Department of Cell and Developmental Biology; Department of Microbiology and Physiological Systems
Cell Biology | Medical Cell Biology
The age-dependent decline in the self-renewal capacity of stem cells plays a critical role in aging, but the precise mechanisms underlying this decline are not well understood. By limiting proliferative capacity, senescence is thought to play an important role in age-dependent decline of stem cell self-renewal, although direct evidence supporting this hypothesis is largely lacking. We have previously identified the E3 ubiquitin ligase Smurf2 as a critical regulator of senescence. In this study, we found that mice deficient in Smurf2 had an expanded hematopoietic stem cell (HSC) compartment in bone marrow under normal homeostatic conditions, and this expansion was associated with enhanced proliferation and reduced quiescence of HSCs. Surprisingly, increased cycling and reduced quiescence of HSCs in Smurf2-deficient mice did not lead to premature exhaustion of stem cells. Instead, HSCs in aged Smurf2-deficient mice had a significantly better repopulating capacity than aged wild-type HSCs, suggesting that decline in HSC function with age is Smurf2 dependent. Furthermore, Smurf2-deficient HSCs exhibited elevated long-term self-renewal capacity and diminished exhaustion in serial transplantation. As we found that the expression of Smurf2 was increased with age and in response to regenerative stress during serial transplantation, our findings suggest that Smurf2 plays an important role in regulating HSC self-renewal and aging.
aging, hematopoietic stem cells, self-renewal, senescence, Smurf2
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© 2014 The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
DOI of Published Version
Ramkumar, C., Kong, Y., Trabucco, S. E., Gerstein, R. M. and Zhang, H. (2014), Smurf2 regulates hematopoietic stem cell self-renewal and aging. Aging Cell. doi: 10.1111/acel.12195
Ramkumar, Charusheila; Kong, Yahui; Trabucco, Sally E.; Gerstein, Rachel M.; and Zhang, Hong, "Smurf2 regulates hematopoietic stem cell self-renewal and aging" (2014). GSBS Student Publications. 1848.