Regulation of Lipids is Central to Replicative Senescence

Cellular replicative senescence, a state of permanent cell-cycle arrest that occurs following an extended period of cell division in culture, has been linked to organismal aging, tissue repair and tumorigenesis. In this study, we comparatively investigated the global lipid profiles and mRNA content of proliferating and senescent-state BJ fibroblast cells. We found that both the expression levels of lipid-regulating genes, as well as the abundance of specific lipid families, are actively regulated. We further found that 19 polyunsaturated triacylglycerol species showed the most prominent changes during replicative senescence. We argue that diversion of polyunsaturated fatty acids to glycerolipid biosynthesis could be responsible for the accumulation of specific triacylglycerols. This, in turn, could be one of the cellular mechanisms to prevent lipotoxicity under increased oxidative stress conditions observed during replicative senescence. Collectively, our results place regulation of specific lipid species to a central role during replicative senescence. Overall design: We sequence total RNA from 3 early PD and 3 senesent human BJ cell lines to detect the expressional differences between early PD and senescent cells.

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Lizardo DY, Lin YL, Gokcumen O, Atilla-Gokcumen GE