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Cell competition, aneuploidy, and aging

细胞竞争、非整倍性和衰老

基本信息

批准号：
10648670
负责人：
Nicholas E Baker
金额：
$ 26.06万
依托单位：
ALBERT EINSTEIN COLLEGE OF MEDICINE
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：
2023-05-01 至 2025-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10648670
关键词：
Address Adult Affect Age Aging Alleles Amino Acid Substitution Aneuploid Cells Aneuploidy Animal Experiments Behavioral Biological Assay Brain Bypass CDKN2A gene Cell Aging Cell Cycle Arrest Cell Nucleus Cell Survival Cells Chromosome Mapping Chromosome Segregation Chromosomes Custom DNA DNA Damage Deterioration Development Diploidy Disease Drosophila genus Drosophila melanogaster Elderly Embryo Failure Fluorescent in Situ Hybridization Frequencies Functional disorder Gamma-H2AX Gene Dosage Gene Proteins Genes Genetic Screening Genome Genome Stability HMGB Family Gene Heart Homeodomain Proteins Incidence Inflammatory Interphase LMNB1 gene Liver Longitudinal Studies Mammals Measures Metabolic Monitor Mus Mutant Strains Mice Mutation Nuclear Organ Pathway interactions Phenotype Phosphotransferases Play Ploidies Postpartum Period Process Property Rejuvenation Research Ribosomal Proteins Risk Factors Role Route Siblings Signal Transduction Testing Tissues Tomatoes age related aged beta-Galactosidase cell injury chromosome number abnormality detection method genome-wide health assessment healthspan healthy aging improved mosaic mouse model mutant novel p53-binding protein 1 prevent response senescence sensor

项目摘要

Project Summary/Abstract Aging, the progressive deterioration of tissue and organ function, is the largest risk factor for developing disease. Increasing evidence points to the accumulation of damaged cell cycle-arrested cells with age (cellular senescence) as a cause for the development of certain aging-associated diseases. Clearance of senescent cells results in improvement in age-related phenotypes. Accordingly, limiting the emergence of senescent cells is expected to mitigate age-related phenotypes. Recent studies, including our own, point to aneuploidy, an abnormal chromosome number, as a feature of senescent cells. Our recent studies in Drosophila melanogaster demonstrate that cell competition, the elimination of cells based on their difference from other neighboring cells rather than their intrinsic properties, is a means for removing aneuploid cells because of copy number changes in Ribosomal protein (Rp) genes. In particular, cell competition that eliminates aneuploid cells is anticipated to prevent the accumulation of senescent cells. The 80 eukaryotic Rp genes map across the entire chromosome complement, thus aneuploidy or other large- scale genome changes almost always affect their copy number making cell competition based on Rp gene dosage a strategic mode to recognize and eliminate aneuploid cells. A specific mutation affecting RpS12 in Drosophila prevents the elimination of Rp+/- cells by cell competition, and permits greater survival of aneuploid cells in Drosophila. We will test whether a homologous process affects incidence of aneuploidy and aging phenotypes in a novel mouse model, Rps12 mutant mouse strains, and an aneuploidy induced mouse model whereby aneuploidy is induced by reduced expression of Bub1, an essential kinase for proper chromosome segregation. In Aim 1 we will Determine whether Rps12D90/D90 mice accumulate aneuploid cells, focusing on the cortex. Prior studies establish that aneuploidy is prominent in the embryonic cortex but decreases significantly in frequency by 4-month post-partum, consistent with loss of aneuploid cells during this period. Using custom developed assays for the quantification of aneuploidy in single cells we will measure aneuploid cell frequencies at E13.5 and at 4 months post-partum in RpS12 mutant cortex and in wild type cortex from sibling controls. These assays will establish whether RpS12 plays a conserved role in recognizing and eliminating spontaneous aneuploid cells in mouse cortex. In Aim 2 we will lineage-trace aneuploid cells to determine whether Rps12D90/D90 mice are defective for eliminating aneuploid cells. Conditional reduction in Bub1 expression driven by Homeobox protein 1 -Emx1-Cre will generate clones of Bub1 defective aneuploid cells that will be identified, in the ROSAnT-nG lineage-tracing background, as cells expressing EGFP rather than tdTomato. FACS analysis of isolated nuclei from whole brain will provide EGFP/tdTomato ratios to specifically address roles of RpS12 in aneuploid cell survival or elimination. Lastly, in Aim 3 we will perform a longitudinal study to assess the health of aging Rps12D90/D90 mice. Assays for physical, behavioral, metabolic, and inflammatory deterioration that mark aging will be performed on young (6 months) and aged (22 months old) Rps12D90/D90 mice in comparison with matched controls to assess aging. Globally, these studies represent a first exploration in mammals of the hypothesis that cell competition can prevent the accumulation of senescent cell by eliminating those aneuploid cells that reduce Rp gene copy number, as is the case in Drosophila and will determine if the role of RpS12 in this process is conserved and can be exploited as a potential route to rejuvenation.

项目总结/摘要衰老，即组织和器官功能的逐渐恶化，是最大的风险因素，发展疾病。越来越多的证据表明，受损的细胞周期停滞细胞的积累，年龄（细胞衰老）是某些与衰老有关的疾病发展的原因。间隙衰老细胞的衰老导致与年龄相关的表型的改善。因此，限制预期衰老细胞减轻年龄相关的表型。最近的研究，包括我们自己的研究，指出非整倍性，一种异常的染色体数目，作为衰老细胞的特征。我们最近对果蝇的研究表明，细胞竞争，基于细胞与其他相邻细胞的差异，而不是其内在属性，是一种手段用于去除非整倍体细胞，因为核糖体蛋白（Rp）基因的拷贝数变化。特别是，预期消除非整倍体细胞的细胞竞争可防止衰老细胞的积累。 80个真核细胞Rp基因在整个染色体上分布，因此是非整倍体或其他大的染色体。大规模的基因组变化几乎总是影响它们的拷贝数，使得基于Rp基因的细胞竞争剂量是识别和消除非整倍体细胞的策略模式。一种影响RpS 12的特异性突变，果蝇通过细胞竞争阻止Rp+/-细胞的消除，并允许非整倍体的更大存活果蝇的细胞我们将测试同源过程是否影响非整倍体和衰老的发生率新型小鼠模型、Rps 12突变小鼠品系和非整倍体诱导小鼠模型中的表型由此通过Bub 1（一种正常染色体必需激酶）的表达减少来诱导非整倍性隔离。在目标1中，我们将确定Rps 12 D90/D90小鼠是否积累非整倍体细胞，重点是皮层先前的研究证实，非整倍体在胚胎皮层中很突出，但在胚胎皮层中显著减少。在产后4个月的频率，与非整倍体细胞在此期间的损失一致。使用自定义我们开发了用于定量单细胞中非整倍体的测定法，在E13.5和产后4个月，RpS 12突变体皮质和来自同胞的野生型皮质中的频率对照这些试验将确定RpS 12是否在识别和消除小鼠皮层自发非整倍体细胞。在目标2中，我们将谱系追踪非整倍体细胞以确定 Rps 12 D90/D90小鼠是否有消除非整倍体细胞的缺陷。Bub 1中的条件还原由同源框蛋白1 -Emx 1-Cre驱动的表达将产生Bub 1缺陷型非整倍体细胞的克隆在ROSAnT-nG谱系追踪背景下，将被鉴定为表达EGFP而不是 tdTomato从全脑分离的细胞核的FACS分析将提供EGFP/tdTomato比率，以特异性地解决RpS 12在非整倍体细胞存活或消除中的作用。最后，在目标3中，我们将执行纵向研究评估衰老Rps 12 D90/D90小鼠的健康。对身体、行为、代谢和将对年轻人（6个月）和老年人（22个月大）进行标记老化炎性恶化 Rps 12 D90/D90小鼠与匹配对照比较以评估衰老。在全球范围内，这些研究代表了对哺乳动物细胞竞争假说的首次探索，可以通过消除那些减少Rp基因拷贝的非整倍体细胞来防止衰老细胞的积累，数字，就像果蝇的情况一样，并将决定RpS 12在这一过程中的作用是否保守，可以作为一种潜在的返老还童途径。