Effects of Estrogen on Rhesus Monkey Retinal Capillary Endothelial Cell Proliferation

Abstract

Purpose:: Endothelial cell multiplication is a fundamental mechanism of proliferative diabetic retinopathy (PDR), however, PDR is rarely observed in pre-pubertal human females. Estrogen is known to increase cell proliferation and may be a factor in PDR. Pre-pubescent girls may be protected because they do not experience the titers of estrogen typical of older individuals. This protection against PDR might be extended to other age groups if an appropriate modification of estrogen response by retinal capillary endothelial cells (RCECs) could be achieved. A rhesus monkey (Macaca mulatta) naturally transformed retina and choroidal capillary endothelial cell line is available. The purpose of this study is to test the efficacy of 17 ß Estradiol in modulating cell proliferation, using cultures of Rhesus monkey retinal capillary endothelial cells (ATCC #CRL-1780).

Methods:: Cell cultures were exposed to 10 nmolar concentrations of 17 ß estradiol. Controls contained no estrogen. Cell growth rates were assessed by cell counts and Bradford protein assays.

Results:: A 10 nM concentration of 17 ß Estradiol demonstrates an increased proliferation of (RCECs) (p<0.001) as determined by an increase in cell counts (from 6.96X10⁴ to 7.24X10⁴ cells/ml) and increased total protein concentration (from 4 to 6.7 µg) per sample.

Conclusions:: 17 ß Estradiol increases proliferation of rhesus monkey retinal capillary endothelial cells. This cell line provides a model to test the effects of selective estrogen receptor modulators and/or estrogen blockers on cell proliferation.

Keywords: diabetic retinopathy • retinal neovascularization • diabetes