Female Stem Cells Regenerate Muscle Better than Male
BY LAUREN UZDIENSKI, APRIL 11, 2007
New research out of the University of Pittsburgh Medical Center show that female stem cells have an edge over male stem cells in regenerating muscle. Johnny Huard et al suggest in the Journal of Cell Biology that this research is among the first of its kind and should encourage other researchers to consider cell sex as a variable in studies.
Muscle-derived stem cells (MDSCs) have been shown to regenerate diseased muscle tissue when transplanted in mice. The new studies were designed to evaluate the variations in MDSCs based on regeneration index (RI), or how efficiently new muscle was created. RI correlated with cell sex, with male MDSCs showing a significantly lower RI than female MDSCs. Further testing indicated that the increased regeneration potential may be attributed to differences in the cells' stress responses - in a low oxygen environment, which would be expected following transplantation, male MDSCs more readily proliferate and may become depleted by the lack of oxygen. In contrast, female MDSCs maintain a low level of differentiation. Following this relatively sleepy state, female MDSCs begin to show increased proliferation three days after implantation.
As the role of stem cells in research and innovation grows, results like Dr. Huard's further and focus our understanding of stem cells. As the author notes, marking a jumping-off point for future research, "[evidence of cell sex differences] should influence how researchers report and investigate the use of progenitor cells for regenerative medicine."
