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Blockade of endogenous angiotensin II type I receptor agonistic autoantibody activity improves mitochondria reactive oxygen species and hypertension in a rat model of preeclampsia

Authors

  • V.R. Vaka
  • M. Cunningham
  • E. Deer
  • M. Franks
  • T. Ibrahim
  • L. Amaral
  • N. Usry
  • D.C. Cornelius
  • R. Dechend
  • G. Wallukat
  • B. LaMarca

Journal

  • American Journal of Physiology Regulatory Integrative and Comparative Physiology

Citation

  • Am J Physiol Regul Integr Comp Physiol

Abstract

  • Preeclampsia (PE) is characterized by new onset hypertension that usually occurs in the 3rd trimester of pregnancy, and is associated with oxidative stress and angiotensin II type 1 receptor agonistic autoantibodies (AT1-AAs). Inhibition of the AT1-AAs in the reduced uterine perfusion pressure (RUPP) rat, a model of PE, attenuates hypertension and many other characteristics of PE. We have previously shown that mitochondrial (mt) oxidative stress (ROS) is a newly described PE characteristic exhibited by the RUPP rat that contributes to hypertension. However, the factors that cause mtROS in PE or RUPP are unknown. Thus, the objective of the current study is to use pharmacologic inhibition of AT1-AAs to examine their role in mtROS in the RUPP rat model of PE. AT1-AA inhibition in the RUPP rats was achieved by administration of an epitope binding peptide (´n7AAc´). Female Sprague Dawley rats were divided into two groups; RUPP and RUPP+AT1-AA inhibition (RUPP+´n7AAc´). On day 14 of gestation (GDay), RUPP surgery was performed, ´n7AAc´ peptide (2µg/μL) was administered by mini-osmotic pumps in a subset of RUPP rats; GDay 19, sera, placentas, and kidneys were collected. Mt respiration and mtROS were measured in isolated mitochondria using the Oxygraph 2K and fluorescent microplate reader, respectively. Placental and renal mt respiration and mtROS were improved in RUPP+´n7AAc´ rats compared to RUPP controls. Moreover, endothelial cells (HUVECs) treated with RUPP+´n7AAc´ sera exhibited less mtROS compared to those treated with RUPP sera. Overall, our findings suggest that AT1-AA signaling is one stimulus of mtROS during PE.


DOI

doi:10.1152/ajpregu.00179.2019