Distribution of estrogen receptor α and β in the mouse central nervous system: In vivo autoradiographic and immunocytochemical analyses

Abstract

Although the distribution of estrogen receptor beta (ERbeta) immunoreactivity in the rat central nervous has been reported, no such data are available in the mouse. The present study used in vivo autoradiography utilizing a (125)I-estrogen that has equal binding affinity for both receptors as well as immunohistochemistry for ERbeta and ERalpha, to investigate and compare the distribution of the two ERs in the mouse CNS. The use specific antisera against ERalpha and ERbeta allowed us to evaluate the contribution of these receptors to the binding detected with autoradiography. In addition, data were collected in ovariectomized wildtype and ERalpha KO (knockout) mice to examine developmental regulation of ERbeta expression by ERalpha. These studies revealed that in the mouse CNS, combining immunoreactivity for ERalpha with that for ERbeta accounted for all regions where binding was seen using autoradiography. Therefore, these data strongly suggest that the major contributors of estrogen binding in the mouse CNS are ERalpha and ERbeta. Together, these data provide an anatomical foundation for future studies and advance our understanding of estrogen action in the CNS. Moreover, since the immunocytochemical images were similar in wildtype and ERalpha KO mice, these studies suggest that the lack of ERalpha does not influence the expression of ERbeta in the central nervous system.

Differential Expression of Estrogen Receptors in Two Hippocampal Regions During the Estrous Cycle of the Rat

“…Several areas of the brain present one or the other subtype or overlapping patterns of both ERa and ERb Ravizza et al, 2002;Matthews and Gustafsson, 2003;Merchenthaler et al, 2004;Barha and Galea, 2011).…”

Soy, phytoestrogens and their impact on reproductive health

“…et al, 1998). The fact that ERa and b display overlapping but distinct expression patterns in the male and female reproductive systems and throughout development (Matthews and Gustafsson, 2003;Meltser et al, 2008;Merchenthaler et al, 2004) may explain why phytoestrogens do not act as classical estrogen agonists. The estrogenic activity of isoflavones may in fact depend of the presence and/ or recruitment of co-activator or co-repressor proteins present in particular cell types or tissues at specific times of development.…”

Estrogen anti-inflammatory activity in brain: A therapeutic opportunity for menopause and neurodegenerative diseases

“…Using ER-null mice several reports described the selective involvement of ERa in the anti-inflammatory and neuroprotective activity of estradiol against neuroinflammatory and vascular pathologies of the brain ( [62,80,185,242]). Despite the fact that ERb has been shown to be expressed widely in the CNS in adult mice ( [161,167]), it appears that this receptor isoform is not involved in mediating the protective effect of estrogens in neuroinflammatory diseases. Yet, both ERa and ERb are involved in the control of inflammation by estradiol, depending on the tissue involved and on the signal utilized [88].…”