T.F. Glis3: a novel critical player in the regulation of pancreatic beta-cell development and insulin gene expression. Mus musculus

Glis3 mutant mice (Glis3zf/zf) die within the first week after birth due to overt diabetes, evidenced by hyperglycemia and hypoinsulinemia. Histopathological analysis showed that Glis3zf/zf mice develop a pancreatic phenotype with a dramatic loss of beta- (insulin) and delta- (somatostatin) cells contrasting a smaller relative loss of alpha- (glucagon), PP- (pancreatic polypeptide), and epsilon- (ghrelin) cells. Glis3zf/zf mice develop ductal cysts with decreased number of primary cilia, while the acini are not significantly affected. Gene expression profiling by microarray analysis demonstrated that the expression of terminal hormonal genes and several transcription factors important in endocrine development were significantly deregulated in Glis3zf/zf mice. During pancreatic development, Glis3 mRNA expression is induced during the secondary transition, a stage of cell lineage specification and extensive patterning. Changes in pancreatic development of Glis3zf/zf mice are noted during and after this stage. The population of pancreatic progenitors appears not to be greatly affected in Glis3zf/zf mice; however, the number of neurogenin 3 (Ngn3) positive, endocrine progenitors is significantly reduced. Our study indicates that Glis3 plays a key role in cell lineage specification, particularly the development of mature pancreatic beta-cells. In addition, we identified evidence that Glis3 regulates insulin gene expression through two Glis-binding sites in its proximal promoter indicating that Glis3 is a regulator of insulin gene expression. Overall design: For E15.5 microarray, RNAs were purified from 3 of WT and 4 of Glis3zf/zf pancreas and applied on Affymetrix chip. For postnatal day 3 (PND3) analysis RNA samples from 2 pups of for each WT or Glis3zf/zf pups were pooled, then analyzed.