Science.gov

Sample records for adipose tissue function

  1. Secretory function of adipose tissue.

    PubMed

    Kuryszko, J; Sławuta, P; Sapikowski, G

    2016-01-01

    There are two kinds of adipose tissue in mammals: white adipose tissue - WAT and brown adipose tissue - BAT. The main function of WAT is accumulation of triacylglycerols whereas the function of BAT is heat generation. At present, WAT is also considered to be an endocrine gland that produces bioactive adipokines, which take part in glucose and lipid metabolism. Considering its endocrine function, the adipose tissue is not a homogeneous gland but a group of a few glands which act differently. Studies on the secretory function of WAT began in 1994 after discovery of leptin known as the satiation hormone, which regulates body energy homeostasis and maintainence of body mass. Apart from leptin, the following belong to adipokines: adiponectin, resistin, apelin, visfatin and cytokines: TNF and IL 6. Adiponectin is a polypeptide hormone of antidiabetic, anti-inflammatory and anti-atherogenic activity. It plays a key role in carbohydrate and fat metabolism. Resistin exerts a counter effect compared to adiponectin and its physiological role is to maintain fasting glycaemia. Visfatin stimulates insulin secretion and increases insulin sensitivity and glucose uptake by muscle cells and adipocytes. Apelin probably increases the insulin sensitivity of tissues. TNF evokes insulin resistance by blocking insulin receptors and inhibits insulin secretion. Approximately 30% of circulating IL 6 comes from adipose tissue. It causes insulin resistance by decreasing the expression of insulin receptors, decreases adipogenesis and adiponectin and visfatin secretion, and stimulates hepatic gluconeogenesis. In 2004, Bays introduced the notion of adiposopathy, defined as dysfunction of the adipose tissue, whose main feature is insulin and leptin resistance as well as the production of inflammatory cytokines: TNF and IL 6 and monocyte chemoattractant protein. This means that excess of adipose tissue, especially visceral adipose tissue, leads to the development of a chronic subclinical

  2. Assessment of brown adipose tissue function.

    PubMed

    Virtue, Sam; Vidal-Puig, Antonio

    2013-01-01

    In this review we discuss practical considerations for the assessment of brown adipose tissue in rodent models, focusing on mice. The central aim of the review is to provide a critical appraisal of the utility of specialized techniques for assessing brown adipose tissue function in vivo. We cover several of the most common specialized methods for analysing brown adipose tissue function in vivo, including assessment of maximal thermogenic capacity by indirect calorimetry and the measurement of sympathetic tone to brown adipose tissue. While these techniques are powerful, they are not readily available to all laboratories; therefore we also cover several simple measurements that, particularly in combination, can be used to determine if a mouse model is likely to have alterations in brown adipose tissue function. Such techniques include: pair feeding, analysis of brown adipose tissue lipid content and mRNA and protein markers of brown adipose tissue activation.

  3. Assessment of brown adipose tissue function

    PubMed Central

    Virtue, Sam; Vidal-Puig, Antonio

    2013-01-01

    In this review we discuss practical considerations for the assessment of brown adipose tissue in rodent models, focusing on mice. The central aim of the review is to provide a critical appraisal of the utility of specialized techniques for assessing brown adipose tissue function in vivo. We cover several of the most common specialized methods for analysing brown adipose tissue function in vivo, including assessment of maximal thermogenic capacity by indirect calorimetry and the measurement of sympathetic tone to brown adipose tissue. While these techniques are powerful, they are not readily available to all laboratories; therefore we also cover several simple measurements that, particularly in combination, can be used to determine if a mouse model is likely to have alterations in brown adipose tissue function. Such techniques include: pair feeding, analysis of brown adipose tissue lipid content and mRNA and protein markers of brown adipose tissue activation. PMID:23760815

  4. Adipose tissue: cell heterogeneity and functional diversity.

    PubMed

    Esteve Ràfols, Montserrat

    2014-02-01

    There are two types of adipose tissue in the body whose function appears to be clearly differentiated. White adipose tissue stores energy reserves as fat, whereas the metabolic function of brown adipose tissue is lipid oxidation to produce heat. A good balance between them is important to maintain energy homeostasis. The concept of white adipose tissue has radically changed in the past decades, and is now considered as an endocrine organ that secretes many factors with autocrine, paracrine, and endocrine functions. In addition, we can no longer consider white adipose tissue as a single tissue, because it shows different metabolic profiles in its different locations, with also different implications. Although the characteristic cell of adipose tissue is the adipocyte, this is not the only cell type present in adipose tissue, neither the most abundant. Other cell types in adipose tissue described include stem cells, preadipocytes, macrophages, neutrophils, lymphocytes, and endothelial cells. The balance between these different cell types and their expression profile is closely related to maintenance of energy homeostasis. Increases in adipocyte size, number and type of lymphocytes, and infiltrated macrophages are closely related to the metabolic syndrome diseases. The study of regulation of proliferation and differentiation of preadipocytes and stem cells, and understanding of the interrelationship between the different cell types will provide new targets for action against these diseases. Copyright © 2012 SEEN. Published by Elsevier Espana. All rights reserved.

  5. Mitochondria and endocrine function of adipose tissue.

    PubMed

    Medina-Gómez, Gema

    2012-12-01

    Excess of adipose tissue is accompanied by an increase in the risk of developing insulin resistance, type 2 diabetes (T2D) and other complications. Nevertheless, total or partial absence of fat or its accumulation in other tissues (lipotoxicity) is also associated to these complications. White adipose tissue (WAT) was traditionally considered a metabolically active storage tissue for lipids while brown adipose tissue (BAT) was considered as a thermogenic adipose tissue with higher oxidative capacity. Nowadays, WAT is also considered an endocrine organ that contributes to energy homeostasis. Experimental evidence tends to link the malfunction of adipose mitochondria with the development of obesity and T2D. This review discusses the importance of mitochondrial function in adipocyte biology and the increased evidences of mitochondria dysfunction in these epidemics. New strategies targeting adipocyte mitochondria from WAT and BAT are also discussed as therapies against obesity and its complications in the near future.

  6. Does bariatric surgery improve adipose tissue function?

    PubMed Central

    Frikke-Schmidt, H.; O’Rourke, R. W.; Lumeng, C. N.; Sandoval, D. A.; Seeley, R. J.

    2017-01-01

    Summary Bariatric surgery is currently the most effective treatment for obesity. Not only do these types of surgeries produce significant weight loss but also they improve insulin sensitivity and whole body metabolic function. The aim of this review is to explore how altered physiology of adipose tissue may contribute to the potent metabolic effects of some of these procedures. This includes specific effects on various fat depots, the function of individual adipocytes and the interaction between adipose tissue and other key metabolic tissues. Besides a dramatic loss of fat mass, bariatric surgery shifts the distribution of fat from visceral to the subcutaneous compartment favoring metabolic improvement. The sensitivity towards lipolysis controlled by insulin and catecholamines is improved, adipokine secretion is altered and local adipose inflammation as well as systemic inflammatory markers decreases. Some of these changes have been shown to be weight loss independent, and novel hypothesis for these effects includes include changes in bile acid metabolism, gut microbiota and central regulation of metabolism. In conclusion bariatric surgery is capable of improving aspects of adipose tissue function and do so in some cases in ways that are not entirely explained by the potent effect of surgery. PMID:27272117

  7. Sex dimorphism and depot differences in adipose tissue function

    PubMed Central

    White, Ursula A.; Tchoukalova, Yourka D.

    2013-01-01

    Obesity, characterized by excessive adiposity, is a risk factor for many metabolic pathologies, such as Type 2 Diabetes mellitus (T2DM). Numerous studies have shown that adipose tissue distribution may be a greater predictor of metabolic health. Upper-body fat (visceral and subcutaneous abdominal) is commonly associated with the unfavorable complications of obesity, while lower-body fat (gluteal-femoral) may be protective. Current research investigations are focused on analyzing the metabolic properties of adipose tissue, in order to better understand the mechanisms that regulate fat distribution in both men and women. This review will highlight the adipose tissue depot- and sex- dependent differences in white adipose tissue function, including adipogenesis, adipose tissue developmental patterning, the storage and release of fatty acids, and secretory function. PMID:23684841

  8. Hypoxia and adipose tissue function and dysfunction in obesity.

    PubMed

    Trayhurn, Paul

    2013-01-01

    The rise in the incidence of obesity has led to a major interest in the biology of white adipose tissue. The tissue is a major endocrine and signaling organ, with adipocytes, the characteristic cell type, secreting a multiplicity of protein factors, the adipokines. Increases in the secretion of a number of adipokines occur in obesity, underpinning inflammation in white adipose tissue and the development of obesity-associated diseases. There is substantial evidence, particularly from animal studies, that hypoxia develops in adipose tissue as the tissue mass expands, and the reduction in Po(2) is considered to underlie the inflammatory response. Exposure of white adipocytes to hypoxic conditions in culture induces changes in the expression of >1,000 genes. The secretion of a number of inflammation-related adipokines is upregulated by hypoxia, and there is a switch from oxidative metabolism to anaerobic glycolysis. Glucose utilization is increased in hypoxic adipocytes with corresponding increases in lactate production. Importantly, hypoxia induces insulin resistance in fat cells and leads to the development of adipose tissue fibrosis. Many of the responses of adipocytes to hypoxia are initiated at Po(2) levels above the normal physiological range for adipose tissue. The other cell types within the tissue also respond to hypoxia, with the differentiation of preadipocytes to adipocytes being inhibited and preadipocytes being transformed into leptin-secreting cells. Overall, hypoxia has pervasive effects on the function of adipocytes and appears to be a key factor in adipose tissue dysfunction in obesity.

  9. Metabolic syndrome - dysregulation of adipose tissue endocrine function.

    PubMed

    Horská, Kateřina; Kučerová, Jana; Suchý, Pavel; Kotolová, Hana

    2014-08-01

    Metabolic syndrome, acondition increasing cardiovascular morbidity, mortality and risk for diabetes mellitus type 2, is currently worldwide reaching epidemic proportions. This complex disorder represents an urgent challenge for new pharmacotherapeutic strategies formulation. Pathophysiological mechanisms underlying metabolic syndrome are not completely understood, nevertheless growing evidence is supporting the hypothesis that multiple metabolic dysregulations do contribute to its development. Apotential target for pharmacological intervention is considered to be dysregulation of adipose tissue endocrine/paracrine function. Specific adipokines, proteins secreted by the adipose tissue, with some pleiotropic effects, have been identified with strong association to regulation of energy metabolism, appetite, insulin signaling, tissue insulin sensitivity and the proinflammatory state related to metabolic syndrome. The aim of this paper is to provide a brief overview of endocrine/paracrine functions of the adipose tissue with regard to metabolic syndrome development and pathophysiology and particular adipokines as potential targets for innovative pharmacotherapeutic approaches.

  10. Functions of AMP-activated protein kinase in adipose tissue

    PubMed Central

    Daval, Marie; Foufelle, Fabienne; Ferré, Pascal

    2006-01-01

    AMP-activated protein kinase (AMPK) is involved in cellular energy homeostasis. Its functions have been extensively studied in muscles and liver. AMPK stimulates pathways which increase energy production (glucose transport, fatty acid oxidation) and switches off pathways which consume energy (lipogenesis, protein synthesis, gluconeogenesis). This has led to the concept that AMPK has an interesting pharmaceutical potential in situations of insulin resistance and it is indeed the target of existing drugs and hormones which improve insulin sensitivity. Adipose tissue is a key player in energy metabolism through the release of substrates and hormones involved in metabolism and insulin sensitivity. Activation of AMPK in adipose tissue can be achieved through situations such as fasting and exercise. Leptin and adiponectin as well as hypoglycaemic drugs are activators of adipose tissue AMPK. This activation probably involves changes in the AMP/ATP ratio and the upstream kinase LKB1. When activated, AMPK limits fatty acid efflux from adipocytes and favours local fatty acid oxidation. Since fatty acids have a key role in insulin resistance, especially in muscles, activating AMPK in adipose tissue might be found to be beneficial in insulin-resistant states, particularly as AMPK activation also reduces cytokine secretion in adipocytes. PMID:16709632

  11. Underlying functional genomics of fat deposition in adipose tissue.

    PubMed

    Bakhtiarizadeh, Mohammad Reza; Moradi-Shahrbabak, Mohammad; Ebrahimie, Esmaeil

    2013-05-25

    The objective of this study was to gain insight into the underlying mechanisms of fat deposition. Two sheep breeds with large fat-tail (Lori-Bakhtiari) and with thin-tail (Zel) were used as models. To determine important and key candidate lipid metabolism related genes, comparative genomic approaches were employed. Gene expression profiles of adipose tissues were analyzed in human, pig, and cattle by express sequence tag (EST) analysis. EST analysis determined 65, 102 and 125 transcripts in human, pig and cattle respectively with at least 10 fold over-expression in the adipose tissue. Based on our comparative functional genomic analysis, seven genes were more abundant and common in investigated mammalian adipose tissues promising a conserved novel gene network in mammalian lipid metabolism. The candidate genes including fatty acid binding protein 4 (FABP4), fatty acid synthase (FASN), Stearoyl-CoA desaturase (SCD) and Lipoprotein lipase (LPL) were selected for further gene expression investigation within two sheep breeds. The real time PCR results showed that among the genes tested, FABP4 was expressed at higher levels than the others. The expression of FABP4 was significantly higher in the fat-tail of Lori-Bakhtiari than in the fat-tail and visceral adipose tissues of Zel (P<0.05). The findings suggest that the FABP4 gene expression in the fat-tail is an important index of fat deposition. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. The development and endocrine functions of adipose tissue.

    PubMed

    Poulos, Sylvia P; Hausman, Dorothy B; Hausman, Gary J

    2010-07-08

    White adipose tissue is a mesenchymal tissue that begins developing in the fetus. Classically known for storing the body's fuel reserves, adipose tissue is now recognized as an endocrine organ. As such, the secretions from adipose tissue are known to affect several systems such as the vascular and immune systems and play major roles in metabolism. Numerous studies have shown nutrient or hormonal manipulations can greatly influence adipose tissue development. In addition, the associations between various disease states, such as insulin resistance and cardiovascular disease, and disregulation of adipose tissue seen in epidemiological and intervention studies are great. Evaluation of known adipokines suggests these factors secreted from adipose tissue play roles in several pathologies. As the identification of more adipokines and determination of their role in biological systems, and the interactions between adipocytes and other cells types continues, there is little doubt that we will gain a greater appreciation for a tissue once thought to simply store excess energy.

  13. Brown adipose tissue: physiological function and evolutionary significance.

    PubMed

    Oelkrug, R; Polymeropoulos, E T; Jastroch, M

    2015-08-01

    In modern eutherian (placental) mammals, brown adipose tissue (BAT) evolved as a specialized thermogenic organ that is responsible for adaptive non-shivering thermogenesis (NST). For NST, energy metabolism of BAT mitochondria is increased by activation of uncoupling protein 1 (UCP1), which dissipates the proton motive force as heat. Despite the presence of UCP1 orthologues prior to the divergence of teleost fish and mammalian lineages, UCP1's significance for thermogenic adipose tissue emerged at later evolutionary stages. Recent studies on the presence of BAT in metatherians (marsupials) and eutherians of the afrotherian clade provide novel insights into the evolution of adaptive NST in mammals. In particular studies on the 'protoendothermic' lesser hedgehog tenrec (Afrotheria) suggest an evolutionary scenario linking BAT to the onset of eutherian endothermy. Here, we review the physiological function and distribution of BAT in an evolutionary context by focusing on the latest research on phylogenetically distinct species.

  14. Physiological functions of Vitamin D in adipose tissue.

    PubMed

    Abbas, Manal A

    2017-01-01

    Adipose tissue has long been identified as the major site of vitamin D storage. Recent studies have demonstrated that VDR and vitamin D metabolizing enzymes are expressed in adipocytes. Furthermore, it has been shown that vitamin D regulates adipogenic gene expression as well as adipocyte apoptosis. Vitamin D is active in adipocytes at all levels. It interacts with membrane receptors, adaptor molecules, and nuclear coregulator proteins. Several functions of unliganded nVDR were discovered by studying human samples from patients having hereditary vitamin D resistant rickets, transgenic mice overexpressing the VDR and VDR knockout mice. Through its genomic action, vitamin D participates in the regulation of energy metabolism by controlling the expression of uncoupling proteins. In vitro, vitamin D stimulates lipogenesis and inhibits lipolysis by interacting with mVDR. mVDR is present in caveolae of the plasma membrane and is the same as the classic nVDR. In addition, vitamin D affects directly the expression of the appetite regulating hormone, leptin. Some researchers reported also that vitamin D regulates the expression of the insulin sensitizing hormone, adiponectin. Vitamin D reduced cytokine release and adipose tissue inflammation through the inhibition of NF-κB signaling. Scientific research investigating the role of adipose tissue resident immune cells in the pathogenesis of obesity-associated inflammation is scarce. Obesity is associated with vitamin D deficiency. However there is no scientific evidence to prove that vitamin D deficiency predispose to obesity. Vitamin D supplementation may prevent obesity but it does not lead to weight loss in obese subjects. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Toxicological Function of Adipose Tissue: Focus on Persistent Organic Pollutants

    PubMed Central

    La Merrill, Michele; Emond, Claude; Kim, Min Ji; Antignac, Jean-Philippe; Le Bizec, Bruno; Clément, Karine; Birnbaum, Linda S.

    2012-01-01

    Background: Adipose tissue (AT) is involved in several physiological functions, including metabolic regulation, energy storage, and endocrine functions. Objectives: In this review we examined the evidence that an additional function of AT is to modulate persistent organic pollutant (POP) toxicity through several mechanisms. Methods: We reviewed the literature on the interaction of AT with POPs to provide a comprehensive model for this additional function of AT. Discussion: As a storage compartment for lipophilic POPs, AT plays a critical role in the toxicokinetics of a variety of drugs and pollutants, in particular, POPs. By sequestering POPs, AT can protect other organs and tissues from POPs overload. However, this protective function could prove to be a threat in the long run. The accumulation of lipophilic POPs will increase total body burden. These accumulated POPs are slowly released into the bloodstream, and more so during weight loss. Thus, AT constitutes a continual source of internal exposure to POPs. In addition to its buffering function, AT is also a target of POPs and may mediate part of their metabolic effects. This is particularly relevant because many POPs induce obesogenic effects that may lead to quantitative and qualitative alterations of AT. Some POPs also induce a proinflammatory state in AT, which may lead to detrimental metabolic effects. Conclusion: AT appears to play diverse functions both as a modulator and as a target of POPs toxicity. PMID:23221922

  16. Molecular clock integration of brown adipose tissue formation and function

    PubMed Central

    Nam, Deokhwa; Yechoor, Vijay K.; Ma, Ke

    2016-01-01

    Abstract The circadian clock is an essential time-keeping mechanism that entrains internal physiology to environmental cues. Despite the well-established link between the molecular clock and metabolic homeostasis, an intimate interplay between the clock machinery and the metabolically active brown adipose tissue (BAT) is only emerging. Recently, we came to appreciate that the formation and metabolic functions of BAT, a key organ for body temperature maintenance, are under an orchestrated circadian clock regulation. Two complementary studies from our group uncover that the cell-intrinsic clock machinery exerts concerted control of brown adipogenesis with consequent impacts on adaptive thermogenesis, which adds a previously unappreciated temporal dimension to the regulatory mechanisms governing BAT development and function. The essential clock transcriptional activator, Bmal1, suppresses adipocyte lineage commitment and differentiation, whereas the clock repressor, Rev-erbα, promotes these processes. This newly discovered temporal mechanism in fine-tuning BAT thermogenic capacity may enable energy utilization and body temperature regulation in accordance with external timing signals during development and functional recruitment. Given the important role of BAT in whole-body metabolic homeostasis, pharmacological interventions targeting the BAT-modulatory activities of the clock circuit may offer new avenues for the prevention and treatment of metabolic disorders, particularly those associated with circadian dysregulation. PMID:27385482

  17. Acute Hypercortisolemia Exerts Depot-Specific Effects on Abdominal and Femoral Adipose Tissue Function.

    PubMed

    Manolopoulos, Konstantinos N; O'Reilly, Michael W; Bujalska, Iwona J; Tomlinson, Jeremy W; Arlt, Wiebke

    2017-04-01

    Glucocorticoids have pleiotropic metabolic functions, and acute glucocorticoid excess affects fatty acid metabolism, increasing systemic lipolysis. Whether glucocorticoids exert adipose tissue depot-specific effects remains unclear. To provide an in vivo assessment of femoral and abdominal adipose tissue responses to acute glucocorticoid administration. Nine healthy male volunteers were studied on two occasions, after a hydrocortisone infusion (0.2 mg/kg/min for 14 hours) and a saline infusion, respectively, given in randomized double-blind order. The subjects were studied in the fasting state and after a 75-g glucose drink with an in vivo assessment of femoral adipose tissue blood flow (ATBF) using radioactive xenon washout and of lipolysis and glucose uptake using the arteriovenous difference technique. In a separate study (same infusion design), eight additional healthy male subjects underwent assessment of fasting abdominal ATBF and lipolysis only. Lipolysis was assessed as the net release of nonesterified fatty acids (NEFAs) from femoral and abdominal subcutaneous adipose tissue. Acute hypercortisolemia significantly increased basal and postprandial ATBF in femoral adipose tissue, but the femoral net NEFA release did not change. In abdominal adipose tissue, hypercortisolemia induced substantial increases in basal ATBF and NEFA release. Acute hypercortisolemia induces differential lipolysis and ATBF responses in abdominal and femoral adipose tissue, suggesting depot-specific glucocorticoid effects. Abdominal, but not femoral, adipose tissue contributes to the hypercortisolemia-induced systemic NEFA increase, with likely contributions from other adipose tissue sources and intravascular triglyceride hydrolysis.

  18. Androgen Effects on Adipose Tissue Architecture and Function in Nonhuman Primates

    PubMed Central

    Varlamov, Oleg; White, Ashley E.; Carroll, Julie M.; Bethea, Cynthia L.; Reddy, Arubala; Slayden, Ov; O'Rourke, Robert W.

    2012-01-01

    The differential association of hypoandrogenism in men and hyperandrogenism in women with insulin resistance and obesity suggests that androgens may exert sex-specific effects on adipose and other tissues, although the underlying mechanisms remain poorly understood. Moreover, recent studies also suggest that rodents and humans may respond differently to androgen imbalance. To achieve better insight into clinically relevant sex-specific mechanisms of androgen action, we used nonhuman primates to investigate the direct effects of gonadectomy and hormone replacement on white adipose tissue. We also employed a novel ex vivo approach that provides a convenient framework for understanding of adipose tissue physiology under a controlled tissue culture environment. In vivo androgen deprivation of males did not result in overt obesity or insulin resistance but did induce the appearance of very small, multilocular white adipocytes. Testosterone replacement restored normal cell size and a unilocular phenotype and stimulated adipogenic gene transcription and improved insulin sensitivity of male adipose tissue. Ex vivo studies demonstrated sex-specific effects of androgens on adipocyte function. Female adipose tissue treated with androgens displayed elevated basal but reduced insulin-dependent fatty acid uptake. Androgen-stimulated basal uptake was greater in adipose tissue of ovariectomized females than in adipose tissue of intact females and ovariectomized females replaced with estrogen and progesterone in vivo. Collectively, these data demonstrate that androgens are essential for normal adipogenesis in males and can impair essential adipocyte functions in females, thus strengthening the experimental basis for sex-specific effects of androgens in adipose tissue. PMID:22547568

  19. Androgen effects on adipose tissue architecture and function in nonhuman primates.

    PubMed

    Varlamov, Oleg; White, Ashley E; Carroll, Julie M; Bethea, Cynthia L; Reddy, Arubala; Slayden, Ov; O'Rourke, Robert W; Roberts, Charles T

    2012-07-01

    The differential association of hypoandrogenism in men and hyperandrogenism in women with insulin resistance and obesity suggests that androgens may exert sex-specific effects on adipose and other tissues, although the underlying mechanisms remain poorly understood. Moreover, recent studies also suggest that rodents and humans may respond differently to androgen imbalance. To achieve better insight into clinically relevant sex-specific mechanisms of androgen action, we used nonhuman primates to investigate the direct effects of gonadectomy and hormone replacement on white adipose tissue. We also employed a novel ex vivo approach that provides a convenient framework for understanding of adipose tissue physiology under a controlled tissue culture environment. In vivo androgen deprivation of males did not result in overt obesity or insulin resistance but did induce the appearance of very small, multilocular white adipocytes. Testosterone replacement restored normal cell size and a unilocular phenotype and stimulated adipogenic gene transcription and improved insulin sensitivity of male adipose tissue. Ex vivo studies demonstrated sex-specific effects of androgens on adipocyte function. Female adipose tissue treated with androgens displayed elevated basal but reduced insulin-dependent fatty acid uptake. Androgen-stimulated basal uptake was greater in adipose tissue of ovariectomized females than in adipose tissue of intact females and ovariectomized females replaced with estrogen and progesterone in vivo. Collectively, these data demonstrate that androgens are essential for normal adipogenesis in males and can impair essential adipocyte functions in females, thus strengthening the experimental basis for sex-specific effects of androgens in adipose tissue.

  20. Prolactin (PRL) in adipose tissue: regulation and functions.

    PubMed

    Ben-Jonathan, Nira; Hugo, Eric

    2015-01-01

    New information concerning the effects of prolactin (PRL) on metabolic processes warrants reevaluation of its overall metabolic actions. PRL affects metabolic homeostasis by regulating key enzymes and transporters associated with glucose and lipid metabolism in several target organs. In the lactating mammary gland, PRL increases the production of milk proteins, lactose, and lipids. In adipose tissue, PRL generally suppresses lipid storage and adipokine release and affect adipogenesis. A specific case is made for PRL in the human breast and adipose tissues, where it acts as a circulating hormone and an autocrine/paracrine factor. Although its overall effects on body composition are both modest and species-specific, PRL may be involved in the manifestation of insulin resistance.

  1. Effects of Ang II receptor blocker irbesartan on adipose tissue function in mice with metabolic disorders.

    PubMed

    Maeda, Akinobu; Tamura, Kouichi; Wakui, Hiromichi; Ohsawa, Masato; Azushima, Kengo; Uneda, Kazushi; Kobayashi, Ryu; Tsurumi-Ikeya, Yuko; Kanaoka, Tomohiko; Dejima, Toru; Ohki, Koji; Haku, Sona; Yamashita, Akio; Umemura, Satoshi

    2014-01-01

    Recent studies indicate that the functional renin-angiotensin system (RAS) exists in the adipose tissue. The adipose tissue RAS is proposed in the pathophysiology of metabolic disorders. In the present study, we examined therapeutic effects of irbesartan, an angiotensin II (Ang II) type 1 receptor (AT1R)-specific blocker, in genetically obese diabetic KKAy mice, a model of human metabolic disorders without any dietary loading, with our focus on the analysis on possible effect of irbesartan on the adipose tissue. The treatment with irbesartan significantly lowered systolic blood pressure with a concomitant decrease in body weight in KKAy mice. In addition, irbesartan significantly decreased the adipose leptin mRNA expression and tended to decrease IL-6 mRNA expression in the adipose tissue of KKAy mice. Furthermore irbesartan preserved the adipose gene expression of AT1R-associated protein (ATRAP), an endogenous inhibitory molecule of tissue AT1R signaling, with a concomitant tendency of up-regulation of adipose tissue ATRAP/AT1R ratio. Collectively, these results suggest that the irbesartan-induced beneficial suppressive effect on the leptin-IL-6 axis in the adipose tissue in KKAy mice is partly mediated by a trend of up-regulation of the adipose ATRAP/AT1R ratio as one of pleiotropic effects of irbesartan.

  2. Adipose Tissue Engineering for Soft Tissue Regeneration

    PubMed Central

    Choi, Jennifer H.; Gimble, Jeffrey M.; Lee, Kyongbum; Marra, Kacey G.; Rubin, J. Peter; Yoo, James J.; Vunjak-Novakovic, Gordana

    2010-01-01

    Current treatment modalities for soft tissue defects caused by various pathologies and trauma include autologous grafting and commercially available fillers. However, these treatment methods present a number of challenges and limitations, such as donor-site morbidity and volume loss over time. As such, improved therapeutic modalities need to be developed. Tissue engineering techniques offer novel solutions to these problems through development of bioactive tissue constructs that can regenerate adipose tissue in both structure and function. Recently, a number of studies have been designed to explore various methods to engineer human adipose tissue. This review will focus on these developments in the area of adipose tissue engineering for soft tissue replacement. The physiology of adipose tissue and current surgical therapies used to replace lost tissue volume, specifically in breast tissue, are introduced, and current biomaterials, cell sources, and tissue culture strategies are discussed. We discuss future areas of study in adipose tissue engineering. PMID:20166810

  3. A worm of one's own: how helminths modulate host adipose tissue function and metabolism.

    PubMed

    Guigas, Bruno; Molofsky, Ari B

    2015-09-01

    Parasitic helminths have coexisted with human beings throughout time. Success in eradicating helminths has limited helminth-induced morbidity and mortality but is also correlated with increasing rates of 'western' diseases, including metabolic syndrome and type 2 diabetes. Recent studies in mice describe how type 2 immune cells, traditionally associated with helminth infection, maintain adipose tissue homeostasis and promote adipose tissue beiging, protecting against obesity and metabolic dysfunction. Here, we review these studies and discuss how helminths and helminth-derived molecules may modulate these physiologic pathways to improve metabolic functions in specific tissues, such as adipose and liver, as well as at the whole-organism level.

  4. An atlas of G-protein coupled receptor expression and function in human subcutaneous adipose tissue.

    PubMed

    Amisten, Stefan; Neville, Matt; Hawkes, Ross; Persaud, Shanta J; Karpe, Fredrik; Salehi, Albert

    2015-02-01

    G-protein coupled receptors (GPCRs) are involved in the regulation of adipose tissue function, but the total number of GPCRs expressed by human subcutaneous adipose tissue, as well as their function and interactions with drugs, is poorly understood. We have constructed an atlas of all GPCRs expressed by human subcutaneous adipose tissue: the 'adipose tissue GPCRome', to support the exploration of novel control nodes in metabolic and endocrine functions. This atlas describes how adipose tissue GPCRs regulate lipolysis, insulin resistance and adiponectin and leptin secretion. We also discuss how adipose tissue GPCRs interact with their endogenous ligands and with GPCR-targeting drugs, with a focus on how drug/receptor interactions may affect lipolysis, and present a model predicting how GPCRs with unknown effects on lipolysis might modulate cAMP-regulated lipolysis. Subcutaneous adipose tissue expresses 163 GPCRs, a majority of which have unknown effects on lipolysis, insulin resistance and adiponectin and leptin secretion. These GPCRs are activated by 180 different endogenous ligands, and are the targets of a large number of clinically used drugs. We identified 119 drugs, acting on 23 GPCRs, that are predicted to stimulate lipolysis and 173 drugs, acting on 25 GPCRs, that are predicted to inhibit lipolysis. This atlas highlights knowledge gaps in the current understanding of adipose tissue GPCR function, and identifies GPCR/ligand/drug interactions that might affect lipolysis, which is important for understanding and predicting metabolic side effects of drugs. This approach may aid in the design of new, safer therapeutic agents, with fewer undesired effects on lipid homeostasis. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. The role of sex steroids in white adipose tissue adipocyte function.

    PubMed

    Newell-Fugate, A E

    2017-04-01

    With the increasing knowledge that gender influences normal physiology, much biomedical research has begun to focus on the differential effects of sex on tissue function. Sexual dimorphism in mammals is due to the combined effects of both genetic and hormonal factors. Hormonal factors are mutable particularly in females in whom the estrous cycle dominates the hormonal milieu. Given the severity of the obesity epidemic and the fact that there are differences in the obesity rates in men and women, the role of sex in white adipose tissue function is being recognized as increasingly important. Although sex differences in white adipose tissue distribution are well established, the mechanisms affecting differential function of adipocytes within white adipose tissue in males and females remain largely understudied and poorly understood. One of the largest differences in the endocrine environment in males and females is the concentration of circulating androgens and estrogens. This review examines the effects of androgens and estrogens on lipolysis/lipogenesis, adipocyte differentiation, insulin sensitivity and adipokine production in adipocytes from white adipose tissue with a specific emphasis on the sexual dimorphism of adipocyte function in white adipose tissue during both health and disease.

  6. Allele Compensation in Tip60+/− Mice Rescues White Adipose Tissue Function In Vivo

    PubMed Central

    Gao, Yuan; Hamers, Nicole; Rakhshandehroo, Maryam; Berger, Ruud; Lough, John; Kalkhoven, Eric

    2014-01-01

    Adipose tissue is a key regulator of energy homestasis. The amount of adipose tissue is largely determined by adipocyte differentiation (adipogenesis), a process that is regulated by the concerted actions of multiple transcription factors and cofactors. Based on in vitro studies in murine 3T3-L1 preadipocytes and human primary preadipocytes, the transcriptional cofactor and acetyltransferase Tip60 was recently identified as an essential adipogenic factor. We therefore investigated the role of Tip60 on adipocyte differentiation and function, and possible consequences on energy homeostasis, in vivo. Because homozygous inactivation results in early embryonic lethality, Tip60+/− mice were used. Heterozygous inactivation of Tip60 had no effect on body weight, despite slightly higher food intake by Tip60+/− mice. No major effects of heterozygous inactivation of Tip60 were observed on adipose tissue and liver, and Tip60+/− displayed normal glucose tolerance, both on a low fat and a high fat diet. While Tip60 mRNA was reduced to 50% in adipose tissue, the protein levels were unaltered, suggesting compensation by the intact allele. These findings indicate that the in vivo role of Tip60 in adipocyte differentiation and function cannot be properly addressed in Tip60+/− mice, but requires the generation of adipose tissue-specific knock out animals or specific knock-in mice. PMID:24870614

  7. Allele compensation in tip60+/- mice rescues white adipose tissue function in vivo.

    PubMed

    Gao, Yuan; Hamers, Nicole; Rakhshandehroo, Maryam; Berger, Ruud; Lough, John; Kalkhoven, Eric

    2014-01-01

    Adipose tissue is a key regulator of energy homestasis. The amount of adipose tissue is largely determined by adipocyte differentiation (adipogenesis), a process that is regulated by the concerted actions of multiple transcription factors and cofactors. Based on in vitro studies in murine 3T3-L1 preadipocytes and human primary preadipocytes, the transcriptional cofactor and acetyltransferase Tip60 was recently identified as an essential adipogenic factor. We therefore investigated the role of Tip60 on adipocyte differentiation and function, and possible consequences on energy homeostasis, in vivo. Because homozygous inactivation results in early embryonic lethality, Tip60+/- mice were used. Heterozygous inactivation of Tip60 had no effect on body weight, despite slightly higher food intake by Tip60+/- mice. No major effects of heterozygous inactivation of Tip60 were observed on adipose tissue and liver, and Tip60+/- displayed normal glucose tolerance, both on a low fat and a high fat diet. While Tip60 mRNA was reduced to 50% in adipose tissue, the protein levels were unaltered, suggesting compensation by the intact allele. These findings indicate that the in vivo role of Tip60 in adipocyte differentiation and function cannot be properly addressed in Tip60+/- mice, but requires the generation of adipose tissue-specific knock out animals or specific knock-in mice.

  8. Omega-3 fatty acids and adipose tissue function in obesity and metabolic syndrome.

    PubMed

    Martínez-Fernández, Leyre; Laiglesia, Laura M; Huerta, Ana E; Martínez, J Alfredo; Moreno-Aliaga, María J

    2015-09-01

    The n-3 long-chain polyunsaturated fatty acids (n-3 PUFAs) such as eicosapentaenoic (EPA) and docosahexaenoic (DHA) have been reported to improve obesity-associated metabolic disorders including chronic inflammation, insulin resistance and dyslipidaemia. Growing evidence exits about adipose tissue as a target in mediating the beneficial effects of these marine n-3 PUFAs in adverse metabolic syndrome manifestations. Therefore, in this manuscript we focus in reviewing the current knowledge about effects of marine n-3 PUFAs on adipose tissue metabolism and secretory functions. This scope includes n-3 PUFAs actions on adipogenesis, lipogenesis and lipolysis as well as on fatty acid oxidation and mitochondrial biogenesis. The effects of n-3 PUFAs on adipose tissue glucose uptake and insulin signaling are also summarized. Moreover, the roles of peroxisome proliferator-activated receptor γ (PPARγ) and AMPK activation in mediating n-3 PUFAs actions on adipose tissue functions are discussed. Finally, the mechanisms underlying the ability of n-3 PUFAs to prevent and/or ameliorate adipose tissue inflammation are also revised, focusing on the role of n-3 PUFAs-derived specialized proresolving lipid mediators such as resolvins, protectins and maresins. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Mechanisms of glucocorticoid-induced insulin resistance: focus on adipose tissue function and lipid metabolism.

    PubMed

    Geer, Eliza B; Islam, Julie; Buettner, Christoph

    2014-03-01

    Glucocorticoids (GCs) are critical in the regulation of the stress response, inflammation and energy homeostasis. Excessive GC exposure results in whole-body insulin resistance, obesity, cardiovascular disease, and ultimately decreased survival, despite their potent anti-inflammatory effects. This apparent paradox may be explained by the complex actions of GCs on adipose tissue functionality. The wide prevalence of oral GC therapy makes their adverse systemic effects an important yet incompletely understood clinical problem. This article reviews the mechanisms by which supraphysiologic GC exposure promotes insulin resistance, focusing in particular on the effects on adipose tissue function and lipid metabolism. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Adipose tissue dysfunction in obesity.

    PubMed

    Blüher, M

    2009-06-01

    The incidence of obesity has increased dramatically during recent decades. Obesity will cause a decline in life expectancy for the first time in recent history due to numerous co-morbid disorders. Adipocyte and adipose tissue dysfunction belong to the primary defects in obesity and may link obesity to several health problems including increased risk of insulin resistance, type 2 diabetes, fatty liver disease, hypertension, dyslipidemia, atherosclerosis, dementia, airway disease and some cancers. However, not all obese individuals develop obesity related metabolic or cardiovascular disorders potentially due to a preserved normal adipose tissue architecture and function. The majority of patients with obesity have an impaired adipose tissue function caused by the interaction of genetic and environmental factors which lead to adipocyte hypertrophy, hypoxia, a variety of stresses and inflammatory processes within adipose tissue. Ectopic fat accumulation including visceral obesity may be considered as a consequence of adipose tissue dysfunction, which is further characterized by changes in the cellular composition, increased lipid storage and impaired insulin sensitivity in adipocytes, and secretion of a proinflammatory, atherogenic, and diabetogenic adipokine pattern. This review focuses on the discussion of mechanisms causing or maintaining impaired adipose tissue function in obesity and potentially linking obesity to its associated disorders. A model is proposed how different pathogenic factors and mechanisms may cause dysfunction of adipose tissue.

  11. Defining dermal adipose tissue.

    PubMed

    Driskell, Ryan R; Jahoda, Colin A B; Chuong, Cheng-Ming; Watt, Fiona M; Horsley, Valerie

    2014-09-01

    Here, we explore the evolution and development of skin-associated adipose tissue with the goal of establishing nomenclature for this tissue. Underlying the reticular dermis, a thick layer of adipocytes exists that encases mature hair follicles in rodents and humans. The association of lipid-filled cells with the skin is found in many invertebrate and vertebrate species. Historically, this layer of adipocytes has been termed subcutaneous adipose, hypodermis and subcutis. Recent data have revealed a common precursor for dermal fibroblasts and intradermal adipocytes during development. Furthermore, the development of adipocytes in the skin is independent from that of subcutaneous adipose tissue development. Finally, the role of adipocytes has been shown to be relevant for epidermal homoeostasis during hair follicle regeneration and wound healing. Thus, we propose a refined nomenclature for the cells and adipose tissue underlying the reticular dermis as intradermal adipocytes and dermal white adipose tissue, respectively.

  12. Agouti expression in human adipose tissue: functional consequences and increased expression in type 2 diabetes.

    PubMed

    Smith, Steven R; Gawronska-Kozak, Barbara; Janderová, Lenka; Nguyen, Taylor; Murrell, Angela; Stephens, Jacqueline M; Mynatt, Randall L

    2003-12-01

    It is well recognized that the agouti/melanocortin system is an important regulator of body weight homeostasis. Given that agouti is expressed in human adipose tissue and that the ectopic expression of agouti in adipose tissue results in moderately obese mice, the link between agouti expression in human adipose tissue and obesity/type 2 diabetes was investigated. Although there was no apparent relationship between agouti mRNA levels and BMI, agouti mRNA levels were significantly elevated in subjects with type 2 diabetes. The regulation of agouti in cultured human adipocytes revealed that insulin did not regulate agouti mRNA, whereas dexamethasone treatment potently increased the levels of agouti mRNA. Experiments with cultured human preadipocytes and with cells obtained from transgenic mice that overexpress agouti demonstrated that melanocortin receptor (MCR) signaling in adipose tissue can regulate both preadipocyte proliferation and differentiation. Taken together, these results reveal that agouti can regulate adipogenesis at several levels and suggest that there are functional consequences of elevated agouti levels in human adipose tissue. The influence of MCR signaling on adipogenesis combined with the well-established role of MCR signaling in the hypothalamus suggest that adipogenesis is coordinately regulated with food intake and energy expenditure.

  13. The Effect of Marine Derived n-3 Fatty Acids on Adipose Tissue Metabolism and Function

    PubMed Central

    Todorčević, Marijana; Hodson, Leanne

    2015-01-01

    Adipose tissue function is key determinant of metabolic health, with specific nutrients being suggested to play a role in tissue metabolism. One such group of nutrients are the n-3 fatty acids, specifically eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3). Results from studies where human, animal and cellular models have been utilised to investigate the effects of EPA and/or DHA on white adipose tissue/adipocytes suggest anti-obesity and anti-inflammatory effects. We review here evidence for these effects, specifically focusing on studies that provide some insight into metabolic pathways or processes. Of note, limited work has been undertaken investigating the effects of EPA and DHA on white adipose tissue in humans whilst more work has been undertaken using animal and cellular models. Taken together it would appear that EPA and DHA have a positive effect on lowering lipogenesis, increasing lipolysis and decreasing inflammation, all of which would be beneficial for adipose tissue biology. What remains to be elucidated is the duration and dose required to see a favourable effect of EPA and DHA in vivo in humans, across a range of adiposity. PMID:26729182

  14. Fatty acid metabolism and the basis of brown adipose tissue function

    PubMed Central

    Calderon-Dominguez, María; Mir, Joan F.; Fucho, Raquel; Weber, Minéia; Serra, Dolors; Herrero, Laura

    2016-01-01

    ABSTRACT Obesity has reached epidemic proportions, leading to severe associated pathologies such as insulin resistance, cardiovascular disease, cancer and type 2 diabetes. Adipose tissue has become crucial due to its involvement in the pathogenesis of obesity-induced insulin resistance, and traditionally white adipose tissue has captured the most attention. However in the last decade the presence and activity of heat-generating brown adipose tissue (BAT) in adult humans has been rediscovered. BAT decreases with age and in obese and diabetic patients. It has thus attracted strong scientific interest, and any strategy to increase its mass or activity might lead to new therapeutic approaches to obesity and associated metabolic diseases. In this review we highlight the mechanisms of fatty acid uptake, trafficking and oxidation in brown fat thermogenesis. We focus on BAT's morphological and functional characteristics and fatty acid synthesis, storage, oxidation and use as a source of energy. PMID:27386151

  15. Visceral and subcutaneous adipose tissue express and secrete functional alpha2hsglycoprotein (fetuin a) especially in obesity.

    PubMed

    Pérez-Sotelo, Diego; Roca-Rivada, Arturo; Larrosa-García, María; Castelao, Cecilia; Baamonde, Iván; Baltar, Javier; Crujeiras, Ana Belen; Seoane, Luisa María; Casanueva, Felipe F; Pardo, María

    2017-02-01

    The secretion of the hepatokine alpha-2-Heremans-Schmid glycoprotein/Fetuin A, implicated in pathological processes including systemic insulin resistance, by adipose tissue has been recently described. Thus, we have recently identified its presence in white adipose tissue secretomes by mass spectrometry. However, the secretion pattern and function of adipose-derived alpha-2-Heremans-Schmid glycoprotein are poorly understood. The aim of this study is to evaluate the expression and secretion of total and active phosphorylated alpha-2-Heremans-Schmid glycoprotein by adipose tissue from visceral and subcutaneous localizations in animals at different physiological and nutritional status including anorexia and obesity. Alpha-2-Heremans-Schmid glycoprotein expression and secretion in visceral adipose tissue and subcutaneous adipose tissue explants from animals under fasting and exercise training, at pathological situations such as anorexia and obesity, and from human obese individuals were assayed by immunoblotting, quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. We reveal that visceral adipose tissue expresses and secretes more alpha-2-Heremans-Schmid glycoprotein than subcutaneous adipose tissue, and that this secretion is diminished after fasting and exercise training. Visceral adipose tissue from anorectic animals showed reduced alpha-2-Heremans-Schmid glycoprotein secretion; on the contrary, alpha-2-Heremans-Schmid glycoprotein is over-secreted by visceral adipose tissue in the occurrence of obesity. While secretion of active-PhophoSer321α2HSG by visceral adipose tissue is independent of body mass index, we found that the fraction of active-alpha-2-Heremans-Schmid glycoprotein secreted by subcutaneous adipose tissue increments significantly in situations of obesity. Functional studies show that the inhibition of adipose-derived alpha-2-Heremans-Schmid glycoprotein increases insulin sensitivity in differentiated adipocytes. In

  16. The role of JAK-STAT signaling in adipose tissue function.

    PubMed

    Richard, Allison J; Stephens, Jacqueline M

    2014-03-01

    Adipocytes play important roles in lipid storage, energy homeostasis and whole body insulin sensitivity. The JAK-STAT (Janus Kinase-Signal Transducer and Activator of Transcription) pathway mediates a variety of physiological processes including development, hematopoiesis, and inflammation. Although the JAK-STAT signaling pathway occurs in all cells, this pathway can mediate cell specific responses. Studies in the last two decades have identified hormones and cytokines that activate the JAK-STAT signaling pathway. These cytokines and hormones have profound effects on adipocytes. The content of this review will introduce the types of adipocytes and immune cells that make up adipose tissue, the impact of obesity on adipose cellular composition and function, and the general constituents of the JAK-STAT pathway and how its activators regulate adipose tissue development and physiology. A summary of the identification of STAT target genes in adipocytes reveals how these transcription factors impact various areas of adipocyte metabolism including insulin action, modulation of lipid stores, and glucose homeostasis. Lastly, we will evaluate exciting new data linking the JAK-STAT pathway and brown adipose tissue and consider the future outlook in this area of investigation. This article is part of a Special Issue entitled: Modulation of Adipose Tissue in Health and Disease. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  17. Gastric bypass simultaneously improves adipose tissue function and insulin-dependent type 2 diabetes mellitus.

    PubMed

    Billeter, Adrian T; Vittas, Spiros; Israel, Barbara; Scheurlen, Katharina M; Hidmark, Asa; Fleming, Thomas H; Kopf, Stefan; Büchler, Markus W; Müller-Stich, Beat P

    2017-07-09

    The underlying causes of type 2 diabetes (T2DM) remain poorly understood. Adipose tissue dysfunction with high leptin, inflammation, and increased oxidative stress may play a pivotal role in T2DM development in obese patients. Little is known about the changes in the adipose tissue after Roux-Y gastric bypass (RYGB) in non-severely obese patients (BMI < 35 kg/m(2)) and since these patients have more T2DM-associated complications than obese patients ("obesity paradox"), we investigated changes in adipose tissue function in a cohort of BMI <35 kg/m(2) with insulin-dependent T2DM after RYGB surgery which resolves T2DM. Twenty patients with insulin-dependent T2DM and BMI <35 kg/m(2) underwent RYGB. Insulin-resistance, leptin, oxidative stress, and cytokines were determined over 24 months. Expression of cytokines and NF-kappaB pathway genes were measured in leukocytes (PBMC). Adipose tissue inflammation was examined histologically preoperatively and 24 months after RGYB in subcutaneous adipose tissue. Insulin-resistance, leptin, oxidative stress as well as adipose tissue inflammation decreased significantly after RYGB. Similarly, systemic inflammation was reduced and peripheral blood mononuclear cells (PBMCs) were reprogrammed towards an M2-type inflammation. Loss of BMI correlated with leptin levels (r = 0.891, p < 0.0001), insulin resistance (r = 0.527, p = 0.003), and oxidative stress (r = 0.592, p = 0.016). Leptin correlated with improved insulin resistance (r = 0.449, p = 0.032) while reduced leptin showed a strong association with improved oxidative stress (r = 0.809, p = 0.001). Lastly, reduced oxidative stress correlated strongly with improved insulin-resistance (r = 0.776, p = 0.001). RYGB improves adipose tissue function and inflammation. Leptin as marker for adipose tissue dysfunction may be the mediating factor between insulin resistance and oxidative stress and thereby likely improving T2DM.

  18. [Human brown adipose tissue].

    PubMed

    Virtanen, Kirsi A; Nuutila, Pirjo

    2015-01-01

    Adult humans have heat-producing and energy-consuming brown adipose tissue in the clavicular region of the neck. There are two types of brown adipose cells, the so-called classic and beige adipose cells. Brown adipose cells produce heat by means of uncoupler protein 1 (UCP1) from fatty acids and sugar. By applying positron emission tomography (PET) measuring the utilization of sugar, the metabolism of brown fat has been shown to multiply in the cold, presumably influencing energy consumption. Active brown fat is most likely present in young adults, persons of normal weight and women, least likely in obese persons.

  19. Regulation of metabolic health and adipose tissue function by group 2 innate lymphoid cells

    PubMed Central

    Cautivo, Kelly M.; Molofsky, Ari B.

    2016-01-01

    Adipose tissue (AT) is home to an abundance of immune cells. With chronic obesity, inflammatory immune cells accumulate and promote insulin resistance and the progression to type 2 diabetes mellitus (T2DM). In contrast, recent studies have highlighted the regulation and function of immune cells in lean, healthy adipose tissue, including those associated with type 2 or “allergic” immunity. Although traditionally activated by infection with multicellular helminthes, AT type 2 immunity is active independently of infection, and promotes tissue homeostasis, adipose tissue “browning”, and systemic insulin sensitivity, protecting against obesity-induced metabolic dysfunction and T2DM. In particular, group 2 innate lymphoid cells (ILC2s) are integral regulators of AT type 2 immunity, producing the cytokines IL-5 and IL-13, promoting eosinophils and alternatively activated macrophages, and cooperating with and promoting AT regulatory T (Treg) cells. In this review, we focus on the recent developments in our understanding of ILC2 cells and type 2 immunity in adipose tissue metabolism and homeostasis. PMID:27120716

  20. A Stat6/Pten Axis Links Regulatory T Cells with Adipose Tissue Function.

    PubMed

    Kälin, Stefanie; Becker, Maike; Ott, Verena B; Serr, Isabelle; Hosp, Fabian; Mollah, Mohammad M H; Keipert, Susanne; Lamp, Daniel; Rohner-Jeanrenaud, Francoise; Flynn, Victoria K; Scherm, Martin G; Nascimento, Lucas F R; Gerlach, Katharina; Popp, Vanessa; Dietzen, Sarah; Bopp, Tobias; Krishnamurthy, Purna; Kaplan, Mark H; Serrano, Manuel; Woods, Stephen C; Tripal, Philipp; Palmisano, Ralf; Jastroch, Martin; Blüher, Matthias; Wolfrum, Christian; Weigmann, Benno; Ziegler, Anette-Gabriele; Mann, Matthias; Tschöp, Matthias H; Daniel, Carolin

    2017-09-05

    Obesity and type 2 diabetes are associated with metabolic defects and adipose tissue inflammation. Foxp3(+) regulatory T cells (Tregs) control tissue homeostasis by counteracting local inflammation. However, if and how T cells interlink environmental influences with adipocyte function remains unknown. Here, we report that enhancing sympathetic tone by cold exposure, beta3-adrenergic receptor (ADRB3) stimulation or a short-term high-calorie diet enhances Treg induction in vitro and in vivo. CD4(+) T cell proteomes revealed higher expression of Foxp3 regulatory networks in response to cold or ADRB3 stimulation in vivo reflecting Treg induction. Specifically, Ragulator-interacting protein C17orf59, which limits mTORC1 activity, was upregulated in CD4(+) T cells by either ADRB3 stimulation or cold exposure, suggesting contribution to Treg induction. By loss- and gain-of-function studies, including Treg depletion and transfers in vivo, we demonstrated that a T cell-specific Stat6/Pten axis links cold exposure or ADRB3 stimulation with Foxp3(+) Treg induction and adipose tissue function. Our findings offer a new mechanistic model in which tissue-specific Tregs maintain adipose tissue function. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Adipose tissues and thyroid hormones

    PubMed Central

    Obregon, Maria-Jesus

    2014-01-01

    The maintenance of energy balance is regulated by complex homeostatic mechanisms, including those emanating from adipose tissue. The main function of the adipose tissue is to store the excess of metabolic energy in the form of fat. The energy stored as fat can be mobilized during periods of energy deprivation (hunger, fasting, diseases). The adipose tissue has also a homeostatic role regulating energy balance and functioning as endocrine organ that secretes substances that control body homeostasis. Two adipose tissues have been identified: white and brown adipose tissues (WAT and BAT) with different phenotype, function and regulation. WAT stores energy, while BAT dissipates energy as heat. Brown and white adipocytes have different ontogenetic origin and lineage and specific markers of WAT and BAT have been identified. “Brite” or beige adipose tissue has been identified in WAT with some properties of BAT. Thyroid hormones exert pleiotropic actions, regulating the differentiation process in many tissues including the adipose tissue. Adipogenesis gives raise to mature adipocytes and is regulated by several transcription factors (c/EBPs, PPARs) that coordinately activate specific genes, resulting in the adipocyte phenotype. T3 regulates several genes involved in lipid mobilization and storage and in thermogenesis. Both WAT and BAT are targets of thyroid hormones, which regulate genes crucial for their proper function: lipogenesis, lipolysis, thermogenesis, mitochondrial function, transcription factors, the availability of nutrients. T3 acts directly through specific TREs in the gene promoters, regulating transcription factors. The deiodinases D3, D2, and D1 regulate the availability of T3. D3 is activated during proliferation, while D2 is linked to the adipocyte differentiation program, providing T3 needed for lipogenesis and thermogenesis. We examine the differences between BAT, WAT and brite/beige adipocytes and the process that lead to activation of UCP1 in WAT

  2. Pleiotropic effects of apolipoprotein C3 on HDL functionality and adipose tissue metabolic activity.

    PubMed

    Zvintzou, Evangelia; Lhomme, Marie; Chasapi, Stella; Filou, Serafoula; Theodoropoulos, Vassilis; Xapapadaki, Eva; Kontush, Anatol; Spyroulias, George; Tellis, Constantinos C; Tselepis, Alexandros D; Constantinou, Caterina; Kypreos, Kyriakos E

    2017-09-01

    APOC3 is produced mainly by the liver and intestine and approximately half of plasma APOC3 associates with HDL. Though it was believed that APOC3 associates with HDL by simple binding to preexisting particles, recent data support that biogenesis of APOC3-containing HDL (APOC3-HDL) requires Abca1. Moreover, APOC3-HDL contributes to plasma triglyceride homeostasis by preventing APOC3 association with triglyceride-rich lipoproteins. Interestingly, APOC3-HDL also shows positive correlation with the morbidly obese phenotype. However, the roles of APOC3 in HDL functionality and adipose tissue metabolic activity remain unknown. Therefore, here we investigated the direct effects of APOC3 expression on HDL structure and function, as well as white adipose tissue (WAT) and brown adipose tissue (BAT) metabolic activity. C57BL/6 mice were infected with an adenovirus expressing human APOC3 or a recombinant attenuated control adenovirus expressing green fluorescent protein and blood and tissue samples were collected at 5 days postinfection. HDL was then analyzed for its apolipoprotein and lipid composition and particle functionality. Additionally, purified mitochondria from BAT and WAT were analyzed for uncoupling protein 1, cytochrome c (Cytc), and Cytc oxidase subunit 4 protein levels as an indirect measure of their metabolic activity. Serum metabolomic analysis was performed by NMR. Combined, our data show that APOC3 modulates HDL structure and function, while it selectively promotes BAT metabolic activation. Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.

  3. Pharmacologic activation of estrogen receptor β increases mitochondrial function, energy expenditure, and brown adipose tissue.

    PubMed

    Ponnusamy, Suriyan; Tran, Quynh T; Harvey, Innocence; Smallwood, Heather S; Thiyagarajan, Thirumagal; Banerjee, Souvik; Johnson, Daniel L; Dalton, James T; Sullivan, Ryan D; Miller, Duane D; Bridges, Dave; Narayanan, Ramesh

    2017-01-01

    Most satiety-inducing obesity therapeutics, despite modest efficacy, have safety concerns that underscore the need for effective peripherally acting drugs. An attractive therapeutic approach for obesity is to optimize/maximize energy expenditure by increasing energy-utilizing thermogenic brown adipose tissue. We used in vivo and in vitro models to determine the role of estrogen receptor β (ER-β) and its ligands on adipose biology. RNA sequencing and metabolomics were used to determine the mechanism of action of ER-β and its ligands. Estrogen receptor β (ER-β) and its selective ligand reprogrammed preadipocytes and precursor stem cells into brown adipose tissue and increased mitochondrial respiration. An ER-β-selective ligand increased markers of tricarboxylic acid-dependent and -independent energy biogenesis and oxygen consumption in mice without a concomitant increase in physical activity or food consumption, all culminating in significantly reduced weight gain and adiposity. The antiobesity effects of ER-β ligand were not observed in ER-β-knockout mice. Serum metabolite profiles of adult lean and juvenile mice were comparable, while that of adult obese mice was distinct, indicating a possible impact of obesity on age-dependent metabolism. This phenotype was partially reversed by ER-β-selective ligand. These data highlight a new role for ER-β in adipose biology and its potential to be a safer alternative peripheral therapeutic target for obesity.-Ponnusamy, S., Tran, Q. T., Harvey, I., Smallwood, H. S., Thiyagarajan, T., Banerjee, S., Johnson, D. L., Dalton, J. T., Sullivan, R. D., Miller, D. D., Bridges, D., Narayanan, R. Pharmacologic activation of estrogen receptor β increases mitochondrial function, energy expenditure, and brown adipose tissue. © FASEB.

  4. Eosinophils are key regulators of perivascular adipose tissue and vascular functionality

    PubMed Central

    Withers, Sarah B.; Forman, Ruth; Meza-Perez, Selene; Sorobetea, Daniel; Sitnik, Kasia; Hopwood, Thomas; Lawrence, Catherine B.; Agace, William W.; Else, Kathryn J.; Heagerty, Anthony M.; Svensson-Frej, Marcus; Cruickshank, Sheena M.

    2017-01-01

    Obesity impairs the relaxant capacity of adipose tissue surrounding the vasculature (PVAT) and has been implicated in resultant obesity-related hypertension and impaired glucose intolerance. Resident immune cells are thought to regulate adipocyte activity. We investigated the role of eosinophils in mediating normal PVAT function. Healthy PVAT elicits an anti-contractile effect, which was lost in mice deficient in eosinophils, mimicking the obese phenotype, and was restored upon eosinophil reconstitution. Ex vivo studies demonstrated that the loss of PVAT function was due to reduced bioavailability of adiponectin and adipocyte-derived nitric oxide, which was restored after eosinophil reconstitution. Mechanistic studies demonstrated that adiponectin and nitric oxide are released after activation of adipocyte-expressed β3 adrenoceptors by catecholamines, and identified eosinophils as a novel source of these mediators. We conclude that adipose tissue eosinophils play a key role in the regulation of normal PVAT anti-contractile function. PMID:28303919

  5. Adipose tissue as a dedicated reservoir of functional mast cell progenitors.

    PubMed

    Poglio, Sandrine; De Toni-Costes, Fabienne; Arnaud, Emmanuelle; Laharrague, Patrick; Espinosa, Eric; Casteilla, Louis; Cousin, Béatrice

    2010-11-01

    White adipose tissue (WAT) is a heterogeneous tissue, found in various locations throughout the body, containing mature adipocytes and the stroma-vascular fraction (SVF). The SVF includes a large proportion of immune hematopoietic cells, among which, mast cells that contribute to diet-induced obesity. In this study, we asked whether mast cells present in mice adipose tissue could derive from hematopoietic stem/progenitor cells (HSPC) identified in the tissue. We therefore performed both in vitro and in vivo experiments dedicated to monitoring the progeny of WAT-derived HSPC. The entire study was conducted in parallel with bone marrow-derived cells, considered the gold standard for hematopoietic-lineage studies. Here, we demonstrate that adipose-derived HSPC contain a precursor-cell population committed to the mast cell lineage, and able to efficiently home to peripheral organs such as intestine and skin, where it acquires properties of functional tissue mast cells. Additionally, WAT contains a significant mast cell progenitor population, suggesting that the entire mast cell lineage process take place in WAT. Considering the quantitative importance of WAT in the adult organism and the increasing roles recently assigned to mast cells in physiopathology, WAT may represent an important source of mast cells in physiological and pathological situations. Copyright © 2010 AlphaMed Press.

  6. Diabetic human adipose tissue-derived mesenchymal stem cells fail to differentiate in functional adipocytes.

    PubMed

    Barbagallo, Ignazio; Li Volti, Giovanni; Galvano, Fabio; Tettamanti, Guido; Pluchinotta, Francesca R; Bergante, Sonia; Vanella, Luca

    2016-11-30

    Adipose tissue dysfunction represents a hallmark of diabetic patients and is a consequence of the altered homeostasis of this tissue. Mesenchymal stem cells (MSCs) and their differentiation into adipocytes contribute significantly in maintaining the mass and function of adult adipose tissue. The aim of this study was to evaluate the differentiation of MSCs from patients suffering type 2 diabetes (dASC) and how such process results in hyperplasia or rather a stop of adipocyte turnover resulting in hypertrophy of mature adipocytes. Our results showed that gene profile of all adipogenic markers is not expressed in diabetic cells after differentiation indicating that diabetic cells fail to differentiate into adipocytes. Interestingly, delta like 1, peroxisome proliferator-activated receptor alpha, and interleukin 1β were upregulated whereas Sirtuin 1 and insulin receptor substrate 1 gene expression were found downregulated in dASC compared to cells obtained from healthy subjects. Taken together our data indicate that dASC lose their ability to differentiate into mature and functional adipocytes. In conclusion, our in vitro study is the first to suggest that diabetic patients might develop obesity through a hypertrophy of existing mature adipocytes due to failure turnover of adipose tissue.

  7. Mitochondrial function, fatty acid metabolism, and immune system are relevant features of pig adipose tissue development.

    PubMed

    Vincent, Annie; Louveau, Isabelle; Gondret, Florence; Lebret, Bénédicte; Damon, Marie

    2012-11-15

    The molecular mechanisms underlying the genetic control of fat development in humans and livestock species still require characterization. To gain insights on gene expression patterns associated with genetic propensity for adiposity, we compared subcutaneous adipose tissue (SCAT) transcriptomics profiles from two contrasted pig breeds for body fatness. Samples were obtained from Large White (LW; lean phenotype) and Basque pigs (B; low growth and high fat content) at 35 kg (n = 5 per breed) or 145 kg body weight (n = 10 per breed). Using a custom adipose tissue microarray, we found 271 genes to be differentially expressed between the two breeds at both stages, out of which 123 were highly expressed in LW pigs and 148 genes were highly expressed in B pigs. Functional enrichment analysis based on gene ontology (GO) terms highlighted gene groups corresponding to the mitochondrial energy metabolism in LW pigs, whereas immune response was found significantly enriched in B pigs. Genes associated with lipid metabolism, such as ELOVL6, a gene involved in fatty acid elongation, had a lower expression in B compared with LW pigs. Furthermore, despite enlarged adipocyte diameters and higher plasma leptin concentration, B pigs displayed reduced lipogenic enzyme activities compared with LW pigs at 145 kg. Altogether, our results suggest that the development of adiposity was associated with a progressive worsening of the metabolic status, leading to a low-grade inflammatory state, and may thus be of significant interest for both livestock production and human health.

  8. Impact of Doxorubicin Treatment on the Physiological Functions of White Adipose Tissue

    PubMed Central

    Cruz, Maysa Mariana; Cunha, Roberta D. C.; Alonso-Vale, Maria Isabel; Oyama, Lila Missae; Nascimento, Claudia M. Oller; Pimentel, Gustavo Duarte; dos Santos, Ronaldo V. T.; Lira, Fabio Santos

    2016-01-01

    White adipose tissue (WAT) plays a fundamental role in maintaining energy balance and important endocrine functions. The loss of WAT modifies adipokine secretion and disrupts homeostasis, potentially leading to severe metabolic effects and a reduced quality of life. Doxorubicin is a chemotherapeutic agent used clinically because of its good effectiveness against various types of cancer. However, doxorubicin has deleterious effects in many healthy tissues, including WAT, liver, and skeletal and cardiac muscles. Our objective was to investigate the effects of doxorubicin on white adipocytes through in vivo and in vitro experiments. Doxorubicin reduced the uptake of glucose by retroperitoneal adipocytes and 3T3-L1 cells via the inhibition of AMP-activated protein kinase Thr172 phosphorylation and glucose transporter 4 content. Doxorubicin also reduced the serum level of adiponectin and, to a greater extent, the expression of genes encoding lipogenic (Fas and Acc) and adipogenic factors (Pparg, C/ebpa, and Srebp1c) in retroperitoneal adipose tissue. In addition, doxorubicin inhibited both lipogenesis and lipolysis and reduced the hormone-sensitive lipase and adipose tissue triacylglycerol lipase protein levels. Therefore, our results demonstrate the impact of doxorubicin on WAT. These results are important to understand some side effects observed in patients receiving chemotherapy and should encourage new adjuvant treatments that aim to inhibit these side effects. PMID:27015538

  9. Caveolin-1 Secreted from Adipose Tissues and Adipocytes Functions as an Adipogenesis Enhancer.

    PubMed

    Chang, Chia-Chu; Chen, Chen-Yu; Wen, Hui-Chin; Huang, Chih-Yang; Hung, Ming-Shiu; Lu, Hsi-Chi; Chen, Woan-Ling; Chang, Chung-Ho

    2017-09-25

    Caveolin-1 (Cav-1) is expressed abundantly in adipose tissue and involved in many physiological processes. While Cav-1 has been reported to be secreted in pancreatic acinar cells and LNCaP prostate cancer cells, its secretion from adipose tissue awaits investigation. Cav-1 secretion from 3T3-L1 adipocytes and fat tissues from normal chow diet- and high-fat diet (HFD)-fed mice was measured. Functions and uptake of secreted Cav-1 proteins were assessed by adding Cav-1 back to preadipocytes and LNCaP cells. Cav-1 secretion was evident in adipose tissues and were substantially promoted in HFD-fed mice. Cav-1 was detectable in the conditioned media of 3T3-L1 adipocytes but not preadipocytes. Hypertrophied adipocytes induced by glucose and fatty acids secreted more Cav-1, suggesting that hypertrophied adipocytes were responsible for enhanced Cav-1 secretion in obese mice. Secreted Cav-1 was taken up by preadipocytes and LNCaP cells. 3T3-L1 preadipocytes overexpressing Cav-1 were better differentiated, suggesting that secreted Cav-1 may promote adipogenesis. Hypertrophied 3T3-L1 adipocytes enhanced ERK1/2 activation, and the attenuation of ERK1/2 activity by PD98059 inhibited Cav-1 secretion. Cav-1 is actively secreted from adipocytes as a putative adipogenesis enhancer. Hypertrophied adipocytes secrete Cav-1 via ERK1/2-dependent mechanisms to promote adipogenesis, thus establishing a vicious cycle. © 2017 The Obesity Society.

  10. Impact of Doxorubicin Treatment on the Physiological Functions of White Adipose Tissue.

    PubMed

    Biondo, Luana Amorim; Lima Junior, Edson Alves; Souza, Camila Oliveira; Cruz, Maysa Mariana; Cunha, Roberta D C; Alonso-Vale, Maria Isabel; Oyama, Lila Missae; Nascimento, Claudia M Oller; Pimentel, Gustavo Duarte; Dos Santos, Ronaldo V T; Lira, Fabio Santos; Rosa Neto, José Cesar

    2016-01-01

    White adipose tissue (WAT) plays a fundamental role in maintaining energy balance and important endocrine functions. The loss of WAT modifies adipokine secretion and disrupts homeostasis, potentially leading to severe metabolic effects and a reduced quality of life. Doxorubicin is a chemotherapeutic agent used clinically because of its good effectiveness against various types of cancer. However, doxorubicin has deleterious effects in many healthy tissues, including WAT, liver, and skeletal and cardiac muscles. Our objective was to investigate the effects of doxorubicin on white adipocytes through in vivo and in vitro experiments. Doxorubicin reduced the uptake of glucose by retroperitoneal adipocytes and 3T3-L1 cells via the inhibition of AMP-activated protein kinase Thr172 phosphorylation and glucose transporter 4 content. Doxorubicin also reduced the serum level of adiponectin and, to a greater extent, the expression of genes encoding lipogenic (Fas and Acc) and adipogenic factors (Pparg, C/ebpa, and Srebp1c) in retroperitoneal adipose tissue. In addition, doxorubicin inhibited both lipogenesis and lipolysis and reduced the hormone-sensitive lipase and adipose tissue triacylglycerol lipase protein levels. Therefore, our results demonstrate the impact of doxorubicin on WAT. These results are important to understand some side effects observed in patients receiving chemotherapy and should encourage new adjuvant treatments that aim to inhibit these side effects.

  11. Blockade of the renin-angiotensin system in small arteries and anticontractile function of perivascular adipose tissue.

    PubMed

    Rosei, Claudia Agabiti; Withers, Sarah B; Belcaid, Laila; De Ciuceis, Carolina; Rizzoni, Damiano; Heagerty, Anthony M

    2015-05-01

    In patients with obesity, there is increased inflammation with attendant oxidative stress in perivascular adipose tissue. This has functional consequences with loss of vasodilator adipokine bioavailability. Part of the inflammatory response is mediated by increased activation of the renin-angiotensin-aldosterone axis. Therefore, this study was designed to investigate whether angiotensin-converting enzyme inhibitors or angiotensin receptor blockers can improve the anticontractile function of perivascular adipose tissue. Segments of rat mesenteric small artery were dissected and mounted in a wire myograph and contracted to incremental doses of norepinephrine in the presence and absence of perivascular adipose tissue and in conditions of normal oxygenation or after hypoxia and incubated with captopril or telmisartan. Vessels with perivascular adipose tissue contracted significantly less than arteries with perivascular adipose tissue removed under normal oxygenation conditions, indicating that perivascular adipose tissue exerts an anticontractile effect. Hypoxia induced a loss of this anticontractile effect which could be completely prevented with captopril or telmisartan. The in-vitro creation of a hypoxic environment can simulate the loss of anticontractile perivascular adipose tissue function seen in vivo in obese patients, and this can be prevented using inhibitors of the renin-angiotensin cascade.

  12. Functional changes in adipose tissue in a randomised controlled trial of physical activity

    PubMed Central

    2012-01-01

    Background A sedentary lifestyle predisposes to cardiometabolic diseases. Lifestyle changes such as increased physical activity improve a range of cardiometabolic risk factors. The objective of this study was to examine whether functional changes in adipose tissue were related to these improvements. Methods Seventy-three sedentary, overweight (mean BMI 29.9 ± 3.2 kg/m2) and abdominally obese, but otherwise healthy men and women (67.6 ± 0.5 years) from a randomised controlled trial of physical activity on prescription over a 6-month period were included (control n = 43, intervention n = 30). Detailed examinations were carried out at baseline and at follow-up, including fasting blood samples, a comprehensive questionnaire and subcutaneous adipose tissue biopsies for fatty acid composition analysis (n = 73) and quantification of mRNA expression levels of 13 candidate genes (n = 51), including adiponectin, leptin and inflammatory cytokines. Results At follow-up, the intervention group had a greater increase in exercise time (+137 min/week) and a greater decrease in body fat mass (−1.5 kg) compared to the control subjects (changes of 0 min/week and −0.5 kg respectively). Circulating concentrations of adiponectin were unchanged, but those of leptin decreased significantly more in the intervention group (−1.8 vs −1.1 ng/mL for intervention vs control, P < 0.05). The w6-polyunsaturated fatty acid content, in particular linoleic acid (18:2w6), of adipose tissue increased significantly more in the intervention group, but the magnitude of the change was small (+0.17 vs +0.02 percentage points for intervention vs control, P < 0.05). Surprisingly leptin mRNA levels in adipose tissue increased in the intervention group (+107% intervention vs −20% control, P < 0.05), but changes in expression of the remaining genes did not differ between the groups. Conclusions After a 6-month period of increased physical activity in

  13. Differential Roles of Insulin and IGF-1 Receptors in Adipose Tissue Development and Function

    PubMed Central

    Boucher, Jeremie; Softic, Samir; El Ouaamari, Abdelfattah; Krumpoch, Megan T.; Kleinridders, Andre; Kulkarni, Rohit N.; O’Neill, Brian T.

    2016-01-01

    To determine the roles of insulin and insulin-like growth factor 1 (IGF-1) action in adipose tissue, we created mice lacking the insulin receptor (IR), IGF-1 receptor (IGF1R), or both using Cre-recombinase driven by the adiponectin promoter. Mice lacking IGF1R only (F-IGFRKO) had a ∼25% reduction in white adipose tissue (WAT) and brown adipose tissue (BAT), whereas mice lacking both IR and IGF1R (F-IR/IGFRKO) showed an almost complete absence of WAT and BAT. Interestingly, mice lacking only the IR (F-IRKO) had a 95% reduction in WAT, but a paradoxical 50% increase in BAT with accumulation of large unilocular lipid droplets. Both F-IRKO and F-IR/IGFRKO mice were unable to maintain body temperature in the cold and developed severe diabetes, ectopic lipid accumulation in liver and muscle, and pancreatic islet hyperplasia. Leptin treatment normalized blood glucose levels in both groups. Glucose levels also improved spontaneously by 1 year of age, despite sustained lipodystrophy and insulin resistance. Thus, loss of IR is sufficient to disrupt white fat formation, but not brown fat formation and/or maintenance, although it is required for normal BAT function and temperature homeostasis. IGF1R has only a modest contribution to both WAT and BAT formation and function. PMID:27207537

  14. Development of thermogenic adipose tissue.

    PubMed

    Loncar, D

    1991-09-01

    Besides having a metabolic and insulatory-supporting function, adipose tissue in endotherms also performs a thermogenic function. Thermogenic adipocytes contain specific UC-mitochondria with uncoupling protein (UCP) and produce heat. Thermogenic adipose tissue has two forms: brown adipose tissue (BAT) and convertible adipose tissue (CAT). Brown adipocytes have UC-mitochondria and express UCP throughout the entire life of small rodents, chiropterans, and insectivores. However, in other endotherms and in humans CAT participates as thermogenic tissue only during early postnatal period. Both BAT and CAT start to develop in utero, although in some animals (hamsters, marsupials) or in some particular areas (thoraco-periaortal and medio-perirenal areas in rats) development of thermogenic adipose tissue starts after birth. Postnatal development of BAT in small endotherms is characterized by quantitative changes (the amount of UC-mitochondria, UCP, and lipids). Postnatal development of CAT causes qualitative changes during which UC-mitochondria in convertible adipocytes are replaced by common, nonthermogenic C-mitochondria; vascularization of adipocytes drops to a low level and, with lipid accumulation, convertible adipocytes appear as lipid-store cells. Postnatal development of CAT can be modulated or reversed by the environmental temperature. The duration of postnatal changes varies between species; i.e., cats, rabbits and sheep, change their thermogenic form of CAT into the lipid-store form within the first postnatal month, while in humans the same process takes up to 15-20 years. In maturity all these large endotherms have CAT in lipid-store form. In light of these results, the question of participation of thermogenic adipose tissue in the regulation of human obesity needs to be answered.

  15. The influence of sex steroids on adipose tissue growth and function.

    PubMed

    Law, James; Bloor, Ian; Budge, Helen; Symonds, Michael E

    2014-07-01

    Obesity remains a major global health concern. Understanding the metabolic influences of the obesity epidemic in the human population on maintenance of a healthy weight and metabolic profile is still of great significance. The importance and role of white adipose tissue has been long established, particularly with excess adiposity. Brown adipose tissue (BAT), however, has only recently been shown to contribute significantly to the metabolic signature of mammals outside the previously recognised role in small mammals and neonates. BAT's detection in adults has led to a renewed interest and is now considered to be a potential therapeutic target to prevent excess white fat accumulation in obesity, a theory further promoted by the recent discovery of beige fat. Adipose tissue distribution varies significantly between genders. Pre-menopausal females often show enhanced lower and peripheral fat deposition in adiposity deposition compared to the male profile of central and visceral fat accumulation with obesity. This sex disparity is partly attributed to the different effects of sex hormone profiles and interactions on the adipose tissue system. In this review, we explore this intricate relationship and show how modifications in the effects of sex hormones impact on both brown and white adipose tissues. We also discuss the impact of sex hormones on activation of the hypothalamic-pituitary-adrenal (HPA) axis and how the three pathways between adiposity, HPA and sex steroids can have a major contribution to the prevention or maintenance of obesity and therefore on overall health.

  16. Brown Adipose Tissue Function Is Enhanced in Long-Lived, Male Ames Dwarf Mice.

    PubMed

    Darcy, Justin; McFadden, Samuel; Fang, Yimin; Huber, Joshua A; Zhang, Chi; Sun, Liou Y; Bartke, Andrzej

    2016-12-01

    Ames dwarf mice (Prop1(df/df)) are long-lived due to a loss of function mutation, resulting in deficiency of GH, TSH, and prolactin. Along with a marked extension of longevity, Ames dwarf mice have improved energy metabolism as measured by an increase in their oxygen consumption and heat production, as well as a decrease in their respiratory quotient. Along with alterations in energy metabolism, Ames dwarf mice have a lower core body temperature. Moreover, Ames dwarf mice have functionally altered epididymal white adipose tissue (WAT) that improves, rather than impairs, their insulin sensitivity due to a shift from pro- to anti-inflammatory cytokine secretion. Given the unique phenotype of Ames dwarf epididymal WAT, their improved energy metabolism, and lower core body temperature, we hypothesized that Ames dwarf brown adipose tissue (BAT) may function differently from that of their normal littermates. Here we use histology and RT-PCR to demonstrate that Ames dwarf mice have enhanced BAT function. We also use interscapular BAT removal to demonstrate that BAT is necessary for Ames dwarf energy metabolism and thermogenesis, whereas it is less important for their normal littermates. Furthermore, we show that Ames dwarf mice are able to compensate for loss of interscapular BAT by using their WAT depots as an energy source. These findings demonstrate enhanced BAT function in animals with GH and thyroid hormone deficiencies, chronic reduction of body temperature, and remarkably extended longevity.

  17. Obesity Determines the Immunophenotypic Profile and Functional Characteristics of Human Mesenchymal Stem Cells From Adipose Tissue

    PubMed Central

    Pachón-Peña, Gisela; Serena, Carolina; Ejarque, Miriam; Petriz, Jordi; Duran, Xevi; Oliva-Olivera, W.; Simó, Rafael; Tinahones, Francisco J.

    2016-01-01

    Adipose tissue is a major source of mesenchymal stem cells (MSCs), which possess a variety of properties that make them ideal candidates for regenerative and immunomodulatory therapies. Here, we compared the immunophenotypic profile of human adipose-derived stem cells (hASCs) from lean and obese individuals, and explored its relationship with the apparent altered plasticity of hASCs. We also hypothesized that persistent hypoxia treatment of cultured hASCs may be necessary but not sufficient to drive significant changes in mature adipocytes. hASCs were obtained from subcutaneous adipose tissue of healthy, adult, female donors undergoing abdominal plastic surgery: lean (n = 8; body mass index [BMI]: 23 ± 1 kg/m2) and obese (n = 8; BMI: 35 ± 5 kg/m2). Cell surface marker expression, proliferation and migration capacity, and adipogenic differentiation potential of cultured hASCs at two different oxygen conditions were studied. Compared with lean-derived hASCs, obese-derived hASCs demonstrated increased proliferation and migration capacity but decreased lipid droplet accumulation, correlating with a higher expression of human leukocyte antigen (HLA)-II and cluster of differentiation (CD) 106 and lower expression of CD29. Of interest, adipogenic differentiation modified CD106, CD49b, HLA-ABC surface protein expression, which was dependent on the donor’s BMI. Additionally, low oxygen tension increased proliferation and migration of lean but not obese hASCs, which correlated with an altered CD36 and CD49b immunophenotypic profile. In summary, the differences observed in proliferation, migration, and differentiation capacity in obese hASCs occurred in parallel with changes in cell surface markers, both under basal conditions and during differentiation. Therefore, obesity is an important determinant of stem cell function independent of oxygen tension. Significance The obesity-related hypoxic environment may have latent effects on human adipose tissue-derived mesenchymal

  18. Obesity Determines the Immunophenotypic Profile and Functional Characteristics of Human Mesenchymal Stem Cells From Adipose Tissue.

    PubMed

    Pachón-Peña, Gisela; Serena, Carolina; Ejarque, Miriam; Petriz, Jordi; Duran, Xevi; Oliva-Olivera, W; Simó, Rafael; Tinahones, Francisco J; Fernández-Veledo, Sonia; Vendrell, Joan

    2016-04-01

    Adipose tissue is a major source of mesenchymal stem cells (MSCs), which possess a variety of properties that make them ideal candidates for regenerative and immunomodulatory therapies. Here, we compared the immunophenotypic profile of human adipose-derived stem cells (hASCs) from lean and obese individuals, and explored its relationship with the apparent altered plasticity of hASCs. We also hypothesized that persistent hypoxia treatment of cultured hASCs may be necessary but not sufficient to drive significant changes in mature adipocytes. hASCs were obtained from subcutaneous adipose tissue of healthy, adult, female donors undergoing abdominal plastic surgery: lean (n=8; body mass index [BMI]: 23±1 kg/m2) and obese (n=8; BMI: 35±5 kg/m2). Cell surface marker expression, proliferation and migration capacity, and adipogenic differentiation potential of cultured hASCs at two different oxygen conditions were studied. Compared with lean-derived hASCs, obese-derived hASCs demonstrated increased proliferation and migration capacity but decreased lipid droplet accumulation, correlating with a higher expression of human leukocyte antigen (HLA)-II and cluster of differentiation (CD) 106 and lower expression of CD29. Of interest, adipogenic differentiation modified CD106, CD49b, HLA-ABC surface protein expression, which was dependent on the donor's BMI. Additionally, low oxygen tension increased proliferation and migration of lean but not obese hASCs, which correlated with an altered CD36 and CD49b immunophenotypic profile. In summary, the differences observed in proliferation, migration, and differentiation capacity in obese hASCs occurred in parallel with changes in cell surface markers, both under basal conditions and during differentiation. Therefore, obesity is an important determinant of stem cell function independent of oxygen tension. The obesity-related hypoxic environment may have latent effects on human adipose tissue-derived mesenchymal stem cells (hASCs) with

  19. Adipocytes and adipose tissue.

    PubMed

    Kiess, Wieland; Petzold, Stephanie; Töpfer, Madlen; Garten, Antje; Blüher, Susann; Kapellen, Thomas; Körner, Antje; Kratzsch, Jürgen

    2008-02-01

    An epidemic of obesity is taking place in most societies around the world. Overall obesity substantially increases the risk of subsequent morbidity. In children and adolescents the degree of body fat mass depends upon ethnic background, gender, developmental stage and age. Obesity is characterized by increases in the number or size of fat cells, or a combination of both. It is generally believed that the number of fat cells depends on age of onset and degree of obesity. This chapter provides information on intrauterine growth of fetal adipose tissue, the earliest period of onset of proliferation, and some of the factors that interact to enhance or suppress development. Fetal adipose tissue development is regulated by the complex interaction of transcription factors, nutrients and adipocytokines. Maternal, endocrine, and paracrine factors also influence specific changes in angiogenesis, adipogenesis, and metabolism. During embryogenesis and in fetal life, leptin and adiponectin, two important adipocytokines, are present at high concentrations in the circulation and in tissues. Developmental stages and metabolic processes influenced by specific hormones and paracrine factors have been identified through examination of the offspring of obese and diabetic pregnancies, hormonal manipulation during late pregnancy in animal models, and the use of cell cultures. Collectively, the results of the studies cited herein delineate the basis for imprinting or conditioning of fetal pre-adipocytes at the paracrine/autocrine level, and of fetal adipose tissue development and metabolism.

  20. Perivascular adipose tissue in vascular function and disease: a review of current research and animal models.

    PubMed

    Brown, Nicholas K; Zhou, Zhou; Zhang, Jifeng; Zeng, Rong; Wu, Jiarui; Eitzman, Daniel T; Chen, Y Eugene; Chang, Lin

    2014-08-01

    Perivascular adipose tissue (PVAT), long assumed to be nothing more than vessel-supporting connective tissue, is now understood to be an important, active component of the vasculature, with integral roles in vascular health and disease. PVAT is an adipose tissue with similarities to both brown and white adipose tissue, although recent evidence suggests that PVAT develops from its own precursors. Like other adipose tissue depots, PVAT secretes numerous biologically active substances that can act in both autocrine and paracrine fashion. PVAT has also proven to be involved in vascular inflammation. Although PVAT can support inflammation during atherosclerosis via macrophage accumulation, emerging evidence suggests that PVAT also has antiatherosclerotic properties related to its abilities to induce nonshivering thermogenesis and metabolize fatty acids. We here discuss the accumulated knowledge of PVAT biology and related research on models of hypertension and atherosclerosis.

  1. Differential Roles of Insulin and IGF-1 Receptors in Adipose Tissue Development and Function.

    PubMed

    Boucher, Jeremie; Softic, Samir; El Ouaamari, Abdelfattah; Krumpoch, Megan T; Kleinridders, Andre; Kulkarni, Rohit N; O'Neill, Brian T; Kahn, C Ronald

    2016-08-01

    To determine the roles of insulin and insulin-like growth factor 1 (IGF-1) action in adipose tissue, we created mice lacking the insulin receptor (IR), IGF-1 receptor (IGF1R), or both using Cre-recombinase driven by the adiponectin promoter. Mice lacking IGF1R only (F-IGFRKO) had a ∼25% reduction in white adipose tissue (WAT) and brown adipose tissue (BAT), whereas mice lacking both IR and IGF1R (F-IR/IGFRKO) showed an almost complete absence of WAT and BAT. Interestingly, mice lacking only the IR (F-IRKO) had a 95% reduction in WAT, but a paradoxical 50% increase in BAT with accumulation of large unilocular lipid droplets. Both F-IRKO and F-IR/IGFRKO mice were unable to maintain body temperature in the cold and developed severe diabetes, ectopic lipid accumulation in liver and muscle, and pancreatic islet hyperplasia. Leptin treatment normalized blood glucose levels in both groups. Glucose levels also improved spontaneously by 1 year of age, despite sustained lipodystrophy and insulin resistance. Thus, loss of IR is sufficient to disrupt white fat formation, but not brown fat formation and/or maintenance, although it is required for normal BAT function and temperature homeostasis. IGF1R has only a modest contribution to both WAT and BAT formation and function. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  2. Characterization of adipose-derived stem cells from subcutaneous and visceral adipose tissues and their function in breast cancer cells

    PubMed Central

    Ritter, Andreas; Friemel, Alexandra; Fornoff, Friderike; Adjan, Mouhib; Solbach, Christine

    2015-01-01

    Adipose-derived stem cells are capable of differentiating into multiple cell types and thus considered useful for regenerative medicine. However, this differentiation feature seems to be associated with tumor initiation and metastasis raising safety concerns, which requires further investigation. In this study, we isolated adipose-derived stem cells from subcutaneous as well as from visceral adipose tissues of the same donor and systematically compared their features. Although being characteristic of mesenchymal stem cells, subcutaneous adipose-derived stem cells tend to be spindle form-like and are more able to home to cancer cells, whereas visceral adipose-derived stem cells incline to be “epithelial”-like and more competent to differentiate. Moreover, compared to subcutaneous adipose-derived stem cells, visceral adipose-derived stem cells are more capable of promoting proliferation, inducing the epithelial-to-mesenchymal transition, enhancing migration and invasion of breast cancer cells by cell-cell contact and by secreting interleukins such as IL-6 and IL-8. Importantly, ASCs affect the low malignant breast cancer cells MCF-7 more than the highly metastatic MDA-MB-231 cells. Induction of the epithelial-to-mesenchymal transition is mediated by the activation of multiple pathways especially the PI3K/AKT signaling in breast cancer cells. BCL6, an important player in B-cell lymphoma and breast cancer progression, is crucial for this transition. Finally, this transition fuels malignant properties of breast cancer cells and render them resistant to ATP competitive Polo-like kinase 1 inhibitors BI 2535 and BI 6727. PMID:26439686

  3. Characterization of adipose-derived stem cells from subcutaneous and visceral adipose tissues and their function in breast cancer cells.

    PubMed

    Ritter, Andreas; Friemel, Alexandra; Fornoff, Friderike; Adjan, Mouhib; Solbach, Christine; Yuan, Juping; Louwen, Frank

    2015-10-27

    Adipose-derived stem cells are capable of differentiating into multiple cell types and thus considered useful for regenerative medicine. However, this differentiation feature seems to be associated with tumor initiation and metastasis raising safety concerns, which requires further investigation. In this study, we isolated adipose-derived stem cells from subcutaneous as well as from visceral adipose tissues of the same donor and systematically compared their features. Although being characteristic of mesenchymal stem cells, subcutaneous adipose-derived stem cells tend to be spindle form-like and are more able to home to cancer cells, whereas visceral adipose-derived stem cells incline to be "epithelial"-like and more competent to differentiate. Moreover, compared to subcutaneous adipose-derived stem cells, visceral adipose-derived stem cells are more capable of promoting proliferation, inducing the epithelial-to-mesenchymal transition, enhancing migration and invasion of breast cancer cells by cell-cell contact and by secreting interleukins such as IL-6 and IL-8. Importantly, ASCs affect the low malignant breast cancer cells MCF-7 more than the highly metastatic MDA-MB-231 cells. Induction of the epithelial-to-mesenchymal transition is mediated by the activation of multiple pathways especially the PI3K/AKT signaling in breast cancer cells. BCL6, an important player in B-cell lymphoma and breast cancer progression, is crucial for this transition. Finally, this transition fuels malignant properties of breast cancer cells and render them resistant to ATP competitive Polo-like kinase 1 inhibitors BI 2535 and BI 6727.

  4. Adipose-Derived Stem Cells in Functional Bone Tissue Engineering: Lessons from Bone Mechanobiology

    PubMed Central

    Bodle, Josephine C.; Hanson, Ariel D.

    2011-01-01

    This review aims to highlight the current and significant work in the use of adipose-derived stem cells (ASC) in functional bone tissue engineering framed through the bone mechanobiology perspective. Over a century of work on the principles of bone mechanosensitivity is now being applied to our understanding of bone development. We are just beginning to harness that potential using stem cells in bone tissue engineering. ASC are the primary focus of this review due to their abundance and relative ease of accessibility for autologous procedures. This article outlines the current knowledge base in bone mechanobiology to investigate how the knowledge from this area has been applied to the various stem cell-based approaches to engineering bone tissue constructs. Specific emphasis is placed on the use of human ASC for this application. PMID:21338267

  5. Trypanosoma brucei parasites occupy and functionally adapt to the adipose tissue in mice

    DOE PAGES

    Trindade, Sandra; Rijo-Ferreira, Filipa; Carvalho, Tania; ...

    2016-05-26

    Trypanosoma brucei is an extracellular parasite that causes sleeping sickness. In mammalian hosts, trypanosomes are thought to exist in two major niches: early in infection, they populate the blood; later, they breach the blood-brain barrier. Working with a well-established mouse model, we discovered that adipose tissue constitutes a third major reservoir for T. brucei. Parasites from adipose tissue, here termed adipose tissue forms (ATFs), can replicate and were capable of infecting a naive animal. ATFs were transcriptionally distinct from bloodstream forms, and the genes upregulated included putative fatty acid β-oxidation enzymes. Consistent with this, ATFs were able to utilize exogenousmore » myristate and form β-oxidation intermediates, suggesting that ATF parasites can use fatty acids as an external carbon source. Lastly, these findings identify the adipose tissue as a niche for T. brucei during its mammalian life cycle and could potentially explain the weight loss associated with sleeping sickness.« less

  6. Renin dynamics in adipose tissue: adipose tissue control of local renin concentrations.

    PubMed

    Fowler, Jason D; Krueth, Stacy B; Bernlohr, David A; Katz, Stephen A

    2009-02-01

    The renin-angiotensin system (RAS) has been implicated in a variety of adipose tissue functions, including tissue growth, differentiation, metabolism, and inflammation. Although expression of all components necessary for a locally derived adipose tissue RAS has been demonstrated within adipose tissue, independence of local adipose RAS component concentrations from corresponding plasma RAS fluctuations has not been addressed. To analyze this, we varied in vivo rat plasma concentrations of two RAS components, renin and angiotensinogen (AGT), to determine the influence of their plasma concentrations on adipose and cardiac tissue levels in both perfused (plasma removed) and nonperfused samples. Variation of plasma RAS components was accomplished by four treatment groups: normal, DOCA salt, bilateral nephrectomy, and losartan. Adipose and cardiac tissue AGT concentrations correlated positively with plasma values. Perfusion of adipose tissue decreased AGT concentrations by 11.1%, indicating that adipose tissue AGT was in equilibrium with plasma. Cardiac tissue renin levels positively correlated with plasma renin concentration for all treatments. In contrast, adipose tissue renin levels did not correlate with plasma renin, with the exception of extremely high plasma renin concentrations achieved in the losartan-treated group. These results suggest that adipose tissue may control its own local renin concentration independently of plasma renin as a potential mechanism for maintaining a functional local adipose RAS.

  7. Triglyceride depletion of brown adipose tissue enables analysis of mitochondrial respiratory function in permeabilized biopsies.

    PubMed

    Dechandt, Carlos R P; Couto-Lima, Carlos A; Alberici, Luciane C

    2016-12-15

    The research on mitochondrial functions in adipocytes has increasingly evidenced that mitochondria plays an important role in the onset and/or progression of obesity and related pathologies. Mitochondrial function in brown adipose tissue (BAT) has been classically assessed by measuring either the levels/activity of mitochondrial enzymes, or the respiration in isolated mitochondria. Isolation of mitochondria is not advantageous because it demands significant time and amount of tissue and, as tissue homogenates, disrupts biochemical and physical connections of mitochondria within the cell. Here, we described a new and efficient protocol to analyze the mitochondrial respiratory states in BAT biopsies that relies on intracellular triglyceride depletion followed by tissue permeabilization. In addition to minimizing tissue requirements to ∼17 mg wet weight, the proposed protocol enabled analysis of all mitochondrial respiratory states, including phosphorylation (OXPHOS), no-phosphorylation (LEAK), and uncoupled (ETS) states, as well as the use of substrates for complex I, complex II, and cytochrome c; together, these features demonstrated mitochondrial integrity and validated the preparation efficacy. Therefore, the protocol described here increases the possibilities of answering physiological questions related to small BAT regions of human and animal models, which shall help to unravel the mechanisms that regulate mitochondrial function in health and disease.

  8. Effects of DHEA on metabolic and endocrine functions of adipose tissue.

    PubMed

    Karbowska, Joanna; Kochan, Zdzislaw

    2013-08-01

    Dehydroepiandrosterone (DHEA) and its sulfate ester, DHEAS, are the major circulating adrenal steroids and serve as substrates for sex hormone biosynthesis. DHEA is effectively taken up by adipose tissue, where the concentrations of free DHEA are four to ten times higher than those found in the circulation. DHEA reduces adipose tissue mass and inhibits the proliferation and differentiation of adipocytes; it may also protect against obesity by lowering the activity of stearoyl-CoA desaturase 1 in fat cells. Recent studies demonstrate that DHEA stimulates triacylglycerol hydrolysis in adipose tissue by increasing the expression and activity of adipose triglyceride lipase and hormone-sensitive lipase, the key enzymes of lipolysis. DHEA has been shown to modulate insulin signaling pathways, enhance glucose uptake in adipocytes, and increase insulin sensitivity in patients with DHEA deficiency or abnormal glucose tolerance. Additionally, by suppressing the activity of 11β-hydroxysteroid dehydrogenase 1 in adipocytes, DHEA may promote intra-adipose inactivation of cortisol to cortisone. Several studies have demonstrated that DHEA may also regulate the expression and secretion of adipokines such as leptin, adiponectin, and resistin. The effects of DHEA on adipokine expression in adipose tissue are depot-specific, with visceral fat being the most responsive. The mechanisms underlying DHEA actions in adipose tissue are still unclear; however, they involve nuclear receptors such as androgen receptor and peroxisome proliferator-activated receptors γ and α. Because clinical trials investigating the effects of DHEA failed to yield consistent results, further studies are needed to clarify the role of DHEA in the regulation of human adipose tissue physiology.

  9. Excess Visceral Adipose Tissue Worsens the Vascular Endothelial Function in Patients with Type 2 Diabetes Mellitus

    PubMed Central

    Kurozumi, Akira; Okada, Yosuke; Arao, Tadashi; Tanaka, Yoshiya

    2016-01-01

    Objective Visceral fat obesity and metabolic syndrome correlate with atherosclerosis in part due to insulin resistance and various other factors. The aim of this study was to determine the relationship between vascular endothelial dysfunction and excess visceral adipose tissue (VAT) in Japanese patients with type 2 diabetes mellitus (T2DM). Methods In 71 T2DM patients, the reactive hyperemia index (RHI) was measured using an Endo-PAT 2000, and VAT and subcutaneous adipose tissue (SAT) were measured via CT. We also measured various metabolic markers, including high-molecular-weight adiponectin (HMW-AN). Results VAT correlated negatively with the natural logarithm of RHI (L_RHI), the primary endpoint (p=0.042, r=-0.242). L_RHI did not correlate with SAT, VAT/SAT, abdominal circumference, homeostasis model assessment for insulin resistance, urinary C-peptide reactivity, HMW-AN, or alanine amino transferase, the secondary endpoints. A linear multivariate analysis via the forced entry method using age, sex, VAT, and smoking history as independent variables and L_RHI as the dependent variable revealed a lack of any determinants of L_RHI. Conclusion Excess VAT worsens the vascular endothelial function, represented by RHI which was analyzed using Endo-PAT, in Japanese patients with T2DM. PMID:27803400

  10. Effects of Moderate and Subsequent Progressive Weight Loss on Metabolic Function and Adipose Tissue Biology in Humans with Obesity.

    PubMed

    Magkos, Faidon; Fraterrigo, Gemma; Yoshino, Jun; Luecking, Courtney; Kirbach, Kyleigh; Kelly, Shannon C; de Las Fuentes, Lisa; He, Songbing; Okunade, Adewole L; Patterson, Bruce W; Klein, Samuel

    2016-04-12

    Although 5%-10% weight loss is routinely recommended for people with obesity, the precise effects of 5% and further weight loss on metabolic health are unclear. We conducted a randomized controlled trial that evaluated the effects of 5.1% ± 0.9% (n = 19), 10.8% ± 1.3% (n = 9), and 16.4% ± 2.1% (n = 9) weight loss and weight maintenance (n = 14) on metabolic outcomes. 5% weight loss improved adipose tissue, liver and muscle insulin sensitivity, and β cell function, without a concomitant change in systemic or subcutaneous adipose tissue markers of inflammation. Additional weight loss further improved β cell function and insulin sensitivity in muscle and caused stepwise changes in adipose tissue mass, intrahepatic triglyceride content, and adipose tissue expression of genes involved in cholesterol flux, lipid synthesis, extracellular matrix remodeling, and oxidative stress. These results demonstrate that moderate 5% weight loss improves metabolic function in multiple organs simultaneously, and progressive weight loss causes dose-dependent alterations in key adipose tissue biological pathways. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Targeting adipose tissue via systemic gene therapy.

    PubMed

    O'Neill, S M; Hinkle, C; Chen, S-J; Sandhu, A; Hovhannisyan, R; Stephan, S; Lagor, W R; Ahima, R S; Johnston, J C; Reilly, M P

    2014-07-01

    Adipose tissue has a critical role in energy and metabolic homeostasis, but it is challenging to adapt techniques to modulate adipose function in vivo. Here we develop an in vivo, systemic method of gene transfer specifically targeting adipose tissue using adeno-associated virus (AAV) vectors. We constructed AAV vectors containing cytomegalovirus promoter-regulated reporter genes, intravenously injected adult mice with vectors using multiple AAV serotypes, and determined that AAV2/8 best targeted adipose tissue. Altering vectors to contain adiponectin promoter/enhancer elements and liver-specific microRNA-122 target sites restricted reporter gene expression to adipose tissue. As proof of efficacy, the leptin gene was incorporated into the adipose-targeted expression vector, package into AAV2/8 and administered intravenously to 9- to 10-week-old ob/ob mice. Phenotypic changes were measured over an 8-week period. Leptin mRNA and protein were expressed in adipose and leptin protein was secreted into plasma. Mice responded with reversal of weight gain, decreased hyperinsulinemia and improved glucose tolerance. AAV2/8-mediated systemic delivery of an adipose-targeted expression vector can replace a gene lacking in adipose tissue and correct a mouse model of human disease, demonstrating experimental application and therapeutic potential in disorders of adipose.

  12. Impact of simulated microgravity and caloric restriction on autonomic nervous system function in adipose tissue

    NASA Astrophysics Data System (ADS)

    Boschmann, Michael; Adams, Frauke; Tank, Jens; Schaller, Karin; Boese, Andrea; Heer, Martina; Klause, Susanne; Luft, Friedrich C.; Jordan, Jens

    2005-08-01

    Long term immobilization and reduced food intake is often associated with development of orthostatic intolerance. Blocking the norepinephrine transporter (NET) can also mimic symptoms of orthostatic intolerance. Therefore, we hypothesized that simulated microgravity (14 days bed rest at head down tilt, BR) can cause changes in postganglionic NET function and adrenoreceptor (AR) sensitivity and these changes can be aggravated by hypocaloric food intake. For testing, two microdialysis probes were inserted into subcutaneous adipose tissue of eight young healthy men at day 1 and 14 of BR and perfused with Ringer's solution and increasing doses of tyramine and isoproterenol in order to simulate NET blockade and stimulate AR, respectively. At day 14 of eucaloric diet and BR, isoproterenol induced lipolysis was greater, whereas at day 14 of hypocaloric diet and BR, tyramine induced lipolysis was greater when compared to day 1. Therefore, the nutritional state affects NET function and AR sensitivity differently during BR.

  13. Imaging White Adipose Tissue With Confocal Microscopy

    PubMed Central

    Martinez-Santibañez, Gabriel; Cho, Kae Won; Lumeng, Carey N.

    2014-01-01

    Adipose tissue is composed of a variety of cell types that include mature adipocytes, endothelial cells, fibroblasts, adipocyte progenitors, and a range of inflammatory leukocytes. These cells work in concert to promote nutrient storage in adipose tissue depots and vary widely based on location. In addition, overnutrition and obesity impart significant changes in the architecture of adipose tissue that are strongly associated with metabolic dysfunction. Recent studies have called attention to the importance of adipose tissue microenvironments in regulating adipocyte function and therefore require techniques that preserve cellular interactions and permit detailed analysis of three-dimensional structures in fat. This chapter summarizes our experience with the use of laser scanning confocal microscopy for imaging adipose tissue in rodents. PMID:24480339

  14. Imaging white adipose tissue with confocal microscopy.

    PubMed

    Martinez-Santibañez, Gabriel; Cho, Kae Won; Lumeng, Carey N

    2014-01-01

    Adipose tissue is composed of a variety of cell types that include mature adipocytes, endothelial cells, fibroblasts, adipocyte progenitors, and a range of inflammatory leukocytes. These cells work in concert to promote nutrient storage in adipose tissue depots and vary widely based on location. In addition, overnutrition and obesity impart significant changes in the architecture of adipose tissue that are strongly associated with metabolic dysfunction. Recent studies have called attention to the importance of adipose tissue microenvironments in regulating adipocyte function and therefore require techniques that preserve cellular interactions and permit detailed analysis of three-dimensional structures in fat. This chapter summarizes our experience with the use of laser scanning confocal microscopy for imaging adipose tissue in rodents. © 2014 Elsevier Inc. All rights reserved.

  15. Brown adipose tissue and thermogenesis.

    PubMed

    Fenzl, Anna; Kiefer, Florian W

    2014-07-01

    The growing understanding of adipose tissue as an important endocrine organ with multiple metabolic functions has directed the attention to the (patho)physiology of distinct fat depots. Brown adipose tissue (BAT), in contrast to bona fide white fat, can dissipate significant amounts of chemical energy through uncoupled respiration and heat production (thermogenesis). This process is mediated by the major thermogenic factor uncoupling protein-1 and can be activated by certain stimuli, such as cold exposure, adrenergic compounds or genetic alterations. White adipose tissue (WAT) depots, however, also possess the capacity to acquire brown fat characteristics in response to thermogenic stimuli. The induction of a BAT-like cellular and molecular program in WAT has recently been termed "browning" or "beiging". Promotion of BAT activity or the browning of WAT is associated with in vivo cold tolerance, increased energy expenditure, and protection against obesity and type 2 diabetes. These preclinical observations have gained additional significance with the recent discovery that active BAT is present in adult humans and can be detected by 18fluor-deoxy-glucose positron emission tomography coupled with computed tomography. As in rodents, human BAT can be activated by cold exposure and is associated with increased energy turnover and lower body fat mass. Despite the tremendous progress in brown fat research in recent years, pharmacological concepts to harness BAT function therapeutically are currently still lacking.

  16. SIRT1 enhances glucose tolerance by potentiating brown adipose tissue function

    PubMed Central

    Boutant, Marie; Joffraud, Magali; Kulkarni, Sameer S.; García-Casarrubios, Ester; García-Roves, Pablo M.; Ratajczak, Joanna; Fernández-Marcos, Pablo J.; Valverde, Angela M.; Serrano, Manuel; Cantó, Carles

    2014-01-01

    Objective SIRT1 has been proposed to be a key signaling node linking changes in energy metabolism to transcriptional adaptations. Although SIRT1 overexpression is protective against diverse metabolic complications, especially in response to high-fat diets, studies aiming to understand the etiology of such benefits are scarce. Here, we aimed to identify the key tissues and mechanisms implicated in the beneficial effects of SIRT1 on glucose homeostasis. Methods We have used a mouse model of moderate SIRT1 overexpression, under the control of its natural promoter, to evaluate glucose homeostasis and thoroughly characterize how different tissues could influence insulin sensitivity. Results Mice with moderate overexpression of SIRT1 exhibit better glucose tolerance and insulin sensitivity even on a low fat diet. Euglycemic-hyperinsulinemic clamps and in-depth tissue analyses revealed that enhanced insulin sensitivity was achieved through a higher brown adipose tissue activity and was fully reversed by housing the mice at thermoneutrality. SIRT1 did not influence brown adipocyte differentiation, but dramatically enhanced the metabolic transcriptional responses to β3-adrenergic stimuli in differentiated adipocytes. Conclusions Our work demonstrates that SIRT1 improves glucose homeostasis by enhancing BAT function. This is not consequent to an alteration in the brown adipocyte differentiation process, but as a result of potentiating the response to β3-adrenergic stimuli. PMID:25685699

  17. The microenvironment of visceral adipose tissue and liver alter natural killer cell viability and function.

    PubMed

    Conroy, Melissa J; Fitzgerald, Vivienne; Doyle, Suzanne L; Channon, Shauna; Useckaite, Zivile; Gilmartin, Niamh; O'Farrelly, Cliona; Ravi, Narayanasamy; Reynolds, John V; Lysaght, Joanne

    2016-12-01

    The role of NK cells in visceral adipose tissue (VAT) and liver inflammation in obesity is not fully understood. This study investigated the frequency, cytokine expression, chemokine receptor, and cytotoxicity receptor profile of NK cells in the blood, omentum, and liver of patients with the obesity-associated cancer, oesophageal adenocarcinoma (OAC). The effect of chronically inflamed tissue microenvironments on NK cell viability and function was also examined. We identified significantly lower NK cell frequencies in the liver of OAC patients compared with healthy controls and within the omentum and liver of OAC patients compared with blood, whereas IL-10-producing populations were significantly higher. Interestingly, our data suggest that reduced frequencies of NK cells in omentum and liver of OAC patients are not a result of impaired NK cell chemotaxis to these tissues. In fact, our functional data revealed that secreted factors from omentum and liver of OAC patients induce significant levels of NK cell death and lead to reduced percentages of TNF-α(+) and NKP46(+) NK cells and higher frequencies of IL-10-producing NK cells. Together, these data suggest that the omental and hepatic microenvironments of OAC patients alter the NK cell phenotype to a more anti-inflammatory homeostatic role. © Society for Leukocyte Biology.

  18. White adipose tissue genome wide-expression profiling and adipocyte metabolic functions after soy protein consumption in rats.

    PubMed

    Frigolet, Maria E; Torres, Nimbe; Uribe-Figueroa, Laura; Rangel, Claudia; Jimenez-Sanchez, Gerardo; Tovar, Armando R

    2011-02-01

    Obesity is associated with an increase in adipose tissue mass due to an imbalance between high dietary energy intake and low physical activity; however, the type of dietary protein may contribute to its development. The aim of the present work was to study the effect of soy protein versus casein on white adipose tissue genome profiling, and the metabolic functions of adipocytes in rats with diet-induced obesity. The results showed that rats fed a Soy Protein High-Fat (Soy HF) diet gained less weight and had lower serum leptin concentration than rats fed a Casein High-Fat (Cas HF) diet, despite similar energy intake. Histological studies indicated that rats fed the Soy HF diet had significantly smaller adipocytes than those fed the Cas HF diet, and this was associated with a lower triglyceride/DNA content. Fatty acid synthesis in isolated adipocytes was reduced by the amount of fat consumed but not by the type of protein ingested. Expression of genes of fatty acid oxidation increased in adipose tissue of rats fed Soy diets; microarray analysis revealed that Soy protein consumption modified the expression of 90 genes involved in metabolic functions and inflammatory response in adipose tissue. Network analysis showed that the expression of leptin was regulated by the type of dietary protein and it was identified as a central regulator of the expression of lipid metabolism genes in adipose tissue. Thus, soy maintains the size and metabolic functions of adipose tissue through biochemical adaptations, adipokine secretion, and global changes in gene expression.

  19. MicroRNA-181b Improves Glucose Homeostasis and Insulin Sensitivity by Regulating Endothelial Function in White Adipose Tissue.

    PubMed

    Sun, Xinghui; Lin, Jibin; Zhang, Yu; Kang, Sona; Belkin, Nathan; Wara, Akm K; Icli, Basak; Hamburg, Naomi M; Li, Dazhu; Feinberg, Mark W

    2016-03-04

    The pathogenesis of insulin resistance involves dysregulated gene expression and function in multiple cell types, including endothelial cells (ECs). Post-transcriptional mechanisms such as microRNA-mediated regulation of gene expression could affect insulin action by modulating EC function. To determine whether microRNA-181b (miR-181b) affects the pathogenesis of insulin resistance by regulating EC function in white adipose tissue during obesity. MiR-181b expression was reduced in adipose tissue ECs of obese mice, and rescue of miR-181b expression improved glucose homeostasis and insulin sensitivity. Systemic intravenous delivery of miR-181b robustly accumulated in adipose tissue ECs, enhanced insulin-mediated Akt phosphorylation at Ser473, and reduced endothelial dysfunction, an effect that shifted macrophage polarization toward an M2 anti-inflammatory phenotype in epididymal white adipose tissue. These effects were associated with increased endothelial nitric oxide synthase and FoxO1 phosphorylation as well as nitric oxide activity in epididymal white adipose tissue. In contrast, miR-181b did not affect insulin-stimulated Akt phosphorylation in liver and skeletal muscle. Bioinformatics and gene profiling approaches revealed that Pleckstrin homology domain leucine-rich repeat protein phosphatase, a phosphatase that dephosphorylates Akt at Ser473, is a novel target of miR-181b. Knockdown of Pleckstrin homology domain leucine-rich repeat protein phosphatase increased Akt phosphorylation at Ser473 in ECs, and phenocopied miR-181b's effects on glucose homeostasis, insulin sensitivity, and inflammation of epididymal white adipose tissue in vivo. Finally, ECs from diabetic subjects exhibited increased Pleckstrin homology domain leucine-rich repeat protein phosphatase expression. Our data underscore the importance of adipose tissue EC function in controlling the development of insulin resistance. Delivery of miR-181b or Pleckstrin homology domain leucine-rich repeat

  20. Dependence of Brown Adipose Tissue Function on CD36-Mediated Coenzyme Q Uptake

    PubMed Central

    Anderson, Courtney M.; Kazantzis, Melissa; Wang, Jinshan; Venkatraman, Subramaniam; Goncalves, Renata L. S.; Quinlan, Casey L.; Ng, Ryan; Jastroch, Martin; Benjamin, Daniel I.; Nie, Biao; Herber, Candice; Ngoc Van, An-Angela; Park, Michael J.; Yun, Dawee; Chan, Karen; Yu, Angela; Vuong, Peter; Febbraio, Maria; Nomura, Daniel; Napoli, Joseph; Brand, Martin D.; Stahl, Andreas

    2014-01-01

    Summary Brown adipose tissue (BAT) possesses the inherent ability to dissipate metabolic energy as heat through uncoupled mitochondrial respiration. An essential component of the mitochondrial electron transport chain is coenzyme Q (CoQ). While cells mostly synthesize CoQ endogenously, exogenous supplementation with CoQ has been successful as a therapy for patients with CoQ deficiency. However, which tissues depend on exogenous CoQ uptake as well as the mechanism by which CoQ is taken up by cells and the role of this process in BAT function is not well understood. Here we report that the scavenger receptor CD36 drives the uptake of CoQ by BAT and is required for normal BAT function. BAT from mice lacking CD36 displays CoQ deficiency, impaired CoQ uptake, hypertrophy, altered lipid metabolism, mitochondrial dysfunction, and defective non-shivering thermogenesis. Together, these data reveal an important new role for the systemic transport of CoQ to BAT and its function in thermogenesis. PMID:25620701

  1. An insight into the key genes and biological functions associated with insulin resistance in adipose tissue with microarray technology.

    PubMed

    Zhang, Li; Cui, Ying; Fu, Fangming; Li, Zhenzuo; Pan, Xiaoxia; Li, Hongzhuan; Li, Lin

    2015-03-01

    In the present study, the key genes and biological functions associated with insulin resistance were investigated by comparing the gene expression profiles of adipose tissue obtained from insulin‑sensitive and insulin‑resistant patients. The gene expression data set GSE20950 was downloaded from the Gene Expression Omnibus, including 39 adipose tissue samples obtained from insulin‑sensitive and insulin‑resistant patients undergoing gastric bypass surgery. Adipose samples were divided into two groups (the insulin‑sensitive and insulin‑resistant groups) and the differentially expressed genes (DEGs) were screened out with packages of R. The interactions among DEGs were retrieved with Osprey and functional enrichment analysis was performed with the WebGestalt system. Information regarding the interaction network and enriched biological functions was combined to construct a functional interaction network. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was then conducted using the Database for Annotation, Visualization and Integrated Discovery. A total of 170 DEGs were detected in the insulin‑sensitive group, 8 downregulated and 162 upregulated. Response to glucose stimulus was the most significantly over‑represented functional term. The focal adhesion pathway was identified to be significant in the genes of the functional interaction network. The present study revealed key biological functions and DEGs in adipose tissues associated with insulin resistance, which may facilitate the development of novel therapies for insulin resistance and diabetes.

  2. Adipose Tissue Inflammation Induces B Cell Inflammation and Decreases B Cell Function in Aging

    PubMed Central

    Frasca, Daniela; Blomberg, Bonnie B.

    2017-01-01

    Aging is the greatest risk factor for developing chronic diseases. Inflamm-aging, the age-related increase in low-grade chronic inflammation, may be a common link in age-related diseases. This review summarizes recent published data on potential cellular and molecular mechanisms of the age-related increase in inflammation, and how these contribute to decreased humoral immune responses in aged mice and humans. Briefly, we cover how aging and related inflammation decrease antibody responses in mice and humans, and how obesity contributes to the mechanisms for aging through increased inflammation. We also report data in the literature showing adipose tissue infiltration with immune cells and how these cells are recruited and contribute to local and systemic inflammation. We show that several types of immune cells infiltrate the adipose tissue and these include macrophages, neutrophils, NK cells, innate lymphoid cells, eosinophils, T cells, B1, and B2 cells. Our main focus is how the adipose tissue affects immune responses, in particular B cell responses and antibody production. The role of leptin in generating inflammation and decreased B cell responses is also discussed. We report data published by us and by other groups showing that the adipose tissue generates pro-inflammatory B cell subsets which induce pro-inflammatory T cells, promote insulin resistance, and secrete pathogenic autoimmune antibodies.

  3. Adipose Tissue Inflammation Induces B Cell Inflammation and Decreases B Cell Function in Aging.

    PubMed

    Frasca, Daniela; Blomberg, Bonnie B

    2017-01-01

    Aging is the greatest risk factor for developing chronic diseases. Inflamm-aging, the age-related increase in low-grade chronic inflammation, may be a common link in age-related diseases. This review summarizes recent published data on potential cellular and molecular mechanisms of the age-related increase in inflammation, and how these contribute to decreased humoral immune responses in aged mice and humans. Briefly, we cover how aging and related inflammation decrease antibody responses in mice and humans, and how obesity contributes to the mechanisms for aging through increased inflammation. We also report data in the literature showing adipose tissue infiltration with immune cells and how these cells are recruited and contribute to local and systemic inflammation. We show that several types of immune cells infiltrate the adipose tissue and these include macrophages, neutrophils, NK cells, innate lymphoid cells, eosinophils, T cells, B1, and B2 cells. Our main focus is how the adipose tissue affects immune responses, in particular B cell responses and antibody production. The role of leptin in generating inflammation and decreased B cell responses is also discussed. We report data published by us and by other groups showing that the adipose tissue generates pro-inflammatory B cell subsets which induce pro-inflammatory T cells, promote insulin resistance, and secrete pathogenic autoimmune antibodies.

  4. Adipose tissue as an endocrine organ.

    PubMed

    McGown, Christine; Birerdinc, Aybike; Younossi, Zobair M

    2014-02-01

    Obesity is one of the most important health challenges faced by developed countries and is increasingly affecting adolescents and children. Obesity is also a considerable risk factor for the development of numerous other chronic diseases, such as insulin resistance, type 2 diabetes, heart disease and nonalcoholic fatty liver disease. The epidemic proportions of obesity and its numerous comorbidities are bringing into focus the highly complex and metabolically active adipose tissue. Adipose tissue is increasingly being considered as a functional endocrine organ. This article discusses the endocrine effects of adipose tissue during obesity and the systemic impact of this signaling. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Forkhead box A3 mediates glucocorticoid receptor function in adipose tissue.

    PubMed

    Ma, Xinran; Xu, Lingyan; Mueller, Elisabetta

    2016-03-22

    Glucocorticoids (GCs) are widely prescribed anti-inflammatory agents, but their chronic use leads to undesirable side effects such as excessive expansion of adipose tissue. We have recently shown that the forkhead box protein A3 (Foxa3) is a calorie-hoarding factor that regulates the selective enlargement of epididymal fat depots and suppresses energy expenditure in a nutritional- and age-dependent manner. It has been demonstrated that Foxa3 levels are elevated in adipose depots in response to high-fat diet regimens and during the aging process; however no studies to date have elucidated the mechanisms that control Foxa3's expression in fat. Given the established effects of GCs in increasing visceral adiposity and in reducing thermogenesis, we assessed the existence of a possible link between GCs and Foxa3. Computational prediction analysis combined with molecular studies revealed that Foxa3 is regulated by the glucocorticoid receptor (GR) in preadipocytes, adipocytes, and adipose tissues and is required to facilitate the binding of the GR to its target gene promoters in fat depots. Analysis of the long-term effects of dexamethasone treatment in mice revealed that Foxa3 ablation protects mice specifically against fat accretion but not against other pathological side effects elicited by this synthetic GC in tissues such as liver, muscle, and spleen. In conclusion our studies provide the first demonstration, to our knowledge, that Foxa3 is a direct target of GC action in adipose tissues and point to a role of Foxa3 as a mediator of the side effects induced in fat tissues by chronic treatment with synthetic steroids.

  6. Regulation of metabolic health and adipose tissue function by group 2 innate lymphoid cells.

    PubMed

    Cautivo, Kelly M; Molofsky, Ari B

    2016-06-01

    Adipose tissue (AT) is home to an abundance of immune cells. With chronic obesity, inflammatory immune cells accumulate and promote insulin resistance and the progression to type 2 diabetes mellitus. In contrast, recent studies have highlighted the regulation and function of immune cells in lean, healthy AT, including those associated with type 2 or "allergic" immunity. Although traditionally activated by infection with multicellular helminthes, AT type 2 immunity is active independently of infection, and promotes tissue homeostasis, AT "browning," and systemic insulin sensitivity, protecting against obesity-induced metabolic dysfunction and type 2 diabetes mellitus. In particular, group 2 innate lymphoid cells (ILC2s) are integral regulators of AT type 2 immunity, producing the cytokines interleukin-5 and IL-13, promoting eosinophils and alternatively activated macrophages, and cooperating with and promoting AT regulatory T (Treg) cells. In this review, we focus on the recent developments in our understanding of group 2 innate lymphoid cell cells and type 2 immunity in AT metabolism and homeostasis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Brown adipose tissue and its therapeutic potential.

    PubMed

    Lidell, M E; Betz, M J; Enerbäck, S

    2014-10-01

    Obesity and related diseases are a major cause of human morbidity and mortality and constitute a substantial economic burden for society. Effective treatment regimens are scarce, and new therapeutic targets are needed. Brown adipose tissue, an energy-expending tissue that produces heat, represents a potential therapeutic target. Its presence is associated with low body mass index, low total adipose tissue content and a lower risk of type 2 diabetes mellitus. Knowledge about the development and function of thermogenic adipocytes in brown adipose tissue has increased substantially in the last decade. Important transcriptional regulators have been identified, and hormones able to modulate the thermogenic capacity of the tissue have been recognized. Intriguingly, it is now clear that humans, like rodents, possess two types of thermogenic adipocytes: the classical brown adipocytes found in the interscapular brown adipose organ and the so-called beige adipocytes primarily found in subcutaneous white adipose tissue after adrenergic stimulation. The presence of two distinct types of energy-expending adipocytes in humans is conceptually important because these cells might be stimulated and recruited by different signals, raising the possibility that they might be separate potential targets for therapeutic intervention. In this review, we will discuss important features of the energy-expending brown adipose tissue and highlight those that may serve as potential targets for pharmacological intervention aimed at expanding the tissue and/or enhancing its function to counteract obesity.

  8. Regulation and Function of FTO mRNA Expression in Human Skeletal Muscle and Subcutaneous Adipose Tissue

    PubMed Central

    Grunnet, Louise G.; Nilsson, Emma; Ling, Charlotte; Hansen, Torben; Pedersen, Oluf; Groop, Leif; Vaag, Allan; Poulsen, Pernille

    2009-01-01

    OBJECTIVE Common variants in FTO (the fat mass– and obesity-associated gene) associate with obesity and type 2 diabetes. The regulation and biological function of FTO mRNA expression in target tissue is unknown. We investigated the genetic and nongenetic regulation of FTO mRNA in skeletal muscle and adipose tissue and their influence on in vivo glucose and fat metabolism. RESEARCH DESIGN AND METHODS The FTO rs9939609 polymorphism was genotyped in two twin cohorts: 1) 298 elderly twins aged 62–83 years with glucose tolerance ranging from normal to type 2 diabetes and 2) 196 young (25–32 years) and elderly (58–66 years) nondiabetic twins examined by a hyperinsulinemic-euglycemic clamp including indirect calorimetry. FTO mRNA expression was determined in subcutaneous adipose tissue (n = 226) and skeletal muscle biopsies (n = 158). RESULTS Heritability of FTO expression in both tissues was low, and FTO expression was not influenced by FTO rs9939609 genotype. FTO mRNA expression in skeletal muscle was regulated by age and sex, whereas age and BMI were predictors of adipose tissue FTO mRNA expression. FTO mRNA expression in adipose tissue was associated with an atherogenic lipid profile. In skeletal muscle, FTO mRNA expression was negatively associated to fat and positively to glucose oxidation rates as well as positively correlated with expression of genes involved in oxidative phosphorylation including PGC1α. CONCLUSIONS The heritability of FTO expression in adipose tissue and skeletal muscle is low and not influenced by obesity-associated FTO genotype. The age-dependent decline in FTO expression is associated with peripheral defects of glucose and fat metabolism. PMID:19587359

  9. Regulation and function of FTO mRNA expression in human skeletal muscle and subcutaneous adipose tissue.

    PubMed

    Grunnet, Louise G; Nilsson, Emma; Ling, Charlotte; Hansen, Torben; Pedersen, Oluf; Groop, Leif; Vaag, Allan; Poulsen, Pernille

    2009-10-01

    Common variants in FTO (the fat mass- and obesity-associated gene) associate with obesity and type 2 diabetes. The regulation and biological function of FTO mRNA expression in target tissue is unknown. We investigated the genetic and nongenetic regulation of FTO mRNA in skeletal muscle and adipose tissue and their influence on in vivo glucose and fat metabolism. The FTO rs9939609 polymorphism was genotyped in two twin cohorts: 1) 298 elderly twins aged 62-83 years with glucose tolerance ranging from normal to type 2 diabetes and 2) 196 young (25-32 years) and elderly (58-66 years) nondiabetic twins examined by a hyperinsulinemic-euglycemic clamp including indirect calorimetry. FTO mRNA expression was determined in subcutaneous adipose tissue (n = 226) and skeletal muscle biopsies (n = 158). Heritability of FTO expression in both tissues was low, and FTO expression was not influenced by FTO rs9939609 genotype. FTO mRNA expression in skeletal muscle was regulated by age and sex, whereas age and BMI were predictors of adipose tissue FTO mRNA expression. FTO mRNA expression in adipose tissue was associated with an atherogenic lipid profile. In skeletal muscle, FTO mRNA expression was negatively associated to fat and positively to glucose oxidation rates as well as positively correlated with expression of genes involved in oxidative phosphorylation including PGC1alpha. The heritability of FTO expression in adipose tissue and skeletal muscle is low and not influenced by obesity-associated FTO genotype. The age-dependent decline in FTO expression is associated with peripheral defects of glucose and fat metabolism.

  10. Sex differences in adipose tissue

    PubMed Central

    Fuente-Martín, Esther; Argente-Arizón, Pilar; Ros, Purificación; Argente, Jesús; Chowen, Julie A

    2013-01-01

    Obesity and its associated secondary complications are active areas of investigation in search of effective treatments. As a result of this intensified research numerous differences between males and females at all levels of metabolic control have come to the forefront. These differences include not only the amount and distribution of adipose tissue, but also differences in its metabolic capacity and functions between the sexes. Here, we review some of the recent advances in our understanding of these dimorphisms and emphasize the fact that these differences between males and females must be taken into consideration in hopes of obtaining successful treatments for both sexes. PMID:23991358

  11. Depot-specific effects of treadmill running and rutin on white adipose tissue function in diet-induced obese mice.

    PubMed

    Chen, Neng; Lei, Ting; Xin, Lili; Zhou, Lingmei; Cheng, Jinbo; Qin, Liqiang; Han, Shufen; Wan, Zhongxiao

    2016-09-01

    White adipose tissue (WAT) is a critical organ involved in regulating metabolic homeostasis under obese condition. Strategies that could positively affect WAT function would hold promise for fighting against obesity and its complications. The aim of the present study is to explore the effects of treadmill exercise training and rutin intervention on adipose tissue function from diet-induced obese (DIO) mice and whether fat depot-specific effects existed. In epididymal adipose tissue, high-fat diet (HFD) resulted in reduction in adiponectin mRNA expression, peroxisome proliferator-activated receptors (PPAR)-γ and DsbA-L protein expression, elevation in endoplasmic reticulum (ER) stress markers including 78 kDa glucose-regulated protein (GRP-78), C/EBP homologous protein (CHOP) and p-c-Jun N-terminal kinase (JNK). Isoproterenol-stimulated lipolysis and insulin stimulated Akt phosphorylation ex vivo were blunted from HFD group. The combination of rutin with exercise (HRE) completely restored GRP78 and p-JNK protein expression to normal levels, as well as blunted signaling ex vivo. In inguinal adipose tissue, HFD led to increased adiponectin mRNA expression, PPAR-γ, GRP78, and p-JNK protein expression, and reduction in DsbA-L. HRE is effective for restoring p-JNK, PPAR-γ, and DsbA-L. In conclusion, depot-specific effects may exist in regard to the effects of rutin and exercise on key molecules involved in regulating adipose tissue function (i.e., ER stress markers, PPAR-γ and DsbA-L, adiponectin expression, and secretion, ex vivo catecholamine stimulated lipolysis and insulin stimulated Akt phosphorylation) from DIO mice.

  12. Ageing, adipose tissue, fatty acids and inflammation.

    PubMed

    Pararasa, Chathyan; Bailey, Clifford J; Griffiths, Helen R

    2015-04-01

    A common feature of ageing is the alteration in tissue distribution and composition, with a shift in fat away from lower body and subcutaneous depots to visceral and ectopic sites. Redistribution of adipose tissue towards an ectopic site can have dramatic effects on metabolic function. In skeletal muscle, increased ectopic adiposity is linked to insulin resistance through lipid mediators such as ceramide or DAG, inhibiting the insulin receptor signalling pathway. Additionally, the risk of developing cardiovascular disease is increased with elevated visceral adipose distribution. In ageing, adipose tissue becomes dysfunctional, with the pathway of differentiation of preadipocytes to mature adipocytes becoming impaired; this results in dysfunctional adipocytes less able to store fat and subsequent fat redistribution to ectopic sites. Low grade systemic inflammation is commonly observed in ageing, and may drive the adipose tissue dysfunction, as proinflammatory cytokines are capable of inhibiting adipocyte differentiation. Beyond increased ectopic adiposity, the effect of impaired adipose tissue function is an elevation in systemic free fatty acids (FFA), a common feature of many metabolic disorders. Saturated fatty acids can be regarded as the most detrimental of FFA, being capable of inducing insulin resistance and inflammation through lipid mediators such as ceramide, which can increase risk of developing atherosclerosis. Elevated FFA, in particular saturated fatty acids, maybe a driving factor for both the increased insulin resistance, cardiovascular disease risk and inflammation in older adults.

  13. DJ-1 maintains energy and glucose homeostasis by regulating the function of brown adipose tissue

    PubMed Central

    Wu, Rong; Liu, Xiao-meng; Sun, Jian-guang; Chen, Hong; Ma, Jun; Dong, Meng; Peng, Shengyi; Wang, Ji-qiu; Ding, Jian-qing; Li, Dong-hao; Speakman, John R; Ning, Guang; Jin, Wanzhu; Yuan, Zengqiang

    2017-01-01

    DJ-1 protein is involved in multiple physiological processes, including Parkinson’s disease. However, the role of DJ-1 in the metabolism is largely unknown. Here we found that DJ-1 maintained energy balance and glucose homeostasis via regulating brown adipose tissue (BAT) activity. DJ-1-deficient mice reduced body mass, increased energy expenditure and improved insulin sensitivity. DJ-1 deletion also resisted high-fat-diet (HFD) induced obesity and insulin resistance. Accordingly, DJ-1 transgene triggered autonomous obesity and glucose intolerance. Further BAT transplantation experiments clarified DJ-1 regulates energy and glucose homeostasis by modulating BAT function. Mechanistically, we found that DJ-1 promoted PTEN proteasomal degradation via an E3 ligase, mind bomb-2 (Mib2), which led to Akt activation and inhibited FoxO1-dependent Ucp1 (Uncoupling protein-1) expression in BAT. Consistently, ablation of Akt1 mitigated the obesity and BAT dysfunction induced by DJ-1 transgene. These findings define a new biological role of DJ-1 protein in regulating BAT function, with an implication of the therapeutic target in the treatment of metabolic disorders. PMID:28224045

  14. Increased Oxidative Stress Impairs Adipose Tissue Function in Sphingomyelin Synthase 1 Null Mice

    PubMed Central

    Nishimura, Naotaka; Gotoh, Tomomi; Watanabe, Ken; Ikeda, Kazutaka; Garan, Yohei; Taguchi, Ryo; Node, Koichi; Okazaki, Toshiro; Oike, Yuichi

    2013-01-01

    Sphingomyelin synthase 1 (SMS1) catalyzes the conversion of ceramide to sphingomyelin. Here, we found that SMS1 null mice showed lipodystrophic phenotype. Mutant mice showed up-regulation of plasma triglyceride concentrations accompanied by reduction of white adipose tissue (WAT) as they aged. Lipoprotein lipase (LPL) activity was severely reduced in mutant mice. In vivo analysis indicated that fatty acid uptake in WAT but not in liver decreased in SMS1 null compared to wild-type mice. In vitro analysis using cultured cell revealed that SMS1 depletion reduced fatty acid uptake. Proteins extracted from WAT of mutant mice were severely modified by oxidative stress, and up-regulation of mRNAs related to apoptosis, redox adjustment, mitochondrial stress response and mitochondrial biogenesis was observed. ATP content of WAT was reduced in SMS1 null mice. Blue native gel analysis indicated that accumulation of mitochondrial respiratory chain complexes was reduced. These results suggest that WAT of SMS1 null mice is severely damaged by oxidative stress and barely functional. Indeed, mutant mice treated with the anti-oxidant N-acetyl cysteine (NAC) showed partial recovery of lipodystrophic phenotypes together with normalized plasma triglyceride concentrations. Altogether, our data suggest that SMS1 is crucial to control oxidative stress in order to maintain WAT function. PMID:23593476

  15. DJ-1 maintains energy and glucose homeostasis by regulating the function of brown adipose tissue.

    PubMed

    Wu, Rong; Liu, Xiao-Meng; Sun, Jian-Guang; Chen, Hong; Ma, Jun; Dong, Meng; Peng, Shengyi; Wang, Ji-Qiu; Ding, Jian-Qing; Li, Dong-Hao; Speakman, John R; Ning, Guang; Jin, Wanzhu; Yuan, Zengqiang

    2017-01-01

    DJ-1 protein is involved in multiple physiological processes, including Parkinson's disease. However, the role of DJ-1 in the metabolism is largely unknown. Here we found that DJ-1 maintained energy balance and glucose homeostasisvia regulating brown adipose tissue (BAT) activity. DJ-1-deficient mice reduced body mass, increased energy expenditure and improved insulin sensitivity. DJ-1 deletion also resisted high-fat-diet (HFD) induced obesity and insulin resistance. Accordingly, DJ-1 transgene triggered autonomous obesity and glucose intolerance. Further BAT transplantation experiments clarified DJ-1 regulates energy and glucose homeostasis by modulating BAT function. Mechanistically, we found that DJ-1 promoted PTEN proteasomal degradation via an E3 ligase, mind bomb-2 (Mib2), which led to Akt activation and inhibited FoxO1-dependent Ucp1 (Uncoupling protein-1) expression in BAT. Consistently, ablation of Akt1 mitigated the obesity and BAT dysfunction induced by DJ-1 transgene. These findings define a new biological role of DJ-1 protein in regulating BAT function, with an implication of the therapeutic target in the treatment of metabolic disorders.

  16. Cardiac adipose tissue and atrial fibrillation: the perils of adiposity.

    PubMed

    Hatem, Stéphane N; Redheuil, Alban; Gandjbakhch, Estelle

    2016-04-01

    The amount of adipose tissue that accumulates around the atria is associated with the risk, persistence, and severity of atrial fibrillation (AF). A strong body of clinical and experimental evidence indicates that this relationship is not an epiphenomenon but is the result of complex crosstalk between the adipose tissue and the neighbouring atrial myocardium. For instance, epicardial adipose tissue is a major source of adipokines, inflammatory cytokines, or reactive oxidative species, which can contribute to the fibrotic remodelling of the atrial myocardium. Fibro-fatty infiltrations of the subepicardium could also contribute to the functional disorganization of the atrial myocardium. The observation that obesity is associated with distinct structural and functional remodelling of the atria has opened new perspectives of treating AF substrate with aggressive risk factor management. Advances in cardiac imaging should lead to an improved ability to visualize myocardial fat depositions and to localize AF substrates.

  17. Influencing Factors of Thermogenic Adipose Tissue Activity

    PubMed Central

    Zhang, Guoqing; Sun, Qinghua; Liu, Cuiqing

    2016-01-01

    Obesity is an escalating public health challenge and contributes tremendously to the disease burden globally. New therapeutic strategies are required to alleviate the health impact of obesity-related metabolic dysfunction. Brown adipose tissue (BAT) is specialized for dissipating chemical energy for thermogenesis as a defense against cold environment. Intriguingly, the brown-fat like adipocytes that dispersed throughout white adipose tissue (WAT) in rodents and humans, called “brite” or “beige” adipocytes, share similar thermogenic characteristics to brown adipocytes. Recently, researchers have focused on cognition of these thermogenic adipose tissues. Some factors have been identified to regulate the development and function of thermogenic adipose tissues. Cold exposure, pharmacological conditions, and lifestyle can enhance non-shivering thermogenesis and metabolism via some mechanisms. However, environmental pollutants, such as ambient fine particulates and ozone, may impair the function of these thermogenic adipose tissues and thereby induce metabolic dysfunction. In this review, the origin, function and influencing factors of thermogenic adipose tissues were summarized and it will provide insights into identifying new therapeutic strategies for the treatment of obesity and obesity-related diseases. PMID:26903879

  18. Two-photon excited fluorescence of intrinsic fluorophores enables label-free assessment of adipose tissue function

    NASA Astrophysics Data System (ADS)

    Alonzo, Carlo Amadeo; Karaliota, Sevasti; Pouli, Dimitra; Liu, Zhiyi; Karalis, Katia P.; Georgakoudi, Irene

    2016-08-01

    Current methods for evaluating adipose tissue function are destructive or have low spatial resolution. These limit our ability to assess dynamic changes and heterogeneous responses that occur in healthy or diseased subjects, or during treatment. Here, we demonstrate that intrinsic two-photon excited fluorescence enables functional imaging of adipocyte metabolism with subcellular resolution. Steady-state and time-resolved fluorescence from intracellular metabolic co-factors and lipid droplets can distinguish the functional states of excised white, brown, and cold-induced beige fat. Similar optical changes are identified when white and brown fat are assessed in vivo. Therefore, these studies establish the potential of non-invasive, high resolution, endogenous contrast, two-photon imaging to identify distinct adipose tissue types, monitor their functional state, and characterize heterogeneity of induced responses.

  19. Adipose Tissue Resting Energy Expenditure and Expression of Genes Involved in Mitochondrial Function Are Higher in Women than in Men

    PubMed Central

    Nookaew, Intawat; Jacobson, Peter; Jernås, Margareta; Taube, Magdalena; Larsson, Ingrid; Andersson-Assarsson, Johanna C.; Sjöström, Lars; Froguel, Philippe; Walley, Andrew; Nielsen, Jens; Carlsson, Lena M. S.

    2013-01-01

    Context: Men and women differ in body fat distribution and adipose tissue metabolism as well as in obesity comorbidities and their response to obesity treatment. Objective: The objective of the study was a search for sex differences in adipose tissue function. Design and Setting: This was an exploratory study performed at a university hospital. Participants and Main Outcome Measures: Resting metabolic rate (RMR), body composition, and sc adipose tissue genome-wide expression were measured in the SOS Sib Pair study (n = 732). Results: The relative contribution of fat mass to RMR and the metabolic rate per kilogram adipose tissue was higher in women than in men (P value for sex by fat mass interaction = .0019). Women had increased expression of genes involved in mitochondrial function, here referred to as a mitochondrial gene signature. Analysis of liver, muscle, and blood showed that the pronounced mitochondrial gene signature in women was specific for adipose tissue. Brown adipocytes are dense in mitochondria, and the expression of the brown adipocyte marker uncoupling protein 1 was 5-fold higher in women compared with men in the SOS Sib Pair Study (P = 7.43 × 10−7), and this was confirmed in a cross-sectional, population-based study (n = 83, 6-fold higher in women, P = .00256). Conclusions: The increased expression of the brown adipocyte marker uncoupling protein 1 in women indicates that the higher relative contribution of the fat mass to RMR in women is in part explained by an increased number of brown adipocytes. PMID:23264395

  20. Flow Cytometry Analyses of Adipose Tissue Macrophages

    PubMed Central

    Cho, Kae Won; Morris, David L.; Lumeng, Carey N.

    2014-01-01

    Within adipose tissue, multiple leukocyte interactions contribute to metabolic homeostasis in health as well as to the pathogenesis of insulin resistance with obesity. Adipose tissue macrophages (ATMs) are the predominant leukocyte population in fat and contribute to obesity-induced inflammation. Characterization of ATMs and other leukocytes in the stromal vascular fraction from fat has benefited from the use of flow cytometry and flow-assisted cell sorting techniques. These methods permit the immunophenotyping, quantification, and purification of these unique cell populations from multiple adipose tissue depots in rodents and humans. Proper isolation, quantification, and characterization of ATM phenotypes are critical for understanding their role in adipose tissue function and obesity-induced metabolic diseases. Here, we present the flow cytometry protocols for phenotyping ATMs in lean and obese mice employed by our laboratory. PMID:24480353

  1. Very-long-chain ω-3 fatty acid supplements and adipose tissue functions: a randomized controlled trial.

    PubMed

    Hames, Kazanna C; Morgan-Bathke, Maria; Harteneck, Debra A; Zhou, Lendia; Port, John D; Lanza, Ian R; Jensen, Michael D

    2017-06-01

    Background: Increased omega-3 (n-3) fatty acid consumption is reported to benefit patients with metabolic syndrome, possibly due to improved adipose tissue function.Objective: We tested the effects of high-dose, very-long-chain ω-3 fatty acids on adipose tissue inflammation and insulin regulation of lipolysis.Design: A double-blind, placebo-controlled study compared 6 mo of 3.9 g eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)/d (4.2 g total ω-3/d; n = 12) with a placebo (4.2 g oleate/d; n = 9) in insulin-resistant adults. Before and after treatment, the volunteers underwent adipose tissue biopsies to measure the total (CD68(+)), pro- (CD14(+) = M1), and anti- (CD206(+) = M2) inflammatory macrophages, crown-like structures, and senescent cells, as well as a 2-step pancreatic clamping with a [U-(13)C]palmitate infusion to determine the insulin concentration needed to suppress palmitate flux by 50% (IC50(palmitate)f).Results: In the ω-3 group, the EPA and DHA contributions to plasma free fatty acids increased (P = 0.0003 and P = 0.003, respectively), as did the EPA and DHA content in adipose tissue (P < 0.0001 and P < 0.0001, respectively). Despite increases in adipose and plasma EPA and DHA in the ω-3 group, there were no significant changes in the IC50(palmitate)f (19 ± 2 compared with 24 ± 3 μIU/mL), adipose macrophages (total: 31 ± 2/100 adipocytes compared with 33 ± 2/100 adipocytes; CD14(+): 13 ± 2/100 adipocytes compared with 14 ± 2/100 adipocytes; CD206(+): 28 ± 2/100 adipocytes compared with 29 ± 3/100 adipocytes), crown-like structures (1 ± 0/10 images compared with 1 ± 0/10 images), or senescent cells (4% ± 1% compared with 4% ± 1%). There were no changes in these outcomes in the placebo group.Conclusions: Six months of high-dose ω-3 supplementation raised plasma and adipose ω-3 fatty acid concentrations but had no beneficial effects on adipose tissue lipolysis or inflammation in insulin-resistant adults. This trial was

  2. Carbon monoxide reverses adipose tissue inflammation and insulin resistance upon loss of ovarian function.

    PubMed

    Choi, Eun-Kyung; Park, Hyun-Jung; Sul, Ok-Joo; Rajasekaran, Monisha; Yu, Rina; Choi, Hye-Seon

    2015-04-15

    We hypothesized that carbon monoxide (CO) might suppress chronic inflammation, which led to metabolic disturbances. Ovariectomy (OVX) was performed in mice to mimic chronic inflammation secondary to loss of ovarian function. OVX increased fat mass and the infiltration of highly inflammatory CD11c cells into adipose tissue (AT), resulting in a disturbance of glucose metabolism. Treatment of CO attenuated these; CO decreased recruitment of CD11c-expressing cells in AT and reduced expression of CD11c in bone marrow-derived macrophages, protecting them from M1 polarization. Upregulated cGMP and decreased reactive oxygen species were responsible for the inhibitory activity of CO on CD11c expression; knockdown of soluble guanylate cyclase or heme oxygenase-1 using small interfering RNAs reduced this inhibition substantially. Improved OVX-induced insulin resistance (IR) by CO was highly associated with its activity to attenuate AT inflammation. Our results suggest a therapeutic value of CO to treat postmenopausal IR by reducing AT inflammation. Copyright © 2015 the American Physiological Society.

  3. Functional characteristics of mesenchymal stem cells derived from the adipose tissue of a patient with achondroplasia.

    PubMed

    Park, Jeong-Ran; Lee, Hanbyeol; Kim, Chung-Hyo; Hong, Seok-Ho; Ha, Kwon-Soo; Yang, Se-Ran

    2016-05-01

    Mesenchymal stem cells (MSCs) can be isolated from various tissues including bone marrow, adipose tissue, skin dermis, and umbilical Wharton's jelly as well as injured tissues. MSCs possess the capacity for self-renewal and the potential for differentiation into adipogenic, osteogenic, and chondrogenic lineages. However, the characteristics of MSCs in injured tissues, such as achondroplasia (ACH), are not well known. In this study, we isolated MSCs from human subcutaneous adipose (ACH-SAMSCs) tissue and circumjacent human adipose tissue of the cartilage (ACH-CAMSCs) from a patient with ACH. We then analyzed the characterization of ACH-SAMSCs and ACH-CAMSCs, compared with normal human dermis-derived MSCs (hDMSCs). In flow cytometry analysis, the isolated ACH-MSCs expressed low levels of CD73, CD90, and CD105, compared with hDMSCs. Moreover, both ACH- SAMSCs and ACH-CAMSCs had constitutionally overactive fibroblast growth factor receptor 3 (FGFR3) and exhibited significantly reduced osteogenic differentiation, compared to enhanced adipogenic differentiation. The activity of extracellular signal-regulated kinases 1/2 (ERK1/2) and p38 mitogen-activated protein kinases (p38 MAPK) was increased in ACH-MSCs. In addition, the efficacy of osteogenic differentiation was slightly restored in osteogenic differentiation medium with MAPKs inhibitors. These results suggest that they play essential roles in MSC differentiation toward adipogenesis in ACH pathology. In conclusion, the identification of the characteristics of ACH-MSCs and the favoring of adipogenic differentiation via the FGFR3/MAPK axis might help to elucidate the pathogenic mechanisms relevant to other skeletal diseases and could provide targets for therapeutic interventions.

  4. [New anatomo clinic approach of adipose tissue].

    PubMed

    Dardour, J-C

    2012-10-01

    For a long time, adipose tissue was supposed to be inert with only a function of long-term energetic reserve. The obesity, abnormal accumulation of fat, for its part has always been considered the sole result of hyperphagia, itself secondary to a lack of willingness of the subject. This article focuses on the multiple aspects and functions of the different fatty tissues. One must distinguish brown adipose tissue (AT) and the white AT. This includes visceral fat and subcutaneous AT, which itself is divided into two sectors, a genetic fat and grease that we called ecological. The brown adipose tissue has essentially a function of thermogenesis. Visceral adipose tissue (VAT), from a certain volume, behaves as true endocrine gland acting on glycemic and lipid function. In addition to its role of energy reserve, the sub cutaneous AT has a mechanical role of shock absorber and fabric slip. We will emphasize finally the genetic aspect still too misunderstood and underestimated that regulates the different functions of the adipose tissue.

  5. Relationship of brown adipose tissue perfusion and function: a study through β2-adrenoreceptor stimulation.

    PubMed

    Ernande, Laura; Stanford, Kristin I; Thoonen, Robrecht; Zhang, Haihua; Clerte, Maëva; Hirshman, Michael F; Goodyear, Laurie J; Bloch, Kenneth D; Buys, Emmanuel S; Scherrer-Crosbie, Marielle

    2016-04-15

    Brown adipose tissue (BAT) activation increases glucose and lipid consumption; as such, it is been considered as a potential therapy to decrease obesity. BAT is highly vascularized and its activation is associated with a necessary increase in blood flow. However, whether increasing BAT blood flow per se increases BAT activity is unknown. To examine this hypothesis, we investigated whether an isolated increase in BAT blood flow obtained by β2-adrenoreceptor (β2-AR) stimulation with salbutamol increased BAT activity. BAT blood flow was estimated in vivo in mice using contrast-enhanced ultrasound. The absence of direct effect of salbutamol on the function of isolated brown adipocytes was assessed by measuring oxygen consumption. The effect of salbutamol on BAT activity was investigated by measuring BAT glucose uptake in vivo. BAT blood flow increased by 2.3 ± 0.6-fold during β2-AR stimulation using salbutamol infusion in mice (P= 0.003). β2-AR gene expression was detectable in BAT but was extremely low in isolated brown adipocytes. Oxygen consumption of isolated brown adipocytes did not change with salbutamol exposure, confirming the absence of a direct effect of β2-AR agonist on brown adipocytes. Finally, β2-AR stimulation by salbutamol increased BAT glucose uptake in vivo (991 ± 358 vs. 135 ± 49 ng glucose/mg tissue/45 min in salbutamol vs. saline injected mice, respectively,P= 0.046). In conclusion, an increase in BAT blood flow without direct stimulation of the brown adipocytes is associated with increased BAT metabolic activity. Increasing BAT blood flow might represent a new therapeutic target in obesity.

  6. Functional brown adipose tissue limits cardiomyocyte injury and adverse remodeling in catecholamine-induced cardiomyopathy

    PubMed Central

    Thoonen, Robrecht; Ernande, Laura; Cheng, Juan; Nagasaka, Yasuko; Yao, Vincent; Miranda-Bezerra, Alexandre; Chen, Chan; Chao, Wei; Panagia, Marcello; Sosnovik, David E.; Puppala, Dheeraj; Armoundas, Antonis A.; Hindle, Allyson; Bloch, Kenneth D.; Buys, Emmanuel S.; Scherrer-Crosbie, Marielle

    2015-01-01

    Brown adipose tissue (BAT) has well recognized thermogenic properties mediated by uncoupling protein 1 (UCP1); more recently, BAT has been demonstrated to modulate cardiovascular risk factors. To investigate whether BAT also affects myocardial injury and remodeling, UCP1-deficient (UCP1−/−) mice, which have dysfunctional BAT, were subjected to catecholamine-induced cardiomyopathy. At baseline, there were no differences in echocardiographic parameters, plasma cardiac troponin I (cTnI) or myocardial fibrosis between wild-type (WT) and UCP1−/− mice. Isoproterenol infusion increased cTnI and myocardial fibrosis and induced left ventricular (LV) hypertrophy in both WT and UCP1−/− mice. UCP1−/− mice also demonstrated exaggerated myocardial injury, fibrosis, and adverse remodeling, as well as decreased survival. Transplantation of WT BAT to UCP1−/− mice prevented the isoproterenol-induced cTnI increase and improved survival, whereas UCP1−/− BAT transplanted to either UCP1−/− or WT mice had no effect on cTnI release. After 3 days of isoproterenol treatment, phosphorylated AKT and ERK were lower in the LV's of UCP1−/− mice than in those of WT mice. Activation of BAT was also noted in a model of chronic ischemic cardiomyopathy, and was correlated to LV dysfunction. Deficiency in UCP1, and accompanying BAT dysfunction, increases cardiomyocyte injury and adverse LV remodeling, and decreases survival in a mouse model of catecholamine-induced cardiomyopathy. Myocardial injury and decreased survival are rescued by transplantation of functional BAT to UCP1−/− mice, suggesting a systemic cardioprotective role of functional BAT. BAT is also activated in chronic ischemic cardiomyopathy. PMID:25968336

  7. Intrinsic circannual regulation of brown adipose tissue form and function in tune with hibernation

    PubMed Central

    Hindle, Allyson G.

    2013-01-01

    Winter hibernators repeatedly cycle between cold torpor and rewarming supported by nonshivering thermogenesis in brown adipose tissue (BAT). In contrast, summer animals are homeotherms, undergoing reproduction, growth, and fattening. This life history confers variability to BAT recruitment and activity. To address the components underlying prewinter enhancement and winter activation, we interrogated the BAT proteome in 13-lined ground squirrels among three summer and five winter states. We also examined mixed physiology in fall and spring individuals to test for ambient temperature and seasonal effects, as well as the timing of seasonal transitions. BAT form and function differ circannually in these animals, as evidenced by morphology and proteome dynamics. This intrinsic pattern distinguished homeothermic groups and early vs. late winter hibernators. Homeothermic variation derived from postemergence delay in growth and substrate biosynthesis. The heterothermic proteome varied less despite extreme winter physiological shifts and was optimized to exploit lipids by enhanced fatty acid binding, β-oxidation, and mitochondrial protein translocation. Surprisingly, ambient temperature did not affect the BAT proteome during transition seasons; rather, the pronounced summer-winter shift preceded environmental changes and phenotypic progression. During fall transition, differential regulation of two fatty acid binding proteins provides further evidence of recruitment and separates proteomic preparation from successful hibernation. Abundance of FABP4 correlates with torpor bout length throughout the year, clarifying its potential function in hibernation. Metabolically active BAT is a target for treating human obesity and metabolic disorders. Understanding the hibernator's extreme and seasonally distinct recruitment and activation control strategies offers untapped potential to identify novel, therapeutically relevant regulatory pathways. PMID:24326419

  8. Functional expression of adrenoreceptors in mesenchymal stromal cells derived from the human adipose tissue.

    PubMed

    Kotova, Polina D; Sysoeva, Veronika Yu; Rogachevskaja, Olga A; Bystrova, Marina F; Kolesnikova, Alisa S; Tyurin-Kuzmin, Pyotr A; Fadeeva, Julia I; Tkachuk, Vsevolod A; Kolesnikov, Stanislav S

    2014-09-01

    Cultured mesenchymal stromal cells (MSCs) from different sources represent a heterogeneous population of proliferating non-differentiated cells that contains multipotent stem cells capable of originating a variety of mesenchymal cell lineages. Despite tremendous progress in MSC biology spurred by their therapeutic potential, current knowledge on receptor and signaling systems of MSCs is mediocre. Here we isolated MSCs from the human adipose tissue and assayed their responsivity to GPCR agonists with Ca(2+) imaging. As a whole, a MSC population exhibited functional heterogeneity. Although a variety of first messengers was capable of stimulating Ca(2+) signaling in MSCs, only a relatively small group of cells was specifically responsive to the particular GPCR agonist, including noradrenaline. RT-PCR and immunocytochemistry revealed expression of α1B-, α2A-, and β2-adrenoreceptors in MSCs. Their sensitivity to subtype-specific adrenergic agonists/antagonists and certain inhibitors of Ca(2+) signaling indicated that largely the α2A-isoform coupled to PLC endowed MSCs with sensitivity to noradrenaline. The all-or-nothing dose-dependence was characteristic of responsivity of robust adrenergic MSCs. Noradrenaline never elicited small or intermediate responses but initiated large and quite similar Ca(2+) transients at all concentrations above the threshold. The inhibitory analysis and Ca(2+) uncaging implicated Ca(2+)-induced Ca(2+) release (CICR) in shaping Ca(2+) signals elicited by noradrenaline. Evidence favored IP3 receptors as predominantly responsible for CICR. Based on the overall findings, we inferred that adrenergic transduction in MSCs includes two fundamentally different stages: noradrenaline initially triggers a local and relatively small Ca(2+) signal, which next stimulates CICR, thereby being converted into a global Ca(2+) signal. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Overall Adiposity, Adipose Tissue Distribution, and Endometriosis: A Systematic Review

    PubMed Central

    Backonja, Uba; Buck Louis, Germaine M.; Lauver, Diane R.

    2015-01-01

    Background Endometriosis has been associated with a lean body habitus. However, we do not understand whether endometriosis is also associated with other characteristics of adiposity, including adipose tissue distribution and amount of visceral adipose tissue (VAT; adipose tissue lining inner organs). Having these understandings may provide insights on how endometriosis develops—some of the physiologic actions of adipose tissue differ depending on tissue amount and location, and are related to proposed mechanisms of endometriosis development. Objectives To review the literature regarding overall adiposity, adipose tissue distribution and/or VAT, and endometriosis. Methods We reviewed and synthesized studies indexed in PubMed and/or Web of Science. We included studies that had one or more measures of overall adiposity, adipose tissue distribution, and/or VAT, and women with and without endometriosis for comparison. We summarized the findings and commented on the methods used and potential sources of bias. Results Out of 366 identified publications, 19 (5.2%) were eligible. Two additional publications were identified from reference lists. Current research included measures of overall adiposity (e.g., body figure drawings) or adipose tissue distribution (e.g., waist-to-hip ratio), but not VAT. The weight of evidence indicated that endometriosis was associated with low overall adiposity and with a preponderance of adipose tissue distributed below the waist (peripheral). Discussion Endometriosis may be associated with being lean or having peripherally distributed adipose tissue. Well-designed studies with various sampling frameworks and precise measures of adiposity and endometriosis are needed to confirm associations between adiposity measures and endometriosis, and delineate potential etiologic mechanisms underlying endometriosis. PMID:26938364

  10. Improved adipose tissue function with initiation of protease inhibitor-only ART

    PubMed Central

    Maughan, Robert T.; Feeney, Eoin R.; Capel, Emilie; Capeau, Jacqueline; Domingo, Pere; Giralt, Marta; Lange, Joep M. A.; Phanuphak, Praphan; Cooper, David A.; Reiss, Peter; Mallon, Patrick W. G.

    2016-01-01

    Objectives Use of ART containing HIV PIs has previously been associated with toxicity in subcutaneous adipose tissue (SAT), potentially contributing to the development of lipodystrophy and insulin resistance. However, the effect of PIs on SAT function in ART-naive patients independent of other ART classes is unknown. This study aimed to elucidate the effect of initiating PI-only ART on SAT function in ART-naive subjects. Methods In the HIVNAT-019 study, 48 HIV-infected, ART-naive Thai adults commencing PI-only ART comprising lopinavir/ritonavir/saquinavir for 24 weeks underwent assessments of fasting metabolic parameters and body composition. In a molecular substudy, 20 subjects underwent SAT biopsies at weeks 0, 2 and 24 for transcriptional, protein, mitochondrial DNA (mtDNA) and histological analyses. ClinicalTrials.gov registration number: NCT00400738. Results Over 24 weeks, limb fat increased (+416.4 g, P = 0.023), coinciding with larger adipocytes as indicated by decreased adipocyte density in biopsies (−32.3 cells/mm2, P = 0.047) and increased mRNA expression of adipogenesis regulator PPARG at week 2 (+58.1%, P = 0.003). Increases in mtDNA over 24 weeks (+600 copies/cell, P = 0.041), decreased NRF1 mRNA expression at week 2 (−33.7%, P < 0.001) and increased COX2/COX4 protein ratio at week 24 (+288%, P = 0.038) indicated improved mitochondrial function. Despite decreased AKT2 mRNA at week 2 (−28.6%, P = 0.002) and increased PTPN1 mRNA at week 24 (+50.3%, P = 0.016) suggesting insulin resistance, clinical insulin sensitivity [by homeostasis model assessment (HOMA-IR)] was unchanged. Conclusions Initiation of PI-only ART showed little evidence of SAT toxicity, the changes observed being consistent with a return to health rather than contributing to lipodystrophy. PMID:27516476

  11. Improved adipose tissue function with initiation of protease inhibitor-only ART.

    PubMed

    Maughan, Robert T; Feeney, Eoin R; Capel, Emilie; Capeau, Jacqueline; Domingo, Pere; Giralt, Marta; Lange, Joep M A; Phanuphak, Praphan; Cooper, David A; Reiss, Peter; Mallon, Patrick W G

    2016-11-01

    Use of ART containing HIV PIs has previously been associated with toxicity in subcutaneous adipose tissue (SAT), potentially contributing to the development of lipodystrophy and insulin resistance. However, the effect of PIs on SAT function in ART-naive patients independent of other ART classes is unknown. This study aimed to elucidate the effect of initiating PI-only ART on SAT function in ART-naive subjects. In the HIVNAT-019 study, 48 HIV-infected, ART-naive Thai adults commencing PI-only ART comprising lopinavir/ritonavir/saquinavir for 24 weeks underwent assessments of fasting metabolic parameters and body composition. In a molecular substudy, 20 subjects underwent SAT biopsies at weeks 0, 2 and 24 for transcriptional, protein, mitochondrial DNA (mtDNA) and histological analyses. ClinicalTrials.gov registration number: NCT00400738. Over 24 weeks, limb fat increased (+416.4 g, P = 0.023), coinciding with larger adipocytes as indicated by decreased adipocyte density in biopsies (-32.3 cells/mm(2), P = 0.047) and increased mRNA expression of adipogenesis regulator PPARG at week 2 (+58.1%, P = 0.003). Increases in mtDNA over 24 weeks (+600 copies/cell, P = 0.041), decreased NRF1 mRNA expression at week 2 (-33.7%, P < 0.001) and increased COX2/COX4 protein ratio at week 24 (+288%, P = 0.038) indicated improved mitochondrial function. Despite decreased AKT2 mRNA at week 2 (-28.6%, P = 0.002) and increased PTPN1 mRNA at week 24 (+50.3%, P = 0.016) suggesting insulin resistance, clinical insulin sensitivity [by homeostasis model assessment (HOMA-IR)] was unchanged. Initiation of PI-only ART showed little evidence of SAT toxicity, the changes observed being consistent with a return to health rather than contributing to lipodystrophy. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.

  12. Integrated control of brown adipose tissue.

    PubMed

    Marzetti, Emanuele; D'Angelo, Emanuela; Savera, Giulia; Leeuwenburgh, Christiaan; Calvani, Riccardo

    2016-03-01

    Brown adipose tissue (BAT) has evolved as a unique thermogenic organ that allows placental mammals to withstand cold environmental temperatures through the dissipation of metabolic energy in the form of heat. Although traditionally believed to be lost shortly after birth, metabolically active BAT depots have recently been identified in a large percentage of human adults. Besides classical brown cells, a distinct type of thermogenic adipocytes named beige or brite (brown in white) cells are recruited in white adipose tissue depots under specific stimuli. Given the well-known energy-dissipating properties of thermogenic adipose tissue and its function of metabolic sink for glucose and lipids, this tissue has attracted considerable research interest as a possible target for treating obesity and metabolic disease. The complex network of interorgan connections that regulate BAT and brite tissue mass and function is a major hurdle for the development of therapeutic strategies against metabolic disorders. This review provides an overview of the current knowledge on the regulation of BAT and brite adipose tissue function. The possibility of targeting these tissues to treat obesity and other metabolic disorders is also discussed.

  13. Integrated control of brown adipose tissue

    PubMed Central

    Marzetti, Emanuele; D’Angelo, Emanuela; Savera, Giulia; Leeuwenburgh, Christiaan; Calvani, Riccardo

    2016-01-01

    Brown adipose tissue (BAT) has evolved as a unique thermogenic organ that allows placental mammals to withstand cold environmental temperatures through the dissipation of metabolic energy in the form of heat. Although traditionally believed to be lost shortly after birth, metabolically active BAT depots have recently been identified in a large percentage of human adults. Besides classical brown cells, a distinct type of thermogenic adipocytes named beige or brite (brown in white) cells are recruited in white adipose tissue depots under specific stimuli. Given the well-known energy-dissipating properties of thermogenic adipose tissue and its function of metabolic sink for glucose and lipids, this tissue has attracted considerable research interest as a possible target for treating obesity and metabolic disease. The complex network of interorgan connections that regulate BAT and brite tissue mass and function is a major hurdle for the development of therapeutic strategies against metabolic disorders. This review provides an overview of the current knowledge on the regulation of BAT and brite adipose tissue function. The possibility of targeting these tissues to treat obesity and other metabolic disorders is also discussed. PMID:27524955

  14. Expression of functional TSH receptor in white adipose tissues of hyt/hyt mice induces lipolysis in vivo.

    PubMed

    Endo, Toyoshi; Kobayashi, Tetsuro

    2012-06-15

    To determine the relative importance of TSH in white adipose tissue, we compared the adipose phenotypes of two distinct mouse models of hypothyroidism. These models differed in that the normal reciprocal relationship between thyroid hormone and TSH was intact in one and disrupted in the other. One model, thyroidectomized (THYx) mice, had a 100-fold increase in TSH and a normal TSH receptor (TSHR); in contrast, the other model, hyt/hyt mice, had a 120-fold elevation of TSH but a nonfunctional TSHR. Although both THYx and hyt/hyt mice were in a severe hypothyroid state, the epididymal fat (mg)/body wt (g) (F/B) ratio of THYx mice was much smaller than that of hyt/hyt mice (8.2 ± 0.43 vs. 14.4 ± 0.40, respectively, P < 0.001). The fat cell diameter in THYx mice was also smaller than that in hyt/hyt mice (79 ± 2.8 vs. 105 ± 2.2 μm, respectively, P < 0.001), suggesting that TSH induced lipolysis in adipose tissues. When we transferred a functional mouse TSHR gene and a control plasmid into opposite sides of epididymal fat of hyt/hyt mice by plasmid injection combined with electroporation, fat weight of the TSHR side was decreased to 60% of that of the control side. Messenger RNA levels of hormone-sensitive lipase in epididymal fat containing the transferred TSHR gene were twofold higher than those in tissue from the control side. These results indicated that TSH worked as a lipolytic factor in white adipose tissues, especially in mice in a hypothyroid state.

  15. Adipose tissue and skeletal muscle plasticity modulates metabolic health.

    PubMed

    Ukropec, Jozef; Ukropcova, Barbara; Kurdiova, Timea; Gasperikova, Daniela; Klimes, Iwar

    2008-12-01

    Obesity, accumulation of adipose tissue, develops when energy intake exceeds energy expenditure. Adipose tissue is essential for buffering the differences between energy intake and expenditure by accumulating lipids while skeletal muscle is the energy burning machine. Here we adopted the concept that (i) adipose tissue ability to regulate the storage capacity for lipids as well as (ii) dynamic regulation of muscle and adipose tissue secretory and metabolic activity is important for maintaining the metabolic health. This might be at least in part related to tissue plasticity, a phenomenon enabling dynamic modulation of the tissue phenotype in different physiological and pathophysiological situations. Recent advances in our understanding of the complex endocrine function of adipose tissue in regulating lipid metabolism, adipogenesis, angiogenesis, extracellular matrix remodelling, inflammation and oxidative stress prompted us to review the role of tissue plasticity--dynamic changes in adipose tissue and skeletal muscle metabolic and endocrine phenotype--in determining the difference between metabolic health and disease.

  16. Circadian Rhythms in Adipose Tissue Physiology.

    PubMed

    Kiehn, Jana-Thabea; Tsang, Anthony H; Heyde, Isabel; Leinweber, Brinja; Kolbe, Isa; Leliavski, Alexei; Oster, Henrik

    2017-03-16

    The different types of adipose tissues fulfill a wide range of biological functions-from energy storage to hormone secretion and thermogenesis-many of which show pronounced variations over the course of the day. Such 24-h rhythms in physiology and behavior are coordinated by endogenous circadian clocks found in all tissues and cells, including adipocytes. At the molecular level, these clocks are based on interlocked transcriptional-translational feedback loops comprised of a set of clock genes/proteins. Tissue-specific clock-controlled transcriptional programs translate time-of-day information into physiologically relevant signals. In adipose tissues, clock gene control has been documented for adipocyte proliferation and differentiation, lipid metabolism as well as endocrine function and other adipose oscillations are under control of systemic signals tied to endocrine, neuronal, or behavioral rhythms. Circadian rhythm disruption, for example, by night shift work or through genetic alterations, is associated with changes in adipocyte metabolism and hormone secretion. At the same time, adipose metabolic state feeds back to central and peripheral clocks, adjusting behavioral and physiological rhythms. In this overview article, we summarize our current knowledge about the crosstalk between circadian clocks and energy metabolism with a focus on adipose physiology. © 2017 American Physiological Society. Compr Physiol 7:383-427, 2017.

  17. Endothelial and cardiac regeneration from adipose tissues.

    PubMed

    Casteilla, Louis; Planat-Bénard, Valérie; Dehez, Stéphanie; De Barros, Sandra; Barreau, Corinne; André, Mireille

    2011-01-01

    For a long time, adipose tissue was only considered for its crucial role in energy balance and associated diseases. The discovery of the presence of immature cells highlights a putative role for these tissues as reservoirs of therapeutic cells. Indeed, since fat pads can be sampled by liposuction under local anesthesia in adult patients, adipose tissue represents a promising source of regenerative cells, particularly in cardiovascular regeneration. Indeed among other potentials, we and others have demonstrated the great angiogenic properties of adipose-derived stromal cells (ASCs) and the existence of peculiar cells, at least in mice, that are able to spontaneously give rise to functional cardiomyocytes. This review deciphers the different steps necessary to isolate, characterize, and manipulate such striking cells.

  18. Chronic AMPK activation via loss of FLCN induces functional beige adipose tissue through PGC-1α/ERRα.

    PubMed

    Yan, Ming; Audet-Walsh, Étienne; Manteghi, Sanaz; Dufour, Catherine Rosa; Walker, Benjamin; Baba, Masaya; St-Pierre, Julie; Giguère, Vincent; Pause, Arnim

    2016-05-01

    The tumor suppressor folliculin (FLCN) forms a repressor complex with AMP-activated protein kinase (AMPK). Given that AMPK is a master regulator of cellular energy homeostasis, we generated an adipose-specific Flcn (Adipoq-FLCN) knockout mouse model to investigate the role of FLCN in energy metabolism. We show that loss of FLCN results in a complete metabolic reprogramming of adipose tissues, resulting in enhanced oxidative metabolism. Adipoq-FLCN knockout mice exhibit increased energy expenditure and are protected from high-fat diet (HFD)-induced obesity. Importantly, FLCN ablation leads to chronic hyperactivation of AMPK, which in turns induces and activates two key transcriptional regulators of cellular metabolism, proliferator-activated receptor γ (PPARγ) coactivator-1α (PGC-1α) and estrogen-related receptor α (ERRα). Together, the AMPK/PGC-1α/ERRα molecular axis positively modulates the expression of metabolic genes to promote mitochondrial biogenesis and activity. In addition, mitochondrial uncoupling proteins as well as other markers of brown fat are up-regulated in both white and brown FLCN-null adipose tissues, underlying the increased resistance of Adipoq-FLCN knockout mice to cold exposure. These findings identify a key role of FLCN as a negative regulator of mitochondrial function and identify a novel molecular pathway involved in the browning of white adipocytes and the activity of brown fat. © 2016 Yan et al.; Published by Cold Spring Harbor Laboratory Press.

  19. Chronic AMPK activation via loss of FLCN induces functional beige adipose tissue through PGC-1α/ERRα

    PubMed Central

    Yan, Ming; Audet-Walsh, Étienne; Manteghi, Sanaz; Rosa Dufour, Catherine; Walker, Benjamin; Baba, Masaya; St-Pierre, Julie; Giguère, Vincent; Pause, Arnim

    2016-01-01

    The tumor suppressor folliculin (FLCN) forms a repressor complex with AMP-activated protein kinase (AMPK). Given that AMPK is a master regulator of cellular energy homeostasis, we generated an adipose-specific Flcn (Adipoq-FLCN) knockout mouse model to investigate the role of FLCN in energy metabolism. We show that loss of FLCN results in a complete metabolic reprogramming of adipose tissues, resulting in enhanced oxidative metabolism. Adipoq-FLCN knockout mice exhibit increased energy expenditure and are protected from high-fat diet (HFD)-induced obesity. Importantly, FLCN ablation leads to chronic hyperactivation of AMPK, which in turns induces and activates two key transcriptional regulators of cellular metabolism, proliferator-activated receptor γ (PPARγ) coactivator-1α (PGC-1α) and estrogen-related receptor α (ERRα). Together, the AMPK/PGC-1α/ERRα molecular axis positively modulates the expression of metabolic genes to promote mitochondrial biogenesis and activity. In addition, mitochondrial uncoupling proteins as well as other markers of brown fat are up-regulated in both white and brown FLCN-null adipose tissues, underlying the increased resistance of Adipoq-FLCN knockout mice to cold exposure. These findings identify a key role of FLCN as a negative regulator of mitochondrial function and identify a novel molecular pathway involved in the browning of white adipocytes and the activity of brown fat. PMID:27151976

  20. Human brown adipose tissue-function and therapeutic potential in metabolic disease.

    PubMed

    Bhatt, Padmanabh Shrikant; Dhillo, Waljit S; Salem, Victoria

    2017-08-08

    There has been a resurgence of interest in brown adipose tissue (BAT) over the last decade. Key to this has been our ability to accurately image it, which has improved significantly. The role of BAT in regulating energy expenditure is important, and its pharmacological manipulation may hold therapeutic potential in metabolic disease. There is ample evidence of BAT activation by cold exposure, and pharmacological utilisation of similar pathways, using B3 receptor agonists holds promise since the development of selective agonists with limited cross-reactivity has rekindled interest. Endogenous agents like irisin, FGF21 and certain gut hormones may hold value as BAT activators. Other agents such as steroid hormones may also hold therapeutic potential, although short-term worsening of metabolic profile remains problematic. Clearly, pharmacological manipulation of BAT is important, and thanks to recent advances we may one day be able to add such agents to our anti-obesity arsenal. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Adipose Tissue - Adequate, Accessible Regenerative Material

    PubMed Central

    Kolaparthy, Lakshmi Kanth.; Sanivarapu, Sahitya; Moogla, Srinivas; Kutcham, Rupa Sruthi

    2015-01-01

    The potential use of stem cell based therapies for the repair and regeneration of various tissues offers a paradigm shift that may provide alternative therapeutic solutions for a number of diseases. The use of either embryonic stem cells (ESCs) or induced pluripotent stem cells in clinical situations is limited due to cell regulations and to technical and ethical considerations involved in genetic manipulation of human ESCs, even though these cells are highly beneficial. Mesenchymal stem cells seen to be an ideal population of stem cells in particular, Adipose derived stem cells (ASCs) which can be obtained in large number and easily harvested from adipose tissue. It is ubiquitously available and has several advantages compared to other sources as easily accessible in large quantities with minimal invasive harvesting procedure, and isolation of adipose derived mesenchymal stem cells yield a high amount of stem cells which is essential for stem cell based therapies and tissue engineering. Recently, periodontal tissue regeneration using ASCs has been examined in some animal models. This method has potential in the regeneration of functional periodontal tissues because various secreted growth factors from ASCs might not only promote the regeneration of periodontal tissues but also encourage neovascularization of the damaged tissues. This review summarizes the sources, isolation and characteristics of adipose derived stem cells and its potential role in periodontal regeneration is discussed. PMID:26634060

  2. Materials for engineering vascularized adipose tissue.

    PubMed

    Chiu, Yu-Chieh; Cheng, Ming-Huei; Uriel, Shiri; Brey, Eric M

    2011-05-01

    Loss of adipose tissue can occur due to congenital and acquired lipoatrophies, trauma, tumor resection, and chronic disease. Clinically, it is difficult to regenerate or reconstruct adipose tissue. The extensive microvsacular network present in adipose, and the sensitivity of adipocytes to hypoxia, hinder the success of typical tissue transfer procedures. Materials that promote the formation of vascularized adipose tissue may offer alternatives to current clinical treatment options. A number of synthetic and natural biomaterials common in tissue engineering have been investigated as scaffolds for adipose regeneration. While these materials have shown some promise they do not account for the unique extracellular microenvironment of adipose. Adipose derived hydrogels more closely approximate the physical and chemical microenvironment of adipose tissue, promote preadipocyte differentiation and vessel assembly in vitro, and stimulate vascularized adipose formation in vivo. The combination of these materials with techniques that promote rapid and stable vascularization could lead to new techniques for engineering stable, vascularized adipose tissue for clinical application. In this review we discuss materials used for adipose tissue engineering and strategies for vascularization of these scaffolds. Materials that promote formation of vascularized adipose tissue have the potential to serve as alternatives or supplements to existing treatment options, for adipose defects or deficiencies resulting from chronic disease, lipoatrophies, trauma, and tumor resection. Copyright © 2009 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.

  3. Differential modulation of the functionality of white adipose tissue of obese Zucker (fa/fa) rats by the type of protein and the amount and type of fat.

    PubMed

    Díaz-Villaseñor, Andrea; Granados, Omar; González-Palacios, Berenice; Tovar-Palacio, Claudia; Torre-Villalvazo, Ivan; Olivares-García, Verónica; Torres, Nimbe; Tovar, Armando R

    2013-11-01

    Recent evidence indicates that several metabolic abnormalities developed during obesity are associated with the presence of dysfunctional adipose tissue. Diet is a key factor that modulates several functions of adipose tissue; however, each nutrient in the diet produces specific changes. Thus, the aim of this work was to study the effect of the interaction of the type (coconut or soybean oil) and amount (5% or 10%) of fat with the type of dietary protein (casein or soy protein) on the functionality of white adipose tissue of Zucker (fa/fa) rats. The results showed that soybean oil reduced adipocyte size and decreased esterified saturated fatty acids in white adipose tissue. Excess dietary fat also modified the composition of esterified fatty acids in white adipose tissue, increased the secretion of saturated fatty acids to serum from white adipose tissue and reduced the process of fatty acids re-esterification. On the other hand, soy protein sensitized the activation of the hormone-sensitive lipase by increasing the phosphorylation of this enzyme (Ser 563) despite rats fed soy protein were normoglucagonemic, in contrast with rats fed casein that showed hyperglucagonemia but reduced hormone-sensitive lipase phosphorylation. Finally, in white adipose tissue, the interaction between the tested dietary components modulated the transcription/translation process of lipid and carbohydrate metabolism genes via the activity of the PERK-endoplasmic reticulum stress response. Therefore, our results showed that the type of protein and the type and amount of dietary fat selectively modify the activity of white adipose tissue, even in a genetic model of obesity. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. [White adipose tissue dysfunction observed in obesity].

    PubMed

    Lewandowska, Ewa; Zieliński, Andrzej

    2016-05-01

    Obesity is a disease with continuingly increasing prevalence. It occurs worldwide independently of age group, material status or country of origin. At these times the most common reasons for obesity are bad eating habits and dramatic reduction of physical activity, which cause the energy imbalance of organism. Fundamental alteration observed in obese subjects is white adipose tissue overgrowth, which is linked to increased incidence of obesity-related comorbidities, such as: cardiovascular diseases, type 2 diabetes or digestive tract diseases. What is more, obesity is also a risk factor for some cancers. Special risk for diseases linked to excessive weight is associated with overgrowth of visceral type of adipose tissue. Adipose tissue, which is the main energy storehouse in body and acts also as an endocrine organ, undergoes both the morphological and the functional changes in obesity, having a negative impact on whole body function. In this article we summarize the most important alterations in morphology and function of white adipose tissue, observed in obese subjects.

  5. Interactions between the gut, the brain and brown adipose tissue function.

    PubMed

    van den Beukel, Johanna C; Grefhorst, Aldo

    2014-01-01

    Brown adipose tissue (BAT) has the unique ability to oxidize fatty acids to generate heat, a process termed thermogenesis. The mitochondrial uncoupling protein 1 is predominantly expressed in BAT and controls the thermogenetic properties of this tissue. Since activated BAT dissipates energy, it is considered beneficial in controlling metabolism, i.e. by combating obesity. Indeed, humans with a higher BMI have less active BAT. Many researchers attempt to uncover regulatory pathways in BAT activity in the pursuit for novel BAT modulators to control body weight. Endocrine factors such as thyroid hormone, sex steroid hormones and glucocorticoids can modulate BAT activity. Since the intestinal tract has emerged as an endocrine organ regulating energy balance and glucose homeostasis, this review will discuss how gut-derived hormones and other intestinal tract-related factors such as bile acids modulate BAT activity. Emphasis will be put on whether these hormones regulate BAT directly or via the central nervous system. In summary, it can be globally stated that anorexigenic gut hormones stimulate BAT while orexigenic gut hormones inhibit BAT activity. How these hormones modulate BAT and whether this is via a direct and/or central effect is largely unknown. Novel insights about gut-derived factors such as bile acids suggest that they also affect BAT activity. Altogether, effects of food intake per se on BAT activity are rather complex to interpret and depend on many (hormonal) factors. © 2014 S. Karger AG, Basel.

  6. Quantification of adipose tissue insulin sensitivity.

    PubMed

    Søndergaard, Esben; Jensen, Michael D

    2016-06-01

    In metabolically healthy humans, adipose tissue is exquisitely sensitive to insulin. Similar to muscle and liver, adipose tissue lipolysis is insulin resistant in adults with central obesity and type 2 diabetes. Perhaps uniquely, however, insulin resistance in adipose tissue may directly contribute to development of insulin resistance in muscle and liver because of the increased delivery of free fatty acids to those tissues. It has been hypothesized that insulin adipose tissue resistance may precede other metabolic defects in obesity and type 2 diabetes. Therefore, precise and reproducible quantification of adipose tissue insulin sensitivity, in vivo, in humans, is an important measure. Unfortunately, no consensus exists on how to determine adipose tissue insulin sensitivity. We review the methods available to quantitate adipose tissue insulin sensitivity and will discuss their strengths and weaknesses. Copyright © 2016 American Federation for Medical Research.

  7. Adipose tissue content, muscle performance and physical function in obese adults with type 2 diabetes mellitus and peripheral neuropathy.

    PubMed

    Bittel, Daniel C; Bittel, Adam J; Tuttle, Lori J; Hastings, Mary K; Commean, Paul K; Mueller, Michael J; Cade, W Todd; Sinacore, David R

    2015-03-01

    To determine leg intermuscular (IMAT) and subcutaneous (SQAT) adipose tissue and their relationships with muscle performance and function in obese adults with and without type 2 diabetes and peripheral neuropathy (T2DMPN). Seventy-nine age-matched obese adults were studied, 13 T2DM, 54 T2DMPN, and 24 obese controls. Leg fat (%IMAT, %SQAT) volumes were quantified using MRI. Ankle plantar flexion (PF) torque and power were assessed with isokinetic dynamometry. Physical function was assessed with 9-item Physical Performance Test (PPT), 6-minute walk distance, single-limb balance, and time to ascend 10 stairs. One-way ANOVAs determined group differences, and multiple regression predicted PPT score from disease status, % IMAT, and PF power. T2DMPN participants had 37% greater IMAT volumes and 15% lower SQAT volumes than controls (p =. 01). T2DMPN and T2DM showed reduced PF torque and power compared to controls. T2DMPN participants had lower PPT score, 6-minute walk, single-limb balance, and stair climbing than controls (all p<.05). %IMAT volume correlated inversely, and %SQAT correlated directly, with PPT. Leg %IMAT and disease status predicted 49% of PPT score. T2DMPN may represent a shift in adipose tissue accumulation from SQAT to IMAT depots, which is inversely associated with muscle performance and physical function. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Deficiency of Interleukin-15 Confers Resistance to Obesity by Diminishing Inflammation and Enhancing the Thermogenic Function of Adipose Tissues

    PubMed Central

    Lacraz, Gregory; Rakotoarivelo, Volatiana; Labbé, Sebastien M.; Vernier, Mathieu; Noll, Christophe; Mayhue, Marian; Stankova, Jana; Schwertani, Adel; Grenier, Guillaume; Carpentier, André; Richard, Denis; Ferbeyre, Gerardo; Fradette, Julie; Rola-Pleszczynski, Marek; Menendez, Alfredo; Langlois, Marie-France; Ilangumaran, Subburaj; Ramanathan, Sheela

    2016-01-01

    Objective IL-15 is an inflammatory cytokine secreted by many cell types. IL-15 is also produced during physical exercise by skeletal muscle and has been reported to reduce weight gain in mice. Contrarily, our findings on IL-15 knockout (KO) mice indicate that IL-15 promotes obesity. The aim of this study is to investigate the mechanisms underlying the pro-obesity role of IL-15 in adipose tissues. Methods Control and IL-15 KO mice were maintained on high fat diet (HFD) or normal control diet. After 16 weeks, body weight, adipose tissue and skeletal mass, serum lipid levels and gene/protein expression in the adipose tissues were evaluated. The effect of IL-15 on thermogenesis and oxygen consumption was also studied in primary cultures of adipocytes differentiated from mouse preadipocyte and human stem cells. Results Our results show that IL-15 deficiency prevents diet-induced weight gain and accumulation of lipids in visceral and subcutaneous white and brown adipose tissues. Gene expression analysis also revealed elevated expression of genes associated with adaptive thermogenesis in the brown and subcutaneous adipose tissues of IL-15 KO mice. Accordingly, oxygen consumption was increased in the brown adipocytes from IL-15 KO mice. In addition, IL-15 KO mice showed decreased expression of pro-inflammatory mediators in their adipose tissues. Conclusions Absence of IL-15 results in decreased accumulation of fat in the white adipose tissues and increased lipid utilization via adaptive thermogenesis. IL-15 also promotes inflammation in adipose tissues that could sustain chronic inflammation leading to obesity-associated metabolic syndrome. PMID:27684068

  9. Adipocytes in both brown and white adipose tissue of adult mice are functionally connected via gap junctions: implications for Chagas disease.

    PubMed

    Burke, Shoshana; Nagajyothi, Fnu; Thi, Mia M; Hanani, Menachem; Scherer, Philipp E; Tanowitz, Herbert B; Spray, David C

    2014-11-01

    Adipose tissue serves as a host reservoir for the protozoan Trypanosoma cruzi, the causative organism in Chagas disease. Gap junctions interconnect cells of most tissues, serving to synchronize cell activities including secretion in glandular tissue, and we have previously demonstrated that gap junctions are altered in various tissues and cells infected with T. cruzi. Herein, we examined the gap junction protein connexin 43 (Cx43) expression in infected adipose tissues. Adipose tissue is the largest endocrine organ of the body and is also involved in other physiological functions. In mammals, it is primarily composed of white adipocytes. Although gap junctions are a prominent feature of brown adipocytes, they have not been explored extensively in white adipocytes, especially in the setting of infection. Thus, we examined functional coupling in both white and brown adipocytes in mice. Injection of electrical current or the dye Lucifer Yellow into adipocytes within fat tissue spread to adjacent cells, which was reduced by treatment with agents known to block gap junctions. Moreover, Cx43 was detected in both brown and white fat tissue. At thirty and ninety days post-infection, Cx43 was downregulated in brown adipocytes and upregulated in white adipocytes. Gap junction-mediated intercellular communication likely contributes to hormone secretion and other functions in white adipose tissue and to nonshivering thermogenesis in brown fat, and modulation of the coupling by T. cruzi infection is expected to impact these functions. Copyright © 2014. Published by Elsevier Masson SAS.

  10. Adipocytes in both brown and white adipose tissue of adult mice are functionally connected via gap junctions: implications for Chagas disease

    PubMed Central

    Burke, Shoshana; Nagajyothi, Fnu; Thi, Mia M.; Hanani, Menachem; Scherer, Philipp E.; Tanowitz, Herbert B.; Spray, David C.

    2015-01-01

    Adipose tissue serves as a host reservoir for the protozoan Trypanosoma cruzi, the causative organism in Chagas disease. Gap junctions interconnect cells of most tissues, serving to synchronize cell activities including secretion in glandular tissue, and we have previously demonstrated that gap junctions are altered in various tissues and cells infected with T. cruzi. Herein, we examined the gap junction protein connexin 43 (Cx43) expression in infected adipose tissues. Adipose tissue is the largest endocrine organ of the body and is also involved in other physiological functions. In mammals, it is primarily composed of white adipocytes. Although gap junctions are a prominent feature of brown adipocytes, they have not been explored extensively in white adipocytes, especially in the setting of infection. Thus, we examined functional coupling in both white and brown adipocytes in mice. Injection of electrical current or the dye Lucifer Yellow into adipocytes within fat tissue spread to adjacent cells, which was reduced by treatment with agents known to block gap junctions. Moreover, Cx43 was detected in both brown and white fat tissue. At thirty and ninety days post-infection, Cx43 was downregulated in brown adipocytes and upregulated in white adipocytes. Gap junction-mediated intercellular communication likely contributes to hormone secretion and other functions in white adipose tissue and to nonshivering thermogenesis in brown fat, and modulation of the coupling by T. cruzi infection is expected to impact these functions. PMID:25150689

  11. Effect of the acute crowding stress on the rat brown adipose tissue metabolic function.

    PubMed

    Djordjevic, Jelena; Cvijic, Gordana; Petrovic, Natasa; Davidovic, Vukosava

    2005-12-01

    Our previous results have shown that metabolic and thermal stressors influence interscapular brown adipose tissue (IBAT) metabolic activity by increasing oxygen consumption and, consequently, altering the toxic reactive oxygen species (ROS) production and the antioxidative system activity. Since there is not enough evidence about the effect of psychosocial stressors on these processes, we studied the effect of acute crowding stress on the IBAT and hypothalamic monoamine oxidase (MAO) activity as well as IBAT antioxidative enzymes, manganese (MnSOD), copper-zinc superoxide dismutase (CuZnSOD) and catalase (CAT), as the relevant indicators of IBAT metabolic alternations under the stress exposure and the returning of animals to control conditions. The results indicated that acute crowding stress did not change the hypothalamic and IBAT MAO activities, the generation of ROS and, consequently, the IBAT CuZnSOD and CAT activities. However, all three antioxidative enzymes were affected only after the recovery period. It seems that peripheral overheating of rats during acute crowding changes the stress nature, by becoming more thermal than psychosocial and by suppression the hypothalamic efferent pathways involved in the IBAT thermogenesis regulation. However, it seems that returning of the animals to the control conditions after the stress termination causes the reactivation of IBAT thermogenesis with tendency to normalise the body temperature.

  12. Adipose tissue-organotypic culture system as a promising model for studying adipose tissue biology and regeneration

    PubMed Central

    Uchihashi, Kazuyoshi; Aoki, Shigehisa; Sonoda, Emiko; Yamasaki, Fumio; Piao, Meihua; Ootani, Akifumi; Yonemitsu, Nobuhisa; Sugihara, Hajime

    2009-01-01

    Adipose tissue consists of mature adipocytes, preadipocytes and mesenchymal stem cells (MSCs), but a culture system for analyzing their cell types within the tissue has not been established. We have recently developed “adipose tissue-organotypic culture system” that maintains unilocular structure, proliferative ability and functions of mature adipocytes for a long term, using three-dimensional collagen gel culture of the tissue fragments. In this system, both preadipocytes and MSCs regenerate actively at the peripheral zone of the fragments. Our method will open up a new way for studying both multiple cell types within adipose tissue and the cell-based mechanisms of obesity and metabolic syndrome. Thus, it seems to be a promising model for investigating adipose tissue biology and regeneration. In this article, we introduce adipose tissue-organotypic culture, and propose two theories regarding the mechanism of tissue regeneration that occurs specifically at peripheral zone of tissue fragments in vitro. PMID:19794899

  13. Adipose tissue immunity and cancer.

    PubMed

    Catalán, Victoria; Gómez-Ambrosi, Javier; Rodríguez, Amaia; Frühbeck, Gema

    2013-10-02

    Inflammation and altered immune response are important components of obesity and contribute greatly to the promotion of obesity-related metabolic complications, especially cancer development. Adipose tissue expansion is associated with increased infiltration of various types of immune cells from both the innate and adaptive immune systems. Thus, adipocytes and infiltrating immune cells secrete pro-inflammatory adipokines and cytokines providing a microenvironment favorable for tumor growth. Accumulation of B and T cells in adipose tissue precedes macrophage infiltration causing a chronic low-grade inflammation. Phenotypic switching toward M1 macrophages and Th1 T cells constitutes an important mechanism described in the obese state correlating with increased tumor growth risk. Other possible synergic mechanisms causing a dysfunctional adipose tissue include fatty acid-induced inflammation, oxidative stress, endoplasmic reticulum stress, and hypoxia. Recent investigations have started to unravel the intricacy of the cross-talk between tumor cell/immune cell/adipocyte. In this sense, future therapies should take into account the combination of anti-inflammatory approaches that target the tumor microenvironment with more sophisticated and selective anti-tumoral drugs.

  14. Adipose tissue immunity and cancer

    PubMed Central

    Catalán, Victoria; Gómez-Ambrosi, Javier; Rodríguez, Amaia; Frühbeck, Gema

    2013-01-01

    Inflammation and altered immune response are important components of obesity and contribute greatly to the promotion of obesity-related metabolic complications, especially cancer development. Adipose tissue expansion is associated with increased infiltration of various types of immune cells from both the innate and adaptive immune systems. Thus, adipocytes and infiltrating immune cells secrete pro-inflammatory adipokines and cytokines providing a microenvironment favorable for tumor growth. Accumulation of B and T cells in adipose tissue precedes macrophage infiltration causing a chronic low-grade inflammation. Phenotypic switching toward M1 macrophages and Th1 T cells constitutes an important mechanism described in the obese state correlating with increased tumor growth risk. Other possible synergic mechanisms causing a dysfunctional adipose tissue include fatty acid-induced inflammation, oxidative stress, endoplasmic reticulum stress, and hypoxia. Recent investigations have started to unravel the intricacy of the cross-talk between tumor cell/immune cell/adipocyte. In this sense, future therapies should take into account the combination of anti-inflammatory approaches that target the tumor microenvironment with more sophisticated and selective anti-tumoral drugs. PMID:24106481

  15. White adipose tissue: getting nervous.

    PubMed

    Fliers, E; Kreier, F; Voshol, P J; Havekes, L M; Sauerwein, H P; Kalsbeek, A; Buijs, R M; Romijn, J A

    2003-11-01

    Neuroendocrine research has altered the traditional perspective of white adipose tissue (WAT) as a passive store of triglycerides. In addition to fatty acids, WAT produces many hormones and can therefore be designated as a traditional endocrine gland actively participating in the integrative physiology of fuel and energy metabolism, eating behaviour and the regulation of hormone secretion and sensitivity. WAT is controlled by humoral factors, para- and intracrine factors and by neural regulation. Sympathetic nerve fibres innervate WAT and stimulate lipolysis, leading to the release of glycerol and free fatty acids. In addition, recent research in rats has clearly shown a functional parasympathetic innervation of WAT. There appears to be a distinct somatotopy within the parasympathetic nuclei: separate sets of autonomic neurones in the brain stem innervate either the visceral or the subcutaneous fat compartment. We therefore propose that the central nervous system (CNS) plays a major role in the hitherto unexplained regulation of body fat distribution. Parasympathectomy induces insulin resistance with respect to glucose and fatty acid uptake in the innervated fat depot and has selective effects on local hormone synthesis. Thus, the CNS is involved not only in the regulation of hormone production by WAT, but also in its hormone sensitivity. The developments in this research area are likely to increase our insights in the pathogenesis of metabolic disorders such as hypertriglyceridemia, diabetes mellitus type 2 and lipodystrophy syndromes.

  16. Browning and thermogenic programing of adipose tissue.

    PubMed

    Kiefer, Florian W

    2016-08-01

    The view of adipose tissue as solely a fat storing organ has changed significantly over the past two decades with the discoveries of numerous adipocyte-secreted factors, so called adipokines, and their endocrine functions throughout the body. The newest chapter added to this story is the finding that adipose tissue is also a thermogenic organ contributing to energy expenditure through actions of specialized, heat-producing brown or beige adipocytes. In contrast to bone fide brown adipocytes, beige cells develop within white fat depots in response to various stimuli such as prolonged cold exposure, underscoring the great thermogenic plasticity of adipose tissue. The energy dissipating properties of beige and/or brown adipocytes hold great promise as a novel therapeutic concept against obesity and related complications. Hence, identifying the specific thermogenic adipocyte populations in humans and their pathways of activation are key milestones of current metabolism research. Here we will discuss the recent advances in the understanding of the molecular and physiological mechanisms of adipose tissue browning. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Prenatal and lactation nicotine exposure affects morphology and function of brown adipose tissue in male rat offspring.

    PubMed

    Fan, Jie; Ping, Jie; Zhang, Wan-Xia; Rao, Yi-Song; Liu, Han-Xiao; Zhang, Jing; Yan, You-E

    2016-01-01

    The aim of this study was to investigate the effects of prenatal and lactation nicotine exposure on the morphology and function of brown adipose tissue (BAT) in male rat offspring. We conducted a morphological assay and gene expression study of interscapular BAT (iBAT) in male rat offspring. The male offspring from nicotine-exposed dams exhibited higher body weight and iBAT weight. Hematoxylin and eosin staining and transmission electron microscopy showed that iBAT from nicotine-exposed male offspring presented a "whitening" phenotype characterized by lipid droplet accumulation and impaired mitochondria with a randomly oriented and fractured cristae. The expression of the iBAT structure and function-related genes all decreased in nicotine-exposed male offspring. These data indicate that prenatal and lactation nicotine exposure affects morphology and function of iBAT in male rat offspring.

  18. Anatomical locations of human brown adipose tissue: functional relevance and implications in obesity and type 2 diabetes.

    PubMed

    Sacks, Harold; Symonds, Michael E

    2013-06-01

    We will review information about and present hypotheses as to the anatomy of brown adipose tissue (BAT). Why is it located where it is in humans? Its anatomical distribution is likely to confer survival value by protecting critical organs from hypothermia by adaptive thermogenesis. Ultimately, the location and function will be important when considering therapeutic strategies for preventing and treating obesity and type 2 diabetes, in which case successful interventions will need to have a significant effect on BAT function in subjects living in a thermoneutral environment. In view of the diverse locations and potential differences in responsiveness between BAT depots, it is likely that BAT will be shown to have much more subtle and thus previously overlooked functions and regulatory control mechanisms.

  19. Divergent functions of endotrophin on different cell populations in adipose tissue.

    PubMed

    Zhao, Yueshui; Gu, Xue; Zhang, Ningyan; Kolonin, Mikhail G; An, Zhiqiang; Sun, Kai

    2016-12-01

    Endotrophin is a cleavage product of collagen 6 (Col6) in adipose tissue (AT). Previously, we demonstrated that endotrophin serves as a costimulator to trigger fibrosis and inflammation within the unhealthy AT milieu. However, how endotrophin affects lipid storage and breakdown in AT and how different cell types in AT respond to endotrophin stimulation remain unknown. In the current study, by using a doxycycline-inducible mouse model, we observed significant upregulation of adipogenic genes in the white AT (WAT) of endotrophin transgenic mice. We further showed that the mice exhibited inhibited lipolysis and accelerated hypertrophy and hyperplasia in WAT. To investigate the effects of endotrophin in vitro, we incubated different cell types from AT with conditioned medium from endotrophin-overexpressing 293T cells. We found that endotrophin activated multiple pathological pathways in different cell types. Particularly in 3T3-L1 adipocytes, endotrophin triggered a fibrotic program by upregulating collagen genes and promoted abnormal lipid accumulation by downregulating hormone-sensitive lipolysis gene and decreasing HSL phosphorylation levels. In macrophages isolated from WAT, endotrophin stimulated higher expression of the collagen-linking enzyme lysyl oxidase and M1 proinflammatory marker genes. In the stromal vascular fraction isolated from WAT, endotrophin induced upregulation of both profibrotic and proinflammatory genes. In conclusion, our study provides a new perspective on the effect of endotrophin in abnormal lipid accumulation and a mechanistic insight into the roles played by adipocytes and a variety of other cell types in AT in shaping the unhealthy microenvironment upon endotrophin treatment. Copyright © 2016 the American Physiological Society.

  20. Selective suppression of adipose tissue apoE expression impacts systemic metabolic phenotype and adipose tissue inflammation.

    PubMed

    Huang, Zhi H; Reardon, Catherine A; Getz, Godfrey S; Maeda, Nobuyo; Mazzone, Theodore

    2015-02-01

    apoE is a multi-functional protein expressed in several cell types and in several organs. It is highly expressed in adipose tissue, where it is important for modulating adipocyte lipid flux and gene expression in isolated adipocytes. In order to investigate a potential systemic role for apoE that is produced in adipose tissue, mice were generated with selective suppression of adipose tissue apoE expression and normal circulating apoE levels. These mice had less adipose tissue with smaller adipocytes containing fewer lipids, but no change in adipocyte number compared with control mice. Adipocyte TG synthesis in the presence of apoE-containing VLDL was markedly impaired. Adipocyte caveolin and leptin gene expression were reduced, but adiponectin, PGC-1, and CPT-1 gene expression were increased. Mice with selective suppression of adipose tissue apoE had lower fasting lipid, insulin, and glucose levels, and glucose and insulin tolerance tests were consistent with increased insulin sensitivity. Lipid storage in muscle, heart, and liver was significantly reduced. Adipose tissue macrophage inflammatory activation was markedly diminished with suppression of adipose tissue apoE expression. Our results establish a novel effect of adipose tissue apoE expression, distinct from circulating apoE, on systemic substrate metabolism and adipose tissue inflammatory state. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

  1. Adipose tissue biology and cardiomyopathy: translational implications.

    PubMed

    Turer, Aslan T; Hill, Joseph A; Elmquist, Joel K; Scherer, Philipp E

    2012-12-07

    It is epidemiologically established that obesity is frequently associated with the metabolic syndrome and poses an increased risk for the development of type 2 diabetes mellitus and cardiovascular disease. The molecular links that connect the phenomenon of obesity, per se, with insulin resistance and cardiovascular disease are still not fully elucidated. It is increasingly apparent that fully functional adipose tissue can be cardioprotective by reducing lipotoxic effects in other peripheral tissues and by maintaining a healthy balance of critical adipokines, thereby allowing the heart to maintain its full metabolic flexibility. The present review highlights both basic and clinical findings that emphasize the complex interplay of adipose tissue physiology and adipokine-mediated effects on the heart exerted by either direct effects on cardiac myocytes or indirect actions via central mechanisms through sympathetic outflow to the heart.

  2. Structural and functional properties of deep abdominal subcutaneous adipose tissue explain its association with insulin resistance and cardiovascular risk in men.

    PubMed

    Marinou, Kyriakoula; Hodson, Leanne; Vasan, Senthil K; Fielding, Barbara A; Banerjee, Rajarshi; Brismar, Kerstin; Koutsilieris, Michael; Clark, Anne; Neville, Matt J; Karpe, Fredrik

    2014-01-01

    Fat distribution is an important variable explaining metabolic heterogeneity of obesity. Abdominal subcutaneous adipose tissue (SAT) is divided by the Scarpa's fascia into a deep subcutaneous adipose tissue (dSAT) and a superficial subcutaneous adipose tissue (sSAT) layer. This study sought to characterize functional differences between the two SAT layers to explore their relative contribution to metabolic traits and cardiovascular risk (CVR) profile. We recruited 371 Caucasians consecutively from a local random, population-based screening project in Oxford and 25 Asian Indians from the local community. The depth of the SAT layers was determined by ultrasound (US), and adipose tissue (AT) biopsies were performed under US guidance in a subgroup of 43 Caucasians. Visceral adipose tissue (VAT) mass was quantified by dual-energy X-ray absorptiometry scan. Male adiposity in both ethnic groups was characterized by a disproportionate expansion of dSAT, which was strongly correlated with VAT mass. dSAT depth was a strong predictor of global insulin resistance (IR; homeostatic model assessment of IR), liver-specific IR (insulin-like growth factor binding protein-1), and Framingham risk score independently of other measures of adiposity in men. Moreover, dSAT had higher expression of proinflammatory, lipogenic, and lipolytic genes and contained higher proportions of saturated fatty acids. There was increased proportion of small adipocytes in dSAT. SAT is heterogeneous; dSAT expands disproportionally more than sSAT with increasing obesity in Caucasian males (confirmed also in Asian Indians). Its expansion is related to increased CVR independent of other adiposity measures, and it has biological properties suggestive of higher metabolic activity contributing to global IR.

  3. Non-invasive assessments of adipose tissue metabolism in vitro

    PubMed Central

    Abbott, Rosalyn D.; Borowsky, Francis E.; Quinn, Kyle P.; Bernstein, David L.; Georgakoudi, Irene; Kaplan, David L.

    2015-01-01

    Adipose tissue engineering is a diverse area of research where the developed tissues can be used to study normal adipose tissue functions, create disease models in vitro, and replace soft tissue defects in vivo. Increasing attention has been focused on the highly specialized metabolic pathways that regulate energy storage and release in adipose tissues which affect local and systemic outcomes. Non-invasive, dynamic measurement systems are useful to track these metabolic pathways in the same tissue model over time to evaluate long term cell growth, differentiation, and development within tissue engineering constructs. This approach reduces costs and time in comparison to more traditional destructive methods such as biochemical and immunochemistry assays and proteomics assessments. Towards this goal, this review will focus on important metabolic functions of adipose tissues and strategies to evaluate them with noninvasive in vitro methods. Current non-invasive methods, such as measuring key metabolic markers and endogenous contrast imaging will be explored. PMID:26399988

  4. Periprostatic adipose tissue from obese prostate cancer patients promotes tumor and endothelial cell proliferation: a functional and MR imaging pilot study.

    PubMed

    Venkatasubramanian, Palamadai N; Brendler, Charles B; Plunkett, Beth A; Crawford, Susan E; Fitchev, Philip S; Morgan, Gina; Cornwell, Mona L; McGuire, Michael S; Wyrwicz, Alice M; Doll, Jennifer A

    2014-02-01

    Obesity, particularly visceral adiposity, confers a worse prognosis for prostate cancer (PCa) patients, and increasing periprostatic adipose (PPA) tissue thickness or density is positively associated with more aggressive disease. However, the cellular mechanism of this activity remains unclear. Therefore, in this pilot study, we assessed the functional activity of PPA tissue secretions and established a biochemical profile of PPA as compared to subcutaneous adipose (SQA) tissues from lean, overweight and obese PCa patients. Adipose tissues were collected from PCa patients undergoing surgical prostate removal. Tissues were analyzed by histologic and magnetic resonance (MR) techniques. Explant tissue culture secretions were used in proliferation assays on PCa and endothelial cells. PPA secretions obtained from obese patients were significantly more pro-proliferative in both PCa and endothelial cells as compared to PPA obtained from lean or overweight men and SQA tissues. Consistent with this, PPA microvessel density was increased, and the T2 relaxation time was decreased, compared to SQA tissues, and we observed a modest, inverse correlation between the T2 and tumor stage. Moreover, the ratio of unsaturated to saturated fatty acids, obtained using MR spectroscopy, showed a modest, inverse correlation with Gleason score. These pilot data show that PPA stimulates PCa cell proliferation and angiogenesis and that obesity intensifies this activity, thus generating a mechanistic hypothesis to explain the worse prognosis observed in obese PCa patients. Our pilot study also shows that MR technology may be useful in further elucidating the relationship between obesity and PCa progression.

  5. Regulation of systemic energy homeostasis by serotonin in adipose tissues

    PubMed Central

    Oh, Chang-Myung; Namkung, Jun; Go, Younghoon; Shong, Ko Eun; Kim, Kyuho; Kim, Hyeongseok; Park, Bo-Yoon; Lee, Ho Won; Jeon, Yong Hyun; Song, Junghan; Shong, Minho; Yadav, Vijay K.; Karsenty, Gerard; Kajimura, Shingo; Lee, In-Kyu; Park, Sangkyu; Kim, Hail

    2015-01-01

    Central serotonin (5-HT) is an anorexigenic neurotransmitter in the brain. However, accumulating evidence suggests peripheral 5-HT may affect organismal energy homeostasis. Here we show 5-HT regulates white and brown adipose tissue function. Pharmacological inhibition of 5-HT synthesis leads to inhibition of lipogenesis in epididymal white adipose tissue (WAT), induction of browning in inguinal WAT and activation of adaptive thermogenesis in brown adipose tissue (BAT). Mice with inducible Tph1 KO in adipose tissues exhibit a similar phenotype as mice in which 5-HT synthesis is inhibited pharmacologically, suggesting 5-HT has localized effects on adipose tissues. In addition, Htr3a KO mice exhibit increased energy expenditure and reduced weight gain when fed a high-fat diet. Treatment with an Htr2a antagonist reduces lipid accumulation in 3T3-L1 adipocytes. These data suggest important roles for adipocyte-derived 5-HT in controlling energy homeostasis. PMID:25864946

  6. Regulation of systemic energy homeostasis by serotonin in adipose tissues.

    PubMed

    Oh, Chang-Myung; Namkung, Jun; Go, Younghoon; Shong, Ko Eun; Kim, Kyuho; Kim, Hyeongseok; Park, Bo-Yoon; Lee, Ho Won; Jeon, Yong Hyun; Song, Junghan; Shong, Minho; Yadav, Vijay K; Karsenty, Gerard; Kajimura, Shingo; Lee, In-Kyu; Park, Sangkyu; Kim, Hail

    2015-04-13

    Central serotonin (5-HT) is an anorexigenic neurotransmitter in the brain. However, accumulating evidence suggests peripheral 5-HT may affect organismal energy homeostasis. Here we show 5-HT regulates white and brown adipose tissue function. Pharmacological inhibition of 5-HT synthesis leads to inhibition of lipogenesis in epididymal white adipose tissue (WAT), induction of browning in inguinal WAT and activation of adaptive thermogenesis in brown adipose tissue (BAT). Mice with inducible Tph1 KO in adipose tissues exhibit a similar phenotype as mice in which 5-HT synthesis is inhibited pharmacologically, suggesting 5-HT has localized effects on adipose tissues. In addition, Htr3a KO mice exhibit increased energy expenditure and reduced weight gain when fed a high-fat diet. Treatment with an Htr2a antagonist reduces lipid accumulation in 3T3-L1 adipocytes. These data suggest important roles for adipocyte-derived 5-HT in controlling energy homeostasis.

  7. Inverse regulation of inflammation and mitochondrial function in adipose tissue defines extreme insulin sensitivity in morbidly obese patients.

    PubMed

    Qatanani, Mohammed; Tan, Yejun; Dobrin, Radu; Greenawalt, Danielle M; Hu, Guanghui; Zhao, Wenqing; Olefsky, Jerrold M; Sears, Dorothy D; Kaplan, Lee M; Kemp, Daniel M

    2013-03-01

    Obesity is associated with insulin resistance, a major risk factor for type 2 diabetes and cardiovascular disease. However, not all obese individuals are insulin resistant, which confounds our understanding of the mechanistic link between these conditions. We conducted transcriptome analyses on 835 obese subjects with mean BMI of 48.8, on which we have previously reported genetic associations of gene expression. Here, we selected ~320 nondiabetic (HbA(1c) <7.0) subjects and further stratified the cohort into insulin-resistant versus insulin-sensitive subgroups based on homeostasis model assessment-insulin resistance. An unsupervised informatics analysis revealed that immune response and inflammation-related genes were significantly downregulated in the omental adipose tissue of obese individuals with extreme insulin sensitivity and, to a much lesser extent, in subcutaneous adipose tissue. In contrast, genes related to β-oxidation and the citric acid cycle were relatively overexpressed in adipose of insulin-sensitive patients. These observations were verified by querying an independent cohort of our published dataset of 37 subjects whose subcutaneous adipose tissue was sampled before and after treatment with thiazolidinediones. Whereas the immune response and inflammation pathway genes were downregulated by thiazolidinedione treatment, β-oxidation and citric acid cycle genes were upregulated. This work highlights the critical role that omental adipose inflammatory pathways might play in the pathophysiology of insulin resistance, independent of body weight.

  8. Brown adipose tissue and bone

    PubMed Central

    Lidell, M E; Enerbäck, S

    2015-01-01

    Brown adipose tissue (BAT) is capable of transforming chemically stored energy, in the form of triglycerides, into heat. Recent studies have shown that metabolically active BAT is present in a large proportion of adult humans, where its activity correlates with a favorable metabolic status. Hence, the tissue is now regarded as an interesting target for therapies against obesity and associated diseases such as type 2 diabetes, the hypothesis being that an induction of BAT would be beneficial for these disease states. Apart from the association between BAT activity and a healthier metabolic status, later studies have also shown a positive correlation between BAT volume and both bone cross-sectional area and bone mineral density, suggesting that BAT might stimulate bone anabolism. The aim of this review is to give the reader a brief overview of the BAT research field and to summarize and discuss recent findings regarding BAT being a potential player in bone metabolism. PMID:27152171

  9. Marrow adipose tissue: trimming the fat

    PubMed Central

    Burr, Aaron A.; Horowitz, Mark C.; MacDougald, Ormond A

    2016-01-01

    Marrow adipose tissue (MAT) is a unique fat depot, located in the skeleton, that has the potential to contribute to both local and systemic metabolic processes. In this review we highlight several recent conceptual developments pertaining to the origin and function of MAT adipocytes; consider the relationship of MAT to beige, brown, and white adipose depots; explore MAT expansion and turnover in humans and rodents; and discuss future directions for MAT research in the context of endocrine function and metabolic disease. MAT has the potential to exert both local and systemic effects on metabolic homeostasis, skeletal remodeling, hematopoiesis, and development of bone metastases. The diversity of these functions highlights the breadth of MAT’s potential impact on health and disease. PMID:27094502

  10. Ginsenoside Rg1 and platelet-rich fibrin enhance human breast adipose-derived stem cell function for soft tissue regeneration.

    PubMed

    Xu, Fang-Tian; Liang, Zhi-Jie; Li, Hong-Mian; Peng, Qi-Liu; Huang, Min-Hong; Li, De Quan; Liang, Yi-Dan; Chi, Gang-Yi; Li, De Hui; Yu, Bing-Chao; Huang, Ji-Rong

    2016-06-07

    Adipose-derived stem cells (ASCs) can be used to repair soft tissue defects, wounds, burns, and scars and to regenerate various damaged tissues. The cell differentiation capacity of ASCs is crucial for engineered adipose tissue regeneration in reconstructive and plastic surgery. We previously reported that ginsenoside Rg1 (G-Rg1 or Rg1) promotes proliferation and differentiation of ASCs in vitro and in vivio. Here we show that both G-Rg1 and platelet-rich fibrin (PRF) improve the proliferation, differentiation, and soft tissue regeneration capacity of human breast adipose-derived stem cells (HBASCs) on collagen type I sponge scaffolds in vitro and in vivo. Three months after transplantation, tissue wet weight, adipocyte number, intracellular lipid, microvessel density, and gene and protein expression of VEGF, HIF-1α, and PPARγ were higher in both G-Rg1- and PRF-treated HBASCs than in control grafts. More extensive new adipose tissue formation was evident after treatment with G-Rg1 or PRF. In summary, G-Rg1 and/or PRF co-administration improves the function of HBASCs for soft tissue regeneration engineering.

  11. Ginsenoside Rg1 and platelet-rich fibrin enhance human breast adipose-derived stem cells function for soft tissue regeneration

    PubMed Central

    Li, Hong-Mian; Peng, Qi-Liu; Huang, Min-Hong; Li, De-Quan; Liang, Yi-Dan; Chi, Gang-Yi; Li, De-Hui; Yu, Bing-Chao; Huang, Ji-Rong

    2016-01-01

    Adipose-derived stem cells (ASCs) can be used to repair soft tissue defects, wounds, burns, and scars and to regenerate various damaged tissues. The cell differentiation capacity of ASCs is crucial for engineered adipose tissue regeneration in reconstructive and plastic surgery. We previously reported that ginsenoside Rg1 (G-Rg1 or Rg1) promotes proliferation and differentiation of ASCs in vitro and in vivio. Here we show that both G-Rg1 and platelet-rich fibrin (PRF) improve the proliferation, differentiation, and soft tissue regeneration capacity of human breast adipose-derived stem cells (HBASCs) on collagen type I sponge scaffolds in vitro and in vivo. Three months after transplantation, tissue wet weight, adipocyte number, intracellular lipid, microvessel density, and gene and protein expression of VEGF, HIF-1α, and PPARγ were higher in both G-Rg1- and PRF-treated HBASCs than in control grafts. More extensive new adipose tissue formation was evident after treatment with G-Rg1 or PRF. In summary, G-Rg1 and/or PRF co-administration improves the function of HBASCs for soft tissue regeneration engineering. PMID:27191987

  12. White to beige conversion in PDE3B KO adipose tissue through activation of AMPK signaling and mitochondrial function

    PubMed Central

    Chung, Youn Wook; Ahmad, Faiyaz; Tang, Yan; Hockman, Steven C.; Kee, Hyun Jung; Berger, Karin; Guirguis, Emilia; Choi, Young Hun; Schimel, Dan M.; Aponte, Angel M.; Park, Sunhee; Degerman, Eva; Manganiello, Vincent C.

    2017-01-01

    Understanding mechanisms by which a population of beige adipocytes is increased in white adipose tissue (WAT) reflects a potential strategy in the fight against obesity and diabetes. Cyclic adenosine monophosphate (cAMP) is very important in the development of the beige phenotype and activation of its thermogenic program. To study effects of cyclic nucleotides on energy homeostatic mechanisms, mice were generated by targeted inactivation of cyclic nucleotide phosphodiesterase 3b (Pde3b) gene, which encodes PDE3B, an enzyme that catalyzes hydrolysis of cAMP and cGMP and is highly expressed in tissues that regulate energy homeostasis, including adipose tissue, liver, and pancreas. In epididymal white adipose tissue (eWAT) of PDE3B KO mice on a SvJ129 background, cAMP/protein kinase A (PKA) and AMP-activated protein kinase (AMPK) signaling pathways are activated, resulting in “browning” phenotype, with a smaller increases in body weight under high-fat diet, smaller fat deposits, increased β-oxidation of fatty acids (FAO) and oxygen consumption. Results reported here suggest that PDE3B and/or its downstream signaling partners might be important regulators of energy metabolism in adipose tissue, and potential therapeutic targets for treating obesity, diabetes and their associated metabolic disorders. PMID:28084425

  13. Common SIRT1 variants modify the effect of abdominal adipose tissue on aging-related lung function decline.

    PubMed

    Curjuric, Ivan; Imboden, Medea; Bridevaux, Pierre-Olivier; Gerbase, Margaret W; Haun, Margot; Keidel, Dirk; Kumar, Ashish; Pons, Marco; Rochat, Thierry; Schikowski, Tamara; Schindler, Christian; von Eckardstein, Arnold; Kronenberg, Florian; Probst-Hensch, Nicole M

    2016-06-01

    Lung function is an independent predictor of mortality and serves as an aging marker in never smokers. The protein sirtuin-1 of gene SIRT1 has profound anti-inflammatory effects and regulates metabolic pathways. Its suggested longevity effects on lower organisms remain poorly studied in humans. In 1132 never smokers of the population-based SAPALDIA cohort, we investigated associations between single nucleotide polymorphisms (SNPs; rs730821, rs10997868, rs10823116) of SIRT1 and aging-related lung function decline over 11 years in terms of change in forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio, and forced expiratory flow between 25 and 75 % of FVC (FEF25-75) using multiple linear regression models. Interactions between the SIRT1 SNPs and adiposity parameters (body mass index (BMI), its change and weight gain) were tested by including multiplicative interaction terms into the models. SIRT1 polymorphisms exhibited no main effects, but modified the association between obesity measures and FEV1/FVC and FEF25-75 decline (p = 0.009-0.046). Per risk allele, FEV1/FVC decline was accelerated up to -0.5 % (95 % CI -1.0 to 0 %) and -0.7 % (-1.3 to -0.2 %) over interquartile range increases in BMI (2.4 kg/m(2)) or weight (6.5 kg), respectively. For FEF25-75 decline, corresponding estimates were -57 mL/s (-117 to 4 mL/s) and -76 mL/s (-1429 to -9 mL/s). Interactions were not present in participants with genetically lowered C-reactive protein concentrations. Genetic variation in SIRT1 might therefore affect lung function and human longevity by modifying subclinical inflammation arising from abdominal adipose tissue.

  14. Understanding androgen action in adipose tissue.

    PubMed

    O'Reilly, Michael W; House, Philip J; Tomlinson, Jeremy W

    2014-09-01

    Androgens play an important role in regulation of body fat distribution in humans. They exert direct effects on adipocyte differentiation in a depot-specific manner, via the androgen receptor (AR), leading to modulation of adipocyte size and fat compartment expansion. Androgens also impact directly on key adipocyte functions including insulin signalling, lipid metabolism, fatty acid uptake and adipokine production. Androgen excess and deficiency have implications for metabolic health in both males and females, and these metabolic effects may be mediated through adipose tissue via effects on fat distribution, adipocyte function and lipolysis. Research into the field of androgen metabolism in human and animal adipose tissue has produced inconsistent results; it is important to take into account the sex-, depot- and organism-specific effects of androgens in fat. In general, studies point towards a stimulatory effect on lipolysis, with impairment of adipocyte differentiation, insulin signalling and adipokine generation. Observed effects are frequently gender-specific. Adipose tissue is an important organ of pre-receptor androgen metabolism, through which local androgen availability is rigorously controlled. Adipose androgen exposure is tightly controlled by isoenzymes of AKR1C, 5α-reductase and others, but regulation of the balance between generation and irreversible inactivation remains poorly understood. In particular, AKR1C2 and AKR1C3 are crucial in the regulation of local androgen bioavailability within adipose tissue. These isoforms control the balance between activation of androstenedione (A) to testosterone (T) by the 17β-hydroxysteroid dehydrogenase activity (17β-HSD) of AKR1C3, or inactivation of 5α-dihydrotestosterone (DHT) to 5α-androstane-3α,17β-diol by the 3α-hydroxysteroid dehydrogenase (3α-HSD) activity of AKR1C2. Most studies suggest that androgen inactivation is the predominant reaction in fat, particularly in the abdominal subcutaneous (SC

  15. Trypanosoma brucei parasites occupy and functionally adapt to the adipose tissue in mice

    SciTech Connect

    Trindade, Sandra; Rijo-Ferreira, Filipa; Carvalho, Tania; Pinto-Neves, Daniel; Guegan, Fabien; Aresta-Branco, Francisco; Bento, Fabio; Young, Simon A.; Pinto, Andreia; Van Den Abbeele, Jan; Ribeiro, Ruy M.; Dias, Sergio; Smith, Terry K.; Figueiredo, Luisa M.

    2016-05-26

    Trypanosoma brucei is an extracellular parasite that causes sleeping sickness. In mammalian hosts, trypanosomes are thought to exist in two major niches: early in infection, they populate the blood; later, they breach the blood-brain barrier. Working with a well-established mouse model, we discovered that adipose tissue constitutes a third major reservoir for T. brucei. Parasites from adipose tissue, here termed adipose tissue forms (ATFs), can replicate and were capable of infecting a naive animal. ATFs were transcriptionally distinct from bloodstream forms, and the genes upregulated included putative fatty acid β-oxidation enzymes. Consistent with this, ATFs were able to utilize exogenous myristate and form β-oxidation intermediates, suggesting that ATF parasites can use fatty acids as an external carbon source. Lastly, these findings identify the adipose tissue as a niche for T. brucei during its mammalian life cycle and could potentially explain the weight loss associated with sleeping sickness.

  16. Effects of Berberine on Adipose Tissues and Kidney Function in 3T3-L1 Cells and Spontaneously Hypertensive Rats.

    PubMed

    Kishimoto, Aya; Dong, Shi-Fen; Negishi, Hiroko; Yasui, Naomi; Sun, Jian-Ning; Ikeda, Katsumi

    2015-09-01

    We aimed to investigate the effect of berberine on adipose tissues, as well as its effect on renal injury in 3T3-L1 cells and spontaneously hypertensive rats. 3T3-L1 cells were cultured and treated with berberine (5-20 pM) from days 3 to 8. Berberine added to the cultured medium could significantly down-regulate transcription factors, including CCAAT/enhancer binding protein β, CCAAT/enhancer binding protein a, and peroxisome pro liferator-activated receptor y, and suppress peroxisome proliferator-activated receptor target genes, such as adipocyte fatty acid binding protein and fatty acid synthase, and inhibit 3T3-Ll fibroblast differentiation to adipocytes. Male spontaneously hypertensive rats received either 150 mg/day of berberine or saline orally for 8 weeks. Compared with the control, berberine-treated rats exhibited significant reductions in body weight gain (p < 0.05), as well as retroperitoneal and mesenteric adipose tissues (p < 0.05). Berberine-treated rats significantly decreased urinary albumin excretion, a marker of renal injury (p < 0.05). Long-term treatment with berberine decreased the adipose tissues weight and attenuated renal injury in spontaneously hypertensive rats. Based on these results, berberine has an important role in regulating adipose tissues. These results suggest the protective effect of berberine on metabolic syndrome related diseases, such as renal injury.

  17. Is adipose tissue metabolically different at different sites?

    PubMed

    Gil, Angel; Olza, Josune; Gil-Campos, Mercedes; Gomez-Llorente, Carolina; Aguilera, Concepción M

    2011-09-01

    This review focuses on metabolic differences of adipose tissue at different sites of the body, with emphasis in pediatrics. Adipose tissue is composed of various cell types, which include adipocytes and other cells of the stromal vascular fraction such as preadipocytes, blood cells, endothelial cells and macrophages. Mammals have two main types of adipose tissue: white adipose tissue (WAT), and brown adipose tissue (BAT), each of which possesses unique cell autonomous properties. WAT and BAT differ at the functional, as well as the morphological and molecular levels. WAT accumulates surplus energy mainly in the form of triacylglycerols and BAT dissipates energy directly as heat. Recently, functional BAT in humans has been located in the neck, supraclavicular, mediastinal and interscapular areas. WAT is distributed throughout the body in the form of two major types: subcutaneous adipose tissue (SWAT) and the intra-abdominal visceral adipose tissue (VWAT). VWAT tissue is associated with insulin resistance, diabetes mellitus, dyslipidaemia, hypertension, atherosclerosis, hepatic steatosis, and overall mortality whereas SWAT and BAT have intrinsic beneficial metabolic properties. Subcutaneous and visceral adipocytes derive from different progenitor cells that exhibit a different gene expression pattern. SWAT responds better to the antilipolytic effects of insulin and other hormones, secrets more adiponectin and less inflammatory cytokines, and is differentially affected by molecules involved in signal transduction as well as drugs compared with VWAT. Current research is investigating various approaches of BAT and SWAT transplantation, including new sources of adipocyte progenitors. This may be important for the potential treatment of childhood obesity.

  18. Adiponectin and interleukin-6, but not adipose tissue, are associated with worse neurocognitive function in HIV-infected men.

    PubMed

    Lake, Jordan E; Vo, Quynh T; Jacobson, Lisa P; Sacktor, Ned; Miller, Eric N; Post, Wendy S; Becker, James T; Palella, Frank J; Ragin, Ann; Martin, Eileen; Munro, Cynthia A; Brown, Todd T

    2015-01-01

    Generalized obesity has been associated with cognitive decline, a process potentially mediated by adipocytokines. The effects of regional adipose tissue (AT) on cognition, however, are not well understood. We explored cross-sectional relationships between regional AT, adipocytokines, inflammatory markers and neuropsychological (NP) test scores among HIV+ and HIV- men enrolled in the Multicenter AIDS Cohort Study. Visceral, subcutaneous abdominal and subcutaneous thigh AT areas were quantified by computed tomography (CT). NP tests (Trail Making Test parts A and B, and Symbol-Digit Modalities) obtained within 2 years of CT screened for psychomotor speed and executive function. Adiponectin, leptin, interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hs-CRP) were measured. Of 509 HIV+ and 271 HIV- participants, HIV+ men (98% on antiretroviral therapy, 81% HIV-1 RNA<50 copies/ml) had lower median subcutaneous AT and adiponectin levels and higher hs-CRP levels, but visceral AT, body mass index, IL-6 and NP scores did not vary by HIV serostatus. In multivariable analysis, older age, ≤ high school education and African American race, but not AT area or site, were associated with worse NP test scores among all participants. In HIV+ only, higher adiponectin and IL-6 were associated with worse cognitive function independent of AT area. No HIV-specific factors were associated with NP test scores. Demographic factors were associated with NP test performance, but regional adiposity was not. In HIV+ only, higher adiponectin and IL-6 were associated with worse NP test scores, supporting a role for chronic inflammation and adipocytokine imbalance in neurocognitive decline in HIV+ persons.

  19. Bone Marrow Adipose Tissue: To Be or Not To Be a Typical Adipose Tissue?

    PubMed Central

    Hardouin, Pierre; Rharass, Tareck; Lucas, Stéphanie

    2016-01-01

    Bone marrow adipose tissue (BMAT) emerges as a distinct fat depot whose importance has been proved in the bone–fat interaction. Indeed, it is well recognized that adipokines and free fatty acids released by adipocytes can directly or indirectly interfere with cells of bone remodeling or hematopoiesis. In pathological states, such as osteoporosis, each of adipose tissues – subcutaneous white adipose tissue (WAT), visceral WAT, brown adipose tissue (BAT), and BMAT – is differently associated with bone mineral density (BMD) variations. However, compared with the other fat depots, BMAT displays striking features that makes it a substantial actor in bone alterations. BMAT quantity is well associated with BMD loss in aging, menopause, and other metabolic conditions, such as anorexia nervosa. Consequently, BMAT is sensed as a relevant marker of a compromised bone integrity. However, analyses of BMAT development in metabolic diseases (obesity and diabetes) are scarce and should be, thus, more systematically addressed to better apprehend the bone modifications in that pathophysiological contexts. Moreover, bone marrow (BM) adipogenesis occurs throughout the whole life at different rates. Following an ordered spatiotemporal expansion, BMAT has turned to be a heterogeneous fat depot whose adipocytes diverge in their phenotype and their response to stimuli according to their location in bone and BM. In vitro, in vivo, and clinical studies point to a detrimental role of BM adipocytes (BMAs) throughout the release of paracrine factors that modulate osteoblast and/or osteoclast formation and function. However, the anatomical dissemination and the difficulties to access BMAs still hamper our understanding of the relative contribution of BMAT secretions compared with those of peripheral adipose tissues. A further characterization of the phenotype and the functional regulation of BMAs are ever more required. Based on currently available data and comparison with other fat

  20. Cellularity of adipose tissue in fetal pig.

    PubMed

    Desnoyers, F; Pascal, G; Etienne, M; Vodovar, N

    1980-03-01

    Adipose tissue cellularity was studied in the 85-day-old Large-White pig fetus. The aim of this work was to count the adipose cells of forming tissue in an animal species which could be a possible model for studying adipose tissue in humans. Using a morphometric method with electron microscopy, mean triglyceride volume per cell was determined independently of mean cell volume. This method is suitable for counting adipose cells in the early stage of differentiation whatever their size and lipid inclusion volume. Site-by-site dissection of adipose tissue was not feasible in the 85-day old fetus and adipose cell number was computed by dividing total carcass triglyceride volume by mean triglyceride volume per cell. The carcass triglyceride seemed to originate only from adipose cells. The mean total carcass triglyceride volume per fetus (1.84 g) was low but, owing to the low mean triglyceride volume per cell (180.28 microns3), the adipose cell number (11.15 X 10(9)) was relatively important, as it represented about 27% of the extramuscular adipose cell number in the Large-White adult pig (41 X 10(9)).

  1. Thyroid hormone status defines brown adipose tissue activity and browning of white adipose tissues in mice

    PubMed Central

    Weiner, Juliane; Kranz, Mathias; Klöting, Nora; Kunath, Anne; Steinhoff, Karen; Rijntjes, Eddy; Köhrle, Josef; Zeisig, Vilia; Hankir, Mohammed; Gebhardt, Claudia; Deuther-Conrad, Winnie; Heiker, John T.; Kralisch, Susan; Stumvoll, Michael; Blüher, Matthias; Sabri, Osama; Hesse, Swen; Brust, Peter; Tönjes, Anke; Krause, Kerstin

    2016-01-01

    The present study aimed to determine the effect of thyroid hormone dysfunction on brown adipose tissue activity and white adipose tissue browning in mice. Twenty randomized female C57BL/6NTac mice per treatment group housed at room temperature were rendered hypothyroid or hyperthyroid. In-vivo small animal 18F-FDG PET/MRI was performed to determine the effects of hypo- and hyperthyroidism on BAT mass and BAT activity. Ex-vivo14C-acetate loading assay and assessment of thermogenic gene and protein expression permitted analysis of oxidative and thermogenic capacities of WAT and BAT of eu-, hyper and hypothyroid mice. 18F-FDG PET/MRI revealed a lack of brown adipose tissue activity in hypothyroid mice, whereas hyperthyroid mice displayed increased BAT mass alongside enhanced 18F-FDG uptake. In white adipose tissue of both, hyper- and hypothyroid mice, we found a significant induction of thermogenic genes together with multilocular adipocytes expressing UCP1. Taken together, these results suggest that both the hyperthyroid and hypothyroid state stimulate WAT thermogenesis most likely as a consequence of enhanced adrenergic signaling or compensation for impaired BAT function, respectively. PMID:27941950

  2. Thyroid hormone status defines brown adipose tissue activity and browning of white adipose tissues in mice.

    PubMed

    Weiner, Juliane; Kranz, Mathias; Klöting, Nora; Kunath, Anne; Steinhoff, Karen; Rijntjes, Eddy; Köhrle, Josef; Zeisig, Vilia; Hankir, Mohammed; Gebhardt, Claudia; Deuther-Conrad, Winnie; Heiker, John T; Kralisch, Susan; Stumvoll, Michael; Blüher, Matthias; Sabri, Osama; Hesse, Swen; Brust, Peter; Tönjes, Anke; Krause, Kerstin

    2016-12-12

    The present study aimed to determine the effect of thyroid hormone dysfunction on brown adipose tissue activity and white adipose tissue browning in mice. Twenty randomized female C57BL/6NTac mice per treatment group housed at room temperature were rendered hypothyroid or hyperthyroid. In-vivo small animal (18)F-FDG PET/MRI was performed to determine the effects of hypo- and hyperthyroidism on BAT mass and BAT activity. Ex-vivo(14)C-acetate loading assay and assessment of thermogenic gene and protein expression permitted analysis of oxidative and thermogenic capacities of WAT and BAT of eu-, hyper and hypothyroid mice. (18)F-FDG PET/MRI revealed a lack of brown adipose tissue activity in hypothyroid mice, whereas hyperthyroid mice displayed increased BAT mass alongside enhanced (18)F-FDG uptake. In white adipose tissue of both, hyper- and hypothyroid mice, we found a significant induction of thermogenic genes together with multilocular adipocytes expressing UCP1. Taken together, these results suggest that both the hyperthyroid and hypothyroid state stimulate WAT thermogenesis most likely as a consequence of enhanced adrenergic signaling or compensation for impaired BAT function, respectively.

  3. Diets high in monounsaturated and polyunsaturated fatty acids decrease fatty acid synthase protein levels in adipose tissue but do not alter other markers of adipose function and inflammation in diet-induced obese rats.

    PubMed

    Enns, Jennifer E; Hanke, Danielle; Park, Angela; Zahradka, Peter; Taylor, Carla G

    2014-01-01

    This study investigates the effects of monounsaturated and polyunsaturated fatty acids from different fat sources (High Oleic Canola, Canola, Canola-Flaxseed (3:1 blend), Safflower, or Soybean Oil, or a Lard-based diet) on adipose tissue function and markers of inflammation in Obese Prone rats fed high-fat (55% energy) diets for 12 weeks. Adipose tissue fatty acid composition reflected the dietary fatty acid profiles. Protein levels of fatty acid synthase, but not mRNA levels, were lower in adipose tissue of all groups compared to the Lard group. Adiponectin and fatty acid receptors GPR41 and GPR43 protein levels were also altered, but other metabolic and inflammatory mediators in adipose tissue and serum were unchanged among groups. Overall, rats fed vegetable oil- or lard-based high-fat diets appear to be largely resistant to major phenotypic changes when the dietary fat composition is altered, providing little support for the importance of specific fatty acid profiles in the context of a high-fat diet. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Maternal high-fat diet during lactation impairs thermogenic function of brown adipose tissue in offspring mice

    PubMed Central

    Liang, Xingwei; Yang, Qiyuan; Zhang, Lupei; Maricelli, Joseph W; Rodgers, Buel D.; Zhu, Mei-Jun; Du, Min

    2016-01-01

    Maternal obesity and high-fat diet (HFD) predisposes offspring to obesity and metabolic diseases. Due to uncoupling, brown adipose tissue (BAT) dissipates energy via heat generation, mitigating obesity and diabetes. The lactation stage is a manageable period for improving the health of offspring of obese mothers, but the impact of maternal HFD during lactation on offspring BAT function is unknown. To determine, female mice were fed either a control or HFD during lactation. At weaning, HFD offspring gained more body weight and had greater body fat mass compared to the control, and these differences maintained into adulthood, which correlated with glucose intolerance and insulin resistance in HFD offspring. Adaptive thermogenesis of BAT was impaired in HFD offspring at weaning. In adulthood, HFD offspring BAT had lower Ucp1 expression and thermogenic activity. Mechanistically, maternal HFD feeding during lactation elevated peripheral serotonin, which decreased the sensitivity of BAT to sympathetic β3-adrenergic signaling. Importantly, early postnatal metformin administration decreased serotonin concentration and ameliorated the impairment of offspring BAT due to maternal HFD. Our data suggest that attenuation of BAT thermogenic function may be a key mechanism linking maternal HFD during lactation to persisted metabolic disorder in the offspring. PMID:27686741

  5. Impaired Left Ventricular Diastolic Functions and Thickened Epicardial Adipose Tissue in Rheumatoid Arthritis Patients is Correlated with DAS-28 Score

    PubMed Central

    Alpaydın, Sertac; Buyukterzi, Zafer; Akkurt, Halil Ekrem; Yılmaz, Halim

    2017-01-01

    Background Rheumatoid arthritis (RA) is a chronic inflammatory disease that is known to be associated with high cardiovascular (CV) morbidity and mortality. In this study, we aimed to demonstrate whether RA disease activity reflected with disease activity score-28 (DAS-28) had an impact on left ventricular diastolic functions and epicardial adipose tissue (EAT) thickness in RA patients with no traditional CV risk factors. Methods In this retrospective study, 41 patients newly diagnosed with RA were included. In addition to medical history, detailed physical examination findings and laboratory tests, left ventricular systolic and diastolic functions, chamber dimensions, and EAT thickness were evaluated with transthoracic echocardiography in the study population. Results This study included 41 subjects with a median age of 45 years (38.00-55.50), of which 29.27% were male. In the binomial logistic regression analysis, DAS-28 score was found to be an independent associate of diastolic dysfunction, Additionally, DAS-28 was found to be independently associated with EAT thickness. Conclusions Patients with high DAS-28 score should be evaluated thoroughly for CV disease, and patients should undergo advanced diagnostic studies as required and receive appropriate treatment. PMID:28344422

  6. Biochemistry of adipose tissue: an endocrine organ.

    PubMed

    Coelho, Marisa; Oliveira, Teresa; Fernandes, Ruben

    2013-04-20

    Adipose tissue is no longer considered to be an inert tissue that stores fat. This tissue is capable of expanding to accommodate increased lipids through hypertrophy of existing adipocytes and by initiating differentiation of pre-adipocytes. Adipose tissue metabolism exerts an impact on whole-body metabolism. As an endocrine organ, adipose tissue is responsible for the synthesis and secretion of several hormones. These are active in a range of processes, such as control of nutritional intake (leptin, angiotensin), control of sensitivity to insulin and inflammatory process mediators (tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), resistin, visfatin, adiponectin, among others) and pathways (plasminogen activator inhibitor 1 (PAI-1) and acylation stimulating protein (ASP) for example). This paper reviews some of the biochemical and metabolic aspects of adipose tissue and its relationship to inflammatory disease and insulin resistance.

  7. Biochemistry of adipose tissue: an endocrine organ

    PubMed Central

    Coelho, Marisa; Oliveira, Teresa

    2013-01-01

    Adipose tissue is no longer considered to be an inert tissue that stores fat. This tissue is capable of expanding to accommodate increased lipids through hypertrophy of existing adipocytes and by initiating differentiation of pre-adipocytes. Adipose tissue metabolism exerts an impact on whole-body metabolism. As an endocrine organ, adipose tissue is responsible for the synthesis and secretion of several hormones. These are active in a range of processes, such as control of nutritional intake (leptin, angiotensin), control of sensitivity to insulin and inflammatory process mediators (tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), resistin, visfatin, adiponectin, among others) and pathways (plasminogen activator inhibitor 1 (PAI-1) and acylation stimulating protein (ASP) for example). This paper reviews some of the biochemical and metabolic aspects of adipose tissue and its relationship to inflammatory disease and insulin resistance. PMID:23671428

  8. Molecular pathways regulating the formation of brown-like adipocytes in white adipose tissue.

    PubMed

    Fu, Jianfei; Li, Zhen; Zhang, Huiqin; Mao, Yushan; Wang, Anshi; Wang, Xin; Zou, Zuquan; Zhang, Xiaohong

    2015-07-01

    Adipose tissue is functionally composed of brown adipose tissue and white adipose tissue. The unique thermogenic capacity of brown adipose tissue results from expression of uncoupling protein 1 in the mitochondrial inner membrane. On the basis of recent findings that adult humans have functionally active brown adipose tissue, it is now recognized as playing a much more important role in human metabolism than was previously thought. More importantly, brown-like adipocytes can be recruited in white adipose tissue upon environmental stimulation and pharmacologic treatment, and this change is associated with increased energy expenditure, contributing to a lean and healthy phenotype. Thus, the promotion of brown-like adipocyte development in white adipose tissue offers novel possibilities for the development of therapeutic strategies to combat obesity and related metabolic diseases. In this review, we summarize recent advances in understanding the molecular mechanisms involved in the recruitment of brown-like adipocyte in white adipose tissue.

  9. Proline oxidase-adipose triglyceride lipase pathway restrains adipose cell death and tissue inflammation.

    PubMed

    Lettieri Barbato, D; Aquilano, K; Baldelli, S; Cannata, S M; Bernardini, S; Rotilio, G; Ciriolo, M R

    2014-01-01

    The nutrient-sensing lipolytic enzyme adipose triglyceride lipase (ATGL) has a key role in adipose tissue function, and alterations in its activity have been implicated in many age-related metabolic disorders. In adipose tissue reduced blood vessel density is related to hypoxia state, cell death and inflammation. Here we demonstrate that adipocytes of poorly vascularized enlarged visceral adipose tissue (i.e. adipose tissue of old mice) suffer from limited nutrient delivery. In particular, nutrient starvation elicits increased activity of mitochondrial proline oxidase/dehydrogenase (POX/PRODH) that is causal in triggering a ROS-dependent induction of ATGL. We demonstrate that ATGL promotes the expression of genes related to mitochondrial oxidative metabolism (peroxisome proliferator-activated receptor-α, peroxisome proliferator-activated receptor-γ coactivator-1α), thus setting a metabolic switch towards fat utilization that supplies energy to starved adipocytes and prevents cell death, as well as adipose tissue inflammation. Taken together, these results identify ATGL as a stress resistance mediator in adipocytes, restraining visceral adipose tissue dysfunction typical of age-related metabolic disorders.

  10. Brown adipose tissue, thermogenesis, angiogenesis: pathophysiological aspects.

    PubMed

    Honek, Jennifer; Lim, Sharon; Fischer, Carina; Iwamoto, Hideki; Seki, Takahiro; Cao, Yihai

    2014-07-01

    The number of obese and overweight individuals is globally rising, and obesity-associated disorders such as type 2 diabetes, cardiovascular disease and certain types of cancer are among the most common causes of death. While white adipose tissue is the key player in the storage of energy, active brown adipose tissue expends energy due to its thermogenic capacity. Expanding and activating brown adipose tissue using pharmacological approaches therefore might offer an attractive possibility for therapeutic intervention to counteract obesity and its consequences for metabolic health.

  11. Sexual Dimorphism in the Age-Induced Insulin Resistance, Liver Steatosis, and Adipose Tissue Function in Rats.

    PubMed

    Garcia-Carrizo, Francisco; Priego, Teresa; Szostaczuk, Nara; Palou, Andreu; Picó, Catalina

    2017-01-01

    Age-linked metabolic disturbances, such as liver steatosis and insulin resistance, show greater prevalence in men than in women. Thus, our aim was to analyze these sex-related differences in male and female Wistar rats (aged 26 days and 3, 7, and 14 months), and to assess their potential relationship with alterations in the capacity of adipose tissue expansion and the dysregulation of the main adipokines produced by the adipose tissue, leptin and adiponectin. Adiposity-related parameters, blood parameters, the expression of genes related to expandability and inflammation (WAT), lipid metabolism (liver), and leptin and insulin signaling (both tissues) were measured. In females, adiposity index and WAT DNA content gradually increased with age, whereas males peaked at 7 months. A similar sex-dependent pattern was observed for leptin expression in WAT, while Mest expression levels decreased with age in males but not in females. Females also showed increased expression of the proliferation marker PCNA in the inguinal WAT compared to males. In males, leptin/adiponectin ratio greatly increased from 7 to 14 months in a more acute manner than in females, along with an increase in HOMA-IR index and hepatic triacylglyceride content, while no changes were observed in females. In liver, 14-month-old males displayed decreased mRNA levels of Insr, Ampkα2, and Cpt1a compared with levels at 7 months. Males also showed decreased mRNA levels of Obrb (both tissues), and increased expression levels of Cd68 and Emr1 (WAT) with age. In conclusion, females are more protected from age-related metabolic disturbances, such as insulin resistance, hepatic lipid deposition, and WAT inflammation compared to males. This may be related to their greater capacity for WAT expansion-reflected by a greater Mest/leptin mRNA ratio-and to their ability to maintain adiponectin levels and preserve leptin sensitivity with aging.

  12. Sexual Dimorphism in the Age-Induced Insulin Resistance, Liver Steatosis, and Adipose Tissue Function in Rats

    PubMed Central

    Garcia-Carrizo, Francisco; Priego, Teresa; Szostaczuk, Nara; Palou, Andreu; Picó, Catalina

    2017-01-01

    Age-linked metabolic disturbances, such as liver steatosis and insulin resistance, show greater prevalence in men than in women. Thus, our aim was to analyze these sex-related differences in male and female Wistar rats (aged 26 days and 3, 7, and 14 months), and to assess their potential relationship with alterations in the capacity of adipose tissue expansion and the dysregulation of the main adipokines produced by the adipose tissue, leptin and adiponectin. Adiposity-related parameters, blood parameters, the expression of genes related to expandability and inflammation (WAT), lipid metabolism (liver), and leptin and insulin signaling (both tissues) were measured. In females, adiposity index and WAT DNA content gradually increased with age, whereas males peaked at 7 months. A similar sex-dependent pattern was observed for leptin expression in WAT, while Mest expression levels decreased with age in males but not in females. Females also showed increased expression of the proliferation marker PCNA in the inguinal WAT compared to males. In males, leptin/adiponectin ratio greatly increased from 7 to 14 months in a more acute manner than in females, along with an increase in HOMA-IR index and hepatic triacylglyceride content, while no changes were observed in females. In liver, 14-month-old males displayed decreased mRNA levels of Insr, Ampkα2, and Cpt1a compared with levels at 7 months. Males also showed decreased mRNA levels of Obrb (both tissues), and increased expression levels of Cd68 and Emr1 (WAT) with age. In conclusion, females are more protected from age-related metabolic disturbances, such as insulin resistance, hepatic lipid deposition, and WAT inflammation compared to males. This may be related to their greater capacity for WAT expansion—reflected by a greater Mest/leptin mRNA ratio—and to their ability to maintain adiponectin levels and preserve leptin sensitivity with aging. PMID:28744221

  13. New Physiological Aspects of Brown Adipose Tissue.

    PubMed

    Trayhurn, Paul; Arch, Jonathan R S

    2014-12-01

    Brown adipose tissue is specialised for the generation of heat by non-shivering mechanisms. In rodents, the tissue plays a role in energy balance and the development of obesity, as well as in thermoregulation. Studies using fluorodeoxyglucose positron emission tomography (FDG-PET), together with the identification of uncoupling protein-1, have provided definitive evidence that brown adipose tissue is present in adult humans. Brown fat activity is stimulated by cold exposure, declines with age and is inversely proportional to BMI. This has led to renewed interest in the tissue as a therapeutic target for the treatment of obesity. Brown adipose tissue also plays a role in glucose disposal and triglyceride clearance, implicating it in the metabolic syndrome. A potential mechanism for increasing thermogenesis is by the 'browning' of white adipose depots through the recruitment of the recently identified third type of adipocyte - the brite (or beige) fat cell.

  14. Adipose Tissue Remodeling: Its Role in Energy Metabolism and Metabolic Disorders

    PubMed Central

    Choe, Sung Sik; Huh, Jin Young; Hwang, In Jae; Kim, Jong In; Kim, Jae Bum

    2016-01-01

    The adipose tissue is a central metabolic organ in the regulation of whole-body energy homeostasis. The white adipose tissue functions as a key energy reservoir for other organs, whereas the brown adipose tissue accumulates lipids for cold-induced adaptive thermogenesis. Adipose tissues secrete various hormones, cytokines, and metabolites (termed as adipokines) that control systemic energy balance by regulating appetitive signals from the central nerve system as well as metabolic activity in peripheral tissues. In response to changes in the nutritional status, the adipose tissue undergoes dynamic remodeling, including quantitative and qualitative alterations in adipose tissue-resident cells. A growing body of evidence indicates that adipose tissue remodeling in obesity is closely associated with adipose tissue function. Changes in the number and size of the adipocytes affect the microenvironment of expanded fat tissues, accompanied by alterations in adipokine secretion, adipocyte death, local hypoxia, and fatty acid fluxes. Concurrently, stromal vascular cells in the adipose tissue, including immune cells, are involved in numerous adaptive processes, such as dead adipocyte clearance, adipogenesis, and angiogenesis, all of which are dysregulated in obese adipose tissue remodeling. Chronic overnutrition triggers uncontrolled inflammatory responses, leading to systemic low-grade inflammation and metabolic disorders, such as insulin resistance. This review will discuss current mechanistic understandings of adipose tissue remodeling processes in adaptive energy homeostasis and pathological remodeling of adipose tissue in connection with immune response. PMID:27148161

  15. Lack of Adipocyte AMPK Exacerbates Insulin Resistance and Hepatic Steatosis through Brown and Beige Adipose Tissue Function.

    PubMed

    Mottillo, Emilio P; Desjardins, Eric M; Crane, Justin D; Smith, Brennan K; Green, Alex E; Ducommun, Serge; Henriksen, Tora I; Rebalka, Irena A; Razi, Aida; Sakamoto, Kei; Scheele, Camilla; Kemp, Bruce E; Hawke, Thomas J; Ortega, Joaquin; Granneman, James G; Steinberg, Gregory R

    2016-07-12

    Brown (BAT) and white (WAT) adipose tissues play distinct roles in maintaining whole-body energy homeostasis, and their dysfunction can contribute to non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes. The AMP-activated protein kinase (AMPK) is a cellular energy sensor, but its role in regulating BAT and WAT metabolism is unclear. We generated an inducible model for deletion of the two AMPK β subunits in adipocytes (iβ1β2AKO) and found that iβ1β2AKO mice were cold intolerant and resistant to β-adrenergic activation of BAT and beiging of WAT. BAT from iβ1β2AKO mice had impairments in mitochondrial structure, function, and markers of mitophagy. In response to a high-fat diet, iβ1β2AKO mice more rapidly developed liver steatosis as well as glucose and insulin intolerance. Thus, AMPK in adipocytes is vital for maintaining mitochondrial integrity, responding to pharmacological agents and thermal stress, and protecting against nutrient-overload-induced NAFLD and insulin resistance. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. PPARγ2 Pro12Ala polymorphism is associated with improved lipoprotein lipase functioning in adipose tissue of insulin resistant obese women.

    PubMed

    López-Alarcón, Mardia; Rodríguez-Cruz, Maricela; Vital-Reyes, Victor Saúl; Zavala-Ortega, María Isabel; Hinojosa-Cruz, Juan Carlos; Canizales-Quinteros, Samuel; Fernández, José

    2012-12-15

    Lipoprotein lipase (LPL) plays a pivotal role in lipid metabolism, contributes to metabolic disorders related to insulin action and body weight regulation, and is influenced by inflammation. The Pro12Ala polymorphism of the peroxisome proliferator-activated receptor (PPAR)γ2 gene seems to influence LPL functioning, but its role in obesity and insulin resistance status, which usually coexist in the clinical setting, has not been explored. Our aim was to analyze the association of obesity and insulin resistance with adipose LPL activity and expression, and the influence of the PPARγ2 Pro12Ala polymorphism. A cross-sectional study was conducted in 58 reproductive-age women who underwent elective abdominal surgery. Free-fatty acids, glucose, insulin, and selected adipokines were measured in fasting blood samples. DNA was isolated and the polymorphism genotyped. Biopsies of abdominal subcutaneous adipose tissue obtained during surgery were used to determine enzymatic LPL activity and expression; and expression of selected cytokines. Overweight/obese women presented lower LPL activity (P=0.022) and higher circulating TNF-α (P=0.020) than controls. Insulin resistant women also showed borderline lower LPL activity than non-resistant (P=0.052), but adiposity and inflammatory molecules were comparable. Nevertheless, LPL activity was higher in Pro12Ala carriers than in non-carriers after adjusting for obesity, insulin resistance and inflammation. Likewise, adipose LPL expression was increased in carriers while expression of cytokines was decreased. Our data suggest that insulin resistance is associated with low adipose LPL activity independently of obesity, but the PPARγ2 Pro12Ala polymorphism seems to protect the LPL functioning of obese insulin resistant women, likely through regulating inflammation in adipose tissue. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Intermuscular and intramuscular adipose tissues: Bad vs. good adipose tissues

    PubMed Central

    Hausman, Gary J; Basu, Urmila; Du, Min; Fernyhough-Culver, Melinda; Dodson, Michael V

    2014-01-01

    Human studies of the influence of aging and other factors on intermuscular fat (INTMF) were reviewed. Intermuscular fat increased with weight loss, weight gain, or with no weight change with age in humans. An increase in INTMF represents a similar threat to type 2 diabetes and insulin resistance as does visceral adipose tissue (VAT). Studies of INTMF in animals covered topics such as quantitative deposition and genetic relationships with other fat depots. The relationship between leanness and higher proportions of INTMF fat in pigs was not observed in human studies and was not corroborated by other pig studies. In humans, changes in muscle mass, strength and quality are associated with INTMF accretion with aging. Gene expression profiling and intrinsic methylation differences in pigs demonstrated that INTMF and VAT are primarily associated with inflammatory and immune processes. It seems that in the pig and humans, INTMF and VAT share a similar pattern of distribution and a similar association of components dictating insulin sensitivity. Studies on intramuscular (IM) adipocyte development in meat animals were reviewed. Gene expression analysis and genetic analysis have identified candidate genes involved in IM adipocyte development. Intramuscular (IM) adipocyte development in human muscle is only seen during aging and some pathological circumstance. Several genetic links between human and meat animal adipogenesis have been identified. In pigs, the Lipin1 and Lipin 2 gene have strong genetic effects on IM accumulation. Lipin1 deficiency results in immature adipocyte development in human lipodystrophy. In humans, overexpression of Perilipin 2 (PLIN2) facilitates intramyocellular lipid accretion whereas in pigs PLIN2 gene expression is associated with IM deposition. Lipins and perilipins may influence intramuscular lipid regardless of species. PMID:26317048

  18. Adipose tissue-derived stromal cells (ADSC) express oligodendrocyte and myelin markers, but they do not function as oligodendrocytes.

    PubMed

    Vellosillo, Lara; Muñoz, Maria Paz; Paíno, Carlos Luis

    2017-06-15

    Mesenchymal cells cultured from the vasculo-stromal fraction of adipose tissue (ADSC) show adult stem cell characteristics and several groups have claimed generating neural cells from them. However, we have observed that many markers commonly used for the identification of neural cells are spontaneously expressed by ADSC in culture. In the present study, we have examined the expression of characteristic oligodendrocyte molecules in cultured ADSC, aiming to test if myelinating cells could be generated from accessible non-neural adult tissues. In basal growth conditions, rat ADSC spontaneously expressed CNPase, MBP, MOG, protein zero, GAP43, Sox10, and Olig2, as shown by immunocytrochemistry and western blot. A small population of cultured ADSC expressed membrane galactocerebroside (O1 antibody), but no cell stained with O4 antibody. RT-PCR analyses showed the expression of CNPase, MBP, DM20, and low levels of Olig2, Sox10, and Sox2 mRNA by rat ADSC. When rat ADSC were treated with combinations of factors commonly used in neural-inducing media (retinoic acid, dbcAMP, EGF, basic FGF, NT3, and/or PDGF), the number of O1-positive cells changed, but in no case, mRNA expression of Sox10 and Olig2 transcription factors approached CNS oligodendrocyte levels. In co-culture with rat dorsal root ganglion neurons, no sign of axonal myelination by rat ADSC was observed. These studies show that the expression of oligodendrocyte traits by cultured ADSC is not a proof of functional competence as oligodendroglia and suggest that in culture conditions, ADSC acquire intermediate, uncommitted phenotypes.

  19. Regulation of adipose tissue lipolysis revisited.

    PubMed

    Bézaire, Véronic; Langin, Dominique

    2009-11-01

    Human obesity and its complications are an increasing burden in developed and underdeveloped countries. Adipose tissue mass and the mechanisms that control it are central to elucidating the aetiology of obesity and insulin resistance. Over the past 15 years tremendous progress has been made in several avenues relating to adipose tissue. Knowledge of the lipolytic machinery has grown with the identification of new lipases, cofactors and interactions between proteins and lipids that are central to the regulation of basal and stimulated lipolysis. The dated idea of an inert lipid droplet has been appropriately revamped to that of a dynamic and highly-structured organelle that in itself offers regulatory control over lipolysis. The present review provides an overview of the numerous partners and pathways involved in adipose tissue lipolysis and their interaction under various metabolic states. Integration of these findings into whole adipose tissue metabolism and its systemic effects is also presented in the context of inflammation and insulin resistance.

  20. Deletion of inducible nitric-oxide synthase in leptin-deficient mice improves brown adipose tissue function.

    PubMed

    Becerril, Sara; Rodríguez, Amaia; Catalán, Victoria; Sáinz, Neira; Ramírez, Beatriz; Collantes, María; Peñuelas, Iván; Gómez-Ambrosi, Javier; Frühbeck, Gema

    2010-06-04

    Leptin and nitric oxide (NO) on their own participate in the control of non-shivering thermogenesis. However, the functional interplay between both factors in this process has not been explored so far. Therefore, the aim of the present study was to analyze the impact of the absence of the inducible NO synthase (iNOS) gene in the regulation of energy balance in ob/ob mice. Double knockout (DBKO) mice simultaneously lacking the ob and iNOS genes were generated, and the expression of molecules involved in the control of brown fat cell function was analyzed by real-time PCR, western-blot and immunohistochemistry. Twelve week-old DBKO mice exhibited reduced body weight (p<0.05), decreased amounts of total fat pads (p<0.05), lower food efficiency rates (p<0.05) and higher rectal temperature (p<0.05) than ob/ob mice. Ablation of iNOS also improved the carbohydrate and lipid metabolism of ob/ob mice. DBKO showed a marked reduction in the size of brown adipocytes compared to ob/ob mutants. In this sense, in comparison to ob/ob mice, DBKO rodents showed an increase in the expression of PR domain containing 16 (Prdm16), a transcriptional regulator of brown adipogenesis. Moreover, iNOS deletion enhanced the expression of mitochondria-related proteins, such as peroxisome proliferator-activated receptor gamma coactivator-1 alpha (Pgc-1alpha), sirtuin-1 (Sirt-1) and sirtuin-3 (Sirt-3). Accordingly, mitochondrial uncoupling proteins 1 and 3 (Ucp-1 and Ucp-3) were upregulated in brown adipose tissue (BAT) of DBKO mice as compared to ob/ob rodents. Ablation of iNOS improved the energy balance of ob/ob mice by decreasing food efficiency through an increase in thermogenesis. These effects may be mediated, in part, through the recovery of the BAT phenotype and brown fat cell function improvement.

  1. Deletion of Inducible Nitric-Oxide Synthase in Leptin-Deficient Mice Improves Brown Adipose Tissue Function

    PubMed Central

    Becerril, Sara; Rodríguez, Amaia; Catalán, Victoria; Sáinz, Neira; Ramírez, Beatriz; Collantes, María; Peñuelas, Iván; Gómez-Ambrosi, Javier; Frühbeck, Gema

    2010-01-01

    Background Leptin and nitric oxide (NO) on their own participate in the control of non-shivering thermogenesis. However, the functional interplay between both factors in this process has not been explored so far. Therefore, the aim of the present study was to analyze the impact of the absence of the inducible NO synthase (iNOS) gene in the regulation of energy balance in ob/ob mice. Methods and Findings Double knockout (DBKO) mice simultaneously lacking the ob and iNOS genes were generated, and the expression of molecules involved in the control of brown fat cell function was analyzed by real-time PCR, western-blot and immunohistochemistry. Twelve week-old DBKO mice exhibited reduced body weight (p<0.05), decreased amounts of total fat pads (p<0.05), lower food efficiency rates (p<0.05) and higher rectal temperature (p<0.05) than ob/ob mice. Ablation of iNOS also improved the carbohydrate and lipid metabolism of ob/ob mice. DBKO showed a marked reduction in the size of brown adipocytes compared to ob/ob mutants. In this sense, in comparison to ob/ob mice, DBKO rodents showed an increase in the expression of PR domain containing 16 (Prdm16), a transcriptional regulator of brown adipogenesis. Moreover, iNOS deletion enhanced the expression of mitochondria-related proteins, such as peroxisome proliferator-activated receptor γ coactivator-1 α (Pgc-1α), sirtuin-1 (Sirt-1) and sirtuin-3 (Sirt-3). Accordingly, mitochondrial uncoupling proteins 1 and 3 (Ucp-1 and Ucp-3) were upregulated in brown adipose tissue (BAT) of DBKO mice as compared to ob/ob rodents. Conclusion Ablation of iNOS improved the energy balance of ob/ob mice by decreasing food efficiency through an increase in thermogenesis. These effects may be mediated, in part, through the recovery of the BAT phenotype and brown fat cell function improvement. PMID:20532036

  2. Adipose-derived stem cells and periodontal tissue engineering.

    PubMed

    Tobita, Morikuni; Mizuno, Hiroshi

    2013-01-01

    Innovative developments in the multidisciplinary field of tissue engineering have yielded various implementation strategies and the possibility of functional tissue regeneration. Technologic advances in the combination of stem cells, biomaterials, and growth factors have created unique opportunities to fabricate tissues in vivo and in vitro. The therapeutic potential of human multipotent mesenchymal stem cells (MSCs), which are harvested from bone marrow and adipose tissue, has generated increasing interest in a wide variety of biomedical disciplines. These cells can differentiate into a variety of tissue types, including bone, cartilage, fat, and nerve tissue. Adipose-derived stem cells have some advantages compared with other sources of stem cells, most notably that a large number of cells can be easily and quickly isolated from adipose tissue. In current clinical therapy for periodontal tissue regeneration, several methods have been developed and applied either alone or in combination, such as enamel matrix proteins, guided tissue regeneration, autologous/allogeneic/xenogeneic bone grafts, and growth factors. However, there are various limitations and shortcomings for periodontal tissue regeneration using current methods. Recently, periodontal tissue regeneration using MSCs has been examined in some animal models. This method has potential in the regeneration of functional periodontal tissues because the various secreted growth factors from MSCs might not only promote the regeneration of periodontal tissue but also encourage neovascularization of the damaged tissues. Adipose-derived stem cells are especially effective for neovascularization compared with other MSC sources. In this review, the possibility and potential of adipose-derived stem cells for regenerative medicine are introduced. Of particular interest, periodontal tissue regeneration with adipose-derived stem cells is discussed.

  3. The role of dietary fat in adipose tissue metabolism.

    PubMed

    Fernández-Quintela, Alfredo; Churruca, Itziar; Portillo, Maria Puy

    2007-10-01

    Energy intake and expenditure tend on average to remain adjusted to each other in order to maintain a stable body weight, which is only likely to be sustained if the fuel mix oxidised is equivalent to the nutrient content of the diet. Whereas protein and carbohydrate degradation and oxidation are closely adjusted to their intakes, fat balance regulation is less precise and that fat is more likely to be stored than oxidised. It has been demonstrated that dietary fatty acids have an influence not only on the fatty acid composition of membrane phospholipids, thus modulating several metabolic processes that take place in the adipocyte, but also on the composition and the quantity of different fatty acids in adipose tissue. Moreover, dietary fatty acids also modulate eicosanoid presence, which have hormone-like activities in lipid metabolism regulation in adipose tissue. Until recently, the adipocyte has been considered to be no more than a passive tissue for storage of excess energy. However, there is now compelling evidence that adipocytes have a role as endocrine secretory cells. Some of the adipokines produced by adipose tissue, such as leptin and adiponectin, act on adipose tissue in an autocrine/paracrine manner to regulate adipocyte metabolism. Furthermore, dietary fatty acids may influence the expression of adipokines. The nutrients are among the most influential of the environmental factors that determine the way adipose tissue genes are expressed by functioning as regulators of gene transcription. Therefore, not only dietary fat amount but also dietary fat composition influence adipose tissue metabolism.

  4. [Kidney, adipose tissue, adipocytes--what's new?].

    PubMed

    Lafontan, Max

    2011-04-01

    Increased evidence suggests that obesity-related glomerulopathy and chronic kidney diseases should be identified as isolated complications of obesity. It is questioned if the numerous adipose tissue productions could play a role in the initiation/maintenance of such kidney diseases. This review will provide a sum-up of recent advances on fat cell metabolism and adipose tissue physiology. The adipose tissue behaves as an endocrine organ with multiple activities. It is secreting hormones (leptin, adiponectin, apelin) and numerous factors with autocrine, paracrine and systemic effects. These secretions are coming from adipocytes themselves or from cells present in the stroma-vascular fraction of the adipose tissue. When expanding, the adipose tissue of the obese is infiltrated by immune cells such as macrophages and lymphocytes; the role of which is not fully clarified. An attempt will be done to delineate if alterations of lipid storage/fatty acid release or of the secretion potencies of adipose tissue could contribute to kidney lipotoxicity and other chronic kidney diseases described in the obese. Copyright © 2010 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.

  5. Impact of Maternal Melatonin Suppression on Amount and Functionality of Brown Adipose Tissue (BAT) in the Newborn Sheep

    PubMed Central

    Seron-Ferre, Maria; Reynolds, Henry; Mendez, Natalia Andrea; Mondaca, Mauricio; Valenzuela, Francisco; Ebensperger, Renato; Valenzuela, Guillermo J.; Herrera, Emilio A.; Llanos, Anibal J.; Torres-Farfan, Claudia

    2015-01-01

    In human and sheep newborns, brown adipose tissue (BAT) accrued during fetal development is used for newborn thermogenesis. Here, we explored the role of maternal melatonin during gestation on the amount and functionality of BAT in the neonate. We studied BAT from six lambs gestated by ewes exposed to constant light from 63% gestation until delivery to suppress melatonin (LL), six lambs gestated by ewes exposed to LL but receiving daily oral melatonin (12 mg at 1700 h, LL + Mel) and another six control lambs gestated by ewes maintained in 12 h light:12 h dark (LD). Lambs were instrumented at 2 days of age. At 4–6 days of age, they were exposed to 24°C (thermal neutrality conditions) for 1 h, 4°C for 1 h, and 24°C for 1 h. Afterward, lambs were euthanized and BAT was dissected for mRNA measurement, histology, and ex vivo experiments. LL newborns had lower central BAT and skin temperature under thermal neutrality and at 4°C, and higher plasma norepinephrine concentration than LD newborns. In response to 4°C, they had a pronounced decrease in skin temperature and did not increase plasma glycerol. BAT weight in LL newborns was about half of that of LD newborns. Ex vivo, BAT from LL newborns showed increased basal lipolysis and did not respond to NE. In addition, expression of adipogenic/thermogenic genes (UCP1, ADBR3, PPARγ, PPARα, PGC1α, C/EBPβ, and perilipin) and of the clock genes Bmal1, Clock, and Per2 was increased. Remarkably, the effects observed in LL newborns were absent in LL + Mel newborns. Thus, our results support that maternal melatonin during gestation is important in determining amount and normal functionality of BAT in the neonate. PMID:25610428

  6. Impact of Maternal Melatonin Suppression on Amount and Functionality of Brown Adipose Tissue (BAT) in the Newborn Sheep.

    PubMed

    Seron-Ferre, Maria; Reynolds, Henry; Mendez, Natalia Andrea; Mondaca, Mauricio; Valenzuela, Francisco; Ebensperger, Renato; Valenzuela, Guillermo J; Herrera, Emilio A; Llanos, Anibal J; Torres-Farfan, Claudia

    2014-01-01

    In human and sheep newborns, brown adipose tissue (BAT) accrued during fetal development is used for newborn thermogenesis. Here, we explored the role of maternal melatonin during gestation on the amount and functionality of BAT in the neonate. We studied BAT from six lambs gestated by ewes exposed to constant light from 63% gestation until delivery to suppress melatonin (LL), six lambs gestated by ewes exposed to LL but receiving daily oral melatonin (12 mg at 1700 h, LL + Mel) and another six control lambs gestated by ewes maintained in 12 h light:12 h dark (LD). Lambs were instrumented at 2 days of age. At 4-6 days of age, they were exposed to 24°C (thermal neutrality conditions) for 1 h, 4°C for 1 h, and 24°C for 1 h. Afterward, lambs were euthanized and BAT was dissected for mRNA measurement, histology, and ex vivo experiments. LL newborns had lower central BAT and skin temperature under thermal neutrality and at 4°C, and higher plasma norepinephrine concentration than LD newborns. In response to 4°C, they had a pronounced decrease in skin temperature and did not increase plasma glycerol. BAT weight in LL newborns was about half of that of LD newborns. Ex vivo, BAT from LL newborns showed increased basal lipolysis and did not respond to NE. In addition, expression of adipogenic/thermogenic genes (UCP1, ADBR3, PPARγ, PPARα, PGC1α, C/EBPβ, and perilipin) and of the clock genes Bmal1, Clock, and Per2 was increased. Remarkably, the effects observed in LL newborns were absent in LL + Mel newborns. Thus, our results support that maternal melatonin during gestation is important in determining amount and normal functionality of BAT in the neonate.

  7. A peptide probe for targeted brown adipose tissue imaging.

    PubMed

    Azhdarinia, Ali; Daquinag, Alexes C; Tseng, Chieh; Ghosh, Sukhen C; Ghosh, Pradip; Amaya-Manzanares, Felipe; Sevick-Muraca, Eva; Kolonin, Mikhail G

    2013-01-01

    The presence of brown adipose tissue responsible for thermogenic energy dissipation has been revealed in adult humans and has high clinical importance. Owing to limitations of current methods for brown adipose tissue detection, analysing the abundance and localization of brown adipose tissue in the body has remained challenging. Here we screen a combinatorial peptide library in mice and characterize a peptide (with the sequence CPATAERPC) that selectively binds to the vascular endothelium of brown adipose tissue, but not of intraperitoneal white adipose tissue. We show that in addition to brown adipose tissue, this peptide probe also recognizes the vasculature of brown adipose tissue-like depots of subcutaneous white adipose tissue. Our results indicate that the CPATAERPC peptide localizes to brown adipose tissue even in the absence of sympathetic nervous system stimulation. Finally, we demonstrate that this probe can be used to identify brown adipose tissue depots in mice by whole-body near-infrared fluorescence imaging.

  8. Functional and anatomical characterization of brown adipose tissue in heart failure with blood oxygen level dependent magnetic resonance.

    PubMed

    Panagia, Marcello; Chen, Yin-Ching Iris; Chen, Howard H; Ernande, Laura; Chen, Chan; Chao, Wei; Kwong, Kenneth; Scherrer-Crosbie, Marielle; Sosnovik, David E

    2016-07-01

    Recent studies have suggested that brown adipose tissue (BAT) plays an important role in obesity, insulin resistance and heart failure. The characterization of BAT in vivo, however, has been challenging. No technique to comprehensively image BAT anatomy and function has been described. Moreover, the impact on BAT of the neuroendocrine activation seen in heart failure has only recently begun to be evaluated in vivo. The aim of this study was to use MRI to characterize the impact of heart failure on the morphology and function of BAT. Mice subjected to permanent ligation of the left coronary artery were imaged with MRI 6 weeks later. T2 weighted MRI of BAT volume and blood oxygen level dependent MRI of BAT function were performed. T2 * maps of BAT were obtained at multiple time points before and after administration of the β3 adrenergic agonist CL 316 243 (CL). Blood flow to BAT was studied after CL injection using the flow alternating inversion recovery (FAIR) approach. Excised BAT tissue was analyzed for lipid droplet content and for uncoupling protein 1 (UCP1) mRNA expression. BAT volume was significantly lower in heart failure (51 ± 1 mm(3) versus 65 ± 3 mm(3) ; p < 0.05), and characterized by a reduction in lipid globules and a fourfold increase in UCP1 mRNA (p < 0.05). CL injection increased BAT T2 * in healthy animals but not in mice with heart failure (24 ± 4% versus 6 ± 2%; p < 0.01), consistent with an increase in flow in control BAT. This was confirmed by a significant difference in the FAIR response in BAT in control and heart failure mice. Heart failure results in the chronic activation of BAT, decreased BAT lipid stores and decreased BAT volume, and it is associated with a marked decrease in ability to respond to acute physiological stimuli. This may have important implications for substrate utilization and overall metabolic homeostasis in heart failure. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016

  9. Hypertrophy and/or Hyperplasia: Dynamics of Adipose Tissue Growth.

    PubMed

    Jo, Junghyo; Gavrilova, Oksana; Pack, Stephanie; Jou, William; Mullen, Shawn; Sumner, Anne E; Cushman, Samuel W; Periwal, Vipul

    2009-03-01

    Adipose tissue grows by two mechanisms: hyperplasia (cell number increase) and hypertrophy (cell size increase). Genetics and diet affect the relative contributions of these two mechanisms to the growth of adipose tissue in obesity. In this study, the size distributions of epididymal adipose cells from two mouse strains, obesity-resistant FVB/N and obesity-prone C57BL/6, were measured after 2, 4, and 12 weeks under regular and high-fat feeding conditions. The total cell number in the epididymal fat pad was estimated from the fat pad mass and the normalized cell-size distribution. The cell number and volume-weighted mean cell size increase as a function of fat pad mass. To address adipose tissue growth precisely, we developed a mathematical model describing the evolution of the adipose cell-size distributions as a function of the increasing fat pad mass, instead of the increasing chronological time. Our model describes the recruitment of new adipose cells and their subsequent development in different strains, and with different diet regimens, with common mechanisms, but with diet- and genetics-dependent model parameters. Compared to the FVB/N strain, the C57BL/6 strain has greater recruitment of small adipose cells. Hyperplasia is enhanced by high-fat diet in a strain-dependent way, suggesting a synergistic interaction between genetics and diet. Moreover, high-fat feeding increases the rate of adipose cell size growth, independent of strain, reflecting the increase in calories requiring storage. Additionally, high-fat diet leads to a dramatic spreading of the size distribution of adipose cells in both strains; this implies an increase in size fluctuations of adipose cells through lipid turnover.

  10. Gene Expression Signature in Adipose Tissue of Acromegaly Patients.

    PubMed

    Hochberg, Irit; Tran, Quynh T; Barkan, Ariel L; Saltiel, Alan R; Chandler, William F; Bridges, Dave

    2015-01-01

    To study the effect of chronic excess growth hormone on adipose tissue, we performed RNA sequencing in adipose tissue biopsies from patients with acromegaly (n = 7) or non-functioning pituitary adenomas (n = 11). The patients underwent clinical and metabolic profiling including assessment of HOMA-IR. Explants of adipose tissue were assayed ex vivo for lipolysis and ceramide levels. Patients with acromegaly had higher glucose, higher insulin levels and higher HOMA-IR score. We observed several previously reported transcriptional changes (IGF1, IGFBP3, CISH, SOCS2) that are known to be induced by GH/IGF-1 in liver but are also induced in adipose tissue. We also identified several novel transcriptional changes, some of which may be important for GH/IGF responses (PTPN3 and PTPN4) and the effects of acromegaly on growth and proliferation. Several differentially expressed transcripts may be important in GH/IGF-1-induced metabolic changes. Specifically, induction of LPL, ABHD5, and NRIP1 can contribute to enhanced lipolysis and may explain the elevated adipose tissue lipolysis in acromegalic patients. Higher expression of TCF7L2 and the fatty acid desaturases FADS1, FADS2 and SCD could contribute to insulin resistance. Ceramides were not different between the two groups. In summary, we have identified the acromegaly gene expression signature in human adipose tissue. The significance of altered expression of specific transcripts will enhance our understanding of the metabolic and proliferative changes associated with acromegaly.

  11. Adipose Tissue Oxygenation in Obesity: A Matter of Cardiovascular Risk?

    PubMed

    Landini, Linda; Honka, Miikka-Juhani; Ferrannini, Ele; Nuutila, Pirjo

    2016-01-01

    Obesity, a chronic low-grade inflammation disorder characterized by an expansion in adipose tissue mass, is rapidly expanding worldwide leading to an increase in the incidence of comorbidities such as insulin resistance, type 2 diabetes and cardiovascular diseases. This has led to a renewed interest in the adipose tissue function, historically considered as a passive fat storage. It is now well established that adipose tissue is an organ with an active role in production and release of a variety of molecules called adipocytokines. Dysregulated production of adipocytokines seems to be responsible for the pathogenesis of insulin resistance and type 2 diabetes; however, the mechanisms are still unclear. Hypoxia, that occurs when adipocytes expand in obesity, has been proposed as a possible cause of adipose tissue inflammation. On the other hand, recent studies have shown that adipose tissue oxygen tension was actually higher (hyperoxia) than normal and associated with insulin resistance in obesity, despite a reduction in blood flow. This might be explained by the role of mitochondrial oxygen consumption. Hence, further studies are needed to understand the role of adipose tissue oxygenation and perfusion in obesity to assess pathophysiology and novel opportunities for treating the diseases.

  12. Gene Expression Signature in Adipose Tissue of Acromegaly Patients

    PubMed Central

    Hochberg, Irit; Tran, Quynh T.; Barkan, Ariel L.; Saltiel, Alan R.; Chandler, William F.; Bridges, Dave

    2015-01-01

    To study the effect of chronic excess growth hormone on adipose tissue, we performed RNA sequencing in adipose tissue biopsies from patients with acromegaly (n = 7) or non-functioning pituitary adenomas (n = 11). The patients underwent clinical and metabolic profiling including assessment of HOMA-IR. Explants of adipose tissue were assayed ex vivo for lipolysis and ceramide levels. Patients with acromegaly had higher glucose, higher insulin levels and higher HOMA-IR score. We observed several previously reported transcriptional changes (IGF1, IGFBP3, CISH, SOCS2) that are known to be induced by GH/IGF-1 in liver but are also induced in adipose tissue. We also identified several novel transcriptional changes, some of which may be important for GH/IGF responses (PTPN3 and PTPN4) and the effects of acromegaly on growth and proliferation. Several differentially expressed transcripts may be important in GH/IGF-1-induced metabolic changes. Specifically, induction of LPL, ABHD5, and NRIP1 can contribute to enhanced lipolysis and may explain the elevated adipose tissue lipolysis in acromegalic patients. Higher expression of TCF7L2 and the fatty acid desaturases FADS1, FADS2 and SCD could contribute to insulin resistance. Ceramides were not different between the two groups. In summary, we have identified the acromegaly gene expression signature in human adipose tissue. The significance of altered expression of specific transcripts will enhance our understanding of the metabolic and proliferative changes associated with acromegaly. PMID:26087292

  13. Brown Adipose Tissue in Cetacean Blubber

    PubMed Central

    Hashimoto, Osamu; Ohtsuki, Hirofumi; Kakizaki, Takehiko; Amou, Kento; Sato, Ryo; Doi, Satoru; Kobayashi, Sara; Matsuda, Ayaka; Sugiyama, Makoto; Funaba, Masayuki; Matsuishi, Takashi; Terasawa, Fumio; Shindo, Junji; Endo, Hideki

    2015-01-01

    Brown adipose tissue (BAT) plays an important role in thermoregulation in species living in cold environments, given heat can be generated from its chemical energy reserves. Here we investigate the existence of BAT in blubber in four species of delphinoid cetacean, the Pacific white-sided and bottlenose dolphins, Lagenorhynchus obliquidens and Tursiops truncates, and Dall’s and harbour porpoises, Phocoenoides dalli and Phocoena phocoena. Histology revealed adipocytes with small unilocular fat droplets and a large eosinophilic cytoplasm intermingled with connective tissue in the innermost layers of blubber. Chemistry revealed a brown adipocyte-specific mitochondrial protein, uncoupling protein 1 (UCP1), within these same adipocytes, but not those distributed elsewhere throughout the blubber. Western blot analysis of extracts from the inner blubber layer confirmed that the immunohistochemical positive reaction was specific to UCP1 and that this adipose tissue was BAT. To better understand the distribution of BAT throughout the entire cetacean body, cadavers were subjected to computed tomography (CT) scanning. Resulting imagery, coupled with histological corroboration of fine tissue structure, revealed adipocytes intermingled with connective tissue in the lowest layer of blubber were distributed within a thin, highly dense layer that extended the length of the body, with the exception of the rostrum, fin and fluke regions. As such, we describe BAT effectively enveloping the cetacean body. Our results suggest that delphinoid blubber could serve a role additional to those frequently attributed to it: simple insulation blanket, energy storage, hydrodynamic streamlining or contributor to positive buoyancy. We believe delphinoid BAT might also function like an electric blanket, enabling animals to frequent waters cooler than blubber as an insulator alone might otherwise allow an animal to withstand, or allow animals to maintain body temperature in cool waters during

  14. Brown adipose tissue in cetacean blubber.

    PubMed

    Hashimoto, Osamu; Ohtsuki, Hirofumi; Kakizaki, Takehiko; Amou, Kento; Sato, Ryo; Doi, Satoru; Kobayashi, Sara; Matsuda, Ayaka; Sugiyama, Makoto; Funaba, Masayuki; Matsuishi, Takashi; Terasawa, Fumio; Shindo, Junji; Endo, Hideki

    2015-01-01

    Brown adipose tissue (BAT) plays an important role in thermoregulation in species living in cold environments, given heat can be generated from its chemical energy reserves. Here we investigate the existence of BAT in blubber in four species of delphinoid cetacean, the Pacific white-sided and bottlenose dolphins, Lagenorhynchus obliquidens and Tursiops truncates, and Dall's and harbour porpoises, Phocoenoides dalli and Phocoena phocoena. Histology revealed adipocytes with small unilocular fat droplets and a large eosinophilic cytoplasm intermingled with connective tissue in the innermost layers of blubber. Chemistry revealed a brown adipocyte-specific mitochondrial protein, uncoupling protein 1 (UCP1), within these same adipocytes, but not those distributed elsewhere throughout the blubber. Western blot analysis of extracts from the inner blubber layer confirmed that the immunohistochemical positive reaction was specific to UCP1 and that this adipose tissue was BAT. To better understand the distribution of BAT throughout the entire cetacean body, cadavers were subjected to computed tomography (CT) scanning. Resulting imagery, coupled with histological corroboration of fine tissue structure, revealed adipocytes intermingled with connective tissue in the lowest layer of blubber were distributed within a thin, highly dense layer that extended the length of the body, with the exception of the rostrum, fin and fluke regions. As such, we describe BAT effectively enveloping the cetacean body. Our results suggest that delphinoid blubber could serve a role additional to those frequently attributed to it: simple insulation blanket, energy storage, hydrodynamic streamlining or contributor to positive buoyancy. We believe delphinoid BAT might also function like an electric blanket, enabling animals to frequent waters cooler than blubber as an insulator alone might otherwise allow an animal to withstand, or allow animals to maintain body temperature in cool waters during

  15. Regulation of lipin1 by nutritional status, adiponectin, sex and pituitary function in rat white adipose tissue.

    PubMed

    González, C Ruth; Novelle, Marta G; Caminos, Jorge E; Vázquez, María J; Luque, Raul M; López, Miguel; Nogueiras, Ruben; Diéguez, Carlos

    2012-02-01

    Lipin1 is a member of the lipin protein family that plays an important role in the regulation of lipid metabolism. The endogenous role of lipin1 was demonstrated by the fact that mutations in lipin1 caused lipodystrophy and metabolic disorders. The aim of this study was to assess the influence of nutritional status, pregnancy, insulin-sensitizers and pituitary hormones on lipin1 mRNA levels in adipose tissue of rats. Lipin1 gene expression was induced in conditions of hypoleptinemia (fasting) and leptin resistance (high fat diet), whereas it was decreased by high circulating leptin levels (leptin administration, pregnancy) and in leptin-deficient mice. Lipin1 mRNA levels were also decreased in adiponectin-deficient mice. Lipin1 mRNA levels are influenced by age in female rats, with peak expression at 25th day of life and decreasing thereafter. Consistently, ovariectomy increased lipin1 expression indicating that estrogens modulate lipin1. Finally, lipin1 was also regulated by pituitary hormones, since its expression was modified by thyroid status and growth hormone deficiency. Our observations indicate that: a) gWAT lipin1 mRNA levels are regulated by nutritional status, and leptin plays an important role in this regard, b) lipin1 is modulated by adiponectin, c) lipin1 is influenced by age and sex, and d) alterations in pituitary function modify lipin1 mRNA levels. To dissect the complicated interactions between key regulators of lipid metabolism like lipin1, may be important for the development of new therapies for the treatment and prevention of obesity and its associated disorders.

  16. Brain-adipose tissue neural crosstalk.

    PubMed

    Bartness, Timothy J; Song, C Kay

    2007-07-24

    The preponderance of basic obesity research focuses on its development as affected by diet and other environmental factors, genetics and their interactions. By contrast, we have been studying the reversal of a naturally-occurring seasonal obesity in Siberian hamsters. In the course of this work, we determined that the sympathetic innervation of white adipose tissue (WAT) is the principal initiator of lipid mobilization not only in these animals, but in all mammals including humans. We present irrefutable evidence for the sympathetic nervous system (SNS) innervation of WAT with respect to neuroanatomy (including its central origins as revealed by transneuronal viral tract tracers), neurochemistry (norepinephrine turnover studies) and function (surgical and chemical denervation). A relatively unappreciated role of WAT SNS innervation also is reviewed--the control of fat cell proliferation as shown by selective chemical denervation that triggers adipocyte proliferation, although the precise mechanism by which this occurs presently is unknown. There is no, however, equally strong evidence for the parasympathetic innervation of this tissue; indeed, the data largely are negative severely questioning its existence and importance. Convincing evidence also is given for the sensory innervation of WAT (as shown by tract tracing and by markers for sensory nerves in WAT), with suggestive data supporting a possible role in conveying information on the degree of adiposity to the brain. Collectively, these data offer an additional or alternative view to the predominate one of the control of body fat stores via circulating factors that serve as efferent and afferent communicators.

  17. cGMP and Brown Adipose Tissue.

    PubMed

    Hoffmann, Linda S; Larson, Christopher J; Pfeifer, Alexander

    2016-01-01

    The second messenger cyclic guanosine monophosphate (cGMP) is a key mediator in physiological processes such as vascular tone, and its essential involvement in pathways regulating metabolism has been recognized in recent years. Here, we focus on the fundamental role of cGMP in brown adipose tissue (BAT) differentiation and function. In contrast to white adipose tissue (WAT), which stores energy in the form of lipids, BAT consumes energy stored in lipids to generate heat. This so-called non-shivering thermogenesis takes place in BAT mitochondria, which express the specific uncoupling protein 1 (UCP1). The energy combusting properties of BAT render it a promising target in antiobesity strategies in which BAT could burn the surplus energy that has accumulated in obese and overweight individuals. cGMP is generated by guanylyl cyclases upon activation by nitric oxide or natriuretic peptides. It affects several downstream molecules including cGMP-receptor proteins such as cGMP-dependent protein kinase and is degraded by phosphodiesterases. The cGMP pathway contains several signaling molecules that can increase cGMP signaling, resulting in activation and recruitment of brown adipocytes, and hence can enhance the energy combusting features of BAT. In this review we highlight recent results showing the physiological significance of cGMP signaling in BAT, as well as pharmacological options targeting cGMP signaling that bear a high potential to become BAT-centered therapies for the treatment of obesity.

  18. An endocrine role for brown adipose tissue?

    PubMed

    Villarroya, Joan; Cereijo, Rubén; Villarroya, Francesc

    2013-09-01

    White adipose tissue is recognized as both a site of energy storage and an endocrine organ that produces a myriad of endocrine factors called adipokines. Brown adipose tissue (BAT) is the main site of nonshivering thermogenesis in mammals. The amount and activity of brown adipocytes are associated with protection against obesity and associated metabolic alterations. These effects of BAT are traditionally attributed to its capacity for the oxidation of fatty acids and glucose to sustain thermogenesis. However, recent data suggest that the beneficial effects of BAT could involve a previously unrecognized endocrine role through the release of endocrine factors. Several signaling molecules with endocrine properties have been found to be released by brown fat, especially under conditions of thermogenic activation. Moreover, experimental BAT transplantation has been shown to improve glucose tolerance and insulin sensitivity mainly by influencing hepatic and cardiac function. It has been proposed that these effects are due to the release of endocrine factors by brown fat, such as insulin-like growth factor I, interleukin-6, or fibroblast growth factor-21. Further research is needed to determine whether brown fat plays an endocrine role and, if so, to comprehensively identify which endocrine factors are released by BAT. Such research may reveal novel clues for the observed association between brown adipocyte activity and a healthy metabolic profile, and it could also enlarge a current view of potential therapeutic tools for obesity and associated metabolic diseases.

  19. Brown adipose tissue growth and development.

    PubMed

    Symonds, Michael E

    2013-01-01

    Brown adipose tissue is uniquely able to rapidly produce large amounts of heat through activation of uncoupling protein (UCP) 1. Maximally stimulated brown fat can produce 300 watts/kg of heat compared to 1 watt/kg in all other tissues. UCP1 is only present in small amounts in the fetus and in precocious mammals, such as sheep and humans; it is rapidly activated around the time of birth following the substantial rise in endocrine stimulatory factors. Brown adipose tissue is then lost and/or replaced with white adipose tissue with age but may still contain small depots of beige adipocytes that have the potential to be reactivated. In humans brown adipose tissue is retained into adulthood, retains the capacity to have a significant role in energy balance, and is currently a primary target organ in obesity prevention strategies. Thermogenesis in brown fat humans is environmentally regulated and can be stimulated by cold exposure and diet, responses that may be further modulated by photoperiod. Increased understanding of the primary factors that regulate both the appearance and the disappearance of UCP1 in early life may therefore enable sustainable strategies in order to prevent excess white adipose tissue deposition through the life cycle.

  20. Brown Adipose Tissue Growth and Development

    PubMed Central

    Symonds, Michael E.

    2013-01-01

    Brown adipose tissue is uniquely able to rapidly produce large amounts of heat through activation of uncoupling protein (UCP) 1. Maximally stimulated brown fat can produce 300 watts/kg of heat compared to 1 watt/kg in all other tissues. UCP1 is only present in small amounts in the fetus and in precocious mammals, such as sheep and humans; it is rapidly activated around the time of birth following the substantial rise in endocrine stimulatory factors. Brown adipose tissue is then lost and/or replaced with white adipose tissue with age but may still contain small depots of beige adipocytes that have the potential to be reactivated. In humans brown adipose tissue is retained into adulthood, retains the capacity to have a significant role in energy balance, and is currently a primary target organ in obesity prevention strategies. Thermogenesis in brown fat humans is environmentally regulated and can be stimulated by cold exposure and diet, responses that may be further modulated by photoperiod. Increased understanding of the primary factors that regulate both the appearance and the disappearance of UCP1 in early life may therefore enable sustainable strategies in order to prevent excess white adipose tissue deposition through the life cycle. PMID:24278771

  1. UCP1 in adipose tissues: two steps to full browning.

    PubMed

    Kalinovich, Anastasia V; de Jong, Jasper M A; Cannon, Barbara; Nedergaard, Jan

    2017-03-01

    The possibility that brown adipose tissue thermogenesis can be recruited in order to combat the development of obesity has led to a high interest in the identification of "browning agents", i.e. agents that increase the amount and activity of UCP1 in brown and brite/beige adipose tissues. However, functional analysis of the browning process yields confusingly different results when the analysis is performed in one of two alternative steps. Thus, in one of the steps, using cold acclimation as a potent model browning agent, we find that if the browning process is followed in mice initially housed at 21 °C (the most common procedure), there is only weak molecular evidence for increases in UCP1 gene expression or UCP1 protein abundance in classical brown adipose tissue; however, in brite/beige adipose depots, there are large increases, apparently associating functional browning with events only in the brite/beige tissues. Contrastingly, in another step, if the process is followed starting with mice initially housed at 30 °C (thermoneutrality for mice, thus similar to normal human conditions), large increases in UCP1 gene expression and UCP1 protein abundance are observed in the classical brown adipose tissue depots; there is then practically no observable UCP1 gene expression in brite/beige tissues. This apparent conundrum can be resolved when it is realized that the classical brown adipose tissue at 21 °C is already essentially fully differentiated and thus expands extensively through proliferation upon further browning induction, rather than by further enhancing cellular differentiation. When the limiting factor for thermogenesis, i.e. the total amount of UCP1 protein per depot, is analyzed, classical brown adipose tissue is by far the predominant site for the browning process, irrespective of which of the two steps is analyzed. There are to date no published data demonstrating that alternative browning agents would selectively promote brite/beige tissues

  2. Adipose Tissue Dysfunction: Clinical Relevance and Diagnostic Possibilities.

    PubMed

    Schrover, I M; Spiering, W; Leiner, T; Visseren, F L J

    2016-04-01

    Adipose tissue dysfunction is defined as an imbalance between pro- and anti-inflammatory adipokines, causing insulin resistance, systemic low-grade inflammation, hypercoagulability, and elevated blood pressure. These can lead to cardiovascular disease and diabetes mellitus type 2. Although quantity of adipose tissue is an important determinant of adipose tissue dysfunction, it can be diagnosed in both obese and lean individuals. This implies that not only quantity of adipose tissue should be used as a measure for adipose tissue dysfunction. Instead, focus should be on measuring quality of adipose tissue, which can be done with diagnostic modalities ranging from anthropometric measurements to tissue biopsies and advanced imaging techniques. In daily clinical practice, high quantity of visceral adipose tissue (reflected in high waist circumference or adipose tissue imaging), insulin resistance, or presence of the metabolic syndrome are easy and low-cost diagnostic modalities to evaluate presence or absence of adipose tissue dysfunction.

  3. SIRT1-Mediated eNAMPT Secretion from Adipose Tissue Regulates Hypothalamic NAD+ and Function in Mice.

    PubMed

    Yoon, Myeong Jin; Yoshida, Mitsukuni; Johnson, Sean; Takikawa, Akiko; Usui, Isao; Tobe, Kazuyuki; Nakagawa, Takashi; Yoshino, Jun; Imai, Shin-ichiro

    2015-05-05

    Nicotinamide phosphoribosyltransferase (NAMPT), the key NAD(+) biosynthetic enzyme, has two different forms, intra- and extracellular (iNAMPT and eNAMPT), in mammals. However, the significance of eNAMPT secretion remains unclear. Here we demonstrate that deacetylation of iNAMPT by the mammalian NAD(+)-dependent deacetylase SIRT1 predisposes the protein to secretion in adipocytes. NAMPT mutants reveal that SIRT1 deacetylates lysine 53 (K53) and enhances eNAMPT activity and secretion. Adipose tissue-specific Nampt knockout and knockin (ANKO and ANKI) mice show reciprocal changes in circulating eNAMPT, affecting hypothalamic NAD(+)/SIRT1 signaling and physical activity accordingly. The defect in physical activity observed in ANKO mice is ameliorated by nicotinamide mononucleotide (NMN). Furthermore, administration of a NAMPT-neutralizing antibody decreases hypothalamic NAD(+) production, and treating ex vivo hypothalamic explants with purified eNAMPT enhances NAD(+), SIRT1 activity, and neural activation. Thus, our findings indicate a critical role of adipose tissue as a modulator for the regulation of NAD(+) biosynthesis at a systemic level.

  4. Insulin effects in muscle and adipose tissue.

    PubMed

    Dimitriadis, George; Mitrou, Panayota; Lambadiari, Vaia; Maratou, Eirini; Raptis, Sotirios A

    2011-08-01

    The major effects of insulin on muscle and adipose tissue are: (1) Carbohydrate metabolism: (a) it increases the rate of glucose transport across the cell membrane, (b) it increases the rate of glycolysis by increasing hexokinase and 6-phosphofructokinase activity, (c) it stimulates the rate of glycogen synthesis and decreases the rate of glycogen breakdown. (2) Lipid metabolism: (a) it decreases the rate of lipolysis in adipose tissue and hence lowers the plasma fatty acid level, (b) it stimulates fatty acid and triacylglycerol synthesis in tissues, (c) it increases the uptake of triglycerides from the blood into adipose tissue and muscle, (d) it decreases the rate of fatty acid oxidation in muscle and liver. (3) Protein metabolism: (a) it increases the rate of transport of some amino acids into tissues, (b) it increases the rate of protein synthesis in muscle, adipose tissue, liver, and other tissues, (c) it decreases the rate of protein degradation in muscle (and perhaps other tissues). These insulin effects serve to encourage the synthesis of carbohydrate, fat and protein, therefore, insulin can be considered to be an anabolic hormone. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  5. Proteomic Profiling of Adipose Tissue from Zmpste24−/− Mice, a Model of Lipodystrophy and Premature Aging, Reveals Major Changes in Mitochondrial Function and Vimentin Processing*

    PubMed Central

    Peinado, Juan R.; Quirós, Pedro M.; Pulido, Marina R.; Mariño, Guillermo; Martínez-Chantar, Maria L.; Vázquez-Martínez, Rafael; Freije, José M. P.; López-Otín, Carlos; Malagón, María M.

    2011-01-01

    Lipodystrophy is a major disease involving severe alterations of adipose tissue distribution and metabolism. Mutations in genes encoding the nuclear envelope protein lamin A or its processing enzyme, the metalloproteinase Zmpste24, cause diverse human progeroid syndromes that are commonly characterized by a selective loss of adipose tissue. Similarly to humans, mice deficient in Zmpste24 accumulate prelamin A and display phenotypic features of accelerated aging, including lipodystrophy. Herein, we report the proteome and phosphoproteome of adipose tissue as well as serum metabolome in lipodystrophy by using Zmpste24−/− mice as experimental model. We show that Zmpste24 deficiency enhanced lipolysis, fatty acid biogenesis and β-oxidation as well as decreased fatty acid re-esterification, thus pointing to an increased partitioning of fatty acid toward β-oxidation and away from storage that likely underlies the observed size reduction of Zmpste24-null adipocytes. Besides the mitochondrial proteins related to lipid metabolism, other protein networks related to mitochondrial function, including those involved in tricarboxylic acid cycle and oxidative phosphorylation, were up-regulated in Zmpste24−/− mice. These results, together with the observation of an increased mitochondrial response to oxidative stress, support the relationship between defective prelamin A processing and mitochondrial dysfunction and highlight the relevance of oxidative damage in lipoatrophy and aging. We also show that absence of Zmpste24 profoundly alters the processing of the cytoskeletal protein vimentin and identify a novel protein dysregulated in lipodystrophy, High-Mobility Group Box-1 Protein. Finally, we found several lipid derivates with important roles in energy balance, such as Lysophosphatidylcholine or 2-arachidonoylglycerol, to be dysregulated in Zmpste24−/− serum. Together, our findings in Zmpste24−/− mice may be useful to unveil the mechanisms underlying adipose

  6. [Interests and potentials of adipose tissue in scleroderma].

    PubMed

    Daumas, A; Eraud, J; Hautier, A; Sabatier, F; Magalon, G; Granel, B

    2013-12-01

    Systemic sclerosis is a disorder involving the connective tissue, arterioles and microvessels. It is characterized by skin and visceral fibrosis and ischemic phenomena. Currently, therapy is limited and no antifibrotic treatment has proven its efficacy. Beyond some severe organ lesions (pulmonary arterial hypertension, pulmonary fibrosis, scleroderma renal crisis), which only concern a minority of patients, the skin sclerosis of hands and face and the vasculopathy lead to physical and psychological disability in most patients. Thus, functional improvement of hand motion and face represents a priority for patient therapy. Due to its easy obtention by fat lipopaspirate and adipocytes survival, re injection of adipose tissue is a common therapy used in plastic surgery for its voluming effect. Identification and characterization of the adipose tissue-derived stroma vascular fraction, mainly including mesenchymal stem cells, have revolutionized the science showing that adipose tissue is a valuable source of multipotent stem cells, able to migrate to site of injury and to differentiate according to the receiver tissue's needs. Due to easy harvest by liposuction, its abundance in mesenchymal cells far higher that the bone marrow, and stroma vascular fraction's ability to differentiate and secrete growth angiogenic and antiapoptotic factors, the use of adipose tissue is becoming more attractive in regenerative medicine. We here present the interest of adipose tissue use in the treatment of the hands and face in scleroderma.

  7. Histochemical and functional improvement of adipose-derived stem cell-based tissue-engineered cartilage by hyperbaric oxygen/air treatment in a rabbit articular defect model.

    PubMed

    Dai, Niann-Tzyy; Fan, Gang-Yi; Liou, Nien-Hsien; Wang, Yi-Wen; Fu, Keng-Yen; Ma, Kuo-Hsing; Liu, Jiang-Chuan; Chang, Shun-Cheng; Huang, Kun-Lun; Dai, Lien-Guo; Chen, Shyi-Gen; Chen, Tim-Mo

    2015-05-01

    Cartilage is exposed to compression forces during joint loading. Therefore, exogenous stimuli are frequently used in cartilage tissue engineering strategies to enhance chondrocyte differentiation and extracellular matrix (ECM) secretion. In this study, human adipose-derived stem cells were seeded on a gelatin/polycaprolactone scaffold to evaluate the histochemical and functional improvement of tissue-engineered cartilage after hyperbaric oxygen/air treatment in a rabbit articular defect model. Behavior tests showed beneficial effects on weight-bearing and rear leg-supporting capacities after treatment of tissue-engineered cartilage with 2.5 ATA oxygen or air. Moreover, positron emission tomography images and immunohistochemistry staining demonstrated hydroxyapatite formation and increased ECM synthesis, respectively, at the tissue-engineered cartilage graft site after high pressure oxygen/air treatment. Based on these results, we concluded that hyperbaric oxygen and air treatment can improve the quality of tissue-engineered cartilage in vivo by increasing the synthesis of ECM.

  8. The Relationship between the Severity of Coronary Artery Disease and Epicardial Adipose Tissue Depends on The Left Ventricular Function

    PubMed Central

    Doesch, Christina; Süselbeck, Tim; Haghi, Dariusch; Streitner, Florian; Schoenberg, Stefan O.; Borggrefe, Martin; Papavassiliu, Theano

    2012-01-01

    Background Epicardial adipose tissue (EAT) is an active metabolic and endocrine organ. Previous studies focusing mainly on patients with preserved left ventricular function (LVF) could show a correlation between increased amounts of EAT and the extent and activity of coronary artery disease (CAD). However, to date, there are no data available about the relationship between EAT and the severity of CAD with respect to the whole spectrum of LVF impairment. Therefore, we evaluated this relationship in patients with CAD. Methods 250 patients with CAD and 50 healthy controls underwent CMR examination to assess EAT. The severity of CAD was defined using the angiographic Gensini score (GSS). Results The GSS ranged from 2–364. Linear regression analysis revealed a significant correlation between EAT and GSS (r = 0.177, p = 0.01). Patients with mild (GSS≤10) and moderate CAD (GSS>10−≤40) showed comparable EAT to healthy controls. However, in patients with severe CAD (GSS>40) EAT was significantly reduced (p<0.0001) compared to healthy controls. Interestingly, patients with the same GSS revealed different EAT depending on the left ventricular function (LVF). Patients with preserved LVF (LVF≥50%) showed more EAT mass compared to those with reduced LVF (LVF<50%) regardless of the GSS. In patients with preserved LVF and mild CAD, EAT was comparable to healthy controls (61.8±19.4 g vs. 62.9±14.4 g, p = 0.8). In patients with moderate CAD, EAT rose significantly to 83.1±24.9 g (p = 0.01) and started to decline to 66.4±23.6 g in patients with severe CAD (p = 0.03). Contrary, in CAD patients with reduced LVF, EAT was already significantly reduced in patients with mild CAD as compared to healthy controls (p = 0.001) and showed a stepwise decline with increasing CAD severity. Conclusion The relationship between EAT and the severity of CAD depends on LVF. These findings emphasize the multifactorial interaction between EAT and the severity of CAD

  9. Regulation of cholesteryl ester transfer activity in adipose tissue: comparison between hamster and rat species.

    PubMed

    Shen, G X; Angel, A

    1995-07-01

    The present study demonstrates cholesteryl ester transfer activity (CETA) in cultured hamster and rat adipose tissue. Cultured hamster and rat adipose tissue fragments released CETA into the conditioned medium, and this was associated with a reciprocal decrease in adipose tissue CETA. Regional variations in adipose CETA were observed. The levels of CETA released from cultured hamster and rat adipocytes were higher than those from adipose tissue fragments. In hamsters but not in rats, the secretion of CETA from cultured adipose tissue was increased by insulin and inhibited by EDTA in a dose-dependent fashion. Monoclonal antibodies against human cholesteryl ester transfer protein inhibited the CETA secreted from hamster adipose tissue but not that from rat adipose tissue. Fasting for 24 h and a high-cholesterol saturated fat-rich diet increased adipose CETA in hamsters and rats, and this was associated with an elevation of plasma CETA only in hamsters. This supports the view that, in hamsters, adipose CETA has in situ and intravascular functions, whereas in rats the role of adipose CETA is restricted to tissue-specific functions. Hamster cholesteryl ester transfer protein may differ from rat adipose-associated CETA in the structure of the active site and the regulatory mechanism for its secretion.

  10. How to Measure Adipose Tissue Insulin Sensitivity.

    PubMed

    Søndergaard, Esben; Espinosa De Ycaza, Ana Elena; Morgan-Bathke, Maria; Jensen, Michael D

    2017-04-01

    Adipose tissue insulin resistance may cause hepatic and skeletal muscle insulin resistance by releasing excess free fatty acids (FFAs). Because no consensus exists on how to quantify adipose tissue insulin sensitivity we compared three methods for measuring adipose tissue insulin sensitivity: the single step insulin clamp, the multistep pancreatic clamp, and the adipose tissue insulin resistance index (Adipo-IR). We studied insulin sensitivity in 25 adults by measuring the insulin concentration resulting in 50% suppression of palmitate flux (IC50) using both a multistep pancreatic clamp and a one-step hyperinsulinemic-euglycemic clamp. Palmitate kinetics were measured using a continuous infusion of [U-13C]palmitate. Adipo-IR was calculated from fasting insulin and fasting FFA concentrations. Adipo-IR was reproducible (sample coefficient of variability, 10.0%) and correlated with the IC50 measured by the multistep pancreatic clamp technique (r, 0.86; P < 0.001). Age and physical fitness were significant predictors of the residual variation between Adipo-IR and IC50, with a positive relationship with age (r, 0.47; P = 0.02) and a negative association with VO2 peak (r, -0.46; P = 0.02). Likewise, IC50 measured by the multistep pancreatic clamp technique correlated with IC50 measured using the one-step hyperinsulinemic-euglycemic clamp technique (r, 0.73; P < 0.001). Adipo-IR and the one-step hyperinsulinemic-euglycemic clamp technique using a palmitate tracer are good predictors of a gold standard measure of adipose tissue insulin sensitivity. However, age and physical fitness systematically affect the predictive values. Although Adipo-IR is suitable for larger population studies, the multistep pancreatic clamp technique is probably needed for mechanistic studies of adipose tissue insulin action.

  11. Functional abolition of carotid body activity restores insulin action and glucose homeostasis in rats: key roles for visceral adipose tissue and the liver.

    PubMed

    Sacramento, Joana F; Ribeiro, Maria J; Rodrigues, Tiago; Olea, Elena; Melo, Bernardete F; Guarino, Maria P; Fonseca-Pinto, Rui; Ferreira, Cristiana R; Coelho, Joana; Obeso, Ana; Seiça, Raquel; Matafome, Paulo; Conde, Sílvia V

    2017-01-01

    We recently described that carotid body (CB) over-activation is involved in the aetiology of insulin resistance and arterial hypertension in animal models of the metabolic syndrome. Additionally, we have demonstrated that CB activity is increased in animal models of insulin resistance, and that carotid sinus nerve (CSN) resection prevents the development of insulin resistance and arterial hypertension induced by high-energy diets. Here, we tested whether the functional abolition of CB by CSN transection would reverse pre-established insulin resistance, dyslipidaemia, obesity, autonomic dysfunction and hypertension in animal models of the metabolic syndrome. The effect of CSN resection on insulin signalling pathways and tissue-specific glucose uptake was evaluated in skeletal muscle, adipose tissue and liver. Experiments were performed in male Wistar rats submitted to two high-energy diets: a high-fat diet, representing a model of insulin resistance, hypertension and obesity, and a high-sucrose diet, representing a lean model of insulin resistance and hypertension. Half of each group was submitted to chronic bilateral resection of the CSN. Age-matched control rats were also used. CSN resection normalised systemic sympathetic nervous system activity and reversed weight gain induced by high-energy diets. It also normalised plasma glucose and insulin levels, insulin sensitivity lipid profile, arterial pressure and endothelial function by improving glucose uptake by the liver and perienteric adipose tissue. We concluded that functional abolition of CB activity restores insulin sensitivity and glucose homeostasis by positively affecting insulin signalling pathways in visceral adipose tissue and liver.

  12. A stringent validation of mouse adipose tissue identity markers.

    PubMed

    de Jong, Jasper M A; Larsson, Ola; Cannon, Barbara; Nedergaard, Jan

    2015-06-15

    The nature of brown adipose tissue in humans is presently debated: whether it is classical brown or of brite/beige nature. The dissimilar developmental origins and proposed distinct functions of the brown and brite/beige tissues make it essential to ascertain the identity of human depots with the perspective of recruiting and activating them for the treatment of obesity and type 2 diabetes. For identification of the tissues, a number of marker genes have been proposed, but the validity of the markers has not been well documented. We used established brown (interscapular), brite (inguinal), and white (epididymal) mouse adipose tissues and corresponding primary cell cultures as validators and examined the informative value of a series of suggested markers earlier used in the discussion considering the nature of human brown adipose tissue. Most of these markers unexpectedly turned out to be noninformative concerning tissue classification (Car4, Cited1, Ebf3, Eva1, Fbxo31, Fgf21, Lhx8, Hoxc8, and Hoxc9). Only Zic1 (brown), Cd137, Epsti1, Tbx1, Tmem26 (brite), and Tcf21 (white) proved to be informative in these three tissues. However, the expression of the brite markers was not maintained in cell culture. In a more extensive set of adipose depots, these validated markers provide new information about depot identity. Principal component analysis supported our single-gene conclusions. Furthermore, Zic1, Hoxc8, Hoxc9, and Tcf21 displayed anteroposterior expression patterns, indicating a relationship between anatomic localization and adipose tissue identity (and possibly function). Together, the observed expression patterns of these validated marker genes necessitates reconsideration of adipose depot identity in mice and humans.

  13. Carotenoids in Adipose Tissue Biology and Obesity.

    PubMed

    Bonet, M Luisa; Canas, Jose A; Ribot, Joan; Palou, Andreu

    2016-01-01

    Cell, animal and human studies dealing with carotenoids and carotenoid derivatives as nutritional regulators of adipose tissue biology with implications for the etiology and management of obesity and obesity-related metabolic diseases are reviewed. Most studied carotenoids in this context are β-carotene, cryptoxanthin, astaxanthin and fucoxanthin, together with β-carotene-derived retinoids and some other apocarotenoids. Studies indicate an impact of these compounds on essential aspects of adipose tissue biology including the control of adipocyte differentiation (adipogenesis), adipocyte metabolism, oxidative stress and the production of adipose tissue-derived regulatory signals and inflammatory mediators. Specific carotenoids and carotenoid derivatives restrain adipogenesis and adipocyte hypertrophy while enhancing fat oxidation and energy dissipation in brown and white adipocytes, and counteract obesity in animal models. Intake, blood levels and adipocyte content of carotenoids are reduced in human obesity. Specifically designed human intervention studies in the field, though still sparse, indicate a beneficial effect of carotenoid supplementation in the accrual of abdominal adiposity. In summary, studies support a role of specific carotenoids and carotenoid derivatives in the prevention of excess adiposity, and suggest that carotenoid requirements may be dependent on body composition.

  14. Effect of dietary lipid structure in early postnatal life on mouse adipose tissue development and function in adulthood.

    PubMed

    Oosting, Annemarie; van Vlies, Naomi; Kegler, Diane; Schipper, Lidewij; Abrahamse-Berkeveld, Marieke; Ringler, Silvia; Verkade, Henkjan J; van der Beek, Eline M

    2014-01-28

    Obese individuals have more (hyperplastic) and larger (hypertrophic) adipocytes in their white adipose tissue (WAT) than normal-weight individuals. The difference in cell number emerges early in childhood, suggesting that this is a critical period for being susceptible to obesity. Breast-feeding has been shown to be protective against obesity, and we have previously shown in mice that the physical structure of lipids in human milk may contribute to this protective effect. In the present study, we investigated how differences in the physical structure of lipids in the early diet may modulate adipose tissue development. Male mice were fed a diet containing control infant milk formula (Control IMF; Danone Research) or Nuturis® (Concept IMF with large phospholipid-coated lipid droplets; Danone Research) from postnatal day (PN)16 to 42. Subsequently, mice were challenged with a moderate Western-style diet (WSD) until PN98, and body composition was monitored by dual-energy X-ray absorptiometry. Epididymal WAT was analysed for adipocyte size, number and gene expression of metabolic transcription factors. Early Concept IMF exposure reduced fat accumulation during the WSD challenge by 30 % compared with the Control IMF. It reduced adipocyte size without affecting adipocyte number in adult mice. The Concept IMF decreased the expression of PPARγ, CCAAT/enhancer-binding protein and retinoid X receptor α in WAT in adulthood, key regulators of metabolic activity. In conclusion, Concept IMF exposure in early life reduced susceptibility to obesity in adult life, by preventing adipocyte hypertrophia upon adult dietary challenge without affecting adipogenesis. These data emphasise the importance of the physical properties of dietary lipids in early life in obesity risk later in life.

  15. Adipose tissue, obesity and adipokines: role in cancer promotion.

    PubMed

    Booth, Andrea; Magnuson, Aaron; Fouts, Josephine; Foster, Michelle

    2015-01-01

    Adipose tissue is a complex organ with endocrine, metabolic and immune regulatory roles. Adipose depots have been characterized to release several adipocytokines that work locally in an autocrine and paracrine fashion or peripherally in an endocrine fashion. Adipocyte hypertrophy and excessive adipose tissue accumulation, as occurs during obesity, dysregulates the microenvironment within adipose depots and systemically alters peripheral tissue metabolism. The term "adiposopathy" is used to describe this promotion of pathogenic adipocytes and associated adipose - elated disorders. Numerous epidemiological studies confirm an association between obesity and various cancer forms. Proposed mechanisms that link obesity/adiposity to high cancer risk and mortality include, but are not limited to, obesity-related insulin resistance, hyperinsulinemia, sustained hyperglycemia, glucose intolerance, oxidative stress, inflammation and/or adipocktokine production. Several epidemiological studies have demonstrated a relationship between specific circulating adipocytokines and cancer risk. The aim of this review is to define the function, in normal weight and obesity states, of well-characterized and novel adipokines including leptin, adiponectin, apelin, visfatin, resistin, chemerin, omentin, nesfatin and vaspin and summarize the data that relates their dysfunction, whether associated or direct effects, to specific cancer outcomes. Overall research suggests most adipokines promote cancer cell progression via enhancement of cell proliferation and migration, inflammation and anti-apoptosis pathways, which subsequently can prompt cancer metastasis. Further research and longitudinal studies are needed to define the specific independent and additive roles of adipokines in cancer progression and reoccurrence.

  16. Natural killer T cells in adipose tissue prevent insulin resistance.

    PubMed

    Schipper, Henk S; Rakhshandehroo, Maryam; van de Graaf, Stan F J; Venken, Koen; Koppen, Arjen; Stienstra, Rinke; Prop, Serge; Meerding, Jenny; Hamers, Nicole; Besra, Gurdyal; Boon, Louis; Nieuwenhuis, Edward E S; Elewaut, Dirk; Prakken, Berent; Kersten, Sander; Boes, Marianne; Kalkhoven, Eric

    2012-09-01

    Lipid overload and adipocyte dysfunction are key to the development of insulin resistance and can be induced by a high-fat diet. CD1d-restricted invariant natural killer T (iNKT) cells have been proposed as mediators between lipid overload and insulin resistance, but recent studies found decreased iNKT cell numbers and marginal effects of iNKT cell depletion on insulin resistance under high-fat diet conditions. Here, we focused on the role of iNKT cells under normal conditions. We showed that iNKT cell-deficient mice on a low-fat diet, considered a normal diet for mice, displayed a distinctive insulin resistance phenotype without overt adipose tissue inflammation. Insulin resistance was characterized by adipocyte dysfunction, including adipocyte hypertrophy, increased leptin, and decreased adiponectin levels. The lack of liver abnormalities in CD1d-null mice together with the enrichment of CD1d-restricted iNKT cells in both mouse and human adipose tissue indicated a specific role for adipose tissue-resident iNKT cells in the development of insulin resistance. Strikingly, iNKT cell function was directly modulated by adipocytes, which acted as lipid antigen-presenting cells in a CD1d-mediated fashion. Based on these findings, we propose that, especially under low-fat diet conditions, adipose tissue-resident iNKT cells maintain healthy adipose tissue through direct interplay with adipocytes and prevent insulin resistance.

  17. Adipocyte insulin receptor activity maintains adipose tissue mass and lifespan.

    PubMed

    Friesen, Max; Hudak, Carolyn S; Warren, Curtis R; Xia, Fang; Cowan, Chad A

    2016-08-05

    Type 2 diabetes follows a well-defined progressive pathogenesis, beginning with insulin resistance in metabolic tissues such as the adipose. Intracellular signaling downstream of insulin receptor activation regulates critical metabolic functions of adipose tissue, including glucose uptake, lipogenesis, lipolysis and adipokine secretion. Previous studies have used the aP2 promoter to drive Cre recombinase expression in adipose tissue. Insulin receptor (IR) knockout mice created using this aP2-Cre strategy (FIRKO mice) were protected from obesity and glucose intolerance. Later studies demonstrated the promiscuity of the aP2 promoter, casting doubts upon the tissue specificity of aP2-Cre models. It is our goal to use the increased precision of the Adipoq promoter to investigate adipocyte-specific IR function. Towards this end we generated an adipocyte-specific IR knockout (AIRKO) mouse using an Adipoq-driven Cre recombinase. Here we report AIRKO mice are less insulin sensitive throughout life, and less glucose tolerant than wild-type (WT) littermates at the age of 16 weeks. In contrast to WT littermates, the insulin sensitivity of AIRKO mice is unaffected by age or dietary regimen. At any age, AIRKO mice are comparably insulin resistant to old or obese WT mice and have a significantly reduced lifespan. Similar results were obtained when these phenotypes were re-examined in FIRKO mice. We also found that the AIRKO mouse is protected from high-fat diet-induced weight gain, corresponding with a 90% reduction in tissue weight of major adipose depots compared to WT littermates. Adipose tissue mass reduction is accompanied by hepatomegaly and increased hepatic steatosis. These data indicate that adipocyte IR function is crucial to systemic energy metabolism and has profound effects on adiposity, hepatic homeostasis and lifespan. Copyright © 2016. Published by Elsevier Inc.

  18. Brown adipose tissue in humans: detection and functional analysis using PET (positron emission tomography), MRI (magnetic resonance imaging), and DECT (dual energy computed tomography).

    PubMed

    Borga, Magnus; Virtanen, Kirsi A; Romu, Thobias; Leinhard, Olof Dahlqvist; Persson, Anders; Nuutila, Pirjo; Enerbäck, Sven

    2014-01-01

    If the beneficial effects of brown adipose tissue (BAT) on whole body metabolism, as observed in nonhuman experimental models, are to be translated to humans, tools that accurately measure how BAT influences human metabolism will be required. This chapter discusses such techniques, how they can be used, what they can measure and also some of their limitations. The focus is on detection and functional analysis of human BAT and how this can be facilitated by applying advanced imaging technology such as positron emission tomography, magnetic resonance imaging, and dual energy computed tomography. © 2014 Elsevier Inc. All rights reserved.

  19. [Differentiation of mesenchymal stem cells of adipose tissue].

    PubMed

    Salyutin, R V; Zapohlska, K M; Palyanytsya, S S; Sirman, V M; Sokolov, M F

    2015-03-01

    Experimental investigation were conducted with the objective to determine a stem cells, capacity to differentiate in adipogenic direction, if they were obtained from adipose tissue. The investigation results have witnessed, that the cells, obtained from adipose tissue, are capable for a tissue-speciphic differentiation in osteogenic, chondrogenic, and, principally--in adipogenic direction, what confirms a multypotent nature of mesenchymal stem cells of adipose tissue. Adipose tissue constitutes an alternative to the bone marrow, as a source of multipotent mesenchymal stem cells, which may be applied in further investigations, concerning determination of their defense possibility for the transplanted autologous adipose tissue from the tissue resorption, made in a lipophiling way.

  20. Osteopontin: Relation between Adipose Tissue and Bone Homeostasis

    PubMed Central

    Messina, Antonietta; Monda, Vincenzo; Viggiano, Emanuela; Valenzano, Anna; Esposito, Teresa; Cibelli, Giuseppe

    2017-01-01

    Osteopontin (OPN) is a multifunctional protein mainly associated with bone metabolism and remodeling. Besides its physiological functions, OPN is implicated in the pathogenesis of a variety of disease states, such as obesity and osteoporosis. Importantly, during the last decades obesity and osteoporosis have become among the main threats to health worldwide. Because OPN is a protein principally expressed in cells with multifaceted effects on bone morphogenesis and remodeling and because it seems to be one of the most overexpressed genes in the adipose tissue of the obese contributing to osteoporosis, this mini review will highlight recent insights about relation between adipose tissue and bone homeostasis. PMID:28194185

  1. Laminin α4 Deficient Mice Exhibit Decreased Capacity for Adipose Tissue Expansion and Weight Gain

    PubMed Central

    Movérare-Skrtic, Sofia; Kortesmaa, Jarkko; Soininen, Raija; Bergström, Göran; Ohlsson, Claes; Chong, Li Yen; Rozell, Björn; Emont, Margo; Cohen, Ronald N.; Brey, Eric M.; Tryggvason, Karl

    2014-01-01

    Obesity is a global epidemic that contributes to the increasing medical burdens related to type 2 diabetes, cardiovascular disease and cancer. A better understanding of the mechanisms regulating adipose tissue expansion could lead to therapeutics that eliminate or reduce obesity-associated morbidity and mortality. The extracellular matrix (ECM) has been shown to regulate the development and function of numerous tissues and organs. However, there is little understanding of its function in adipose tissue. In this manuscript we describe the role of laminin α4, a specialized ECM protein surrounding adipocytes, on weight gain and adipose tissue function. Adipose tissue accumulation, lipogenesis, and structure were examined in mice with a null mutation of the laminin α4 gene (Lama4−/−) and compared to wild-type (Lama4+/+) control animals. Lama4−/− mice exhibited reduced weight gain in response to both age and high fat diet. Interestingly, the mice had decreased adipose tissue mass and altered lipogenesis in a depot-specific manner. In particular, epididymal adipose tissue mass was specifically decreased in knock-out mice, and there was also a defect in lipogenesis in this depot as well. In contrast, no such differences were observed in subcutaneous adipose tissue at 14 weeks. The results suggest that laminin α4 influences adipose tissue structure and function in a depot-specific manner. Alterations in laminin composition offers insight into the roll the ECM potentially plays in modulating cellular behavior in adipose tissue expansion. PMID:25310607

  2. Betaine improved adipose tissue function in mice fed a high-fat diet: a mechanism for hepatoprotective effect of betaine in nonalcoholic fatty liver disease

    PubMed Central

    Wang, Zhigang; Yao, Tong; Pini, Maria; Zhou, Zhanxiang; Fantuzzi, Giamila

    2010-01-01

    -induced endoplasmic reticulum stress response in adipose tissue as shown by attenuated glucose-regulated protein 78/C/EBP homologous protein (CHOP) protein abundance and c-Jun NH2-terminal kinase activation. Our findings suggest that betaine might serve as a safe and efficacious therapeutic tool for NAFLD by improving adipose tissue function. PMID:20203061

  3. Betaine improved adipose tissue function in mice fed a high-fat diet: a mechanism for hepatoprotective effect of betaine in nonalcoholic fatty liver disease.

    PubMed

    Wang, Zhigang; Yao, Tong; Pini, Maria; Zhou, Zhanxiang; Fantuzzi, Giamila; Song, Zhenyuan

    2010-05-01

    -induced endoplasmic reticulum stress response in adipose tissue as shown by attenuated glucose-regulated protein 78/C/EBP homologous protein (CHOP) protein abundance and c-Jun NH(2)-terminal kinase activation. Our findings suggest that betaine might serve as a safe and efficacious therapeutic tool for NAFLD by improving adipose tissue function.

  4. Myocardial regeneration potential of adipose tissue-derived stem cells

    SciTech Connect

    Bai, Xiaowen; Alt, Eckhard

    2010-10-22

    Research highlights: {yields} Various tissue resident stem cells are receiving tremendous attention from basic scientists and clinicians and hold great promise for myocardial regeneration. {yields} For practical reasons, human adipose tissue-derived stem cells are attractive stem cells for future clinical application in repairing damaged myocardium. {yields} This review summarizes the characteristics of cultured and freshly isolated stem cells obtained from adipose tissue, their myocardial regeneration potential and the, underlying mechanisms, and safety issues. -- Abstract: Various tissue resident stem cells are receiving attention from basic scientists and clinicians as they hold promise for myocardial regeneration. For practical reasons, adipose tissue-derived stem cells (ASCs) are attractive cells for clinical application in repairing damaged myocardium based on the following advantages: abundant adipose tissue in most patients and easy accessibility with minimally invasive lipoaspiration procedure. Several recent studies have demonstrated that both cultured and freshly isolated ASCs could improve cardiac function in animal model of myocardial infarction. The mechanisms underlying the beneficial effect of ASCs on myocardial regeneration are not fully understood. Growing evidence indicates that transplantation of ASCs improve cardiac function via the differentiation into cardiomyocytes and vascular cells, and through paracrine pathways. Paracrine factors secreted by injected ASCs enhance angiogenesis, reduce cell apoptosis rates, and promote neuron sprouts in damaged myocardium. In addition, Injection of ASCs increases electrical stability of the injured heart. Furthermore, there are no reported cases of arrhythmia or tumorigenesis in any studies regarding myocardial regeneration with ASCs. This review summarizes the characteristics of both cultured and freshly isolated stem cells obtained from adipose tissue, their myocardial regeneration potential, and the

  5. Mice lacking GPR3 receptors display late-onset obese phenotype due to impaired thermogenic function in brown adipose tissue

    PubMed Central

    Godlewski, Grzegorz; Jourdan, Tony; Szanda, Gergő; Tam, Joseph; Resat Cinar; Harvey-White, Judith; Liu, Jie; Mukhopadhyay, Bani; Pacher, Pál; Ming Mo, Fong; Osei-Hyiaman, Douglas; George Kunos

    2015-01-01

    We report an unexpected link between aging, thermogenesis and weight gain via the orphan G protein-coupled receptor GPR3. Mice lacking GPR3 and maintained on normal chow had similar body weights during their first 5 months of life, but gained considerably more weight thereafter and displayed reduced total energy expenditure and lower core body temperature. By the age of 5 months GPR3 KO mice already had lower thermogenic gene expression and uncoupling protein 1 protein level and showed impaired glucose uptake into interscapular brown adipose tissue (iBAT) relative to WT littermates. These molecular deviations in iBAT of GPR3 KO mice preceded measurable differences in body weight and core body temperature at ambient conditions, but were coupled to a failure to maintain thermal homeostasis during acute cold challenge. At the same time, the same cold challenge caused a 17-fold increase in Gpr3 expression in iBAT of WT mice. Thus, GPR3 appears to have a key role in the thermogenic response of iBAT and may represent a new therapeutic target in age-related obesity. PMID:26455425

  6. Influence of exercise and perivascular adipose tissue on coronary artery vasomotor function in a familial hypercholesterolemic porcine atherosclerosis model

    PubMed Central

    Bunker, Aaron K.

    2010-01-01

    Our lab has shown that left circumflex coronary artery (LCX) perivascular adipose tissue (PAT) blunts endothelin-1 (ET-1)-induced maximal contractions in normal pigs on low- and high-fat diets. Other studies report that PAT exerts anticontractile effects on agonist-induced arterial contraction via release of a relaxing factor that acts on the underlying vasculature. The purpose of this study was to test the hypotheses that PAT blunts LCX contraction in familial hypercholesterolemic pigs and that exercise training (Ex) augments this anticontractile effect. Male familial hypercholesterolemic pigs were divided into Ex (n = 13) and sedentary (Sed) (n = 15) groups. LCX reactivity to angiotensin II (ANG II), bradykinin (BK), ET-1, and sodium nitroprusside (SNP) was evaluated in vitro with intact or removed PAT in Sed and Ex familial hypercholesterolemic pigs. LCX relaxation induced by BK and SNP was not altered by Ex or PAT removal. LCX contractions stimulated by ANG II and ET-1 were not significantly altered by Ex or PAT removal across doses; however, Ex did act to significantly reduce ET-1 maximal contractions in familial hypercholesterolemic pig LCX compared with Sed familial hypercholesterolemic pig LCX, independent of PAT (P < 0.05). We conclude that LCX PAT in Sed and Ex familial hypercholesterolemic pigs exerts no substantial anticontractile influence over LCX vasomotor responses to endogenous constrictors such as ANG II and ET-1. Our results suggest that exercise training significantly reduces familial hypercholesterolemic pig LCX maximal contractile responses to the endogenous constrictor ET-1, independent of PAT. PMID:19959766

  7. Natural killer T cells in adipose tissue prevent insulin resistance

    PubMed Central

    Schipper, Henk S.; Rakhshandehroo, Maryam; van de Graaf, Stan F.J.; Venken, Koen; Koppen, Arjen; Stienstra, Rinke; Prop, Serge; Meerding, Jenny; Hamers, Nicole; Besra, Gurdyal; Boon, Louis; Nieuwenhuis, Edward E.S.; Elewaut, Dirk; Prakken, Berent; Kersten, Sander; Boes, Marianne; Kalkhoven, Eric

    2012-01-01

    Lipid overload and adipocyte dysfunction are key to the development of insulin resistance and can be induced by a high-fat diet. CD1d-restricted invariant natural killer T (iNKT) cells have been proposed as mediators between lipid overload and insulin resistance, but recent studies found decreased iNKT cell numbers and marginal effects of iNKT cell depletion on insulin resistance under high-fat diet conditions. Here, we focused on the role of iNKT cells under normal conditions. We showed that iNKT cell–deficient mice on a low-fat diet, considered a normal diet for mice, displayed a distinctive insulin resistance phenotype without overt adipose tissue inflammation. Insulin resistance was characterized by adipocyte dysfunction, including adipocyte hypertrophy, increased leptin, and decreased adiponectin levels. The lack of liver abnormalities in CD1d-null mice together with the enrichment of CD1d-restricted iNKT cells in both mouse and human adipose tissue indicated a specific role for adipose tissue–resident iNKT cells in the development of insulin resistance. Strikingly, iNKT cell function was directly modulated by adipocytes, which acted as lipid antigen-presenting cells in a CD1d-mediated fashion. Based on these findings, we propose that, especially under low-fat diet conditions, adipose tissue–resident iNKT cells maintain healthy adipose tissue through direct interplay with adipocytes and prevent insulin resistance. PMID:22863618

  8. Clinical Investigation Into Plasma Neutrophil Gelatinase-Associated Lipocalin and Body Adipose Tissue Associated With Remaining Renal Function in Living Kidney Donor.

    PubMed

    Lee, H H; Yoon, Y E; Kang, S K; Bravo, R C C; Alabandi, A M; Huh, K H; Kim, M S; Kim, S I; Kim, Y S; Han, W K

    2017-06-01

    Plasma neutrophil gelatinase-associated lipocalin (pNGAL) is known to increase in proportion to the degree and period of renal damage. This study aimed to evaluate the clinical relevance of pNGAL and body adipose tissue to remaining renal function in living kidney donors. Between July 2013 and February 2015, 75 live kidney donors were enrolled. Visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and VAT/SAT ratio were measured in preoperative CT scan which performed before surgery. We analyzed the correlation among the variables (VAT, SAT, and VAT/SAT ratio), eGFR and pNGAL. ΔpNGAL-max(=Maximum pNGAL-measures), ΔpNGAL-min(=Minimum pNGAL-measures), ΔeGFR-max(=Maximum eGFR-measures) and ΔeGFR-min(=Minimum eGFR-measures) were also analyzed. The highest value of pNGAL (207.46 ± 76 ng/mL) was observed on postoperative day 7, and the lowest value of eGFR (57.52 ± 11.20 mL/min/1.73 m(2)) was also measured on postoperative day 7. A significant correlation was found between ΔpNGAL, VAT, and VAT-to-SAT ratio. Moreover, a significant correlation between ΔpNGALmin and ΔeGFRmin was revealed. Also, VAT-to-SAT ratio was correlated with ΔeGFRmin during the all of the follow-up periods, and it was also correlated with ΔpNGALmin until postoperative day 3. There was a correlation between the elevation of pNGAL until postoperative day 5 and the decrease of eGFR after living donor nephrectomy. VAT-to-SAT ratio had a significant correlation with both ΔpNGALmin and eGFRmin. Given the metabolism of pNGAL, the increase of pNGAL seemed to be affected as a consequence of body adipose tissue. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Brain-adipose tissue cross talk.

    PubMed

    Bartness, Timothy J; Kay Song, C; Shi, Haifei; Bowers, Robert R; Foster, Michelle T

    2005-02-01

    While investigating the reversible seasonal obesity of Siberian hamsters, direct sympathetic nervous system (SNS) postganglionic innervation of white adipose tissue (WAT) has been demonstrated using anterograde and retrograde tract tracers. The primary function of this innervation is lipid mobilization. The brain SNS outflow to WAT has been defined using the pseudorabies virus (PRV), a retrograde transneuronal tract tracer. These PRV-labelled SNS outflow neurons are extensively co-localized with melanocortin-4 receptor mRNA, which, combined with functional data, suggests their involvement in lipolysis. The SNS innervation of WAT also regulates fat cell number, as noradrenaline inhibits and WAT denervation stimulates fat cell proliferation in vitro and in vivo respectively. The sensory innervation of WAT has been demonstrated by retrograde tract tracing, electrophysiological recording and labelling of the sensory-associated neuropeptide calcitonin gene-related peptide in WAT. Local injections of the sensory nerve neurotoxin capsaicin into WAT selectively destroy this innervation. Just as surgical removal of WAT pads triggers compensatory increases in lipid accretion by non-excised WAT depots, capsaicin-induced sensory denervation triggers increases in lipid accretion of non-capsaicin-injected WAT depots, suggesting that these nerves convey information about body fat levels to the brain. Finally, parasympathetic nervous system innervation of WAT has been suggested, but the recent finding of no WAT immunoreactivity for the possible parasympathetic marker vesicular acetylcholine transporter (VAChT) argues against this claim. Collectively, these data suggest several roles for efferent and afferent neural innervation of WAT in body fat regulation.

  10. Benefits of healthy adipose tissue in the treatment of diabetes.

    PubMed

    Gunawardana, Subhadra C

    2014-08-15

    The major malfunction in diabetes mellitus is severe perturbation of glucose homeostasis caused by deficiency of insulin. Insulin deficiency is either absolute due to destruction or failure of pancreatic β cells, or relative due to decreased sensitivity of peripheral tissues to insulin. The primary lesion being related to insulin, treatments for diabetes focus on insulin replacement and/or increasing sensitivity to insulin. These therapies have their own limitations and complications, some of which can be life-threatening. For example, exogenous insulin administration can lead to fatal hypoglycemic episodes; islet/pancreas transplantation requires life-long immunosuppressive therapy; and anti-diabetic drugs have dangerous side effects including edema, heart failure and lactic acidosis. Thus the need remains for better safer long term treatments for diabetes. The ultimate goal in treating diabetes is to re-establish glucose homeostasis, preferably through endogenously generated hormones. Recent studies increasingly show that extra-pancreatic hormones, particularly those arising from adipose tissue, can compensate for insulin, or entirely replace the function of insulin under appropriate circumstances. Adipose tissue is a versatile endocrine organ that secretes a variety of hormones with far-reaching effects on overall metabolism. While unhealthy adipose tissue can exacerbate diabetes through limiting circulation and secreting of pro-inflammatory cytokines, healthy uninflamed adipose tissue secretes beneficial adipokines with hypoglycemic and anti-inflammatory properties, which can complement and/or compensate for the function of insulin. Administration of specific adipokines is known to alleviate both type 1 and 2 diabetes, and leptin mono-therapy is reported to reverse type 1 diabetes independent of insulin. Although specific adipokines may correct diabetes, administration of individual adipokines still carries risks similar to those of insulin monotherapy. Thus a

  11. Nutritional regulation of lipid metabolism in human adipose tissue.

    PubMed

    Coppack, S W; Patel, J N; Lawrence, V J

    2001-01-01

    Pfeiffer and colleagues years ago pointed out that different distributions and amounts of adipose tissue are associated with abnormalities of lipolysis and lipoprotein metabolism. Adipose tissue has several crucial roles including (i) mobilization from stores of fatty acids as an energy source, (ii) catabolism of lipoproteins such as very-low-density lipoprotein and (iii) synthesis and release of hormonal signals such as leptin and interleukin-6. These adipose tissue actions are crucially regulated by nutrition. The review considers the existence of metabolic pathways and modes of regulation within adipose tissue, and how such metabolic activity can be quantitated in humans. Nutrition can influence adipose tissue at several 'levels'. Firstly the level of obesity or malnutrition has important effects on many aspects of adipose tissue metabolism. Secondly short-term overfeeding, underfeeding and exercise have major impacts on adipose tissue behaviour. Lastly, specific nutrients are capable of regulating adipose tissue metabolism. Recently there have been considerable advances in understanding adipose tissue metabolism and in particular its regulation. This review discusses the behaviour of adipose tissue under various nutritional conditions. There is then a review of recent work examining the ways in which nutritional influences act via intra-cellular mechanisms, insulin and the sympathetic innervation of adipose tissue.

  12. Oestrone sulphate, adipose tissue, and breast cancer.

    PubMed

    Hawkins, R A; Thomson, M L; Killen, E

    1985-01-01

    Oestrone sulphate, the oestrogen in highest concentration in the plasma, may play a role in the induction and growth of breast cancers. By enzymolysis and radioimmunoassay, oestrone sulphate concentrations were measured in 3 biological fluids. High concentrations of the conjugate (up to 775 nmol/l) were detected in breast cyst fluids from some premenopausal women, the concentrations in blood plasma (0.91-4.45 nmol/l) being much lower. Concentrations in the plasmas from postmenopausal women with (0.23-4.63 nmol/l) or without (0.18-1.27 nmol/l) breast cancer were still lower. Oestrone sulphate concentration in cow's milk or cream (0.49-0.67 nmol/l) was also low: dietary intake in these fluids is probably of little consequence. The capacity of breast tissues for hydrolysis of oestrone sulphate was examined in two ways: In tissue slices incubated with 85 pM (3H) oestrone sulphate solution at 37 degrees C, cancers (131-412 fmol/g tissue/hr) and adipose tissues (23-132 fmol/g tissue/hr) hydrolysed significantly more sulphate than did benign tissues (1-36 fmol/g tissue/hr). In tissue homogenates incubated with 5-25 microM [3H] oestrone sulphate at 37 degrees much higher capacities for hydrolysis (nmol/g tissue/hr) were demonstrated with a Km of 2-16.5 microM: cancers (34-394) and benign tissues (9-485) had significantly higher sulphatase activities than adipose tissues (9-39). On a protein basis, however, the sulphatase activities in the 3 tissues were comparable. It is concluded that oestrone sulphate is present in breast cysts and blood plasma and that in vitro, the conjugated hormone can be hydrolysed by breast tissues. The biological significance of these findings in vivo remains to be established.

  13. Enzymatic intracrine regulation of white adipose tissue

    PubMed Central

    DiSilvestro, David; Petrosino, Jennifer; Aldoori, Ayat; Melgar-Bermudez, Emiliano; Wells, Alexandra; Ziouzenkova, Ouliana

    2015-01-01

    Abdominal fat formation has become a permanent risk factor for metabolic syndrome and various cancers in one-third of the world's population of obese and even lean patients. Formation of abdominal fat involves additional mechanisms beyond an imbalance in energy intake and expenditure, which explains systemic obesity. In this review, we briefly summarized autonomous regulatory circuits that locally produce hormones from inactive precursors or nutrients for intra-/auto-/paracrine signaling in white adipose depots. Enzymatic pathways activating steroid and thyroid hormones in adipose depots were compared with enzymatic production of retinoic acid from vitamin A. We discussed the role of intracrine circuits in fat-depot functions and strategies to reduce abdominal adiposity through thermogenic adipocytes with interrupted generation of retinoic acid. PMID:25390015

  14. Catechol-Functionalized Hyaluronic Acid Hydrogels Enhance Angiogenesis and Osteogenesis of Human Adipose-Derived Stem Cells in Critical Tissue Defects.

    PubMed

    Park, Hyun-Ji; Jin, Yoonhee; Shin, Jisoo; Yang, Kisuk; Lee, Changhyun; Yang, Hee Seok; Cho, Seung-Woo

    2016-06-13

    Over the last few decades, stem cell therapies have been highlighted for their potential to heal damaged tissue and aid in tissue reconstruction. However, materials used to deliver and support implanted cells often display limited efficacy, which has resulted in delaying translation of stem cell therapies into the clinic. In our previous work, we developed a mussel-inspired, catechol-functionalized hyaluronic acid (HA-CA) hydrogel that enabled effective cell transplantation due to its improved biocompatibility and strong tissue adhesiveness. The present study was performed to further expand the utility of HA-CA hydrogels for use in stem cell therapies to treat more clinically relevant tissue defect models. Specifically, we utilized HA-CA hydrogels to potentiate stem cell-mediated angiogenesis and osteogenesis in two tissue defect models: critical limb ischemia and critical-sized calvarial bone defect. HA-CA hydrogels were found to be less cytotoxic to human adipose-derived stem cells (hADSCs) in vitro compared to conventional photopolymerized HA hydrogels. HA-CA hydrogels also retained the angiogenic functionality of hADSCs and supported osteogenic differentiation of hADSCs. Because of their superior tissue adhesiveness, HA-CA hydrogels were able to mediate efficient engraftment of hADSCs into the defect regions. When compared to photopolymerized HA hydrogels, HA-CA hydrogels significantly enhanced hADSC-mediated therapeutic angiogenesis (promoted capillary/arteriole formation, improved vascular perfusion, attenuated ischemic muscle degeneration/fibrosis, and reduced limb amputation) and bone reconstruction (mineralized bone formation, enhanced osteogenic marker expression, and collagen deposition). This study proves the feasibility of using bioinspired HA-CA hydrogels as functional biomaterials for improved tissue regeneration in critical tissue defects.

  15. Increased adipose tissue aromatase activity improves insulin sensitivity and reduces adipose tissue inflammation in male mice.

    PubMed

    Ohlsson, Claes; Hammarstedt, Ann; Vandenput, Liesbeth; Saarinen, Niina; Ryberg, Henrik; Windahl, Sara H; Farman, Helen H; Jansson, John-Olov; Movérare-Skrtic, Sofia; Smith, Ulf; Zhang, Fu-Ping; Poutanen, Matti; Hedjazifar, Shahram; Sjögren, Klara

    2017-10-01

    Females are, in general, more insulin sensitive than males. To investigate whether this is a direct effect of sex-steroids (SS) in white adipose tissue (WAT), we developed a male mouse model overexpressing the aromatase enzyme, converting testosterone (T) to estradiol (E2), specifically in WAT (Ap2-arom mice). Adipose tissue E2 levels were increased while circulating SS levels were unaffected in male Ap2-arom mice. Importantly, male Ap2-arom mice were more insulin sensitive compared with WT mice and exhibited increased serum adiponectin levels and upregulated expression of Glut4 and Irs1 in WAT. The expression of markers of macrophages and immune cell infiltration was markedly decreased in WAT of male Ap2-arom mice. The adipogenesis was enhanced in male Ap2-arom mice, supported by elevated Pparg expression in WAT and enhanced differentiation of preadipocyte into mature adipocytes. In summary, increased adipose tissue aromatase activity reduces adipose tissue inflammation and improves insulin sensitivity in male mice. We propose that estrogen increases insulin sensitivity via a local effect in WAT on adiponectin expression, adipose tissue inflammation, and adipogenesis. Copyright © 2017 the American Physiological Society.

  16. Adipose Tissue as a Site of Toxin Accumulation.

    PubMed

    Jackson, Erin; Shoemaker, Robin; Larian, Nika; Cassis, Lisa

    2017-09-12

    We examine the role of adipose tissue, typically considered an energy storage site, as a potential site of toxicant accumulation. Although the production of most persistent organic pollutants (POPs) was banned years ago, these toxicants persist in the environment due to their resistance to biodegradation and widespread distribution in various environmental forms (e.g., vapor, sediment, and water). As a result, human exposure to these toxicants is inevitable. Largely due to their lipophilicity, POPs bioaccumulate in adipose tissue, resulting in greater body burdens of these environmental toxicants with obesity. POPs of major concern include polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and furans (PCDDs/PCDFs), and polybrominated biphenyls and diphenyl ethers (PBBs/PBDEs), among other organic compounds. In this review, we (i) highlight the physical characteristics of toxicants that enable them to partition into and remain stored in adipose tissue, (ii) discuss the specific mechanisms of action by which these toxicants act to influence adipocyte function, and (iii) review associations between POP exposures and the development of obesity and diabetes. An area of controversy relates to the relative potential beneficial versus hazardous health effects of toxicant sequestration in adipose tissue. © 2017 American Physiological Society. Compr Physiol 7:1085-1135, 2017. Copyright © 2017 John Wiley & Sons, Inc.

  17. Pulsed electric breakdown in adipose tissue

    NASA Astrophysics Data System (ADS)

    Kolb, Juergen F.; Scully, Noah; Paithankar, Dilip

    2011-08-01

    High voltage pulses of sub-microsecond duration can instigate electrical breakdown in adipose tissue, which is followed by a spark discharge. Breakdown voltages are generally lower than observed for purified lipids but higher than for air. Development of breakdown for the repetitive application of pulses resembles a gradual and stochastic process as reported for partial discharges in solid dielectrics. The inflicted tissue damage itself is confined to the gap between electrodes, providing a method to use spark discharges as a precise surgical technique.

  18. Berardinelli-Seip Congenital Lipodystrophy 2/Seipin Is Not Required for Brown Adipogenesis but Regulates Brown Adipose Tissue Development and Function

    PubMed Central

    Zhou, Hongyi; Black, Stephen M.; Benson, Tyler W.; Weintraub, Neal L.

    2016-01-01

    Brown adipose tissue (BAT) plays a unique role in regulating whole-body energy homeostasis by dissipating energy through thermogenic uncoupling. Berardinelli-Seip congenital lipodystrophy (BSCL) type 2 (BSCL2; also known as seipin) is a lipodystrophy-associated endoplasmic reticulum membrane protein essential for white adipocyte differentiation. Whether BSCL2 directly participates in brown adipocyte differentiation, development, and function, however, is unknown. We show that BSCL2 expression is increased during brown adipocyte differentiation. Its deletion does not impair the classic brown adipogenic program but rather induces premature activation of differentiating brown adipocytes through cyclic AMP (cAMP)/protein kinase A (PKA)-mediated lipolysis and fatty acid and glucose oxidation, as well as uncoupling. cAMP/PKA signaling is physiologically activated during neonatal BAT development in wild-type mice and greatly potentiated in mice with genetic deletion of Bscl2 in brown progenitor cells, leading to reduced BAT mass and lipid content during neonatal brown fat formation. However, prolonged overactivation of cAMP/PKA signaling during BAT development ultimately causes apoptosis of brown adipocytes through inflammation, resulting in BAT atrophy and increased overall adiposity in adult mice. These findings reveal a key cell-autonomous role for BSCL2 in controlling BAT mass/activity and provide novel insights into therapeutic strategies targeting cAMP/PKA signaling to regulate brown adipocyte function, viability, and metabolic homeostasis. PMID:27185876

  19. Paracrine and intracrine contributions of androgens and estrogens to adipose tissue biology: physiopathological aspects.

    PubMed

    Waraich, Rizwana S; Mauvais-Jarvis, Franck

    2013-08-01

    In mammals, the male and female hormones androgen and estrogen act as endocrine regulators of energy metabolism. However, adipose tissue is also a site of androgen and estrogen synthesis; androgens convert to estrogens in these tissues, and adipose tissue is also a reservoir of steroids that act locally in a paracrine and intracrine manner. Thus, in adipose tissue, the local output of sex hormones is more complex than would be suggested by routine measurement of serum hormone concentrations. This review integrates studies on the effects of androgens and estrogens in the developmental programming of adipose tissue function in early life and addresses the contributions of local androgen and estrogen metabolism on adipose tissue function in adults.

  20. Exercise Effects on White Adipose Tissue: Beiging and Metabolic Adaptations.

    PubMed

    Stanford, Kristin I; Middelbeek, Roeland J W; Goodyear, Laurie J

    2015-07-01

    Regular physical activity and exercise training have long been known to cause adaptations to white adipose tissue (WAT), including decreases in cell size and lipid content and increases in mitochondrial proteins. In this article, we discuss recent studies that have investigated the effects of exercise training on mitochondrial function, the "beiging" of WAT, regulation of adipokines, metabolic effects of trained adipose tissue on systemic metabolism, and depot-specific responses to exercise training. The major WAT depots in the body are found in the visceral cavity (vWAT) and subcutaneously (scWAT). In rodent models, exercise training increases mitochondrial biogenesis and activity in both these adipose tissue depots. Exercise training also increases expression of the brown adipocyte marker uncoupling protein 1 (UCP1) in both adipose tissue depots, although these effects are much more pronounced in scWAT. Consistent with the increase in UCP1, exercise training increases the presence of brown-like adipocytes in scWAT, also known as browning or beiging. Training results in changes in the gene expression of thousands of scWAT genes and an altered adipokine profile in both scWAT and vWAT. Transplantation of trained scWAT in sedentary recipient mice results in striking improvements in skeletal muscle glucose uptake and whole-body metabolic homeostasis. Human and rodent exercise studies have indicated that exercise training can alter circulating adipokine concentration as well as adipokine expression in adipose tissue. Thus, the profound changes to WAT in response to exercise training may be part of the mechanism by which exercise improves whole-body metabolic health. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  1. Exercise Effects on White Adipose Tissue: Beiging and Metabolic Adaptations

    PubMed Central

    Stanford, Kristin I.; Middelbeek, Roeland J.W.

    2015-01-01

    Regular physical activity and exercise training have long been known to cause adaptations to white adipose tissue (WAT), including decreases in cell size and lipid content and increases in mitochondrial proteins. In this article, we discuss recent studies that have investigated the effects of exercise training on mitochondrial function, the “beiging” of WAT, regulation of adipokines, metabolic effects of trained adipose tissue on systemic metabolism, and depot-specific responses to exercise training. The major WAT depots in the body are found in the visceral cavity (vWAT) and subcutaneously (scWAT). In rodent models, exercise training increases mitochondrial biogenesis and activity in both these adipose tissue depots. Exercise training also increases expression of the brown adipocyte marker uncoupling protein 1 (UCP1) in both adipose tissue depots, although these effects are much more pronounced in scWAT. Consistent with the increase in UCP1, exercise training increases the presence of brown-like adipocytes in scWAT, also known as browning or beiging. Training results in changes in the gene expression of thousands of scWAT genes and an altered adipokine profile in both scWAT and vWAT. Transplantation of trained scWAT in sedentary recipient mice results in striking improvements in skeletal muscle glucose uptake and whole-body metabolic homeostasis. Human and rodent exercise studies have indicated that exercise training can alter circulating adipokine concentration as well as adipokine expression in adipose tissue. Thus, the profound changes to WAT in response to exercise training may be part of the mechanism by which exercise improves whole-body metabolic health. PMID:26050668

  2. Systems biology approach to identify alterations in the stem cell reservoir of subcutaneous adipose tissue in a rat model of diabetes: effects on differentiation potential and function.

    PubMed

    Ferrer-Lorente, Raquel; Bejar, Maria Teresa; Tous, Monica; Vilahur, Gemma; Badimon, Lina

    2014-01-01

    Autologous progenitor cells represent a promising option for regenerative cell-based therapies. Nevertheless, it has been shown that ageing and cardiovascular risk factors such as diabetes affect circulating endothelial and bone marrow-derived progenitor cells, limiting their therapeutic potential. However, their impact on other stem cell populations remains unclear. We therefore investigated the effects of diabetes on adipose-derived stem cells (ASCs) and whether these effects might limit the therapeutic potential of autologous ASCs. A systems biology approach was used to analyse the expression of genes related to stem cell identification in subcutaneous adipose tissue (SAT), the stromal vascular fraction and isolated ASCs from Zucker diabetic fatty rats and their non-diabetic controls. An additional model of type 2 diabetes without obesity was also investigated. Bioinformatic approaches were used to investigate the biological significance of these changes. In addition, functional studies on cell viability and differentiation potential were performed. Widespread downregulation of mesenchymal stem cell markers was observed in SAT of diabetic rats. Gene expression and in silico analysis revealed a significant effect on molecules involved in the maintenance of pluripotency and self-renewal, and on the alteration of main signalling pathways important for stem cell maintenance. The viability and differentiation potential of ASCs from diabetic rats was impaired in in vitro models and in in vivo angiogenesis. The impact of type 2 diabetes on ASCs might compromise the efficiency of spontaneous self-repair and direct autologous stem cell therapy.

  3. 'Browning' the cardiac and peri-vascular adipose tissues to modulate cardiovascular risk.

    PubMed

    Aldiss, Peter; Davies, Graeme; Woods, Rachel; Budge, Helen; Sacks, Harold S; Symonds, Michael E

    2017-02-01

    Excess visceral adiposity, in particular that located adjacent to the heart and coronary arteries is associated with increased cardiovascular risk. In the pathophysiological state, dysfunctional adipose tissue secretes an array of factors modulating vascular function and driving atherogenesis. Conversely, brown and beige adipose tissues utilise glucose and lipids to generate heat and are associated with improved cardiometabolic health. The cardiac and thoracic perivascular adipose tissues are now understood to be composed of brown adipose tissue in the healthy state and undergo a brown-to-white transition i.e. during obesity which may be a driving factor of cardiovascular disease. In this review we discuss the risks of excess cardiac and vascular adiposity and potential mechanisms by which restoring the brown phenotype i.e. "re-browning" could potentially be achieved in clinically relevant populations.

  4. Exercise differentially affects metabolic functions and white adipose tissue in female letrozole- and dihydrotestosterone-induced mouse models of polycystic ovary syndrome.

    PubMed

    Marcondes, Rodrigo R; Maliqueo, Manuel; Fornes, Romina; Benrick, Anna; Hu, Min; Ivarsson, Niklas; Carlström, Mattias; Cushman, Samuel W; Stenkula, Karin G; Maciel, Gustavo A R; Stener-Victorin, Elisabet

    2017-03-24

    Here we hypothesized that exercise in dihydrotestosterone (DHT) or letrozole (LET)-induced polycystic ovary syndrome mouse models improves impaired insulin and glucose metabolism, adipose tissue morphology, and expression of genes related to adipogenesis, lipid metabolism, Notch pathway and browning in inguinal and mesenteric fat. DHT-exposed mice had increased body weight, increased number of large mesenteric adipocytes. LET-exposed mice displayed increased body weight and fat mass, decreased insulin sensitivity, increased frequency of small adipocytes and increased expression of genes related to lipolysis in mesenteric fat. In both models, exercise decreased fat mass and inguinal and mesenteric adipose tissue expression of Notch pathway genes, and restored altered mesenteric adipocytes morphology. In conclusion, exercise restored mesenteric adipocytes morphology in DHT- and LET-exposed mice, and insulin sensitivity and mesenteric expression of lipolysis-related genes in LET-exposed mice. Benefits could be explained by downregulation of Notch, and modulation of browning and lipolysis pathways in the adipose tissue.

  5. IFATS Collection: Human Adipose Tissue-Derived Stem Cells Induce Angiogenesis and Nerve Sprouting Following Myocardial Infarction, in Conjunction with Potent Preservation of Cardiac Function

    PubMed Central

    Cai, Liying; Johnstone, Brian H.; Cook, Todd G.; Tan, Jian; Fishbein, Michael C.; Chen, Peng-Sheng; March, Keith L.

    2010-01-01

    The administration of therapeutic cell types, such as stem and progenitor cells, has gained much interest for the limitation or repair of tissue damage caused by a variety of insults. However, it is still uncertain whether the morphological and functional benefits are mediated predominantly via cell differentiation or paracrine mechanisms. Here, we assessed the extent and mechanisms of adipose-derived stromal/stem cells (ASC)-dependent tissue repair in the context of acute myocardial infarction. Human ASCs in saline or saline alone was injected into the peri-infarct region in athymic rats following left anterior descending (LAD) coronary artery ligation. Cardiac function and structure were evaluated by serial echocardiography and histology. ASC-treated rats consistently exhibited better cardiac function, by all measures, than control rats 1 month following LAD occlusion. Left ventricular (LV) ejection fraction and fractional shortening were improved in the ASC group, whereas LV remodeling and dilation were limited in the ASC group compared with the saline control group. Anterior wall thinning was also attenuated by ASC treatment, and post-mortem histological analysis demonstrated reduced fibrosis in ASC-treated hearts, as well as increased peri-infarct density of both arterioles and nerve sprouts. Human ASCs were persistent at 1 month in the peri-infarct region, but they were not observed to exhibit significant cardiomyocyte differentiation. Human ASCs preserve heart function and augment local angiogenesis and cardiac nerve sprouting following myocardial infarction predominantly by the provision of beneficial trophic factors. PMID:18772313

  6. The Interplay Between Sex, Ethnicity, and Adipose Tissue Characteristics.

    PubMed

    Karastergiou, Kalypso

    2015-06-01

    The obesity epidemic in the USA affects disproportionately women and the ethnic minorities. On the other hand, female sex is traditionally associated with a favorable fat distribution preferentially in the subcutaneous depots of the lower body and with improved endocrine and metabolic function of the adipose tissue. However, these data are derived from predominantly non-Hispanic white populations. This review discusses fat distribution patterns in women of diverse ethnic backgrounds, together with data on the release of adipokines from adipose tissue in these populations. Very little information is available on how the metabolic function of the adipocyte differs depending on ethnicity. Thus, it becomes clear that future clinical and translational research should explicitly discuss and take into account the sex and ethnic background of the populations studied.

  7. Browning effects of (-)-epicatechin on adipocytes and white adipose tissue.

    PubMed

    Varela, Claudia Elena; Rodriguez, Alonso; Romero-Valdovinos, Mirza; Mendoza-Lorenzo, Patricia; Mansour, Christina; Ceballos, Guillermo; Villarreal, Francisco; Ramirez-Sanchez, Israel

    2017-09-15

    In this study, we demonstrate that (-)-epicatechin (Epi), a cacao flavanol, induces the browning of fat by promoting mitochondrial biogenesis, enhancing indicators of mitochondrial structure and function, increasing fatty acid metabolism and upregulating the expression of brown adipose tissue-specific proteins in a high-fat diet mouse model of obesity and in cultured human adipocytes. Epi treatment significantly improved mitochondrial function, as measured by citrate synthase activity, and also reduced protein acetylation of total and specific regulators in both adipose tissue and human adipocytes. Browning of fat via Epi was evidenced by the increased expression of key thermogenic genes, phosphorylation of upstream regulators of fatty acid oxidation, and reduced triglyceride levels. Properly designed clinical trials are needed to explore the potential of Epi as an agent that promotes the browning of fat. Copyright © 2017. Published by Elsevier B.V.

  8. Role of developmental transcription factors in white, brown and beige adipose tissues.

    PubMed

    Hilton, Catriona; Karpe, Fredrik; Pinnick, Katherine E

    2015-05-01

    In this review we discuss the role of developmental transcription factors in adipose tissue biology with a focus on how these developmental genes may contribute to regional variation in adipose tissue distribution and function. Regional, depot-specific, differences in lipid handling and signalling (lipolysis, lipid storage and adipokine/lipokine signalling) are important determinants of metabolic health. At a cellular level, preadipocytes removed from their original depot and cultured in vitro retain depot-specific functional properties, implying that these are intrinsic to the cells and not a function of their environment in situ. High throughput screening has identified a number of developmental transcription factors involved in embryological development, including members of the Homeobox and T-Box gene families, that are strongly differentially expressed between regional white adipose tissue depots and also between brown and white adipose tissue. However, the significance of depot-specific developmental signatures remains unclear. Developmental transcription factors determine body patterning during embryogenesis. The divergent developmental origins of regional adipose tissue depots may explain their differing functional characteristics. There is evidence from human genetics that developmental genes determine adipose tissue distribution: in GWAS studies a number of developmental genes have been identified as being correlated with anthropometric measures of adiposity and fat distribution. Additionally, compelling functional studies have recently implicated developmental genes in both white adipogenesis and the so-called 'browning' of white adipose tissue. Understanding the genetic and developmental pathways in adipose tissue may help uncover novel ways to intervene with the function of adipose tissue in order to promote health.

  9. Metabolic inflammation in inflammatory bowel disease: crosstalk between adipose tissue and bowel.

    PubMed

    Gonçalves, Pedro; Magro, Fernando; Martel, Fátima

    2015-02-01

    Epidemiological studies show that both the incidence of inflammatory bowel disease (IBD) and the proportion of people with obesity and/or obesity-associated metabolic syndrome increased markedly in developed countries during the past half century. Obesity is also associated with the development of more active IBD and requirement for hospitalization and with a decrease in the time span between diagnosis and surgery. Patients with IBD, especially Crohn's disease, present fat-wrapping or "creeping fat," which corresponds to ectopic adipose tissue extending from the mesenteric attachment and covering the majority of the small and large intestinal surface. Mesenteric adipose tissue in patients with IBD presents several morphological and functional alterations, e.g., it is more infiltrated with immune cells such as macrophages and T cells. All these lines of evidence clearly show an association between obesity, adipose tissue, and functional bowel disorders. In this review, we will show that the mesenteric adipose tissue and creeping fat are not innocent by standers but actively contribute to the intestinal and systemic inflammatory responses in patients with IBD. More specifically, we will review evidence showing that adipose tissue in IBD is associated with major alterations in the secretion of cytokines and adipokines involved in inflammatory process, in adipose tissue mesenchymal stem cells and adipogenesis, and in the interaction between adipose tissue and other intestinal components (immune, lymphatic, neuroendocrine, and intestinal epithelial systems). Collectively, these studies underline the importance of adipose tissue for the identification of novel therapeutic approaches for IBD.

  10. [The adipose tissue as a regulatory center of the metabolism].

    PubMed

    Fonseca-Alaniz, Miriam H; Takada, Julie; Alonso-Vale, Maria Isabel C; Lima, Fabio Bessa

    2006-04-01

    The recent progress in the research about the metabolic properties of the adipose tissue and the discovery of its ability to produce hormones that are very active in pathophysiologic as well as physiologic processes is rebuilding the concepts about its biology. Its involvement in conditions like obesity, type 2 diabetes mellitus, arterial hypertension, arteriosclerosis, dislipidemias and chronic and acute inflammatory processes indicate that the understanding of its functional capacities may contribute to improve the prognosis of those diseases whose prevalence increased in a preoccupying manner. Here we review some functional aspects of adipocytes, such as the metabolism, its influence on energy homeostasis, its endocrine ability and the adipogenesis, i.e., the potential of pre-adipocytes present in adipose tissue stroma to differentiate into new adipocytes and regenerate the tissue. In addition, we are including some studies on the relationship between the adipose tissue and the pineal gland, a new and poorly known, although, as will be seen, very promising aspect of adipocyte physiology together with its possible favorable repercussions to the therapy of the obesity related diseases.

  11. Androgenic Regulation of White Adipose Tissue-Prostate Cancer Interactions

    DTIC Science & Technology

    2012-05-01

    April 2012 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Androgenic Regulation of White Adipose Tissue -Prostate Cancer Interactions 5b. GRANT NUMBER...Floryk D, Kurosaka S, Tanimoto R, Yang G, Goltsov A, Park S, Thompson TC. Castration- induced changes in mouse epididymal white adipose tissue . Mol Cell...1. Floryk D, Kurosaka S, Tanimoto R, Yang G, Goltsov A, Park S, Thompson TC. Castration- induced changes in mouse epididymal white adipose tissue

  12. Hedgehog signalling in myeloid cells impacts on body weight, adipose tissue inflammation and glucose metabolism.

    PubMed

    Braune, Julia; Weyer, Ulrike; Matz-Soja, Madlen; Hobusch, Constance; Kern, Matthias; Kunath, Anne; Klöting, Nora; Kralisch, Susann; Blüher, Matthias; Gebhardt, Rolf; Zavros, Yana; Bechmann, Ingo; Gericke, Martin

    2017-05-01

    Recently, hedgehog (Hh) was identified as a crucial player in adipose tissue development and energy expenditure. Therefore, we tested whether Hh ligands are regulated in obesity. Further, we aimed at identifying potential target cells of Hh signalling and studied the functional impact of Hh signalling on adipose tissue inflammation and glucose metabolism. Hh ligands and receptors were analysed in adipose tissue or serum from lean and obese mice as well as in humans. To study the impact on adipose tissue inflammation and glucose metabolism, Hh signalling was specifically blocked in myeloid cells using a conditional knockout approach (Lys-Smo (-/-)). Desert Hh (DHH) and Indian Hh (IHH) are local Hh ligands, whereas Sonic Hh is not expressed in adipose tissue from mice or humans. In mice, obesity leads to a preferential upregulation of Hh ligands (Dhh) and signalling components (Ptch1, Smo and Gli1) in subcutaneous adipose tissue. Further, adipose tissue macrophages are Hh target cells owing to the expression of Hh receptors, such as Patched1 and 2. Conditional knockout of Smo (which encodes Smoothened, a mandatory Hh signalling component) in myeloid cells increases body weight and adipose tissue inflammation and attenuates glucose tolerance, suggesting an anti-inflammatory effect of Hh signalling. In humans, adipose tissue expression of DHH and serum IHH decrease with obesity and type 2 diabetes, which might be explained by the intake of metformin. Interestingly, metformin reduced Dhh and Ihh expression in mouse adipose tissue explants. Hh signalling in myeloid cells affects adipose tissue inflammation and glucose metabolism and may be a potential target to treat type 2 diabetes.

  13. Characterization of adipose tissue macrophages and adipose-derived stem cells in critical wounds

    PubMed Central

    Tilstam, Pathricia V.; Springenberg-Jung, Katrin; Boecker, Arne Hendrick; Schmitz, Corinna; Heinrichs, Daniel; Hwang, Soo Seok; Stromps, Jan Philipp; Ganse, Bergita; Kopp, Ruedger; Knobe, Matthias; Bernhagen, Juergen

    2017-01-01

    Background Subcutaneous adipose tissue is a rich source of adipose tissue macrophages and adipose-derived stem cells which both play a key role in wound repair. While macrophages can be divided into the classically-activated M1 and the alternatively-activated M2 phenotype, ASCs are characterized by the expression of specific stem cell markers. Methods In the present study, we have investigated the expression of common macrophage polarization and stem cell markers in acutely inflamed adipose tissue. Subcutaneous adipose tissue adjacent to acutely inflamed wounds of 20 patients and 20 healthy subjects were harvested and underwent qPCR and flow cytometry analysis. Results Expression levels of the M1-specific markers CD80, iNOS, and IL-1b were significantly elevated in inflammatory adipose tissue when compared to healthy adipose tissue, whereas the M2-specific markers CD163 and TGF-β were decreased. By flow cytometry, a significant shift of adipose tissue macrophage populations towards the M1 phenotype was confirmed. Furthermore, a decrease in the mesenchymal stem cell markers CD29, CD34, and CD105 was observed whereas CD73 and CD90 remained unchanged. Discussion This is the first report describing the predominance of M1 adipose tissue macrophages and the reduction of stem cell marker expression in acutely inflamed, non-healing wounds. PMID:28070458

  14. Caveolae, lipid droplets, and adipose tissue biology: pathophysiological aspects.

    PubMed

    Martin, Sally

    2013-09-01

    Adipocytes are specialized cells that function to store energy in the form of lipids, predominantly triglycerides (TGs), and as a regulatory system contributing to metabolic homoeostasis through the production and secretion of hormones and cytokines. The regulation of lipid homeostasis by adipose tissue is an important aspect of whole-body metabolism. Owing to the central nature of adipose tissue in lipid metabolism, dysregulation has wide-ranging effects, contributing to disorders as diverse as diabetes, cardiovascular disease, cancer, and neurodegeneration. Excess lipids are stored in specialized organelles called lipid droplets (LDs). The surface of the lipid droplet can be considered a highly regulated membrane domain that both protects the contents of the LD from unregulated lipolysis and the cell from the cytotoxic effects of elevated free fatty acids. The surface of the LD is coated with a variety of regulatory proteins, either resident or transiently associated, including enzymes involved in the breakdown of TG, lipid transport proteins, and cofactors. Recent studies have begun to unravel the range of LD-associated proteins and to define their functional significance. Importantly, the involvement of LD proteins in pathophysiological disorders is beginning to be understood. This review will outline recent advances in defining the diversity of LD-associated proteins and their links to metabolic disorders including the integral membrane protein, caveolin-1 (CAV1). Analysis of the role of CAV1 in adipose tissue has highlighted the interconnectedness between the regulation of lipid storage and the function of the adipocyte plasma membrane.

  15. Platelet-Rich Plasma Increases Growth and Motility of Adipose Tissue-Derived Mesenchymal Stem Cells and Controls Adipocyte Secretory Function.

    PubMed

    D'Esposito, Vittoria; Passaretti, Federica; Perruolo, Giuseppe; Ambrosio, Maria Rosaria; Valentino, Rossella; Oriente, Francesco; Raciti, Gregory A; Nigro, Cecilia; Miele, Claudia; Sammartino, Gilberto; Beguinot, Francesco; Formisano, Pietro

    2015-10-01

    Adipose tissue-derived mesenchymal stem cells (Ad-MSC) and platelet derivatives have been used alone or in combination to achieve regeneration of injured tissues. We have tested the effect of platelet-rich plasma (PRP) on Ad-MSC and adipocyte function. PRP increased Ad-MSC viability, proliferation rate and G1-S cell cycle progression, by at least 7-, 2-, and 2.2-fold, respectively, and reduced caspase 3 cleavage. Higher PRP concentrations or PRPs derived from individuals with higher platelet counts were more effective in increasing Ad-MSC growth. PRP also accelerated cell migration by at least 1.5-fold. However, PRP did not significantly affect mature adipocyte viability, differentiation and expression levels of PPAR-γ and AP-2 mRNAs, while it increased leptin production by 3.5-fold. Interestingly, PRP treatment of mature adipocytes also enhanced the release of Interleukin (IL)-6, IL-8, IL-10, Interferon-γ, and Vascular Endothelial Growth Factor. Thus, data are consistent with a stimulatory effect of platelet derivatives on Ad-MSC growth and motility. Moreover, PRP did not reduce mature adipocyte survival and increased the release of pro-angiogenic factors, which may facilitate tissue regeneration processes.

  16. Mechanobiology and Mechanotherapy of Adipose Tissue-Effect of Mechanical Force on Fat Tissue Engineering

    PubMed Central

    Yuan, Yi

    2015-01-01

    Summary: Our bodies are subjected to various mechanical forces, which in turn affect both the structure and function of our bodies. In particular, these mechanical forces play an important role in tissue growth and regeneration. Adipocytes and adipose-derived stem cells are both mechanosensitive and mechanoresponsive. The aim of this review is to summarize the relationship between mechanobiology and adipogenesis. PubMed was used to search for articles using the following keywords: mechanobiology, adipogenesis, adipose-derived stem cells, and cytoskeleton. In vitro and in vivo experiments have shown that adipogenesis is strongly promoted/inhibited by various internal and external mechanical forces, and that these effects are mediated by changes in the cytoskeleton of adipose-derived stem cells and/or various signaling pathways. Thus, adipose tissue engineering could be enhanced by the careful application of mechanical forces. It was shown recently that mature adipose tissue regenerates in an adipose tissue-engineering chamber. This observation has great potential for the reconstruction of soft tissue deficiencies, but the mechanisms behind it remain to be elucidated. On the basis of our understanding of mechanobiology, we hypothesize that the chamber removes mechanical force on the fat that normally impose high cytoskeletal tension. The reduction in tension in adipose stem cells triggers their differentiation into adipocytes. The improvement in our understanding of the relationship between mechanobiology and adipogenesis means that in the near future, we may be able to increase or decrease body fat, as needed in the clinic, by controlling the tension that is loaded onto fat. PMID:26894003

  17. Mechanobiology and Mechanotherapy of Adipose Tissue-Effect of Mechanical Force on Fat Tissue Engineering.

    PubMed

    Yuan, Yi; Gao, Jianhua; Ogawa, Rei

    2015-12-01

    Our bodies are subjected to various mechanical forces, which in turn affect both the structure and function of our bodies. In particular, these mechanical forces play an important role in tissue growth and regeneration. Adipocytes and adipose-derived stem cells are both mechanosensitive and mechanoresponsive. The aim of this review is to summarize the relationship between mechanobiology and adipogenesis. PubMed was used to search for articles using the following keywords: mechanobiology, adipogenesis, adipose-derived stem cells, and cytoskeleton. In vitro and in vivo experiments have shown that adipogenesis is strongly promoted/inhibited by various internal and external mechanical forces, and that these effects are mediated by changes in the cytoskeleton of adipose-derived stem cells and/or various signaling pathways. Thus, adipose tissue engineering could be enhanced by the careful application of mechanical forces. It was shown recently that mature adipose tissue regenerates in an adipose tissue-engineering chamber. This observation has great potential for the reconstruction of soft tissue deficiencies, but the mechanisms behind it remain to be elucidated. On the basis of our understanding of mechanobiology, we hypothesize that the chamber removes mechanical force on the fat that normally impose high cytoskeletal tension. The reduction in tension in adipose stem cells triggers their differentiation into adipocytes. The improvement in our understanding of the relationship between mechanobiology and adipogenesis means that in the near future, we may be able to increase or decrease body fat, as needed in the clinic, by controlling the tension that is loaded onto fat.

  18. Factors involved in white-to-brown adipose tissue conversion and in thermogenesis: a review.

    PubMed

    Montanari, T; Pošćić, N; Colitti, M

    2017-02-10

    Obesity is the result of energy intake chronically exceeding energy expenditure. Classical treatments against obesity do not provide a satisfactory long-term outcome for the majority of patients. After the demonstration of functional brown adipose tissue in human adults, great effort is being devoted to develop therapies based on the adipose tissue itself, through the conversion of fat-accumulating white adipose tissue into energy-dissipating brown adipose tissue. Anti-obesity treatments that exploit endogenous, pharmacological and nutritional factors to drive such conversion are especially in demand. In the present review, we summarize the current knowledge about the various molecules that can be applied in promoting white-to-brown adipose tissue conversion and energy expenditure and the cellular mechanisms involved.

  19. Identification of a Novel Function of Adipocyte Plasma Membrane-Associated Protein (APMAP) in Gestational Diabetes Mellitus by Proteomic Analysis of Omental Adipose Tissue.

    PubMed

    Ma, Yuhang; Gao, Jing; Yin, Jiajing; Gu, Liping; Liu, Xing; Chen, Su; Huang, Qianfang; Lu, Huifang; Yang, Yuemin; Zhou, Hu; Wang, Yufan; Peng, Yongde

    2016-02-05

    Gestational diabetes mellitus (GDM) is considered as an early stage of type 2 diabetes mellitus. In this study, we compared demographic and clinical data between six GDM subjects and six normal glucose tolerance (NGT; healthy controls) subjects and found that homeostasis model of assessment for insulin resistance index (HOMA-IR) increased in GDM. Many previous studies demonstrated that omental adipose tissue dysfunction could induce insulin resistance. Thus, to investigate the cause of insulin resistance in GDM, we used label-free proteomics to identify differentially expressed proteins in omental adipose tissues from GDM and NGT subjects (data are available via ProteomeXchange with identifier PXD003095). A total of 3528 proteins were identified, including 66 significantly changed proteins. Adipocyte plasma membrane-associated protein (APMAP, a.k.a. C20orf3), one of the differentially expressed proteins, was down-regulated in GDM omental adipose tissues. Furthermore, mature 3T3-L1 adipocytes were used to simulate omental adipocytes. The inhibition of APMAP expression by RNAi impaired insulin signaling and activated NFκB signaling in these adipocytes. Our study revealed that the down-regulation of APMAP in omental adipose tissue may play an important role in insulin resistance in the pathophysiology of GDM.

  20. Serially Transplanted Nonpericytic CD146(-) Adipose Stromal/Stem Cells in Silk Bioscaffolds Regenerate Adipose Tissue In Vivo.

    PubMed

    Frazier, Trivia P; Bowles, Annie; Lee, Stephen; Abbott, Rosalyn; Tucker, Hugh A; Kaplan, David; Wang, Mei; Strong, Amy; Brown, Quincy; He, Jibao; Bunnell, Bruce A; Gimble, Jeffrey M

    2016-04-01

    Progenitors derived from the stromal vascular fraction (SVF) of white adipose tissue (WAT) possess the ability to form clonal populations and differentiate along multiple lineage pathways. However, the literature continues to vacillate between defining adipocyte progenitors as "stromal" or "stem" cells. Recent studies have demonstrated that a nonpericytic subpopulation of adipose stromal cells, which possess the phenotype, CD45(-) /CD31(-) /CD146(-) /CD34(+) , are mesenchymal, and suggest this may be an endogenous progenitor subpopulation within adipose tissue. We hypothesized that an adipose progenitor could be sorted based on the expression of CD146, CD34, and/or CD29 and when implanted in vivo these cells can persist, proliferate, and regenerate a functional fat pad over serial transplants. SVF cells and culture expanded adipose stromal/stem cells (ASC) ubiquitously expressing the green fluorescent protein transgene (GFP-Tg) were fractionated by flow cytometry. Both freshly isolated SVF and culture expanded ASC were seeded in three-dimensional silk scaffolds, implanted subcutaneously in wild-type hosts, and serially transplanted. Six-week WAT constructs were removed and evaluated for the presence of GFP-Tg adipocytes and stem cells. Flow cytometry, quantitative polymerase chain reaction, and confocal microscopy demonstrated GFP-Tg cell persistence, proliferation, and expansion, respectively. Glycerol secretion and glucose uptake assays revealed GFP-Tg adipose was metabolically functional. Constructs seeded with GFP-Tg SVF cells or GFP-Tg ASC exhibited higher SVF yields from digested tissue, and higher construct weights, compared to nonseeded controls. Constructs derived from CD146(-) CD34(+) -enriched GFP-Tg ASC populations exhibited higher hemoglobin saturation, and higher frequency of GFP-Tg cells than unsorted or CD29(+) GFP-Tg ASC counterparts. These data demonstrated successful serial transplantation of nonpericytic adipose-derived progenitors that can

  1. Adipose Tissue and Extracellular Matrix Development by Injectable Decellularized Adipose Matrix Loaded with Basic Fibroblast Growth Factor.

    PubMed

    Zhang, Shipin; Lu, Qiqi; Cao, Tong; Toh, Wei Seong

    2016-04-01

    There is a significant need for soft-tissue replacements in the field of reconstructive surgery. Decellularized adipose tissues were heparin crosslinked and loaded with basic fibroblast growth factor (bFGF). This injectable system was evaluated for its adipogenic and angiogenic capabilities for in vivo adipose tissue regeneration. Decellularized adipose tissues were harvested from the inguinal fat pads of C57BL/6J mice, minced, and heparinized before being loaded with bFGF. Decellularized adipose tissues without bFGF served as a control. In vivo adipose neotissue formation, neovascularization, and volume stability were evaluated over a period of 12 weeks. After 6 or 12 weeks, mice were killed and the newly formed adipose tissues, together with the contralateral endogenous adipose tissues, were harvested for gross, volumetric, histologic, and immunohistochemical analysis. Decellularized adipose tissues that were heparinized and loaded with bFGF induced significant de novo adipose neotissue formation, with progressive tissue growth and neovascularization from 6 to 12 weeks. The adipose neotissues exhibited mature adipose morphology and extracellular matrix that closely resembled that of the endogenous adipose tissue. In contrast, decellularized adipose tissues without bFGF induced limited adipose neotissue formation and were completely resorbed by the end of 12 weeks. This study demonstrates the high efficiency of heparinized decellularized adipose tissue matrix loaded with bFGF in promoting adipose neotissue formation and neovascularization with long-term volume stability.

  2. Irbesartan increased PPAR{gamma} activity in vivo in white adipose tissue of atherosclerotic mice and improved adipose tissue dysfunction

    SciTech Connect

    Iwai, Masaru; Kanno, Harumi; Senba, Izumi; Nakaoka, Hirotomo; Moritani, Tomozo; Horiuchi, Masatsugu

    2011-03-04

    Research highlights: {yields} Atherosclerotic apolipoprotein E-deficient (ApoEKO) mice were treated with irbesartan. {yields} Irbesartan decreased white adipose tissue weight without affecting body weight. {yields} DNA-binding for PPAR{gamma} was increased in white adipose tissue in vivo by irbesartan. {yields} Irbesartan increased adipocyte number in white adipose tissue. {yields} Irbesatan increased the expression of adiponectin and leptin in white adipose tissue. -- Abstract: The effect of the PPAR{gamma} agonistic action of an AT{sub 1} receptor blocker, irbesartan, on adipose tissue dysfunction was explored using atherosclerotic model mice. Adult male apolipoprotein E-deficient (ApoEKO) mice at 9 weeks of age were treated with a high-cholesterol diet (HCD) with or without irbesartan at a dose of 50 mg/kg/day for 4 weeks. The weight of epididymal and retroperitoneal adipose tissue was decreased by irbesartan without changing food intake or body weight. Treatment with irbesartan increased the expression of PPAR{gamma} in white adipose tissue and the DNA-binding activity of PPAR{gamma} in nuclear extract prepared from adipose tissue. The expression of adiponectin, leptin and insulin receptor was also increased by irbesartan. These results suggest that irbesartan induced activation of PPAR{gamma} and improved adipose tissue dysfunction including insulin resistance.

  3. Leptin intake in suckling rats restores altered T3 levels and markers of adipose tissue sympathetic drive and function caused by gestational calorie restriction.

    PubMed

    Konieczna, J; Palou, M; Sánchez, J; Picó, C; Palou, A

    2015-06-01

    Maternal calorie restriction during gestation in rats has been associated with altered white adipose tissue (WAT) sympathetic innervation and function in offspring. Here, we aimed to investigate whether supplementation with oral leptin (a breast milk component) throughout the lactation period may revert the aforementioned adverse programming effects. Three groups of male and female rats were studied at the postnatal day 25: the offspring of control dams, the offspring of 20% calorie-restricted dams during pregnancy (CR) and CR rats supplemented with physiological doses of leptin throughout lactation (CR-Leptin). Tyrosine hydroxylase (TH) levels and its immunoreactive area, and mRNA expression levels of lipid metabolism-related genes and of deiodinase iodothyronine type II (Dio2) were determined in WAT. Triiodothyronine (T3) levels were determined in the blood. In CR males, leptin treatment restored the decreased TH levels and its immunoreactive area in WAT, and partially normalized expression levels of genes related to lipolysis and fatty acid oxidation (adipose triglyceride lipase, hormone-sensitive lipase, carnitine palmitoyltransferase 1b and peroxisome proliferator-activated receptor gamma coactivator 1-alpha). Leptin treatment also reverted the decreased T3 plasma levels and WAT lipoprotein lipase mRNA levels occurring in CR males and females, and the decreased Dio2 mRNA levels in CR females. Leptin supplementation throughout the lactation period reverts the malprogrammed effects on WAT structure and function induced by undernutrition during pregnancy. These findings support the relevance of the intake of leptin during lactation, bearing clear characteristics of essential nutrient, and provide a strategy to treat and/or prevent the programmed trend to obesity acquired by inadequate fetal nutrition.

  4. Sex differences in the role of phospholipase A2 -dependent arachidonic acid pathway in the perivascular adipose tissue function in pigs.

    PubMed

    Ahmad, Abdulla A; Randall, Michael D; Roberts, Richard E

    2017-09-06

    The fat surrounding blood vessels (perivascular adipose tissue or PVAT) releases vasoactive compounds that regulate vascular smooth muscle tone. There are sex differences in the regulation of vascular tone, but, to date, no study has investigated whether there are sex differences in the regulation of blood vessel tone by PVAT. This study has identified that the cyclooxygenase products thromboxane and PGF2α are released from coronary artery PVAT from pigs. Thromboxane appears to mediate the PVAT-induced contraction in arteries from females, whereas PGF2α appears to mediate the contraction in arteries from males. These sex differences in the role of these prostanoids in the PVAT-induced contraction can be explained by a greater release of thromboxane from PVAT from female animals and greater sensitivity to PGF2α in the porcine coronary artery from males. Previous studies have demonstrated that perivascular adipose tissue (PVAT) causes vasoconstriction. In this present study, we determined the role of cyclooxygenase-derived prostanoids in this contractile response and determined whether there were any sex differences in the regulation of vascular tone by PVAT. Contractions in isolated segments of coronary arteries were determined using isolated tissue baths and isometric tension recording. Segments were initially cleaned of PVAT, which was then re-added to the tissue bath and changes in tone measured over 1 h. Levels of PGF2α and thromboxane B2 (TXB2 ) were quantified by ELISA, and PGF2α (FP) and thromboxane A2 (TP) receptor expression determined by Western blotting. In arteries from both male and female pigs, re-addition of PVAT caused a contraction, which was partially inhibited by the cyclooxygenase inhibitors indomethacin and flurbiprofen. The FP receptor antagonist AL8810 attenuated the PVAT-induced contraction in arteries from males, whereas the TP receptor antagonist GR32191B inhibited the PVAT-induced contraction in arteries from females. Although there

  5. Adipose-derived stem cells for periodontal tissue regeneration.

    PubMed

    Tobita, Morikuni; Mizuno, Hiroshi

    2011-01-01

    Mesenchymal stem cells can effectively regenerate destroyed periodontal tissue. Because periodontal tissues are complex, mesenchymal stem cells that can differentiate into many tissue types would aid periodontal tissue regeneration. Indeed, periodontal tissue regeneration using mesenchymal stem cells derived from adipose tissue or bone marrow has been performed in experimental animal models, such as rat, canine, swine, and monkey. We have shown that rat periodontal tissue can be regenerated with adipose-derived stem cells. Adipose tissue contains a large number of stromal cells and is relatively easy to obtain in large quantities, and thus constitutes a very convenient stromal cell source. In this chapter, we introduce a rat periodontal tissue regeneration model using adipose-derived stem cells.

  6. The role of adipose tissue in mediating the beneficial effects of dietary fish oil

    PubMed Central

    Puglisi, Michael J.; Hasty, Alyssa H.; Saraswathi, Viswanathan

    2010-01-01

    Fish oil improves several features of metabolic syndrome such as dyslipidemia, insulin resistance and hepatic steatosis. Fish oil may mediate some of its beneficial effects by modulating the storage and/or secretory functions of adipose tissue. The storage of triglycerides in adipose tissue is regulated by the availability of free fatty acids as well as the degree of lipolysis in adipose tissue. Fish oil has been shown to reduce lipolysis in several studies indicating improved triglyceride storage. Importantly, adipose tissue secretes a variety of adipokines and fish oil feeding is associated with remarkable changes in the plasma levels of two key adipokines, adiponectin and leptin. Much attention has been focused on the contribution of adiponectin in fish oil mediated improvements in metabolic syndrome. However, emerging evidence also indicates a role of leptin in modulating the components of the metabolic syndrome upon fish oil feeding. In addition to improving the storage and secretory functions of adipose tissue, fish oil, and the n-3 fatty acids found in fish oil, has been shown to reduce inflammation in adipose tissue. These effects may be in part a result of activation of peroxisome proliferator-activated receptor γ or inhibition of toll-like receptor 4. Thus, there is compelling evidence that fish oil mediates its beneficial effects on metabolic syndrome by improving adipose tissue storage and secretory functions and by reducing inflammation. PMID:21145721

  7. Cell supermarket: Adipose tissue as a source of stem cells

    USDA-ARS?s Scientific Manuscript database

    Adipose tissue is derived from numerous sources, and in recent years has been shown to provide numerous cells from what seemingly was a population of homogeneous adipocytes. Considering the types of cells that adipose tissue-derived cells may form, these cells may be useful in a variety of clinical ...

  8. Altered autophagy in human adipose tissues in obesity

    USDA-ARS?s Scientific Manuscript database

    Context: Autophagy is a housekeeping mechanism, involved in metabolic regulation and stress response, shown recently to regulate lipid droplets biogenesis/breakdown and adipose tissue phenotype. Objective: We hypothesized that in human obesity autophagy may be altered in adipose tissue in a fat d...

  9. Albumin induced cytokine expression in porcine adipose tissue explants

    USDA-ARS?s Scientific Manuscript database

    Albumin has historically been included in medium designed for use with adipose tissue when evaluating metabolism, gene expression or protein secretion. However, recent studies with mouse adipocytes (Ruan et al., J. Biol. Chem. 278:47585-47593, 2003) and human adipose tissue (Schlesinger et al., Ame...

  10. Adipose tissue and the reproductive axis: biological aspects

    USDA-ARS?s Scientific Manuscript database

    The discovery of leptin clearly demonstrated a relationship between body fat and the neuroendocrine axis since leptin influences appetite and the reproductive axis. Since adipose tissue is a primary source of leptin, adipose tissue is no longer considered as simply a depot to store fat. Recent find...

  11. An alternative splicing program promotes adipose tissue thermogenesis

    PubMed Central

    Vernia, Santiago; Edwards, Yvonne JK; Han, Myoung Sook; Cavanagh-Kyros, Julie; Barrett, Tamera; Kim, Jason K; Davis, Roger J

    2016-01-01

    Alternative pre-mRNA splicing expands the complexity of the transcriptome and controls isoform-specific gene expression. Whether alternative splicing contributes to metabolic regulation is largely unknown. Here we investigated the contribution of alternative splicing to the development of diet-induced obesity. We found that obesity-induced changes in adipocyte gene expression include alternative pre-mRNA splicing. Bioinformatics analysis associated part of this alternative splicing program with sequence specific NOVA splicing factors. This conclusion was confirmed by studies of mice with NOVA deficiency in adipocytes. Phenotypic analysis of the NOVA-deficient mice demonstrated increased adipose tissue thermogenesis and improved glycemia. We show that NOVA proteins mediate a splicing program that suppresses adipose tissue thermogenesis. Together, these data provide quantitative analysis of gene expression at exon-level resolution in obesity and identify a novel mechanism that contributes to the regulation of adipose tissue function and the maintenance of normal glycemia. DOI: http://dx.doi.org/10.7554/eLife.17672.001 PMID:27635635

  12. Characterization of peripheral circadian clocks in adipose tissues.

    PubMed

    Zvonic, Sanjin; Ptitsyn, Andrey A; Conrad, Steven A; Scott, L Keith; Floyd, Z Elizabeth; Kilroy, Gail; Wu, Xiying; Goh, Brian C; Mynatt, Randall L; Gimble, Jeffrey M

    2006-04-01

    First described in the suprachiasmatic nucleus, circadian clocks have since been found in several peripheral tissues. Although obesity has been associated with dysregulated circadian expression profiles of leptin, adiponectin, and other fat-derived cytokines, there have been no comprehensive analyses of the circadian clock machinery in adipose depots. In this study, we show robust and coordinated expression of circadian oscillator genes (Npas2, Bmal1, Per1-3, and Cry1-2) and clock-controlled downstream genes (Rev-erb alpha, Rev-erb beta, Dbp, E4bp4, Stra13, and Id2) in murine brown, inguinal, and epididymal (BAT, iWAT, and eWAT) adipose tissues. These results correlated with respective gene expression in liver and the serum markers of circadian function. Through Affymetrix microarray analysis, we identified 650 genes that shared circadian expression profiles in BAT, iWAT, and liver. Furthermore, we have demonstrated that temporally restricted feeding causes a coordinated phase-shift in circadian expression of the major oscillator genes and their downstream targets in adipose tissues. The presence of circadian oscillator genes in fat has significant metabolic implications, and their characterization may have potential therapeutic relevance with respect to the pathogenesis and treatment of diseases such as obesity, type 2 diabetes, and the metabolic syndrome.

  13. The Pathogenesis of Obesity-Associated Adipose Tissue Inflammation.

    PubMed

    Engin, Atilla

    2017-01-01

    Obesity is characterized by a state of chronic, low-grade inflammation. However, excessive fatty acid release may worsen adipose tissue inflammation and contributes to insulin resistance. In this case, several novel and highly active molecules are released abundantly by adipocytes like leptin, resistin, adiponectin or visfatin, as well as some more classical cytokines. Most likely cytokines that are released by inflammatory cells infiltrating obese adipose tissue are such as tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6), monocyte chemoattractant protein 1 (MCP-1) (CCL-2) and IL-1. All of those molecules may act on immune cells leading to local and generalized inflammation. In this process, toll-like receptor 4 (TLR4)/phosphatidylinositol-3'-kinase (PI3K)/Protein kinase B (Akt) signaling pathway, the unfolded protein response (UPR) due to endoplasmic reticulum (ER) stress through hyperactivation of c-Jun N-terminal Kinase (JNK) -Activator Protein 1 (AP1) and inhibitor of nuclear factor kappa-B kinase beta (IKKbeta)-nuclear factor kappa B (NF-kappaB) pathways play an important role, and may also affect vascular endothelial function by modulating vascular nitric oxide and superoxide release. Additionally, systemic oxidative stress, macrophage recruitment, increase in the expression of NOD-like receptor (NLR) family protein (NLRP3) inflammasone and adipocyte death are predominant determinants in the pathogenesis of obesity-associated adipose tissue inflammation. In this chapter potential involvement of these factors that contribute to the adverse effects of obesity are reviewed.

  14. Adipose Tissue Dendritic Cells Are Independent Contributors to Obesity-Induced Inflammation and Insulin Resistance.

    PubMed

    Cho, Kae Won; Zamarron, Brian F; Muir, Lindsey A; Singer, Kanakadurga; Porsche, Cara E; DelProposto, Jennifer B; Geletka, Lynn; Meyer, Kevin A; O'Rourke, Robert W; Lumeng, Carey N

    2016-11-01

    Dynamic changes of adipose tissue leukocytes, including adipose tissue macrophage (ATM) and adipose tissue dendritic cells (ATDCs), contribute to obesity-induced inflammation and metabolic disease. However, clear discrimination between ATDC and ATM in adipose tissue has limited progress in the field of immunometabolism. In this study, we use CD64 to distinguish ATM and ATDC, and investigated the temporal and functional changes in these myeloid populations during obesity. Flow cytometry and immunostaining demonstrated that the definition of ATM as F4/80(+)CD11b(+) cells overlaps with other leukocytes and that CD45(+)CD64(+) is specific for ATM. The expression of core dendritic cell genes was enriched in CD11c(+)CD64(-) cells (ATDC), whereas core macrophage genes were enriched in CD45(+)CD64(+) cells (ATM). CD11c(+)CD64(-) ATDCs expressed MHC class II and costimulatory receptors, and had similar capacity to stimulate CD4(+) T cell proliferation as ATMs. ATDCs were predominantly CD11b(+) conventional dendritic cells and made up the bulk of CD11c(+) cells in adipose tissue with moderate high-fat diet exposure. Mixed chimeric experiments with Ccr2(-/-) mice demonstrated that high-fat diet-induced ATM accumulation from monocytes was dependent on CCR2, whereas ATDC accumulation was less CCR2 dependent. ATDC accumulation during obesity was attenuated in Ccr7(-/-) mice and was associated with decreased adipose tissue inflammation and insulin resistance. CD45(+)CD64(+) ATM and CD45(+)CD64(-)CD11c(+) ATDCs were identified in human obese adipose tissue and ATDCs were increased in s.c. adipose tissue compared with omental adipose tissue. These results support a revised strategy for unambiguous delineation of ATM and ATDC, and suggest that ATDCs are independent contributors to adipose tissue inflammation during obesity. Copyright © 2016 by The American Association of Immunologists, Inc.

  15. Injections of adipose tissue-derived stem cells and stem cell lysate improve recovery of erectile function in a rat model of cavernous nerve injury

    PubMed Central

    Albersen, Maarten; Fandel, Thomas M.; Lin, Guiting; Wang, Guifang; Banie, Lia; Lin, Ching-Shwun; Lue, Tom F.

    2013-01-01

    Introduction Erectile dysfunction (ED) remains a major complication after radical prostatectomy. The use of adipose tissue-derived stem cells (ADSC) has shown promising results for the treatment of ED. However, the mechanisms of action for stem cell therapy remain controversial, with increasing evidence pointing to paracrine pathways. Aim To determine the effects and to identify the mechanism of action of ADSC and ADSC-derived lysate in a rat model of cavernous nerve (CN) crush injury. Methods Thirty-two male Sprague-Dawley rats were randomly divided into four equal groups: one group underwent sham operation, while three groups underwent bilateral CN crush. Crush-injury groups were treated at the time of injury with intracavernous injection of ADSC, lysate, or vehicle only (injured controls). Erectile function was assessed by cavernous nerve electrostimulation at 4 weeks. Penile tissue was collected for histology. Main Outcome Measures Intracavernous pressure increase upon CN stimulation; neuronal nitric oxide synthase (nNOS) content in the dorsal penile nerve; smooth muscle content, collagen content, and number of apoptotic cells in the corpus cavernosum. Results Both ADSC and lysate treatments resulted in significant recovery of erectile function, as compared to vehicle treatment. nNOS content was preserved in both the ADSC and lysate group, with significantly higher expression compared to vehicle-treated animals. There was significantly less fibrosis and a significant preservation of smooth muscle content in the ADSC and lysate groups compared to injured controls. The observed functional improvement after lysate injection supports the hypothesis that ADSC act through release of intracellular preformed substances or by active secretion of certain biomolecules. The underlying mechanism of recovery appears to involve neuron preservation and cytoprotection by inhibition of apoptosis. Conclusions Penile injection of both ADSC and ADSC-derived lysate can improve

  16. The Ontogeny of Brown Adipose Tissue.

    PubMed

    Symonds, Michael E; Pope, Mark; Budge, Helen

    2015-01-01

    There are three different types of adipose tissue (AT)-brown, white, and beige-that differ with stage of development, species, and anatomical location. Of these, brown AT (BAT) is the least abundant but has the greatest potential impact on energy balance. BAT is capable of rapidly producing large amounts of heat through activation of the unique uncoupling protein 1 (UCP1) located within the inner mitochondrial membrane. White AT is an endocrine organ and site of lipid storage, whereas beige AT is primarily white but contains some cells that possess UCP1. BAT first appears in the fetus around mid-gestation and is then gradually lost through childhood, adolescence, and adulthood. We focus on the interrelationships between adipocyte classification, anatomical location, and impact of diet in early life together with the extent to which fat development differs between the major species examined. Ultimately, novel dietary interventions designed to reactivate BAT could be possible.

  17. FEEDING INFLUENCES ADIPOSE TISSUE RESPONSES TO EXERCISE IN OVERWEIGHT MEN.

    PubMed

    Chen, Yung-Chih; Travers, Rebecca L; Walhin, Jean-Philippe; Gonzalez, Javier T; Koumanov, Francoise; Betts, James A; Thompson, Dylan

    2017-03-14

    Feeding profoundly affects metabolic responses to exercise in various tissues but the effect of feeding status on human adipose tissue responses to exercise has never been studied. Ten healthy overweight men aged 26 ± 5 years (mean ± SD) with a waist circumference of 105 ± 10 cm walked at 60% of maximum oxygen uptake under either FASTED or FED conditions in a randomised, counterbalanced design. Feeding comprised 648 ± 115 kcal 2 h before exercise. Blood samples were collected at regular intervals to examine changes in metabolic parameters and adipokine concentrations. Adipose tissue samples were obtained at baseline and one hour post-exercise to examine changes in adipose tissue mRNA expression and secretion of selected adipokines ex-vivo. Adipose tissue mRNA expression of PDK4, ATGL, HSL, FAT/CD36, GLUT4 and IRS2 in response to exercise were lower in FED compared to FASTED conditions (all p ≤ 0.05). Post-exercise adipose IRS2 protein was affected by feeding (p ≤ 0.05), but Akt2, AMPK, IRS1, GLUT4, PDK4 and HSL protein levels were not different. Feeding status did not impact serum and ex-vivo adipose secretion of IL-6, leptin or adiponectin in response to exercise. This is the first study to show that feeding prior to acute exercise affects post-exercise adipose tissue gene expression and we propose that feeding is likely to blunt long-term adipose tissue adaptation to regular exercise.

  18. Porous decellularized adipose tissue foams for soft tissue regeneration.

    PubMed

    Yu, Claire; Bianco, Juares; Brown, Cody; Fuetterer, Lydia; Watkins, John F; Samani, Abbas; Flynn, Lauren E

    2013-04-01

    To design tissue-specific bioscaffolds with well-defined properties and 3-D architecture, methods were developed for preparing porous foams from enzyme-solubilized human decellularized adipose tissue (DAT). Additionally, a technique was established for fabricating "bead foams" comprised of interconnected networks of porous DAT beads fused through a controlled freeze-thawing and lyophilization procedure. In characterization studies, the foams were stable without the need for chemical crosslinking, with properties that could be tuned by controlling the protein concentration and freezing rate during synthesis. Adipogenic differentiation studies with human adipose-derived stem cells (ASCs) suggested that stiffness influenced ASC adipogenesis on the foams. In support of our previous work with DAT scaffolds and microcarriers, the DAT foams and bead foams strongly supported adipogenesis and were also adipo-inductive, as demonstrated by glycerol-3-phosphate dehydrogenase (GPDH) enzyme activity, endpoint RT-PCR analysis of adipogenic gene expression, and intracellular lipid accumulation. Adipogenic differentiation was enhanced on the microporous DAT foams, potentially due to increased cell-cell interactions in this group. In vivo assessment in a subcutaneous Wistar rat model demonstrated that the DAT bioscaffolds were well tolerated and integrated into the host tissues, supporting angiogenesis and adipogenesis. The DAT-based foams induced a strong angiogenic response, promoted inflammatory cell migration and gradually resorbed over the course of 12 weeks, demonstrating potential as scaffolds for wound healing and soft tissue regeneration.

  19. Triglyceride Synthesis in Epididymal Adipose Tissue

    PubMed Central

    Bederman, Ilya R.; Foy, Steven; Chandramouli, Visvanathan; Alexander, James C.; Previs, Stephen F.

    2009-01-01

    The obesity epidemic has generated interest in determining the contribution of various pathways to triglyceride synthesis, including an elucidation of the origin of triglyceride fatty acids and triglyceride glycerol. We hypothesized that a dietary intervention would demonstrate the importance of using glucose versus non-glucose carbon sources to synthesize triglycerides in white adipose tissue. C57BL/6J mice were fed either a low fat, high carbohydrate (HC) diet or a high fat, carbohydrate-free (CF) diet and maintained on 2H2O (to determine total triglyceride dynamics) or infused with [6,6-2H]glucose (to quantify the contribution of glucose to triglyceride glycerol). The 2H2O labeling data demonstrate that although de novo lipogenesis contributed ∼80% versus ∼5% to the pool of triglyceride palmitate in HC- versus CF-fed mice, the epididymal adipose tissue synthesized ∼1.5-fold more triglyceride in CF- versus HC-fed mice, i.e. 37 ± 5 versus 25 ± 3 μmol × day–1. The [6,6-2H]glucose labeling data demonstrate that ∼69 and ∼28% of triglyceride glycerol is synthesized from glucose in HC- versus CF-fed mice, respectively. Although these data are consistent with the notion that non-glucose carbon sources (e.g. glyceroneogenesis) can make substantial contributions to the synthesis of triglyceride glycerol (i.e. the absolute synthesis of triglyceride glycerol from non-glucose substrates increased from ∼8 to ∼26 μmol × day–1 in HC- versus CF-fed mice), these observations suggest (i) the importance of nutritional status in affecting flux rates and (ii) the operation of a glycerol-glucose cycle. PMID:19114707

  20. Global gene expression profiling of brown to white adipose tissue transformation in sheep reveals novel transcriptional components linked to adipose remodeling.

    PubMed

    Basse, Astrid L; Dixen, Karen; Yadav, Rachita; Tygesen, Malin P; Qvortrup, Klaus; Kristiansen, Karsten; Quistorff, Bjørn; Gupta, Ramneek; Wang, Jun; Hansen, Jacob B

    2015-03-19

    Large mammals are capable of thermoregulation shortly after birth due to the presence of brown adipose tissue (BAT). The majority of BAT disappears after birth and is replaced by white adipose tissue (WAT). We analyzed the postnatal transformation of adipose in sheep with a time course study of the perirenal adipose depot. We observed changes in tissue morphology, gene expression and metabolism within the first two weeks of postnatal life consistent with the expected transition from BAT to WAT. The transformation was characterized by massively decreased mitochondrial abundance and down-regulation of gene expression related to mitochondrial function and oxidative phosphorylation. Global gene expression profiling demonstrated that the time points grouped into three phases: a brown adipose phase, a transition phase and a white adipose phase. Between the brown adipose and the transition phase 170 genes were differentially expressed, and 717 genes were differentially expressed between the transition and the white adipose phase. Thirty-eight genes were shared among the two sets of differentially expressed genes. We identified a number of regulated transcription factors, including NR1H3, MYC, KLF4, ESR1, RELA and BCL6, which were linked to the overall changes in gene expression during the adipose tissue remodeling. Finally, the perirenal adipose tissue expressed both brown and brite/beige adipocyte marker genes at birth, the expression of which changed substantially over time. Using global gene expression profiling of the postnatal BAT to WAT transformation in sheep, we provide novel insight into adipose tissue plasticity in a large mammal, including identification of novel transcriptional components linked to adipose tissue remodeling. Moreover, our data set provides a useful resource for further studies in adipose tissue plasticity.

  1. Involvement of lysosomal dysfunction in autophagosome accumulation and early pathologies in adipose tissue of obese mice

    PubMed Central

    Mizunoe, Yuhei; Sudo, Yuka; Okita, Naoyuki; Hiraoka, Hidenori; Mikami, Kentaro; Narahara, Tomohiro; Negishi, Arisa; Yoshida, Miki; Higashibata, Rikako; Watanabe, Shukoh; Kaneko, Hiroki; Natori, Daiki; Furuichi, Takuma; Yasukawa, Hiromine; Kobayashi, Masaki; Higami, Yoshikazu

    2017-01-01

    ABSTRACT Whether obesity accelerates or suppresses autophagy in adipose tissue is still debatable. To clarify dysregulation of autophagy and its role in pathologies of obese adipose tissue, we focused on lysosomal function, protease maturation and activity, both in vivo and in vitro. First, we showed that autophagosome formation was accelerated, but autophagic clearance was impaired in obese adipose tissue. We also found protein and activity levels of CTSL (cathepsin L) were suppressed in obese adipose tissue, while the activity of CTSB (cathepsin B) was significantly enhanced. Moreover, cellular senescence and inflammasomes were activated in obese adipose tissue. In 3T3L1 adipocytes, downregulation of CTSL deteriorated autophagic clearance, upregulated expression of CTSB, promoted cellular senescence and activated inflammasomes. Upregulation of CTSB promoted additional activation of inflammasomes. Therefore, we suggest lysosomal dysfunction observed in obese adipose tissue leads to lower autophagic clearance, resulting in autophagosome accumulation. Simultaneously, lysosomal abnormalities, including deteriorated CTSL function and compensatory activation of CTSB, caused cellular senescence and inflammasome activation. Our findings strongly suggest lysosomal dysfunction is involved in early pathologies of obese adipose tissue. PMID:28121218

  2. Obesity and prostate cancer: gene expression signature of human periprostatic adipose tissue.

    PubMed

    Ribeiro, Ricardo; Monteiro, Cátia; Catalán, Victoria; Hu, Pingzhao; Cunha, Virgínia; Rodríguez, Amaia; Gómez-Ambrosi, Javier; Fraga, Avelino; Príncipe, Paulo; Lobato, Carlos; Lobo, Francisco; Morais, António; Silva, Vitor; Sanches-Magalhães, José; Oliveira, Jorge; Pina, Francisco; Lopes, Carlos; Medeiros, Rui; Frühbeck, Gema

    2012-09-25

    Periprostatic (PP) adipose tissue surrounds the prostate, an organ with a high predisposition to become malignant. Frequently, growing prostatic tumor cells extend beyond the prostatic organ towards this fat depot. This study aimed to determine the genome-wide expression of genes in PP adipose tissue in obesity/overweight (OB/OW) and prostate cancer patients. Differentially expressed genes in human PP adipose tissue were identified using microarrays. Analyses were conducted according to the donors' body mass index characteristics (OB/OW versus lean) and prostate disease (extra prostatic cancer versus organ confined prostate cancer versus benign prostatic hyperplasia). Selected genes with altered expression were validated by real-time PCR. Ingenuity Pathway Analysis (IPA) was used to investigate gene ontology, canonical pathways and functional networks. In the PP adipose tissue of OB/OW subjects, we found altered expression of genes encoding molecules involved in adipogenic/anti-lipolytic, proliferative/anti-apoptotic, and mild immunoinflammatory processes (for example, FADS1, down-regulated, and LEP and ANGPT1, both up-regulated). Conversely, in the PP adipose tissue of subjects with prostate cancer, altered genes were related to adipose tissue cellular activity (increased cell proliferation/differentiation, cell cycle activation and anti-apoptosis), whereas a downward impact on immunity and inflammation was also observed, mostly related to the complement (down-regulation of CFH). Interestingly, we found that the microRNA MIRLET7A2 was overexpressed in the PP adipose tissue of prostate cancer patients. Obesity and excess adiposity modified the expression of PP adipose tissue genes to ultimately foster fat mass growth. In patients with prostate cancer the expression profile of PP adipose tissue accounted for hypercellularity and reduced immunosurveillance. Both findings may be liable to promote a favorable environment for prostate cancer progression.

  3. Obesity and prostate cancer: gene expression signature of human periprostatic adipose tissue

    PubMed Central

    2012-01-01

    Background Periprostatic (PP) adipose tissue surrounds the prostate, an organ with a high predisposition to become malignant. Frequently, growing prostatic tumor cells extend beyond the prostatic organ towards this fat depot. This study aimed to determine the genome-wide expression of genes in PP adipose tissue in obesity/overweight (OB/OW) and prostate cancer patients. Methods Differentially expressed genes in human PP adipose tissue were identified using microarrays. Analyses were conducted according to the donors' body mass index characteristics (OB/OW versus lean) and prostate disease (extra prostatic cancer versus organ confined prostate cancer versus benign prostatic hyperplasia). Selected genes with altered expression were validated by real-time PCR. Ingenuity Pathway Analysis (IPA) was used to investigate gene ontology, canonical pathways and functional networks. Results In the PP adipose tissue of OB/OW subjects, we found altered expression of genes encoding molecules involved in adipogenic/anti-lipolytic, proliferative/anti-apoptotic, and mild immunoinflammatory processes (for example, FADS1, down-regulated, and LEP and ANGPT1, both up-regulated). Conversely, in the PP adipose tissue of subjects with prostate cancer, altered genes were related to adipose tissue cellular activity (increased cell proliferation/differentiation, cell cycle activation and anti-apoptosis), whereas a downward impact on immunity and inflammation was also observed, mostly related to the complement (down-regulation of CFH). Interestingly, we found that the microRNA MIRLET7A2 was overexpressed in the PP adipose tissue of prostate cancer patients. Conclusions Obesity and excess adiposity modified the expression of PP adipose tissue genes to ultimately foster fat mass growth. In patients with prostate cancer the expression profile of PP adipose tissue accounted for hypercellularity and reduced immunosurveillance. Both findings may be liable to promote a favorable environment for

  4. Magnetic Resonance Imaging of Human Tissue-Engineered Adipose Substitutes

    PubMed Central

    Proulx, Maryse; Aubin, Kim; Lagueux, Jean; Audet, Pierre; Auger, Michèle

    2015-01-01

    Adipose tissue (AT) substitutes are being developed to answer the strong demand in reconstructive surgery. To facilitate the validation of their functional performance in vivo, and to avoid resorting to excessive number of animals, it is crucial at this stage to develop biomedical imaging methodologies, enabling the follow-up of reconstructed AT substitutes. Until now, biomedical imaging of AT substitutes has scarcely been reported in the literature. Therefore, the optimal parameters enabling good resolution, appropriate contrast, and graft delineation, as well as blood perfusion validation, must be studied and reported. In this study, human adipose substitutes produced from adipose-derived stem/stromal cells using the self-assembly approach of tissue engineering were implanted into athymic mice. The fate of the reconstructed AT substitutes implanted in vivo was successfully followed by magnetic resonance imaging (MRI), which is the imaging modality of choice for visualizing soft ATs. T1-weighted images allowed clear delineation of the grafts, followed by volume integration. The magnetic resonance (MR) signal of reconstructed AT was studied in vitro by proton nuclear magnetic resonance (1H-NMR). This confirmed the presence of a strong triglyceride peak of short longitudinal proton relaxation time (T1) values (200±53 ms) in reconstructed AT substitutes (total T1=813±76 ms), which establishes a clear signal difference between adjacent muscle, connective tissue, and native fat (total T1 ∼300 ms). Graft volume retention was followed up to 6 weeks after implantation, revealing a gradual resorption rate averaging at 44% of initial substitute's volume. In addition, vascular perfusion measured by dynamic contrast-enhanced-MRI confirmed the graft's vascularization postimplantation (14 and 21 days after grafting). Histological analysis of the grafted tissues revealed the persistence of numerous adipocytes without evidence of cysts or tissue necrosis. This study

  5. Sex differences in the effect of high-fat diet feeding on rat white adipose tissue mitochondrial function and insulin sensitivity.

    PubMed

    Amengual-Cladera, Emilia; Lladó, Isabel; Gianotti, Magdalena; Proenza, Ana M

    2012-08-01

    Obesity-induced mitochondrial dysfunction in white adipose tissue (WAT) leads to a dysregulation of adipokine secretion, which is involved in insulin resistance development. Taking into account the sex differences previously found both in mitochondrial function and for the insulin sensitivity profile in different tissues, the aim of this study was to investigate whether a sex-dependent effect of a long-term high-fat diet (HFD) feeding exists on WAT mitochondrial function. Indeed, HFD effects on the levels of the key components of the insulin and adiponectin signaling pathways, and the consequences of these effects on the systemic profile of insulin sensitivity were also studied. Wistar rats of both sexes were fed a standard diet or an HFD. Serum markers of insulin sensitivity, protein, and mRNA levels of the main elements of the insulin and adiponectin signaling pathways, and the markers of mitochondrial function and biogenesis, were measured. Our results indicate that different physiological strategies are adopted by male and female rats in response to HFD. In this regard, HFD induced mitochondrial proliferation in males and mitochondrial differentiation in females, as well as a greater retroperitoneal WAT expandability capacity, which allows them to preserve a better insulin sensitivity profile than male rats for both control and HFD groups. Moreover, female WAT showed a decrease in adiponectin and insulin signaling pathway element levels. This sexual dimorphism suggests that there are different strategies for retroperitoneal WAT to maintain the energetic and metabolic homeostasis in response to HFD feeding. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Epicardial Adipose Tissue Is Nonlinearly Related to Anthropometric Measures and Subcutaneous Adipose Tissue.

    PubMed

    Šram, Miroslav; Vrselja, Zvonimir; Lekšan, Igor; Ćurić, Goran; Selthofer-Relatić, Kristina; Radić, Radivoje

    2015-01-01

    Introduction. Adipose tissue is the largest endocrine organ, composed of subcutaneous (SAT) and visceral adipose tissue (VAT), the latter being highly associated with coronary artery disease (CAD). Expansion of epicardial adipose tissue (EAT) is linked to CAD. One way of assessing the CAD risk is with low-cost anthropometric measures, although they are inaccurate and cannot discriminate between VAT and SAT. The aim of this study is to evaluate (1) the relationship between EAT thickness, SAT thickness and anthropometric measures in a cohort of patients assessed at the cardiology unit and (2) determine predictive power of anthropometric measures and EAT and SAT thickness in establishment of CAD. Methods. Anthropometric measures were obtained from 53 CAD and 42 non-CAD patients. Vascular and structural statuses were obtained with coronarography and echocardiography, as well as measurements of the EAT and SAT thickness. Results. Anthropometric measures showed moderate positive correlation with EAT and SAT thickness. Anthropometric measures and SAT follow nonlinear S curve relationship with EAT. Strong nonlinear power curve relationship was observed between EAT and SAT thinner than 10 mm. Anthropometric measures and EAT and SAT were poor predictors of CAD. Conclusion. Anthropometric measures and SAT have nonlinear relationship with EAT. EAT thickness and anthropometric measures have similar CAD predictive value.

  7. Microarray analysis of differentially expressed genes and their functions in omental visceral adipose tissues of pregnant women with vs. without gestational diabetes mellitus.

    PubMed

    Qian, Yuan; Sun, Hao; Xiao, Hongli; Ma, Meirun; Xiao, Xue; Qu, Qinzai

    2017-05-01

    Increasing evidence has shown that insulin resistance in omental visceral adipose tissue (OVAT) is a characteristic of gestational diabetes mellitus (GDM). The present study aimed to identify differentially expressed genes (DEGs) and their associated functions and pathways involved in the pathogenesis of GDM by comparing the expression profiles of OVATs obtained from pregnant Chinese women with and without GDM during caesarian section. A total of 935 DEGs were identified, including 450 downregulated and 485 upregulated genes. In the gene ontology category cellular components, the DEGs were predominantly associated with functions of the extracellular region, while receptor binding was predominant in the molecular function category and biological process terms included antigen processing and presentation, extracellular matrix organization, positive regulation of cell-substrate adhesion, response to nutrients and response to dietary excess. Functional enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment were performed and a functional interaction network was constructed. Functions of downregulated genes included antigen processing and presentation as well as cell adhesion molecules, while those of upregulated genes included transforming growth factor (TGF)-β-signaling, focal adhesion, phosphoinositide-3 kinase-Akt-signaling, P53 signaling, extracellular matrix-receptor interaction and regulation of actin cytoskeleton pathway. The five main pathways associated with GDM were antigen processing and presentation, cell adhesion molecules, Type 1 diabetes mellitus, natural killer cell-mediated cytotoxicity and TGF-β signaling. These pathways were included in the KEGG pathway categories of 'signaling molecules and interaction', 'immune system' and 'inflammatory response', suggesting that these processes are involved in GDM. The results of the present study enhanced the present understanding of the mechanisms associated with insulin resistance in

  8. Role of adipose tissue in the pathogenesis of cardiac arrhythmias.

    PubMed

    Samanta, Rahul; Pouliopoulos, Jim; Thiagalingam, Aravinda; Kovoor, Pramesh

    2016-01-01

    Epicardial adipose tissue is present in normal healthy individuals. It is a unique fat depot that, under physiologic conditions, plays a cardioprotective role. However, excess epicardial adipose tissue has been shown to be associated with prevalence and severity of atrial fibrillation. In arrhythmogenic right ventricular cardiomyopathy and myotonic dystrophy, fibrofatty infiltration of the myocardium is associated with ventricular arrhythmias. In the ovine model of ischemic cardiomyopathy, the presence of intramyocardial adipose or lipomatous metaplasia has been associated with increased propensity to ventricular tachycardia. These observations suggest a role of adipose tissue in the pathogenesis of cardiac arrhythmias. In this article, we review the role of cardiac adipose tissue in various cardiac arrhythmias and discuss the possible pathophysiologic mechanisms.

  9. Brown adipose tissue and novel therapeutic approaches to treat metabolic disorders.

    PubMed

    Roman, Sabiniano; Agil, Ahmad; Peran, Macarena; Alvaro-Galue, Eduardo; Ruiz-Ojeda, Francisco J; Fernández-Vázquez, Gumersindo; Marchal, Juan A

    2015-04-01

    In humans, 2 functionally different types of adipose tissue coexist: white adipose tissue (WAT) and brown adipose tissue (BAT). WAT is involved in energy storage, whereas BAT is involved in energy expenditure. Increased amounts of WAT may contribute to the development of metabolic disorders, such as obesity-associated type 2 diabetes mellitus and cardiovascular diseases. In contrast, the thermogenic function of BAT allows high consumption of fatty acids because of the activity of uncoupling protein 1 in the internal mitochondrial membrane. Interestingly, obesity reduction and insulin sensitization have been achieved by BAT activation-regeneration in animal models. This review describes the origin, function, and differentiation mechanisms of BAT to identify new therapeutic strategies for the treatment of metabolic disorders related to obesity. On the basis of the animal studies, novel approaches for BAT regeneration combining stem cells from the adipose tissue with active components, such as melatonin, may have potential for the treatment of metabolic disorders in humans.

  10. Berberine activates thermogenesis in white and brown adipose tissue.

    PubMed

    Zhang, Zhiguo; Zhang, Huizhi; Li, Bo; Meng, Xiangjian; Wang, Jiqiu; Zhang, Yifei; Yao, Shuangshuang; Ma, Qinyun; Jin, Lina; Yang, Jian; Wang, Weiqing; Ning, Guang

    2014-11-25

    Obesity develops when energy intake exceeds energy expenditure. Promoting brown adipose tissue formation and function increases energy expenditure and hence may counteract obesity. Berberine (BBR) is a compound derived from the Chinese medicinal plant Coptis chinensis. Here we show that BBR increases energy expenditure, limits weight gain, improves cold tolerance and enhances brown adipose tissue (BAT) activity in obese db/db mice. BBR markedly induces the development of brown-like adipocytes in inguinal, but not epididymal adipose depots. BBR also increases expression of UCP1 and other thermogenic genes in white and BAT and primary adipocytes via a mechanism involving AMPK and PGC-1α. BBR treatment also inhibits AMPK activity in the hypothalamus, but genetic activation of AMPK in the ventromedial nucleus of the hypothalamus does not prevent BBR-induced weight loss and activation of the thermogenic programme. Our findings establish a role for BBR in regulating organismal energy balance, which may have potential therapeutic implications for the treatment of obesity.

  11. Central Nervous System Regulation of Brown Adipose Tissue

    PubMed Central

    Morrison, Shaun F.; Madden, Christopher J.

    2015-01-01

    Thermogenesis, the production of heat energy, in brown adipose tissue is a significant component of the homeostatic repertoire to maintain body temperature during the challenge of low environmental temperature in many species from mouse to man and plays a key role in elevating body temperature during the febrile response to infection. The sympathetic neural outflow determining brown adipose tissue (BAT) thermogenesis is regulated by neural networks in the CNS which increase BAT sympathetic nerve activity in response to cutaneous and deep body thermoreceptor signals. Many behavioral states, including wakefulness, immunologic responses, and stress, are characterized by elevations in core body temperature to which central command-driven BAT activation makes a significant contribution. Since energy consumption during BAT thermogenesis involves oxidation of lipid and glucose fuel molecules, the CNS network driving cold-defensive and behavioral state-related BAT activation is strongly influenced by signals reflecting the short and long-term availability of the fuel molecules essential for BAT metabolism and, in turn, the regulation of BAT thermogenesis in response to metabolic signals can contribute to energy balance, regulation of body adipose stores and glucose utilization. This review summarizes our understanding of the functional organization and neurochemical influences within the CNS networks that modulate the level of BAT sympathetic nerve activity to produce the thermoregulatory and metabolic alterations in BAT thermogenesis and BAT energy expenditure that contribute to overall energy homeostasis and the autonomic support of behavior. PMID:25428857

  12. Evidence of early alterations in adipose tissue biology and function and its association with obesity-related inflammation and insulin resistance in children.

    PubMed

    Landgraf, Kathrin; Rockstroh, Denise; Wagner, Isabel V; Weise, Sebastian; Tauscher, Roy; Schwartze, Julian T; Löffler, Dennis; Bühligen, Ulf; Wojan, Magdalena; Till, Holger; Kratzsch, Jürgen; Kiess, Wieland; Blüher, Matthias; Körner, Antje

    2015-04-01

    Accumulation of fat mass in obesity may result from hypertrophy and/or hyperplasia and is frequently associated with adipose tissue (AT) dysfunction in adults. Here we assessed early alterations in AT biology and function by comprehensive experimental and clinical characterization of 171 AT samples from lean and obese children aged 0 to 18 years. We show an increase in adipocyte size and number in obese compared with lean children beginning in early childhood. These alterations in AT composition in obese children were accompanied by decreased basal lipolytic activity and significantly enhanced stromal vascular cell proliferation in vitro, potentially underlying the hypertrophy and hyperplasia seen in obese children, respectively. Furthermore, macrophage infiltration, including the formation of crown-like structures, was increased in AT of obese children from 6 years on and was associated with higher hs-CRP serum levels. Clinically, adipocyte hypertrophy was not only associated with leptin serum levels but was highly and independently correlated with HOMA-IR as a marker of insulin resistance in children. In summary, we show that adipocyte hypertrophy is linked to increased inflammation in AT in obese children, thereby providing evidence that obesity-associated AT dysfunction develops in early childhood and is related to insulin resistance. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  13. Reproducibility and Repeatability of Computer Tomography-based Measurement of Abdominal Subcutaneous and Visceral Adipose Tissues

    PubMed Central

    Lee, Yuan-Hao; Hsiao, Hsing-Fen; Yang, Hou-Ting; Huang, Shih-Yi; Chan, Wing P.

    2017-01-01

    Excessive accumulation of abdominal adipose tissue is a widely recognized as a major feature of obesity, and it can be quantified by dual-energy x-ray absorptiometry (DXA). However, in a phantom study, the inter- and intra-instrument reliability of DXA remains unpredictable. Thus, we attempted to determine the precision of estimates from computer tomography-based measurements and analysis with AZE Virtual Place software. To determine the inter-rater reproducibility and intra-rater repeatability of adipose tissue area estimates, we used the automatic boundary-tracing function of the AZE Virtual Place to generate cross-sectional areas of subcutaneous and visceral adipose tissues from the abdomen of reconstructed CT images. The variability of inter-rater and intra-rater estimates expressed as the coefficient of variation ranged from 0.47% to 1.43% for subcutaneous adipose tissue and 1.08% to 2.20% for visceral adipose tissue; the optimal coefficient of variation of the fat rate calculation ranged from 0.55% to 1.13%, respectively. There was high and significant correlation between adipose tissue areas as estimated in 40 obese subjects by two raters or repeatedly on 20 obese subjects by either rater. This indicates excellent reproducibility and repeatability via a computer tomography-based measurement of abdominal subcutaneous and visceral adipose tissues. PMID:28071718

  14. Extracellular Vesicles from Adipose Tissue-A Potential Role in Obesity and Type 2 Diabetes?

    PubMed

    Gao, Xuan; Salomon, Carlos; Freeman, Dilys J

    2017-01-01

    Adipose tissue plays a key role in the development of insulin resistance and its pathological sequelae, such as type 2 diabetes and non-alcoholic fatty liver disease. Dysfunction in the adipose tissue response to storing excess fatty acids as triglyceride can lead to adipose tissue inflammation and spillover of fatty acids from this tissue and accumulation of fatty acids as lipid droplets in ectopic sites, such as liver and muscle. Extracellular vesicles (EVs) are released from adipocytes and have been proposed to be involved in adipocyte/macrophage cross talk and to affect insulin signaling and transforming growth factor β expression in liver cells leading to metabolic disease. Furthermore EV produced by adipose tissue-derived mesenchymal stem cells (ADSC) can promote angiogenesis and cancer cell migration and have neuroprotective and neuroregenerative properties. ADSC EVs have therapeutic potential in vascular and neurodegenerative disease and may also be used to target specific functional miRNAs to cells. Obesity is associated with an increase in adipose-derived EV which may be related to the metabolic complications of obesity. In this review, we discuss our current knowledge of EV produced by adipose tissue and the potential impact of adipose tissue-derived EV on metabolic diseases associated with obesity.

  15. A novel ChREBP isoform in adipose tissue regulates systemic glucose metabolism.

    PubMed

    Herman, Mark A; Peroni, Odile D; Villoria, Jorge; Schön, Michael R; Abumrad, Nada A; Blüher, Matthias; Klein, Samuel; Kahn, Barbara B

    2012-04-19

    The prevalence of obesity and type 2 diabetes is increasing worldwide and threatens to shorten lifespan. Impaired insulin action in peripheral tissues is a major pathogenic factor. Insulin stimulates glucose uptake in adipose tissue through the GLUT4 (also known as SLC2A4) glucose transporter, and alterations in adipose tissue GLUT4 expression or function regulate systemic insulin sensitivity. Downregulation of human and mouse adipose tissue GLUT4 occurs early in diabetes development. Here we report that adipose tissue GLUT4 regulates the expression of carbohydrate-responsive-element-binding protein (ChREBP; also known as MLXIPL), a transcriptional regulator of lipogenic and glycolytic genes. Furthermore, adipose ChREBP is a major determinant of adipose tissue fatty acid synthesis and systemic insulin sensitivity. We find a new mechanism for glucose regulation of ChREBP: glucose-mediated activation of the canonical ChREBP isoform (ChREBP-α) induces expression of a novel, potent isoform (ChREBP-β) that is transcribed from an alternative promoter. ChREBP-β expression in human adipose tissue predicts insulin sensitivity, indicating that it may be an effective target for treating diabetes.

  16. Adipose tissue remodeling in lipedema: adipocyte death and concurrent regeneration.

    PubMed

    Suga, Hirotaka; Araki, Jun; Aoi, Noriyuki; Kato, Harunosuke; Higashino, Takuya; Yoshimura, Kotaro

    2009-12-01

    Lipedema is a disease with unknown etiology presenting as bilateral and symmetric enlargement of the lower extremities due to subcutaneous deposition of the adipose tissue. Here we describe the histopathological features of the lipedema tissue and nonaffected adipose tissue obtained from a typical patient with severe lipedema. Immunohistochemical analyses indicated degenerative and regenerative changes of the lipedema tissue, characterized by crown-like structures (necrotizing adipocytes surrounded by infiltrating CD68+ macrophages; a feature commonly seen in obese adipose tissue) and proliferation of adipose-derived stem/progenitor/stromal cells (Ki67+CD34+ cells), respectively. These findings suggested increased adipogenesis in the lipedema tissue, which may further lead to hypoxia similar to that seen in obesity, resulting in adipocyte necrosis and macrophage recruitment. The confinement to the lower extremities and the difference from systemic obesity warrants further elucidation in future studies.

  17. Genetics-based manipulation of adipose tissue sympathetic innervation.

    PubMed

    François, Marie; Qualls-Creekmore, Emily; Berthoud, Hans-Rudolf; Münzberg, Heike; Yu, Sangho

    2017-08-28

    There is renewed interest in leveraging the thermogenic capacity of brown adipose tissue (BAT) and browning of white adipose tissue (WAT) to improve energy balance and prevent obesity. In addition to these effects on energy expenditure, both BAT and WAT secrete large numbers of hormones and cytokines that play important roles in maintaining metabolic health. Both BAT and WAT are densely innervated by the sympathetic nervous system (SNS) and this innervation is crucial for BAT thermogenesis and WAT browning, making it a potentially interesting target for manipulating energy balance and treatment of obesity and metabolic disease. Peripheral neuromodulation in the form of electrical manipulation of the SNS and parasympathetic nervous system (PSNS) has been used for the management of pain and many other conditions, but progress is hampered by lack of detailed knowledge of function-specific neurons and nerves innervating particular organs and tissues. Therefore, the goal of the National Institutes of Health (NIH) Common Fund project "Stimulating Peripheral Activity to Relieve Conditions (SPARC)" is to comprehensively map both anatomical and neurochemical aspects of the peripheral nervous system in animal model systems to ultimately guide optimal neuromodulation strategies in humans. Compared to electrical manipulation, neuron-specific opto- and chemogenetic manipulation, now being extensively used to decode the function of brain circuits, will further increase the functional specificity of peripheral neuromodulation. Copyright © 2017. Published by Elsevier Inc.

  18. Brown adipose tissue as a secretory organ.

    PubMed

    Villarroya, Francesc; Cereijo, Rubén; Villarroya, Joan; Giralt, Marta

    2017-01-01

    Brown adipose tissue (BAT) is the main site of adaptive thermogenesis and experimental studies have associated BAT activity with protection against obesity and metabolic diseases, such as type 2 diabetes mellitus and dyslipidaemia. Active BAT is present in adult humans and its activity is impaired in patients with obesity. The ability of BAT to protect against chronic metabolic disease has traditionally been attributed to its capacity to utilize glucose and lipids for thermogenesis. However, BAT might also have a secretory role, which could contribute to the systemic consequences of BAT activity. Several BAT-derived molecules that act in a paracrine or autocrine manner have been identified. Most of these factors promote hypertrophy and hyperplasia of BAT, vascularization, innervation and blood flow, processes that are all associated with BAT recruitment when thermogenic activity is enhanced. Additionally, BAT can release regulatory molecules that act on other tissues and organs. This secretory capacity of BAT is thought to be involved in the beneficial effects of BAT transplantation in rodents. Fibroblast growth factor 21, IL-6 and neuregulin 4 are among the first BAT-derived endocrine factors to be identified. In this Review, we discuss the current understanding of the regulatory molecules (the so-called brown adipokines or batokines) that are released by BAT that influence systemic metabolism and convey the beneficial metabolic effects of BAT activation. The identification of such adipokines might also direct drug discovery approaches for managing obesity and its associated chronic metabolic diseases.

  19. Adipose tissue and skeletal muscle blood flow during mental stress

    SciTech Connect

    Linde, B.; Hjemdahl, P.; Freyschuss, U.; Juhlin-Dannfelt, A.

    1989-01-01

    Mental stress (a modified Stroop color word conflict test (CWT)) increased adipose tissue blood flow (ATBF; 133Xe clearance) by 70% and reduced adipose tissue vascular resistance (ATR) by 25% in healthy male volunteers. The vasculatures of adipose tissue (abdomen as well as thigh), skeletal muscle of the calf (133Xe clearance), and the entire calf (venous occlusion plethysmography) responded similarly. Arterial epinephrine (Epi) and glycerol levels were approximately doubled by stress. Beta-Blockade by metoprolol (beta 1-selective) or propranolol (nonselective) attenuated CWT-induced tachycardia similarly. Metoprolol attenuated stress-induced vasodilation in the calf and tended to do so in adipose tissue. Propranolol abolished vasodilation in the calf and resulted in vasoconstriction during CWT in adipose tissue. Decreases in ATR, but not in skeletal muscle or calf vascular resistances, were correlated to increases in arterial plasma glycerol (r = -0.42, P less than 0.05), whereas decreases in skeletal muscle and calf vascular resistances, but not in ATR, were correlated to increases in arterial Epi levels (r = -0.69, P less than 0.01; and r = -0.43, P less than 0.05, respectively). The results suggest that mental stress increases nutritive blood flow in adipose tissue and skeletal muscle considerably, both through the elevation of perfusion pressure and via vasodilatation. Withdrawal of vasoconstrictor nerve activity, vascular beta 2-adrenoceptor stimulation by circulating Epi, and metabolic mechanisms (in adipose tissue) may contribute to the vasodilatation.

  20. Adipose tissue macrophages: the inflammatory link between obesity and cancer?

    PubMed

    Wagner, Marek; Samdal Steinskog, Eli Sihn; Wiig, Helge

    2015-04-01

    Obesity has increased dramatically over the last three decades. Thus, epidemiological evidence linking obesity and cancer has ignited our interest in the relationship between adipose tissue mass and cancer development. Obesity is defined as an excess of adipose tissue that is typified by a chronic, low-grade inflammatory response instigated by macrophage infiltration. Therefore, in this review, we will discuss the putative causal relationship between obesity-induced chronic inflammation and cancer with particular focus on adipose tissue macrophages. Chronic, low-grade inflammation has long been associated with cancer initiation, promotion and progression. Therefore, signals derived from adipose tissue macrophages may play a significant role in carcinogenesis. In this review we will discuss the molecular mechanisms of cancer development in obesity and highlight possible therapeutic strategies aiming at adipose tissue macrophages. The strong correlation between tumor-associated macrophage infiltration and tumor growth and progression emphasizes the value of macrophages as an effective therapeutic target. It remains to be deciphered to what extent adipose tissue macrophages contribute to these processes, especially in tumors growing within or adjacent to adipose tissue. More effort should also be placed on elucidating macrophage differences between humans and mice that may lead to the development of more effective diagnostic and therapeutic strategies.

  1. Differential expression of Dlk-1 in bovine adipose tissue depots.

    PubMed

    Vuocolo, T; Pearson, R; Campbell, P; Tellam, R L

    2003-02-01

    Dlk-1, a type 1 membrane glycoprotein, is a member of the Epidermal Growth Factor-like family of homeotic proteins that are typically involved in cell fate decisions and in mice it has been implicated in the control of differentiation of adipocytes. The aim of this study was to determine whether there were tissue-specific expression patterns of Dlk-1 splice variants in bovine tissues. Only the Dlk-1-C2 variant was expressed in adult bovine tissues while both Dlk-1-C2 and Dlk-1-A variants were expressed in foetal tissues. Quantitative real-time PCR revealed large differences in the relative levels of expression of the Dlk-1-C2 variant in adult adipose tissue depots with no expression in subcutaneous and brisket adipose tissues. Expression was also demonstrated in three adult skeletal muscle samples. The large variation in the level of expression of Dlk-1-C2 in different adult tissues may reflect the relative preadipocyte content of those tissues and consequently their potential for generating new adipocytes. A low abundance soluble glycoprotein (bFA1) was purified from bovine amniotic fluid. Analyses of its amino acid sequence revealed that it corresponded to most of the extracellular domain of bovine Dlk-1 and was derived by proteolytic processing from the full-length Dlk-1 protein encoded by the Dlk-1-A variant. The tissues expressing the Dlk-1-A variant have not been identified but are likely to be foetal in origin. Splice variants of Dlk-1 may have varied functional roles with the foetal Dlk-1-A form capable of generating a protein that undergoes proteolytic processing to release a soluble ecto-domain of Dlk-1. In contrast the Dlk-1-C2 splice variant codes for a protein lacking this processing site and therefore it probably remains bound to the cell membrane.

  2. Cell Supermarket: Adipose Tissue as a Source of Stem Cells

    PubMed Central

    Dodson, M.V.; Wei, S.; Duarte, M.; Du, M.; Jiang, Z.; Hausman, G.J.; Bergen, W.G.

    2013-01-01

    Adipose tissue is derived from numerous sources, and in recent years this tissue has been shown to provide numerous cells from what seemingly was a population of homogeneous adipocytes. Considering the types of cells that adipose tissue-derived cells may form, these cells may be useful in a variety of clinical and scientific applications. The focus of this paper is to reflect on this area of research and to provide a list of potential (future) research areas. PMID:25031654

  3. Obesity-induced Changes in Adipose Tissue Microenvironment and Their Impact on Cardiovascular Disease

    PubMed Central

    Fuster, Jose J.; Ouchi, Noriyuki; Gokce, Noyan; Walsh, Kenneth

    2016-01-01

    Obesity is causally linked with the development of cardiovascular disorders. Accumulating evidence indicates that cardiovascular disease is the “collateral damage” of obesity-driven adipose tissue dysfunction that promotes a chronic inflammatory state within the organism. Adipose tissues secrete bioactive substances, referred to as adipokines, which largely function as modulators of inflammation. The microenvironment of adipose tissue will affect the adipokine secretome, having actions on remote tissues. Obesity typically leads to the upregulation of pro-inflammatory adipokines and the downregulation of anti-inflammatory adipokines, thereby contributing to the pathogenesis of cardiovascular diseases. In this review, we focus on the microenvironment of adipose tissue and how it influences cardiovascular disorders, including atherosclerosis and ischemic heart diseases, through the systemic actions of adipokines. PMID:27230642

  4. Dual function of Lactobacillus kefiri DH5 in preventing high-fat-diet-induced obesity: direct reduction of cholesterol and upregulation of PPAR-α in adipose tissue.

    PubMed

    Kim, Dong-Hyeon; Jeong, Dana; Kang, Il-Byeong; Kim, Hyunsook; Song, Kwang-Young; Seo, Kun-Ho

    2017-07-10

    Kefir consumption inhibits the development of obesity and non-alcoholic fatty liver disease (NALFD) in mice fed 60% high-fat diet (HFD). To identify the key contributor of this effect, we isolated lactic acid bacteria (LAB) from kefir and examined their anti-obesity properties from in vitro screening and in vivo validation. Thirteen kefir LAB isolates were subjected to survivability test using artificial gastrointestinal environment and cholesterol-reducing assay. Lactobacillus kefiri DH5 showed 100% survivability in gastrointestinal environments and reduced 51.6% of cholesterol; thus, this strain was selected for in vivo experiment. Compared to the HFD-saline group, the HFD-DH5 group showed significantly lower body weight (34.68 versus 31.10 g; p < 0.001), epididymal adipose tissue weight (1.39 versus 1.05 g; p < 0.001), blood triglyceride (38.2 versus 31.0 mg/dL; p < 0.01) and LDL-cholesterol levels (19.4 versus 15.7 mg/dL; p < 0.01). In addition, L. kefiri DH5 administration significantly modulated gut microbiota of HFD-fed mice. The hepatic steatosis was significantly milder (Lesion score, 2.1 versus 1.2; p < 0.001) and adipocyte diameter was significantly smaller (65.1 versus 42.2 μm; p < 0.001) in the HFD-DH5 group. L. kefiri DH5 upregulated PPAR-α, FABP4, and CPT1 expression in the epididymal adipose tissues (2.29-, 1.77-, and 2.05-fold change, respectively), suggesting a reduction in adiposity by stimulating fatty acid oxidation. L. kefiri DH5 exerts anti-obesity effects by direct reduction of cholesterol in the lumen and upregulation of PPAR-α gene in adipose tissues. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Adipose tissue and adrenal glands: novel pathophysiological mechanisms and clinical applications.

    PubMed

    Kargi, Atil Y; Iacobellis, Gianluca

    2014-01-01

    Hormones produced by the adrenal glands and adipose tissues have important roles in normal physiology and are altered in many disease states. Obesity is associated with changes in adrenal function, including increase in adrenal medullary catecholamine output, alterations of the hypothalamic-pituitary-adrenal (HPA) axis, elevations in circulating aldosterone together with changes in adipose tissue glucocorticoid metabolism, and enhanced adipocyte mineralocorticoid receptor activity. It is unknown whether these changes in adrenal endocrine function are in part responsible for the pathogenesis of obesity and related comorbidities or represent an adaptive response. In turn, adipose tissue hormones or "adipokines" have direct effects on the adrenal glands and interact with adrenal hormones at several levels. Here we review the emerging evidence supporting the existence of "cross talk" between the adrenal gland and adipose tissue, focusing on the relevance and roles of their respective hormones in health and disease states including obesity, metabolic syndrome, and primary disorders of the adrenals.

  6. Loss of Oncostatin M Signaling in Adipocytes Induces Insulin Resistance and Adipose Tissue Inflammation in Vivo.

    PubMed

    Elks, Carrie M; Zhao, Peng; Grant, Ryan W; Hang, Hardy; Bailey, Jennifer L; Burk, David H; McNulty, Margaret A; Mynatt, Randall L; Stephens, Jacqueline M

    2016-08-12

    Oncostatin M (OSM) is a multifunctional gp130 cytokine. Although OSM is produced in adipose tissue, it is not produced by adipocytes. OSM expression is significantly induced in adipose tissue from obese mice and humans. The OSM-specific receptor, OSM receptor β (OSMR), is expressed in adipocytes, but its function remains largely unknown. To better understand the effects of OSM in adipose tissue, we knocked down Osmr expression in adipocytes in vitro using siRNA. In vivo, we generated a mouse line lacking Osmr in adiponectin-expressing cells (OSMR(FKO) mice). The effects of OSM on gene expression were also assessed in vitro and in vivo OSM exerts proinflammatory effects on cultured adipocytes that are partially rescued by Osmr knockdown. Osm expression is significantly increased in adipose tissue T cells of high fat-fed mice. In addition, adipocyte Osmr expression is increased following high fat feeding. OSMR(FKO) mice exhibit increased insulin resistance and adipose tissue inflammation and have increased lean mass, femoral length, and bone volume. Also, OSMR(FKO) mice exhibit increased expression of Osm, the T cell markers Cd4 and Cd8, and the macrophage markers F4/80 and Cd11c Interestingly, the same proinflammatory genes induced by OSM in adipocytes are induced in the adipose tissue of the OSMR(FKO) mouse, suggesting that increased expression of proinflammatory genes in adipose tissue arises both from adipocytes and other cell types. These findings suggest that adipocyte OSMR signaling is involved in the regulation of adipose tissue homeostasis and that, in obesity, OSMR ablation may exacerbate insulin resistance by promoting adipose tissue inflammation.

  7. Adipose tissue supports normalization of macrophage and liver lipid handling in obesity reversal.

    PubMed

    Vatarescu, Maayan; Bechor, Sapir; Haim, Yulia; Pecht, Tal; Tarnovscki, Tanya; Slutsky, Noa; Nov, Ori; Shapiro, Hagit; Shemesh, Avishai; Porgador, Angel; Bashan, Nava; Rudich, Assaf

    2017-06-01

    Adipose tissue inflammation and dysfunction are considered central in the pathogenesis of obesity-related dysmetabolism, but their role in the rapid metabolic recovery upon obesity reversal is less well defined. We hypothesized that changes in adipose tissue endocrine and paracrine mechanisms may support the rapid improvement of obesity-induced impairment in cellular lipid handling. C57Bl-6J mice were fed ad libitum either normal chow (NC) or high-fat diet (HFF) for 10 weeks. A dietary obesity reversal group was fed HFF for 8 weeks and then switched to NC for 2 weeks (HFF→NC). Whole-body glucose homeostasis rapidly nearly normalized in the HFF→NC mice (fasting glucose and insulin fully normalized, glucose and insulin tolerance tests reversed 82% to the NC group levels). During 2 weeks of the dietary reversal, the liver was significantly cleared from ectopic fat, and functionally, glucose production from pyruvate, alanine or fructose was normalized. In contrast, adipose tissue inflammation (macrophage infiltration and polarization) largely remained as in HFF, though obesity-induced adipose tissue macrophage lipid accumulation decreased by ~50%, and adipose tissue MAP kinase hyperactivation was reversed. Ex vivo, mild changes in adipose tissue adipocytokine secretion profile were noted. These corresponded to partial or full reversal of the excess cellular lipid droplet accumulation induced by HFF adipose tissue conditioned media in hepatoma or macrophage cells, respectively. We propose that early after initiating reversal of nutritional obesity, rapid metabolic normalization largely precedes resolution of adipose tissue inflammation. Nevertheless, we demonstrate a hitherto unrecognized contribution of adipose tissue to the rapid improvement in lipid handling by the liver and by macrophages. © 2017 The authors.

  8. Transplantation of adipose tissue-derived stem cells overexpressing heme oxygenase-1 improves functions and remodeling of infarcted myocardium in rabbits.

    PubMed

    Yang, Jun-jie; Yang, Xia; Liu, Zhi-qiang; Hu, Shun-yin; Du, Zhi-yan; Feng, Lan-lan; Liu, Jian-feng; Chen, Yun-dai

    2012-01-01

    Adipose tissue-derived stem cells (ADSCs) are a promising source of autologous stem cells that are used for regeneration and repair of infracted heart. However, the efficiency of their transplantation is under debate. One of the possible reasons for marginal improvement in ADSCs transplantation is the significant cell death rate of implanted cells after being grafted into injured heart. Therefore, overcoming the poor survival rate of implanted cells may improve stem cell therapy. Due to limited improvement concerning direct stem cell therapy, gene-transfer methods are used to enhance cellular cardiomyoplasty efficacy. Heme oxygenase-1 (HO-1) can provide various types of cells with protection against oxidative injury and apoptosis. However, exact effects of autologous ADSCs combined with HO-1 on cardiac performance remains unknown. In this study, rabbits were treated with ADSCs transduced with HO-1 (HO-1-ADSCs), treated with non-transduced ADSCs, or injected with phosphate buffered saline 14 days after experimental myocardial infarction was induced, when autologous ADSCs were obtained simultaneously. Four weeks after injection, echocardiography showed significant improvements for cardiac functions and left ventricular dimensions in HO-1-ADSCs-treated animals. Structural consequences of transplantation were determined by detailed histological analysis, which showed differentiation of HO-1-ADSCs to cardiomyocyte-like tissues and lumen-like structure organizations. Apart from improvement in angiogenesis and scar areas, more connexin 43-positive gap junction and greater tyrosine hydroxylase-positive cardiac sympathetic nerves sprouting were observed in the HO-1-ADSCs-treated group compared with ADSCs group. These data suggest that the transplantation of autologous ADSCs combined with HO-1 transduction is a feasible and efficacious method for improving infarcted myocardium.

  9. Total DDT and dieldrin content of human adipose tissue

    SciTech Connect

    Ahmad, N.; Harsas, W.; Marolt, R.S.; Morton, M.; Pollack, J.K.

    1988-12-01

    As far as the authors could ascertain only 4 well-documented analytical studies have been carried out in Australia determining the total DDT and dieldrin content of human adipose tissue. The latest of these studies was published over 16 years ago. Therefore it is timely and important to re-examine the total DDT and dieldrin concentration within the adipose tissue of the Australian population. The present investigation has analyzed 290 samples of human adipose tissue obtained from Westmead Hospital situated in an outer suburb of Sydney, New South Wales for their content of total DDT and dieldrin.

  10. Self-synthesized extracellular matrix contributes to mature adipose tissue regeneration in a tissue engineering chamber.

    PubMed

    Zhan, Weiqing; Chang, Qiang; Xiao, Xiaolian; Dong, Ziqing; Zeng, Zhaowei; Gao, Jianhua; Lu, Feng

    2015-01-01

    The development of an engineered adipose tissue substitute capable of supporting reliable, predictable, and complete fat tissue regeneration would be of value in plastic and reconstructive surgery. For adipogenesis, a tissue engineering chamber provides an optimized microenvironment that is both efficacious and reproducible; however, for reasons that remain unclear, tissues regenerated in a tissue engineering chamber consist mostly of connective rather than adipose tissue. Here, we describe a chamber-based system for improving the yield of mature adipose tissue and discuss the potential mechanism of adipogenesis in tissue-chamber models. Adipose tissue flaps with independent vascular pedicles placed in chambers were implanted into rabbits. Adipose volume increased significantly during the observation period (week 1, 2, 3, 4, 16). Histomorphometry revealed mature adipose tissue with signs of adipose tissue remolding. The induced engineered constructs showed high-level expression of adipogenic (peroxisome proliferator-activated receptor γ), chemotactic (stromal cell-derived factor 1a), and inflammatory (interleukin 1 and 6) genes. In our system, the extracellular matrix may have served as a scaffold for cell migration and proliferation, allowing mature adipose tissue to be obtained in a chamber microenvironment without the need for an exogenous scaffold. Our results provide new insights into key elements involved in the early development of adipose tissue regeneration.

  11. Adipose Tissue: Sanctuary for HIV/SIV Persistence and Replication.

    PubMed

    Pallikkuth, Suresh; Mohan, Mahesh

    2015-12-01

    This commentary highlights new findings from a recent study identifying adipose tissue as a potential HIV reservoir and a major site of inflammation during chronic human/simian immunodeficiency virus (HIV/SIV) infection. A concise discussion about upcoming challenges and new research avenues for reducing chronic adipose inflammation during HIV/SIV infection is presented.

  12. Associations of calf inter- and intra-muscular adipose tissue with cardiometabolic health and physical function in community-dwelling older adults.

    PubMed

    Scott, D; Trbojevic, T; Skinner, E; Clark, R A; Levinger, P; Haines, T P; Sanders, K M; Ebeling, P R

    2015-12-01

    To determine associations of inter- and intra-muscular adipose tissue (IMAT) with cardiometabolic health and physical function in older adults. 48 community-dwelling older adults aged ⋝65 years (mean 71.6±4.8 years; 52% women) underwent whole-body dual-energy X-ray absorptiometry, to assess appendicular lean mass (ALM), and peripheral quantitative computed tomography (pQCT; 66% tibia), to assess calf IMAT cross-sectional area ([CSA]; cm2) and muscle density (mg/cm(3); higher values indicate lower fat infiltration). Fasting glucose, lipids, triglycerides and C-reactive protein (CRP) were analysed. Physical function was assessed by postural sway (computerised posturography; N=41), and gait analysis (GAITRite Electronic Walkway; N=40). Higher IMAT CSA and muscle density were associated with significantly higher (B=0.85 95%CI [0.34, 1.36]) and lower (-2.14 [-4.20, -0.08]) CRP and higher (0.93 [0.56, 1.30]) and lower postural sway (-3.12 [-4.74, -1.50]), respectively, after adjustment for age, sex and ALM/BMI. Higher IMAT CSA was associated with slower gait speed and cadence, and greater step time and step width (all P<0.03), while higher muscle density was associated with smaller step width (P<0.01) only. Older adults with higher calf IMAT have poorer balance, mobility and inflammatory status. Interventions aimed at improving physical function in older adults should incorporate strategies to reduce IMAT.

  13. Transplantation of adipose tissue-derived stem cells improves cardiac contractile function and electrical stability in a rat myocardial infarction model.

    PubMed

    Gautam, Milan; Fujita, Daiki; Kimura, Kazuhiro; Ichikawa, Hinako; Izawa, Atsushi; Hirose, Masamichi; Kashihara, Toshihide; Yamada, Mitsuhiko; Takahashi, Masafumi; Ikeda, Uichi; Shiba, Yuji

    2015-04-01

    The transplantation of adipose tissue-derived stem cells (ADSCs) improves cardiac contractility after myocardial infarction (MI); however, little is known about the electrophysiological consequences of transplantation. The purpose of this study was to clarify whether the transplantation of ADSCs increases or decreases the incidence of ventricular tachyarrhythmias (VT) in a rat model of MI. MI was induced experimentally by permanent occlusion of the left anterior descending artery of Lewis rats. ADSCs were harvested from GFP-transgenic rats, and were cultured until passage four. ADSCs (10×10(6)) resuspended in 100μL saline or pro-survival cocktail (PSC), which enhances cardiac graft survival, were injected directly into syngeneic rat hearts 1week after MI. The recipients of ADSCs suspended in PSC had a larger graft area compared with those receiving ASDCs suspended in saline at 1week post-transplantation (number of graft cells/section: 148.7±10.6 vs. 22.4±3.4, p<0.05, n=5/group). Thereafter, all ADSC recipients were transplanted with ASDCs in PSC. ADSCs were transplanted into infarcted hearts, and the mechanical and electrophysiological functions were assessed. Echocardiography revealed that ADSC recipients had improved contractile function compared with those receiving PSC vehicle (fractional shortening: 21.1±0.9 vs. 14.1±1.2, p<0.05, n≥12/group). Four weeks post-transplantation, VT was induced via in vivo programmed electrical stimulation. The recipients of ADSCs showed a significantly lower incidence of induced VT compared with the control (31.3% vs. 83.3%, p<0.05, n≥12/group). To understand the electrical activity following transplantation, we performed ex vivo optical mapping using a voltage sensitive dye, and found that ADSC transplantation decreased conduction velocity and its dispersion in the peri-infarct area. These results suggest that ADSC transplantation improved cardiac mechanical and electrophysiological functions in subacute MI.

  14. Long noncoding RNA repertoire in chicken liver and adipose tissue.

    PubMed

    Muret, Kévin; Klopp, Christophe; Wucher, Valentin; Esquerré, Diane; Legeai, Fabrice; Lecerf, Frédéric; Désert, Colette; Boutin, Morgane; Jehl, Frédéric; Acloque, Hervé; Giuffra, Elisabetta; Djebali, Sarah; Foissac, Sylvain; Derrien, Thomas; Lagarrigue, Sandrine

    2017-01-10

    Improving functional annotation of the chicken genome is a key challenge in bridging the gap between genotype and phenotype. Among all transcribed regions, long noncoding RNAs (lncRNAs) are a major component of the transcriptome and its regulation, and whole-transcriptome sequencing (RNA-Seq) has greatly improved their identification and characterization. We performed an extensive profiling of the lncRNA transcriptome in the chicken liver and adipose tissue by RNA-Seq. We focused on these two tissues because of their importance in various economical traits for which energy storage and mobilization play key roles and also because of their high cell homogeneity. To predict lncRNAs, we used a recently developed tool called FEELnc, which also classifies them with respect to their distance and strand orientation to the closest protein-coding genes. Moreover, to confidently identify the genes/transcripts expressed in each tissue (a complex task for weakly expressed molecules such as lncRNAs), we probed a particularly large number of biological replicates (16 per tissue) compared to common multi-tissue studies with a larger set of tissues but less sampling. We predicted 2193 lncRNA genes, among which 1670 were robustly expressed across replicates in the liver and/or adipose tissue and which were classified into 1493 intergenic and 177 intragenic lncRNAs located between and within protein-coding genes, respectively. We observed similar structural features between chickens and mammals, with strong synteny conservation but without sequence conservation. As previously reported, we confirm that lncRNAs have a lower and more tissue-specific expression than mRNAs. Finally, we showed that adjacent lncRNA-mRNA genes in divergent orientation have a higher co-expression level when separated by less than 1 kb compared to more distant divergent pairs. Among these, we highlighted for the first time a novel lncRNA candidate involved in lipid metabolism, lnc_DHCR24, which is highly

  15. Bonghan system as mesenchymal stem cell niches and pathways of macrophages in adipose tissues.

    PubMed

    Lee, Byung-Cheon; Bae, Kyung-Hee; Jhon, Gil-Ja; Soh, Kwang-Sup

    2009-03-01

    A new technique for visualizing Bonghan ducts (BHDs) and Bonghan corpuscles (BHCs) was developed by using a vivi-staining dye, Trypan blue. The dye stains BHDs and BHCs preferentially to adipocytes so that tracking a BHD and a BHC, even inside adipose tissues, is possible. Concerning the functions of the BHD and the BHC in adipose tissues, we propose conjectures: the Bonghan system may be niches for mesenchymal stem cells, which can differentiate into adipocytes, and pathways for macrophages involved in adipogenesis.

  16. Isoliquiritigenin Attenuates Adipose Tissue Inflammation in vitro and Adipose Tissue Fibrosis through Inhibition of Innate Immune Responses in Mice

    PubMed Central

    Watanabe, Yasuharu; Nagai, Yoshinori; Honda, Hiroe; Okamoto, Naoki; Yamamoto, Seiji; Hamashima, Takeru; Ishii, Yoko; Tanaka, Miyako; Suganami, Takayoshi; Sasahara, Masakiyo; Miyake, Kensuke; Takatsu, Kiyoshi

    2016-01-01

    Isoliquiritigenin (ILG) is a flavonoid derived from Glycyrrhiza uralensis and potently suppresses NLRP3 inflammasome activation resulting in the improvement of diet-induced adipose tissue inflammation. However, whether ILG affects other pathways besides the inflammasome in adipose tissue inflammation is unknown. We here show that ILG suppresses adipose tissue inflammation by affecting the paracrine loop containing saturated fatty acids and TNF-α by using a co-culture composed of adipocytes and macrophages. ILG suppressed inflammatory changes induced by the co-culture through inhibition of NF-κB activation. This effect was independent of either inhibition of inflammasome activation or activation of peroxisome proliferator-activated receptor-γ. Moreover, ILG suppressed TNF-α-induced activation of adipocytes, coincident with inhibition of IκBα phosphorylation. Additionally, TNF-α-mediated inhibition of Akt phosphorylation under insulin signaling was alleviated by ILG in adipocytes. ILG suppressed palmitic acid-induced activation of macrophages, with decreasing the level of phosphorylated Jnk expression. Intriguingly, ILG improved high fat diet-induced fibrosis in adipose tissue in vivo. Finally, ILG inhibited TLR4- or Mincle-stimulated expression of fibrosis-related genes in stromal vascular fraction from obese adipose tissue and macrophages in vitro. Thus, ILG can suppress adipose tissue inflammation by both inflammasome-dependent and -independent manners and attenuate adipose tissue fibrosis by targeting innate immune sensors. PMID:26975571

  17. Improvement of adipose tissue-derived cells by low-energy extracorporeal shock wave therapy.

    PubMed

    Priglinger, Eleni; Schuh, Christina M A P; Steffenhagen, Carolin; Wurzer, Christoph; Maier, Julia; Nuernberger, Sylvia; Holnthoner, Wolfgang; Fuchs, Christiane; Suessner, Susanne; Rünzler, Dominik; Redl, Heinz; Wolbank, Susanne

    2017-09-01

    Cell-based therapies with autologous adipose tissue-derived cells have shown great potential in several clinical studies in the last decades. The majority of these studies have been using the stromal vascular fraction (SVF), a heterogeneous mixture of fibroblasts, lymphocytes, monocytes/macrophages, endothelial cells, endothelial progenitor cells, pericytes and adipose-derived stromal/stem cells (ASC) among others. Although possible clinical applications of autologous adipose tissue-derived cells are manifold, they are limited by insufficient uniformity in cell identity and regenerative potency. In our experimental set-up, low-energy extracorporeal shock wave therapy (ESWT) was performed on freshly obtained human adipose tissue and isolated adipose tissue SVF cells aiming to equalize and enhance stem cell properties and functionality. After ESWT on adipose tissue we could achieve higher cellular adenosine triphosphate (ATP) levels compared with ESWT on the isolated SVF as well as the control. ESWT on adipose tissue resulted in a significantly higher expression of single mesenchymal and vascular marker compared with untreated control. Analysis of SVF protein secretome revealed a significant enhancement in insulin-like growth factor (IGF)-1 and placental growth factor (PLGF) after ESWT on adipose tissue. Summarizing we could show that ESWT on adipose tissue enhanced the cellular ATP content and modified the expression of single mesenchymal and vascular marker, and thus potentially provides a more regenerative cell population. Because the effectiveness of autologous cell therapy is dependent on the therapeutic potency of the patient's cells, this technology might raise the number of patients eligible for autologous cell transplantation. Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  18. Soya protein attenuates abnormalities of the renin-angiotensin system in adipose tissue from obese rats.

    PubMed

    Frigolet, María E; Torres, Nimbe; Tovar, Armando R

    2012-01-01

    Several metabolic disturbances during obesity are associated with adipose tissue-altered functions. Adipocytes contain the renin-angiotensin system (RAS), which regulates signalling pathways that control angiogenesis via Akt in an autocrine fashion. Soya protein (Soy) consumption modifies the gene expression pattern in adipose tissue, resulting in an improved adipocyte function. Therefore, the aim of the present work is to study whether dietary Soy regulates the expression of RAS and angiogenesis-related genes and its association with the phosphorylated state of Akt in the adipose tissue of obese rats. Animals were fed a 30 % Soy or casein (Cas) diet containing 5 or 25 % fat for 160 d. mRNA abundance was studied in the adipose tissue, and Akt phosphorylation and hormone release were measured in the primary adipocyte culture. The present results show that Soy treatment in comparison with Cas consumption induces lower angiotensin release and increased insulin-stimulated Akt activation in adipocytes. Furthermore, Soy consumption varies the expression of RAS and angiogenesis-related genes, which maintain cell size and vascularity in the adipose tissue of rats fed a high-fat diet. Thus, adipocyte hypertrophy and impaired angiogenesis, which are frequently observed in dysfunctional adipose tissue, were avoided by consuming dietary Soy. Taken together, these findings suggest that Soy can be used as a dietary strategy to preserve adipocyte functionality and to prevent obesity abnormalities.

  19. Adipose tissue lymphocytes: types and roles.

    PubMed

    Caspar-Bauguil, S; Cousin, B; Bour, S; Casteilla, L; Castiella, L; Penicaud, L; Carpéné, C

    2009-12-01

    Besides adipocytes, specialized in lipid handling and involved in energy balance regulation, white adipose tissue (WAT) is mainly composed of other cell types among which lymphocytes represent a non-negligible proportion. Different types of lymphocytes (B, alphabetaT, gammadeltaT, NK and NKT) have been detected in WAT of rodents or humans, and vary in their relative proportion according to the fat pad anatomical location. The lymphocytes found in intra-abdominal, visceral fat pads seem representative of innate immunity, while those present in subcutaneous fat depots are part of adaptive immunity, at least in mice. Both the number and the activity of the different lymphocyte classes, except B lymphocytes, are modified in obesity. Several of these modifications in the relative proportions of the lymphocyte classes depend on the degree of obesity, or on leptin concentration, or even fat depot anatomical location. Recent studies suggest that alterations of lymphocyte number and composition precede the macrophage increase and the enhanced inflammatory state of WAT found in obesity. Lymphocytes express receptors to adipokines while several proinflammatory chemokines are produced in WAT, rendering intricate crosstalk between fat and immune cells. However, the evidences and controversies available so far are in favour of an involvement of lymphocytes in the control of the number of other cells in WAT, either adipocytes or immune cells and of their secretory and metabolic activities. Therefore, immunotherapy deserves to be considered as a promising approach to treat the endocrino-metabolic disorders associated to excessive fat mass development.

  20. Hypothalamic control of brown adipose tissue thermogenesis

    PubMed Central

    Labbé, Sebastien M.; Caron, Alexandre; Lanfray, Damien; Monge-Rofarello, Boris; Bartness, Timothy J.; Richard, Denis

    2015-01-01

    It has long been known, in large part from animal studies, that the control of brown adipose tissue (BAT) thermogenesis is insured by the central nervous system (CNS), which integrates several stimuli in order to control BAT activation through the sympathetic nervous system (SNS). SNS-mediated BAT activity is governed by diverse neurons found in brain structures involved in homeostatic regulations and whose activity is modulated by various factors including oscillations of energy fluxes. The characterization of these neurons has always represented a challenging issue. The available literature suggests that the neuronal circuits controlling BAT thermogenesis are largely part of an autonomic circuitry involving the hypothalamus, brainstem and the SNS efferent neurons. In the present review, we recapitulate the latest progresses in regards to the hypothalamic regulation of BAT metabolism. We briefly addressed the role of the thermoregulatory pathway and its interactions with the energy balance systems in the control of thermogenesis. We also reviewed the involvement of the brain melanocortin and endocannabinoid systems as well as the emerging role of steroidogenic factor 1 (SF1) neurons in BAT thermogenesis. Finally, we examined the link existing between these systems and the homeostatic factors that modulate their activities. PMID:26578907

  1. Central Control of Brown Adipose Tissue Thermogenesis

    PubMed Central

    Morrison, Shaun F.; Madden, Christopher J.; Tupone, Domenico

    2011-01-01

    Thermogenesis, the production of heat energy, is an essential component of the homeostatic repertoire to maintain body temperature during the challenge of low environmental temperature and plays a key role in elevating body temperature during the febrile response to infection. Mitochondrial oxidation in brown adipose tissue (BAT) is a significant source of neurally regulated metabolic heat production in many species from mouse to man. BAT thermogenesis is regulated by neural networks in the central nervous system which responds to feedforward afferent signals from cutaneous and core body thermoreceptors and to feedback signals from brain thermosensitive neurons to activate BAT sympathetic nerve activity. This review summarizes the research leading to a model of the feedforward reflex pathway through which environmental cold stimulates BAT thermogenesis and includes the influence on this thermoregulatory network of the pyrogenic mediator, prostaglandin E2, to increase body temperature during fever. The cold thermal afferent circuit from cutaneous thermal receptors, through second-order thermosensory neurons in the dorsal horn of the spinal cord ascends to activate neurons in the lateral parabrachial nucleus which drive GABAergic interneurons in the preoptic area (POA) to inhibit warm-sensitive, inhibitory output neurons of the POA. The resulting disinhibition of BAT thermogenesis-promoting neurons in the dorsomedial hypothalamus activates BAT sympathetic premotor neurons in the rostral ventromedial medulla, including the rostral raphe pallidus, which provide excitatory, and possibly disinhibitory, inputs to spinal sympathetic circuits to drive BAT thermogenesis. Other recently recognized central sites influencing BAT thermogenesis and energy expenditure are also described. PMID:22389645

  2. Automated segmentation of abdominal subcutaneous adipose tissue and visceral adipose tissue in obese adolescent in MRI.

    PubMed

    Hui, Steve C N; Zhang, Teng; Shi, Lin; Wang, Defeng; Ip, Chei-Bing; Chu, Winnie C W

    2017-10-07

    To develop a reliable and reproducible automatic technique to segment and measure SAT and VAT based on MRI. Chemical-shift water-fat MRI were taken on twelve obese adolescents (mean age: 16.1±0.6, BMI: 31.3±2.3) recruited under the health monitoring program. The segmentation applied a spoke template created using Midpoint Circle algorithm followed by Bresenham's Line algorithm to detect narrow connecting regions between subcutaneous and visceral adipose tissues. Upon satisfaction of given constrains, a cut was performed to separate SAT and VAT. Bone marrow was consisted in pelvis and femur. By using the intensity difference in T2*, a mask was created to extract bone marrow adipose tissue (MAT) from VAT. Validation was performed using a semi-automatic method. Pearson coefficient, Bland-Altman plot and intra-class coefficient (ICC) were applied to measure accuracy and reproducibility. Pearson coefficient indicated that results from the proposed method achieved high correlation with the semi-automatic method. Bland-Altman plot and ICC showed good agreement between the two methods. Lowest ICC was obtained in VAT segmentation at lower regions of the abdomen while the rests were all above 0.80. ICC (0.98-0.99) also indicated the proposed method performed good reproducibility. No user interaction was required during execution of the algorithm and the segmented images and volume results were given as output. This technique utilized the feature in the regions connecting subcutaneous and visceral fat and T2* intensity difference in bone marrow to achieve volumetric measurement of various types of adipose tissue in abdominal site. Copyright © 2017. Published by Elsevier Inc.

  3. Isolation and Differentiation of Adipose-Derived Stem Cells from Porcine Subcutaneous Adipose Tissues.

    PubMed

    Chen, Yu-Jen; Liu, Hui-Yu; Chang, Yun-Tsui; Cheng, Ying-Hung; Mersmann, Harry J; Kuo, Wen-Hung; Ding, Shih-Torng

    2016-03-31

    Obesity is an unconstrained worldwide epidemic. Unraveling molecular controls in adipose tissue development holds promise to treat obesity or diabetes. Although numerous immortalized adipogenic cell lines have been established, adipose-derived stem cells from the stromal vascular fraction of subcutaneous white adipose tissues provide a reliable cellular system ex vivo much closer to adipose development in vivo. Pig adipose-derived stem cells (pADSC) are isolated from 7- to 9-day old piglets. The dorsal white fat depot of porcine subcutaneous adipose tissues is sliced, minced and collagenase digested. These pADSC exhibit strong potential to differentiate into adipocytes. Moreover, the pADSC also possess multipotency, assessed by selective stem cell markers, to differentiate into various mesenchymal cell types including adipocytes, osteocytes, and chondrocytes. These pADSC can be used for clarification of molecular switches in regulating classical adipocyte differentiation or in direction to other mesenchymal cell types of mesodermal origin. Furthermore, extended lineages into cells of ectodermal and endodermal origin have recently been achieved. Therefore, pADSC derived in this protocol provide an abundant and assessable source of adult mesenchymal stem cells with full multipotency for studying adipose development and application to tissue engineering of regenerative medicine.

  4. Cell autonomous lipin 1 function is essential for development and maintenance of white and brown adipose tissue.

    PubMed

    Nadra, Karim; Médard, Jean-Jacques; Mul, Joram D; Han, Gil-Soo; Grès, Sandra; Pende, Mario; Metzger, Daniel; Chambon, Pierre; Cuppen, Edwin; Saulnier-Blache, Jean-Sébastien; Carman, George M; Desvergne, Béatrice; Chrast, Roman

    2012-12-01

    Through analysis of mice with spatially and temporally restricted inactivation of Lpin1, we characterized its cell autonomous function in both white (WAT) and brown (BAT) adipocyte development and maintenance. We observed that the lipin 1 inactivation in adipocytes of aP2(Cre/+)/Lp(fEx2)(-)(3/fEx2)(-)(3) mice resulted in lipodystrophy and the presence of adipocytes with multilocular lipid droplets. We further showed that time-specific loss of lipin 1 in mature adipocytes in aP2(Cre-ERT2/+)/Lp(fEx2)(-)(3/fEx2)(-)(3) mice led to their replacement by newly formed Lpin1-positive adipocytes, thus establishing a role for lipin 1 in mature adipocyte maintenance. Importantly, we observed that the presence of newly formed Lpin1-positive adipocytes in aP2(Cre-ERT2/+)/Lp(fEx2)(-)(3/fEx2)(-)(3) mice protected these animals against WAT inflammation and hepatic steatosis induced by a high-fat diet. Loss of lipin 1 also affected BAT development and function, as revealed by histological changes, defects in the expression of peroxisome proliferator-activated receptor alpha (PPARα), PGC-1α, and UCP1, and functionally by altered cold sensitivity. Finally, our data indicate that phosphatidic acid, which accumulates in WAT of animals lacking lipin 1 function, specifically inhibits differentiation of preadipocytes. Together, these observations firmly demonstrate a cell autonomous role of lipin 1 in WAT and BAT biology and indicate its potential as a therapeutical target for the treatment of obesity.

  5. Cell Autonomous Lipin 1 Function Is Essential for Development and Maintenance of White and Brown Adipose Tissue

    PubMed Central

    Médard, Jean-Jacques; Mul, Joram D.; Han, Gil-Soo; Grès, Sandra; Pende, Mario; Metzger, Daniel; Chambon, Pierre; Cuppen, Edwin; Saulnier-Blache, Jean-Sébastien; Carman, George M.; Desvergne, Béatrice

    2012-01-01

    Through analysis of mice with spatially and temporally restricted inactivation of Lpin1, we characterized its cell autonomous function in both white (WAT) and brown (BAT) adipocyte development and maintenance. We observed that the lipin 1 inactivation in adipocytes of aP2Cre/+/LpfEx2-3/fEx2-3 mice resulted in lipodystrophy and the presence of adipocytes with multilocular lipid droplets. We further showed that time-specific loss of lipin 1 in mature adipocytes in aP2Cre-ERT2/+/LpfEx2-3/fEx2-3 mice led to their replacement by newly formed Lpin1-positive adipocytes, thus establishing a role for lipin 1 in mature adipocyte maintenance. Importantly, we observed that the presence of newly formed Lpin1-positive adipocytes in aP2Cre-ERT2/+/LpfEx2-3/fEx2-3 mice protected these animals against WAT inflammation and hepatic steatosis induced by a high-fat diet. Loss of lipin 1 also affected BAT development and function, as revealed by histological changes, defects in the expression of peroxisome proliferator-activated receptor alpha (PPARα), PGC-1α, and UCP1, and functionally by altered cold sensitivity. Finally, our data indicate that phosphatidic acid, which accumulates in WAT of animals lacking lipin 1 function, specifically inhibits differentiation of preadipocytes. Together, these observations firmly demonstrate a cell autonomous role of lipin 1 in WAT and BAT biology and indicate its potential as a therapeutical target for the treatment of obesity. PMID:23028044

  6. Metabolic syndrome pathophysiology: the role of adipose tissue

    USDA-ARS?s Scientific Manuscript database

    Several physiopathological explanations for the metabolic syndrome have been proposed involving insulin resistance, chronic inflammation and ectopic fat accumulation following adipose tissue saturation. However, current concepts create several paradoxes, including limited cardiovascular risk reducti...

  7. Adipose tissue inflammation and metabolic dysfunction: a clinical perspective.

    PubMed

    Tam, Charmaine S; Redman, Leanne M

    2013-09-01

    Obesity is characterized by a state of chronic low-grade inflammation due to increased immune cells, specifically infiltrated macrophages into adipose tissue, which in turn secrete a range of proinflammatory mediators. This nonselective low-grade inflammation of adipose tissue is systemic in nature and can impair insulin signaling pathways, thus, increasing the risk of developing insulin resistance and type 2 diabetes. The aim of this review is to provide an update on clinical studies examining the role of adipose tissue in the development of obesity-associated complications in humans. We will discuss adipose tissue inflammation during different scenarios of energy imbalance and metabolic dysfunction including obesity and overfeeding, weight loss by calorie restriction or bariatric surgery, and conditions of insulin resistance (diabetes, polycystic ovarian syndrome).

  8. Segmentation and quantification of adipose tissue by magnetic resonance imaging

    PubMed Central

    Chen, Jun; Shen, Wei

    2016-01-01

    In this brief review, introductory concepts in animal and human adipose tissue segmentation using proton magnetic resonance imaging (MRI) and computed tomography are summarized in the context of obesity research. Adipose tissue segmentation and quantification using spin relaxation-based (e.g., T1-weighted, T2-weighted), relaxometry-based (e.g., T1-, T2-, T2*-mapping), chemical-shift selective, and chemical-shift encoded water–fat MRI pulse sequences are briefly discussed. The continuing interest to classify subcutaneous and visceral adipose tissue depots into smaller sub-depot compartments is mentioned. The use of a single slice, a stack of slices across a limited anatomical region, or a whole body protocol is considered. Common image post-processing steps and emerging atlas-based automated segmentation techniques are noted. Finally, the article identifies some directions of future research, including a discussion on the growing topic of brown adipose tissue and related segmentation considerations. PMID:26336839

  9. Adipose tissue in obesity-related inflammation and insulin resistance: cells, cytokines, and chemokines.

    PubMed

    Makki, Kassem; Froguel, Philippe; Wolowczuk, Isabelle

    2013-12-22

    Adipose tissue is a complex organ that comprises a wide range of cell types with diverse energy storage, metabolic regulation, and neuroendocrine and immune functions. Because it contains various immune cells, either adaptive (B and T lymphocytes; such as regulatory T cells) or innate (mostly macrophages and, more recently identified, myeloid-derived suppressor cells), the adipose tissue is now considered as a bona fide immune organ, at the cross-road between metabolism and immunity. Adipose tissue disorders, such as those encountered in obesity and lipodystrophy, cause alterations to adipose tissue distribution and function with broad effects on cytokine, chemokine, and hormone expression, on lipid storage, and on the composition of adipose-resident immune cell populations. The resulting changes appear to induce profound consequences for basal systemic inflammation and insulin sensitivity. The purpose of this review is to synthesize the current literature on adipose cell composition remodeling in obesity, which shows how adipose-resident immune cells regulate inflammation and insulin resistance-notably through cytokine and chemokine secretion-and highlights major research questions in the field.

  10. Hepatic ANGPTL3 regulates adipose tissue energy homeostasis

    PubMed Central

    Wang, Yan; McNutt, Markey C.; Banfi, Serena; Levin, Michael G.; Holland, William L.; Gusarova, Viktoria; Gromada, Jesper; Cohen, Jonathan C.; Hobbs, Helen H.

    2015-01-01

    Angiopoietin-like protein 3 (ANGPTL3) is a circulating inhibitor of lipoprotein and endothelial lipase whose physiological function has remained obscure. Here we show that ANGPTL3 plays a major role in promoting uptake of circulating very low density lipoprotein-triglycerides (VLDL-TGs) into white adipose tissue (WAT) rather than oxidative tissues (skeletal muscle, heart brown adipose tissue) in the fed state. This conclusion emerged from studies of Angptl3−/− mice. Whereas feeding increased VLDL-TG uptake into WAT eightfold in wild-type mice, no increase occurred in fed Angptl3−/− animals. Despite the reduction in delivery to and retention of TG in WAT, fat mass was largely preserved by a compensatory increase in de novo lipogenesis in Angptl3−/− mice. Glucose uptake into WAT was increased 10-fold in KO mice, and tracer studies revealed increased conversion of glucose to fatty acids in WAT but not liver. It is likely that the increased uptake of glucose into WAT explains the increased insulin sensitivity associated with inactivation of ANGPTL3. The beneficial effects of ANGPTL3 deficiency on both glucose and lipoprotein metabolism make it an attractive therapeutic target. PMID:26305978

  11. The renin-angiotensin system in adipose tissue and its metabolic consequences during obesity.

    PubMed

    Frigolet, Maria E; Torres, Nimbe; Tovar, Armando R

    2013-12-01

    Obesity is a worldwide disease that is accompanied by several metabolic abnormalities such as hypertension, hyperglycemia and dyslipidemia. The accelerated adipose tissue growth and fat cell hypertrophy during the onset of obesity precedes adipocyte dysfunction. One of the features of adipocyte dysfunction is dysregulated adipokine secretion, which leads to an imbalance of pro-inflammatory, pro-atherogenic versus anti-inflammatory, insulin-sensitizing adipokines. The production of renin-angiotensin system (RAS) components by adipocytes is exacerbated during obesity, contributing to the systemic RAS and its consequences. Increased adipose tissue RAS has been described in various models of diet-induced obesity (DIO) including fructose and high-fat feeding. Up-regulation of the adipose RAS by DIO promotes inflammation, lipogenesis and reactive oxygen species generation and impairs insulin signaling, all of which worsen the adipose environment. Consequently, the increase of circulating RAS, for which adipose tissue is partially responsible, represents a link between hypertension, insulin resistance in diabetes and inflammation during obesity. However, other nutrients and food components such as soy protein attenuate adipose RAS, decrease adiposity, and improve adipocyte functionality. Here, we review the molecular mechanisms by which adipose RAS modulates systemic RAS and how it is enhanced in obesity, which will explain the simultaneous development of metabolic syndrome alterations. Finally, dietary interventions that prevent obesity and adipocyte dysfunction will maintain normal RAS concentrations and effects, thus preventing metabolic diseases that are associated with RAS enhancement. © 2013.

  12. [The adipose tissue of the orbit. Anatomic classification, therapeutic deductions].

    PubMed

    Gola, R; Carreau, J P; Faissal, A

    1995-01-01

    There are two types of adipose tissue in the orbit. The yellow fat and the more abundant white, or orbital fat. Orbital fat cannot be dissociated from the contents of the orbit and plays an important role in ocular physiology and oculomotricity. Orbital fat is essential for aesthetic orbits. Graves' disease and anophthalmia. Adipose tissue in the orbit is particularly important in protecting the ocular globe from lateral wall trauma.

  13. THE POTENTIAL ROLES FOR ADIPOSE TISSUE IN PERIPHERAL NERVE REGENERATION

    PubMed Central

    Walocko, Frances M.; Khouri, Roger K.; Urbanchek, Melanie G.; Levi, Benjamin; Cederna, Paul S.

    2016-01-01

    Introduction This review summarizes current understanding about the role of adipose-derived tissues in peripheral nerve regeneration and discusses potential advances that would translate this approach into the clinic. Methods We searched PubMed for in vivo, experimental studies on the regenerative effects of adipose-derived tissues on peripheral nerve injuries. We summarized the methods and results for the 42 experiments. Results Adipose-derived tissues enhanced peripheral nerve regeneration in 86% of the experiments. Ninety-five percent evaluated purified, cultured, or differentiated adipose tissue. These approaches have regulatory and scaling burdens, restricting clinical usage. Only one experiment tested the ability of adipose tissue to enhance nerve regeneration in conjunction with nerve autografts, the clinical gold standard. Conclusion Scientific studies illustrate that adipose-derived tissues enhance regeneration of peripheral nerves. Before this approach achieves clinical acceptance, fat processing must become automated and regulatory approval achieved. Animal studies using whole fat grafts are greatly needed for clinical translation. PMID:26773850

  14. HOXC10 suppresses browning of white adipose tissues

    PubMed Central

    Ng, Yvonne; Tan, Shi-Xiong; Chia, Sook Yoong; Tan, Hwee Yim Angeline; Gun, Sin Yee; Sun, Lei; Hong, Wanjin; Han, Weiping

    2017-01-01

    Given that increased thermogenesis in white adipose tissue, also known as browning, promotes energy expenditure, significant efforts have been invested to determine the molecular factors involved in this process. Here we show that HOXC10, a homeobox domain-containing transcription factor expressed in subcutaneous white adipose tissue, is a suppressor of genes involved in browning white adipose tissue. Ectopic expression of HOXC10 in adipocytes suppresses brown fat genes, whereas the depletion of HOXC10 in adipocytes and myoblasts increases the expression of brown fat genes. The protein level of HOXC10 inversely correlates with brown fat genes in subcutaneous white adipose tissue of cold-exposed mice. Expression of HOXC10 in mice suppresses cold-induced browning in subcutaneous white adipose tissue and abolishes the beneficial effect of cold exposure on glucose clearance. HOXC10 exerts its effect, at least in part, by suppressing PRDM16 expression. The results support that HOXC10 is a key negative regulator of the process of browning in white adipose tissue. PMID:28186086

  15. Recovery of renal function after administration of adipose-tissue-derived stromal vascular fraction in rat model of acute kidney injury induced by ischemia/reperfusion injury.

    PubMed

    Lee, Chunwoo; Jang, Myoung Jin; Kim, Bo Hyun; Park, Jin Young; You, Dalsan; Jeong, In Gab; Hong, Jun Hyuk; Kim, Choung-Soo

    2017-03-10

    Acute kidney injury (AKI) induced by ischemia/reperfusion (I/R) injury is a major challenge in critical care medicine. The purpose of this study is to determine the therapeutic effects of the adipose-tissue-derived stromal vascular fraction (SVF) and the optimal route for SVF delivery in a rat model of AKI induced by I/R injury. Fifty male Sprague-Dawley rats were randomly divided into five groups (10 animals per group): sham, nephrectomy control, I/R injury control, renal arterial SVF infusion and subcapsular SVF injection. To induce AKI by I/R injury, the left renal artery was clamped with a nontraumatic vascular clamp for 40 min, and the right kidney was removed. Rats receiving renal arterial infusion of SVF had a significantly reduced increase in serum creatinine compared with the I/R injury control group at 4 days after I/R injury. The glomerular filtration rate of the renal arterial SVF infusion group was maintained at a level similar to that of the sham and nephrectomy control groups at 14 days after I/R injury. Masson's trichrome staining showed significantly less fibrosis in the renal arterial SVF infusion group compared with that in the I/R injury control group in the outer stripe (P < 0.001). TUNEL labeling showed significantly decreased apoptosis in both the renal arterial SVF infusion and subcapsular SVF injection groups compared with the I/R injury control group in the outer stripe (P < 0.001). Thus, renal function is effectively rescued from AKI induced by I/R injury through the renal arterial administration of SVF in a rat model.

  16. Visceral adipose tissue but not subcutaneous adipose tissue is associated with urine and serum metabolites.

    PubMed

    Schlecht, Inga; Gronwald, Wolfram; Behrens, Gundula; Baumeister, Sebastian E; Hertel, Johannes; Hochrein, Jochen; Zacharias, Helena U; Fischer, Beate; Oefner, Peter J; Leitzmann, Michael F

    2017-01-01

    Obesity is a complex multifactorial phenotype that influences several metabolic pathways. Yet, few studies have examined the relations of different body fat compartments to urinary and serum metabolites. Anthropometric phenotypes (visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), the ratio between VAT and SAT (VSR), body mass index (BMI), waist circumference (WC)) and urinary and serum metabolite concentrations measured by nuclear magnetic resonance spectroscopy were measured in a population-based sample of 228 healthy adults. Multivariable linear and logistic regression models, corrected for multiple testing using the false discovery rate, were used to associate anthropometric phenotypes with metabolites. We adjusted for potential confounding variables: age, sex, smoking, physical activity, menopausal status, estimated glomerular filtration rate (eGFR), urinary glucose, and fasting status. In a fully adjusted logistic regression model dichotomized for the absence or presence of quantifiable metabolite amounts, VAT, BMI and WC were inversely related to urinary choline (ß = -0.18, p = 2.73*10-3), glycolic acid (ß = -0.20, 0.02), and guanidinoacetic acid (ß = -0.12, p = 0.04), and positively related to ethanolamine (ß = 0.18, p = 0.02) and dimethylamine (ß = 0.32, p = 0.02). BMI and WC were additionally inversely related to urinary glutamine and lactic acid. Moreover, WC was inversely associated with the detection of serine. VAT, but none of the other anthropometric parameters, was related to serum essential amino acids, such as valine, isoleucine, and phenylalanine among men. Compared to other adiposity measures, VAT demonstrated the strongest and most significant relations to urinary and serum metabolites. The distinct relations of VAT, SAT, VSR, BMI, and WC to metabolites emphasize the importance of accurately differentiating between body fat compartments when evaluating the potential role of metabolic regulation in the development of obesity

  17. Endogenous ways to stimulate brown adipose tissue in humans.

    PubMed

    Broeders, Evie; Bouvy, Nicole D; van Marken Lichtenbelt, Wouter D

    2015-03-01

    Obesity is the result of disequilibrium between energy intake and energy expenditure (EE). Successful long-term weight loss is difficult to achieve with current strategies for the correction of this caloric imbalance. Non-shivering thermogenesis (NST) in brown adipose tissue (BAT) is a possible therapeutic target for the prevention and treatment of obesity and associated metabolic diseases. In recent years, more knowledge about the function and stimulation of bat has been obtained. The sympathetic nervous system (SNS) is currently seen as the main effector for brown fat function. Also, interplay between the thyroid axis and SNS plays an important role in BAT thermogenesis. Almost daily new pathways for the induction of BAT thermogenesis and 'browning' of white adipose tissue (WAT) are identified. Especially the activation of BAT via endogenous pathways has received strong scientific attention. Here we will discuss the relevance of several pathways in activating BAT and their implications for the treatment of obesity. In this review we will focus on the discussion of the most promising endocrine and paracrine pathways to stimulate BAT, by factors and pathways that naturally occur in the human body.

  18. Adipose Natural Killer Cells Regulate Adipose Tissue Macrophages to Promote Insulin Resistance in Obesity.

    PubMed

    Lee, Byung-Cheol; Kim, Myung-Sunny; Pae, Munkyong; Yamamoto, Yasuhiko; Eberlé, Delphine; Shimada, Takeshi; Kamei, Nozomu; Park, Hee-Sook; Sasorith, Souphatta; Woo, Ju Rang; You, Jia; Mosher, William; Brady, Hugh J M; Shoelson, Steven E; Lee, Jongsoon

    2016-04-12

    Obesity-induced inflammation mediated by immune cells in adipose tissue appears to participate in the pathogenesis of insulin resistance. We show that natural killer (NK) cells in adipose tissue play an important role. High-fat diet (HFD) increases NK cell numbers and the production of proinflammatory cytokines, notably TNFα, in epididymal, but not subcutaneous, fat depots. When NK cells were depleted either with neutralizing antibodies or genetic ablation in E4bp4(+/-) mice, obesity-induced insulin resistance improved in parallel with decreases in both adipose tissue macrophage (ATM) numbers, and ATM and adipose tissue inflammation. Conversely, expansion of NK cells following IL-15 administration or reconstitution of NK cells into E4bp4(-/-) mice increased both ATM numbers and adipose tissue inflammation and exacerbated HFD-induced insulin resistance. These results indicate that adipose NK cells control ATMs as an upstream regulator potentially by producing proinflammatory mediators, including TNFα, and thereby contribute to the development of obesity-induced insulin resistance. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Erythropoietin (EPO) ameliorates obesity and glucose homeostasis by promoting thermogenesis and endocrine function of classical brown adipose tissue (BAT) in diet-induced obese mice

    PubMed Central

    Kodo, Kazuki; Sugimoto, Satoru; Mori, Jun; Itoh, Ikuyo; Fukuhara, Shota; Shigehara, Keiichi; Nishikawa, Taichiro; Kosaka, Kitaro; Hosoi, Hajime

    2017-01-01

    Erythropoietin (EPO), clinically used as a hematopoietic drug, has received much attention due to its nonhematopoietic effects. EPO reportedly has beneficial effects on obesity and diabetes mellitus. We investigated whether interscapular brown adipose tissue (iBAT: main part of classical BAT) could play a role in EPO’s anti-obesity and anti-diabetic effects in diet-induced obese mice. Four-week-old male C57BL/6J mice were fed a high-fat diet (HFD-Con), and half were additionally given an intraperitoneal injection of recombinant human EPO (200 IU/kg) (HFD-EPO) thrice a week for four weeks. At 8 weeks, EPO-injected mice showed significantly reduced body weight with reduced epididymal and subcutaneous white fat mass and unchanged caloric intake and locomotor activity. HOMA-IR (insulin resistance index) and glucose levels during intraperitoneal glucose tolerance test (IPGTT) were significantly lower in HFD-EPO mice than in HFD-Con mice. EPO-injected mice also showed increased oxygen consumption, indicative of metabolic rate, and skin temperature around iBAT tissue masses. EPO significantly upregulated the PRD1-BF1-RIZ1 homologous domain containing 16 (PRDM16), a transcriptional factor with a crucial role in brown adipocyte differentiation. EPO significantly increased phosphorylated signal transducer and activator of transcription 3 (STAT3), which is downstream of erythropoietin receptor (EpoR) and known to stabilize PRDM16. EPO’s suppression of myocyte enhancer factor 2c (Mef2c) and microRNA-133a (miR-133a) via β3-adrenergic receptor caused PRDM16 upregulation. EPO-mediated enhancement of EpoR/STAT3 and β-adrenergic receptor/Mef2c/miR-133 pathways dramatically increases total uncoupling protein 1 (UCP1), an essential enzyme for BAT thermogenesis. Furthermore, EPO activated BAT’s endocrine functions. EPO facilitated fibroblast growth factor 21 (FGF21) production and excretion in iBAT, associated with reduction of liver gluconeogenesis-related genes. Thus, EPO

  20. Erythropoietin (EPO) ameliorates obesity and glucose homeostasis by promoting thermogenesis and endocrine function of classical brown adipose tissue (BAT) in diet-induced obese mice.

    PubMed

    Kodo, Kazuki; Sugimoto, Satoru; Nakajima, Hisakazu; Mori, Jun; Itoh, Ikuyo; Fukuhara, Shota; Shigehara, Keiichi; Nishikawa, Taichiro; Kosaka, Kitaro; Hosoi, Hajime

    2017-01-01

    Erythropoietin (EPO), clinically used as a hematopoietic drug, has received much attention due to its nonhematopoietic effects. EPO reportedly has beneficial effects on obesity and diabetes mellitus. We investigated whether interscapular brown adipose tissue (iBAT: main part of classical BAT) could play a role in EPO's anti-obesity and anti-diabetic effects in diet-induced obese mice. Four-week-old male C57BL/6J mice were fed a high-fat diet (HFD-Con), and half were additionally given an intraperitoneal injection of recombinant human EPO (200 IU/kg) (HFD-EPO) thrice a week for four weeks. At 8 weeks, EPO-injected mice showed significantly reduced body weight with reduced epididymal and subcutaneous white fat mass and unchanged caloric intake and locomotor activity. HOMA-IR (insulin resistance index) and glucose levels during intraperitoneal glucose tolerance test (IPGTT) were significantly lower in HFD-EPO mice than in HFD-Con mice. EPO-injected mice also showed increased oxygen consumption, indicative of metabolic rate, and skin temperature around iBAT tissue masses. EPO significantly upregulated the PRD1-BF1-RIZ1 homologous domain containing 16 (PRDM16), a transcriptional factor with a crucial role in brown adipocyte differentiation. EPO significantly increased phosphorylated signal transducer and activator of transcription 3 (STAT3), which is downstream of erythropoietin receptor (EpoR) and known to stabilize PRDM16. EPO's suppression of myocyte enhancer factor 2c (Mef2c) and microRNA-133a (miR-133a) via β3-adrenergic receptor caused PRDM16 upregulation. EPO-mediated enhancement of EpoR/STAT3 and β-adrenergic receptor/Mef2c/miR-133 pathways dramatically increases total uncoupling protein 1 (UCP1), an essential enzyme for BAT thermogenesis. Furthermore, EPO activated BAT's endocrine functions. EPO facilitated fibroblast growth factor 21 (FGF21) production and excretion in iBAT, associated with reduction of liver gluconeogenesis-related genes. Thus, EPO

  1. Identification of the avian RBP7 gene as a new adipose-specific gene and RBP7 promoter-driven GFP expression in adipose tissue of transgenic quail.

    PubMed

    Ahn, Jinsoo; Shin, Sangsu; Suh, Yeunsu; Park, Ju Yeon; Hwang, Seongsoo; Lee, Kichoon

    2015-01-01

    The discovery of an increasing number of new adipose-specific genes has significantly contributed to our understanding of adipose tissue biology and the etiology of obesity and its related diseases. In the present study, comparison of gene expression profiles among various tissues was performed by analysis of chicken microarray data, leading to identification of RBP7 as a novel adipose-specific gene in chicken. Adipose-specific expression of RBP7 in the avian species was further confirmed at the protein and mRNA levels. Examination of the transcription factor binding sites within the chicken RBP7 promoter by Matinspector software revealed potential binding sites for adipogenic transcription factors. This led to the hypothesis that the RBP7 promoter can be utilized to overexpress a transgene in adipose tissue in order to further investigate the function of a transgene in adipose tissue. Several lines of transgenic quail containing a green fluorescent protein (GFP) gene under the control of the RBP7 promoter were generated using lentivirus-mediated gene transfer. The GFP expression in transgenic quail was specific to adipose tissue and increased after adipocyte differentiation. This expression pattern was consistent with endogenous RBP7 expression, suggesting the RBP7 promoter is sufficient to overexpress a gene of interest in adipose tissue at later developmental stages. These findings will lead to the establishment of a novel RBP7 promoter cassette which can be utilized for overexpressing genes of interest in adipose tissue in vivo to study the function of genes in adipose tissue development and lipid metabolism.

  2. Direct effects of leptin on brown and white adipose tissue.

    PubMed

    Siegrist-Kaiser, C A; Pauli, V; Juge-Aubry, C E; Boss, O; Pernin, A; Chin, W W; Cusin, I; Rohner-Jeanrenaud, F; Burger, A G; Zapf, J; Meier, C A

    1997-12-01

    Leptin is thought to exert its actions on energy homeostasis through the long form of the leptin receptor (OB-Rb), which is present in the hypothalamus and in certain peripheral organs, including adipose tissue. In this study, we examined whether leptin has direct effects on the function of brown and white adipose tissue (BAT and WAT, respectively) at the metabolic and molecular levels. The chronic peripheral intravenous administration of leptin in vivo for 4 d resulted in a 1.6-fold increase in the in vivo glucose utilization index of BAT, whereas no significant change was found after intracerebroventricular administration compared with pair-fed control rats, compatible with a direct effect of leptin on BAT. The effect of leptin on WAT fat pads from lean Zucker Fa/ fa rats was assessed ex vivo, where a 9- and 16-fold increase in the rate of lipolysis was observed after 2 h of exposure to 0.1 and 10 nM leptin, respectively. In contrast, no increase in lipolysis was observed in the fat pads from obese fa/fa rats, which harbor an inactivating mutation in the OB-Rb. At the level of gene expression, leptin treatment for 24 h increased malic enzyme and lipoprotein lipase RNA 1.8+/-0.17 and 1.9+/-0.14-fold, respectively, while aP2 mRNA levels were unaltered in primary cultures of brown adipocytes from lean Fa/fa rats. Importantly, however, no significant effect of leptin was observed on these genes in brown adipocytes from obese fa/fa animals. The presence of OB-Rb receptors in adipose tissue was substantiated by the detection of its transcripts by RT-PCR, and leptin treatment in vivo and in vitro activated the specific STATs implicated in the signaling pathway of the OB-Rb. Taken together, our data strongly suggest that leptin has direct effects on BAT and WAT, resulting in the activation of the Jak/STAT pathway and the increased expression of certain target genes, which may partially account for the observed increase in glucose utilization and lipolysis in leptin

  3. Direct effects of leptin on brown and white adipose tissue.

    PubMed Central

    Siegrist-Kaiser, C A; Pauli, V; Juge-Aubry, C E; Boss, O; Pernin, A; Chin, W W; Cusin, I; Rohner-Jeanrenaud, F; Burger, A G; Zapf, J; Meier, C A

    1997-01-01

    Leptin is thought to exert its actions on energy homeostasis through the long form of the leptin receptor (OB-Rb), which is present in the hypothalamus and in certain peripheral organs, including adipose tissue. In this study, we examined whether leptin has direct effects on the function of brown and white adipose tissue (BAT and WAT, respectively) at the metabolic and molecular levels. The chronic peripheral intravenous administration of leptin in vivo for 4 d resulted in a 1.6-fold increase in the in vivo glucose utilization index of BAT, whereas no significant change was found after intracerebroventricular administration compared with pair-fed control rats, compatible with a direct effect of leptin on BAT. The effect of leptin on WAT fat pads from lean Zucker Fa/ fa rats was assessed ex vivo, where a 9- and 16-fold increase in the rate of lipolysis was observed after 2 h of exposure to 0.1 and 10 nM leptin, respectively. In contrast, no increase in lipolysis was observed in the fat pads from obese fa/fa rats, which harbor an inactivating mutation in the OB-Rb. At the level of gene expression, leptin treatment for 24 h increased malic enzyme and lipoprotein lipase RNA 1.8+/-0.17 and 1.9+/-0.14-fold, respectively, while aP2 mRNA levels were unaltered in primary cultures of brown adipocytes from lean Fa/fa rats. Importantly, however, no significant effect of leptin was observed on these genes in brown adipocytes from obese fa/fa animals. The presence of OB-Rb receptors in adipose tissue was substantiated by the detection of its transcripts by RT-PCR, and leptin treatment in vivo and in vitro activated the specific STATs implicated in the signaling pathway of the OB-Rb. Taken together, our data strongly suggest that leptin has direct effects on BAT and WAT, resulting in the activation of the Jak/STAT pathway and the increased expression of certain target genes, which may partially account for the observed increase in glucose utilization and lipolysis in leptin

  4. Updated survey of the steroid-converting enzymes in human adipose tissues.

    PubMed

    Tchernof, André; Mansour, Mohamed Fouad; Pelletier, Mélissa; Boulet, Marie-Michèle; Nadeau, Mélanie; Luu-The, Van

    2015-03-01

    Over the past decade, adipose tissues have been increasingly known for their endocrine properties, that is, their ability to secrete a number of adipocytokines that may exert local and/or systemic effects. In addition, adipose tissues have long been recognized as significant sites for steroid hormone transformation and action. We hereby provide an updated survey of the many steroid-converting enzymes that may be detected in human adipose tissues, their activities and potential roles. In addition to the now well-established role of aromatase and 11β-hydroxysteroid dehydrogenase (HSD) type 1, many enzymes have been reported in adipocyte cell lines, isolated mature cells and/or preadipocytes. These include 11β-HSD type 2, 17β-HSDs, 3β-HSD, 5α-reductases, sulfatases and glucuronosyltransferases. Some of these enzymes are postulated to bear relevance for adipose tissue physiology and perhaps for the pathophysiology of obesity. This elaborate set of steroid-converting enzymes in the cell types of adipose tissue deserves further scientific attention. Our work on 20α-HSD (AKR1C1), 3α-HSD type 3 (AKR1C2) and 17β-HSD type 5 (AKR1C3) allowed us to clarify the relevance of these enzymes for some aspects of adipose tissue function. For example, down-regulation of AKR1C2 expression in preadipocytes seems to potentiate the inhibitory action of dihydrotestosterone on adipogenesis in this model. Many additional studies are warranted to assess the impact of intra-adipose steroid hormone conversions on adipose tissue functions and chronic conditions such as obesity, diabetes and cancer. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Ghrelin receptor regulates adipose tissue inflammation in aging

    PubMed Central

    Buras, Eric D.; Yu, Kaijiang; Wang, Ruitao; Smith, C. Wayne; Wu, Huaizhu; Sheikh-Hamad, David; Sun, Yuxiang

    2016-01-01

    Aging is commonly associated with low-grade adipose inflammation, which is closely linked to insulin resistance. Ghrelin is the only circulating orexigenic hormone which is known to increase obesity and insulin resistance. We previously reported that the expression of the ghrelin receptor, growth hormone secretagogue receptor (GHS-R), increases in adipose tissues during aging, and old Ghsr−/− mice exhibit a lean and insulin-sensitive phenotype. Macrophages are major mediators of adipose tissue inflammation, which consist of pro-inflammatory M1 and anti-inflammatory M2 subtypes. Here, we show that in aged mice, GHS-R ablation promotes macrophage phenotypical shift toward anti-inflammatory M2. Old Ghsr−/− mice have reduced macrophage infiltration, M1/M2 ratio, and pro-inflammatory cytokine expression in white and brown adipose tissues. We also found that peritoneal macrophages of old Ghsr−/− mice produce higher norepinephrine, which is in line with increased alternatively-activated M2 macrophages. Our data further reveal that GHS-R has cell-autonomous effects in macrophages, and GHS-R antagonist suppresses lipopolysaccharide (LPS)-induced inflammatory responses in macrophages. Collectively, our studies demonstrate that ghrelin signaling has an important role in macrophage polarization and adipose tissue inflammation during aging. GHS-R antagonists may serve as a novel and effective therapeutic option for age-associated adipose tissue inflammation and insulin resistance. PMID:26837433

  6. Ghrelin receptor regulates adipose tissue inflammation in aging.

    PubMed

    Lin, Ligen; Lee, Jong Han; Buras, Eric D; Yu, Kaijiang; Wang, Ruitao; Smith, C Wayne; Wu, Huaizhu; Sheikh-Hamad, David; Sun, Yuxiang

    2016-01-01

    Aging is commonly associated with low-grade adipose inflammation, which is closely linked to insulin resistance. Ghrelin is the only circulating orexigenic hormone which is known to increase obesity and insulin resistance. We previously reported that the expression of the ghrelin receptor, growth hormone secretagogue receptor (GHS-R), increases in adipose tissues during aging, and old Ghsr(-/-) mice exhibit a lean and insulin-sensitive phenotype. Macrophages are major mediators of adipose tissue inflammation, which consist of pro-inflammatory M1 and anti-inflammatory M2 subtypes. Here, we show that in aged mice, GHS-R ablation promotes macrophage phenotypical shift toward anti-inflammatory M2. Old Ghsrp(-/-) mice have reduced macrophage infiltration, M1/M2 ratio, and pro-inflammatory cytokine expression in white and brown adipose tissues. We also found that peritoneal macrophages of old Ghsrp(-/-) mice produce higher norepinephrine, which is in line with increased alternatively-activated M2 macrophages. Our data further reveal that GHS-R has cell-autonomous effects in macrophages, and GHS-R antagonist suppresses lipopolysaccharide (LPS)-induced inflammatory responses in macrophages. Collectively, our studies demonstrate that ghrelin signaling has an important role in macrophage polarization and adipose tissue inflammation during aging. GHS-R antagonists may serve as a novel and effective therapeutic option for age-associated adipose tissue inflammation and insulin resistance.

  7. Cold-Induced Changes in Gene Expression in Brown Adipose Tissue, White Adipose Tissue and Liver

    PubMed Central

    Shore, Andrew M.; Karamitri, Angeliki; Kemp, Paul; Speakman, John R.; Graham, Neil S.; Lomax, Michael A.

    2013-01-01

    Cold exposure imposes a metabolic challenge to mammals that is met by a coordinated response in different tissues to prevent hypothermia. This study reports a transcriptomic analysis in brown adipose tissue (BAT), white adipose (WAT) and liver of mice in response to 24 h cold exposure at 8°C. Expression of 1895 genes were significantly (P<0.05) up- or down-regulated more than two fold by cold exposure in all tissues but only 5 of these genes were shared by all three tissues, and only 19, 14 and 134 genes were common between WAT and BAT, WAT and liver, and BAT and liver, respectively. We confirmed using qRT-PCR, the increased expression of a number of characteristic BAT genes during cold exposure. In both BAT and the liver, the most common direction of change in gene expression was suppression (496 genes in BAT and 590 genes in liver). Gene ontology analysis revealed for the first time significant (P<0.05) down regulation in response to cold, of genes involved in oxidoreductase activity, lipid metabolic processes and protease inhibitor activity, in both BAT and liver, but not WAT. The results reveal an unexpected importance of down regulation of cytochrome P450 gene expression and apolipoprotein, in both BAT and liver, but not WAT, in response to cold exposure. Pathway analysis suggests a model in which down regulation of the nuclear transcription factors HNF4α and PPARα in both BAT and liver may orchestrate the down regulation of genes involved in lipoprotein and steroid metabolism as well as Phase I enzymes belonging to the cytochrome P450 group in response to cold stress in mice. We propose that the response to cold stress involves decreased gene expression in a range of cellular processes in order to maximise pathways involved in heat production. PMID:23894377

  8. Direct effects of sex steroid hormones on adipose tissues and obesity.

    PubMed

    Mayes, J S; Watson, G H

    2004-11-01

    Sex steroid hormones are involved in the metabolism, accumulation and distribution of adipose tissues. It is now known that oestrogen receptor, progesterone receptor and androgen receptor exist in adipose tissues, so their actions could be direct. Sex steroid hormones carry out their function in adipose tissues by both genomic and nongenomic mechanisms. In the genomic mechanism, the sex steroid hormone binds to its receptor and the steroid-receptor complex regulates the transcription of given genes. Leptin and lipoprotein lipase are two key proteins in adipose tissues that are regulated by transcriptional control with sex steroid hormones. In the nongenomic mechanism, the sex steroid hormone binds to its receptor in the plasma membrane, and second messengers are formed. This involves both the cAMP cascade and the phosphoinositide cascade. Activation of the cAMP cascade by sex steroid hormones would activate hormone-sensitive lipase leading to lipolysis in adipose tissues. In the phosphoinositide cascade, diacylglycerol and inositol 1,4,5-trisphosphate are formed as second messengers ultimately causing the activation of protein kinase C. Their activation appears to be involved in the control of preadipocyte proliferation and differentiation. In the presence of sex steroid hormones, a normal distribution of body fat exists, but with a decrease in sex steroid hormones, as occurs with ageing or gonadectomy, there is a tendency to increase central obesity, a major risk for cardiovascular disease, type 2 diabetes and certain cancers. Because sex steroid hormones regulate the amount and distribution of adipose tissues, they or adipose tissue-specific selective receptor modulators might be used to ameliorate obesity. In fact, hormone replacement therapy in postmenopausal women and testosterone replacement therapy in older men appear to reduce the degree of central obesity. However, these therapies have numerous side effects limiting their use, and selective receptor

  9. Controlled cellular energy conversion in brown adipose tissue thermogenesis

    NASA Technical Reports Server (NTRS)

    Horowitz, J. M.; Plant, R. E.

    1978-01-01

    Brown adipose tissue serves as a model system for nonshivering thermogenesis (NST) since a) it has as a primary physiological function the conversion of chemical energy to heat; and b) preliminary data from other tissues involved in NST (e.g., muscle) indicate that parallel mechanisms may be involved. Now that biochemical pathways have been proposed for brown fat thermogenesis, cellular models consistent with a thermodynamic representation can be formulated. Stated concisely, the thermogenic mechanism in a brown fat cell can be considered as an energy converter involving a sequence of cellular events controlled by signals over the autonomic nervous system. A thermodynamic description for NST is developed in terms of a nonisothermal system under steady-state conditions using network thermodynamics. Pathways simulated include mitochondrial ATP synthesis, a Na+/K+ membrane pump, and ionic diffusion through the adipocyte membrane.

  10. Controlled cellular energy conversion in brown adipose tissue thermogenesis

    NASA Technical Reports Server (NTRS)

    Horowitz, J. M.; Plant, R. E.

    1978-01-01

    Brown adipose tissue serves as a model system for nonshivering thermogenesis (NST) since a) it has as a primary physiological function the conversion of chemical energy to heat; and b) preliminary data from other tissues involved in NST (e.g., muscle) indicate that parallel mechanisms may be involved. Now that biochemical pathways have been proposed for brown fat thermogenesis, cellular models consistent with a thermodynamic representation can be formulated. Stated concisely, the thermogenic mechanism in a brown fat cell can be considered as an energy converter involving a sequence of cellular events controlled by signals over the autonomic nervous system. A thermodynamic description for NST is developed in terms of a nonisothermal system under steady-state conditions using network thermodynamics. Pathways simulated include mitochondrial ATP synthesis, a Na+/K+ membrane pump, and ionic diffusion through the adipocyte membrane.

  11. ENPP2 contributes to adipose tissue expansion and insulin resistance in diet-induced obesity.

    PubMed

    Nishimura, Satoshi; Nagasaki, Mika; Okudaira, Shinichi; Aoki, Junken; Ohmori, Tsukasa; Ohkawa, Ryunosuke; Nakamura, Kazuhiro; Igarashi, Koji; Yamashita, Hiroshi; Eto, Koji; Uno, Kansei; Hayashi, Naoto; Kadowaki, Takashi; Komuro, Issei; Yatomi, Yutaka; Nagai, Ryozo

    2014-12-01

    Body weight is tightly regulated by food intake and energy dissipation, and obesity is related to decreased energy expenditure (EE). Herein, we show that nucleotide pyrophosphatase/phosphodiesterase 2 (ENPP2, autotaxin) is an adipose-derived, secreted enzyme that controls adipose expansion, brown adipose tissue (BAT) function, and EE. In mice, Enpp2 was highly expressed in visceral white adipose tissue and BAT and is downregulated in hypertrophied adipocytes/adipose tissue. Enpp2(+/-) mice and adipocyte-specific Enpp2 knockout mice fed a high-fat diet showed smaller body weight gains and less insulin resistance than control mice fed the same diet. BAT was functionally more active and EE was increased in Enpp2-deficient mice. In humans, ENPP2 expression in subcutaneous fat and ENPP2 levels in serum were reduced in obese subjects. Taken together, our results establish ENPP2 as an adipose-derived, secreted enzyme that regulates adipose obesity and systemic metabolism. They also suggest ENPP2 could be a useful therapeutic target for the treatment of metabolic disease. © 2014 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  12. Human periprostatic adipose tissue promotes prostate cancer aggressiveness in vitro

    PubMed Central

    2012-01-01

    Background Obesity is associated with prostate cancer aggressiveness and mortality. The contribution of periprostatic adipose tissue, which is often infiltrated by malignant cells, to cancer progression is largely unknown. Thus, this study aimed to determine if periprostatic adipose tissue is linked with aggressive tumor biology in prostate cancer. Methods Supernatants of whole adipose tissue (explants) or stromal vascular fraction (SVF) from paired fat samples of periprostatic (PP) and pre-peritoneal visceral (VIS) anatomic origin from different donors were prepared and analyzed for matrix metalloproteinases (MMPs) 2 and 9 activity. The effects of those conditioned media (CM) on growth and migration of hormone-refractory (PC-3) and hormone-sensitive (LNCaP) prostate cancer cells were measured. Results We show here that PP adipose tissue of overweight men has higher MMP9 activity in comparison with normal subjects. The observed increased activities of both MMP2 and MMP9 in PP whole adipose tissue explants, likely reveal the contribution of adipocytes plus stromal-vascular fraction (SVF) as opposed to SVF alone. MMP2 activity was higher for PP when compared to VIS adipose tissue. When PC-3 cells were stimulated with CM from PP adipose tissue explants, increased proliferative and migratory capacities were observed, but not in the presence of SVF. Conversely, when LNCaP cells were stimulated with PP explants CM, we found enhanced motility despite the inhibition of proliferation, whereas CM derived from SVF increased both cell proliferation and motility. Explants culture and using adipose tissue of PP origin are most effective in promoting proliferation and migration of PC-3 cells, as respectively compared with SVF culture and using adipose tissue of VIS origin. In LNCaP cells, while explants CM cause increased migration compared to SVF, the use of PP adipose tissue to generate CM result in the increase of both cellular proliferation and migration. Conclusions Our

  13. Role of adipose tissue renin-angiotensin system in metabolic and inflammatory diseases associated with obesity.

    PubMed

    Yvan-Charvet, Laurent; Quignard-Boulangé, Annie

    2011-01-01

    Obesity is a leading cause of death worldwide because of its associated inflammatory disorders such as hypertension, cardiovascular and kidney diseases, dyslipidemia, glucose intolerance, and certain types of cancer. Adipose tissue expresses all components of the renin-angiotensin system necessary to generate angiotensin (Ang) peptides for local function. The angiotensin type 1 (AT1) and type 2 (AT2) receptors mediate the effect of Ang II and recent studies have shown that both receptors may modulate fat mass expansion through upregulation of adipose tissue lipogenesis (AT2) and downregulation of lipolysis (AT1). Thus, both receptors may have synergistic and additive effects to promote the storage of lipid in adipose tissue in response to the nutrient environment. The production of angiotensinogen (AGT) by adipose tissue in rodents also contributes to one third of the circulating AGT levels. Increased adipose tissue AGT production in the obese state may be responsible in part for the metabolic and inflammatory disorders associated with obesity. This supports the notion that besides the traditional role of Ang II produced by the liver in the control of blood pressure, Ang II produced by the adipose tissue may more accurately reflect the role of this hormone in the regulation of fat mass and associated disorders.

  14. Exercise Regulation of Marrow Adipose Tissue

    PubMed Central

    Pagnotti, Gabriel M.; Styner, Maya

    2016-01-01

    Despite association with low bone density and skeletal fractures, marrow adipose tissue (MAT) remains poorly understood. The marrow adipocyte originates from the mesenchymal stem cell (MSC) pool that also gives rise to osteoblasts, chondrocytes, and myocytes, among other cell types. To date, the presence of MAT has been attributed to preferential biasing of MSC into the adipocyte rather than osteoblast lineage, thus negatively impacting bone formation. Here, we focus on understanding the physiology of MAT in the setting of exercise, dietary interventions, and pharmacologic agents that alter fat metabolism. The beneficial effect of exercise on musculoskeletal strength is known: exercise induces bone formation, encourages growth of skeletally supportive tissues, inhibits bone resorption, and alters skeletal architecture through direct and indirect effects on a multiplicity of cells involved in skeletal adaptation. MAT is less well studied due to the lack of reproducible quantification techniques. In recent work, osmium-based 3D quantification shows a robust response of MAT to both dietary and exercise intervention in that MAT is elevated in response to high-fat diet and can be suppressed following daily exercise. Exercise-induced bone formation correlates with suppression of MAT, such that exercise effects might be due to either calorie expenditure from this depot or from mechanical biasing of MSC lineage away from fat and toward bone, or a combination thereof. Following treatment with the anti-diabetes drug rosiglitazone – a PPARγ-agonist known to increase MAT and fracture risk – mice demonstrate a fivefold higher femur MAT volume compared to the controls. In addition to preventing MAT accumulation in control mice, exercise intervention significantly lowers MAT accumulation in rosiglitazone-treated mice. Importantly, exercise induction of trabecular bone volume is unhindered by rosiglitazone. Thus, despite rosiglitazone augmentation of MAT, exercise

  15. Effect of functional sympathetic nervous system impairment of the liver and abdominal visceral adipose tissue on circulating triglyceride-rich lipoproteins.

    PubMed

    La Fountaine, Michael F; Cirnigliaro, Christopher M; Kirshblum, Steven C; McKenna, Cristin; Bauman, William A

    2017-01-01

    Interruption of sympathetic innervation to the liver and visceral adipose tissue (VAT) in animal models has been reported to reduce VAT lipolysis and hepatic secretion of very low density lipoprotein (VLDL) and concentrations of triglyceride-rich lipoprotein particles. Whether functional impairment of sympathetic nervous system (SNS) innervation to tissues of the abdominal cavity reduce circulating concentrations of triglyceride (TG) and VLDL particles (VLDL-P) was tested in men with spinal cord injury (SCI). One hundred-three non-ambulatory men with SCI [55 subjects with neurologic injury at or proximal to the 4th thoracic vertebrae (↑T4); 48 subjects with SCI at or distal to the 5th thoracic vertebrae (↓T5)] and 53 able-bodied (AB) subjects were studied. Fasting blood samples were obtained for determination of TG, VLDL-P concentration by NMR spectroscopy, serum glucose by autoanalyzer, and plasma insulin by radioimmunoassay. VAT volume was determined by dual energy x-ray absorptiometry imaging with calculation by a validated proprietary software package. Significant group main effects for TG and VLDL-P were present; post-hoc tests revealed that serum TG concentrations were significantly higher in ↓T5 group compared to AB and ↑T4 groups [150±9 vs. 101±8 (p<0.01) and 112±8 mg/dl (p<0.05), respectively]. VLDL-P concentration was significantly elevated in ↓T5 group compared to AB and ↑T4 groups [74±4 vs. 58±4 (p<0.05) and 55±4 μmol/l (p<0.05)]. VAT volume was significantly higher in both SCI groups than in the AB group, and HOMA-IR was higher and approached significance in the SCI groups compared to the AB group. A linear relationship between triglyceride rich lipoproteins (i.e., TG or Large VLDL-P) and VAT volume or HOMA-IR was significant only in the ↓T5 group. Despite a similar VAT volume and insulin resistance in both SCI groups, the ↓T5 group had significantly higher serum TG and VLDL-P values than that observed in the ↑T4 and the AB

  16. Effect of functional sympathetic nervous system impairment of the liver and abdominal visceral adipose tissue on circulating triglyceride-rich lipoproteins

    PubMed Central

    Cirnigliaro, Christopher M.; Kirshblum, Steven C.; McKenna, Cristin

    2017-01-01

    Background Interruption of sympathetic innervation to the liver and visceral adipose tissue (VAT) in animal models has been reported to reduce VAT lipolysis and hepatic secretion of very low density lipoprotein (VLDL) and concentrations of triglyceride-rich lipoprotein particles. Whether functional impairment of sympathetic nervous system (SNS) innervation to tissues of the abdominal cavity reduce circulating concentrations of triglyceride (TG) and VLDL particles (VLDL-P) was tested in men with spinal cord injury (SCI). Methods One hundred-three non-ambulatory men with SCI [55 subjects with neurologic injury at or proximal to the 4th thoracic vertebrae (↑T4); 48 subjects with SCI at or distal to the 5th thoracic vertebrae (↓T5)] and 53 able-bodied (AB) subjects were studied. Fasting blood samples were obtained for determination of TG, VLDL-P concentration by NMR spectroscopy, serum glucose by autoanalyzer, and plasma insulin by radioimmunoassay. VAT volume was determined by dual energy x-ray absorptiometry imaging with calculation by a validated proprietary software package. Results Significant group main effects for TG and VLDL-P were present; post-hoc tests revealed that serum TG concentrations were significantly higher in ↓T5 group compared to AB and ↑T4 groups [150±9 vs. 101±8 (p<0.01) and 112±8 mg/dl (p<0.05), respectively]. VLDL-P concentration was significantly elevated in ↓T5 group compared to AB and ↑T4 groups [74±4 vs. 58±4 (p<0.05) and 55±4 μmol/l (p<0.05)]. VAT volume was significantly higher in both SCI groups than in the AB group, and HOMA-IR was higher and approached significance in the SCI groups compared to the AB group. A linear relationship between triglyceride rich lipoproteins (i.e., TG or Large VLDL-P) and VAT volume or HOMA-IR was significant only in the ↓T5 group. Conclusions Despite a similar VAT volume and insulin resistance in both SCI groups, the ↓T5 group had significantly higher serum TG and VLDL-P values than

  17. Disruption of inducible 6-phosphofructo-2-kinase ameliorates diet-induced adiposity but exacerbates systemic insulin resistance and adipose tissue inflammatory response.

    PubMed

    Huo, Yuqing; Guo, Xin; Li, Honggui; Wang, Huan; Zhang, Weiyu; Wang, Ying; Zhou, Huaijun; Gao, Zhanguo; Telang, Sucheta; Chesney, Jason; Chen, Y Eugene; Ye, Jianping; Chapkin, Robert S; Wu, Chaodong

    2010-02-05

    Adiposity is commonly associated with adipose tissue dysfunction and many overnutrition-related metabolic diseases including type 2 diabetes. Much attention has been paid to reducing adiposity as a way to improve adipose tissue function and systemic insulin sensitivity. PFKFB3/iPFK2 is a master regulator of adipocyte nutrient metabolism. Using PFKFB3(+/-) mice, the present study investigated the role of PFKFB3/iPFK2 in regulating diet-induced adiposity and systemic insulin resistance. On a high-fat diet (HFD), PFKFB3(+/-) mice gained much less body weight than did wild-type littermates. This was attributed to a smaller increase in adiposity in PFKFB3(+/-) mice than in wild-type controls. However, HFD-induced systemic insulin resistance was more severe in PFKFB3(+/-) mice than in wild-type littermates. Compared with wild-type littermates, PFKFB3(+/-) mice exhibited increased severity of HFD-induced adipose tissue dysfunction, as evidenced by increased adipose tissue lipolysis, inappropriate adipokine expression, and decreased insulin signaling, as well as increased levels of proinflammatory cytokines in both isolated adipose tissue macrophages and adipocytes. In an in vitro system, knockdown of PFKFB3/iPFK2 in 3T3-L1 adipocytes caused a decrease in the rate of glucose incorporation into lipid but an increase in the production of reactive oxygen species. Furthermore, knockdown of PFKFB3/iPFK2 in 3T3-L1 adipocytes inappropriately altered the expression of adipokines, decreased insulin signaling, increased the phosphorylation states of JNK and NFkappaB p65, and enhanced the production of proinflammatory cytokines. Together, these data suggest that PFKFB3/iPFK2, although contributing to adiposity, protects against diet-induced insulin resistance and adipose tissue inflammatory response.

  18. Growth hormone and adipose tissue: beyond the adipocyte

    PubMed Central

    Berryman, Darlene E.; List, Edward O.; Sackmann-Sala, Lucila; Lubbers, Ellen; Munn, Rachel; Kopchick, John J.

    2011-01-01

    The last two decades have seen resurgence in the interest in, and research on, adipose tissue. In part, the increased interest stems from an alarming increase in obesity rates worldwide. However, an understanding that this once simple tissue is significantly more intricate and interactive than previously realized has fostered additional attention. While few would argue that growth hormone (GH) radically alters adipose tissue, a better appreciation of the newer complexities requires that GH's influence on this tissue be reexamined. Therefore, the objective of this review is to describe the more recent understanding of adipose tissue and how GH may influence and contribute to these newer complexities with special focus on the available data from mice with altered GH action. PMID:21470887

  19. Mitochondrial respiration in subcutaneous and visceral adipose tissue from patients with morbid obesity.

    PubMed

    Kraunsøe, Regitze; Boushel, Robert; Hansen, Christina Neigaard; Schjerling, Peter; Qvortrup, Klaus; Støckel, Mikael; Mikines, Kári J; Dela, Flemming

    2010-06-15

    Adipose tissue exerts important endocrine and metabolic functions in health and disease. Yet the bioenergetics of this tissue is not characterized in humans and possible regional differences are not elucidated. Using high resolution respirometry, mitochondrial respiration was quantified in human abdominal subcutaneous and intra-abdominal visceral (omentum majus) adipose tissue from biopsies obtained in 20 obese patients undergoing bariatric surgery. Mitochondrial DNA (mtDNA) and genomic DNA (gDNA) were determined by the PCR technique for estimation of mitochondrial density. Adipose tissue samples were permeabilized and respirometric measurements were performed in duplicate at 37 degrees C. Substrates (glutamate (G) + malate (M) + octanoyl carnitine (O) + succinate (S)) were added sequentially to provide electrons to complex I + II. ADP ((D)) for state 3 respiration was added after GM. Uncoupled respiration was measured after addition of FCCP. Visceral fat contained more mitochondria per milligram of tissue than subcutaneous fat, but the cells were smaller. Robust, stable oxygen fluxes were found in both tissues, and coupled state 3 (GMOS(D)) and uncoupled respiration were significantly (P < 0.05) higher in visceral (0.95 +/- 0.05 and 1.15 +/- 0.06 pmol O(2) s(1) mg(1), respectively) compared with subcutaneous (0.76 +/- 0.04 and 0.98 +/- 0.05 pmol O(2) s(1) mg(1), respectively) adipose tissue. Expressed per mtDNA, visceral adipose tissue had significantly (P < 0.05) lower mitochondrial respiration. Substrate control ratios were higher and uncoupling control ratio lower (P < 0.05) in visceral compared with subcutaneous adipose tissue. We conclude that visceral fat is bioenergetically more active and more sensitive to mitochondrial substrate supply than subcutaneous fat. Oxidative phosphorylation has a higher relative activity in visceral compared with subcutaneous adipose tissue.

  20. White adipose tissue resilience to insulin deprivation and replacement.

    PubMed

    Hadji, Lilas; Berger, Emmanuelle; Soula, Hédi; Vidal, Hubert; Géloën, Alain

    2014-01-01

    Adipocyte size and body fat distribution are strongly linked to the metabolic complications of obesity. The aim of the present study was to test the plasticity of white adipose tissue in response to insulin deprivation and replacement. We have characterized the changes of adipose cell size repartition and gene expressions in type 1 diabetes Sprague-Dawley rats and type 1 diabetic supplemented with insulin. Using streptozotocin (STZ)-induced diabetes, we induced rapid changes in rat adipose tissue weights to study the changes in the distribution of adipose cell sizes in retroperitoneal (rWAT), epididymal (eWAT) and subcutaneous adipose tissues (scWAT). Adipose tissue weights of type 1 diabetic rats were then rapidly restored by insulin supplementation. Cell size distributions were analyzed using multisizer IV (Beckman Coulter). Cell size changes were correlated to transcriptional regulation of genes coding for proteins involved in lipid and glucose metabolisms and adipocytokines. The initial body weight of the rats was 465±5.2 g. Insulin privation was stopped when rats lost 100 g which induced reductions in fat mass of 68% for rWAT, 42% for eWAT and 59% for scWAT corresponding to decreased mode cell diameters by 31.1%, 20%, 25.3%, respectively. The most affected size distribution by insulin deprivation was observed in rWAT. The bimodal distribution of adipose cell sizes disappeared in response to insulin deprivation in rWAT and scWAT. The most important observation is that cell size distribution returned close to control values in response to insulin treatment. mRNAs coding for adiponectin, leptin and apelin were more stimulated in scWAT compared to other depots in diabetic plus insulin group. Fat depots have specific responses to insulin deprivation and supplementation. The results show that insulin is a major determinant of bimodal cell repartition in adipose tissues.

  1. White Adipose Tissue Resilience to Insulin Deprivation and Replacement

    PubMed Central

    Hadji, Lilas; Berger, Emmanuelle; Soula, Hédi; Vidal, Hubert; Géloën, Alain

    2014-01-01

    Introduction Adipocyte size and body fat distribution are strongly linked to the metabolic complications of obesity. The aim of the present study was to test the plasticity of white adipose tissue in response to insulin deprivation and replacement. We have characterized the changes of adipose cell size repartition and gene expressions in type 1 diabetes Sprague-Dawley rats and type 1 diabetic supplemented with insulin. Methods Using streptozotocin (STZ)-induced diabetes, we induced rapid changes in rat adipose tissue weights to study the changes in the distribution of adipose cell sizes in retroperitoneal (rWAT), epididymal (eWAT) and subcutaneous adipose tissues (scWAT). Adipose tissue weights of type 1 diabetic rats were then rapidly restored by insulin supplementation. Cell size distributions were analyzed using multisizer IV (Beckman Coulter). Cell size changes were correlated to transcriptional regulation of genes coding for proteins involved in lipid and glucose metabolisms and adipocytokines. Results The initial body weight of the rats was 465±5.2 g. Insulin privation was stopped when rats lost 100 g which induced reductions in fat mass of 68% for rWAT, 42% for eWAT and 59% for scWAT corresponding to decreased mode cell diameters by 31.1%, 20%, 25.3%, respectively. The most affected size distribution by insulin deprivation was observed in rWAT. The bimodal distribution of adipose cell sizes disappeared in response to insulin deprivation in rWAT and scWAT. The most important observation is that cell size distribution returned close to control values in response to insulin treatment. mRNAs coding for adiponectin, leptin and apelin were more stimulated in scWAT compared to other depots in diabetic plus insulin group. Conclusion Fat depots have specific responses to insulin deprivation and supplementation. The results show that insulin is a major determinant of bimodal cell repartition in adipose tissues. PMID:25170835

  2. Impaired Adipose Tissue Expandability and Lipogenic Capacities as Ones of the Main Causes of Metabolic Disorders

    PubMed Central

    Tinahones, Francisco José

    2015-01-01

    Obesity is considered a major health problem. However, mechanisms involved and its comorbidities are not elucidated. Recent theories concerning the causes of obesity have focused on a limit to the functional capacity of adipose tissue, comparing it with other vital organs. This assumption has been the central point of interest in our laboratory. We proposed that the failure of adipose tissue is initiated by the difficulty of this tissue to increase its cellularity due to excess in fat contribution, owing to genetic or environmental factors. Nevertheless, why the adipose tissue reduces its capacity to make new adipocytes via mesenchymal cells of the stroma has not yet been elucidated. Thus, we suggest that this tissue ceases fulfilling its main function, the storage of excess fat, thereby affecting some of the key factors involved in lipogenesis, some of which are reviewed in this paper (PPARγ, ROR1, FASN, SCD1, Rab18, BrCa1, ZAG, and FABP4). On the other hand, mechanisms involved in adipose tissue expandability are also impaired, predominating hypertrophy via an increase in apoptosis and a decrease in adipogenesis and angiogenesis. However, adipose tissue failure is only part of this great orchestra, only a chapter of this nightmare. PMID:25922847

  3. Gene expression profiling in adipose tissue from growing broiler chickens

    PubMed Central

    Hausman, Gary J; Barb, C Rick; Fairchild, Brian D; Gamble, John; Lee-Rutherford, Laura

    2014-01-01

    In this study, total RNA was collected from abdominal adipose tissue samples obtained from ten broiler chickens at 3, 4, 5, and 6 weeks of age and prepared for gene microarray analysis with Affymetrix GeneChip Chicken Genome Arrays (Affymetrix) and quantitative real-time PCR analysis. Studies of global gene expression in chicken adipose tissue were initiated since such studies in many animal species show that adipose tissue expresses and secretes many factors that can influence growth and physiology. Microarray results indicated 333 differentially expressed adipose tissue genes between 3 and 6 wk, 265 differentially expressed genes between 4 and 6 wk and 42 differentially expressed genes between 3 and 4 wk. Enrichment scores of Gene Ontology Biological Process categories indicated strong age upregulation of genes involved in the immune system response. In addition to microarray analysis, quantitative real-time PCR analysis was used to confirm the influence of age on the expression of adipose tissue CC chemokine ligands (CCL), toll-like receptor (TLR)-2, lipopolysaccharide-induced TNF factor (LITAF), chemokine (C-C motif) receptor 8 (CCR8), and several other genes. Between 3 and 6 wk of age CCL5, CCL1, and CCR8 expression increased (P = 0.0001) with age. Furthermore, TLR2, CCL19, and LITAF expression increased between 4 and 6 wk of age (P = 0.001). This is the first demonstration of age related changes in CCL, LITAF, and TLR2 gene expression in chicken adipose tissue. Future studies are needed to elucidate the role of these adipose tissue genes in growth and the immune system. PMID:26317054

  4. Preventing diet-induced obesity in mice by adipose tissue transformation and angiogenesis using targeted nanoparticles

    PubMed Central

    Xue, Yuan; Xu, Xiaoyang; Zhang, Xue-Qing; Farokhzad, Omid C.; Langer, Robert

    2016-01-01

    The incidence of obesity, which is recognized by the American Medical Association as a disease, has nearly doubled since 1980, and obesity-related comorbidities have become a major threat to human health. Given that adipose tissue expansion and transformation require active growth of new blood vasculature, angiogenesis offers a potential target for the treatment of obesity-associated disorders. Here we construct two peptide-functionalized nanoparticle (NP) platforms to deliver either Peroxisome Proliferator-Activated Receptor gamma (PPARgamma) activator rosiglitazone (Rosi) or prostaglandin E2 analog (16,16-dimethyl PGE2) to adipose tissue vasculature. These NPs were engineered through self-assembly of a biodegradable triblock polymer composed of end-to-end linkages between poly(lactic-coglycolic acid)-b-poly(ethylene glycol) (PLGA-b-PEG) and an endothelial-targeted peptide. In this system, released Rosi promotes both transformation of white adipose tissue (WAT) into brown-like adipose tissue and angiogenesis, which facilitates the homing of targeted NPs to adipose angiogenic vessels, thereby amplifying their delivery. We show that i.v. administration of these NPs can target WAT vasculature, stimulate the angiogenesis that is required for the transformation of adipose tissue, and transform WAT into brown-like adipose tissue, by the up-regulation of angiogenesis and brown adipose tissue markers. In a diet-induced obese mouse model, these angiogenesis-targeted NPs have inhibited body weight gain and modulated several serological markers including cholesterol, triglyceride, and insulin, compared with the control group. These findings suggest that angiogenesis-targeting moieties with angiogenic stimulator-loaded NPs could be incorporated into effective therapeutic regimens for clinical treatment of obesity and other metabolic diseases. PMID:27140638

  5. Adipocyte Pseudohypoxia Suppresses Lipolysis and Facilitates Benign Adipose Tissue Expansion

    PubMed Central

    Morton, Nicholas M.; Moreno Navarrete, José Maria; West, Christopher C.; Stewart, Kenneth J.; Fernández-Real, José Manuel; Schofield, Christopher J.; Seckl, Jonathan R.; Ratcliffe, Peter J.

    2015-01-01

    Prolyl hydroxylase enzymes (PHDs) sense cellular oxygen upstream of hypoxia-inducible factor (HIF) signaling, leading to HIF degradation in normoxic conditions. In this study, we demonstrate that adipose PHD2 inhibition plays a key role in the suppression of adipocyte lipolysis. Adipose Phd2 gene ablation in mice enhanced adiposity, with a parallel increase in adipose vascularization associated with reduced circulating nonesterified fatty acid levels and normal glucose homeostasis. Phd2 gene–depleted adipocytes exhibited lower basal lipolysis in normoxia and reduced β-adrenergic–stimulated lipolysis in both normoxia and hypoxia. A selective PHD inhibitor suppressed lipolysis in murine and human adipocytes in vitro and in vivo in mice. PHD2 genetic ablation and pharmacological inhibition attenuated protein levels of the key lipolytic effectors hormone-sensitive lipase and adipose triglyceride lipase (ATGL), suggesting a link between adipocyte oxygen sensing and fatty acid release. PHD2 mRNA levels correlated positively with mRNA levels of AB-hydrolase domain containing-5, an activator of ATGL, and negatively with mRNA levels of lipid droplet proteins, perilipin, and TIP47 in human subcutaneous adipose tissue. Therapeutic pseudohypoxia caused by PHD2 inhibition in adipocytes blunts lipolysis and promotes benign adipose tissue expansion and may have therapeutic applications in obesity or lipodystrophy. PMID:25377876

  6. A metabolomic study of adipose tissue in mice with a disruption of the circadian system

    PubMed Central

    Castro, C.; Briggs, W.; Paschos, G. K.; FitzGerald, G. A.; Griffin, J. L.

    2016-01-01

    Adipose tissue functions in terms of energy homeostasis as a rheostat for blood triglyceride, regulating its concentration, in response to external stimuli. In addition it acts as a barometer to inform the central nervous system of energy levels which can vary dramatically between meals and according to energy demand. Here a metabolomic approach, combining both Mass Spectrometry and Nuclear Magnetic Resonance spectroscopy, was used to analyse both white and brown adipose tissue in mice with adipocyte-specific deletion of Arntl (also known as Bmal1), a gene encoding a core molecular clock component. The results are consistent with a peripheral circadian clock playing a central role in metabolic regulation of both brown and white adipose tissue in rodents and show that Arntl induced global changes in both tissues which were distinct for the two types. In particular, anterior subcutaneous white adipose tissue (ASWAT) tissue was effected by a reduction in the degree of unsaturation of fatty acids, while brown adipose tissue (BAT) changes were associated with a reduction in chain length. In addition the aqueous fraction of metabolites in BAT were profoundly affected by Arntl disruption, consistent with the dynamic role of this tissue in maintaining body temperature across the day/night cycle and an upregulation in fatty acid oxidation and citric acid cycle activity to generate heat during the day when rats are inactive (increases in 3-hydroxybutyrate and glutamate), and increased synthesis and storage of lipids during the night when rats feed more (increased concentrations of glycerol, choline and glycerophosphocholine). PMID:25907923

  7. Brown adipose tissue as an anti-obesity tissue in humans.

    PubMed

    Chechi, K; Nedergaard, J; Richard, D

    2014-02-01

    During the 11th Stock Conference held in Montreal, Quebec, Canada, world-leading experts came together to present and discuss recent developments made in the field of brown adipose tissue biology. Owing to the vast capacity of brown adipose tissue for burning food energy in the process of thermogenesis, and due to demonstrations of its presence in adult humans, there is tremendous interest in targeting brown adipose tissue as an anti-obesity tissue in humans. However, the future of such therapeutic approaches relies on our understanding of the origin, development, recruitment, activation and regulation of brown adipose tissue in humans. As reviewed here, the 11th Stock Conference was organized around these themes to discuss the recent progress made in each aspect, to identify gaps in our current understanding and to further provide a common groundwork that could support collaborative efforts aimed at a future therapy for obesity, based on brown adipose tissue thermogenesis.

  8. Adipose Tissue Residing Progenitors (Adipocyte Lineage Progenitors and Adipose Derived Stem Cells (ADSC)

    PubMed Central

    Berry, Ryan; Rodeheffer, Matthew S.; Rosen, Clifford J.; Horowitz, Mark C.

    2015-01-01

    The formation of brown, white and beige adipocytes have been a subject of intense scientific interest in recent years due to the growing obesity epidemic in the United States and around the world. This interest has led to the identification and characterization of specific tissue resident progenitor cells that give rise to each adipocyte population in vivo. However, much still remains to be discovered about each progenitor population in terms of their “niche” within each tissue and how they are regulated at the cellular and molecular level during healthy and diseased states. While our knowledge of brown, white and beige adipose tissue is rapidly increasing, little is still known about marrow adipose tissue and its progenitor despite recent studies demonstrating possible roles for marrow adipose tissue in regulating the hematopoietic space and systemic metabolism at large. This chapter focuses on our current knowledge of brown, white, beige and marrow adipose tissue with a specific focus on the formation of each tissue from tissue resident progenitor cells. PMID:26526875

  9. Brown adipose tissue in humans: therapeutic potential to combat obesity.

    PubMed

    Carey, Andrew L; Kingwell, Bronwyn A

    2013-10-01

    Harnessing the considerable capacity of brown adipose tissue (BAT) to consume energy was first proposed as a potential target to control obesity nearly 40years ago. The plausibility of this approach was, however, questioned due to the prevailing view that BAT was either not present or not functional in adult humans. Recent definitive identification of functional BAT in adult humans as well as a number of important advances in the understanding of BAT biology has reignited interest in BAT as an anti-obesity target. Proof-of-concept evidence demonstrating drug-induced BAT activation provides an important foundation for development of targeted pharmacological approaches with clinical application. This review considers evidence from both human and relevant animal studies to determine whether harnessing BAT for the treatment of obesity via pharmacological intervention is a realistic goal. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Traveling from the hypothalamus to the adipose tissue: The thermogenic pathway.

    PubMed

    Contreras, Cristina; Nogueiras, Rubén; Diéguez, Carlos; Rahmouni, Kamal; López, Miguel

    2017-08-01

    Brown adipose tissue (BAT) is a specialized tissue critical for non-shivering thermogenesis producing heat through mitochondrial uncoupling; whereas white adipose tissue (WAT) is responsible of energy storage in the form of triglycerides. Another type of fat has been described, the beige adipose tissue; this tissue emerges in existing WAT depots but with thermogenic ability, a phenomenon known as browning. Several peripheral signals relaying information about energy status act in the brain, particularly the hypothalamus, to regulate thermogenesis in BAT and browning of WAT. Different hypothalamic areas have the capacity to regulate the thermogenic process in brown and beige adipocytes through the sympathetic nervous system (SNS). This review discusses important concepts and discoveries about the central control of thermogenesis as a trip that starts in the hypothalamus, and taking the sympathetic roads to reach brown and beige fat to modulate thermogenic functions. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  11. Analysis of type II diabetes mellitus adipose-derived stem cells for tissue engineering applications

    PubMed Central

    Minteer, Danielle Marie; Young, Matthew T; Lin, Yen-Chih; Over, Patrick J; Rubin, J Peter; Gerlach, Jorg C

    2015-01-01

    To address the functionality of diabetic adipose-derived stem cells in tissue engineering applications, adipose-derived stem cells isolated from patients with and without type II diabetes mellitus were cultured in bioreactor culture systems. The adipose-derived stem cells were differentiated into adipocytes and maintained as functional adipocytes. The bioreactor system utilizes a hollow fiber–based technology for three-dimensional perfusion of tissues in vitro, creating a model in which long-term culture of adipocytes is feasible, and providing a potential tool useful for drug discovery. Daily metabolic activity of the adipose-derived stem cells was analyzed within the medium recirculating throughout the bioreactor system. At experiment termination, tissues were extracted from bioreactors for immunohistological analyses in addition to gene and protein expression. Type II diabetic adipose-derived stem cells did not exhibit significantly different glucose consumption compared to adipose-derived stem cells from patients without type II diabetes (p > 0.05, N = 3). Expression of mature adipocyte genes was not significantly different between diabetic/non-diabetic groups (p > 0.05, N = 3). Protein expression of adipose tissue grown within all bioreactors was verified by Western blotting.The results from this small-scale study reveal adipose-derived stem cells from patients with type II diabetes when removed from diabetic environments behave metabolically similar to the same cells of non-diabetic patients when cultured in a three-dimensional perfusion bioreactor, suggesting that glucose transport across the adipocyte cell membrane, the hindrance of which being characteristic of type II diabetes, is dependent on environment. The presented observation describes a tissue-engineered tool for long-term cell culture and, following future adjustments to the culture environment and increased sample sizes, potentially for anti-diabetic drug testing. PMID:26090087

  12. Analysis of type II diabetes mellitus adipose-derived stem cells for tissue engineering applications.

    PubMed

    Minteer, Danielle Marie; Young, Matthew T; Lin, Yen-Chih; Over, Patrick J; Rubin, J Peter; Gerlach, Jorg C; Marra, Kacey G

    2015-01-01

    To address the functionality of diabetic adipose-derived stem cells in tissue engineering applications, adipose-derived stem cells isolated from patients with and without type II diabetes mellitus were cultured in bioreactor culture systems. The adipose-derived stem cells were differentiated into adipocytes and maintained as functional adipocytes. The bioreactor system utilizes a hollow fiber-based technology for three-dimensional perfusion of tissues in vitro, creating a model in which long-term culture of adipocytes is feasible, and providing a potential tool useful for drug discovery. Daily metabolic activity of the adipose-derived stem cells was analyzed within the medium recirculating throughout the bioreactor system. At experiment termination, tissues were extracted from bioreactors for immunohistological analyses in addition to gene and protein expression. Type II diabetic adipose-derived stem cells did not exhibit significantly different glucose consumption compared to adipose-derived stem cells from patients without type II diabetes (p > 0.05, N = 3). Expression of mature adipocyte genes was not significantly different between diabetic/non-diabetic groups (p > 0.05, N = 3). Protein expression of adipose tissue grown within all bioreactors was verified by Western blotting.The results from this small-scale study reveal adipose-derived stem cells from patients with type II diabetes when removed from diabetic environments behave metabolically similar to the same cells of non-diabetic patients when cultured in a three-dimensional perfusion bioreactor, suggesting that glucose transport across the adipocyte cell membrane, the hindrance of which being characteristic of type II diabetes, is dependent on environment. The presented observation describes a tissue-engineered tool for long-term cell culture and, following future adjustments to the culture environment and increased sample sizes, potentially for anti-diabetic drug testing.

  13. 17β-Estradiol suppresses visceral adipogenesis and activates brown adipose tissue-specific gene expression.

    PubMed

    Al-Qahtani, Saad Misfer; Bryzgalova, Galyna; Valladolid-Acebes, Ismael; Korach-André, Marion; Dahlman-Wright, Karin; Efendić, Suad; Berggren, Per-Olof; Portwood, Neil

    2017-01-01

    Both functional ovaries and estrogen replacement therapy (ERT) reduce the risk of type 2 diabetes (T2D). Understanding the mechanisms underlying the antidiabetic effects of 17β-estradiol (E2) may permit the development of a molecular targeting strategy for the treatment of metabolic disease. This study examines how the promotion of insulin sensitivity and weight loss by E2 treatment in high-fat-diet (HFD)-fed mice involve several anti-adipogenic processes in the visceral adipose tissue. Magnetic resonance imaging (MRI) revealed specific reductions in visceral adipose tissue volume in HFD+E2 mice, compared with HFD mice. This loss of adiposity was associated with diminished visceral adipocyte size and reductions in expression of lipogenic genes, adipokines and of the nuclear receptor nr2c2/tr4. Meanwhile, expression levels of adipose triglyceride lipase/pnpla2 and leptin receptor were increased. As mRNA levels of stat3, a transcription factor involved in brown adipose tissue differentiation, were also increased in visceral adipose, the expression of other brown adipose-specific markers was assessed. Both expression and immunohistochemical staining of ucp-1 were increased, and mRNA levels of dio-2, and of adrβ3, a regulator of ucp-1 expression during the thermogenic response, were increased. Furthermore, expression of cpt-1b, a brown adipose-specific gene involved in fatty acid utilization, was also increased. Methylation studies demonstrated that the methylation status of both dio-2 and adrβ3 was significantly reduced. These results show that improved glycemic control and weight loss due to E2 involve anti-adipogenic mechanisms which include suppressed lipogenesis and augmented fatty acid utilization, and in addition, the activation of brown adipose tissue-specific gene expression in association with E2-dependent epigenetic modifications in these genes.

  14. Factors affecting adipose tissue development in chickens: A review.

    PubMed

    Wang, Guoqing; Kim, Woo Kyun; Cline, Mark A; Gilbert, Elizabeth R

    2017-10-01

    The intense genetic selection for rapid growth in broilers has resulted in an increase in voluntary feed intake and growth rate, accompanied by increased fat deposition in adipose tissue depots throughout the body. Adipose tissue expansion is a result of the formation of adipocytes (several processes collectively referred to as adipogenesis) and cellular accumulation of triacylglycerols inside lipid droplets. In mammals, different anatomical depots are metabolically distinct. The molecular and cellular mechanisms underlying adipose tissue development have been characterized in mammalian models, whereas information in avian species is scarce. The purpose of this review is to describe factors regulating adipogenesis in chickens, with an emphasis on dietary factors and the broiler. Results from many studies have demonstrated effects of dietary nutrient composition on adipose tissue development and lipid metabolism. Transcription factors, such as peroxisome proliferator-activated receptor γ, CCAAT/enhancer-binding proteins α and β, and sterol regulatory element binding proteins orchestrate a series of cellular events that lead to an increase in activity of fatty acid transport proteins and enzymes that are responsible for triacylglycerol synthesis. Understanding the mechanisms underlying adipose tissue development may provide a practical strategy to affect body composition of the commercial broiler while providing insights on diets that maximize conversion into muscle rather than fat and affect depot-dependent deposition of lipids. Because of the propensity to overeat and become obese, the broiler chicken also represents an attractive biomedical model for eating disorders and obesity in humans. © 2017 Poultry Science Association Inc.

  15. Acute Testosterone Deficiency Alters Adipose Tissue Fatty Acid Storage.

    PubMed

    Santosa, Sylvia; Bush, Nikki C; Jensen, Michael D

    2017-08-01

    Although the long-term effects of testosterone on adipose tissue lipid metabolism in men have been defined, the short-term regulation of these effects is not well understood. We examined the effects of acute testosterone withdrawal on subcutaneous abdominal and femoral adipose tissue fatty acid (FA) storage and cellular mechanisms. This was a prospective, randomized trial. Mayo Clinic Clinical Research Unit. Thirty-two male volunteers ages 18 to 50 participated in these studies. Volunteers were randomized to receive (1) no treatment (control), (2) injections (7.5 mg) of Lupron®, or (3) Lupron and testosterone (L+T) replacement for 49 days, resulting in 4 weeks of sex steroid suppression in the Lupron group. We measured body composition, fat cell size, adipose tissue meal FA and direct free FA storage, lipoprotein lipase (LPL), acyl coenzyme A synthetase (ACS), diacylglycerol acyltransferase activities, and CD36 content. Compared with control and L+T groups, acute testosterone deficiency resulted in greater femoral adipose tissue meal FA storage rates, fasting and fed LPL activity, and ACS activity. These results suggest that in men, testosterone plays a tonic role in restraining FA storage in femoral adipose tissue via suppression of LPL and ACS activities. FA storage mechanisms in men appear sensitive to short-term changes in testosterone concentrations.

  16. Cellular changes during cold acclimatation in adipose tissues.

    PubMed

    Cousin, B; Bascands-Viguerie, N; Kassis, N; Nibbelink, M; Ambid, L; Casteilla, L; Pénicaud, L

    1996-05-01

    Cold exposure is a well-known physiological stimulus that activates the sympathetic nervous system and induces brown adipose tissue (BAT) hyperplasia. The effects of cold exposure or cold acclimatation have been extensively studied in interscapular BAT (IBAT). However, it has been recently shown that studied adipocytes are present in adipose deposits considered as white fat such as periovarian (PO) fat pad. We have investigated the kinetic of brown precursor recruitment in adipose tissues using DNA measurement and specific marker expression. In IBAT, cold exposure induces proliferation of precursor cells and differentiation into preadipocytes characterized by the expression of A2COL6, a marker specific to early steps of the differentiation process. A chronic stimulation of the tissue is necessary to observe the full effect. In PO fat pad, no proliferation can be detected, whereas differentiation of brown preadipocytes and maybe phenotypic conversion of white adipocytes seems to be promoted. In conclusion, these data demonstrated that 1) the same stimulus (cold exposure) does not induce the same response in terms of preadipocyte proliferation and differentiation in periovarian and brown adipose tissues, although both contain brown adipocytes, and 2) preadipocyte recruitment in adipose tissues after cold exposure depends on the predominant type of fat cells.

  17. A Novel Role for Subcutaneous Adipose Tissue in Exercise-Induced Improvements in Glucose Homeostasis

    PubMed Central

    Stanford, Kristin I.; Middelbeek, Roeland J.W.; Townsend, Kristy L.; Lee, Min-Young; Takahashi, Hirokazu; So, Kawai; Hitchcox, Kristen M.; Markan, Kathleen R.; Hellbach, Katharina; Hirshman, Michael F.; Tseng, Yu-Hua

    2015-01-01

    Exercise training improves whole-body glucose homeostasis through effects largely attributed to adaptations in skeletal muscle; however, training also affects other tissues, including adipose tissue. To determine whether exercise-induced adaptations to adipose tissue contribute to training-induced improvements in glucose homeostasis, subcutaneous white adipose tissue (scWAT) from exercise-trained or sedentary donor mice was transplanted into the visceral cavity of sedentary recipients. Remarkably, 9 days post-transplantation, mice receiving scWAT from exercise-trained mice had improved glucose tolerance and enhanced insulin sensitivity compared with mice transplanted with scWAT from sedentary or sham-treated mice. Mice transplanted with scWAT from exercise-trained mice had increased insulin-stimulated glucose uptake in tibialis anterior and soleus muscles and brown adipose tissue, suggesting that the transplanted scWAT exerted endocrine effects. Furthermore, the deleterious effects of high-fat feeding on glucose tolerance and insulin sensitivity were completely reversed if high-fat–fed recipient mice were transplanted with scWAT from exercise-trained mice. In additional experiments, voluntary exercise training by wheel running for only 11 days resulted in profound changes in scWAT, including the increased expression of ∼1,550 genes involved in numerous cellular functions including metabolism. Exercise training causes adaptations to scWAT that elicit metabolic improvements in other tissues, demonstrating a previously unrecognized role for adipose tissue in the beneficial effects of exercise on systemic glucose homeostasis. PMID:25605808

  18. NPY antagonism reduces adiposity and attenuates age-related imbalance of adipose tissue metabolism.

    PubMed

    Park, Seongjoon; Fujishita, Chika; Komatsu, Toshimitsu; Kim, Sang Eun; Chiba, Takuya; Mori, Ryoichi; Shimokawa, Isao

    2014-12-01

    An orexigenic hormone, neuropeptide Y (NPY), plays a role not only in the hypothalamic regulation of appetite, but also in the peripheral regulation of lipid metabolism. However, the intracellular mechanisms triggered by NPY to regulate lipid metabolism are poorly understood. Here we report that NPY deficiency reduces white adipose tissue (WAT) mass and ameliorates the age-related imbalance of adipose tissue metabolism in mice. Gene expression involved in adipogenesis/lipogenesis was found to decrease, whereas proteins involved in lipolysis increased in gonadal WAT (gWAT) of NPY-knockout mice. These changes were associated with an activated SIRT1- and PPARγ-mediated pathway. Moreover, the age-related decrease of de novo lipogenesis in gWAT and thermogenesis in inguinal WAT was inhibited by NPY deficiency. Further analysis using 3T3-L1 cells showed that NPY inhibited lipolysis through the Y1 receptor and enhanced lipogenesis following a reduction in cAMP response element-binding protein (CREB) and SIRT1 protein expression. Therefore, NPY appears to act as a key regulator of adipose tissue metabolism via the CREB-SIRT1 signaling pathway. Taken together, NPY deficiency reduces adiposity and ameliorates the age-related imbalance of adipose tissue metabolism, suggesting that antagonism of NPY may be a promising target for drug development to prevent age-related metabolic diseases. © FASEB.

  19. 11-Beta hydroxysteroid dehydrogenase type 2 expression in white adipose tissue is strongly correlated with adiposity.

    PubMed

    Milagro, Fermin I; Campión, Javier; Martínez, J Alfredo

    2007-04-01

    Glucocorticoid action within the cells is regulated by the levels of glucocorticoid receptor (GR) expression and two enzymes, 11-beta hydroxysteroid dehydrogenase type 1 (11betaHSD1), which converts inactive to active glucocorticoids, and 11-beta hydroxysteroid dehydrogenase type 2 (11betaHSD2), which regulates the access of active glucocorticoids to the receptor by converting cortisol/corticosterone to the glucocorticoid-inactive form cortisone/dehydrocorticosterone. Male Wistar rats developed obesity by being fed a high-fat diet for 56 days, and GR, 11betaHSD1 and 11betaHSD2 gene expression were compared with control-diet fed animals. Gene expression analysis of 11betaHSD1, 11betaHSD2 and GR were performed by RT-PCR in subcutaneous and retroperitoneal adipose tissue. High-fat fed animals overexpressed 11betaHSD2 in subcutaneous but not in retroperitoneal fat. Interestingly, mRNA levels strongly correlated in both tissues with different parameters related to obesity, such as body weight, adiposity and insulin resistance, suggesting that this gene is a reliable marker of adiposity in this rat model of obesity. Thus, 11betaHSD2 is expressed in adipose tissue by both adipocytes and stromal-vascular cells, which suggests that this enzyme may play an important role in preventing fat accumulation in adipose tissue.

  20. Perivascular adipose tissue alleviates inflammatory factors and stenosis in diabetic blood vessels.

    PubMed

    Li, Tianjia; Liu, Xinnong; Ni, Leng; Wang, Zhanqi; Wang, Wenda; Shi, Tao; Liu, Xiu; Liu, Changwei

    2016-11-11

    Adipose tissue can modulate disease processes in a depot-specific manner. However, the functional properties of perivascular adipocytes, and their influence on the pathophysiology of blood vessel walls, remain to be determined. In this study, we aimed to investigate whether perivascular adipose tissue could have an ameliorative effect on blood vessels damaged in diabetes. Using in vitro coculture, and in vivo transplantation model simulating diabetic angioplasty-induced injury, we showed that perivascular adipose tissue has an important function in protecting blood vessels from high glucose impairment. Levels of inflammatory cytokines, including intercellular cell adhesion molecule-1 and osteopontin, were markedly reduced, whereas that of endothelial nitric-oxide synthase was markedly elevated in vascular walls. These depot-specific differences in blood vessels exposed to high levels of glucose were demonstrable both in vivo, with transplanted adipose tissues, and in vitro, when vascular endothelial cells were cocultured with adipocytes. In addition, intimal hyperplasia was also decreased by transplanted perivascular adipose tissue after balloon injury combined with hyperglycemia. We conclude that perivascular adipocytes can reduce inflammation in blood vessels and promote the normal function of endothelium, which could afford a new therapeutic strategy in vascular walls damaged by diabetes. Copyright © 2016. Published by Elsevier Inc.

  1. Liver-adipose tissue crosstalk: A key player in the pathogenesis of glucolipid metabolic disease.

    PubMed

    Ye, De-Wei; Rong, Xiang-Lu; Xu, Ai-Min; Guo, Jiao

    2017-06-01

    Glucolipid metabolic disease (GLMD), a complex of interrelated disorders in glucose and lipid metabolism, has become one of the leading chronic diseases causing public and clinical problem worldwide. As the metabolism of lipid and glucose is a highly coordinated process under both physiological and diseased conditions, the impairment in the signals corresponding to the metabolism of either lipid or glucose represents the common mechanism underlying the pathogenesis of GLMD. The liver and adipose tissue are the major metabolic organs responsible for energy utilization and storage, respectively. This review article aims to summarize the current advances in the investigation of the functional roles and the underling mechanisms of the interplay between the liver and adipose tissue in the modulation of GLMD development. Fibroblast growth factor 21 (FGF21) and adiponectin represent the two major hormones secreted from the liver and adipose tissues, respectively. FGF21 exerts pleiotropic effects on regulating glucose and lipid homeostasis majorly through inducing the expression and secretion of adiponectin. Therefore, FGF21-adiponectin axis functions as the key mediator for the crosstalk between the liver and adipose tissue to exert the beneficial effects on the maintenance of the homeostasis of energy consumption. The liver- and adipose tissue-derived factors with pleiotropic effects on regulating of lipid and glucose metabolism function as the key mediator for the crosstalk between these two highly active metabolic organs, thereby coordinating the initiation and development of GLMD.

  2. Theoretical model of ruminant adipose tissue metabolism in relation to the whole animal.

    PubMed

    Baldwin, R L; Yang, Y T; Crist, K; Grichting, G

    1976-09-01

    Based on theoretical considerations and experimental data, estimates of contributions of adipose tissue to energy expenditures in a lactating cow and a growing steer were developed. The estimates indicate that adipose energy expenditures range between 5 and 10% of total animal heat production dependent on productive function and diet. These energy expenditures can be partitioned among maintenance (3%), lipogenesis (1-5%) and lipolysis and triglyceride resynthesis (less thatn 1.0%). Specific sites at which acute and chronic effectors can act to produce changes in adipose function, and changes in adipose function produced by diet and during pregnancy, lactation and aging were discussed with emphasis being placed on the need for additional, definitive studies of specific interactions among pregnancy, diet, age, lactation and growth in producing ruminants.

  3. Fenretinide mediated retinoic acid receptor signalling and inhibition of ceramide biosynthesis regulates adipogenesis, lipid accumulation, mitochondrial function and nutrient stress signalling in adipocytes and adipose tissue.

    PubMed

    Mcilroy, George D; Tammireddy, Seshu R; Maskrey, Benjamin H; Grant, Louise; Doherty, Mary K; Watson, David G; Delibegović, Mirela; Whitfield, Phillip D; Mody, Nimesh

    2016-01-15

    Fenretinide (FEN) is a synthetic retinoid that inhibits obesity and insulin resistance in high-fat diet (HFD)-fed mice and completely prevents 3T3-L1 pre-adipocyte differentiation. The aim of this study was to determine the mechanism(s) of FEN action in 3T3-L1 adipocytes and in mice. We used the 3T3-L1 model of adipogenesis, fully differentiated 3T3-L1 adipocytes and adipose tissue from HFD-induced obese mice to investigate the mechanisms of FEN action. We measured expression of adipogenic and retinoid genes by qPCR and activation of nutrient-signalling pathways by western blotting. Global lipid and metabolite analysis was performed and specific ceramide lipid species measured by liquid chromatography-mass spectrometry. We provide direct evidence that FEN inhibits 3T3-L1 adipogenesis via RA-receptor (RAR)-dependent signaling. However, RARα antagonism did not prevent FEN-induced decreases in lipid levels in mature 3T3-L1 adipocytes, suggesting an RAR-independent mechanism. Lipidomics analysis revealed that FEN increased dihydroceramide lipid species 5- to 16-fold in adipocytes, indicating an inhibition of the final step of ceramide biosynthesis. A similar blockade in adipose tissue from FEN-treated obese mice was associated with a complete normalisation of impaired mitochondrial β-oxidation and tricarboxylic acid cycle flux. The FEN catabolite, 4-oxo-N-(4-hydroxyphenyl)retinamide (4-OXO), also decreased lipid accumulation without affecting adipogenesis. FEN and 4-OXO (but not RA) treatment additionally led to the activation of p38-MAPK, peIF2α and autophagy markers in adipocytes. Overall our data reveals FEN utilises both RAR-dependent and -independent pathways to regulate adipocyte biology, both of which may be required for FEN to prevent obesity and insulin resistance in vivo. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Fenretinide mediated retinoic acid receptor signalling and inhibition of ceramide biosynthesis regulates adipogenesis, lipid accumulation, mitochondrial function and nutrient stress signalling in adipocytes and adipose tissue

    PubMed Central

    Mcilroy, George D.; Tammireddy, Seshu R.; Maskrey, Benjamin H.; Grant, Louise; Doherty, Mary K.; Watson, David G.; Delibegović, Mirela; Whitfield, Phillip D.; Mody, Nimesh

    2016-01-01

    Fenretinide (FEN) is a synthetic retinoid that inhibits obesity and insulin resistance in high-fat diet (HFD)-fed mice and completely prevents 3T3-L1 pre-adipocyte differentiation. The aim of this study was to determine the mechanism(s) of FEN action in 3T3-L1 adipocytes and in mice. We used the 3T3-L1 model of adipogenesis, fully differentiated 3T3-L1 adipocytes and adipose tissue from HFD-induced obese mice to investigate the mechanisms of FEN action. We measured expression of adipogenic and retinoid genes by qPCR and activation of nutrient-signalling pathways by western blotting. Global lipid and metabolite analysis was performed and specific ceramide lipid species measured by liquid chromatography-mass spectrometry. We provide direct evidence that FEN inhibits 3T3-L1 adipogenesis via RA-receptor (RAR)-dependent signaling. However, RARα antagonism did not prevent FEN-induced decreases in lipid levels in mature 3T3-L1 adipocytes, suggesting an RAR-independent mechanism. Lipidomics analysis revealed that FEN increased dihydroceramide lipid species 5- to 16-fold in adipocytes, indicating an inhibition of the final step of ceramide biosynthesis. A similar blockade in adipose tissue from FEN-treated obese mice was associated with a complete normalisation of impaired mitochondrial β-oxidation and tricarboxylic acid cycle flux. The FEN catabolite, 4-oxo-N-(4-hydroxyphenyl)retinamide (4-OXO), also decreased lipid accumulation without affecting adipogenesis. FEN and 4-OXO (but not RA) treatment additionally led to the activation of p38-MAPK, peIF2α and autophagy markers in adipocytes. Overall our data reveals FEN utilises both RAR-dependent and -independent pathways to regulate adipocyte biology, both of which may be required for FEN to prevent obesity and insulin resistance in vivo. PMID:26592777

  5. Obesity accelerates T cell senescence in murine visceral adipose tissue.

    PubMed

    Shirakawa, Kohsuke; Yan, Xiaoxiang; Shinmura, Ken; Endo, Jin; Kataoka, Masaharu; Katsumata, Yoshinori; Yamamoto, Tsunehisa; Anzai, Atsushi; Isobe, Sarasa; Yoshida, Naohiro; Itoh, Hiroshi; Manabe, Ichiro; Sekai, Miho; Hamazaki, Yoko; Fukuda, Keiichi; Minato, Nagahiro; Sano, Motoaki

    2016-12-01

    Chronic inflammation in visceral adipose tissue (VAT) precipitates the development of cardiometabolic disorders. Although changes in T cell function associated with visceral obesity are thought to affect chronic VAT inflammation, the specific features of these changes remain elusive. Here, we have determined that a high-fat diet (HFD) caused a preferential increase and accumulation of CD44hiCD62LloCD4+ T cells that constitutively express PD-1 and CD153 in a B cell-dependent manner in VAT. These cells possessed characteristics of cellular senescence and showed a strong activation of Spp1 (encoding osteopontin [OPN]) in VAT. Upon T cell receptor stimulation, these T cells also produced large amounts of OPN in a PD-1-resistant manner in vitro. The features of CD153+PD-1+CD44hiCD4+ T cells were highly reminiscent of senescence-associated CD4+ T cells that normally increase with age. Adoptive transfer of CD153+PD-1+CD44hiCD4+ T cells from HFD-fed WT, but not Spp1-deficient, mice into the VAT of lean mice fed a normal diet recapitulated the essential features of VAT inflammation and insulin resistance. Our results demonstrate that a distinct CD153+PD-1+CD44hiCD4+ T cell population that accumulates in the VAT of HFD-fed obese mice causes VAT inflammation by producing large amounts of OPN. This finding suggests a link between visceral adiposity and immune aging.

  6. Adipocyte-specific deletion of mTOR inhibits adipose tissue development and causes insulin resistance in mice.

    PubMed

    Shan, Tizhong; Zhang, Pengpeng; Jiang, Qinyang; Xiong, Yan; Wang, Yizhen; Kuang, Shihuan

    2016-09-01

    The in vivo role of mechanistic target of rapamycin (mTOR) in the development and function of adipose tissue, especially brown adipose tissue (BAT), is not well understood. Here, we aimed to assess the effect of mTOR (also known as Mtor) knockout on adipose tissues and systemic energy metabolism. We generated adipocyte-specific mTOR-knockout mice (Adipoq-mTOR) by crossing adiponectin-Cre (Adipoq-Cre) mice with mTOR (flox/flox) mice. The mice were then subjected to morphological, physiological (indirect calorimetry, glucose and insulin tolerance tests) and gene expression analyses to determine the role of mTOR in adipose tissues. We provide in vivo evidence that mTOR is essential for adipose tissue development and growth. Deletion of mTOR decreased the mass of both BAT and white adipose tissues (WAT) and induced browning of WAT. In addition, ablation of mTOR in adipose tissues caused insulin resistance and fatty liver in the Adipoq-mTOR mice. Furthermore, mTOR was required for adipocyte differentiation in vivo and activation of PPARγ ameliorated the differentiation deficiency of the mTOR-null adipocytes. Our findings demonstrate that mTOR is a critical regulator of adipogenesis and systemic energy metabolism. Our study provides key insights into the role of mTOR in adipose tissues; such knowledge may facilitate the development of novel strategies with which to treat obesity and related metabolic diseases.

  7. [Adaptation of adipose tissue to weight-reduction energy-restricted diet in obese individuals].

    PubMed

    Štich, Vladimír

    2016-01-01

    Obesity is associated with a number of metabolic disorders that lead to the development of type 2 diabetes, hyperlipidemia and ultimately cardiovascular diseases. An important role in the pathogenesis of metabolic disorders accompanying obesity is probably played by the alterations of adipose tissue characteristics: metabolic, endocrine and immune functions. The key component of obesity treatment, the weight-reduction energy-restricted diet, leads not only to the reduction of weight (specifically fat mass), but also to correction of obesity accompanying metabolic disorders. The mechanisms which mediate the metabolic effect of the weight-reduction energy-restricted diet, are unclear. It can be assumed that the weight-reduction diet "corrects" the impaired functions of the obese individuals adipose tissue and, subsequently, of the resulting metabolic disorders. The following text presents an overview of the changes of morphological and functional characteristics of adipose tissue that are induced by weight-reduction energy-restricted diets in obese individuals: the energy-restricted diet and the associated weight reduction cause a change in the size and differentiation of adipocytes, a change of metabolic functions, primarily of the regulation of adipose tissue lipolysis and lipogenesis, change in the regulation of endocrine functions and, finally, they lead to the change in the immune function indicators, i.e. adipose tissue infiltration with immune cells and secretion of a spectrum of cytokines. The knowledge about the mechanisms of favourable metabolic effects of energy-restricted diets may lead to an advancement in non-pharmacological procedures of therapy for obesity and its complications, and, in the longer, term to the development of new therapeutic pharmacological procedures.Key words: energy-restricted diet - obesity - weight reduction - adipose tissue.

  8. Epicardial adipose tissue in endocrine and metabolic diseases.

    PubMed

    Iacobellis, Gianluca

    2014-05-01

    Epicardial adipose tissue has recently emerged as new risk factor and active player in metabolic and cardiovascular diseases. Albeit its physiological and pathological roles are not completely understood, a body of evidence indicates that epicardial adipose tissue is a fat depot with peculiar and unique features. Epicardial fat is able to synthesize, produce, and secrete bioactive molecules which are then transported into the adjacent myocardium through vasocrine and/or paracrine pathways. Based on these evidences, epicardial adipose tissue can be considered an endocrine organ. Epicardial fat is also thought to provide direct heating to the myocardium and protect the heart during unfavorable hemodynamic conditions, such as ischemia or hypoxia. Epicardial fat has been suggested to play an independent role in the development and progression of obesity- and diabetes-related cardiac abnormalities. Clinically, the thickness of epicardial fat can be easily and accurately measured. Epicardial fat thickness can serve as marker of visceral adiposity and visceral fat changes during weight loss interventions and treatments with drugs targeting the fat. The potential of modulating the epicardial fat with targeted pharmacological agents can open new avenues in the pharmacotherapy of endocrine and metabolic diseases. This review article will provide Endocrine's reader with a focus on epicardial adipose tissue in endocrinology. Novel, established, but also speculative findings on epicardial fat will be discussed from the unexplored perspective of both clinical and basic Endocrinologist.

  9. Recent Advances in Proteomic Studies of Adipose Tissues and Adipocytes

    PubMed Central

    Kim, Eun Young; Kim, Won Kon; Oh, Kyoung-Jin; Han, Baek Soo; Lee, Sang Chul; Bae, Kwang-Hee

    2015-01-01

    Obesity is a chronic disease that is associated with significantly increased levels of risk of a number of metabolic disorders. Despite these enhanced health risks, the worldwide prevalence of obesity has increased dramatically over the past few decades. Obesity is caused by the accumulation of an abnormal amount of body fat in adipose tissue, which is composed mostly of adipocytes. Thus, a deeper understanding of the regulation mechanism of adipose tissue and/or adipocytes can provide a clue for overcoming obesity-related metabolic diseases. In this review, we describe recent advances in the study of adipose tissue and/or adipocytes, focusing on proteomic approaches. In addition, we suggest future research directions for proteomic studies which may lead to novel treatments of obesity and obesity-related diseases. PMID:25734986

  10. Developmental programming of fetal skeletal muscle and adipose tissue development.

    PubMed

    Yan, Xu; Zhu, Mei-Jun; Dodson, Michael V; Du, Min

    2013-01-01

    All important developmental milestones are accomplished during the fetal stage, and nutrient fluctuation during this stage produces lasting effects on offspring health, so called fetal programming or developmental programming. The fetal stage is critical for skeletal muscle development, as well as adipose and connective tissue development. Maternal under-nutrition at this stage affects the proliferation of myogenic precursor cells and reduces the number of muscle fibers formed. Maternal over-nutrition results in impaired myogenesis and elevated adipogenesis. Because myocytes, adipocytes and fibrocytes are all derived from mesenchymal stem cells, molecular events which regulate the commitment of stem cells to different lineages directly impact fetal muscle and adipose tissue development. Recent studies indicate that microRNA is intensively involved in myogenic and adipogenic differentiation from mesenchymal stem cells, and epigenetic changes such as DNA methylation are expected to alter cell lineage commitment during fetal muscle and adipose tissue development.

  11. The effect of hypokinesia on lipid metabolism in adipose tissue

    NASA Astrophysics Data System (ADS)

    Macho, Ladislav; Kvetn̆anský, Richard; Ficková, Mária

    The increase of nonesterified fatty acid (NEFA) concentration in plasma was observed in rats subjected to hypokinesia for 1-60 days. In the period of recovery (7 and 21 days after 60 days immobilization) the content of NEFA returned to control values. The increase of fatty acid release from adipose tissue was observed in hypokinetic rats, however the stimulation of lipolysis by norepinephrine was lower in rats exposed to hypokinesis. The decrease of the binding capacity and a diminished number of beta-adrenergic receptors were found in animals after hypokinesia. The augmentation of the incorporation of glucose into lipids and the marked increase in the stimulation of lipogenesis by insulin were found in adipose tissue of rats subjected to long-term hypokinesia. These results showed an important effect of hypokinesia on lipid mobilization, on lipogenesis and on the processes of hormone regulation in adipose tissue.

  12. Vitamin D modulates adipose tissue biology: possible consequences for obesity?

    PubMed

    Landrier, Jean-François; Karkeni, Esma; Marcotorchino, Julie; Bonnet, Lauriane; Tourniaire, Franck

    2016-02-01

    Cross-sectional studies depict an inverse relationship between vitamin D (VD) status reflected by plasma 25-hydroxy-vitamin D and obesity. Furthermore, recent studies in vitro and in animal models tend to demonstrate an impact of VD and VD receptor on adipose tissue and adipocyte biology, pointing to at least a part-causal role of VD insufficiency in obesity and associated physiopathological disorders such as adipose tissue inflammation and subsequent insulin resistance. However, clinical and genetic studies are far less convincing, with highly contrasted results ruling out solid conclusions for the moment. Nevertheless, prospective studies provide interesting data supporting the hypothesis of a preventive role of VD in onset of obesity. The aim of this review is to summarise the available data on relationships between VD, adipose tissue/adipocyte physiology, and obesity in order to reveal the next key points that need to be addressed before we can gain deeper insight into the controversial VD-obesity relationship.

  13. The effects of adipose tissue and adipocytokines in human pregnancy.

    PubMed

    Valsamakis, G; Kumar, S; Creatsas, G; Mastorakos, G

    2010-09-01

    During pregnancy, important changes take place in maternal metabolism because of the growing fetus and placental formation. The increase in insulin resistance during pregnancy is paralleled by the progressive increase of maternal adipose tissue deposition. This review examines the topography of fat mass deposition during pregnancy in relation to factors such as parity and maternal age that might affect this deposition. We also examine adipose tissue markers, such as pregravid weight and weight gain during pregnancy, and their effect on fetal growth and pregnancy outcomes. In addition, this review studies the possible effects of cytokines that are produced by adipose tissue and the placenta on maternal metabolism and its complications. Finally, we also consider the possible role of maternal adipocytokines and fetal adipocytokines on fetal growth. © 2010 New York Academy of Sciences.

  14. Assessment of feline abdominal adipose tissue using computed tomography.

    PubMed

    Lee, Hyeyeon; Kim, Mieun; Choi, Mihyun; Lee, Namsoon; Chang, Jinhwa; Yoon, Junghee; Choi, Mincheol

    2010-12-01

    Obesity is a common nutritional disorder in cats and it increases the risk factors for various diseases. The aim of this study is to suggest a method for the evaluation of feline obesity using computed tomography. The attenuation range from -156 to -106 was determined as the range of feline abdominal adipose tissue. With this range, total (TAT), visceral (VAT) and subcutaneous (SAT) adipose tissues were measured. The best correlation between the adipose tissue in cross-sectional image and entire abdomen volume was obtained at the L3 and L5 levels. The mean VAT/SAT ratio was 1.18±0.32, which was much higher than in humans. The cats with an overweight body condition had a significantly lower VAT/SAT ratio than cats with an ideal body condition. This technique may contribute to both the clinical diagnosis and the experimental study of feline obesity.

  15. Resistant starch improves insulin resistance and reduces adipose tissue weight and CD11c expression in rat OLETF adipose tissue.

    PubMed

    Harazaki, Tomomi; Inoue, Seiya; Imai, Chihiro; Mochizuki, Kazuki; Goda, Toshinao

    2014-05-01

    CD11s/CD18 dimers induce monocyte/macrophage infiltration into many tissues, including adipose tissues. In particular, it was reported that β2-integrin CD11c-positive macrophages in adipose tissues are closely associated with the development of insulin resistance. The aim of this study was to determine whether intake of resistant starch (RS) reduces macrophage accumulation in adipose tissues and inhibits the development of insulin resistance at an early stage in Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Twenty-two-wk-old male OLETF rats were fed a control diet (55% α-corn starch) or an RS diet (55% RS) for 5 wk. An oral glucose tolerance test was performed after 4 wk of feeding; tissues (mesenteric and epididymal adipose tissues, and liver) and tail vein blood were collected after 5 wk of feeding the test diets. Feeding the RS diet to OLETF rats for 5 wk improved insulin resistance, reduced the mesenteric adipose tissue weight, and enhanced the number of small adipocytes. CD68 expression, a macrophage infiltration marker, was not changed by the RS diet, whereas the gene expression levels of integrins such as CD11c, CD11d, and CD18, but not CD11a, and CD11b, were significantly reduced. CD11c protein expression was reduced by the RS diet. These findings suggest that part of the mechanism for the improved insulin resistance by the RS diet involves a reduction of CD11c expression in adipose tissues. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Activation of brown adipose tissue mitochondrial GDP binding sites

    SciTech Connect

    Swick, A.G.

    1987-01-01

    The primary function of brown adipose tissue (BAT) is heat production. This ability is attributed to the existence of a unique inner mitochondrial membrane protein termed the uncoupling protein or thermogenin. This protein is permeable to H+ and thus allows respiration (and therefore thermogenesis) to proceed at a rapid rate, independent of ADP phosphorylation. Proton conductance can be inhibited by the binding of purine nucleotides to the uncoupling protein. The binding of (/sup 3/H)-GDP to BAT mitochondria is frequently used as a measure of BAT thermogenic activity. Rats fed a diet that was low but adequate in protein exhibited a decrease in feed efficiency. In addition, BAT thermogenesis was activated as indicated by an elevation in the level of GDP binding to BAT mitochondria. This phenomena occurred in older rats and persisted over time.

  17. Brain insulin controls adipose tissue lipolysis and lipogenesis.

    PubMed

    Scherer, Thomas; O'Hare, James; Diggs-Andrews, Kelly; Schweiger, Martina; Cheng, Bob; Lindtner, Claudia; Zielinski, Elizabeth; Vempati, Prashant; Su, Kai; Dighe, Shveta; Milsom, Thomas; Puchowicz, Michelle; Scheja, Ludger; Zechner, Rudolf; Fisher, Simon J; Previs, Stephen F; Buettner, Christoph

    2011-02-02

    White adipose tissue (WAT) dysfunction plays a key role in the pathogenesis of type 2 diabetes (DM2). Unrestrained WAT lipolysis results in increased fatty acid release, leading to insulin resistance and lipotoxicity, while impaired de novo lipogenesis in WAT decreases the synthesis of insulin-sensitizing fatty acid species like palmitoleate. Here, we show that insulin infused into the mediobasal hypothalamus (MBH) of Sprague-Dawley rats increases WAT lipogenic protein expression, inactivates hormone-sensitive lipase (Hsl), and suppresses lipolysis. Conversely, mice that lack the neuronal insulin receptor exhibit unrestrained lipolysis and decreased de novo lipogenesis in WAT. Thus, brain and, in particular, hypothalamic insulin action play a pivotal role in WAT functionality. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Imaging of Brown Adipose Tissue: State of the Art

    PubMed Central

    Sampath, Srihari C.; Sampath, Srinath C.; Bredella, Miriam A.; Cypess, Aaron M.

    2016-01-01

    The rates of diabetes, obesity, and metabolic disease have reached epidemic proportions worldwide. In recent years there has been renewed interest in combating these diseases not only by modifying energy intake and lifestyle factors, but also by inducing endogenous energy expenditure. This approach has largely been stimulated by the recent recognition that brown adipose tissue (BAT)—long known to promote heat production and energy expenditure in infants and hibernating mammals—also exists in adult humans. This landmark finding relied on the use of clinical fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography, and imaging techniques continue to play a crucial and increasingly central role in understanding BAT physiology and function. Herein, the authors review the origins of BAT imaging, discuss current preclinical and clinical strategies for imaging BAT, and discuss imaging methods that will provide crucial insight into metabolic disease and how it may be treated by modulating BAT activity. © RSNA, 2016 PMID:27322970

  19. Complex interaction between the immune system and adipose tissue (Review).

    PubMed

    Małgorzewicz, Sylwia; Dardzińska, Jolanta Anna; Gnacińska, Maria; Jankun, Jerzy; Bryl, Ewa; Sworczak, Krzysztof

    2014-01-01

    We review the studies on the links between obesity, the immune system and lifestyle (limited or excessive calorie intake) that provoke changes in the current therapeutic course. There is no doubt that the positive energy balance of the body affects the immune cells, and consequently, the changes intracellular pathways, leading to the disruption of their function. Research suggests that metformin, a drug long used to treat diabetes, and an alternative remedy in the treatment of obesity, increases the activity of 5-adenosinemonophosphate (AMP)-activated kinase (AMPK). Thus, this review comes to the conclusion that alongside traditional methods, such as reducing calorie intake and increasing the energy expenditure of the body, the therapeutic outcome may be improved by implementing drugs affecting the activity of AMPK. In future, other new therapeutic options may be available. The targeting receptors or immunocompetent cells residing in adipose tissue may help to reduce the effects of obesity.

  20. Different adipose tissue depots: Metabolic implications and effects of surgical removal.

    PubMed

    Marcadenti, Aline; de Abreu-Silva, Erlon Oliveira

    2015-11-01

    Increased adiposity has been associated to worse metabolic profile, cardiovascular disease, and mortality. There are two main adipose tissue depots in the body, subcutaneous and visceral adipose tissue, which differ in anatomical location. A large body of evidence has shown the metabolic activity of adipose tissue; lipectomy and/or liposuction therefore appear to be alternatives for improving metabolic profile through rapid loss of adipose tissue. However, surgical removal of adipose tissue may be detrimental for metabolism, because subcutaneous adipose tissue has not been associated to metabolic disorders such as insulin resistance and type 2 diabetes mellitus. In addition, animal studies have shown a compensatory growth of adipose tissue in response to lipectomy. This review summarizes the implications of obesity-induced metabolic dysfunction, its relationship with the different adipose tissue depots, and the effects of lipectomy on cardiometabolic risk factors. Copyright © 2015 SEEN. Published by Elsevier España, S.L.U. All rights reserved.

  1. Adipose tissue depot specific differences of PLIN protein content in endurance trained rats

    PubMed Central

    Ramos, Sofhia V.; Turnbull, Patrick C.; MacPherson, Rebecca E. K.

    2016-01-01

    ABSTRACT Adipose tissue is classified as either white (WAT) or brown (BAT) and differs not only by anatomical location but also in function. WAT is the main source of stored energy and releases fatty acids in times of energy demand, whereas BAT plays a role in regulating non-shivering thermogenesis and oxidizes fatty acids released from the lipid droplet. The PLIN family of proteins has recently emerged as being integral in the regulation of fatty acid storage and release in adipose tissue. Previous work has demonstrated that PLIN protein content varies among adipose tissue depots, however an examination of endurance training-induced depot specific changes in PLIN protein expression has yet to be done. Male Sprague-dawley rats (n = 10) underwent 8-weeks of progressive treadmill training (18–25 m/min for 30–60 min at 10% incline) or remained sedentary as control. Following training, under isoflurane induced anesthesia epidydmal (eWAT), inguinal subcutaneous (iWAT) and intrascapular brown adipose tissue (BAT) was excised, and plasma was collected. Endurance training resulted in an increase in BAT PLIN5 and iWAT PLIN3 content, while there was no difference in PLIN protein content in endurance trained eWAT. Interestingly, endurance training resulted in a robust increase in ATGL and CGI-58 in eWAT alone. Together these results suggest the potential of a depot specific function of PLIN3 and PLIN5 in adipose tissue in response to endurance training. PMID:27386161

  2. Adipose tissue macrophages: phenotypic plasticity and diversity in lean and obese states

    PubMed Central

    Morris, David L.; Singer, Kanakadurga; Lumeng, Carey N.

    2015-01-01

    Purpose of review Proinflammatory adipose tissue macrophages (ATMs) contribute to obesity-associated disease morbidity. We will provide an update of the current state of knowledge regarding the phenotypic and functional diversity of ATMs in lean and obese mice and humans. Recent findings The phenotypic diversity of ATMs is now known to include more than two types requiring an expansion of the simple concept of an M2 to M1 shift with obesity. Potential functions for ATMs now include the regulation of fibrosis and response to acute lipolysis in states of caloric restriction. Novel pathways that can potentiate ATM action have been identified, which include inflammasome activation and the response to lipodystrophic adipose tissue. Studies provide a new appreciation for the ability of ATMs to respond dynamically to the adipose tissue microenvironment. Summary ATMs play a key role in shaping the inflammatory milieu within adipose tissue, and it is now apparent that ATM heterogeneity is acutely shaped by the adipose tissue environment. To account for the new findings, we propose a new nomenclature for ATM subtypes that takes into account their diversity. PMID:21587064

  3. Dietary iron overload induces visceral adipose tissue insulin resistance.

    PubMed

    Dongiovanni, Paola; Ruscica, Massimiliano; Rametta, Raffaela; Recalcati, Stefania; Steffani, Liliana; Gatti, Stefano; Girelli, Domenico; Cairo, Gaetano; Magni, Paolo; Fargion, Silvia; Valenti, Luca

    2013-06-01

    Increased iron stores associated with elevated levels of the iron hormone hepcidin are a frequent feature of the metabolic syndrome. The aim of this study was to assess the effect of dietary iron supplementation on insulin resistance and the role of hepcidin in C57Bl/6 male mice fed a standard or iron-enriched diet for 16 weeks. Iron supplementation increased hepatic iron and serum hepcidin fivefold and led to a 40% increase in fasting glucose due to insulin resistance, as confirmed by the insulin tolerance test, and to threefold higher levels of triglycerides. Iron supplemented mice had lower visceral adipose tissue mass estimated by epididymal fat pad, associated with iron accumulation in adipocytes. Decreased insulin signaling, evaluated by the phospho-Akt/Akt ratio, was detected in the visceral adipose tissue of iron overloaded mice, and gene expression analysis of visceral adipose tissue showed that an iron-enriched diet up-regulated iron-responsive genes and adipokines, favoring insulin resistance, whereas lipoprotein lipase was down-regulated. This resulted in hyperresistinemia and increased visceral adipose tissue expression of suppressor of cytokine signaling-3 (Socs3), a target of resistin and hepcidin implicated in insulin resistance. Acute hepcidin administration down-regulated lipoprotein lipase and up-regulated Socs3 in visceral adipose tissue. In conclusion, we characterized a model of dysmetabolic iron overload syndrome in which an iron-enriched diet induces insulin resistance and hypertriglyceridemia and affects visceral adipose tissue metabolism by a mechanism involving hepcidin up-regulation. Copyright © 2013 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  4. Accumulation of adiponectin in inflamed adipose tissues of obese mice.

    PubMed

    Nakatsuji, Hideaki; Kishida, Ken; Sekimoto, Ryohei; Komura, Noriyuki; Kihara, Shinji; Funahashi, Tohru; Shimomura, Iichiro

    2014-04-01

    Adipose tissue inflammation plays an important role in the pathogenesis of obesity-associated complications, such as atherosclerosis. Adiponectin secreted from adipocytes has various beneficial effects including anti-inflammatory effect. Obesity often presents with hypoadiponectinemia. However, the mechanism and adiponectin movement in obesity remain uncharacterized. Here we investigated tissue distribution of adiponectin protein in lean and obese mice. Adiponectin protein levels were evaluated by enzyme-linked immunosorbent assay and western blotting. Adipose tissues were fractionated into mature adipocyte fraction (MAF) and stromal vascular fraction (SVF). Adiponectin protein was detected not only in MAF but also in SVF, which lacks adiponectin mRNA expression, of adipose tissue remarkably. SVF adiponectin protein level was higher in obese mice than in lean mice. The mechanism of adiponectin accumulation was investigated in adiponectin-deficient (APN-KO) mice after injection of plasma from wild-type mice. These mice showed accumulation of exogenous adiponectin, which derived from wild type mice, in adipose tissues, and the adiponectin was more observed in SVF of diet induced obese APN-KO mice than lean APN-KO mice. Among the adiponectin binding proteins, T-cadherin mRNA and protein levels in SVF of obese mice were remarkably higher than in lean mice. Oxidative stress levels were also significantly higher in SVF of obese mice than lean mice. Mechanistically, H2O2 up-regulated T-cadherin mRNA level in murine macrophages. The results demonstrated adiponectin targets to adipose SVF of obese mice. These findings should shed a new light on the pathology of adipose tissue inflammation and hypoadiponectinemia of obesity. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. The impact of adipose tissue-derived factors on the hypothalamic-pituitary-gonadal (HPG) axis.

    PubMed

    Tsatsanis, Christos; Dermitzaki, Eirini; Avgoustinaki, Pavlina; Malliaraki, Niki; Mytaras, Vasilis; Margioris, Andrew N

    2015-01-01

    Adipose tissue produces factors, including adipokines, cytokines and chemokines which, when released, systemically exert endocrine effects on multiple tissues thereby affecting their physiology. Adipokines also affect the hypothalamic-pituitary-gonadal (HPG) axis both centrally, at the hypothalamic-pituitary level, and peripherally acting on the gonads themselves. Among the adipokines, leptin, adiponectin, resistin, chemerin and the peptide kisspeptin have pleiotropic actions on the HPG axis affecting male and female fertility. Furthermore, adipokines and adipose tissue-produced factors readily affect the immune system resulting in inflammation, which in turn impact the HPG axis, thus evidencing a link between metabolic inflammation and fertility. In this review we provide an overview of the existing extensive bibliography on the crosstalk between adipose tissue-derived factors and the HPG axis, with particular focus on the impact of obesity and the metabolic syndrome on gonadal function and fertility.

  6. Physical activity and exercise in the regulation of human adipose tissue physiology.

    PubMed

    Thompson, Dylan; Karpe, Fredrik; Lafontan, Max; Frayn, Keith

    2012-01-01

    Physical activity and exercise are key components of energy expenditure and therefore of energy balance. Changes in energy balance alter fat mass. It is therefore reasonable to ask: What are the links between physical activity and adipose tissue function? There are many complexities. Physical activity is a multifaceted behavior of which exercise is just one component. Physical activity influences adipose tissue both acutely and in the longer term. A single bout of exercise stimulates adipose tissue blood flow and fat mobilization, resulting in delivery of fatty acids to skeletal muscles at a rate well-matched to metabolic requirements, except perhaps in vigorous intensity exercise. The stimuli include adrenergic and other circulating factors. There is a period following an exercise bout when fatty acids are directed away from adipose tissue to other tissues such as skeletal muscle, reducing dietary fat storage in adipose. With chronic exercise (training), there are changes in adipose tissue physiology, particularly an enhanced fat mobilization during acute exercise. It is difficult, however, to distinguish chronic "structural" changes from those associated with the last exercise bout. In addition, it is difficult to distinguish between the effects of training per se and negative energy balance. Epidemiological observations support the idea that physically active people have relatively low fat mass, and intervention studies tend to show that exercise training reduces fat mass. A much-discussed effect of exercise versus calorie restriction in preferentially reducing visceral fat is not borne out by meta-analyses. We conclude that, in addition to the regulation of fat mass, physical activity may contribute to metabolic health through beneficial dynamic changes within adipose tissue in response to each activity bout.

  7. PDGFRα controls the balance of stromal and adipogenic cells during adipose tissue organogenesis.

    PubMed

    Sun, Chengyi; Berry, William L; Olson, Lorin E

    2017-01-01

    Adipose tissue is distributed in depots throughout the body with specialized roles in energy storage and thermogenesis. PDGFRα is a marker of adipocyte precursors, and increased PDGFRα activity causes adipose tissue fibrosis in adult mice. However, the function of PDGFRα during adipose tissue organogenesis is unknown. Here, by analyzing mice with juxtamembrane or kinase domain point mutations that increase PDGFRα activity (V561D or D842V), we found that PDGFRα activation inhibits embryonic white adipose tissue organogenesis in a tissue-autonomous manner. By lineage tracing analysis, we also found that collagen-expressing precursor fibroblasts differentiate into white adipocytes in the embryo. PDGFRα inhibited the formation of adipocytes from these precursors while favoring the formation of stromal fibroblasts. This imbalance between adipocytes and stromal cells was accompanied by overexpression of the cell fate regulator Zfp521. PDGFRα activation also inhibited the formation of juvenile beige adipocytes in the inguinal fat pad. Our data highlight the importance of balancing stromal versus adipogenic cell expansion during white adipose tissue development, with PDGFRα activity coordinating this crucial process in the embryo. © 2017. Published by The Company of Biologists Ltd.

  8. Differential Role of Adipose Tissues in Obesity and Related Metabolic and Vascular Complications

    PubMed Central

    Beneit, Nuria; Díaz-Castroverde, Sabela

    2016-01-01

    This review focuses on the contribution of white, brown, and perivascular adipose tissues to the pathophysiology of obesity and its associated metabolic and vascular complications. Weight gain in obesity generates excess of fat, usually visceral fat, and activates the inflammatory response in the adipocytes and then in other tissues such as liver. Therefore, low systemic inflammation responsible for insulin resistance contributes to atherosclerotic process. Furthermore, an inverse relationship between body mass index and brown adipose tissue activity has been described. For these reasons, in recent years, in order to combat obesity and its related complications, as a complement to conventional treatments, a new insight is focusing on the role of the thermogenic function of brown and perivascular adipose tissues as a promising therapy in humans. These lines of knowledge are focused on the design of new drugs, or other approaches, in order to increase the mass and/or activity of brown adipose tissue or the browning process of beige cells from white adipose tissue. These new treatments may contribute not only to reduce obesity but also to prevent highly prevalent complications such as type 2 diabetes and other vascular alterations, such as hypertension or atherosclerosis. PMID:27766104

  9. NOTE: New tissue substitutes representing cortical bone and adipose tissue in quantitative radiology

    NASA Astrophysics Data System (ADS)

    Sanada, Shigeru; Kawahara, Kazuhiro; Yamamoto, Tomoyuki; Takashima, Tsutomu

    1999-06-01

    To employ quantitative radiology more accurately, we examined phantom materials for cortical bone and adipose tissue as calibration standards and as experimental phantoms. New tissue substitutes for cortical bone and adipose tissue composed of liquid phantom were verified by computing their attenuation coefficients and observing their chemical properties. We showed that a potassium pyrophosphate (K4P2O7) solution for cortical bone was comparable to a dipotassium hydrogen phosphate (K2HPO4) solution. Also, the use of methyl alcohol for adipose tissue was more suitable than ethyl alcohol as a phantom material because of its physical and chemical properties.

  10. Invited review: Pre- and postnatal adipose tissue development in farm animals: from stem cells to adipocyte physiology.

    PubMed

    Louveau, I; Perruchot, M-H; Bonnet, M; Gondret, F

    2016-11-01

    Both white and brown adipose tissues are recognized to be differently involved in energy metabolism and are also able to secrete a variety of factors called adipokines that are involved in a wide range of physiological and metabolic functions. Brown adipose tissue is predominant around birth, except in pigs. Irrespective of species, white adipose tissue has a large capacity to expand postnatally and is able to adapt to a variety of factors. The aim of this review is to update the cellular and molecular mechanisms associated with pre- and postnatal adipose tissue development with a special focus on pigs and ruminants. In contrast to other tissues, the embryonic origin of adipose cells remains the subject of debate. Adipose cells arise from the recruitment of specific multipotent stem cells/progenitors named adipose tissue-derived stromal cells. Recent studies have highlighted the existence of a variety of those cells being able to differentiate into white, brown or brown-like/beige adipocytes. After commitment to the adipocyte lineage, progenitors undergo large changes in the expression of many genes involved in cell cycle arrest, lipid accumulation and secretory functions. Early nutrition can affect these processes during fetal and perinatal periods and can also influence or pre-determinate later growth of adipose tissue. How these changes may be related to adipose tissue functional maturity around birth and can influence newborn survival is discussed. Altogether, a better knowledge of fetal and postnatal adipose tissue development is important for various aspects of animal production, including neonatal survival, postnatal growth efficiency and health.

  11. What's the matter with MAT? Marrow adipose tissue, metabolism, and skeletal health

    PubMed Central

    Scheller, Erica L; Rosen, Clifford J

    2014-01-01

    Marrow adipose tissue (MAT) is functionally distinct from both white and brown adipose tissue and can contribute to systemic and skeletal metabolism. MAT formation is a spatially and temporally defined developmental event, suggesting that MAT is an organ that serves important functions and, like other organs, can undergo pathologic change. The well-documented inverse relationship between MAT and bone mineral density has been interpreted to mean that MAT removal is a possible therapeutic target for osteoporosis. However, the bone and metabolic phenotypes of patients with lipodystrophy argues that retention of MAT may actually be beneficial in some circumstances. Furthermore, MAT may exist in two forms, regulated and constitutive, with divergent responses to hematopoietic and nutritional demands. In this review, we discuss the role of MAT in lipodystrophy, bone loss, and metabolism, and highlight our current understanding of this unique adipose tissue depot. PMID:24650218

  12. Regional differences of insulin action in adipose tissue: insights from in vivo and in vitro studies.

    PubMed

    Giorgino, F; Laviola, L; Eriksson, J W

    2005-01-01

    Adipose tissue is now recognized to have a multitude of functions that are of importance in the regulation of energy balance and substrate metabolism. Different hormones, in particular insulin and catecholamines, govern the storage and utilization of energy in the triglyceride depots. In addition, adipocytes produce several different substances with endocrine or paracrine functions, which regulate the overall energetic homeostasis. With excess energy storage, obesity develops, leading to increased risk for type 2 diabetes and cardiovascular disease. The distribution of body fat appears to be even more important than the total amount of fat. Abdominal and, in particular, visceral adiposity is strongly linked to insulin resistance, type 2 diabetes, hypertension and dyslipidaemia, leading to increased risk of cardiovascular disease. The adverse metabolic impact of visceral fat has been attributed to distinct biological properties of adipocytes in this depot compared with other adipose tissue depots. Indeed, regional variations in the metabolic activity of fat cells have been observed. Furthermore, expression studies aiming at defining the unique biological properties of adipose tissues from distinct anatomical sites have identified depot-related differences in the protein content of fat-produced molecules. In this review we wish to summarize important results from the literature and also some recent data from our own work. The main scope is to describe the biological functions of adipose tissue, and to focus on metabolic, hormonal, and signalling differences between fat depots.

  13. Ex-Vivo Tissues Engineering Modeling for Reconstructive Surgery Using Human Adult Adipose Stem Cells and Polymeric Nanostructured Matrix

    PubMed Central

    Morena, Francesco; Argentati, Chiara; Calzoni, Eleonora; Cordellini, Marino; Emiliani, Carla; D’Angelo, Francesco; Martino, Sabata

    2016-01-01

    The major challenge for stem cell translation regenerative medicine is the regeneration of damaged tissues by creating biological substitutes capable of recapitulating the missing function in the recipient host. Therefore, the current paradigm of tissue engineering strategies is the combination of a selected stem cell type, based on their capability to differentiate toward committed cell lineages, and a biomaterial, that, due to own characteristics (e.g., chemical, electric, mechanical property, nano-topography, and nanostructured molecular components), could serve as active scaffold to generate a bio-hybrid tissue/organ. Thus, effort has been made on the generation of in vitro tissue engineering modeling. Here, we present an in vitro model where human adipose stem cells isolated from lipoaspirate adipose tissue and breast adipose tissue, cultured on polymeric INTEGRA® Meshed Bilayer Wound Matrix (selected based on conventional clinical applications) are evaluated for their potential application for reconstructive surgery toward bone and adipose tissue. We demonstrated that human adipose stem cells isolated from lipoaspirate and breast tissue have similar stemness properties and are suitable for tissue engineering applications. Finally, the overall results highlighted lipoaspirate adipose tissue as a good source for the generation of adult adipose stem cells.

  14. The effects of glucocorticoids on adipose tissue lipid metabolism.

    PubMed

    Peckett, Ashley J; Wright, David C; Riddell, Michael C

    2011-11-01

    Glucocorticoids (GCs) have long been accepted as being catabolic in nature, liberating energy substrates during times of stress to supply the increased metabolic demand of the body. The effects of GCs on adipose tissue metabolism are conflicting, however, because patients with elevated GCs present with central adiposity. We performed an extensive literature review of the effects of GCs on adipose tissue metabolism. The contradictory effects of GCs on lipid metabolism occur through a number of different mechanisms, some of which are well defined and others remain to be elucidated. Firstly, through increases in caloric and dietary fat intake, along with increased hydrolysis of circulating triglycerides (chylomicrons, very low-density lipoproteins) by lipoprotein lipase activity, GCs increase the amount of fatty acids in circulation, which are then available for ectopic fat distribution (liver, muscle, and central adipocytes). Glucocorticoids also increase de novo lipid production in hepatocytes through increased expression of fatty acid synthase. There is some controversy as to whether these same mechanisms occur in adipocytes, thereby contributing to adipose hypertrophy. Glucocorticoids promote preadipocyte conversion to mature adipoc