scholarly journals The multifunctional protein E4F1 links P53 to lipid metabolism in adipocytes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Matthieu Lacroix ◽  
Laetitia K. Linares ◽  
Natalia Rueda-Rincon ◽  
Katarzyna Bloch ◽  
Michela Di Michele ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Lipid Metabolism ◽  
Direct Interaction ◽  
Monounsaturated Fatty Acids ◽  
Transcriptional Program ◽  
Improve Insulin Sensitivity ◽  
Multifunctional Protein ◽  
Metabolic Functions ◽  
Deficient Mice

AbstractGrowing evidence supports the importance of the p53 tumor suppressor in metabolism but the mechanisms underlying p53-mediated control of metabolism remain poorly understood. Here, we identify the multifunctional E4F1 protein as a key regulator of p53 metabolic functions in adipocytes. While E4F1 expression is upregulated during obesity, E4f1 inactivation in mouse adipose tissue results in a lean phenotype associated with insulin resistance and protection against induced obesity. Adipocytes lacking E4F1 activate a p53-dependent transcriptional program involved in lipid metabolism. The direct interaction between E4F1 and p53 and their co-recruitment to the Steaoryl-CoA Desaturase-1 locus play an important role to regulate monounsaturated fatty acids synthesis in adipocytes. Consistent with the role of this E4F1-p53-Steaoryl-CoA Desaturase-1 axis in adipocytes, p53 inactivation or diet complementation with oleate partly restore adiposity and improve insulin sensitivity in E4F1-deficient mice. Altogether, our findings identify a crosstalk between E4F1 and p53 in the control of lipid metabolism in adipocytes that is relevant to obesity and insulin resistance.

scholarly journals Gormony zhirovoy tkani i funktsional'nayaaktivnost' shchitovidnoy zhelezy

2010 ◽  
Vol 7 (4) ◽  
pp. 8-11 ◽  
Author(s):  
N A Petunina ◽  
N E Al'tshuler ◽  
N G Rakova ◽  
L V Trukhina
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Lipid Metabolism ◽  
Subclinical Hypothyroidism ◽  
Thyroid Dysfunction ◽  
The Impact ◽  
The Relationship ◽  
Tissue Hormones

The review presents a recent data from the literature on the physiologic and pathophysiologic role of adipose tissue hormones (adiponectin, resistin, leptin). The article details the role of adipocytokines in atherogenesis. It also presents the results of studies depicting the relationship between subclinical hypothyroidism, lipid metabolism and insulin resistance as well as the impact of thyroid dysfunction upon the secretion of adipocytokines.

scholarly journals Osteopontin Expression in Human and Murine Obesity: Extensive Local Up-Regulation in Adipose Tissue but Minimal Systemic Alterations

Endocrinology ◽  
2007 ◽  
Vol 149 (3) ◽  
pp. 1350-1357 ◽  
Author(s):  
Florian W. Kiefer ◽  
Maximilian Zeyda ◽  
Jelena Todoric ◽  
Joakim Huber ◽  
René Geyeregger ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Plasma Concentrations ◽  
Morbidly Obese ◽  
Low Grade ◽  
Obese Patients ◽  
Multifunctional Protein ◽  
Inflammatory Processes ◽  
Low Grade Inflammation

Obesity is associated with a chronic low-grade inflammation characterized by macrophage infiltration of adipose tissue (AT) that may underlie the development of insulin resistance and type 2 diabetes. Osteopontin (OPN) is a multifunctional protein involved in various inflammatory processes, cell migration, and tissue remodeling. Because these processes occur in the AT of obese patients, we studied in detail the regulation of OPN expression in human and murine obesity. The study included 20 morbidly obese patients and 20 age- and sex-matched control subjects, as well as two models (diet-induced and genetic) of murine obesity. In high-fat diet-induced and genetically obese mice, OPN expression was drastically up-regulated in AT (40 and 80-fold, respectively) but remained largely unaltered in liver (<2-fold). Moreover, OPN plasma concentrations remained unchanged in both murine models of obesity, suggesting a particular local but not systemic importance for OPN. OPN expression was strongly elevated also in the AT of obese patients compared with lean subjects in both omental and sc AT. In addition, we detected three OPN isoforms to be expressed in human AT and, strikingly, an obesity induced alteration of the OPN isoform expression pattern. Analysis of AT cellular fractions revealed that OPN is exceptionally highly expressed in AT macrophages in humans and mice. Moreover, OPN expression in AT macrophages was strongly up-regulated by obesity. In conclusion, our data point toward a specific local role of OPN in obese AT. Therefore, OPN could be a critical regulator in obesity induced AT inflammation and insulin resistance.

scholarly journals Loss of Mrap2 is associated with Sim1 deficiency and increased circulating cholesterol

2016 ◽  
Vol 230 (1) ◽  
pp. 13-26 ◽  
Author(s):  
T V Novoselova ◽  
R Larder ◽  
D Rimmington ◽  
C Lelliott ◽  
E H Wynn ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Metabolic Regulation ◽  
Energy Homeostasis ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Melanocortin Receptor ◽  
Accessory Protein ◽  
Loss Of Function ◽  
Deficient Mice

Melanocortin receptor accessory protein 2 (MRAP2) is a transmembrane accessory protein predominantly expressed in the brain. Both global and brain-specific deletion of Mrap2 in mice results in severe obesity. Loss-of-function MRAP2 mutations have also been associated with obesity in humans. Although MRAP2 has been shown to interact with MC4R, a G protein-coupled receptor with an established role in energy homeostasis, appetite regulation and lipid metabolism, the mechanisms through which loss of MRAP2 causes obesity remains uncertain. In this study, we used two independently derived lines of Mrap2 deficient mice (Mrap2tm1a/tm1a) to further study the role of Mrap2 in the regulation of energy balance and peripheral lipid metabolism. Mrap2tm1a/tm1a mice have a significant increase in body weight, with increased fat and lean mass, but without detectable changes in food intake or energy expenditure. Transcriptomic analysis showed significantly decreased expression of Sim1, Trh, Oxt and Crh within the hypothalamic paraventricular nucleus of Mrap2tm1a/tm1a mice. Circulating levels of both high-density lipoprotein and low-density lipoprotein were significantly increased in Mrap2 deficient mice. Taken together, these data corroborate the role of MRAP2 in metabolic regulation and indicate that, at least in part, this may be due to defective central melanocortin signalling.

Role of stearoyl-CoA desaturase-1 in skeletal muscle function and metabolism

2013 ◽  
Vol 305 (7) ◽  
pp. E767-E775 ◽  
Author(s):  
Alexis D. Stamatikos ◽  
Chad M. Paton
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acids ◽  
Lipid Metabolism ◽  
Saturated Fatty Acids ◽  
Monounsaturated Fatty Acids ◽  
Skeletal Muscle Function ◽  
Skeletal Muscle Lipid ◽  
Stearoyl Coa Desaturase ◽  
Scd1 Expression

Stearoyl-CoA desaturase-1 (SCD1) converts saturated fatty acids (SFA) into monounsaturated fatty acids and is necessary for proper liver, adipose tissue, and skeletal muscle lipid metabolism. While there is a wealth of information regarding SCD1 expression in the liver, research on its effect in skeletal muscle is scarce. Furthermore, the majority of information about its role is derived from global knockout mice, which are known to be hypermetabolic and fail to accumulate SCD1's substrate, SFA. We now know that SCD1 expression is important in regulating lipid bilayer fluidity, increasing triglyceride formation, and enabling lipogenesis and may protect against SFA-induced lipotoxicity. Exercise has been shown to increase SCD1 expression, which may contribute to an increase in intramyocellular triglyceride at the expense of free fatty acids and diacylglycerol. This review is intended to define the role of SCD1 in skeletal muscle and discuss the potential benefits of its activity in the context of lipid metabolism, insulin sensitivity, exercise training, and obesity.

scholarly journals SCD1, autophagy and cancer: implications for therapy

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Francesca Ascenzi ◽  
Claudia De Vitis ◽  
Marcello Maugeri-Saccà ◽  
Christian Napoli ◽  
Gennaro Ciliberto ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Lipid Metabolism ◽  
Monounsaturated Fatty Acids ◽  
Cellular Functions ◽  
Cancer Heterogeneity ◽  
Intracellular Degradation ◽  
Mutual Regulation ◽  
Key Enzyme ◽  
Proliferation And Metastasis

Abstract Background Autophagy is an intracellular degradation system that removes unnecessary or dysfunctional components and recycles them for other cellular functions. Over the years, a mutual regulation between lipid metabolism and autophagy has been uncovered. Methods This is a narrative review discussing the connection between SCD1 and the autophagic process, along with the modality through which this crosstalk can be exploited for therapeutic purposes. Results Fatty acids, depending on the species, can have either activating or inhibitory roles on autophagy. In turn, autophagy regulates the mobilization of fat from cellular deposits, such as lipid droplets, and removes unnecessary lipids to prevent cellular lipotoxicity. This review describes the regulation of autophagy by lipid metabolism in cancer cells, focusing on the role of stearoyl-CoA desaturase 1 (SCD1), the key enzyme involved in the synthesis of monounsaturated fatty acids. SCD1 plays an important role in cancer, promoting cell proliferation and metastasis. The role of autophagy in cancer is more complex since it can act either by protecting against the onset of cancer or by promoting tumor growth. Mounting evidence indicates that autophagy and lipid metabolism are tightly interconnected. Conclusion Here, we discuss controversial findings of SCD1 as an autophagy inducer or inhibitor in cancer, highlighting how these activities may result in cancer promotion or inhibition depending upon the degree of cancer heterogeneity and plasticity.

The Role of Adiponectin in Maintaining Metabolic Homeostasis

2020 ◽  
Vol 16 (2) ◽  
pp. 95-103 ◽  
Author(s):  
Suleyman Cem Adiyaman ◽  
Muhammet Ozer ◽  
Basak Ozgen Saydam ◽  
Baris Akinci
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Lipid Metabolism ◽  
Cardiovascular Health ◽  
Metabolic Diseases ◽  
Metabolic Homeostasis ◽  
Glucose And Lipid Metabolism ◽  
Treatment Of Diabetes ◽  
Novel Targets

Background: Adiponectin is an adipocyte-derived cytokine closely associated with obesity, altered body adipose tissue distribution, insulin resistance, and cardiovascular diseases. Introduction: Evidence from animal and human studies demonstrate that adiponectin plays an important role in the regulation of glucose and lipid metabolism. Adiponectin increases insulin sensitivity and improves systemic lipid metabolism. Although research efforts on adiponectin mostly aim towards its endocrine functions, this adipocyte-derived molecule also has profound autocrine and paracrine functions. Conclusion: In this review, our aim is to discuss the role of adiponectin in maintaining metabolic homeostasis and its association with cardiovascular health. The proper identification of these roles is of great importance, which has the potential to identify a wealth of novel targets for the treatment of diabetes and related cardio-metabolic diseases.

scholarly journals Obesity-linked PPARγ S273 phosphorylation promotes insulin resistance through Growth Differentiation Factor 3

2020 ◽  
Author(s):  
Jessica A. Hall ◽  
Deepti Ramachandran ◽  
Hyun C. Roh ◽  
Joanna R. DiSpirito ◽  
Thiago Belchior ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Side Effects ◽  
Ectopic Expression ◽  
Bmp Signaling ◽  
Whole Body ◽  
Improve Insulin Sensitivity ◽  
Induce Insulin Resistance ◽  
Systemic Insulin Resistance

AbstractOvernutrition and obesity promote adipose tissue dysfunction, often leading to systemic insulin resistance. The thiazolidinediones (TZDs) are a potent class of insulin-sensitizing drugs and ligands of PPARγ that improve insulin sensitivity, but their use is limited due to significant side effects. Recently, we demonstrated a mechanism by which TZDs improve insulin sensitivity distinct from receptor agonism and adipogenesis: reversal of obesity-linked phosphorylation of PPARγ at Serine 273. However, the role of this modification has not been tested genetically. Here we demonstrate that mice encoding an allele of PPARγ which cannot be phosphorylated at S273 are protected from insulin resistance, without exhibiting differences in body weight or TZD-associated side effects. Indeed, hyperinsulinemic-euglycemic clamp experiments confirm improved insulin sensitivity, as evidenced by increased whole-body glucose uptake. RNA-seq experiments reveal PPARγ S273 phosphorylation specifically enhances transcription of Gdf3, a BMP family member. Ectopic expression of Gdf3 is sufficient to induce insulin resistance in lean, healthy mice. We find that Gdf3 can impact metabolism by inhibition of BMP signaling. Together, these results highlight the diabetogenic role of PPARγ S273 phosphorylation and focuses attention on a putative target, Gdf3.

scholarly journals Hepatic insulin resistance and increased hepatic glucose production in mice lacking Fgf21

2015 ◽  
Vol 226 (3) ◽  
pp. 207-217 ◽  
Author(s):  
João Paulo G Camporez ◽  
Mohamed Asrih ◽  
Dongyan Zhang ◽  
Mario Kahn ◽  
Varman T Samuel ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Lipid Metabolism ◽  
Hepatic Glucose Production ◽  
Glucose Production ◽  
Hepatic Insulin Resistance ◽  
Whole Body ◽  
Fibroblast Growth Factor 21 ◽  
Glucose And Lipid Metabolism ◽  
Hepatic Glucose

Fibroblast growth factor 21 (FGF21) is an important regulator of hepatic glucose and lipid metabolism and represents a potential pharmacological agent for the treatment of type 2 diabetes and obesity. Mice fed a ketogenic diet (KD) develop hepatic insulin resistance in association with high levels of FGF21, suggesting a state of FGF21 resistance. To address the role of FGF21 in hepatic insulin resistance, we assessed insulin action in FGF21 whole-body knock-out (FGF21 KO) male mice and their littermate WT controls fed a KD. Here, we report that FGF21 KO mice have hepatic insulin resistance and increased hepatic glucose production associated with an increase in plasma glucagon levels. FGF21 KO mice are also hypometabolic and display increased fat mass compared with their WT littermates. Taken together, these findings support a major role of FGF21 in regulating energy expenditure and hepatic glucose and lipid metabolism, and its potential role as a candidate in the treatment of diseases associated with insulin resistance.

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