lyses, it releases proteases that normally degrade long-lived proteins7, 13, 14. Therefore, inhibiting vacuolar proteases, as well as other factors associated with protein quality control may cause long-lived proteins found in aged cells to persist during gametogenesis. Similar phenomena have been recently reported in the C.elegans germline, which will additionally be explored17, 18. The results will be verified by yeast genetics, worm genetics and fluorescence live-cell imaging. Identifying the genes required to eliminate long-lived proteins will facilitate the generation of new strategies to remove proteotoxic damage.

生物体随着年龄的增长而受到损害1, 2。与衰老细胞相关的常见特征是 蛋白质聚集体的积累、核仁异常和功能失调的细胞器2, 3,5。然而，它 仍然很难区分哪些特征直接促进细胞衰老，哪些特征是作为细胞衰老而产生的 衰老的后果。生成一个解决这个问题的模型系统将使我们能够更好地开发 对抗衰老和改善健康寿命的治疗策略。 与后生动物类似，芽殖酵母积累蛋白质聚集物、核仁异常和 衰老过程中细胞器功能失调。令人惊讶的是，随着老化的酵母细胞经历配子发生，产生的 配子不再包含与年龄相关的特征6。此外，配子的寿命可以通过以下方式恢复： 这一过程表明，消除与年龄相关的特征会导致细胞再生6。我的目的是剖析 抵消配子发生过程中年龄引起的损伤的分子机制并测试其影响 关于寿命。 目标 1 中的实验将确定出芽酵母中的哪些基因导致配子避免 与年龄相关的特征的遗传。迄今为止的分析表明，细胞内容物受到年龄诱导的影响 损伤，包括核孔复合物、蛋白质聚集体和核仁，定位于子区室 配子发生过程中核膜的变化。这个隔间不是由配子继承的，因为它们 从头再生内容 8, 12。这些观察结果表明，年龄诱导的特征与 核膜亚区室通过特定的适配器，导致它们被排除在配子之外。如果属实的话， 每个候选适配器的破坏应该导致保留不同类型的年龄引起的损伤。在 与此同时，将采用公正的遗传方法来筛选能够将年龄诱导的特征传递给人类的突变体。 他们的配子30。通过微流体谱系分析对每个突变体进行进一步评估将揭示哪些特征 寿命受到限制39。 目标 2 中的实验将确定衰老细胞中积累的长寿蛋白质的寿命。 在芽殖酵母和线虫配子发生过程中被破坏。出芽酵母配子不遗传 祖细胞的液泡，最终被破坏。当液泡裂解时，它会释放蛋白酶 通常会降解长寿命蛋白质7,13,14。因此，抑制液泡蛋白酶以及其他因素 与蛋白质质量控​​制相关的可能会导致衰老细胞中发现的长寿命蛋白质在 配子发生。最近在秀丽隐杆线虫种系中也报道了类似的现象，这将 另外还有待探索17, 18。结果将通过酵母遗传学、蠕虫遗传学和荧光进行验证 活细胞成像。识别消除长寿命蛋白质所需的基因将有助于产生 消除蛋白毒性损伤的新策略。