Estrogen receptor beta is expressed in human embryonic brain cells and is regulated by 17β-estradiol

In order to study estrogen effects on developing human neurons, we have established primary cultures of neurons and glia from 8-13-week human embryo cortex and spinal cord. The neuronal identity of the cultures was verified using the neuronal synaptic vesicle and neuronal endosomal membrane markers synaptotagmin, synapsin and synaptophysin, and the glial contribution to the mixed glial-neuronal cultures was verified using the glial marker glial fibrillary acidic protein (GFAP), We here report expression of estrogen receptor beta (ERβ) in these cells using RT-PCR and sequencing, RNAse protection assay, immunohistochemistry and immunoblotting. We found that both neuronal and mixed glial-neuronal cultures expressed ERβ, Treatment with 17β-estradiol gave an increased expression of ERβ in both types of cultures. These results suggest that ERβ is expressed in fetal brain and thus may mediate effects of estrogen in the developing nervous system. Furthermore, the results suggest that expression of ERβ in fetal brain may be regulated by estrogen.