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Higaki A, Mogi M, Iwanami J, Min LJ, Bai HY, Shan BS, Kukida M, Yamauchi T, Tsukuda K, Kan-No H, Ikeda S, Higaki J, Horiuchi M. Beneficial Effect of Mas Receptor Deficiency on Vascular Cognitive Impairment in the Presence of Angiotensin II Type 2 Receptor. J Am Heart Assoc 2018; 7:JAHA.117.008121. [PMID: 29431106 PMCID: PMC5850265 DOI: 10.1161/jaha.117.008121] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
BACKGROUND The classical renin-angiotensin system is known as the angiotensin (Ang)-converting enzyme/Ang II/Ang type 1 receptor axis, which induces various organ damage including cognitive decline. The angiotensin-converting enzyme 2/Ang-(1-7)/Mas axis is known to exert antagonistic actions against the classical renin-angiotensin system axis in the cardiovascular system. However, its roles in the brain remain unclear. We examined possible roles of the angiotensin-converting enzyme 2/Ang-(1-7)/Mas axis in cognitive function, employing vascular cognitive impairment model mice. METHODS AND RESULTS Male 10-week-old C57BL6 (wild-type mice, Mas1 knockout mice, Ang II type 2 receptor knockout mice, and Ang II type 2 receptor/Mas1 double knockout mice were subjected to bilateral carotid artery stenosis (BCAS) surgery. Six weeks after treatment, they were subjected to cognitive tasks. Brain samples were used for histopathological analysis. Cognitive function was significantly impaired in wild-type and double knockout mice after BCAS. On the other hand, the cognitive function of Mas1 knockout mice was maintained in spite of the reduction of cerebral blood flow with BCAS. Total cell number in the dentate gyrus region was significantly reduced after BCAS in wild-type but not in Mas1 knockout mice. The number of doublecortin-positive cells in the subgranular zone was not significantly different between wild-type and Mas1 knockout mice. Ang-(1-7) administration did not improve cognitive function in all mice after BCAS surgery. CONCLUSIONS Lack of the Mas receptor may have a protective effect against chronic brain ischemia when the Ang II type 2 receptor exists.
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Affiliation(s)
- Akinori Higaki
- Department of Molecular Cardiovascular Biology and Pharmacology, Graduate School of Medicine, Ehime University, Tohon, Ehime, Japan.,Department of Cardiology, Pulmonology, Hypertension and Nephrology, Graduate School of Medicine, Ehime University, Tohon, Ehime, Japan
| | - Masaki Mogi
- Department of Molecular Cardiovascular Biology and Pharmacology, Graduate School of Medicine, Ehime University, Tohon, Ehime, Japan
| | - Jun Iwanami
- Department of Molecular Cardiovascular Biology and Pharmacology, Graduate School of Medicine, Ehime University, Tohon, Ehime, Japan
| | - Li-Juan Min
- Department of Molecular Cardiovascular Biology and Pharmacology, Graduate School of Medicine, Ehime University, Tohon, Ehime, Japan
| | - Hui-Yu Bai
- Department of Molecular Cardiovascular Biology and Pharmacology, Graduate School of Medicine, Ehime University, Tohon, Ehime, Japan
| | - Bao-Shuai Shan
- Department of Molecular Cardiovascular Biology and Pharmacology, Graduate School of Medicine, Ehime University, Tohon, Ehime, Japan
| | - Masayoshi Kukida
- Department of Molecular Cardiovascular Biology and Pharmacology, Graduate School of Medicine, Ehime University, Tohon, Ehime, Japan.,Department of Cardiology, Pulmonology, Hypertension and Nephrology, Graduate School of Medicine, Ehime University, Tohon, Ehime, Japan
| | - Toshifumi Yamauchi
- Department of Pediatrics, Graduate School of Medicine, Ehime University, Tohon, Ehime, Japan
| | - Kana Tsukuda
- Department of Molecular Cardiovascular Biology and Pharmacology, Graduate School of Medicine, Ehime University, Tohon, Ehime, Japan
| | - Harumi Kan-No
- Department of Molecular Cardiovascular Biology and Pharmacology, Graduate School of Medicine, Ehime University, Tohon, Ehime, Japan
| | - Shuntaro Ikeda
- Department of Cardiology, Pulmonology, Hypertension and Nephrology, Graduate School of Medicine, Ehime University, Tohon, Ehime, Japan
| | - Jitsuo Higaki
- Department of Cardiology, Pulmonology, Hypertension and Nephrology, Graduate School of Medicine, Ehime University, Tohon, Ehime, Japan
| | - Masatsugu Horiuchi
- Department of Molecular Cardiovascular Biology and Pharmacology, Graduate School of Medicine, Ehime University, Tohon, Ehime, Japan
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