Sirt1, notch and stem cell age asymmetry

Almost all complex multicellular organisms on earth utilize oxygen for the production of energy. This strategy carries the risk for damaging ROS to be generated and so these biochemical pathways must be highly regulated. Because of this, regulation of oxidative-phosphorylation is tightly coordinated with every aspect of cellular physiology, including stem cell regulation during embryonic development and in adult organisms. The protein-deacetylase, SIRT1, has received much attention because of its roles in oxygen metabolism, cellular stress response, aging, and has been investigated in various species and cell types including embryonic stem cells. However, there is a dearth of information on SIRT1 in adult stem cells, which have a pivotal role in adult aging processes. Here, we discuss the potential relationships between SIRT1 and the surface receptor protein, Notch, with stem cell self-renewal, asymmetric cell division, signaling and stem cell aging.