title: 3-Methylcholanthrene/Aryl-Hydrocarbon Receptor-Mediated Hypertension Through eNOS Inactivation.
abstract: Endothelial nitric oxide synthase (eNOS) modulates vascular blood pressure and is predominantly expressed in endothelial cells and activated through the protein kinase B (Akt/PKB)-dependent pathway. We previously reported that 3-methylcholanthrene (3MC) activates the aryl hydrocarbon receptor (AhR) and reduces PI3K/Akt phosphorylation. This study investigated the mechanism underlying the downregulatory effects of 3-MC on nitric oxide (NO) production occurring through the AhR/RhoA/Akt-mediated mechanism. The mechanism underlying the effects of 3-MC on eNOS activity and blood pressure was examined in vitro and in vivo through genetic and pharmacological approaches. Results indicated that 3-MC modified heat shock protein 90 (HSP90), caveolin-1, dynein, and eNOS mRNA and protein expression through the AhR/RhoA-dependent mechanism in mouse cerebral vascular endothelial cells (MCVECs) and that 3-MC reduced eNOS phosphorylation through the AhR/RhoA-mediated inactivation of Akt1. The upregulation of dynein expression was associated with decreased eNOS dimer formation (eNOS dimer; an activated form of the enzyme). Coimmunoprecipitation assay results indicated that 3-MC significantly reduced the interaction between eNOS and its regulatory proteins, including Akt1 and HSP90, but increased the interaction between eNOS and caveolin-1. Immunofluorescence and Western blot analysis revealed that 3-MC reduced the amount of membrane-bound activated eNOS, and a modified Griess assay revealed that 3-MC concomitantly reduced NO production. However, simvastatin reduced 3-MC-mediated murine hypertension. Our study results indicate that AhR, RhoA, and eNOS have major roles in blood pressure regulation. Statin intervention might provide a potential therapeutic approach for reducing hypertension caused by 3-MC. J. Cell. Physiol. 232: 1020-1029, 2017. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Departmentof Physiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Chih-Cheng
authors.initials: CC
authors.lastname: Chang
authors.affiliation: Department of Nephrology, Taipei Medical University Shuang-Ho Hospital, Taipei, Taiwan.
authors.forename: Yung-Ho
authors.initials: YH
authors.lastname: Hsu
authors.affiliation: Department of Anatomy and Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Hsiu-Chu
authors.initials: HC
authors.lastname: Chou
authors.affiliation: Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.
authors.forename: Yuan-Chii G
authors.initials: YG
authors.lastname: Lee
authors.affiliation: Departmentof Physiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Shu-Hui
authors.initials: SH
authors.lastname: Juan
mesh_terms: D000818:Animals; D054022:Cerebrum / Q000098:blood supply; D015536:Down-Regulation / Q000187:drug effects; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D006973:Hypertension / Q000201:enzymology* / Q000473:pathology; D008748:Methylcholanthrene / Q000494:pharmacology*; D051379:Mice; D008954:Models, Biological; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D009599:Nitroprusside / Q000494:pharmacology / Q000627:therapeutic use; D011485:Protein Binding / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D018336:Receptors, Aryl Hydrocarbon / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D019821:Simvastatin / Q000494:pharmacology / Q000627:therapeutic use; D013997:Time Factors; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
chemical_list: D018336:Receptors, Aryl Hydrocarbon; D009599:Nitroprusside; D009569:Nitric Oxide; D008748:Methylcholanthrene; D019821:Simvastatin; D052250:Nitric Oxide Synthase Type III; D051057:Proto-Oncogene Proteins c-akt; D020742:rhoA GTP-Binding Protein