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Ex Vivo and In Vivo Regulation of Lipocalin-2, a Novel Adipokine, by Insulin
OBJECTIVE—Lipocalin-2, a novel adipokine, has been shown to be elevated in obese, insulin-resistant, and diabetic subjects. We therefore sought to study the ex vivo and in vivo effects of insulin on lipocalin-2 levels in humans. RESEARCH DESIGN AND METHODS—We investigated the in vivo effects of insu...
Autores principales: | , , , , , , |
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Formato: | Texto |
Lenguaje: | English |
Publicado: |
American Diabetes Association
2009
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2606846/ https://www.ncbi.nlm.nih.gov/pubmed/18852336 http://dx.doi.org/10.2337/dc08-1236 |
Sumario: | OBJECTIVE—Lipocalin-2, a novel adipokine, has been shown to be elevated in obese, insulin-resistant, and diabetic subjects. We therefore sought to study the ex vivo and in vivo effects of insulin on lipocalin-2 levels in humans. RESEARCH DESIGN AND METHODS—We investigated the in vivo effects of insulin (hyperinsulinemia) on circulating lipocalin-2 levels by enzyme-linked immunosorbent assay via a prolonged insulin-glucose infusion. The ex vivo effect of insulin on adipose tissue lipocalin-2 protein production and secretion into conditioned media was assessed by Western blotting and enzyme-linked immunosorbent assay, respectively. RESULTS—Hyperinsulinemic induction in human subjects significantly increased circulating lipocalin-2 levels (P < 0.01). Also, in omental adipose tissue explants, insulin caused a significant dose-dependent increase in lipocalin-2 protein production and secretion into conditioned media (P < 0.05, P < 0.01, respectively); these effects were negated by both phosphatidylinositol 3-kinase and mitogen-activated protein kinase kinase inhibitors. CONCLUSIONS—Lipocalin-2 is upregulated by insulin via phosphatidylinositol 3-kinase and mitogen-activated protein kinase signaling pathways. |
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