MafB Is Critical for Glucagon Production and Secretion in Mouse Pancreatic α Cells In Vivo.
Mol Cell Biol
; 38(8)2018 04 15.
Article
em En
| MEDLINE
| ID: mdl-29378833
ABSTRACT
The MafB transcription factor is expressed in pancreatic α and ß cells during development but becomes exclusive to α cells in adult rodents. Mafb-null (Mafb-/- ) mice were reported to have reduced α- and ß-cell numbers throughout embryonic development. To further analyze the postnatal function of MafB in the pancreas, we generated endocrine cell-specific (MafbΔEndo ) and tamoxifen-dependent (MafbΔTAM ) Mafb knockout mice. MafbΔEndo mice exhibited reduced populations of insulin-positive (insulin+) and glucagon+ cells at postnatal day 0, but the insulin+ cell population recovered by 8 weeks of age. In contrast, the Arx+ glucagon+ cell fraction and glucagon expression remained decreased even in adulthood. MafbΔTAM mice, with Mafb deleted after pancreas maturation, also demonstrated diminished glucagon+ cells and glucagon content without affecting ß cells. A decreased Arx+ glucagon+ cell population in MafbΔEndo mice was compensated for by an increased Arx+ pancreatic polypeptide+ cell population. Furthermore, gene expression analyses from both MafbΔEndo and MafbΔTAM islets revealed that MafB is a key regulator of glucagon expression in α cells. Finally, both mutants failed to respond to arginine, likely due to impaired arginine transporter gene expression and glucagon production ability. Taken together, our findings reveal that MafB is critical for the functional maintenance of mouse α cells in vivo, including glucagon production and secretion, as well as in development.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Glucagon
/
Células Secretoras de Insulina
/
Fator de Transcrição MafB
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article