Purchase this article with an account.
J. M. Flynn, S. Dimitrijevich, M. Younes, G. Skliris, L. C. Murphy, P. R. Cammarata; Gender-Related Expression and Comparative Subcellular Localization of Estrogen Receptor Beta Isoforms in Cultured Normal Human Lens Epithelial Cells. Invest. Ophthalmol. Vis. Sci. 2007;48(13):2429.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Wild type estrogen receptor beta (wtER-ß1) and its splice variants (ER-ß2-5) coexist in human lens, as well as in cultured SV-40 transformed human lens epithelial cells (HLE-B3) (Exp Eye Res. 81:165-175; 2005). 17-beta estradiol (E2) modulates the degree of oxidative stress-induced depolarization of mitochondrial membrane potential (MMP) in HLE-B3 cells, following H2O2 insult, by activation of mitogen-activated protein kinase (MAPK) (Mitochondrion 5:235-247; 2005). This study resolved whether gender played a role in the protection mechanism based upon differences in ER-ß isoform expression, receptor localization in mitochondria and response to estrogen-mediated mitochondrial protection against oxidative stress employing cultured populations of normal male and female human lens epithelial (nHLE) cells.
: nHLE cell cultures were prepared from explants of post-mortum male and female donors across a wide age distribution. A triple primer PCR assay (Exp Eye Res. 81:165-175; 2005) was used to determine the proportional distribution of the receptor isoforms (wtER-ß1, ß2 and ß5) from the total ER-ß message pool in male and female cell cultures. Subcellular localization of ERß isoforms was determined using conventional immunofluorescence techniques and affinity purified polyclonal antibodies specific for wtER-ß1, ß2 and ß5. To examine changes in MMP, the potentiometric fluorescent compound, JC-1, was used after cell cultures were exposed to peroxide ± pretreatment with E2.
Male and female nHLE cells express wtER-ß1, ER-ß2 and ER-ß5 splice variants in similar ratios. Confocal microscopy and immunofluorescence revealed localization of the wild-type receptor in both the peripheral mitochondrial arrays and perinuclear mitochondria (along with weaker internal nuclear staining) of both male and female nHLE cells. The ER-ß2 and ER-ß5 isoforms were distributed in the cytosol; no association with the mitochondria was detected. Both male and female nHLE cells treated with E2 (1µM) showed similar levels of protection against oxidative stress.
While we have yet to establish whether wtER-ß1 (in mitochondria) plays a definitive role in the E2-mediated mitochondrial protection mechanism, these observations establish that prevention of depolarization of the MMP must be regarded as gender-independent.
This PDF is available to Subscribers Only