title: The NRF2 knockout rat: a new animal model to study endothelial dysfunction, oxidant stress, and microvascular rarefaction.
abstract: Nuclear factor (erythroid-derived 2)-like-2 (NRF2) is a master antioxidant and cell protective transcription factor that upregulates antioxidant defenses. In this study we developed a strain of Nrf2 null mutant rats to evaluate the role of reduced NRF2-regulated antioxidant defenses in contributing to endothelial dysfunction and impaired angiogenic responses during salt-induced ANG II suppression. Nrf2(-/-) mutant rats were developed using transcription activator-like effector nuclease technology in the Sprague-Dawley genetic background, and exhibited a 41-bp deletion that included the start codon for Nrf2 and an absence of immunohistochemically detectable NRF2 protein. Expression of mRNA for the NRF2-regulated indicator enzymes heme oxygenase-1, catalase, superoxide dismutase 1, superoxide dismutase 2, and glutathione reductase was significantly lower in livers of Nrf2(-/-) mutant rats fed high salt (HS; 4% NaCl) for 2 wk compared with wild-type controls. Endothelium-dependent dilation to acetylcholine was similar in isolated middle cerebral arteries (MCA) of Nrf2(-/-) mutant rats and wild-type littermates fed low-salt (0.4% NaCl) diet, and was eliminated by short-term (3 days) HS diet in both strains. Low-dose ANG II infusion (100 ng/kg sc) reversed salt-induced endothelial dysfunction in MCA and prevented microvessel rarefaction in wild-type rats fed HS diet, but not in Nrf2(-/-) mutant rats. The results of this study indicate that suppression of NRF2 antioxidant defenses plays an essential role in the development of salt-induced oxidant stress, endothelial dysfunction, and microvessel rarefaction in normotensive rats and emphasize the potential therapeutic benefits of directly upregulating NRF2-mediated antioxidant defenses to ameliorate vascular oxidant stress in humans.
authors.affiliation: Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and.
authors.forename: Jessica R C
authors.initials: JR
authors.lastname: Priestley
authors.affiliation: Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and.
authors.forename: Katie E
authors.initials: KE
authors.lastname: Kautenburg
authors.affiliation: Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and.
authors.forename: Marc C
authors.initials: MC
authors.lastname: Casati
authors.affiliation: Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and.
authors.forename: Bradley T
authors.initials: BT
authors.lastname: Endres
authors.affiliation: Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, Wisconsin.
authors.forename: Aron M
authors.initials: AM
authors.lastname: Geurts
authors.affiliation: Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and jlombard@mcw.edu.
authors.forename: Julian H
authors.initials: JH
authors.lastname: Lombard
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D002196:Capillaries / Q000473:pathology; D004730:Endothelium, Vascular / Q000503:physiopathology*; D055786:Gene Knockout Techniques; D007150:Immunohistochemistry; D008833:Microcirculation; D020768:Middle Cerebral Artery / Q000187:drug effects; D051267:NF-E2-Related Factor 2 / Q000235:genetics*; D018384:Oxidative Stress; D051381:Rats; D017207:Rats, Sprague-Dawley; D014178:Translocation, Genetic / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D051267:NF-E2-Related Factor 2; C495637:Nfe2l2 protein, rat; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D000804:Angiotensin II; D000109:Acetylcholine
keywords: angiogenesis; angiotensin II; endothelium; nitric oxide; nuclear factor (erythroid-derived 2)-like-2; salt