GKRP-dependent modulation of feeding behavior by tanycyte-released monocarboxylates

Magdiel Salgado, Roberto Elizondo-Vega, Pablo S. Villar, Macarena Konar, Scarlet Gallegos, Estefanía Tarifeño-Saldivia, Patricia Luz-Crawford, Luis G. Aguayo, Ricardo C. Araneda, Elena Uribe, María Ángeles García-Robles*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Objectives: Glucokinase Regulatory Protein (GKRP) is the only known endogenous modulator of glucokinase (GK) localization and activity to date, and both proteins are localized in tanycytes, radial glia-like cells involved in metabolic and endocrine functions in the hypothalamus. However, the role of tanycytic GKRP and its impact on the regulation of feeding behavior has not been investigated. Here, we hypothesize that GKRP regulates feeding behavior by modulating tanycyte-neuron metabolic communication in the arcuate nucleus. Methods: We used primary cultures of tanycytes to evaluate the production of lactate and β-hydroxybutyrate (βHB). Similarly, we examined the electrophysiological responses to these metabolites in pro-opiomelanocortin (POMC) neurons in hypothalamic slices. To evaluate the role of GKRP in feeding behavior, we generated tanycyte-selective GKRP-overexpressing and GKRP-knock down mice (GKRPt-OE and GKRPt-KD respectively) using adenovirus-mediated transduction. Results: We demonstrated that lactate release induced by glucose uptake is favored in GKRP-KD tanycytes. Conversely, tanycytes overexpressing GKRP showed an increase in βHB efflux induced by low glucose concentration. In line with these findings, the excitability of POMC neurons was enhanced by lactate and decreased in the presence of βHB. In GKRPt-OE rats, we found an increase in post-fasting food avidity, whereas GKRPt-KD caused a significant decrease in feeding and body weight, which is reverted when MCT1 is silenced. Conclusion: Our study highlights the role of tanycytic GKRP in metabolic regulation and positions this regulator of GK as a therapeutic target for boosting satiety in patients with obesity problems.

Original languageEnglish
Pages (from-to)1518-1536
Number of pages19
JournalTheranostics
Volume12
Issue number4
DOIs
StatePublished - 2022

Bibliographical note

Funding Information:
This work was supported by grants from the Agencia Nacional de Investigación y Desarrollo-ANID: "Fondecyt Regular" Nº1180871(to M.G-R); Beca Doctorado Nacional 2014 Nº 21141042 (to M.S.); “Fondecyt iniciación” Nº 11190690 (to R.E-V). The authors would like to especially thank Vet. Med. Joaquin Rojas (Crea-Vida Biobio, Animal Care Facility) for technical expertise and assistance in the in vivo experiments and Dra. Marjet Heitzer for her helpful discussion and suggestions on the manuscript.

Publisher Copyright:
© 2022 Ivyspring International Publisher. All rights reserved.

Keywords

  • Feeding behavior
  • GKRP
  • Lactate
  • Obesity
  • Tanycyte
  • β-hydroxybutyrate

Fingerprint

Dive into the research topics of 'GKRP-dependent modulation of feeding behavior by tanycyte-released monocarboxylates'. Together they form a unique fingerprint.

Cite this