Antioxidant intervention prevents renal neovascularization in hypercholesterolemic pigs

Alejandro R. Chade, Michael D. Bentley, Xiangyang Zhu, Martin Rodriguez-Porcel, Sara Niemeyer, Beatriz Amores-Arriaga, Claudio Napoli, Erik L. Ritman, Amir Lerman, Lilach O. Lerman

Research output: Contribution to journalArticlepeer-review

62 Scopus citations

Abstract

Experimental hypercholesterolemia (HC) may lead to microvascular neovascularization, but the underlying pathogenic mechanism remains unclear. We tested the hypothesis that HC-induced intra-renal neovascularization is associated with inflammation and increased oxidative stress, and would be prevented by chronic antioxidant intervention. Kidneys were excised from pigs after a 12-wk normal (n = 10) or HC diet (n = 8), or HC diet supplemented daily with antioxidant vitamins C (1 g) and E (100 IU/kg) (HC + vitamins, n = 7). Renal cortical samples were then scanned three dimensionally with micro-computed tomography, and microvessels were counted in situ. Blood and tissue samples were removed for measurements of superoxide dismutase (SOD) activity, protein expression of the NADP(H)-oxidase subunits gp91phox, p47phox, and p67phox, vascular endothelial growth factor (VEGF) levels and mRNA, VEGF receptors (Flt-1 and Flk-1), the proinflammatory transcription factor NFκB, and the oxidized LDL receptor LOX-1. Microvascular spatial density was significantly elevated in HC compared with normal kidneys but preserved in HC + vitamins. Expression of gp91phox and p67phox was decreased in HC pigs after antioxidant intervention, and SOD improved. The increased renal expression of VEGF and Flk-1 in HC was blunted in HC + vitamins, as were the significant increases in LOX-1, NFκB, and interstitial fibrosis. This study shows that renal cortical neovascularization elicited by diet-induced HC is associated with renal inflammation, fibrosis, and upregulation of VEGF and its receptor Flk-1, likely mediated by increased endogenous oxidative stress. Chronic antioxidant supplementation may preserve the kidney in HC.

Original languageEnglish (US)
Pages (from-to)1816-1825
Number of pages10
JournalJournal of the American Society of Nephrology
Volume15
Issue number7
DOIs
StatePublished - Jul 2004

ASJC Scopus subject areas

  • Nephrology

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