Androgen-Androgen Receptor System Protects against Angiotensin II-Induced Vascular Remodeling

• Published in: Endocrinology (Philadelphia) 2009-06, Vol.150 (6), p.2857-2864
• Main Authors: Ikeda, Yasumasa, Aihara, Ken-ichi, Yoshida, Sumiko, Sato, Takashi, Yagi, Shusuke, Iwase, Takashi, Sumitomo, Yuka, Ise, Takayuki, Ishikawa, Kazue, Azuma, Hiroyuki, Akaike, Masashi, Kato, Shigeaki, Matsumoto, Toshio
• Format: Article
• Language: English
• Subjects: Adenine; Age; AKT protein; Androgen receptors; Androgens; Androgens - metabolism; Angiotensin; Angiotensin II; Angiotensin II - adverse effects; Angiotensin II - pharmacology; Animals; Aorta; Aorta, Thoracic - drug effects; Aorta, Thoracic - metabolism; Atherosclerosis - chemically induced; Atherosclerosis - metabolism; Atherosclerosis - prevention & control; Bioavailability; Biological and medical sciences; c-Jun protein; Cardiovascular diseases; Collagen; Collagen (type I); Collagen (type III); Coronary artery; Coronary vessels; Coronary Vessels - drug effects; Coronary Vessels - metabolism; Disease Models, Animal; Fibrosis; Fundamental and applied biological sciences. Psychology; Gene expression; Heart diseases; JNK protein; Kinases; Lipid Peroxidation; Lipids; Male; Males; MAP Kinase Kinase 4 - metabolism; Metabolites; Mice; Mice, Inbred C57BL; Mice, Knockout; NAD(P)H oxidase; Nicotinamide; Nicotinamide adenine dinucleotide; Nitric oxide; Nitric Oxide - metabolism; Nitric-oxide synthase; Oxidative stress; Peroxidation; Phosphorylation; Proto-Oncogene Proteins c-akt - metabolism; Receptor, Angiotensin, Type 1 - metabolism; Receptor, Angiotensin, Type 2 - metabolism; Receptors; Receptors, Androgen - genetics; Receptors, Androgen - metabolism; Stimulation; Superoxides - metabolism; Thiobarbituric Acid Reactive Substances - metabolism; Thorax; Transcription factors; Transforming Growth Factor beta1 - metabolism; Transforming growth factor-b; Vasoconstrictor Agents - adverse effects; Vasoconstrictor Agents - pharmacology; Vertebrates: endocrinology
• ISSN: 0013-7227; 1945-7170
• DOI: 10.1210/en.2008-1254

Age-related andropause promotes cardiovascular disease in males. Although we had previously reported that the androgen-androgen receptor (AR) system plays important roles in cardiac growth and remodeling, the system’s involvement in vascular remodeling remains unclear. To clarify this role, 25-wk-old male AR knockout (ARKO) mice and littermate male wild-type (WT) mice were divided into two groups with and without angiotensin II (Ang II) administration (2.0 mg/kg · d) for 14 d, respectively. No morphological differences in the coronary artery and thoracic aorta were observed between the groups without Ang II. Ang II stimulation markedly increased medial thickness and perivascular fibrosis in ARKO mice, with enhanced TGF-β1, collagen type I, and collagen type III gene expression in the aorta. Ang II stimulation also prominently increased superoxide production, lipid peroxidation, and gene expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase components in ARKO mice compared with WT mice. In addition, phosphorylation of c-Jun N-terminal kinase (JNK) and phosphorylated (Smad2/3) was remarkably enhanced in Ang II-treated ARKO mice compared with Ang II-treated WT mice. Notably, daily urinary nitric oxide (NO) metabolites excretion as a marker of NO bioavailability, aortic endothelial NO synthase expression and phosphorylation, and Akt phosphorylation were significantly reduced in ARKO mice compared with WT mice, regardless of Ang II stimulation. In conclusion, the androgen-AR system is required for the preservation of NO bioavailability through Akt-endothelial NO synthase system activation and exerts protective effects against Ang II-induced vascular remodeling by regulating oxidative stress, c-Jun N-terminal kinase (JNK) signaling, and the TGF-β-phosphorylated Smad pathway. Excessive angiotensin II causes accelerated vascular remodeling in male androgen receptor gene knockout mice via dysregulation of eNOS system, JNK signaling, and TGF-β-Smad pathway.