p53 is a well-known tumor suppressor that has emerged as an important player in energy balance. However, its metabolic role in the hypothalamus remains unknown. Herein, we show that mice lacking p53 in agouti-related peptide (AgRP), but not proopiomelanocortin (POMC) or steroidogenic factor-1 (SF1) neurons, are more prone to develop diet-induced obesity and show reduced brown adipose tissue (BAT) thermogenic activity. AgRP-specific ablation of p53 resulted in increased hypothalamic c-Jun N-terminal kinase (JNK) activity before the mice developed obesity, and central inhibition of JNK reversed the obese phenotype of these mice. The overexpression of p53 in the ARC or specifically in AgRP neurons of obese mice decreased body weight and stimulated BAT thermogenesis, resulting in body weight loss. Finally, p53 in AgRP neurons regulates the ghrelin-induced food intake and body weight. Overall, our findings provide evidence that p53 in AgRP neurons is required for normal adaptations against diet-induced obesity.
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http://dx.doi.org/10.1038/s41467-018-05711-6 | DOI Listing |
Mol Metab
January 2025
Center for Hypothalamic Research and Department of Internal medicine, UT Southwestern Medical Center, Dallas, TX. Electronic address:
Agouti-related peptide (AgRP) is a well-established potent orexigenic peptide primarily expressed in hypothalamic neurons. Nevertheless, the expression and functional significance of extrahypothalamic AgRP remain poorly understood. In this study, utilizing histological and molecular biology techniques, we have identified a significant expression of Agrp mRNA and AgRP peptide production in glomus type I cells within the mouse carotid body (CB).
View Article and Find Full Text PDFCell Metab
December 2024
Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Program in Neuroscience, Harvard Medical School, Boston, MA, USA. Electronic address:
When food is freely available, eating occurs without energy deficit. While agouti-related peptide (AgRP) neurons are likely involved, their activation is thought to require negative energy balance. To investigate this, we implemented long-term, continuous in vivo fiber-photometry recordings in mice.
View Article and Find Full Text PDFCaloric depletion leads to behavioral changes that help an animal find food and restore its homeostatic balance. Hunger increases exploration and risk-taking behavior, allowing an animal to forage for food despite risks; however, the neural circuitry underlying this change is unknown. Here, we characterize how hunger restructures an animal's spontaneous behavior as well as its directed exploration of a novel object.
View Article and Find Full Text PDFBMC Biol
December 2024
Key Laboratory of Environmental Stress and Chronic Disease Control & Prevention Ministry of Education, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang, Liaoning, 110122, People's Republic of China.
Background: Epidemiologic researches show that short sleep duration may affect feeding behaviors resulting in higher energy intake and increased risk of obesity, but the further mechanisms that can interpret the causality remain unclear. The circadian rhythm is fine-tuned by the suprachiasmatic nucleus (SCN) as the master clock, which is essential for driving rhythms in food intake and energy metabolism through neuronal projections to the arcuate nucleus (ARC) and paraventricular nucleus (PVN).
Results: We showed that chronic SD-induced aberrant expressions of AgRP/NPY and POMC attributed to compromised JAK/STAT3 signals and reduced energy expenditure in the mice, which can be rescued with AAV-genetic overexpression of BMAL1 into SCN.
Neurosci Bull
December 2024
Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Key Laboratory of Immune Response and Immunotherapy, CAS Key Laboratory of Brain Function and Disease, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China.
In the face of constantly changing environments, the central nervous system (CNS) rapidly and accurately calculates the body's needs, regulates feeding behavior, and maintains energy homeostasis. The arcuate nucleus of the hypothalamus (ARC) plays a key role in this process, serving as a critical brain region for detecting nutrition-related hormones and regulating appetite and energy homeostasis. Agouti-related protein (AgRP)/neuropeptide Y (NPY) neurons in the ARC are core elements that interact with other brain regions through a complex appetite-regulating network to comprehensively control energy homeostasis.
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