Editors' ChoiceAging

Better Without Bax?

See allHide authors and affiliations

Science's STKE  27 Mar 2007:
Vol. 2007, Issue 379, pp. tw98
DOI: 10.1126/stke.3792007tw98

At about age 50, depletion of ovarian follicles through apoptosis leads to the loss of cyclic ovarian function in women. Menopause, in turn, is believed to set the stage for various health problems. Although aging female mice do not undergo menopause, they experience depletion of ovarian follicles and health complications similar to those of postmenopausal women. Perez et al., a research group that previously showed that oocyte loss was mitigated in mice without the proapoptotic Bax, investigated the effects of Bax knockout on the health of aging female mice. Aging Bax knockout female mice (KOs) were leaner and more active than their wild-type counterparts; they retained more of their hair, developed fewer cataracts, experienced less skin wrinkling, and had stronger bones. Behavioral analyses indicated that aging KOs were less anxious than wild-type mice and had improved attention but poorer contextual memory. Whereas young KOs were less likely to become pregnant than wild-type mice, somewhat older KOs were more likely to do so. Although aged KOs failed to become pregnant, they ovulated in response to gonadotropin treatment and, when their ovarian tissue was grafted into young wild-type females, the oocytes produced viable pups. Aged KOs had reduced concentrations of serum follicle-stimulating hormone compared to wild-type mice but similar concentrations of circulating estradiol. Ovariectomy experiments indicated that the effects of Bax deficiency on bone involved both ovary-dependent and -independent mechanisms. The authors concluded that preserving ovarian function might improve quality of life in aging women.

G. I. Perez, A. Jurisicova, L. Wise, T. Lipina, M. Kanisek, A. Bechard, Y. Takai, P. Hunt, J. Roder, M. Grynpas, J. L. Tilly, Absence of the proapoptotic Bax protein extends fertility and alleviates age-related health complications in female mice. Proc. Natl. Acad. Sci. U.S.A. 104, 5229-5234 (2007). [Abstract] [Full Text]

Stay Connected to Science Signaling