A Pdx-1-Regulated Soluble Factor Activates Rat and Human Islet Cell Proliferation.
Mol Cell Biol
; 36(23): 2918-2930, 2016 12 01.
Article
en En
| MEDLINE
| ID: mdl-27620967
The homeodomain transcription factor Pdx-1 has important roles in pancreas and islet development as well as in ß-cell function and survival. We previously reported that Pdx-1 overexpression stimulates islet cell proliferation, but the mechanism remains unclear. Here, we demonstrate that overexpression of Pdx-1 triggers proliferation largely by a non-cell-autonomous mechanism mediated by soluble factors. Consistent with this idea, overexpression of Pdx-1 under the control of a ß-cell-specific promoter (rat insulin promoter [RIP]) stimulates proliferation of both α and ß cells, and overexpression of Pdx-1 in islets separated by a Transwell membrane from islets lacking Pdx-1 overexpression activates proliferation in the untreated islets. Microarray and gene ontology (GO) analysis identified inhibin beta-B (Inhbb), an activin subunit and member of the transforming growth factor ß (TGF-ß) superfamily, as a Pdx-1-responsive gene. Overexpression of Inhbb or addition of activin B stimulates rat islet cell and ß-cell proliferation, and the activin receptors RIIA and RIIB are required for the full proliferative effects of Pdx-1 in rat islets. In human islets, Inhbb overexpression stimulates total islet cell proliferation and potentiates Pdx-1-stimulated proliferation of total islet cells and ß cells. In sum, this study identifies a mechanism by which Pdx-1 induces a soluble factor that is sufficient to stimulate both rat and human islet cell proliferation.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Transactivadores
/
Islotes Pancreáticos
/
Proteínas de Homeodominio
/
Subunidades beta de Inhibinas
/
Insulina
Tipo de estudio:
Prognostic_studies
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Mol Cell Biol
Año:
2016
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos