Vasoactive intestinal peptide attenuates cytochrome c translocation, and apoptosis, in rat hippocampal stem cells.

While widely distributed in the brain, one area with concentrated levels of vasoactive intestinal peptide (VIP) is the hippocampus. In this study, rat hippocampal stem cells were used to examine VIP's effects on apoptotic cell death induced by withdrawal of trophic support. In the apoptotic cascade, the translocation of cytochrome c from the mitochondria to the cytoplasm activates caspases, resulting in cell death. VIP decreased this translocation of cytochrome c in a dose-dependent manner, and reduced apoptosis. This demonstrates that VIP regulates neuronal apoptosis and may contribute to stem cell homeostasis.