title: Nicotinamide Adenine Dinucleotide Phosphate Oxidase-Mediated Redox Signaling and Vascular Remodeling by 16α-Hydroxyestrone in Human Pulmonary Artery Cells: Implications in Pulmonary Arterial Hypertension.
abstract: Estrogen and oxidative stress have been implicated in pulmonary arterial hypertension (PAH). Mechanisms linking these systems are elusive. We hypothesized that estrogen metabolite, 16α-hydroxyestrone (16αOHE1), stimulates nicotinamide adenine dinucleotide phosphate oxidase (Nox)-induced reactive oxygen species (ROS) generation and proliferative responses in human pulmonary artery smooth muscle cells (hPASMCs) and that in PAH aberrant growth signaling promotes vascular remodeling. The pathophysiological significance of estrogen-Nox-dependent processes was studied in female Nox1(-/-) and Nox4(-/-) mice with PAH. PASMCs from control subjects (control hPASMCs) and PAH patients (PAH-hPASMCs) were exposed to estrogen and 16αOHE1 in the presence/absence of inhibitors of Nox, cytochrome P450 1B1, and estrogen receptors. Estrogen, through estrogen receptor-α, increased Nox-derived ROS and redox-sensitive growth in hPASMCs, with greater effects in PAH-hPASMCs versus control hPASMCs. Estrogen effects were inhibited by cytochrome P450 1B1 blockade. 16αOHE1 stimulated transient ROS production in hPASMCs, with sustained responses in PAH-hPASMCs. Basal expression of Nox1/Nox4 was potentiated in PAH-hPASMCs. In hPASMCs, 16αOHE1 increased Nox1 expression, stimulated irreversible oxidation of protein tyrosine phosphatases, decreased nuclear factor erythroid-related factor 2 activity and expression of nuclear factor erythroid-related factor 2-regulated antioxidant genes, and promoted proliferation. This was further amplified in PAH-hPASMCs. Nox1(-/-) but not Nox4(-/-) mice were protected against PAH and vascular remodeling. Our findings demonstrate that in PAH-hPASMCs, 16αOHE1 stimulates redox-sensitive cell growth primarily through Nox1. Supporting this, in vivo studies exhibited protection against pulmonary hypertension and remodeling in Nox1(-/-) mice. This study provides new insights through Nox1/ROS and nuclear factor erythroid-related factor 2 whereby 16αOHE1 influences hPASMC function, which when upregulated may contribute to vascular injury in PAH, particularly important in women.
authors.affiliation: From the Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom.
authors.forename: Katie Y
authors.initials: KY
authors.lastname: Hood
authors.affiliation: From the Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom.
authors.forename: Augusto C
authors.initials: AC
authors.lastname: Montezano
authors.affiliation: From the Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom.
authors.forename: Adam P
authors.initials: AP
authors.lastname: Harvey
authors.affiliation: From the Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom.
authors.forename: Margaret
authors.initials: M
authors.lastname: Nilsen
authors.affiliation: From the Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom.
authors.forename: Margaret R
authors.initials: MR
authors.lastname: MacLean
authors.affiliation: From the Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom. rhian.touyz@glasgow.ac.uk.
authors.forename: Rhian M
authors.initials: RM
authors.lastname: Touyz
mesh_terms: D000818:Animals; D002478:Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D005260:Female; D006801:Humans; D006894:Hydroxyestrones / Q000494:pharmacology*; D006976:Hypertension, Pulmonary / Q000503:physiopathology*; D051379:Mice; D009249:NADP / Q000378:metabolism*; D000074624:NADPH Oxidase 1; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction / Q000187:drug effects*; D011651:Pulmonary Artery / Q000166:cytology / Q000378:metabolism; D015398:Signal Transduction; D066253:Vascular Remodeling / Q000187:drug effects / Q000235:genetics / Q000502:physiology
chemical_list: D006894:Hydroxyestrones; D009249:NADP; D000074624:NADPH Oxidase 1; D019255:NADPH Oxidases; C402799:NOX1 protein, human
keywords: NADPH oxidase; estrogens; hypertension, pulmonary; models, animal; superoxide