Cooke Christy-Lynn M, Brockelsby Jeremy C, Baker Philip N, Davidge Sandra T
Perinatal Research Centre, Department of Obstetrics, University of Alberta, Edmonton, Alberta, Canada.
Hypertens Pregnancy. 2003;22(2):173-84. doi: 10.1081/PRG-120021068.
A leading theory of the pathophysiology of preeclampsia is that oxidative stress induces vascular endothelial cell dysfunction. Advanced glycation end products (AGEs) form when aldose sugars react nonenzymatically with proteins under conditions of oxidative stress. AGEs are circulating molecules and can generate reactive oxygen species and vascular dysfunction (in diabetes and atherosclerosis) through an association with cell surface receptors (RAGE). RAGE is a multiligand receptor, expressed in vascular tissue, which is upregulated by its own ligands. Insulin resistance and obesity are risk factors for developing preeclampsia, as well as being conditions that would increase RAGE levels. Thus, we hypothesized that women with preeclampsia will have elevated levels of RAGE protein compared with normal pregnant women. Biopsies of nonlaboring myometrium as well as omentum were taken from normal pregnant and preeclamptic women. Nonpregnant samples were obtained at the time of hysterectomy. Tissue sections were immunostained with anti-RAGE as well as anti-alpha-actin and anti-von Willebrand factor (to identify blood vessels and intact endothelial cells). Staining intensity was qualitatively described as well as given an intensity score, with the identity of the section concealed. Nonpregnant myometrial and omental vessels showed very low to undetectable levels of RAGE staining. Pregnancy induced a significant increase in RAGE protein levels in both myometrium and omental vasculature. Blood vessels from women with preeclampsia consistently had intense staining for RAGE in both vessel beds. Thus, our data suggest that since RAGE activation can induce similar pathophysiologic changes to those observed in women with preeclampsia (including NFkappaB activation, increased TNFalpha and endothelin), elevated RAGE protein may be contributing to the vascular dysfunction in preeclampsia.
