Glucose and hypothalamic astrocytes: More than a fueling role?
Neuroscience. 2016-05-01; 323: 110-120
DOI: 10.1016/j.neuroscience.2015.06.007
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Brain plays a central role in energy homeostasis continuously integrating
numerous peripheral signals such as circulating nutrients, and in particular
blood glucose level, a variable that must be highly regulated. Then, the brain
orchestrates adaptive responses to modulate food intake and peripheral organs
activity in order to achieve the fine tuning of glycemia. More than fifty years
ago, the presence of glucose-sensitive neurons was discovered in the
hypothalamus, but what makes them specific and identifiable still remains
disconnected from their electrophysiological signature. On the other hand,
astrocytes represent the major class of macroglial cells and are now recognized
to support an increasing number of neuronal functions. One of these functions
consists in the regulation of energy homeostasis through neuronal fueling and
nutrient sensing. Twenty years ago, we discovered that the glucose transporter
GLUT2, the canonical « glucosensor » of the pancreatic beta-cell together with the
glucokinase, was also present in astrocytes and participated in hypothalamic
glucose sensing. Since then, many studies have identified other actors and
emphasized the astroglial participation in this mechanism. Growing evidence
suggest that astrocytes form a complex network and have to be considered as
spatially coordinated and regulated metabolic units. In this review we aim to
provide an updated view of the molecular and respective cellular pathways
involved in hypothalamic glucose sensing, and their relevance in physiological
and pathological states.
Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.
DOI: 10.1016/j.neuroscience.2015.06.007
PMID: 26071958 [Indexed for MEDLINE]