Dehydroepiandrosterone (DHEA) and its sulfated derivative (DHEAS) regulate apoptosis during neurogenesis by triggering the Akt signaling pathway in opposing ways

Dehydroepiandrosterone (DHEA) can function to protect neural precursors and their progeny targeted with toxic insults; however, the molecular mechanisms underlying the neuroprotective effects of DHEA are not understood. We cultured neural precursors from the embryonic forebrain of rats and examined the effects of DHEA and its sulfated derivative (DHEAS) on the activation of the serine-threonine protein kinase Akt, which is widely implicated in cell survival signaling. We found that DHEA activated Akt in neural precursor culture, in association with a decrease in apoptosis. In contrast, DHEAS decreased activated Akt levels and increased apoptosis. The effects of DHEA on neural cell survival and activation of Akt were not blocked by the steroid hormone antagonists flutamide and tamoxifen, but both were blocked by a PI3-K inhibitor, LY294002. These findings suggest that during neurogenesis in the developing cortex, DHEA and DHEAS regulate the survival of neural precursors and progeny through the Akt signaling pathway.