Objective: Adiponectin receptors (AdipoRs) are located on neurons of the hypothalamus involved in metabolic regulation - including arcuate proopiomelanocortin (Pomc) and Neuropeptide Y/Agouti-related peptide (NPY/AgRP) neurons. AdipoRs play a critical role in regulating glucose and fatty acid metabolism by initiating several signaling cascades overlapping with Leptin receptors (LepRs). However, the mechanism by which adiponectin regulates cellular activity in the brain remains undefined.
Methods: In order to resolve this issue, we utilized neuron-specific transgenic mouse models to identify Pomc and NPY/AgRP neurons which express LepRs for patch-clamp electrophysiology experiments.
Results: We found that leptin and adiponectin synergistically activated melanocortin neurons in the arcuate nucleus. Conversely, NPY/AgRP neurons were inhibited in response to adiponectin. The adiponectin-induced depolarization of arcuate Pomc neurons occurred via activation of Phosphoinositide-3-kinase (PI3K) signaling, independent of 5' AMP-activated protein kinase (AMPK) activity. Adiponectin also activated melanocortin neurons at various physiological glucose levels.
Conclusions: Our results demonstrate a requirement for PI3K signaling in the acute adiponectin-induced effects on the cellular activity of arcuate melanocortin neurons. Moreover, these data provide evidence for PI3K as a substrate for both leptin and adiponectin to regulate energy balance and glucose metabolism via melanocortin activity.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5034606 | PMC |
http://dx.doi.org/10.1016/j.molmet.2016.08.007 | DOI Listing |
Gene
February 2025
Departments of Physiology, University of Toronto, Ontario, Canada; Departments of Medicine, University of Toronto, Ontario, Canada. Electronic address:
Obesity is a complex disease marked by increased adiposity and impaired metabolic function. While diet and lifestyle are primary causes, endocrine-disrupting chemicals (EDCs), such as bisphenol A (BPA), significantly contribute to obesity. BPA, found in plastic consumer products, accumulates in the hypothalamus and dysregulates energy homeostasis by disrupting the neuropeptide Y (NPY)/agouti-related peptide (AgRP) and pro-opiomelanocortin (POMC) neurons.
View Article and Find Full Text PDFMol Cells
November 2024
Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea. Electronic address:
It is well known that the G protein-gated inwardly rectifying K (GIRK) channels are critical to maintain excitability of central neurons. GIRK channels consist of 4 subunits and GIRK1/GIRK2 heterotetramers are considered to be the neuronal prototype. We previously reported the metabolic significance of GIRK2 subunits expressed by the neuropeptide Y (NPY)/agouti-related peptide (AgRP) neurons of the arcuate nucleus of the hypothalamus (ARH).
View Article and Find Full Text PDFJ Agric Food Chem
October 2024
College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, China.
The diet in early life is essential for the growth and intestinal health later in life. However, beneficial effects of a diet enriched in branched short-chain fatty acids (BSCFAs) for infants are ambiguous. This study aimed to develop a novel fermented protein food, enriched with BSCFAs and assess the effects of dry and wet ferment products on young pig development, nutrient absorption, intestinal barrier function, and gut microbiota and metabolites.
View Article and Find Full Text PDFNeuropeptides
December 2024
Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA. Electronic address:
The molecular mechanisms underlying neuronal leptin and insulin resistance in obesity and diabetes are not fully understood. In this study, we show that induction of the unfolded protein response transcription factor, spliced X-box binding protein 1 (Xbp1s), in Agouti-Related Peptide (AgRP) neurons alone, is sufficient to not only protect against but also significantly reverse diet-induced obesity (DIO) as well as improve leptin and insulin sensitivity, despite activation of endoplasmic reticulum stress. We also demonstrate that constitutive expression of Xbp1s in AgRP neurons contributes to improved insulin sensitivity and glucose tolerance.
View Article and Find Full Text PDFNeuropeptides
October 2024
School of Psychology, University of New South Wales, Australia.
Neuropeptide Y (NPY) plays a crucial role in controlling energy homeostasis and feeding behaviour. The role of NPY neurons located in the arcuate nucleus of the hypothalamus (Arc) in responding to homeostatic signals has been the focus of much investigation, but most studies have used AgRP promoter-driven models, which do not fully encompass Arc NPY neurons. To directly investigate NPY-expressing versus AgRP-expressing Arc neurons function, we utilised chemogenetic techniques in NPY-Cre and AgRP-Cre animals to activate Arc NPY or AgRP neurons in the presence of food and food-related stimuli.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!