Progesterone, BDNF and neuroprotection in the injured CNS.

We investigated whether the neuroprotective mechanism of progesterone involves modulation of the neurotrophin brain-derived neurotrophic factor (BDNF). We show that BDNF expression is upregulated following cerebral ischemia in mice and in C6 glioma cells exposed to cytokines, while reduced in cerebellar granule neurons exposed to the excitotoxin glutamate. Progesterone was without additional effect on BDNF in these paradigms. Progesterone also protected PC12 neurons deprived of trophic support, while it decreased cerebellar granule neuron viability. Both the effects of progesterone and the expression of BDNF can clearly vary following stroke-like injuries, however we found no evidence for a neuroprotective relationship between progesterone and BDNF.