Mechanism of in-vitro aging

体外老化机制

基本信息

批准号：
7258321
负责人：
Lysle Kevin Lewis
金额：
$ 17.87万
依托单位：
TEXAS STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-04-01 至 2011-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7258321
关键词：
Acetylcysteine Affect Age Aging Antioxidants Back Biochemical Biological Assay Bleomycin Bypass Cadmium Cell Aging Cell Cycle Cell Cycle Arrest Cell Death Cell model Cells Cessation of life Chemicals Chromosomal Instability Chromosome abnormality Chromosomes Chronic Class Complement Condition Cultured Cells DNA DNA Maintenance DNA Sequence Rearrangement DNA biosynthesis DNA damage checkpoint DNA lesion Defect Diploid Cells Diploidy Disease Dose EUK-134 Elevation Environment Environmental Risk Factor Enzymes Eukaryota Eukaryotic Cell Event Excision Exhibits Exonuclease Fibroblasts Free Radicals Frequencies G2 Phase Gel Generations Genes Genetic Genetic Recombination Growth Haploid Cells Haploidy Human Hydrogen Peroxide In Vitro Individual Iron Kinetics Kinetochores Lead Length Libraries Link Malignant Neoplasms Mammalian Cell Mating Types Mediating Metabolic Modeling Molecular Monitor Partner in relationship Phenotype Physiologic pulse Plasmids Ploidies Polymerase Process Production Protein Overexpression Proteins Pulse taking Rate Reaction Reactive Oxygen Species Regulator Genes Research Resected Resistance Resveratrol Roentgen Rays Role SOD2 gene Saccharomyces cerevisiae Saccharomycetales Sister Chromatid Superoxide Dismutase System Techniques Telomerase Telomere Recombination Telomere Shortening Testing Time Vitamin K 3 Week Yeasts catalase cell age chemical genetics chromosome loss experience genetic analysis glutathione peroxidase glutathione peroxidase GPX1 human tissue in vivo mimetics mutant normal aging novel strategies nuclease oxidation oxidative DNA damage research study senescence size spleen exonuclease telomere

项目摘要

DESCRIPTION (provided by applicant): Most human cells halt production of the enzyme telomerase shortly after differentiation and subsequently experience progressive shortening of chromosome ends, called telomeres. Telomere loss and several other changes seen during normal aging in vivo are also observed in primary human cells grown in culture, which stop dividing after approximately 50 cell cycles (called replicative senescence). Telomerase-deficient cells of the model eukaryote Saccharomyces cerevisiae (budding yeast) also exhibit telomere-shortening and senescence. The precise cause of senescence is unknown, but evidence suggests that exonuclease resection of the shortened telomeres leads to chromosome instability. This instability is characterized by chromosome loss and deletion events, as well as rearrangements leading to dicentric fusions and other aberrations. Aim 1: A new, regulatable telomerase expression system will be used to test proposed mechanisms of cell senescence. The lethal chromosome rearrangement model will be critically tested by asking if cells that stop growing in late senescence can be rescued by reactivation of telomerase. Experiments will also analyze mutants defective in (a) kinetochore functions that stabilize dicentrics, (b) DNA damage checkpoint responses, and (c) exonuclease-resection of telomeres. Frequencies of chromosome aberrations and telomere lengths in the rescued cells will be assessed. Aim 2: The ability of normal, checkpoint-, and resection-defective haploid cells at "the brink of death" to be rescued by mating to undamaged cells, forming diploids with shortened chromosomes complemented by good copies, will be assayed. Frequencies of aberrations in the stabilized diploids will be monitored. Aim 3: The impact of well-characterized chemical pro-oxidants and antioxidants on senescence will be determined. Survival and telomere integrity will also be monitored in cells in which genes required for resistance to oxidative DNA damage have been inactivated. Aim 4: A new approach to characterization of senescence bypass mechanisms will be employed that involves identification of high copy suppressors of in vitro cell aging. Chromosome shortening and many other metabolic changes occur during both normal human aging and also in cells grown in culture. The proposed experiments will identify genetic and environmental factors that modulate cellular aging that may also function in vivo. Chromosomes become progressively shortened in cells of most human tissues during aging, with subsequent DNA instability linked to increases in cancer and age-associated diseases. The proposed research will enhance our understanding of events that occur as a consequence of shortened chromosomes and factors that affect the rate of shortening.

描述（由申请人提供）：大多数人类细胞在分化后不久就停止了酶端粒酶的产生，随后会逐渐缩短染色体末端，称为端粒。在培养物中生长的原代人细胞中也观察到端粒损失和在正常衰老期间发生的其他几种变化，在大约50个细胞周期后停止分裂（称为复制衰老）。酿酒酵母（芽酵母）模型的端粒酶缺陷细胞也表现出端粒变形和衰老。衰老的确切原因尚不清楚，但有证据表明，缩短端粒的外切除酶切除会导致染色体不稳定性。这种不稳定性的特征是染色体丢失和缺失事件，以及重新排列，导致二含融合和其他畸变。 AIM 1：一种新的可调节端粒酶表达系统将用于测试提出的细胞衰老机制。致命的染色体重排模型将通过询问在晚期衰老中停止生长的细胞是否可以通过端粒酶的重新激活来挽救。实验还将分析（a）稳定双齿的动力学函数中有缺陷的突变体，（b）DNA损伤检查点响应以及（c）端粒的核酸外切酶切除。将评估救出细胞中染色体畸变和端粒长度的频率。 AIM 2：将分析正常，检查点和切除缺陷型单倍体细胞在“死亡的边缘”中通过交配与未损坏的细胞挽救的能力，将分析用缩短的染色体形成替代良好副本的二倍体。将监测稳定二倍体中像差的频率。 AIM 3：将确定良好的化学促氧化剂和抗氧化剂对衰老的影响。在细胞中还将监测生存和端粒完整性，在这种细胞中，抗氧化DNA损伤所需的基因已被灭活。 AIM 4：将采用一种新的衰老旁路机制表征方法，涉及鉴定体外细胞衰老的高拷贝抑制剂。染色体缩短和许多其他代谢变化在正常的人类衰老和培养物中生长的细胞中发生。提出的实验将确定调节细胞衰老的遗传和环境因素，这些因素也可能在体内发挥作用。在衰老期间，大多数人体组织细胞中染色体逐渐缩短，随后的DNA不稳定性与癌症和年龄相关疾病的增加有关。拟议的研究将增强我们对由于缩短染色体和影响缩短速率的因素而发生的事件的理解。

项目成果

期刊论文数量（9）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Analysis of oligonucleotide DNA binding and sedimentation properties of montmorillonite clay using ultraviolet light spectroscopy.

DOI：
10.1021/bm800970v
发表时间：
2009-01-12
期刊：
BIOMACROMOLECULES
影响因子：
6.2
作者：
Beall, Gary W.;Sowersby, Drew S.;Roberts, Rachel D.;Robson, Michael H.;Lewis, L. Kevin
通讯作者：
Lewis, L. Kevin

Inhibition of DNA double-strand break repair by the Ku heterodimer in mrx mutants of Saccharomyces cerevisiae.

DOI：
10.1016/j.dnarep.2008.09.010
发表时间：
2009-02-01
期刊：
DNA repair
影响因子：
3.8
作者：
Wasko BM;Holland CL;Resnick MA;Lewis LK
通讯作者：
Lewis LK

Blunt-ended DNA double-strand breaks induced by endonucleases PvuII and EcoRV are poor substrates for repair in Saccharomyces cerevisiae.

由核酸内切酶 PvuII 和 EcoRV 诱导的平端 DNA 双链断裂是酿酒酵母修复的不良底物。

DOI：
10.1016/j.dnarep.2010.02.008
发表时间：
2010
期刊：
DNA repair
影响因子：
3.8
作者：
Westmoreland,JamesW;Summers,JenniferA;Holland,CoryL;Resnick,MichaelA;Lewis,LKevin
通讯作者：
Lewis,LKevin

Charge density and particle size effects on oligonucleotide and plasmid DNA binding to nanosized hydrotalcite.