Quantitative assessment of changes in cell growth, size and morphology during telomere-initiated cellular senescence in Saccharomyces cerevisiae.
Quantitative assessment of changes in cell growth, size and morphology during telomere-initiated cellular senescence in Saccharomyces cerevisiae.
复制标题
定量评估酿酒酵母端粒引发的细胞衰老过程中细胞生长、大小和形态的变化。
DOI：
10.1016/j.yexcr.2019.05.005
复制
发表时间：
2019
影响因子：
3.7
通讯作者：
Lewis,LKevin
中科院分区：
文献类型：
--
作者：
Ghanem,NedaZ;Malla,ShubhaRL;Araki,Naoko;Lewis,LKevin
芽殖酵母的端粒酶缺陷细胞。在培养的人成纤维细胞中，端粒经历进行性缩短和衰老。细胞表现出DNA损伤检查点样的应激反应，经历大小和形态的变化，并最终停止分裂。在这项研究中，一种新的检测方法，允许定量衰老的端粒酶缺陷test2细胞与应用统计。新技术的应用表明，在具有同源重组基因RAD 51、RAD 52或RAD 54共失活的突变体中，衰老被强烈加速，但当RAD 55、RAD 57或RAD 59被敲除时，衰老仅受到适度影响。此外，一种新的计算群体繁殖力的方法表明，est2细胞在大约64代后就丧失了生长能力，而est2 rad52细胞仅在42代后就丧失了生长能力。相差显微镜实验表明，senescingest2细胞以时间依赖性的方式变大，最终表现出60%的细胞大小增加。还观察到物理性质的逐渐改变，包括光散射特性和细胞沉降速率的显著变化。本文所述的结果将有助于未来的研究遗传和环境因素，影响端粒缩短相关的细胞衰老率使用酵母模型系统。
Telomerase-deficient cells of the budding yeastS. cerevisiaeexperience progressive telomere shortening and undergo senescence in a manner similar to that seen in cultured human fibroblasts. The cells exhibit a DNA damage checkpoint-like stress response, undergo changes in size and morphology, and eventually stop dividing. In this study, a new assay is described that allowed quantitation of senescence in telomerase-deficientest2cells with applied statistics. Use of the new technique revealed that senescence was strongly accelerated inest2mutants that had homologous recombination genes RAD51,RAD52orRAD54co-inactivated, but was only modestly affected whenRAD55,RAD57orRAD59were knocked out. Additionally, a new approach for calculating population doublings indicated that loss of growth capacity occurred after approximately 64 generations inest2cells but only 42 generations inest2 rad52cells. Phase contrast microscopy experiments demonstrated that senescingest2cells became enlarged in a time-dependent manner, ultimately exhibiting a 60% increase in cell size. Progressive alterations in physical properties were also observed, including striking changes in light scattering characteristics and cellular sedimentation rates. The results described herein will facilitate future studies of genetic and environmental factors that affect telomere shortening-associated cell senescence rates using the yeast model system.