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Age (Dordr). 2016 Jun;38(3):60. doi: 10.1007/s11357-016-9910-5. Epub 2016 May 20.

Testosterone delays vascular smooth muscle cell senescence and inhibits collagen synthesis via the Gas6/Axl signaling pathway.

Author information

1
The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health; The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital of Shandong University, NO.107, Wen Hua Xi Road, Ji'nan, 250012, People's Republic of China.
2
Department of Cardiology, Central Hospital of Zibo, Zibo, People's Republic of China.
3
The Department of Emergency Medicine, Qilu Hospital of Shandong University, Ji'nan, People's Republic of China.
4
Department of Geriatrics, Qilu Hospital of Shandong University, Ji'nan, People's Republic of China.
5
The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health; The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital of Shandong University, NO.107, Wen Hua Xi Road, Ji'nan, 250012, People's Republic of China. lili_8599@163.com.
6
The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health; The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital of Shandong University, NO.107, Wen Hua Xi Road, Ji'nan, 250012, People's Republic of China. zhongmingzm@gmail.com.

Abstract

Testosterone deficiency is associated with a higher incidence of cardiovascular diseases in men. However, its effect on cell senescence, which plays a causal role in vascular aging, remains unclear. Here, we tested the hypothesis that testosterone alleviated vascular smooth muscle cell (VSMC) senescence and collagen synthesis via growth arrest-specific protein 6 (Gas6)/Axl- and Akt/FoxO1a-dependent pathways. Testosterone significantly ameliorated angiotensin II-induced VSMC senescence and collagen overexpression. In addition, testosterone inhibited angiotensin II-induced matrix metalloproteinase-2 (MMP-2) activity, which played a pivotal role in facilitating age-related collagen deposition. Testosterone increased the expression of tissue inhibitor of metalloproteinase-2 but decreased the expression of MMP-2 and membrane type-1 metalloproteinase which contributed to increase MMP-2 activity. The effects on VSMCs senescence and collagen synthesis were mediated by restoration of angiotensin II-induced downregulation of Gas6 and Axl expression and a subsequent reduction of Akt and FoxO1a phosphorylation. The effects of testosterone were reversed by a Gas6 blocker, Axl-Fc, and a specific inhibitor of Axl, R428. Treatment of VSMCs with PI3K inhibitor LY294002 abrogated the downregulating effect of testosterone on MMP-2 activity. Furthermore, when FoxO1a expression was silenced by using a specific siRNA, the inhibitory effect of testosterone on MMP-2 activity was revered as well, that indicated this process was Akt/FoxO1a dependence. Taken together, Gas6/Axl and Akt/FoxO1a were involved in protective effects of testosterone on VSMCs senescence and collagen synthesis. Our results provide a novel mechanism underlying the protective effect of testosterone on vascular aging and may serve as a theoretical basis for testosterone replacement therapy.

KEYWORDS:

Cellular senescence; Collagen; Growth arrest-specific protein 6 (Gas6)/Axl; Testosterone; Vascular smooth muscle cell

PMID:
27206970
PMCID:
PMC5005950
DOI:
10.1007/s11357-016-9910-5
[Indexed for MEDLINE]
Free PMC Article

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