Cellular origins of adult human islet in vitro dedifferentiation.
Lab Invest
; 88(7): 761-72, 2008 Jul.
Article
en En
| MEDLINE
| ID: mdl-18490899
ABSTRACT
Cultured human islets can be dedifferentiated to duct-like structures composed mainly of cytokeratin+ and nestin+ cells. Given that these structures possess the potential to redifferentiate into islet-like structures, we sought to elucidate their specific cellular origins. Adenoviral vectors were engineered for beta-, alpha-, delta- or PP-cell-specific GFP expression. A double-stranded system was designed whereby cultures were infected with two vectors one expressed GFP behind the cumate-inducible promoter sequence, and the other expressed the requisite transactivator behind the human insulin, glucagon, somatostatin or pancreatic polypeptide promoter. This system labels hormone+ cells in the islet in a cell-specific manner, allowing these cells to be tracked during the course of transformation from islet to duct-like structure. Post-infection, islets were cultured to induce dedifferentiation. Fluorescence microscopy demonstrated that alpha-, delta- and PP-cells contributed equally to the cytokeratin+ population, with minimal beta-cell contribution, whereas the converse was true for nestin+ cells. Complementary targeted cell ablation studies, using streptozotocin or similar adenoviral expression of the Bax (Bcl2-associated X protein) toxigene, validated these findings and suggested a redundancy between alpha-, delta- and PP-cells with respect to cytokeratin+ cell derivation. These results call into question the traditional understanding of islet cells as being terminally differentiated and provide support for the concept of adult islet morphogenetic plasticity.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Islotes Pancreáticos
Límite:
Adult
/
Humans
Idioma:
En
Revista:
Lab Invest
Año:
2008
Tipo del documento:
Article
País de afiliación:
Canadá