Differential expression of HSP90α and heme oxygenase in cord blood RBC during preeclampsia

Abstract

Preeclampsia is a multisystem disorder with profound implications on both mother and fetus. Analysis of umbilical cord blood red blood cell (RBC) changes shall depict the fetal response to pregnancy-specific complications like preeclampsia. This study aims to analyze the regulation relationship between HSP90α and heme oxygenase-2 (HO-2) in cord blood RBC during preeclampsia. The lipid hydroperoxide (LHP) and 3-nitrotyrosine (3-NT) levels were measured as stress markers in cord blood RBC of both subjects. The impact of stress on RBC was assessed by measuring the level of membrane bound enzymes and assessing the changes in cord blood RBC. The expression of HSP90α and HO-2 were analyzed by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry analysis, respectively. There was significant increase in the level of LHP (p < 0.01), 3-NT (p < 0.05), HSP90α (p < 0.01) with decrease in the expression of HO-2 (p < 0.05) in cord blood RBC of preeclamptic subjects compared to normotensive subjects. Similarly, the membrane damage in preeclamptic RBC was assessed by spectrophotometrically and found to be increased by 41.7%, along with increase in number of nucleated RBC. The antiproliferative effect of carbon monoxide under stress might decrease the expression of HO-2 under conditions when there is an increasing need for RBC. The role of HSP90α level in cord blood RBC is discussed with reference to nitrative stress in preeclampsia. This study concludes the increased expression of nucleated RBC, HSP90α and corresponding decreased expression of HO-2 in such hypoxic condition may play a protective role; to prevent cord blood RBC against stress induced damage during preeclampsia.