(Pro)renin Receptor Blockade Prevents Increases in Systolic Blood Pressure, Sodium Retention, and αENaC Protein Expression in the Kidney of 2K1C Goldblatt Mice

TL;DR

Blocking the (pro)renin receptor in mice prevents high blood pressure and sodium retention in a model of kidney-related hypertension.

Contribution

This study shows that PRR blockade prevents early hypertensive changes in renovascular hypertension.

Findings

Renal artery obstruction increased blood pressure and αENaC expression in mice.

PRO20 peptide reduced blood pressure and intrarenal Ang II levels in 2K1C mice.

PRR blockade attenuated sodium retention and αENaC upregulation in non-clipped kidneys.

Abstract

Physiological control of blood pressure (BP) and extracellular fluid volume is mediated by the action of the renin-angiotensin system (RAS). The presence of RAS components throughout the nephron has been widely discussed. The (pro)renin receptor (PRR) is a member of the RAS widely expressed in the body of humans and rodents. In the kidney, PRR is expressed in mesangial cells, renal vasculature, and tubules of the proximal and distal nephron. Binding of the PRR to renin and prorenin promotes angiotensin (Ang) I-mediated sodium (Na+) reabsorption via the epithelial sodium channel (ENaC). The Goldblatt 2-kidney 1-clip (2K1C) is a model of experimental renovascular hypertension that displays activation of systemic and intrarenal RAS. We use the 2K1C hypertension mouse model for 7 days to evaluate the role of the PRR on renal αENaC expression, Na+ reabsorption, and BP using pharmacological systemic blockade of the PRR with PRO20 peptide. Mice undergoing or not to 2K1C surgery (0.13 mm clip internal gap) were chronically infused with PRO20 and compared to sham (control) mice to assess changes in systolic BP (SBP) and diastolic BP (DBP), intrarenal angiotensin-converting enzyme (ACE) activity, Ang II, and renal αENaC expression and natriuretic responses after a saline challenge. Renal artery obstruction increased SBP and DBP, intrarenal ACE activity, Ang II levels, Na+ retention, and αENaC expression in both kidneys. PRO20 prevented the increases in SBP, DBP, attenuated Na+ retention, and blunted intrarenal Ang II and αENaC levels in non-clipped kidneys of 2K1C mice. Chronic infusion of the PRR blocker PRO20 for 7 days prevents hypertensive responses in part due to impaired αENaC upregulation and intrarenal Ang II formation in the early phase of the development of renovascular hypertension in 2K1C Goldblatt mice.

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