Phosphorylation of murine double minute-2 on Ser166 is downstream of VEGF-A in exercised skeletal muscle and regulates primary endothelial cell migration and FoxO gene expression.
FASEB J
; 30(3): 1120-34, 2016 Mar.
Article
em En
| MEDLINE
| ID: mdl-26578686
ABSTRACT
We demonstrated in a previous study that murine double minute (Mdm)-2 is essential for exercise-induced skeletal muscle angiogenesis. In the current study, we investigated the mechanisms that regulate Mdm2 activity in response to acute exercise and identified VEGF-A as a key stimulator of Mdm2 phosphorylation on Ser(166) (p-Ser166-Mdm2). VEGF-A and p-Ser166-Mdm2 protein levels were measured in human and rodent muscle biopsy specimens after 1 bout of exercise. VEGF-A-dependent Mdm2 phosphorylation was demonstrated in vivo in mice harboring myofiber-specific deletion of VEGF-A (mVEGF(-/-)) and in vitro in primary human and rodent endothelial cells (ECs). Exercise increased VEGF-A and p-Ser166-Mdm2 protein levels respectively by 157 and 68% in human muscle vs. pre-exercise levels. Similar results were observed in exercised rodent muscles compared to sedentary controls; however, exercise-induced Mdm2 phosphorylation was significantly attenuated in mVEGF(-/-) mice. Recombinant VEGF-A elevated p-Ser166-Mdm2 by 50-125% and stimulated migration by 33% in ECs when compared to untreated cells, whereas the Mdm2 antagonist Nutlin-3a abrogated VEGF-driven EC migration. Finally, overexpression of a Ser166-Mdm2 phosphorylation mimetic increased EC migration, increased Mdm2 to FoxO1 binding (+55%), and decreased FoxO1-dependent gene expression compared with ECs overexpressing WT-Mdm2. Our results suggest that VEGF-mediated Mdm2 phosphorylation on Ser(166) is a novel proangiogenic pathway within the skeletal muscle.
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Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Condicionamento Físico Animal
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Movimento Celular
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Músculo Esquelético
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Células Endoteliais
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Fator A de Crescimento do Endotélio Vascular
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Proteínas Proto-Oncogênicas c-mdm2
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Fatores de Transcrição Forkhead
Tipo de estudo:
Prognostic_studies
Limite:
Animals
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Female
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Humans
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Male
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article