Department of Pathology, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK.
Biogerontology. 2009 Dec;10(6):683-93. doi: 10.1007/s10522-009-9216-4.
The replicative lifespan of many cell types is determined by the length of telomeres in the initiating cell population. In 20% oxygen, IMR90 cells have a shorter replicative lifespan compared to that achieved in conditions that lower the levels of oxidative stress. We sought to address the role of telomere dynamics in determining the replicative lifespan of IMR90 cells. We analysed clonal populations cultured in parallel in 3 and 20% oxygen. We observed that, at senescence, telomere length was shorter in 3% oxygen and this was proportional to the lifespan extension. We observed no detectable difference in the rate of telomere erosion in the two culture conditions, however as the cells approached senescence the growth rate of the cultures slowed with a commensurate increase in the rate of telomere erosion. We conclude that, in 20% oxygen senescence of IMR90 is telomere-independent, but telomere-dependent in 3% oxygen.
许多细胞类型的复制寿命取决于起始细胞群体中端粒的长度。在 20%氧气中，与降低氧化应激水平的条件相比，IMR90 细胞的复制寿命更短。我们试图确定端粒动力学在决定 IMR90 细胞复制寿命中的作用。我们分析了在 3%和 20%氧气中平行培养的克隆群体。我们观察到，在衰老时，3%氧气中端粒长度较短，这与寿命延长成正比。然而，在两种培养条件下，端粒侵蚀的速度没有检测到明显的差异，但是随着细胞接近衰老，培养物的生长速度减慢，端粒侵蚀的速度相应增加。我们的结论是，在 20%氧气中，IMR90 的衰老与端粒无关，但在 3%氧气中，衰老与端粒有关。
