Expression of TMEM16A and SLC4A4 in human pancreatic islets

Cell Physiol Biochem. 2012;29(1-2):61-4. doi: 10.1159/000337587. Epub 2012 Mar 1.

Abstract

Background/aims: 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.

Conclusion: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anoctamin-1
  • Chloride Channels / genetics
  • Chloride Channels / metabolism*
  • Gene Expression Regulation*
  • Humans
  • Immunohistochemistry
  • Islets of Langerhans / metabolism*
  • Islets of Langerhans / pathology
  • Mice
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism*
  • RNA, Messenger / metabolism
  • Sodium-Bicarbonate Symporters / genetics
  • Sodium-Bicarbonate Symporters / metabolism*

Substances

  • ANO1 protein, human
  • Anoctamin-1
  • Chloride Channels
  • Neoplasm Proteins
  • RNA, Messenger
  • SLC4A4 protein, human
  • Sodium-Bicarbonate Symporters