Aims/hypothesis  

Wingless and iNT-1 (WNT) pathway members are critical for pancreatic development and exocrine tissue formation. Recently, much attention has focused on delineating the roles of β-catenin in pancreatic organogenesis. However, little is known about the involvement of β-catenin in the endocrine or exocrine function of the mature pancreas. We report for the first time the impact of β-catenin deletion in the pancreatic beta cells.

Methods  

We targeted the deletion of the β-catenin gene in pancreatic beta cells by crossing a floxed β-catenin mouse strain with a RIP-Cre mouse strain.

Results  

Surprisingly, the majority of the mutant mice died shortly after birth and had deregulated glucose and insulin levels. The newborn mutant pancreases demonstrated increased insulin content, reflecting a defect in insulin release confirmed in vitro. Moreover, there was a reduction in total endocrine tissue at birth, while cellularity in islets was greater, suggesting that lack of β-catenin affects beta cell size. Some newborns survived β-catenin deletion and showed a milder phenotype during adulthood.

Conclusions/interpretation  

The deletion of β-catenin in the maturing beta cells negatively impacts on islet morphology and function. This work reveals that lack of β-catenin in early life is related to severe deregulation of glucose homeostasis.