title: Membrane trafficking of NADPH oxidase p47(phox) in paraventricular hypothalamic neurons parallels local free radical production in angiotensin II slow-pressor hypertension.
abstract: NADPH oxidase-generated reactive oxygen species (ROS) are highly implicated in the development of angiotensin II (AngII)-dependent hypertension mediated in part through the hypothalamic paraventricular nucleus (PVN). This region contains vasopressin and non-vasopressin neurons that are responsive to cardiovascular dysregulation, but it is not known whether ROS is generated by one or both cell types in response to "slow-pressor" infusion of AngII. We addressed this question using ROS imaging and electron microscopic dual labeling for vasopressin and p47(phox), a cytoplasmic NADPH oxidase subunit requiring mobilization to membranes for the initiation of ROS production. C57BL/6 mice or vasopressin-enhanced green fluorescent protein (VP-eGFP) mice were infused systemically with saline or AngII (600 ng · kg(-1) · min(-1), s.c.) for 2 weeks, during which they slowly developed hypertension. Ultrastructural analysis of the PVN demonstrated p47(phox) immunolabeling in many glial and neuronal profiles, most of which were postsynaptic dendrites. Compared with saline, AngII recipient mice had a significant increase in p47(phox) immunolabeling on endomembranes just beneath the plasmalemmal surface (+42.1 ± 11.3%; p < 0.05) in non-vasopressin dendrites. In contrast, AngII infusion decreased p47(phox) immunolabeling on the plasma membrane (-35.5 ± 16.5%; p < 0.05) in vasopressin dendrites. Isolated non-VP-eGFP neurons from the PVN of AngII-infused mice also showed an increase in baseline ROS production not seen in VP-eGFP neurons. Our results suggest that chronic low-dose AngII may offset the homeostatic control of blood pressure by differentially affecting membrane assembly of NADPH oxidase and ROS production in vasopressin and non-vasopressin neurons located within the PVN.
authors: Brain and Mind Research Institute, Weill Cornell Medical College of Cornell University, New York, New York 10065, USA.
authors: Christal G
authors: CG
authors: Coleman
authors: Gang
authors: G
authors: Wang
authors: Giuseppe
authors: G
authors: Faraco
authors: Jose
authors: J
authors: Marques Lopes
authors: Elizabeth M
authors: EM
authors: Waters
authors: Teresa A
authors: TA
authors: Milner
authors: Costantino
authors: C
authors: Iadecola
authors: Virginia M
authors: VM
authors: Pickel
mesh_terms: D000804:Angiotensin II / Q000008:administration & dosage / Q000009:adverse effects; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D003712:Dendrites / Q000378:metabolism / Q000648:ultrastructure; D004334:Drug Administration Schedule; D016503:Drug Delivery Systems; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D049452:Green Fluorescent Proteins / Q000235:genetics; D057809:HEK293 Cells; D006801:Humans; D006973:Hypertension / Q000139:chemically induced / Q000473:pathology*; D066298:In Vitro Techniques; D007425:Intracellular Membranes / Q000378:metabolism / Q000648:ultrastructure; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D016253:Microscopy, Immunoelectron; D016202:N-Methylaspartate / Q000494:pharmacology; D019255:NADPH Oxidases / Q000378:metabolism*; D009457:Neuroglia / Q000378:metabolism / Q000648:ultrastructure; D009474:Neurons / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D010286:Paraventricular Hypothalamic Nucleus / Q000473:pathology*; D021381:Protein Transport / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism*; D014162:Transfection; D014662:Vasoconstrictor Agents / Q000008:administration & dosage / Q000009:adverse effects; D014667:Vasopressins / Q000235:genetics / Q000378:metabolism
chemical_list: D018690:Excitatory Amino Acid Agonists; D017382:Reactive Oxygen Species; D014662:Vasoconstrictor Agents; C485184:enhanced green fluorescent protein; D014667:Vasopressins; D000804:Angiotensin II; D049452:Green Fluorescent Proteins; D016202:N-Methylaspartate; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1