Hypothalamic ependymal-glial cells express the glucose transporter GLUT2, a protein involved in glucose sensing

María De los Angeles García, Carola Millán, Carolina Balmaceda-Aguilera, Tamara Castro, Patricia Pastor, Hemán Montecinos, Karin Reinicke, Felipe Zúñiga, Juan Carlos Vera, Sergio A. Oñate, Francisco Nualart

Research output: Contribution to journalArticlepeer-review

162 Scopus citations

Abstract

The GLUT2 glucose transporter and the K-ATP-sensitive potassium channels have been implicated as an integral part of the glucose-sensing mechanism in the pancreatic islet β cells. The expression of GLUT2 and K-ATP channels in the hypothalamic region suggest that they are also involved in a sensing mechanism in this area. The hypothalamic glial cells, known as tanycytes α and β, are specialized ependymal cells that bridge the cerebrospinal fluid and the portal blood of the median eminence. We used immunocytochemistry, in situ hybridization and transport analyses to demonstrate the glucose transporters expressed in tanycytes. Confocal microscopy using specific antibodies against GLUT1 and GLUT2 indicated that both transporters are expressed in α and β tanycytes. In addition, primary cultures of mouse hypothalamic tanycytes were found to express both GLUT1 and GLUT2 transporters. Transport studies, including 2-deoxyglucose and fructose uptake in the presence or absence of inhibitors, indicated that these transporters are functional in cultured tanycytes. Finally, our analyses indicated that tanycytes express the K-ATP channel subunit Kir6.1 in vitro. As the expression of GLUT2 and K-ATP channel is linked to glucose-sensing mechanisms in pancreatic β cells, we postulate that tanycytes may be responsible, at least in part, for a mechanism that allows the hypothalamus to detect changes in glucose concentrations.

Original languageEnglish
Pages (from-to)709-724
Number of pages16
JournalJournal of Neurochemistry
Volume86
Issue number3
DOIs
StatePublished - Aug 2003

Keywords

  • Glia
  • Glucose sensing
  • Glucose transporter 2
  • Hypothalamus
  • K-ATP-sensitive potassium channels
  • Tanycytes

Fingerprint

Dive into the research topics of 'Hypothalamic ependymal-glial cells express the glucose transporter GLUT2, a protein involved in glucose sensing'. Together they form a unique fingerprint.

Cite this