title: Expression of TMEM16A and SLC4A4 in human pancreatic islets.
abstract: OBJECTIVE
  Stimulation of insulin release by D-glucose is accompanied by Cl(-) and HCO(3)(-) efflux from pancreatic islet cells. The efflux of these anions may involve volume-regulated anion channels, including possibly TMEM16A, and the Na(+)-HCO(3)(-)-cotransporter SLC4A4. The present study was designed to explore the expression of both TMEM16A and SLC4A4 in human pancreatic islets.
  
  
  METHODS
  Pancreases were obtained from human cadaveric donors. Immunodetection of TMEM16A and SLC4A4 was performed by immunohistochemistry on sections of fixed pancreas, while real-time PCR for the study of corresponding gene expression was performed on RNA extracted from both total pancreatic pieces and isolated pancreatic islets.
  
  
  RESULTS
  RT-PCR yielded lower levels of SLC4A4 in isolated islets than in the total pancreas, whilst a mirror image prevailed for TMEM16A mRNA. Immunohistochemistry of human pancreas, however, indicated comparable immunostaining of SLC4A4 in insulin-producing cells and exocrine pancreatic cells, whilst that of TMEM16A appeared less pronounced in insulin-producing cells than in exocrine cells.
  
  
  CONCLUSIONS
  The present findings support the view that, in humans like in rodent, the regulation of anion fluxes in insulin-producing cells may involve both SLC4A4 and TMEM16A.
authors.affiliation: Laboratory of Diabetes and Obesity IDIBAPS, CIBERDEM, Department of Endocrinology and Nutrition, Hospital Clinic, Barcelona, Spain. fhanzu@clinic.ub.es
authors.forename: Felicia A
authors.initials: FA
authors.lastname: Hanzu
authors.forename: Rosa
authors.initials: R
authors.lastname: Gasa
authors.forename: Nurdan
authors.initials: N
authors.lastname: Bulur
authors.forename: Pascale
authors.initials: P
authors.lastname: Lybaert
authors.forename: Ramon
authors.initials: R
authors.lastname: Gomis
authors.forename: Willy J
authors.initials: WJ
authors.lastname: Malaisse
authors.forename: Renaud
authors.initials: R
authors.lastname: Beauwens
authors.forename: Abdullah
authors.initials: A
authors.lastname: Sener
mesh_terms: D000818:Animals; D000075369:Anoctamin-1; D018118:Chloride Channels / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D007150:Immunohistochemistry; D007515:Islets of Langerhans / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D027982:Sodium-Bicarbonate Symporters / Q000235:genetics / Q000378:metabolism*
chemical_list: C476213:ANO1 protein, human; D000075369:Anoctamin-1; D018118:Chloride Channels; D009363:Neoplasm Proteins; D012333:RNA, Messenger; C498898:SLC4A4 protein, human; D027982:Sodium-Bicarbonate Symporters