Cooperative tanycytes fuel the neuronal tank
Roberta Haddad-Tóvolli, Marc Claret
Roberta Haddad-Tóvolli, Marc Claret
Published September 15, 2021
Citation Information: J Clin Invest. 2021;131(18):e153279. https://doi.org/10.1172/JCI153279.
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Commentary

Cooperative tanycytes fuel the neuronal tank

Abstract

Tanycytes are specialized radial glial cells of the hypothalamus that have emerged as important players that sense and respond to fluctuations in whole-body energy status to maintain energy homeostasis. However, the underlying mechanisms by which tanycytes influence energy balance remain incompletely understood. In this issue of the JCI, Lhomme et al. used transgenic mouse models, pharmacological approaches, and electrophysiology to investigate how tanycytes sense glucose availability and integrate metabolic cues into a lactate tanycytic network that fuels pro-opiomelanocortin (POMC) neuronal activity. Notably, the authors found that the tanycytic network relied on monocarboxylate transporters and connexin-43 gap junctions to transfer lactate to POMC neurons. Collectively, this study places tanycytes at the center of the intercellular communication processes governing energy balance.

Authors

Roberta Haddad-Tóvolli, Marc Claret

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Figure 1

Schematic illustration of the tanycytic lactate shuttle fueling POMC neuronal activity.

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Schematic illustration of the tanycytic lactate shuttle fueling POMC neu...
Tanycytes lining the 3V wall sense peripheral glucose levels and extend projections to the ARH parenchyma. The study by Lhomme et al. (3) shows that glucose sensing in tanycytes (brown cells) is translated into a lactate signaling pool that travels throughout a tanycytic network via Cx43 gap junctions to magnify metabolic signaling efficiency. Lactate is transmitted via MCTs to POMC neurons, where it is converted to energy (ATP) to induce and sustain POMC neuronal firing. How communication between tanycytes and hypothalamic neurons occurs in the presence of other metabolites (e.g., amino acids and fatty acids) and how the pathway responds under pathophysiological conditions (e.g., obesity and T2D) remain to be elucidated. FFAs, free fatty acids.