Dataset Information

Chronic AMP-kinase activation with AICAR reduces adiposity by remodeling adipocyte metabolism and increasing leptin sensitivity.

ABSTRACT: This study investigated the effect of chronic AMP-kinase (AMPK) activation with 5-aminoimidazole-4-carboxamide-1-?-D-ribofuranoside (AICAR) on white adipose tissue (WAT) metabolism and the implications for visceral (VC) and subcutaneous (SC) adiposity, whole body-energy homeostasis, and hypothalamic leptin sensitivity. Male Wistar rats received daily single intraperitoneal injections of either saline or AICAR (0.7g/kg body weight) for 4 and 8 weeks and were pair-fed throughout the study. AICAR-treated rats had reduced adiposity with increased mitochondrial density in VC and SC fat pads, which was accompanied by reduced circulating leptin and time-dependent and depot-specific regulation of AMPK phosphorylation and FA oxidation. Interestingly, the anorectic effect to exogenous leptin was more pronounced in AICAR-treated animals than controls. This corresponded to reductions in hypothalamic AMPK phosphorylation and suppressor of cytokine signaling 3 content, whereas signal transducer and activator of transcription 3 phosphorylation was either unchanged or increased at 4 and 8 weeks in AICAR-treated rats. Ambulatory activity and whole-body energy expenditure (EE) were also increased with AICAR treatment. Altogether, chronic AICAR-induced AMPK activation increased WAT oxidative machinery, whole-body EE, and hypothalamic leptin sensitivity. This led to significant reductions in VC and SC adiposity without inducing energy-sparing mechanisms that oppose long-term fat loss.

SUBMITTER: Gaidhu MP

PROVIDER: S-EPMC3151690 | biostudies-literature | 2011 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Chronic AMP-kinase activation with AICAR reduces adiposity by remodeling adipocyte metabolism and increasing leptin sensitivity.

Gaidhu Mandeep P MP Frontini Andrea A Hung Steven S Pistor Kathryn K Cinti Saverio S Ceddia Rolando B RB

Journal of lipid research 20110707 9

This study investigated the effect of chronic AMP-kinase (AMPK) activation with 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) on white adipose tissue (WAT) metabolism and the implications for visceral (VC) and subcutaneous (SC) adiposity, whole body-energy homeostasis, and hypothalamic leptin sensitivity. Male Wistar rats received daily single intraperitoneal injections of either saline or AICAR (0.7g/kg body weight) for 4 and 8 weeks and were pair-fed throughout the study. AICAR-t ...[more]

PMID: 21737753

Similar Datasets

Project description:Introduction: Obesity and overweight affect more than one third of the world population, and are significant risk factors for type II diabetes, cardiovascular disease and cancer. Common obesity is usually accompanied by hyperleptinemia and leptin resistance. Purpose: Here, we investigate the molecular pathways underlying the effects of HDAC6 inhibition in reversing diet-induced obesity and interrogate potential pathways that link HDAC6 with leptin receptor signaling by conducting whole transcriptome analysis in white adipose tissues of the diet-induced obese mice that were treated with tubastatin A (an HDAC6-specific inhibitor) and in fat-specific HDAC6 knockout mice. Methods: Male 4-5 week-old C57B/6J wild type mice were fed with high fat diet for 16-20 weeks to generate diet-induced obese (DIO) mice. Around 28 weeks of age, mice were treated with daily ip injections of either tubastatin A-HCl (TubA, 25 mg/kg) or vehicle for four days. We probed the whole transcriptome in epididymal white adipose tissue (eWAT), and inguinal white adipose tissue (iWAT) following vehicle or TubA administration (eWAT.Veh, eWAT.TubA, iWAT.Veh, iWAT.TubA groups). In a separate cohort, DIO HDAC6 global knockout mice were treated with vehicle (Veh group) or TubA (TubA group). eWAT was excised for RNA extraction. In the third cohort, adipose tissue specific HDAC6 knockout mice were generated crossing adiponectin-Cre mice with HDAC6-floxed mice. These fat specific HDAC6 KO mice (AdKO) and their adiponectin-Cre controls (AdCre) were treated with vehicle for five weeks. eWAT was excised for RNA extraction.Total RNA samples from each tissue were extracted using Trizol. RNA Sequencing for the wild-type iWAT and eWAT samples from vehicle or TubA-treated mice was performed by the University of Michigan Sequencing Core, using the Illumina Hi-Seq 4000 platform. RNA sequencing for the other samples were conducted by Novogene, NovaSeq 6000 PE150, HiSeq SE50 platform. The following bioinformatics analysis have been conducted by Novogene: 1. Data Quality Control: filtering reads containing adapter or with low quality. 2. Statistics Analysis of Data Production and Quality. 3. Mapping Reads to Reference Genome. 4. Gene Expression Quantification. 5. Correlation analysis (For biological replicates only). 6. Differential Expression Analysis (two or more groups of samples). 7. GO Enrichment Analysis of Differentially Expressed Genes (DEGs) (two or more groups of samples). 8. KEGG Pathway Enrichment Analysis of Differentially Expressed Genes (DEGs) (two or more groups of samples). 9. GSEA Enrichment Analysis of Expressed Genes (two or more groups of samples). 10. Protein Protein Interaction Analysis. 11. Reactome Pathway Enrichment Analysis of Differentially Expressed Genes (DEGs) (two or more groups of samples and only for mouse samples). 12. Oncogene Functional Annotation analysis of Differentially Expressed Genes (DEGs) (two or more groups of samples and only for mouse sample). Results: Inhibitors of the cytosolic enzyme histone deacetylase 6 (HDAC6) act as potent anti-obesity agents, and leptin sensitizers. HDAC6 inhibitor TubA suppresses food intake and reduce obesity, in an HDAC6-dependent manner, resulting in up to fifty percent decrease in fat mass in DIO mice accompanied by significantly reduced hepatic steatosis and improved systemic glucose homeostasis. Conclusions: Mechanistically, peripheral -but not central- inhibition of HDAC6 confers central leptin sensitivity, and the anti-obesity effect of TubA is significantly attenuated in animals defective in the central leptin-melanocortin circuitry, including the db/db and MCR4 KO mice.

Project description:When the yeast Saccharomyces cerevisiae is subjected to increasing glycolytic fluxes under aerobic conditions, there is a threshold value of the glucose uptake rate at which the metabolism shifts from being purely respiratory to mixed respiratory and fermentative. This shift is characterized by ethanol production, a phenomenon known as the Crabtree effect due to its analogy with lactate overflow in cancer cells. It is well known that at high glycolytic fluxes there is glucose repression of respiratory pathways resulting in a decrease in the respiratory capacity. Despite many years of detailed studies on this subject, it is not known whether the onset of the Crabtree effect (or overflow metabolism) is due to a limited respiratory capacity or caused by glucose-mediated repression of respiration. We addressed this issue by increasing respiration in S. cerevisiae by introducing a heterologous alternative oxidase, and observed reduced aerobic ethanol formation. In contrast, increasing non-respiratory NADH oxidation by overexpression of a water-forming NADH oxidase reduced aerobic glycerol formation. The metabolic response to elevated alternative oxidase occurred predominantly in the mitochondria, while NADH oxidase affected genes that catalyze cytosolic reactions. Moreover, NADH oxidase restored the deficiency of cytosolic NADH dehydrogenases in S. cerevisiae. These results indicate that NADH oxidase localizes in the cytosol, while alternative oxidase is directed to the mitochondria. The onset of aerobic ethanol formation is demonstrated to be a consequence of an imbalance in mitochondrial redox balancing. In addition to answering fundamental physiological questions, our findings are relevant for all biomass derived applications of S. cerevisiae. Experiment Overall Design: Heterologous gene expression in chemostats using Affymetrix Yeast Genome 2.0 arrays. Total RNA extraction and sample preparation, hybridization was done according to the manufacturer's protocol.

Project description:Gene-targeted deletion of the voltage-gated potassium channel, Kv1.3, results in 'super-smeller' mice that have altered firing patterns of mitral cells in the olfactory bulb, modified axonal targeting to glomerular synaptic units, and behaviorally have an increased ability to detect and discriminate odors. Moreover, the Kv1.3-null mice weighed less than their wild-type counterparts, have modified ingestive behaviors, and are resistant to fat deposition following a moderately high-fat dietary regime. In this study, we investigate whether or not gene-targeted deletion of Kv1.3 (Shaker family member) can abrogate weight gain in a genetic model of obesity, the melanocortin-4 receptor-null mouse (MC4R-null).Mice with double gene-targeted deletions of Kv1.3 and MC4R were generated by interbreeding Kv1.3 (Kv)- and MC4R-null mouse lines to homozygosity. Developmental weights, nose to anus length, fat pad weight, fasting serum chemistry, oxygen consumption, carbon dioxide respiration, locomotor activity and caloric intake were monitored in control, Kv-null, MC4R-null and Kv/MC4R-null mice. Physiological and metabolic profiles were acquired at postnatal day 60 (P60) in order to explore changes linked to body weight at the reported onset of obesity in the MC4R-null model.Gene-targeted deletion of Kv1.3 in MC4R-null mice reduces body weight by decreasing fat deposition and subsequent fasting leptin levels, without changing the overall growth, fasting blood glucose or serum insulin. Gene-targeted deletion of Kv1.3 in MC4R-null mice significantly extended lifespan and increased reproductive success. Basal or light-phase mass-specific metabolic rate and locomotor activity were not affected by genetic deletion of Kv1.3 in MC4R-null mice but dark-phase locomotor activity and mass-specific metabolism were significantly increased resulting in increased total energy expenditure.Gene-targeted deletion of Kv1.3 can reduce adiposity and total body weight in a genetic model of obesity by increasing both locomotor activity and mass-specific metabolism.

Dataset Information

Chronic AMP-kinase activation with AICAR reduces adiposity by remodeling adipocyte metabolism and increasing leptin sensitivity.

Publications

Chronic AMP-kinase activation with AICAR reduces adiposity by remodeling adipocyte metabolism and increasing leptin sensitivity.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets