title: Dual regulatory role for phosphatase and tensin homolog in specification of intestinal endocrine cell subtypes.
abstract: OBJECTIVE
  To investigate the impact of phosphatase and tensin homolog (Pten) in the specification of intestinal enteroendocrine subpopulations.
  
  
  METHODS
  Using the Cre/loxP system, a mouse with conditional intestinal epithelial Pten deficiency was generated. Pten mutant mice and controls were sacrificed and small intestines collected for immunofluorescence and quantitative real-time polymerase chain reaction. Blood was collected on 16 h fasted mice by cardiac puncture. Enzyme-linked immunosorbent assay was used to measure blood circulating ghrelin, somatostatin (SST) and glucose-dependent insulinotropic peptide (GIP) levels.
  
  
  RESULTS
  Results show an unexpected dual regulatory role for epithelial Pten signalling in the specification/differentiation of enteroendocrine cell subpopulations in the small intestine. Our data indicate that Pten positively regulates chromogranin A (CgA) expressing subpopulations, including cells expressing secretin, ghrelin, gastrin and cholecystokinin (CCK). In contrast, Pten negatively regulates the enteroendocrine subtype specification of non-expressing CgA cells such as GIP and SST expressing cells.
  
  
  CONCLUSIONS
  The present results demonstrate that Pten signalling favours the enteroendocrine progenitor to specify into cells expressing CgA including those producing CCK, gastrin and ghrelin.
authors.affiliation: Canadian Institutes of Health Research Team on Digestive Epithelium, Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke J1H 5N4, QC, Canada.
authors.forename: Sébastien A B
authors.initials: SA
authors.lastname: Roy
authors.forename: Marie-Josée
authors.initials: MJ
authors.lastname: Langlois
authors.forename: Julie C
authors.initials: JC
authors.lastname: Carrier
authors.forename: François
authors.initials: F
authors.lastname: Boudreau
authors.forename: Nathalie
authors.initials: N
authors.lastname: Rivard
authors.forename: Nathalie
authors.initials: N
authors.lastname: Perreault
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D053379:Chromogranin A / Q000378:metabolism*; D019858:Enteroendocrine Cells / Q000166:cytology*; D005749:Gastric Inhibitory Polypeptide / Q000378:metabolism; D020869:Gene Expression Profiling; D054439:Ghrelin / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000166:cytology*; D051379:Mice; D008822:Mice, Transgenic; D051059:PTEN Phosphohydrolase / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D053379:Chromogranin A; D054439:Ghrelin; D012333:RNA, Messenger; C506155:chromogranin A, mouse; D005749:Gastric Inhibitory Polypeptide; D051059:PTEN Phosphohydrolase; C487757:Pten protein, mouse