bioRxiv Science⌕ Search

Biology subjects

Yeo, G. S.

Publications and source records attributed to Yeo, G. S..

3 recordsLinked to original sources

Cav3.1 is a leucine sensor in POMC neurons mediating appetite suppression and weight loss

Hypothalamic leucine sensing promotes satiety and weight loss but an understanding of how leucine regulates neuronal activity is lacking. Here we show that Cacna1g, encoding the T-type voltage-gated calcium channel Cav3.1, is enriched in hypothalamic leucine-sensing neurons and mediates leucine sensing. Pharmacological inhibition of Cav3.1 blunts leucine-induced activation of POMC neurons as well as the anorectic response to leucine in vivo. In addition, genetic deletion of Cacna1g in POMC neurons abolishes the appetite- and weight-suppressive effects of high-protein feeding. Mechanistically, we show that leucine binds to the voltage-sensing segment of Cav3.1, thereby reducing its threshold for voltage-dependent activation. Last, pharmacological activation of hypothalamic Cav3.1 promotes weight loss in diet-induced obese mice and potentiates the weight loss response to GLP-1 receptor agonism. These results reveal that Cav3.1 is a neuronal leucine sensor and a relevant weight loss target.

neuroscience↗

Nutritional signals rapidly activate oligodendrocyte differentiation in the adult hypothalamic median eminence

The mediobasal hypothalamus (arcuate nucleus - ARC - and median eminence - ME -) controls energy balance, growth and fertility through its ability to integrate neuronal, nutritional and hormonal signals and coordinate the behavioural, neuroendocrine and metabolic responses required for these functions. While our understanding of the neural circuits downstream from ARC neurons is rapidly progressing, little is known about the function of other cell types. Here we describe an unexpected role for oligodendrocytes (OL) of the ME in monitoring nutritional signals. We show that refeeding following an overnight fast rapidly activates oligodendrocyte differentiation and the production of new OL in the ME specifically. No changes in myelination were measured in this time-frame. However, refeeding changed the expression of OL-derived extracellular matrix proteins decorin and tenascin-R, with consistent changes in the density of local perineuronal nets. Last, we show that OLs use mTORC1 signalling, a pathway required for OL differentiation, to survey energy and protein availability, specifically in the ME. We conclude that new oligodendrocytes formed in the ME in response to nutritional signals control the access of circulating metabolic cues to ARC interoceptive neurons.

neuroscience↗

Comparison of human and murine enteroendocrine cells by transcriptomic and peptidomic profiling

Enteroendocrine cells (EECs) produce hormones that regulate food absorption, insulin secretion and appetite. Both EECs and their peptide products are foci of drug discovery programmes for diabetes and obesity. We compared the human and mouse EEC transcriptome and peptidome to validate mouse as a model of the human enteroendocrine axis. We present the first RNA sequencing analysis of human EECs, and demonstrate strong correlation with mouse, although with outliers including some low abundance G-protein coupled receptors. Liquid chromatography mass spectrometry (LC-MS) identified peptide hormone gradients along the human and mouse gut that should enhance progress in gut physiology and therapeutics.

cell biology↗