Progesterone and the spinal cord: good friends in bad times.

In recent years, a growing list of publications point to the value of steroid hormones as an interesting option for the treatment of several type of lesions and diseases of the nervous system. Progesterone, well known for its role in pregnancy, has recently been shown to exert neuroprotective and promyelinating effects in both, the peripheral and central nervous system, including the injured spinal cord. Previous work from our laboratory has shown that progesterone actions in experimental models of spinal neurodegeneration or injury may involve the modulation of brain-derived neurotrophic factor, a neurotrophin with important implications in neuronal survival and axonal regeneration. The spinal cord is target for progesterone since neurons and glial cells express the intracellular receptors for this neuroactive steroid. However, the presence in the spinal cord of new membrane receptors and the enzymes involved in progesterone metabolism to its reduced derivatives, which modulate the activity of neurotransmitter receptors, suggest that progesterone actions involve pleiotropic mechanisms. Our recent data uncovering several molecular events may help to understand the protective and promyelinating actions of progesterone and further support the role of this steroid as a promising therapeutic agent for neurotrauma and/or neurodegenerative diseases.