Glial expression of estrogen and androgen receptors after rat brain injury.
Estrogens and androgens can protect neurons from death caused by injury to the central nervous system. Astrocytes and microglia are major players in events triggered by neural lesions. To determine whether glia are direct targets of estrogens or androgens after neural insults, steroid receptor expression in glial cells was assessed in two different lesion models. An excitotoxic injury to the hippocampus or a stab wound to the parietal cortex and hippocampus was performed in male rats, and the resultant expression of steroid receptors in glial cells was assessed using double-label immunohistochemistry. Both lesions induced the expression of estrogen receptors (ERs) and androgen receptors (ARs) in glial cells. ERalpha was expressed in astrocytes immunoreactive (ERalpha-ir) for glial fibrillary acidic protein or vimentin. AR immunoreactivity colocalized with microglial markers, such as Griffonia simplicifolia lectin-1 or OX-6. The time course of ER and AR expression in glia was studied in the stab wound model. ERalpha-ir astrocytes and AR-ir microglia were observed 3 days after lesion. The number of ERalpha-ir and AR-ir glial cells reached a maximum 7 days after lesion and returned to low levels by 28 days postinjury. The studies of ERbeta expression in glia were inconclusive; different results were obtained with different antibodies. In sum, these results suggest that reactive astrocytes and reactive microglia are a direct target for estrogens and androgens, respectively.
García-Ovejero
Daniel
D
Instituto Cajal, Consejo Superior de Investigaciones Científicas, 28002 Madrid, Spain.
Veiga
Sergio
S
García-Segura
Luis Miguel
LM
Doncarlos
Lydia L
LL
D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000378:metabolism; D001921:Brain / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D001930:Brain Injuries / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D004195:Disease Models, Animal; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D005911:Gliosis / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D007150:Immunohistochemistry; D007608:Kainic Acid; D037102:Lectins / Q000378:metabolism; D008297:Male; D017628:Microglia / Q000166:cytology / Q000378:metabolism; D009410:Nerve Degeneration / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D009416:Nerve Regeneration / Q000502:physiology*; D009457:Neuroglia / Q000378:metabolism*; D037121:Plant Lectins; D051381:Rats; D017208:Rats, Wistar / Q000254:growth & development* / Q000293:injuries / Q000378:metabolism; D011944:Receptors, Androgen / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism*; D014746:Vimentin / Q000378:metabolism
D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D005904:Glial Fibrillary Acidic Protein; C045475:Griffonia simplicifolia lectins; D037102:Lectins; D037121:Plant Lectins; D011944:Receptors, Androgen; D011960:Receptors, Estrogen; D014746:Vimentin; D007608:Kainic Acid