Insulin signaling in the central nervous system (CNS) regulates energy balance and peripheral glucose homeostasis. Rictor is a key regulatory/structural subunit of the mTORC2 complex and is required for hydrophobic motif site phosphorylation of Akt at serine 473. To examine the contribution of neuronal Rictor/mTORC2 signaling to CNS regulation of energy and glucose homeostasis, we utilized Cre-LoxP technology to generate mice lacking Rictor in all neurons, or in either POMC or AgRP expressing neurons. Rictor deletion in all neurons led to increased fat mass and adiposity, glucose intolerance and behavioral leptin resistance. Disrupting Rictor in POMC neurons also caused obesity and hyperphagia, fasting hyperglycemia and pronounced glucose intolerance. AgRP neuron specific deletion did not impact energy balance but led to mild glucose intolerance. Collectively, we show that Rictor/mTORC2 signaling, especially in POMC-expressing neurons, is important for central regulation of energy and glucose homeostasis.
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http://dx.doi.org/10.1016/j.molmet.2014.01.014 | DOI Listing |
Am J Physiol Heart Circ Physiol
January 2025
Department of Biochemistry and Molecular Biology, Dalhousie University, Dalhousie Medicine New Brunswick, 355 Campus Ring Road, Saint John, New Brunswick, E2L 4L5, Canada.
Lipid phosphate phosphatase 3 (LPP3) is a membrane-bound enzyme that hydrolyzes lipid phosphates including the bioactive lipid, lysophosphatidic acid (LPA). Elevated circulating LPA production and cellular LPA signaling are implicated in obesity-induced metabolic and cardiac dysfunction. Deletion of LPP3 in the cardiomyocyte increases circulating LPA levels and causes heart failure and mitochondrial dysfunction in mice.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Medical Microbiology and Immunology, University of Nairobi, Nairobi, Kenya.
The lung environment harbours a community of microbes that play a significant role in health and disease, including innate protection against pathogenic microorganisms. Infection with Mycobacterium tuberculosis, psychological stress associated with the tuberculosis (TB) disease, and the metabolites from the rifampicin treatment regimen have been reported to induce hyperglycemia and consequently type 2 diabetes mellitus (T2DM) in individuals not previously diabetic. The high glucose concentration is proposed to alter the composition of the lung microbiota and airway homeostasis, exerting an influence on TB disease and treatment outcomes.
View Article and Find Full Text PDFFood Sci Nutr
January 2025
Laboratory of Biotechnology and Natural Resources Valorization, Faculty of Sciences Ibn Zohr University Agadir Morocco.
Hepatic steatosis/non-alcoholic fatty liver disease is a major public health delinquent caused by the excess deposition of lipid into lipid droplets (LDs) as well as metabolic dysregulation. Hepatic cells buildup with more fat molecules when a person takes high fat diet that is excessive than the body can handle. At present, millions of people in the world are affected by this problem.
View Article and Find Full Text PDFCureus
December 2024
Department of Cardiovascular Medicine, Faculty of Medicine, Tottori University, Yonago, JPN.
The purpose of this study is to examine the pregestational BMI value that results in insulin use in Japanese patients with gestational diabetes mellitus (GDM) and to assess whether the type of GDM treatment affects postpartum glucose tolerance. This retrospective study included 21 GDM patients treated until parturition at our department from 2013 to 2017. We calculated the pregestational BMI related to insulin treatment and the significant elevation in homeostasis model assessment of insulin resistance (HOMA-IR) by receiver operating characteristics curve (ROC) analysis.
View Article and Find Full Text PDFActa Physiol (Oxf)
February 2025
Laboratory of Biological Rhythms, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic.
Aim: Exposure to light at night and meal time misaligned with the light/dark (LD) cycle-typical features of daily life in modern 24/7 society-are associated with negative effects on health. To understand the mechanism, we developed a novel protocol of complex chronodisruption (CD) in which we exposed female rats to four weekly cycles consisting of 5-day intervals of constant light and 2-day intervals of food access restricted to the light phase of the 12:12 LD cycle.
Methods: We examined the effects of CD on behavior, estrous cycle, sleep patterns, glucose homeostasis and profiles of clock- and metabolism-related gene expression (using RT qPCR) and liver metabolome and lipidome (using untargeted metabolomic and lipidomic profiling).
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