title: PVN adenovirus-siRNA injections silencing either NOX2 or NOX4 attenuate aldosterone/NaCl-induced hypertension in mice.
abstract: Mineralocorticoid excess increases superoxide production by activating NADPH oxidase (NOX), and intracerebroventricular infusions of NADPH oxidase inhibitors attenuate aldosterone (Aldo)/salt-induced hypertension. It has been hypothesized that increased reactive oxygen species (ROS) in the brain may be a key mechanism in the development of hypertension. The present study investigated the brain regional specificity of NADPH oxidase and the role of NOX2 and NOX4 NADPH oxidase subunits in the hypothalamic paraventricular nucleus (PVN) in Aldo/salt-induced hypertension. PVN injections of adenoviral vectors expressing small interfering (si)RNA targeting NOX2 (AdsiRNA-NOX2) or NOX4 (AdsiRNA-NOX4) mRNAs were used to knock down NOX2 and NOX4 proteins. Three days later, delivery of Aldo (0.2 mg·kg(-1)·day(-1) sc) via osmotic pump commenced and 1% NaCl was provided in place of water. PVN injections of either AdsiRNA-NOX2 or AdsiRNA-NOX4 significantly attenuated the development of Aldo/NaCl-induced hypertension. In an additional study, Aldo/salt-induced hypertension was also significantly attenuated in NOX2 (genomic) knockout mice compared with wild-type controls. When animals from both functional studies underwent ganglionic blockade, there was a reduced fall in blood pressure in the NOX2 and NOX4 knockdown/knockout mice. Western blot analyses of the PVN of siRNA-NOX2- or siRNA-NOX4-injected mice confirmed a marked reduction in the expression of NOX2 or NOX4 protein. In cultured PVN neurons, silencing either NOX2 or NOX4 protein production by culturing PVN cells with siRNA-NOX2 or siRNA-NOX4 attenuated Aldo-induced ROS. These data indicate that both NOX2 and NOX4 in the PVN contribute to elevated sympathetic activity and the hypertensivogenic actions induced by mineralocorticoid excess.
authors.affiliation: Departments of Psychology, University of Iowa, Iowa City, IA 52242, USA. Baojian-Xue@uiowa.edu
authors.forename: Baojian
authors.initials: B
authors.lastname: Xue
authors.forename: Terry G
authors.initials: TG
authors.lastname: Beltz
authors.forename: Ralph F
authors.initials: RF
authors.lastname: Johnson
authors.forename: Fang
authors.initials: F
authors.lastname: Guo
authors.forename: Meredith
authors.initials: M
authors.lastname: Hay
authors.forename: Alan Kim
authors.initials: AK
authors.lastname: Johnson
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000450:Aldosterone / Q000494:pharmacology; D000818:Animals; D001341:Autonomic Nervous System / Q000201:enzymology / Q000503:physiopathology; D001794:Blood Pressure / Q000502:physiology; D005260:Female; D015316:Genetic Therapy / Q000295:instrumentation / Q000379:methods*; D006973:Hypertension / Q000139:chemically induced / Q000503:physiopathology / Q000628:therapy*; D007260:Infusion Pumps; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D000074662:NADPH Oxidase 2; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000235:genetics* / Q000378:metabolism; D010286:Paraventricular Hypothalamic Nucleus / Q000201:enzymology* / Q000503:physiopathology*; D034741:RNA, Small Interfering / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology
chemical_list: D008562:Membrane Glycoproteins; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D012965:Sodium Chloride; D000450:Aldosterone; C488842:Cybb protein, mouse; D000074662:NADPH Oxidase 2; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C422943:Nox4 protein, mouse