Knockout of TRPV1 Exacerbates Ischemia-reperfusion-induced Renal Inflammation and Injury in Obese Mice.

Abstract

Transient receptor potential vanilloid type 1 (TRPV1) has anti-inflammatory properties. The present study aimed to investigate the role of TRPV1 in renal inflammatory responses and tissue injury following renal ischemia-reperfusion (I/R) in diet-induced obese mice. TRPV1 knockout and wild type mice were fed a normal or western diet (WD) for 23 weeks and were then subjected to renal I/R injury. TRPV1 knockout mice showed enhanced WD-induced renal macrophage infiltration and collagen deposition. Knocking out TRPV1 exacerbated renal I/R-induced increase of malondialdehyde, interleukin-6, monocyte chemoattractant protein-1, and NF-ĸB in obese mice. Similar results were observed in the expression of phosphorylated Smad1 and Smad2/3. Blockade of calcitonin gene-related peptide (CGRP) receptors with CGRP8-37 worsened the I/R-induced renal inflammation and injury. Our data indicate that preserving TRPV1 expression and function may prevent renal I/R injury in obesity likely through alleviating inflammatory responses.