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A sex-specific role for androgens in angiogenesis.

Sieveking DP, Lim P, Chow RW, Dunn LL, Bao S, McGrath KC, Heather AK, Handelsman DJ, Celermajer DS, Ng MK - J. Exp. Med. (2010)

Bottom Line: Androgen receptor (AR) antagonism or gene knockdown abrogated these effects in male ECs.In vivo, castration dramatically reduced neovascularization of Matrigel plugs.Androgen treatment fully reversed this effect in male mice but had no effect in female mice.

View Article: PubMed Central - HTML - PubMed

Affiliation: Heart Research Institute, Sydney 2042, Australia. sievekingd@hri.org.au

ABSTRACT
Mounting evidence suggests that in men, serum levels of testosterone are negatively correlated to cardiovascular and all-cause mortality. We studied the role of androgens in angiogenesis, a process critical in cardiovascular repair/regeneration, in males and females. Androgen exposure augmented key angiogenic events in vitro. Strikingly, this occurred in male but not female endothelial cells (ECs). Androgen receptor (AR) antagonism or gene knockdown abrogated these effects in male ECs. Overexpression of AR in female ECs conferred androgen sensitivity with respect to angiogenesis. In vivo, castration dramatically reduced neovascularization of Matrigel plugs. Androgen treatment fully reversed this effect in male mice but had no effect in female mice. Furthermore, orchidectomy impaired blood-flow recovery from hindlimb ischemia, a finding rescued by androgen treatment. Our findings suggest that endogenous androgens modulate angiogenesis in a sex-dependent manner, with implications for the role of androgen replacement in men.

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Proangiogenic effects of DHT in male ECs is VEGF dependent. (A) Production of VEGF by male ECs exposed to DHT for 48 h. Total cell lysate protein was quantified and assayed via ELISA (n = 4 independent experiments). P = 0.002 using ANOVA for linear trend. (B) Expression of Flt-1 (P = 0.0128) and (C) KDR (P = 0.0295) mRNA and (D) Flt-1 and (E) KDR (P = 0.0005) protein in male ECs exposed to DHT for 48 h (using ANOVA for linear trend). (F) Vascular network formation in male ECs treated with DHT with and without 1 µg/ml anti-VEGF antibody or 10 µM of the PI3K inhibitor LY294002 (n = 3 independent experiments for B–F, respectively). ***, P < 0.001 compared with control using ANOVA. All data are expressed as means ± SEM. For each independent experiment, cells from a different donor were used.
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fig3: Proangiogenic effects of DHT in male ECs is VEGF dependent. (A) Production of VEGF by male ECs exposed to DHT for 48 h. Total cell lysate protein was quantified and assayed via ELISA (n = 4 independent experiments). P = 0.002 using ANOVA for linear trend. (B) Expression of Flt-1 (P = 0.0128) and (C) KDR (P = 0.0295) mRNA and (D) Flt-1 and (E) KDR (P = 0.0005) protein in male ECs exposed to DHT for 48 h (using ANOVA for linear trend). (F) Vascular network formation in male ECs treated with DHT with and without 1 µg/ml anti-VEGF antibody or 10 µM of the PI3K inhibitor LY294002 (n = 3 independent experiments for B–F, respectively). ***, P < 0.001 compared with control using ANOVA. All data are expressed as means ± SEM. For each independent experiment, cells from a different donor were used.

Mentions: Next, to further elucidate the means by which DHT augmented migration, proliferation, and tubulogenesis in male ECs, cells exposed to DHT were assessed for the expression of various proangiogenic factors. Exposure of male ECs to DHT produced a dose-dependent increase in the production of VEGF, a key angiogenic growth factor (102.8 ± 7, 107.8 ± 7, 118.9 ± 6, and 147.2 ± 15 pg VEGF/100 µg of cell protein for 0, 4, 40, and 400 nM DHT, respectively; P = 0.0024; Fig. 3 A). Similarly, DHT induced dose-dependent increases in the messenger RNA (mRNA) expression of VEGF receptors 1 and 2 (Flt-1 and KDR, respectively; Fig. 3, B and C). However, flow cytometric assessment of surface VEGF receptor levels revealed that DHT augmented KDR but not Flt-1 expression in a dose-dependent manner (Fig. 3, D and E). As KDR is the chief mediator of the mitogenic/angiogenic action of VEGF in ECs, whereas Flt-1 may function as a negative regulator of VEGF action (Ferrara et al., 2003), our findings are consistent with a proangiogenic role for DHT through VEGF signaling via KDR. Furthermore, the addition of anti-VEGF antibody abrogated DHT-mediated increases in tubulogenesis (Fig. 3 F). Likewise, LY294002, an inhibitor of phosphoinositol 3-kinase (PI3K), a key enzyme in the PI3K–AKT pathway of VEGF signaling, inhibited DHT-mediated tubulogenesis (Fig. 3 F). These findings suggest that the proangiogenic effects of DHT in male ECs are VEGF dependent.


A sex-specific role for androgens in angiogenesis.

Sieveking DP, Lim P, Chow RW, Dunn LL, Bao S, McGrath KC, Heather AK, Handelsman DJ, Celermajer DS, Ng MK - J. Exp. Med. (2010)

Proangiogenic effects of DHT in male ECs is VEGF dependent. (A) Production of VEGF by male ECs exposed to DHT for 48 h. Total cell lysate protein was quantified and assayed via ELISA (n = 4 independent experiments). P = 0.002 using ANOVA for linear trend. (B) Expression of Flt-1 (P = 0.0128) and (C) KDR (P = 0.0295) mRNA and (D) Flt-1 and (E) KDR (P = 0.0005) protein in male ECs exposed to DHT for 48 h (using ANOVA for linear trend). (F) Vascular network formation in male ECs treated with DHT with and without 1 µg/ml anti-VEGF antibody or 10 µM of the PI3K inhibitor LY294002 (n = 3 independent experiments for B–F, respectively). ***, P < 0.001 compared with control using ANOVA. All data are expressed as means ± SEM. For each independent experiment, cells from a different donor were used.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC2822613&req=5

fig3: Proangiogenic effects of DHT in male ECs is VEGF dependent. (A) Production of VEGF by male ECs exposed to DHT for 48 h. Total cell lysate protein was quantified and assayed via ELISA (n = 4 independent experiments). P = 0.002 using ANOVA for linear trend. (B) Expression of Flt-1 (P = 0.0128) and (C) KDR (P = 0.0295) mRNA and (D) Flt-1 and (E) KDR (P = 0.0005) protein in male ECs exposed to DHT for 48 h (using ANOVA for linear trend). (F) Vascular network formation in male ECs treated with DHT with and without 1 µg/ml anti-VEGF antibody or 10 µM of the PI3K inhibitor LY294002 (n = 3 independent experiments for B–F, respectively). ***, P < 0.001 compared with control using ANOVA. All data are expressed as means ± SEM. For each independent experiment, cells from a different donor were used.
Mentions: Next, to further elucidate the means by which DHT augmented migration, proliferation, and tubulogenesis in male ECs, cells exposed to DHT were assessed for the expression of various proangiogenic factors. Exposure of male ECs to DHT produced a dose-dependent increase in the production of VEGF, a key angiogenic growth factor (102.8 ± 7, 107.8 ± 7, 118.9 ± 6, and 147.2 ± 15 pg VEGF/100 µg of cell protein for 0, 4, 40, and 400 nM DHT, respectively; P = 0.0024; Fig. 3 A). Similarly, DHT induced dose-dependent increases in the messenger RNA (mRNA) expression of VEGF receptors 1 and 2 (Flt-1 and KDR, respectively; Fig. 3, B and C). However, flow cytometric assessment of surface VEGF receptor levels revealed that DHT augmented KDR but not Flt-1 expression in a dose-dependent manner (Fig. 3, D and E). As KDR is the chief mediator of the mitogenic/angiogenic action of VEGF in ECs, whereas Flt-1 may function as a negative regulator of VEGF action (Ferrara et al., 2003), our findings are consistent with a proangiogenic role for DHT through VEGF signaling via KDR. Furthermore, the addition of anti-VEGF antibody abrogated DHT-mediated increases in tubulogenesis (Fig. 3 F). Likewise, LY294002, an inhibitor of phosphoinositol 3-kinase (PI3K), a key enzyme in the PI3K–AKT pathway of VEGF signaling, inhibited DHT-mediated tubulogenesis (Fig. 3 F). These findings suggest that the proangiogenic effects of DHT in male ECs are VEGF dependent.

Bottom Line: Androgen receptor (AR) antagonism or gene knockdown abrogated these effects in male ECs.In vivo, castration dramatically reduced neovascularization of Matrigel plugs.Androgen treatment fully reversed this effect in male mice but had no effect in female mice.

View Article: PubMed Central - HTML - PubMed

Affiliation: Heart Research Institute, Sydney 2042, Australia. sievekingd@hri.org.au

ABSTRACT
Mounting evidence suggests that in men, serum levels of testosterone are negatively correlated to cardiovascular and all-cause mortality. We studied the role of androgens in angiogenesis, a process critical in cardiovascular repair/regeneration, in males and females. Androgen exposure augmented key angiogenic events in vitro. Strikingly, this occurred in male but not female endothelial cells (ECs). Androgen receptor (AR) antagonism or gene knockdown abrogated these effects in male ECs. Overexpression of AR in female ECs conferred androgen sensitivity with respect to angiogenesis. In vivo, castration dramatically reduced neovascularization of Matrigel plugs. Androgen treatment fully reversed this effect in male mice but had no effect in female mice. Furthermore, orchidectomy impaired blood-flow recovery from hindlimb ischemia, a finding rescued by androgen treatment. Our findings suggest that endogenous androgens modulate angiogenesis in a sex-dependent manner, with implications for the role of androgen replacement in men.

Show MeSH
Related in: MedlinePlus