Expression and distribution of Gpr119 in the pancreatic islets of mice and rats: Predominant localization in pancreatic polypeptide-secreting PP-cells

The GPR119 was recently shown to be activated by oleoylethanolamide (OEA), a naturally occurring bioactive lipid with hypophagic and anti-obesity effects. In this study, we have cloned and characterized its murine counterpart, Gpr119. The full-length cDNA contained an open reading frame of 1008 bp encoding a 335-amino acid protein. The genomic organization of Gpr119 was unique, having a 3′-untranslated second exon that was also involved in an alternative splicing event. Gene expression analyses confirmed its specific expressions in pancreatic islets and two endocrine cell-lines, MIN6 and αTC1. Immunohistochemistry and double-immunofluorescence studies using a specific antibody revealed the predominant Gpr119 localization in pancreatic polypeptide (PP)-cells of islets. No definitive evidence of Gpr119-immunoreactivity in adult β- or α-cells was obtained. The Gpr119 mRNA levels were elevated in islets of obese hyperglycemic db/db mice as compared to control islets, suggesting a possible involvement of this receptor in the development of obesity and diabetes.