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Ablation of the androgen receptor from vascular smooth muscle cells demonstrates a role for testosterone in vascular calcification.

Zhu D, Hadoke PW, Wu J, Vesey AT, Lerman DA, Dweck MR, Newby DE, Smith LB, MacRae VE - Sci Rep (2016)

Bottom Line: Testosterone-induced calcification was blunted in VSMC-specific AR-ablated (SM-ARKO) VSMCs compared to WT.Consistent with these data, SM-ARKO VSMCs showed a reduction in Osterix mRNA expression.Androgen signalling may represent a novel potential therapeutic target for clinical intervention.

View Article: PubMed Central - PubMed

Affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, EH25 9RG, UK.

ABSTRACT
Vascular calcification powerfully predicts mortality and morbidity from cardiovascular disease. Men have a greater risk of cardiovascular disease, compared to women of a similar age. These gender disparities suggest an influence of sex hormones. Testosterone is the primary and most well-recognised androgen in men. Therefore, we addressed the hypothesis that exogenous androgen treatment induces vascular calcification. Immunohistochemical analysis revealed expression of androgen receptor (AR) in the calcified media of human femoral artery tissue and calcified human valves. Furthermore, in vitro studies revealed increased phosphate (Pi)-induced mouse vascular smooth muscle cell (VSMC) calcification following either testosterone or dihydrotestosterone (DHT) treatment for 9 days. Testosterone and DHT treatment increased tissue non-specific alkaline phosphatase (Alpl) mRNA expression. Testosterone-induced calcification was blunted in VSMC-specific AR-ablated (SM-ARKO) VSMCs compared to WT. Consistent with these data, SM-ARKO VSMCs showed a reduction in Osterix mRNA expression. However, intriguingly, a counter-intuitive increase in Alpl was observed. These novel data demonstrate that androgens play a role in inducing vascular calcification through the AR. Androgen signalling may represent a novel potential therapeutic target for clinical intervention.

No MeSH data available.


Related in: MedlinePlus

Androgens promote VSMC calcification and regulate osteogenic gene expression.VSMCs were cultured with high phosphate (3 mM Pi; filled bar) or control (1 mM Pi; white bar) for up to 9 days. Calcium content (μg/mg protein) of cells treated with (a) testosterone (1–100 nM) (n = 4) or (b) DHT (1-100 nM) (n = 4). Fold change in the mRNA expression of (c) Alpl (d) Osterix and (e) Mgp following 48 hr treatment with testosterone (white bar) or DHT (filled bar) (n = 6). Results are presented as mean +/− S.E.M *P < 0.05; **P < 0.01; ***P < 0.001 compared with control.
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f2: Androgens promote VSMC calcification and regulate osteogenic gene expression.VSMCs were cultured with high phosphate (3 mM Pi; filled bar) or control (1 mM Pi; white bar) for up to 9 days. Calcium content (μg/mg protein) of cells treated with (a) testosterone (1–100 nM) (n = 4) or (b) DHT (1-100 nM) (n = 4). Fold change in the mRNA expression of (c) Alpl (d) Osterix and (e) Mgp following 48 hr treatment with testosterone (white bar) or DHT (filled bar) (n = 6). Results are presented as mean +/− S.E.M *P < 0.05; **P < 0.01; ***P < 0.001 compared with control.

Mentions: To investigate the role of the AR in VSMCs, we examined the effects of androgens on VSMC calcification. Initial studies examined whether androgens directly regulate the osteogenic differentiation and calcification of VSMCs. Since arterial calcification is highly correlated with elevated serum Pi levels, VSMCs were cultured in growth medium containing high Pi (3 mM) as previously described3334. Cells were treated with 1–100 nM testosterone or DHT in the presence or absence of high Pi medium for up to 9 days. A minimum concentration of 10 nM testosterone treatment significantly increased calcium deposition of VSMCs at 9 days, as evaluated by HCl leaching (1.8 fold, P < 0.01, Fig. 2a). A minimum concentration of 100 nM DHT treatment significantly increased calcium deposition in VSMCs at 9 days (1.6 fold, P < 0.05, Fig. 2b). Testosterone and DHT (100 nM) induced a significant increase in the mRNA expression of Alpl a key mediator of mineralisation (1.14 fold, P < 0.01) (Fig. 2c). No change in the mRNA expression of the osteogenic marker Osterix or the mineralisation inhibitor Mgp was observed (Fig. 2d,e).


Ablation of the androgen receptor from vascular smooth muscle cells demonstrates a role for testosterone in vascular calcification.

Zhu D, Hadoke PW, Wu J, Vesey AT, Lerman DA, Dweck MR, Newby DE, Smith LB, MacRae VE - Sci Rep (2016)

Androgens promote VSMC calcification and regulate osteogenic gene expression.VSMCs were cultured with high phosphate (3 mM Pi; filled bar) or control (1 mM Pi; white bar) for up to 9 days. Calcium content (μg/mg protein) of cells treated with (a) testosterone (1–100 nM) (n = 4) or (b) DHT (1-100 nM) (n = 4). Fold change in the mRNA expression of (c) Alpl (d) Osterix and (e) Mgp following 48 hr treatment with testosterone (white bar) or DHT (filled bar) (n = 6). Results are presented as mean +/− S.E.M *P < 0.05; **P < 0.01; ***P < 0.001 compared with control.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4837411&req=5

f2: Androgens promote VSMC calcification and regulate osteogenic gene expression.VSMCs were cultured with high phosphate (3 mM Pi; filled bar) or control (1 mM Pi; white bar) for up to 9 days. Calcium content (μg/mg protein) of cells treated with (a) testosterone (1–100 nM) (n = 4) or (b) DHT (1-100 nM) (n = 4). Fold change in the mRNA expression of (c) Alpl (d) Osterix and (e) Mgp following 48 hr treatment with testosterone (white bar) or DHT (filled bar) (n = 6). Results are presented as mean +/− S.E.M *P < 0.05; **P < 0.01; ***P < 0.001 compared with control.
Mentions: To investigate the role of the AR in VSMCs, we examined the effects of androgens on VSMC calcification. Initial studies examined whether androgens directly regulate the osteogenic differentiation and calcification of VSMCs. Since arterial calcification is highly correlated with elevated serum Pi levels, VSMCs were cultured in growth medium containing high Pi (3 mM) as previously described3334. Cells were treated with 1–100 nM testosterone or DHT in the presence or absence of high Pi medium for up to 9 days. A minimum concentration of 10 nM testosterone treatment significantly increased calcium deposition of VSMCs at 9 days, as evaluated by HCl leaching (1.8 fold, P < 0.01, Fig. 2a). A minimum concentration of 100 nM DHT treatment significantly increased calcium deposition in VSMCs at 9 days (1.6 fold, P < 0.05, Fig. 2b). Testosterone and DHT (100 nM) induced a significant increase in the mRNA expression of Alpl a key mediator of mineralisation (1.14 fold, P < 0.01) (Fig. 2c). No change in the mRNA expression of the osteogenic marker Osterix or the mineralisation inhibitor Mgp was observed (Fig. 2d,e).

Bottom Line: Testosterone-induced calcification was blunted in VSMC-specific AR-ablated (SM-ARKO) VSMCs compared to WT.Consistent with these data, SM-ARKO VSMCs showed a reduction in Osterix mRNA expression.Androgen signalling may represent a novel potential therapeutic target for clinical intervention.

View Article: PubMed Central - PubMed

Affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, EH25 9RG, UK.

ABSTRACT
Vascular calcification powerfully predicts mortality and morbidity from cardiovascular disease. Men have a greater risk of cardiovascular disease, compared to women of a similar age. These gender disparities suggest an influence of sex hormones. Testosterone is the primary and most well-recognised androgen in men. Therefore, we addressed the hypothesis that exogenous androgen treatment induces vascular calcification. Immunohistochemical analysis revealed expression of androgen receptor (AR) in the calcified media of human femoral artery tissue and calcified human valves. Furthermore, in vitro studies revealed increased phosphate (Pi)-induced mouse vascular smooth muscle cell (VSMC) calcification following either testosterone or dihydrotestosterone (DHT) treatment for 9 days. Testosterone and DHT treatment increased tissue non-specific alkaline phosphatase (Alpl) mRNA expression. Testosterone-induced calcification was blunted in VSMC-specific AR-ablated (SM-ARKO) VSMCs compared to WT. Consistent with these data, SM-ARKO VSMCs showed a reduction in Osterix mRNA expression. However, intriguingly, a counter-intuitive increase in Alpl was observed. These novel data demonstrate that androgens play a role in inducing vascular calcification through the AR. Androgen signalling may represent a novel potential therapeutic target for clinical intervention.

No MeSH data available.


Related in: MedlinePlus