Metabolic health depends on the brain’s ability to control food intake and nutrient use versus storage, processes that require peripheral signals such as the adipocyte-derived hormone, leptin, to cross brain barriers and mobilize regulatory circuits. We have previously shown that hypothalamic tanycytes shuttle leptin into the brain to reach target neurons. Here, using multiple complementary models, we show that tanycytes express functional leptin receptor (LepR), respond to leptin by triggering Ca2+ waves and target protein phosphorylation, and that their transcytotic transport of leptin requires the activation of a LepR–EGFR complex by leptin and EGF sequentially. Selective deletion of LepR in tanycytes blocks leptin entry into the brain, inducing not only increased food intake and lipogenesis but also glucose intolerance through attenuated insulin secretion by pancreatic β-cells, possibly via altered sympathetic nervous tone. Tanycytic LepRb–EGFR-mediated transport of leptin could thus be crucial to the pathophysiology of diabetes in addition to obesity, with therapeutic implications.

Leptin brain entry via a tanycytic LepR–EGFR shuttle controls lipid metabolism and pancreas function

Mazzone M.;
2021-01-01

Abstract

Metabolic health depends on the brain’s ability to control food intake and nutrient use versus storage, processes that require peripheral signals such as the adipocyte-derived hormone, leptin, to cross brain barriers and mobilize regulatory circuits. We have previously shown that hypothalamic tanycytes shuttle leptin into the brain to reach target neurons. Here, using multiple complementary models, we show that tanycytes express functional leptin receptor (LepR), respond to leptin by triggering Ca2+ waves and target protein phosphorylation, and that their transcytotic transport of leptin requires the activation of a LepR–EGFR complex by leptin and EGF sequentially. Selective deletion of LepR in tanycytes blocks leptin entry into the brain, inducing not only increased food intake and lipogenesis but also glucose intolerance through attenuated insulin secretion by pancreatic β-cells, possibly via altered sympathetic nervous tone. Tanycytic LepRb–EGFR-mediated transport of leptin could thus be crucial to the pathophysiology of diabetes in addition to obesity, with therapeutic implications.
2021
Brain
Diabetes Mellitus
Energy Metabolism
Ependymoglial Cells
ErbB Receptors
Insulin-Secreting Cells
Leptin
Pancreas
Phosphorylation
Receptors
Leptin
Lipid Metabolism
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11699/83049
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 60
  • ???jsp.display-item.citation.isi??? 57
social impact