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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 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

  3. 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. PMID:23834768

  4. Does bariatric surgery improve adipose tissue function?

    PubMed

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

    2016-09-01

    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. © 2016 World Obesity. PMID:27272117

  5. Perivascular adipose tissue contains functional catecholamines

    PubMed Central

    Ayala-Lopez, Nadia; Martini, Marisa; Jackson, William F; Darios, Emma; Burnett, Robert; Seitz, Bridget; Fink, Gregory D; Watts, Stephanie W

    2014-01-01

    The sympathetic nervous system and its neurotransmitter effectors are undeniably important to blood pressure control. We made the novel discovery that perivascular adipose tissue (PVAT) contains significant concentrations of catecholamines. We hypothesized that PVAT contains sufficient releasable catecholamines to affect vascular function. High-pressure liquid chromatography, isometric contractility, immunohistochemistry, whole animal approaches, and pharmacology were used to test this hypothesis. In normal rat thoracic aorta and superior mesenteric artery, the indirect sympathomimetic tyramine caused a concentration-dependent contraction that was dependent on the presence of PVAT. Tyramine stimulated release of norepinephrine (NA), dopamine (DA) and the tryptamine serotonin (5-hydroxytryptamine [5-HT]) from PVAT isolated from both arteries. In both arteries, tyramine-induced concentration-dependent contraction was rightward-shifted and reduced by the noradrenaline transporter inhibitor nisoxetine (1 μmol/L), the vesicular monoamine transporter inhibitor tetrabenazine (10 μmol/L), and abolished by the α adrenoreceptor antagonist prazosin (100 nmol/L). Inhibitors of the DA and 5-HT transporter did not alter tyramine-induced, PVAT-dependent contraction. Removal of the celiac ganglion as a neuronal source of catecholamines for superior mesenteric artery PVAT did not significantly reduce the maximum or shift the concentration-dependent contraction to tyramine. Electrical field stimulation of the isolated aorta was not affected by the presence of PVAT. These data suggest that PVAT components that are independent of sympathetic nerves can release NA in a tyramine-sensitive manner to result in arterial contraction. Because PVAT is intimately apposed to the artery, this raises the possibility of local control of arterial function by PVAT catecholamines. PMID:24904751

  6. The development and endocrine functions of adipose tissue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  7. Bone marrow adipose tissue: formation, function and regulation.

    PubMed

    Suchacki, Karla J; Cawthorn, William P; Rosen, Clifford J

    2016-06-01

    The human body requires an uninterrupted supply of energy to maintain metabolic homeostasis and energy balance. To sustain energy balance, excess consumed calories are stored as glycogen, triglycerides and protein, allowing the body to continue to function in states of starvation and increased energy expenditure. Adipose tissue provides the largest natural store of excess calories as triglycerides and plays an important role as an endocrine organ in energy homeostasis and beyond. This short review is intended to detail the current knowledge of the formation and role of bone marrow adipose tissue (MAT), a largely ignored adipose depot, focussing on the role of MAT as an endocrine organ and highlighting the pharmacological agents that regulate MAT. PMID:27022859

  8. Matrix-Assisted Transplantation of Functional Beige Adipose Tissue.

    PubMed

    Tharp, Kevin M; Jha, Amit K; Kraiczy, Judith; Yesian, Alexandra; Karateev, Grigory; Sinisi, Riccardo; Dubikovskaya, Elena A; Healy, Kevin E; Stahl, Andreas

    2015-11-01

    Novel, clinically relevant, approaches to shift energy balance are urgently needed to combat metabolic disorders such as obesity and diabetes. One promising approach has been the expansion of brown adipose tissues that express uncoupling protein (UCP) 1 and thus can uncouple mitochondrial respiration from ATP synthesis. While expansion of UCP1-expressing adipose depots may be achieved in rodents via genetic and pharmacological manipulations or the transplantation of brown fat depots, these methods are difficult to use for human clinical intervention. We present a novel cell scaffold technology optimized to establish functional brown fat-like depots in vivo. We adapted the biophysical properties of hyaluronic acid-based hydrogels to support the differentiation of white adipose tissue-derived multipotent stem cells (ADMSCs) into lipid-accumulating, UCP1-expressing beige adipose tissue. Subcutaneous implantation of ADMSCs within optimized hydrogels resulted in the establishment of distinct UCP1-expressing implants that successfully attracted host vasculature and persisted for several weeks. Importantly, implant recipients demonstrated elevated core body temperature during cold challenges, enhanced respiration rates, improved glucose homeostasis, and reduced weight gain, demonstrating the therapeutic merit of this highly translatable approach. This novel approach is the first truly clinically translatable system to unlock the therapeutic potential of brown fat-like tissue expansion. PMID:26293504

  9. 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

  10. Adipose tissue fibrosis

    PubMed Central

    Buechler, Christa; Krautbauer, Sabrina; Eisinger, Kristina

    2015-01-01

    The increasing prevalence of obesity causes a major interest in white adipose tissue biology. Adipose tissue cells are surrounded by extracellular matrix proteins whose composition and remodeling is of crucial importance for cell function. The expansion of adipose tissue in obesity is linked to an inappropriate supply with oxygen and hypoxia development. Subsequent activation of hypoxia inducible factor 1 (HIF-1) inhibits preadipocyte differentiation and initiates adipose tissue fibrosis. Thereby adipose tissue growth is limited and excess triglycerides are stored in ectopic tissues. Stressed adipocytes and hypoxia contribute to immune cell immigration and activation which further aggravates adipose tissue fibrosis. There is substantial evidence that adipose tissue fibrosis is linked to metabolic dysfunction, both in rodent models and in the clinical setting. Peroxisome proliferator activated receptor gamma agonists and adiponectin both reduce adipose tissue fibrosis, inflammation and insulin resistance. Current knowledge suggests that antifibrotic drugs, increasing adipose tissue oxygen supply or HIF-1 antagonists will improve adipose tissue function and thereby ameliorate metabolic diseases. PMID:25987952

  11. 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. PMID:25966796

  12. Intramuscular Adipose Tissue, Sarcopenia, and Mobility Function in Older Individuals

    PubMed Central

    Marcus, Robin L.; Addison, Odessa; Dibble, Leland E.; Foreman, K. Bo; Morrell, Glen; LaStayo, Paul

    2012-01-01

    Objective. Intramuscular adipose tissue (IMAT) and sarcopenia may adversely impact mobility function and physical activity. This study determined the association of locomotor muscle structure and function with mobility function in older adults. Method. 109 older adults with a variety of comorbid disease conditions were examined for thigh muscle composition via MRI, knee extensor strength via isometric dynamometry, and mobility function. The contribution of strength, quadriceps lean tissue, and IMAT to explaining the variability in mobility function was examined using multivariate linear regression models. Results. The predictors as a group contributed 27–45% of the variance in all outcome measures; however, IMAT contributed between 8–15% of the variance in all four mobility variables, while lean explained only 5% variance in only one mobility measure. Conclusions. Thigh IMAT, a newly identified muscle impairment appears to be a potent muscle variable related to the ability of older adults to move about in their community. PMID:22500231

  13. n-3 PUFA: bioavailability and modulation of adipose tissue function.

    PubMed

    Kopecky, Jan; Rossmeisl, Martin; Flachs, Pavel; Kuda, Ondrej; Brauner, Petr; Jilkova, Zuzana; Stankova, Barbora; Tvrzicka, Eva; Bryhn, Morten

    2009-11-01

    Adipose tissue has a key role in the development of metabolic syndrome (MS), which includes obesity, type 2 diabetes, dyslipidaemia, hypertension and other disorders. Systemic insulin resistance represents a major factor contributing to the development of MS in obesity. The resistance is precipitated by impaired adipose tissue glucose and lipid metabolism, linked to a low-grade inflammation of adipose tissue and secretion of pro-inflammatory adipokines. Development of MS could be delayed by lifestyle modifications, while both dietary and pharmacological interventions are required for the successful therapy of MS. The n-3 long-chain (LC) PUFA, EPA and DHA, which are abundant in marine fish, act as hypolipidaemic factors, reduce cardiac events and decrease the progression of atherosclerosis. Thus, n-3 LC PUFA represent healthy constituents of diets for patients with MS. In rodents n-3 LC PUFA prevent the development of obesity and impaired glucose tolerance. The effects of n-3 LC PUFA are mediated transcriptionally by AMP-activated protein kinase and by other mechanisms. n-3 LC PUFA activate a metabolic switch toward lipid catabolism and suppression of lipogenesis, i.e. in the liver, adipose tissue and small intestine. This metabolic switch improves dyslipidaemia and reduces ectopic deposition of lipids, resulting in improved insulin signalling. Despite a relatively low accumulation of n-3 LC PUFA in adipose tissue lipids, adipose tissue is specifically linked to the beneficial effects of n-3 LC PUFA, as indicated by (1) the prevention of adipose tissue hyperplasia and hypertrophy, (2) the induction of mitochondrial biogenesis in adipocytes, (3) the induction of adiponectin and (4) the amelioration of adipose tissue inflammation by n-3 LC PUFA. PMID:19698199

  14. [Functional exploration of brown adipose tissue using beta3 agonists].

    PubMed

    Bertin, R; de Marco, F; Blancher, G; Portet, R

    1994-06-01

    In view to utilize beta 3 adrenoceptor agonists for the investigation of body lipid metabolism, a study of the effects of BRL 37344 on the functional activity of the brown adipose tissue was performed in the Rat. It is known that this tissue is the principal site of heat production for nonshivering thermogenesis mainly due to the oxidation of fatty acids under the control of norepinephrine (NA) released from the sympathetic nervous system. In order to stimulate the activity of the tissue, rats were reared at 16 degrees C. When they were one month old, they were divided in two groups; one group received a surgical sympathectomy of the interscapular brown adipose tissue (TABI) (S group); the other group was sham-operated (T group). The resting metabolism was estimated by the continuous measurement of O2 consumption and CO2 release, at an ambient temperature of 25 degrees C. The animal capacity for nonshivering thermogenesis was determined by increased O2 consumption following i.p. administration of NA or BRL 37344. In the S group a large decrease in TABI NA content and a decrease in resting metabolism were observed. In both groups VO2 was increased by the two drugs; the increase was linearly related to the dose of BRL (between 2.5 to 10 micrograms/kg); but it was 3 times as high in the T group as in the S group. Moreover, the effect of BRL was 40 fold greater than the effect of NA. These results seem to indicate that, in cold reared rats, a part of nonshivering thermogenesis may be mediated by the beta 3 receptors of the brown fat. It may be concluded that the rats born in cold conditions are good models to study the role of beta 3 receptors in the energetic activity of this tissue very profuse in infant but not in adult man. PMID:7994586

  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

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

    2016-01-01

    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. 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

  18. BROWN ADIPOSE TISSUE FUNCTION IN SHORT-CHAIN ACYL-COA DEHYDROGENASE DEFICIENT MICE

    PubMed Central

    Skilling, Helen; Coen, Paul M.; Fairfull, Liane; Ferrell, Robert E.; Goodpaster, Bret H.; Vockley, Jerry; Goetzman, Eric S.

    2010-01-01

    Brown adipose tissue is a highly specialized organ that uses mitochondrial fatty acid oxidation to fuel nonshivering thermogenesis. In mice, mutations in the acyl-CoA dehydrogenase family of fatty acid oxidation genes are associated with sensitivity to cold. Brown adipose tissue function has not previously been characterized in these knockout strains. Short-chain acyl-CoA dehydrogenase (SCAD) deficient mice were found to have increased brown adipose tissue mass as well as modest cardiac hypertrophy. Uncoupling protein-1 was reduced by 70% in brown adipose tissue and this was not due to a change in mitochondrial number, nor was it due to decreased signal transduction through protein kinase A which is known to be a major regulator of uncoupling protein-1 expression. PKA activity and in vitro lipolysis were normal in brown adipose tissue, although in white adipose tissue a modest increase in basal lipolysis was seen in SCAD−/ − mice. Finally, an in vivo norepinephrine challenge of brown adipose tissue thermogenesis revealed normal heat production in SCAD−/− mice. These results suggest that reduced brown adipose tissue function is not the major factor causing cold sensitivity in acyl-CoA dehydrogenase knockout strains. We speculate that other mechanisms such as shivering capacity, cardiac function, and reduced hepatic glycogen stores are involved. PMID:20727852

  19. Adipose tissue infiltration in normal-weight subjects and its impact on metabolic function.

    PubMed

    Moreno-Indias, Isabel; Oliva-Olivera, Wilfredo; Omiste, Antonio; Castellano-Castillo, Daniel; Lhamyani, Said; Camargo, Antonio; Tinahones, Francisco J

    2016-06-01

    Discordant phenotypes, metabolically healthy obese and unhealthy normal-weight individuals, are always interesting to provide important insights into the mechanistic link between adipose tissue dysfunction and associated metabolic alterations. Macrophages can release factors that impair the proper activity of the adipose tissue. Thus, studying subcutaneous and visceral adipose tissues, we investigated for the first time the differences in monocyte/macrophage infiltration, inflammation, and adipogenesis of normal-weight subjects who differed in their degree of metabolic syndrome. The study included 92 normal-weight subjects who differed in their degree of metabolic syndrome. Their anthropometric and biochemical parameters were measured. RNA from subcutaneous and visceral adipose tissues was isolated, and mRNA expression of monocyte/macrophage infiltration (CD68, CD33, ITGAM, CD163, EMR-1, CD206, MerTK, CD64, ITGAX), inflammation (IL-6, tumor necrosis factor alpha [TNFα], IL-10, IL-1b, CCL2, CCL3), and adipogenic and lipogenic capacity markers (PPARgamma, FABP4) were measured. Taken together, our data provide evidence of a different degree of macrophage infiltration between the adipose tissues, with a higher monocyte/macrophage infiltration in subcutaneous adipose tissue in metabolically unhealthy normal-weight subjects, whereas visceral adipose tissue remained almost unaffected. An increased macrophage infiltration of adipose tissue and its consequences, such as a decrease in adipogenesis function, may explain why both the obese and normal-weight subjects can develop metabolic diseases or remain healthy. PMID:26829067

  20. Bioengineering Beige Adipose Tissue Therapeutics.

    PubMed

    Tharp, Kevin M; Stahl, Andreas

    2015-01-01

    Unlocking the therapeutic potential of brown/beige adipose tissue requires technological advancements that enable the controlled expansion of this uniquely thermogenic tissue. Transplantation of brown fat in small animal model systems has confirmed the expectation that brown fat expansion could possibly provide a novel therapeutic to combat obesity and related disorders. Expansion and/or stimulation of uncoupling protein-1 (UCP1)-positive adipose tissues have repeatedly demonstrated physiologically beneficial reductions in circulating glucose and lipids. The recent discovery that brown adipose tissue (BAT)-derived secreted factors positively alter whole body metabolism further expands potential benefits of brown or beige/brite adipose expansion. Unfortunately, there are no sources of transplantable BATs for human therapeutic purposes at this time. Recent developments in bioengineering, including novel hyaluronic acid-based hydrogels, have enabled non-immunogenic, functional tissue allografts that can be used to generate large quantities of UCP1-positive adipose tissue. These sophisticated tissue-engineering systems have provided the methodology to develop metabolically active brown or beige/brite adipose tissue implants with the potential to be used as a metabolic therapy. Unlike the pharmacological browning of white adipose depots, implantation of bioengineered UCP1-positive adipose tissues offers a spatially controlled therapeutic. Moving forward, new insights into the mechanisms by which extracellular cues govern stem-cell differentiation and progenitor cell recruitment may enable cell-free matrix implant approaches, which generate a niche sufficient to recruit white adipose tissue-derived stem cells and support their differentiation into functional beige/brite adipose tissues. This review summarizes clinically relevant discoveries in tissue-engineering and biology leading toward the recent development of biomaterial supported beige adipose tissue implants and

  1. Bioengineering Beige Adipose Tissue Therapeutics

    PubMed Central

    Tharp, Kevin M.; Stahl, Andreas

    2015-01-01

    Unlocking the therapeutic potential of brown/beige adipose tissue requires technological advancements that enable the controlled expansion of this uniquely thermogenic tissue. Transplantation of brown fat in small animal model systems has confirmed the expectation that brown fat expansion could possibly provide a novel therapeutic to combat obesity and related disorders. Expansion and/or stimulation of uncoupling protein-1 (UCP1)-positive adipose tissues have repeatedly demonstrated physiologically beneficial reductions in circulating glucose and lipids. The recent discovery that brown adipose tissue (BAT)-derived secreted factors positively alter whole body metabolism further expands potential benefits of brown or beige/brite adipose expansion. Unfortunately, there are no sources of transplantable BATs for human therapeutic purposes at this time. Recent developments in bioengineering, including novel hyaluronic acid-based hydrogels, have enabled non-immunogenic, functional tissue allografts that can be used to generate large quantities of UCP1-positive adipose tissue. These sophisticated tissue-engineering systems have provided the methodology to develop metabolically active brown or beige/brite adipose tissue implants with the potential to be used as a metabolic therapy. Unlike the pharmacological browning of white adipose depots, implantation of bioengineered UCP1-positive adipose tissues offers a spatially controlled therapeutic. Moving forward, new insights into the mechanisms by which extracellular cues govern stem-cell differentiation and progenitor cell recruitment may enable cell-free matrix implant approaches, which generate a niche sufficient to recruit white adipose tissue-derived stem cells and support their differentiation into functional beige/brite adipose tissues. This review summarizes clinically relevant discoveries in tissue-engineering and biology leading toward the recent development of biomaterial supported beige adipose tissue implants and

  2. Regulation of Microvascular Function by Adipose Tissue in Obesity and Type 2 Diabetes: Evidence of an Adipose-Vascular Loop

    PubMed Central

    Zhang, Hanrui; Zhang, Cuihua

    2009-01-01

    In recent years, the general concept has emerged that chronic low-grade inflammation is the condition linking excessive development of adipose tissue and obesity-associated pathologies such as type 2 diabetes and cardiovascular diseases. Obesity and type 2 diabetes are characterized by a diminished production of protective factors such as adiponectin and increased detrimental adipocytokines such as leptin, resistin, interleukin-6 (IL-6), tumor necrosis factor-alpha (TNFα), and monocyte chemoattractant protein-1 (MCP-1) by adipose tissue. Moreover, the evidence that the growth of the fat mass is associated with an accumulation of adipose tissue macrophages and T-lymphocytes has raised the hypothesis that the development of an inflammatory process within the growing fat mass is a primary event involved in the genesis of systemic metabolic and vascular alterations. This crosstalk of adipocyte, macrophage, lymphocyte, endothelial cells, and vascular smooth muscle cells contribute to the production of various cytokines, chemokines, and hormone-like factors, which actively participate in the regulation of vascular function by an endocrine and/or paracrine pattern. Thus, the signaling from perivascular adipose to the blood vessels is emerging as a potential therapeutic target for obesity and diabetes-associated vascular dysfunction. PMID:20098632

  3. 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

  4. 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

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

    PubMed

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

    2016-01-01

    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

  6. 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

  7. 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. PMID:27015538

  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. 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. PMID:27207537

  10. Severe Burn Injury Induces Thermogenically Functional Mitochondria in Murine White Adipose Tissue.

    PubMed

    Porter, Craig; Herndon, David N; Bhattarai, Nisha; Ogunbileje, John O; Szczesny, Bartosz; Szabo, Csaba; Toliver-Kinsky, Tracy; Sidossis, Labros S

    2015-09-01

    Chronic cold exposure induces functionally thermogenic mitochondria in the inguinal white adipose tissue (iWAT) of mice. Whether this response occurs in pathophysiological states remains unclear. The purpose of this study was to determine the impact of severe burn trauma on iWAT mitochondrial function in mice. Male BALB/c mice (10-12 weeks) received full-thickness scald burns to ∼30% of the body surface area. Inguinal white adipose tissue was harvested from mice at 1, 4, 10, 20, and 40 days postinjury. Total and uncoupling protein 1 (UCP1)-dependent mitochondrial thermogenesis were determined in iWAT. Citrate synthase activity was determined as a proxy of mitochondrial abundance. Immunohistochemistry was performed to assess iWAT morphology and UCP1 expression. Uncoupling protein 1-dependent respiration was significantly greater at 4 and 10 days after burn compared with sham, peaking at 20 days after burn (P < 0.001). Citrate synthase activity was threefold greater at 4, 10, 20, and 40 days after burn versus sham (P < 0.05). Per mitochondrion, UCP1 function increased after burn trauma (P < 0.05). After burn trauma, iWAT exhibited numerous multilocular lipid droplets that stained positive for UCP1. The current findings demonstrate the induction of thermogenically competent mitochondria within rodent iWAT in a model of severe burn trauma. These data identify a specific pathology that induces the browning of white adipose tissue in vivo and may offer a mechanistic explanation for the chronic hypermetabolism observed in burn victims. PMID:26009824

  11. Human and Mouse Brown Adipose Tissue Mitochondria Have Comparable UCP1 Function.

    PubMed

    Porter, Craig; Herndon, David N; Chondronikola, Maria; Chao, Tony; Annamalai, Palam; Bhattarai, Nisha; Saraf, Manish K; Capek, Karel D; Reidy, Paul T; Daquinag, Alexes C; Kolonin, Mikhail G; Rasmussen, Blake B; Borsheim, Elisabet; Toliver-Kinsky, Tracy; Sidossis, Labros S

    2016-08-01

    Brown adipose tissue (BAT) plays an important role in mammalian thermoregulation. The component of BAT mitochondria that permits this function is the inner membrane carrier protein uncoupling protein 1 (UCP1). To the best of our knowledge, no studies have directly quantified UCP1 function in human BAT. Further, whether human and rodent BAT have comparable thermogenic function remains unknown. We employed high-resolution respirometry to determine the respiratory capacity, coupling control, and, most importantly, UCP1 function of human supraclavicular BAT and rodent interscapular BAT. Human BAT was sensitive to the purine nucleotide GDP, providing the first direct evidence that human BAT mitochondria have thermogenically functional UCP1. Further, our data demonstrate that human and rodent BAT have similar UCP1 function per mitochondrion. These data indicate that human and rodent BAT are qualitatively similar in terms of UCP1 function. PMID:27508873

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

    PubMed Central

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

    2014-01-01

    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. While PVAT can support inflammation during atherosclerosis via macrophage accumulation, emerging evidence suggests that PVAT also has anti-atherosclerotic properties related to its abilities to induce non-shivering thermogenesis and metabolize fatty acids. We here discuss the accumulated knowledge of PVAT biology, and related research on models of hypertension and atherosclerosis. PMID:24833795

  13. Perivascular Adipose Tissue

    PubMed Central

    Maille, Nicole; Clas, Darren; Osol, George

    2015-01-01

    Perivascular adipose tissue (PVAT) contributes to vasoregulation. The role of this adipose tissue bed in pregnancy has not been examined. Here, we tested the hypothesis that PVAT in pregnant rats decreases resistance artery tone. Mesenteric arteries from nonpregnant (NP) and late pregnant (LP) rats were exposed to phenylephrine (PHE) or KCl in the presence (+) versus absence (−) of PVAT. The LP PVAT(+) vessels showed a 44% decrease in sensitivity to PHE in the presence of PVAT. There was no attenuation of the contractile response to KCl when PVAT was present. The LP arteries perfused with LP or NP PVAT underwent vasodilation; unexpectedly, NP vessels in the presence of PVAT from LP rats sustained a 48% vasoconstriction. The PVAT attenuates vasoconstriction by a mechanism that involves hyperpolarization. The vasoconstriction observed when nonpregnant vessels were exposed to pregnant PVAT suggests pregnant vessels adapt to the vasoconstricting influence of pregnant PVAT. PMID:25527422

  14. 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

  15. Diabetes impairs adipose tissue-derived stem cell function and efficiency in promoting wound healing.

    PubMed

    Cianfarani, Francesca; Toietta, Gabriele; Di Rocco, Giuliana; Cesareo, Eleonora; Zambruno, Giovanna; Odorisio, Teresa

    2013-01-01

    Adipose tissue-derived stem cells (ASCs) are gaining increasing consideration in tissue repair therapeutic application. Recent evidence indicates that ASCs enhance skin repair in animal models of impaired wound healing. To assess the therapeutic activity of autologous vs. allogeneic ASCs in the treatment of diabetic ulcers, we functionally characterized diabetic ASCs and investigated their potential to promote wound healing with respect to nondiabetic ones. Adipose tissue-derived cells from streptozotocin-induced type 1 diabetic mice were analyzed either freshly isolated as stromal vascular fraction (SVF), or following a single passage of culture (ASCs). Diabetic ASCs showed decreased proliferative potential and migration. Expression of surface markers was altered in diabetic SVF and cultured ASCs, with a reduction in stem cell marker-positive cells. ASCs from diabetic mice released lower amounts of hepatocyte growth factor, vascular endothelial growth factor (VEGF)-A, and insulin-like growth factor-1, growth factors playing important roles in skin repair. Accordingly, the supernatant of diabetic ASCs manifested reduced capability to promote keratinocyte and fibroblast proliferation and migration. Therapeutic potential of diabetic SVF administered to wounds of diabetic mice was blunted as compared with cells isolated from nondiabetic mice. Our data indicate that diabetes alters ASC intrinsic properties and impairs their function, thus affecting therapeutic potential in the autologous treatment for diabetic ulcers. PMID:23627689

  16. 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

  17. Exercise regulation of adipose tissue.

    PubMed

    Stanford, Kristin I; Goodyear, Laurie J

    2016-01-01

    Exercise training results in adaptations to numerous organ systems and offers protection against metabolic disorders including obesity and type 2 diabetes, and recent reports suggest that adipose tissue may play a role in these beneficial effects of exercise on overall health. Multiple studies have investigated the effects of exercise training on both white adipose tissue (WAT) and brown adipose tissue (BAT), as well as the induction of beige adipocytes. Studies from both rodents and humans show that there are exercise training-induced changes in WAT including decreased cell size and lipid content, and increased mitochondrial activity. In rodents, exercise training causes an increased beiging of WAT. Whether exercise training causes a beiging of human scWAT, as well as which factors contribute to the exercise-induced beiging of WAT are areas of current investigation. Studies investigating the effects of exercise training on BAT mass and function have yielded conflicting data, and hence, is another area of intensive investigation. This review will focus on studies aimed at elucidating the mechanisms regulating exercise training induced-adaptations to adipose tissue. PMID:27386159

  18. Trypanosoma brucei Parasites Occupy and Functionally Adapt to the Adipose Tissue in Mice.

    PubMed

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

    2016-06-01

    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. 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. PMID:27237364

  19. Regulation of brown adipose tissue recruitment, metabolism and thermogenic function by peroxisome proliferator-activated receptor γ

    PubMed Central

    Bolsoni-Lopes, Andressa; Deshaies, Yves; Festuccia, William T

    2015-01-01

    Brown adipose tissue contributes importantly to homeothermy and energy balance in rodents due its ability under demand to produce heat through a process denominated nonshivering thermogenesis. Such thermogenic ability of brown adipocytes relies on the activity of mitochondrial uncoupling protein 1 that, when properly activated, dissipates energy from oxidative metabolism as heat. Brown adipose tissue sympathetic innervation through norepinephrine release not only induces brown adipocyte lipolysis and thermogenesis, but also acts as the major determinant of tissue mass, cellularity and mitochondrial content. Several pieces of evidence gathered over the years indicate that, in addition to tissue sympathetic innervation, the nuclear receptor peroxisome proliferator-activated receptor γ plays an important role in regulating the development, metabolism and thermogenic function of brown adipose tissue. Herein we review the main evidence supporting such key role of peroxisome proliferator-activated receptor γ to brown fat biology and discuss the future directions of this important area of research. PMID:27227067

  20. Effects of fetal and neonatal exposure to nicotine on blood pressure and perivascular adipose tissue function in adult life.

    PubMed

    Gao, Yu-Jing; Holloway, Alison C; Su, Li-Ying; Takemori, Kumiko; Lu, Chao; Lee, Robert M K W

    2008-08-20

    In Wistar rats, maternal exposure to nicotine was shown to impair the inhibitory function of perivascular adipose tissue on vascular contractility in the aorta of the offspring. It is not known whether an impairment of perivascular adipose tissue function occurs in smaller arteries, and whether the control of blood pressure is affected. Here we studied the blood pressure effects and the alteration of perivascular adipose tissue function in mesenteric arteries of the offspring born to Wistar-Kyoto rat (WKY) dams exposed to nicotine. Nulliparous female WKY rats were given either nicotine bitartrate (1 mg/kg/day) or saline (vehicle) by subcutaneous injection 2 weeks prior to mating, during pregnancy and until weaning. Blood pressure of the offspring and functional studies with mesenteric arteries were conducted. Tissue samples (thoracic aorta, mesenteric arteries, and kidneys) were collected for morphological and immunohistochemical examinations. Blood pressure increased from 14 weeks of age onwards in the offspring born to nicotine-exposed dams. Nicotine-exposed offspring showed a significant increase in the number of brown adipocytes in aortic perivascular adipose tissue relative to control offspring. In mesenteric arteries from control offspring, contractile responses induced by phenylephrine, serotonin, and 9,11-dideoxy-11alpha, 9alpha-epoxymethanoprostaglandin F(2)alpha (U44619) were significantly attenuated in the presence of perivascular adipose tissue, an effect not observed in the nicotine-exposed tissues. Endothelium-dependent relaxation responses to carbachol, kidney weight, the total number of nephrons and glomerulus' size were comparable in nicotine and saline groups. We conclude that fetal and neonatal exposure to nicotine caused blood pressure elevation. Alterations in perivascular adipose tissue composition and modulatory function are some of the mechanisms associated with this blood pressure increase. PMID:18647709

  1. Fibrosis and Adipose Tissue Dysfunction

    PubMed Central

    Sun, Kai; Tordjman, Joan; Clément, Karine; Scherer, Philipp E.

    2013-01-01

    Fibrosis is increasingly appreciated as a major player in adipose tissue dysfunction. In rapidly expanding adipose tissue, pervasive hypoxia leads to an induction of HIF1α that in turn leads to a potent pro-fibrotic transcriptional program. The pathophysiological impact of adipose tissue fibrosis is likely to play an equally important role on systemic metabolic alterations as fibrotic conditions play in the liver, heart and kidney. Here, we discuss recent advances in our understanding of the genesis, modulation and systemic impact of excessive extracellular matrix (ECM) accumulation in adipose tissue of both rodents and humans and the ensuing impact on metabolic dysfunction. PMID:23954640

  2. Dependence of brown adipose tissue function on CD36-mediated coenzyme Q uptake.

    PubMed

    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; Van, An-Angela Ngoc; Park, Michael J; Yun, Dawee; Chan, Karen; Yu, Angela; Vuong, Peter; Febbraio, Maria; Nomura, Daniel K; Napoli, Joseph L; Brand, Martin D; Stahl, Andreas

    2015-02-01

    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 synthesize CoQ mostly 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 are 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 nonshivering thermogenesis. Together, these data reveal an important new role for the systemic transport of CoQ to BAT and its function in thermogenesis. PMID:25620701

  3. 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

  4. Generation of a functional liver tissue mimic using adipose stromal vascular fraction cell-derived vasculatures

    PubMed Central

    Nunes, S. S.; Maijub, J. G.; Krishnan, L.; Ramakrishnan, V. M.; Clayton, L. R.; Williams, S. K.; Hoying, J. B.; Boyd, N. L.

    2013-01-01

    One of the major challenges in cell implantation therapies is to promote integration of the microcirculation between the implanted cells and the host. We used adipose-derived stromal vascular fraction (SVF) cells to vascularize a human liver cell (HepG2) implant. We hypothesized that the SVF cells would form a functional microcirculation via vascular assembly and inosculation with the host vasculature. Initially, we assessed the extent and character of neovasculatures formed by freshly isolated and cultured SVF cells and found that freshly isolated cells have a higher vascularization potential. Generation of a 3D implant containing fresh SVF and HepG2 cells formed a tissue in which HepG2 cells were entwined with a network of microvessels. Implanted HepG2 cells sequestered labeled LDL delivered by systemic intravascular injection only in SVF-vascularized implants demonstrating that SVF cell-derived vasculatures can effectively integrate with host vessels and interface with parenchymal cells to form a functional tissue mimic. PMID:23828203

  5. Adipose tissue extract promotes adipose tissue regeneration in an adipose tissue engineering chamber model.

    PubMed

    Lu, Zijing; Yuan, Yi; Gao, Jianhua; Lu, Feng

    2016-05-01

    An adipose tissue engineering chamber model of spontaneous adipose tissue generation from an existing fat flap has been described. However, the chamber does not completely fill with adipose tissue in this model. Here, the effect of adipose tissue extract (ATE) on adipose tissue regeneration was investigated. In vitro, the adipogenic and angiogenic capacities of ATE were evaluated using Oil Red O and tube formation assays on adipose-derived stem cells (ASCs) and rat aortic endothelial cells (RAECs), respectively. In vivo, saline or ATE was injected into the adipose tissue engineering chamber 1 week after its implantation. At different time points post-injection, the contents were morphometrically, histologically, and immunohistochemically evaluated, and the expression of growth factors and adipogenic genes was analyzed by enzyme-linked immunosorbent assay (ELISA) and quantitative real-time PCR. With the exception of the baseline control group, in which fat flaps were not inserted into a chamber, the total volume of fat flap tissue increased significantly in all groups, especially in the ATE group. Better morphology and structure, a thinner capsule, and more vessels were observed in the ATE group than in the control group. Expression of angiogenic growth factors and adipogenic markers were significantly higher in the ATE group. ATE therefore significantly promoted adipose tissue regeneration and reduced capsule formation in an adipose tissue engineering chamber model. These data suggest that ATE provides a more angiogenic and adipogenic microenvironment for adipose tissue formation by releasing various cytokines and growth factors that also inhibit capsule formation. PMID:26678825

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

    PubMed Central

    Ma, Xinran; Xu, Lingyan; Mueller, Elisabetta

    2016-01-01

    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. PMID:26957608

  7. 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. PMID:26957608

  8. The adipose organ: morphological perspectives of adipose tissues.

    PubMed

    Cinti, S

    2001-08-01

    Anatomically, an organ is defined as a series of tissues which jointly perform one or more interconnected functions. The adipose organ qualifies for this definition as it is made up of two tissue types, the white and brown adipose tissues, which collaborate in partitioning the energy contained in lipids between thermogenesis and the other metabolic functions. In rats and mice the adipose organ consists of several subcutaneous and visceral depots. Some areas of these depots are brown and correspond to brown adipose tissue, while many are white and correspond to white adipose tissue. The number of brown adipocytes found in white areas varies with age, strain of animal and environmental conditions. Brown and white adipocyte precursors are morphologically dissimilar. Together with a rich vascular supply, brown areas receive abundant noradrenergic parenchymal innervation. The gross anatomy and histology of the organ vary considerably in different physiological (cold acclimation, warm acclimation, fasting) and pathological conditions such as obesity; many important genes, such as leptin and uncoupling protein-1, are also expressed very differently in the two cell types. These basic mechanisms should be taken into account when addressing the physiopathology of obesity and its treatment. PMID:11681806

  9. 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. PMID:27120716

  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. PMID:27192989

  12. Influencing Factors of Thermogenic Adipose Tissue Activity.

    PubMed

    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

  13. 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

  14. Dicer1-miR-328-Bace1 signalling controls brown adipose tissue differentiation and function.

    PubMed

    Oliverio, Matteo; Schmidt, Elena; Mauer, Jan; Baitzel, Catherina; Hansmeier, Nils; Khani, Sajjad; Konieczka, Sandra; Pradas-Juni, Marta; Brodesser, Susanne; Van, Trieu-My; Bartsch, Deniz; Brönneke, Hella S; Heine, Markus; Hilpert, Hans; Tarcitano, Emilio; Garinis, George A; Frommolt, Peter; Heeren, Joerg; Mori, Marcelo A; Brüning, Jens C; Kornfeld, Jan-Wilhelm

    2016-03-01

    Activation of brown adipose tissue (BAT) controls energy homeostasis in rodents and humans and has emerged as an innovative strategy for the treatment of obesity and type 2 diabetes mellitus. Here we show that ageing- and obesity-associated dysfunction of brown fat coincides with global microRNA downregulation due to reduced expression of the microRNA-processing node Dicer1. Consequently, heterozygosity of Dicer1 in BAT aggravated diet-induced-obesity (DIO)-evoked deterioration of glucose metabolism. Analyses of differential microRNA expression during preadipocyte commitment and mouse models of progeria, longevity and DIO identified miR-328 as a regulator of BAT differentiation. Reducing miR-328 blocked preadipocyte commitment, whereas miR-328 overexpression instigated BAT differentiation and impaired muscle progenitor commitment-partly through silencing of the β-secretase Bace1. Loss of Bace1 enhanced brown preadipocyte specification in vitro and was overexpressed in BAT of obese and progeroid mice. In vivo Bace1 inhibition delayed DIO-induced weight gain and improved glucose tolerance and insulin sensitivity. These experiments reveal Dicer1-miR-328-Bace1 signalling as a determinant of BAT function, and highlight the potential of Bace1 inhibition as a therapeutic approach to improve not only neurodegenerative diseases but also ageing- and obesity-associated impairments of BAT function. PMID:26900752

  15. 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

  16. Increased oxidative stress impairs adipose tissue function in sphingomyelin synthase 1 null mice.

    PubMed

    Yano, Masato; Yamamoto, Tadashi; 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

  17. 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.

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

    PubMed Central

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

    2016-01-01

    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. PMID:27491409

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

    PubMed

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

    2016-01-01

    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. PMID:27491409

  20. Perivascular Adipose Tissue Inhibits Endothelial Function of Rat Aortas via Caveolin-1

    PubMed Central

    Lee, Michelle Hui-Hsin; Chen, Shiu-Jen

    2014-01-01

    Perivascular adipose tissue (PVAT)-derived factors have been proposed to play an important role in the pathogenesis of atherosclerosis. Caveolin-1 (Cav-1), occupying the calcium/calmodulin binding site of endothelial NO synthase (eNOS) and then inhibiting nitric oxide (NO) production, is also involved in the development of atherosclerosis. Thus, we investigated whether PVAT regulated vascular tone via Cav-1 and/or endothelial NO pathways. Isometric tension studies were carried out in isolated thoracic aortas from Wistar rats in the presence and absence of PVAT. Concentration-response curves of phenylephrine, acetylcholine, and sodium nitroprusside were illustrated to examine the vascular reactivity and endothelial function. The protein expressions of eNOS and Cav-1 were also examined in aortic homogenates. Our results demonstrated that PVAT significantly enhanced vasoconstriction and inhibited vasodilatation via endothelium-dependent mechanism. The aortic NO production was diminished after PVAT treatment, whereas protein expression and activity of eNOS were not significantly affected. In addition, Cav-1 protein expression was significantly increased in aortas with PVAT transfer. Furthermore, a caveolae depleter methyl-β-cyclodextrin abolished the effect of PVAT on the enhancement of vasoconstriction, and reversed the impairment of aortic NO production. In conclusion, unknown factor(s) released from PVAT may inhibit endothelial NO production and induce vasocontraction via an increase of Cav-1 protein expression. PMID:24926683

  1. 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. PMID:27059327

  2. 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. PMID:26823340

  3. Different Anti-Contractile Function and Nitric Oxide Production of Thoracic and Abdominal Perivascular Adipose Tissues

    PubMed Central

    Victorio, Jamaira A.; Fontes, Milene T.; Rossoni, Luciana V.; Davel, Ana P.

    2016-01-01

    Divergent phenotypes between the perivascular adipose tissue (PVAT) surrounding the abdominal and the thoracic aorta might be implicated in regional aortic differences, such as susceptibility to atherosclerosis. Although PVAT of the thoracic aorta exhibits anti-contractile function, the role of PVAT in the regulation of the vascular tone of the abdominal aorta is not well defined. In the present study, we compared the anti-contractile function, nitric oxide (NO) availability, and reactive oxygen species (ROS) formation in PVAT and vessel walls of abdominal and thoracic aorta. Abdominal and thoracic aortic tissue from male Wistar rats were used to perform functional and molecular experiments. PVAT reduced the contraction evoked by phenylephrine in the absence and presence of endothelium in the thoracic aorta, whereas this anti-contractile effect was not observed in the abdominal aorta. Abdominal PVAT exhibited a reduction in endothelial NO synthase (eNOS) expression compared with thoracic PVAT, without differences in eNOS expression in the vessel walls. In agreement with this result, NO production evaluated in situ using 4,5-diaminofluorescein was less pronounced in abdominal compared with thoracic aortic PVAT, whereas no significant difference was observed for endothelial NO production. Moreover, NOS inhibition with L-NAME enhanced the phenylephrine-induced contraction in endothelial-denuded rings with PVAT from thoracic but not abdominal aorta. ROS formation and lipid peroxidation products evaluated through the quantification of hydroethidine fluorescence and 4-hydroxynonenal adducts, respectively, were similar between PVAT and vessel walls from the abdominal and thoracic aorta. Extracellular superoxide dismutase (SOD) expression was similar between the vessel walls and PVAT of the abdominal and thoracic aorta. However, Mn-SOD levels were reduced, while CuZn-SOD levels were increased in abdominal PVAT compared with thoracic aortic PVAT. In conclusion, our results

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

    PubMed

    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

    2015-07-01

    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

  5. Increased Reliance on Muscle-based Thermogenesis upon Acute Minimization of Brown Adipose Tissue Function.

    PubMed

    Bal, Naresh C; Maurya, Santosh K; Singh, Sushant; Wehrens, Xander H T; Periasamy, Muthu

    2016-08-12

    Skeletal muscle has been suggested as a site of nonshivering thermogenesis (NST) besides brown adipose tissue (BAT). Studies in birds, which do not contain BAT, have demonstrated the importance of skeletal muscle-based NST. However, muscle-based NST in mammals remains poorly characterized. We recently reported that sarco/endoplasmic reticulum Ca(2+) cycling and that its regulation by SLN can be the basis for muscle NST. Because of the dominant role of BAT-mediated thermogenesis in rodents, the role of muscle-based NST is less obvious. In this study, we investigated whether muscle will become an important site of NST when BAT function is conditionally minimized in mice. We surgically removed interscapular BAT (iBAT, which constitutes ∼70% of total BAT) and exposed the mice to prolonged cold (4 °C) for 9 days. The iBAT-ablated mice were able to maintain optimal body temperature (∼35-37 °C) during the entire period of cold exposure. After 4 days in the cold, both sham controls and iBAT-ablated mice stopped shivering and resumed routine physical activity, indicating that they are cold-adapted. The iBAT-ablated mice showed higher oxygen consumption and decreased body weight and fat mass, suggesting an increased energy cost of cold adaptation. The skeletal muscles in these mice underwent extensive remodeling of both the sarcoplasmic reticulum and mitochondria, including alteration in the expression of key components of Ca(2+) handling and mitochondrial metabolism. These changes, along with increased sarcolipin expression, provide evidence for the recruitment of NST in skeletal muscle. These studies collectively suggest that skeletal muscle becomes the major site of NST when BAT activity is minimized. PMID:27298322

  6. Seasonal changes in brown adipose tissue mitochondria in a mammalian hibernator: from gene expression to function.

    PubMed

    Ballinger, Mallory A; Hess, Clair; Napolitano, Max W; Bjork, James A; Andrews, Matthew T

    2016-08-01

    Brown adipose tissue (BAT) is a thermogenic organ that is vital for hibernation in mammals. Throughout the hibernation season, BAT mitochondrial uncoupling protein 1 (UCP1) enables rapid rewarming from hypothermic torpor to periodic interbout arousals (IBAs), as energy is dissipated as heat. However, BAT's unique ability to rewarm the body via nonshivering thermogenesis is not necessary outside the hibernation season, suggesting a potential seasonal change in the regulation of BAT function. Here, we examined the BAT mitochondrial proteome and mitochondrial bioenergetics in the thirteen-lined ground squirrel (Ictidomys tridecemlineatus) across four time points: spring, fall, torpor, and IBA. Relative mitochondrial content of BAT was estimated by measuring BAT pad mass, UCP1 protein content, and mitochondrial DNA (mtDNA) copy number. BAT mtDNA content was significantly lower in spring compared with torpor and IBA (P < 0.05). UCP1 mRNA and protein levels were highest during torpor and IBA. Respiration rates of isolated BAT mitochondria were interrogated at each complex of the electron transport chain. Respiration at complex II was significantly higher in torpor and IBA compared with spring (P < 0.05), suggesting an enhancement in mitochondrial respiratory capacity during hibernation. Additionally, proteomic iTRAQ labeling identified 778 BAT mitochondrial proteins. Proteins required for mitochondrial lipid translocation and β-oxidation were upregulated during torpor and IBA and downregulated in spring. These data imply that BAT bioenergetics and mitochondrial content are not static across the year, despite the year-round presence of UCP1. PMID:27225952

  7. Adiposity is associated with DNA methylation profile in adipose tissue

    PubMed Central

    Agha, Golareh; Houseman, E Andres; Kelsey, Karl T; Eaton, Charles B; Buka, Stephen L; Loucks, Eric B

    2015-01-01

    Background: Adiposity is a risk factor for type 2 diabetes and cardiovascular disease, suggesting an important role for adipose tissue in the development of these conditions. The epigenetic underpinnings of adiposity are not well understood, and studies of DNA methylation in relation to adiposity have rarely focused on target adipose tissue. Objectives were to evaluate whether genome-wide DNA methylation profiles in subcutaneous adipose tissue and peripheral blood leukocytes are associated with measures of adiposity, including central fat mass, body fat distribution and body mass index. Methods: Participants were 106 men and women (mean age 47 years) from the New England Family Study. DNA methylation was evaluated using the Infinium HumanMethylation450K BeadChip. Adiposity phenotypes included dual-energy X-ray absorptiometry-assessed android fat mass, android:gynoid fat ratio and trunk:limb fat ratio, as well as body mass index. Results: Adipose tissue genome-wide DNA methylation profiles were associated with all four adiposity phenotypes, after adjusting for race, sex and current smoking (omnibus p-values <0.001). After further adjustment for adipose cell-mixture effects, associations with android fat mass, android:gynoid fat ratio, and trunk:limb fat ratio remained. In gene-specific analyses, adiposity phenotypes were associated with adipose tissue DNA methylation in several genes that are biologically relevant to the development of adiposity, such as AOC3, LIPE, SOD3, AQP7 and CETP. Blood DNA methylation profiles were not associated with adiposity, before or after adjustment for blood leukocyte cell mixture effects. Conclusion: Findings show that DNA methylation patterns in adipose tissue are associated with adiposity. PMID:25541553

  8. Triacylglycerol metabolism in adipose tissue

    PubMed Central

    Ahmadian, Maryam; Duncan, Robin E; Jaworski, Kathy; Sarkadi-Nagy, Eszter; Sul, Hei Sook

    2009-01-01

    Triacylglycerol (TAG) in adipose tissue serves as the major energy storage form in higher eukaryotes. Obesity, resulting from excess white adipose tissue, has increased dramatically in recent years resulting in a serious public health problem. Understanding of adipocyte-specific TAG synthesis and hydrolysis is critical to the development of strategies to treat and prevent obesity and its closely associated diseases, for example, Type 2 diabetes, hypertension and atherosclerosis. In this review, we present an overview of the major enzymes in TAG synthesis and lipolysis, including the recent discovery of a novel adipocyte TAG hydrolase. PMID:19194515

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

    PubMed

    Yan, Ming; Audet-Walsh, Étienne; Manteghi, Sanaz; Rosa Dufour, Catherine; 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. PMID:27151976

  10. Adipose Tissue - Adequate, Accessible Regenerative Material.

    PubMed

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

    2015-11-01

    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

  11. 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

  12. Methods in Enzymology (MIE): Methods of Adipose Tissue Biology-

    PubMed Central

    Berry, Ryan; Church, Christopher; Gericke, Martin T.; Jeffery, Elise; Colman, Laura; Rodeheffer, Matthew S.

    2014-01-01

    Adipose tissue is an endocrine organ that specializes in lipid metabolism and is distributed throughout the body in distinct white adipose tissue (WAT) and brown adipose tissue (BAT) depots. These tissues have opposing roles in lipid metabolism with WAT storing excessive caloric intake in the form of lipid, and BAT burning lipid through non-shivering thermogenesis. As accumulation of lipid in mature adipocytes of WAT leads to obesity and increased risk of comorbidity (Pi-Sunyer et al., 1998), detailed understanding of the mechanisms of BAT activation and WAT accumulation could produce therapeutic strategies for combatting metabolic pathologies. As morphological changes accompany alterations in adipose function, imaging of adipose tissue is one of the most important tools for understanding how adipose tissue mass fluctuates in response to various physiological contexts. Therefore, this chapter details several methods of processing and imaging adipose tissue, including brightfield colorimetric imaging of paraffin sectioned adipose tissue with a detailed protocol for automated adipocyte size analysis; fluorescent imaging of paraffin and frozen sectioned adipose tissue; and confocal fluorescent microscopy of whole mounted adipose tissue. We have also provided many example images showing results produced using each protocol, as well as commentary on the strengths and limitations of each approach. PMID:24480341

  13. [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. PMID:27234867

  14. 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. PMID:27073214

  15. Obesity-associated Inflammation Induces microRNA-155 Expression in Adipocytes and Adipose Tissue: Outcome on Adipocyte Function.

    PubMed

    Karkeni, Esma; Astier, Julien; Tourniaire, Franck; El Abed, Mouna; Romier, Béatrice; Gouranton, Erwan; Wan, Lin; Borel, Patrick; Salles, Jérôme; Walrand, Stéphane; Ye, Jianping; Landrier, Jean-François

    2016-04-01

    miR-155 expression is induced in adipocytes and adipose tissue submitted to inflammatory conditions in obesity context in murine and human models and participate to a pro-inflammatory loop by targeting PPARg. PMID:26829440

  16. 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

  17. 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. PMID:25150689

  18. 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

  19. 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. PMID:16309937

  20. NAMPT-Mediated NAD(+) Biosynthesis in Adipocytes Regulates Adipose Tissue Function and Multi-organ Insulin Sensitivity in Mice.

    PubMed

    Stromsdorfer, Kelly L; Yamaguchi, Shintaro; Yoon, Myeong Jin; Moseley, Anna C; Franczyk, Michael P; Kelly, Shannon C; Qi, Nathan; Imai, Shin-Ichiro; Yoshino, Jun

    2016-08-16

    Obesity is associated with adipose tissue dysfunction and multi-organ insulin resistance. However, the mechanisms of such obesity-associated systemic metabolic complications are not clear. Here, we characterized mice with adipocyte-specific deletion of nicotinamide phosphoribosyltransferase (NAMPT), a rate-limiting NAD(+) biosynthetic enzyme known to decrease in adipose tissue of obese and aged rodents and people. We found that adipocyte-specific Nampt knockout mice had severe insulin resistance in adipose tissue, liver, and skeletal muscle and adipose tissue dysfunction, manifested by increased plasma free fatty acid concentrations and decreased plasma concentrations of a major insulin-sensitizing adipokine, adiponectin. Loss of Nampt increased phosphorylation of CDK5 and PPARγ (serine-273) and decreased gene expression of obesity-linked phosphorylated PPARγ targets in adipose tissue. These deleterious alterations were normalized by administering rosiglitazone or a key NAD(+) intermediate, nicotinamide mononucleotide (NMN). Collectively, our results provide important mechanistic and therapeutic insights into obesity-associated systemic metabolic derangements, particularly multi-organ insulin resistance. PMID:27498863

  1. Visceral Adiposity Index: An Indicator of Adipose Tissue Dysfunction

    PubMed Central

    2014-01-01

    The Visceral Adiposity Index (VAI) has recently proven to be an indicator of adipose distribution and function that indirectly expresses cardiometabolic risk. In addition, VAI has been proposed as a useful tool for early detection of a condition of cardiometabolic risk before it develops into an overt metabolic syndrome. The application of the VAI in particular populations of patients (women with polycystic ovary syndrome, patients with acromegaly, patients with NAFLD/NASH, patients with HCV hepatitis, patients with type 2 diabetes, and general population) has produced interesting results, which have led to the hypothesis that the VAI could be considered a marker of adipose tissue dysfunction. Unfortunately, in some cases, on the same patient population, there is conflicting evidence. We think that this could be mainly due to a lack of knowledge of the application limits of the index, on the part of various authors, and to having applied the VAI in non-Caucasian populations. Future prospective studies could certainly better define the possible usefulness of the VAI as a predictor of cardiometabolic risk. PMID:24829577

  2. 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

    2015-01-01

    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

  3. [Cancer cachexia and white adipose tissue browning].

    PubMed

    Zhang, S T; Yang, H M

    2016-08-01

    Cancer cachexia occurs in a majority of advanced cancer patients. These patients with impaired physical function are unable to tolerance cancer treatment well and have a significantly reduced survival rate. Currently, there is no effective clinical treatment available for cancer cachexia, therefore, it is necessary to clarify the molecular mechanisms of cancer cachexia, moreover, new therapeutic targets for cancer cachexia treatment are urgently needed. Very recent studies suggest that, during cancer cachexia, white adipose tissue undergo a 'browning' process, resulting in increased lipid mobilization and energy expenditure, which may be necessary for the occurrence of cancer cachexia. In this article, we summarize the definition and characteristics of cancer cachexia and adipose tissue 'browning', then, we discuss the new study directions presented in latest research. PMID:27531474

  4. Marrow Adipose Tissue: Trimming the Fat.

    PubMed

    Scheller, Erica L; Cawthorn, William P; Burr, Aaron A; Horowitz, Mark C; MacDougald, Ormond A

    2016-06-01

    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 the development of bone metastases. The diversity of these functions highlights the breadth of the potential impact of MAT on health and disease. PMID:27094502

  5. 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

  6. Differential responses of white adipose tissue and brown adipose tissue to caloric restriction in rats.

    PubMed

    Okita, Naoyuki; Hayashida, Yusuke; Kojima, Yumiko; Fukushima, Mayumi; Yuguchi, Keiko; Mikami, Kentaro; Yamauchi, Akiko; Watanabe, Kyoko; Noguchi, Mituru; Nakamura, Megumi; Toda, Toshifusa; Higami, Yoshikazu

    2012-05-01

    Caloric restriction (CR) slows the aging process and extends longevity, but the exact underlying mechanisms remain debatable. It has recently been suggested that the beneficial action of CR may be mediated in part by adipose tissue remodeling. Mammals have two types of adipose tissue: white adipose tissue (WAT) and brown adipose tissue (BAT). In this study, proteome analysis using two-dimensional gel electrophoresis combined with MALDI-TOF MS, and subsequent analyses were performed on both WAT and BAT from 9-month-old male rats fed ad libitum or subjected to CR for 6 months. Our findings suggest that CR activates mitochondrial energy metabolism and fatty acid biosynthesis in WAT. It is likely that in CR animals WAT functions as an energy transducer from glucose to energy-dense lipid. In contrast, in BAT CR either had no effect on, or down-regulated, the mitochondrial electron transport chain, but enhanced fatty acid biosynthesis. This suggests that in CR animals BAT may change its function from an energy consuming system to an energy reservoir system. Based on our findings, we conclude that WAT and BAT cooperate to use energy effectively via a differential response of mitochondrial function to CR. PMID:22414572

  7. Effects of Obesity on Perivascular Adipose Tissue Vasorelaxant Function: Nitric Oxide, Inflammation and Elevated Systemic Blood Pressure

    PubMed Central

    Aghamohammadzadeh, Reza; Unwin, Richard D.; Greenstein, Adam S.; Heagerty, Anthony M.

    2016-01-01

    Introduction Perivascular adipose tissue (PVAT) surrounds most vessels in the human body. Healthy PVAT has a vasorelaxant effect which is not observed in obesity. We assessed the contribution of nitric oxide (NO), inflammation and endothelium to obesity-induced PVAT damage. Methods Rats were fed a high-fat diet or normal chow. PVAT function was assessed using wire myography. Skeletonised and PVAT-intact mesenteric vessels were prepared with and without endothelium. Vessels were incubated with L-NNA or superoxide dismutase (SOD) and catalase. Gluteal fat biopsies were performed on 10 obese and 10 control individuals, and adipose tissue was assessed using proteomic analysis. Results In the animals, there were significant correlations between weight and blood pressure (BP; r = 0.5, p = 0.02), weight and PVAT function (r = 0.51, p = 0.02), and PVAT function and BP (r = 0.53, p = 0.01). PVAT-intact vessel segments from healthy animals constricted significantly less than segments from obese animals (p < 0.05). In a healthy state, there was preservation of the PVAT vasorelaxant function after endothelium removal (p < 0.05). In endothelium-denuded vessels, L-NNA attenuated the PVAT vasorelaxant function in control vessels (p < 0.0001). In obesity, incubation with SOD and catalase attenuated PVAT-intact vessel contractility in the presence and absence of endothelium (p < 0.001). In obese humans, SOD [Cu-Zn] (SOD1; fold change −2.4), peroxiredoxin-1 (fold change −2.15) and adiponectin (fold change −2.1) were present in lower abundances than in healthy controls. Conclusions Incubation with SOD and catalase restores PVAT vasorelaxant function in animal obesity. In the rodent model, obesity-induced PVAT damage is independent of endothelium and is in part due to reduced NO bioavailability within PVAT. Loss of PVAT function correlates with rising BP in our animal obesity model. In keeping with our hypothesis of inflammation-induced damage to PVAT function in obesity, there

  8. 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. PMID:27125385

  9. Does Adipose Tissue Thermogenesis Play a Role in Metabolic Health?

    PubMed Central

    Porter, Craig; Børsheim, Elisabet; Sidossis, Labros S.

    2013-01-01

    The function ascribed to brown adipose tissue in humans has long been confined to thermoregulation in neonates, where this thermogenic capacity was thought lost with maturation. Recently, brown adipose tissue depots have been identified in adult humans. The significant oxidative capacity of brown adipocytes and the ability of their mitochondria to respire independently of ATP production, has led to renewed interest in the role that these adipocytes play in human energy metabolism. In our view, there is a need for robust physiological studies determining the relationship between molecular signatures of brown adipose tissue, adipose tissue mitochondrial function, and whole body energy metabolism, in order to elucidate the significance of thermogenic adipose tissue in humans. Until such information is available, the role of thermogenic adipose tissue in human metabolism and the potential that these adipocytes may prevent or treat obesity and metabolic diseases in humans will remain unknown. In this article, we summarize the recent literature pertaining to brown adipose tissue function with the aims of drawing the readers' attention to the lack of data concerning the role of brown adipocytes in human physiology, and to the potential limitations of current research strategies. PMID:23691283

  10. Epicardial adipose tissue and atrial fibrillation.

    PubMed

    Hatem, Stéphane N; Sanders, Prashanthan

    2014-05-01

    Atrial fibrillation (AF) is the most frequent cardiac arrhythmia in clinical practice. AF is often associated with profound functional and structural alterations of the atrial myocardium that compose its substrate. Recently, a relationship between the thickness of epicardial adipose tissue (EAT) and the incidence and severity of AF has been reported. Adipose tissue is a biologically active organ regulating the metabolism of neighbouring organs. It is also a major source of cytokines. In the heart, EAT is contiguous with the myocardium without fascia boundaries resulting in paracrine effects through the release of adipokines. Indeed, Activin A, which is produced in abundance by EAT during heart failure or diabetes, shows a marked fibrotic effect on the atrial myocardium. The infiltration of adipocytes into the atrial myocardium could also disorganize the depolarization wave front favouring micro re-entry circuits and local conduction block. Finally, EAT contains progenitor cells in abundance and therefore could be a source of myofibroblasts producing extracellular matrix. The study on the role played by adipose tissue in the pathogenesis of AF is just starting and is highly likely to uncover new biomarkers and therapeutic targets for AF. PMID:24648445

  11. Peptides from adipose tissue in mental disorders

    PubMed Central

    Wędrychowicz, Andrzej; Zając, Andrzej; Pilecki, Maciej; Kościelniak, Barbara; Tomasik, Przemysław J

    2014-01-01

    Adipose tissue is a dynamic endocrine organ that is essential to regulation of metabolism in humans. A new approach to mental disorders led to research on involvement of adipokines in the etiology of mental disorders and mood states and their impact on the health status of psychiatric patients, as well as the effects of treatment for mental health disorders on plasma levels of adipokines. There is evidence that disturbances in adipokine secretion are important in the pathogenesis, clinical presentation and outcome of mental disorders. Admittedly leptin and adiponectin are involved in pathophysiology of depression. A lot of disturbances in secretion and plasma levels of adipokines are observed in eating disorders with a significant impact on the symptoms and course of a disease. It is still a question whether observed dysregulation of adipokines secretion are primary or secondary. Moreover findings in this area are somewhat inconsistent, owing to differences in patient age, sex, socioeconomic status, smoking habits, level of physical activity, eating pathology, general health or medication. This was the rationale for our detailed investigation into the role of the endocrine functions of adipose tissue in mental disorders. It seems that we are continually at the beginning of understanding of the relation between adipose tissue and mental disorders. PMID:25540725

  12. Hepatocyte growth factor-modified adipose tissue-derived stem cells improve erectile function in streptozotocin-induced diabetic rats.

    PubMed

    Liu, Tao; Peng, Yifeng; Jia, Chao; Fang, Xiang; Li, Jing; Zhong, Wan

    2015-01-01

    TGFβ1-Smad signaling pathway is closely related to various tissues fibrosis. Hepatocyte growth factor (HGF) has been shown to antagonize TGFβ1-Smad signaling and may improve kidney tissue fibrosis in diabetic models. Penile fibrosis is a pathological condition which occurs during diabetic erectile dysfunction (ED). The aim of this study was to examine the effect of the treatment of ED in diabetic rats with a combination of HGF and adipose tissue-derived stem cells (ADSC). In this diabetes model, rats were injected intraperitoneally with 60 mg streptozotocin (STZ) to induce diabetes. Three months later, the diabetic rats were divided into a negative control(NC) group, an ADSC-treated group and an ADSC + HGF-treated group while normal rats were assigned into a sham group. Rats in the sham and NC groups were injected in the corpus cavernosum with phosphate-buffered saline, while rats in the other groups were injected with either ADSC or ADSC + HGF. One month later, erectile function was examined in each group and penile tissues were collected for experiments. The expression of smooth muscle actin (SMA) and platelet-endothelial cell adhesion molecule-1 (PECAM-1) was analyzed by Western blotting. The smooth muscle and collagen deposition in corpus cavernosum was evaluated by Masson staining, while endothelial changes were assessed immunohistochemically. Cell apoptosis was detected by the TdT-mediated dUTP nick-end labeling (TUNEL) assay. The results revealed that ADSC alone can significantly improve erectile function in diabetic rats, but in combination with HGF the improvement was more prominent, showing higher content of smooth muscle and endothelial cells and lower cell apoptotic index in corpus cavernosum. Treatment with HGF can significantly enhance the beneficial effect of ADSC on erectile function in diabetic rats, and this effect might be closely related to the down-regulation of TGFβ1-Smad signaling. PMID:26339935

  13. Adiponectin and Interleukin-6, But Not Adipose Tissue, Are Associated with Worse Neurocognitive Function in HIV-Infected Men

    PubMed Central

    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.

    2014-01-01

    Background 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. Methods 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 two 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. Results Of 509 HIV+ and 271 HIV− participants, HIV+ men (98% on ART, 81% HIV-1 RNA <50copies/mL) had lower median subcutaneous AT and adiponectin levels and higher hs-CRP levels, but visceral AT, BMI, 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. Conclusions 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. PMID:25810377

  14. 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

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

    PubMed

    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 tissues

  16. Proline oxidase–adipose triglyceride lipase pathway restrains adipose cell death and tissue inflammation

    PubMed Central

    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. PMID:24096872

  17. 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

  18. Role of adipose tissue in haemostasis, coagulation and fibrinolysis.

    PubMed

    Faber, D R; de Groot, Ph G; Visseren, F L J

    2009-09-01

    Obesity is associated with an increased incidence of insulin resistance (IR), type 2 diabetes mellitus and cardiovascular diseases. The increased risk for cardiovascular diseases could partly be caused by a prothrombotic state that exists because of abdominal obesity. Adipose tissue induces thrombocyte activation by the production of adipose tissue-derived hormones, often called adipokines, of which some such as leptin and adiponectin have been shown to directly interfere with platelet function. Increased adipose tissue mass induces IR and systemic low-grade inflammation, also affecting platelet function. It has been demonstrated that adipose tissue directly impairs fibrinolysis by the production of plasminogen activator inhibitor-1 and possibly thrombin-activatable fibrinolysis inhibitor. Adipose tissue may contribute to enhanced coagulation by direct tissue factor production, but hypercoagulability is likely to be primarily caused by affecting hepatic synthesis of the coagulation factors fibrinogen, factor VII, factor VIII and tissue factor, by releasing free fatty acids and pro-inflammatory cytokines (tumour necrosis factor-alpha, interleukin-1beta and interleukin-6) into the portal circulation and by inducing hepatic IR. Adipose tissue dysfunction could thus play a causal role in the prothrombotic state observed in obesity, by directly and indirectly affecting haemostasis, coagulation and fibrinolysis. PMID:19460118

  19. Animal Models for Adipose Tissue Engineering

    PubMed Central

    Uthamanthil, Rajesh; Beahm, Elisabeth; Frye, Cindy

    2008-01-01

    Abstract There is a critical need for adequate reconstruction of soft tissue defects resulting from tumor resection, trauma, and congenital abnormalities. To be sure, adipose tissue engineering strategies offer promising solutions. However, before clinical translation can occur, efficacy must be proven in animal studies. The aim of this review is to provide an overview of animal models currently employed for adipose tissue engineering. PMID:18544014

  20. Macrophage Migration Inhibitory Factor in Acute Adipose Tissue Inflammation.

    PubMed

    Kim, Bong-Sung; Rongisch, Robert; Hager, Stephan; Grieb, Gerrit; Nourbakhsh, Mahtab; Rennekampff, Hans-Oliver; Bucala, Richard; Bernhagen, Juergen; Pallua, Norbert

    2015-01-01

    Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine and has been implicated in inflammatory diseases. However, little is known about the regulation of MIF in adipose tissue and its impact on wound healing. The aim of this study was to investigate MIF expression in inflamed adipose and determine its role in inflammatory cell recruitment and wound healing. Adipose tissue was harvested from subcutaneous adipose tissue layers of 24 healthy subjects and from adipose tissue adjacent to acutely inflamed wounds of 21 patients undergoing wound debridement. MIF protein and mRNA expression were measured by ELISA and RT-PCR. Cell-specific MIF expression was visualized by immunohistochemistry. The functional role of MIF in cell recruitment was investigated by a chemotaxis assay and by flow cytometry of labeled macrophages that were injected into Mif-/-and wildtype mice. Wound healing was evaluated by an in vitro scratch assay on human fibroblast monolayers. MIF protein levels of native adipose tissue and supernatants from acutely inflamed wounds were significantly elevated when compared to healthy controls. MIF mRNA expression was increased in acutely inflamed adipose tissue indicating the activation of MIF gene transcription in response to adipose tissue inflammation. MIF is expressed in mature adipocytes and in infiltrated macrophages. Peripheral blood mononuclear cell migration was significantly increased towards supernatants derived from inflamed adipose tissue. This effect was partially abrogated by MIF-neutralizing antibodies. Moreover, when compared to wildtype mice, Mif-/-mice showed reduced infiltration of labeled macrophages into LPS-stimulated epididymal fat pads in vivo. Finally, MIF antibodies partially neutralized the detrimental effect of MIF on fibroblast wound healing. Our results indicate that increased MIF expression and rapid activation of the MIF gene in fat tissue adjacent to acute wound healing disorders may play a role in cell

  1. Macrophage Migration Inhibitory Factor in Acute Adipose Tissue Inflammation

    PubMed Central

    Kim, Bong-Sung; Rongisch, Robert; Hager, Stephan; Grieb, Gerrit; Nourbakhsh, Mahtab; Rennekampff, Hans-Oliver; Bucala, Richard; Bernhagen, Juergen; Pallua, Norbert

    2015-01-01

    Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine and has been implicated in inflammatory diseases. However, little is known about the regulation of MIF in adipose tissue and its impact on wound healing. The aim of this study was to investigate MIF expression in inflamed adipose and determine its role in inflammatory cell recruitment and wound healing. Adipose tissue was harvested from subcutaneous adipose tissue layers of 24 healthy subjects and from adipose tissue adjacent to acutely inflamed wounds of 21 patients undergoing wound debridement. MIF protein and mRNA expression were measured by ELISA and RT-PCR. Cell-specific MIF expression was visualized by immunohistochemistry. The functional role of MIF in cell recruitment was investigated by a chemotaxis assay and by flow cytometry of labeled macrophages that were injected into Mif–/–and wildtype mice. Wound healing was evaluated by an in vitro scratch assay on human fibroblast monolayers. MIF protein levels of native adipose tissue and supernatants from acutely inflamed wounds were significantly elevated when compared to healthy controls. MIF mRNA expression was increased in acutely inflamed adipose tissue indicating the activation of MIF gene transcription in response to adipose tissue inflammation. MIF is expressed in mature adipocytes and in infiltrated macrophages. Peripheral blood mononuclear cell migration was significantly increased towards supernatants derived from inflamed adipose tissue. This effect was partially abrogated by MIF-neutralizing antibodies. Moreover, when compared to wildtype mice, Mif–/–mice showed reduced infiltration of labeled macrophages into LPS-stimulated epididymal fat pads in vivo. Finally, MIF antibodies partially neutralized the detrimental effect of MIF on fibroblast wound healing. Our results indicate that increased MIF expression and rapid activation of the MIF gene in fat tissue adjacent to acute wound healing disorders may play a role in cell

  2. 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

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

    PubMed

    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

  4. Xenotransplantation of human fetal adipose tissue: a model of in vivo adipose tissue expansion and adipogenesis

    PubMed Central

    Garcia, Briana; Francois-Vaughan, Heather; Onikoyi, Omobola; Kostadinov, Stefan; De Paepe, Monique E.; Gruppuso, Philip A.; Sanders, Jennifer A.

    2014-01-01

    Obesity during childhood and beyond may have its origins during fetal or early postnatal life. At present, there are no suitable in vivo experimental models to study factors that modulate or perturb human fetal white adipose tissue (WAT) expansion, remodeling, development, adipogenesis, angiogenesis, or epigenetics. We have developed such a model. It involves the xenotransplantation of midgestation human WAT into the renal subcapsular space of immunocompromised SCID-beige mice. After an initial latency period of approximately 2 weeks, the tissue begins expanding. The xenografts are healthy and show robust expansion and angiogenesis for at least 2 months following transplantation. Data and cell size and gene expression are consistent with active angiogenesis. The xenografts maintain the expression of genes associated with differentiated adipocyte function. In contrast to the fetal tissue, adult human WAT does not engraft. The long-term viability and phenotypic maintenance of fetal adipose tissue following xenotransplantation may be a function of its autonomous high rates of adipogenesis and angiogenesis. Through the manipulation of the host mice, this model system offers the opportunity to study the mechanisms by which nutrients and other environmental factors affect human adipose tissue development and biology. PMID:25193996

  5. Xenotransplantation of human fetal adipose tissue: a model of in vivo adipose tissue expansion and adipogenesis.

    PubMed

    Garcia, Briana; Francois-Vaughan, Heather; Onikoyi, Omobola; Kostadinov, Stefan; De Paepe, Monique E; Gruppuso, Philip A; Sanders, Jennifer A

    2014-12-01

    Obesity during childhood and beyond may have its origins during fetal or early postnatal life. At present, there are no suitable in vivo experimental models to study factors that modulate or perturb human fetal white adipose tissue (WAT) expansion, remodeling, development, adipogenesis, angiogenesis, or epigenetics. We have developed such a model. It involves the xenotransplantation of midgestation human WAT into the renal subcapsular space of immunocompromised SCID-beige mice. After an initial latency period of approximately 2 weeks, the tissue begins expanding. The xenografts are healthy and show robust expansion and angiogenesis for at least 2 months following transplantation. Data and cell size and gene expression are consistent with active angiogenesis. The xenografts maintain the expression of genes associated with differentiated adipocyte function. In contrast to the fetal tissue, adult human WAT does not engraft. The long-term viability and phenotypic maintenance of fetal adipose tissue following xenotransplantation may be a function of its autonomous high rates of adipogenesis and angiogenesis. Through the manipulation of the host mice, this model system offers the opportunity to study the mechanisms by which nutrients and other environmental factors affect human adipose tissue development and biology. PMID:25193996

  6. 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. PMID:27411013

  7. More insights into a human adipose tissue GPAT activity assay

    PubMed Central

    Morgan-Bathke, Maria; Chen, Liang; Oberschneider, Elisabeth; Harteneck, Debra; Jensen, Michael D

    2016-01-01

    ABSTRACT Adipose tissue fatty acid storage varies according to sex, adipose tissue depot and degree of fat gain. However, the mechanism(s) for these variations is not completely understood. We recently published findings based on the glycerol 3-phosphate acyltransferase (GPAT) enzyme activity assay we optimized for use with human adipose tissue. These findings include a decrease in total GPAT and GPAT1 as a function of adipocyte size in both omental and subcutaneous adipose tissue and a strong, positive correlations between ACS, GPAT, and DGAT activities for both sexes and depots and between these storage factors and palmitate storage rates into TAG. The aim of this commentary is to expand upon the data from our recent publication. We describe here additional details on the optimization of the GPAT enzyme activity assay, a correlation between DGAT and percentage palmitate in the diacylglycerol fraction, and sex differences in fatty acid storage factors and storage rates into TAG at high palmitate concentrations. PMID:27144101

  8. 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

  9. 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

  10. 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

  11. Exercise and Adipose Tissue Macrophages: New Frontiers in Obesity Research?

    PubMed

    Goh, Jorming; Goh, Kian Peng; Abbasi, Asghar

    2016-01-01

    Obesity is a major public health problem in the twenty-first century. Mutations in genes that regulate substrate metabolism, subsequent dysfunction in their protein products, and other factors, such as increased adipose tissue inflammation, are some underlying etiologies of this disease. Increased inflammation in the adipose tissue microenvironment is partly mediated by the presence of cells from the innate and adaptive immune system. A subset of the innate immune population in adipose tissue include macrophages, termed adipose tissue macrophages (ATMs), which are central players in adipose tissue inflammation. Being extremely plastic, their responses to diverse molecular signals in the microenvironment dictate their identity and functional properties, where they become either pro-inflammatory (M1) or anti-inflammatory (M2). Endurance exercise training exerts global anti-inflammatory responses in multiple organs, including skeletal muscle, liver, and adipose tissue. The purpose of this review is to discuss the different mechanisms that drive ATM-mediated inflammation in obesity and present current evidence of how exercise training, specifically endurance exercise training, modulates the polarization of ATMs from an M1 to an M2 anti-inflammatory phenotype. PMID:27379017

  12. 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

  13. 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. PMID:27226402

  14. 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

  15. Maintenance of white adipose tissue in man.

    PubMed

    Hyvönen, Mervi T; Spalding, Kirsty L

    2014-11-01

    Obesity is increasing in an epidemic manner in most countries and constitutes a public health problem by enhancing the risk for diseases such as diabetes, fatty liver disease and atherosclerosis. Together these diseases form a cluster referred to as the metabolic syndrome. Despite the negative health consequences associated with excess adipose tissue, very little is known about the origin and maintenance of white adipose tissue in man. In this review we discuss what is known about the turnover of adult human adipocytes and their precursors, as well as adipose tissue heterogeneity, plasticity and developmental origins. The focus of this review is human tissue, however in many cases human data are missing and are inferred from animal studies. As such, reference to animal studies are made where human data is not available. This article is part of a directed issue entitled: Regenerative Medicine: the challenge of translation. PMID:25240584

  16. Tissue Engineering Chamber Promotes Adipose Tissue Regeneration in Adipose Tissue Engineering Models Through Induced Aseptic Inflammation

    PubMed Central

    Peng, Zhangsong; Dong, Ziqing; Chang, Qiang; Zhan, Weiqing; Zeng, Zhaowei; Zhang, Shengchang

    2014-01-01

    Tissue engineering chamber (TEC) makes it possible to generate significant amounts of mature, vascularized, stable, and transferable adipose tissue. However, little is known about the role of the chamber in tissue engineering. Therefore, to investigate the role of inflammatory response and the change in mechanotransduction started by TEC after implantation, we placed a unique TEC model on the surface of the groin fat pads in rats to study the expression of cytokines and tissue development in the TEC. The number of infiltrating cells was counted, and vascular endothelial growth factor (VEGF) and monocyte chemotactic protein-1 (MCP-1) expression levels in the chamber at multiple time points postimplantation were analyzed by enzyme-linked immunosorbent assay. Tissue samples were collected at various time points and labeled for specific cell populations. The result showed that new adipose tissue formed in the chamber at day 60. Also, the expression of MCP-1 and VEGF in the chamber decreased slightly from an early stage as well as the number of the infiltrating cells. A large number of CD34+/perilipin− perivascular cells could be detected at day 30. Also, the CD34+/perilipin+ adipose precursor cell numbers increased sharply by day 45 and then decreased by day 60. CD34−/perilipin+ mature adipocytes were hard to detect in the chamber content at day 30, but their number increased and then peaked at day 60. Ki67-positive cells could be found near blood vessels and their number decreased sharply over time. Masson's trichrome showed that collagen was the dominant component of the chamber content at early stage and was replaced by newly formed small adipocytes over time. Our findings suggested that the TEC implantation could promote the proliferation of adipose precursor cells derived from local adipose tissue, increase angiogenesis, and finally lead to spontaneous adipogenesis by inducing aseptic inflammation and changing local mechanotransduction. PMID:24559078

  17. 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. PMID:7631784

  18. SIRT1-mediated eNAMPT secretion from adipose tissue regulates hypothalamic NAD+ and function in mice

    PubMed Central

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

    2015-01-01

    SUMMARY 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 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. PMID:25921090

  19. 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. PMID:25695443

  20. Feast and famine: Adipose tissue adaptations for healthy aging.

    PubMed

    Lettieri Barbato, Daniele; Aquilano, Katia

    2016-07-01

    Proper adipose tissue function controls energy balance with favourable effects on metabolic health and longevity. The molecular and metabolic asset of adipose tissue quickly and dynamically readapts in response to nutrient fluctuations. Once delivered into cells, nutrients are managed by mitochondria that represent a key bioenergetics node. A persistent nutrient overload generates mitochondrial exhaustion and uncontrolled reactive oxygen species ((mt)ROS) production. In adipocytes, metabolic/molecular reorganization is triggered culminating in the acquirement of a hypertrophic and hypersecretory phenotype that accelerates aging. Conversely, dietary regimens such as caloric restriction or time-controlled fasting endorse mitochondrial functionality and (mt)ROS-mediated signalling, thus promoting geroprotection. In this perspective view, we argued some important molecular and metabolic aspects related to adipocyte response to nutrient stress. Finally we delineated hypothetical routes by which molecularly and metabolically readapted adipose tissue promotes healthy aging. PMID:27223996

  1. 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. PMID:27485231

  2. Injectable Biomaterials for Adipose Tissue Engineering

    PubMed Central

    Young, D. Adam; Christman, Karen L.

    2012-01-01

    Adipose tissue engineering has recently gained significant attention from materials scientists as a result of the exponential growth of soft tissue filler procedures being performed within the clinic. While several injectable materials are currently being marketed for filling subcutaneous voids, they often face limited longevity due to rapid resorption. Their inability to encourage natural adipose formation or ingrowth necessitates repeated injections for a prolonged effect, and thus classifies them as temporary fillers. As a result, a significant need for injectable materials that not only act as fillers, but also promote in vivo adipogenesis is beginning to be realized. This review will discuss the advantages and disadvantages of commercially available soft tissue fillers. It will then summarize the current state of research using injectable synthetic materials, biopolymers, and extracellular matrix-derived materials for adipose tissue engineering. Furthermore, the successful attributes observed across each of these materials will be outlined along with a discussion of the current difficulties and future directions for adipose tissue engineering. PMID:22456805

  3. Perivascular adipose tissue, vascular reactivity and hypertension.

    PubMed

    Oriowo, Mabayoje A

    2015-01-01

    Most blood vessels are surrounded by a variable amount of adventitial adipose tissue, perivascular adipose tissue (PVAT), which was originally thought to provide mechanical support for the vessel. It is now known that PVAT secretes a number of bioactive substances including vascular endothelial growth factor, tumor necrosis factor-alpha (TNF-α), leptin, adiponectin, insulin-like growth factor, interleukin-6, plasminogen activator substance, resistin and angiotensinogen. Several studies have shown that PVAT significantly modulated vascular smooth muscle contractions induced by a variety of agonists and electrical stimulation by releasing adipocyte-derived relaxing (ADRF) and contracting factors. The identity of ADRF is not yet known. However, several vasodilators have been suggested including adiponectin, angiotensin 1-7, hydrogen sulfide and methyl palmitate. The anticontractile effect of PVAT is mediated through the activation of potassium channels since it is abrogated by inhibiting potassium channels. Hypertension is characterized by a reduction in the size and amount of PVAT and this is associated with the attenuated anticontractile effect of PVAT in hypertension. However, since a reduction in size and amount of PVAT and the attenuated anticontractile effect of PVAT were already evident in prehypertensive rats with no evidence of impaired release of ADRF, there is the possibility that the anticontractile effect of PVAT was not directly related to an altered function of the adipocytes per se. Hypertension is characterized by low-grade inflammation and infiltration of macrophages. One of the adipokines secreted by macrophages is TNF-α. It has been shown that exogenously administered TNF-α enhanced agonist-induced contraction of a variety of vascular smooth muscle preparations and reduced endothelium-dependent relaxation. Other procontractile factors released by the PVAT include angiotensin II and superoxide. It is therefore possible that the loss could be due

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

    PubMed

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

    2016-08-01

    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. PMID:27246738

  5. 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

  6. Prohibitin in Adipose and Immune Functions.

    PubMed

    Ande, Sudharsana R; Nguyen, K Hoa; Nyomba, B L Grégoire; Mishra, Suresh

    2016-08-01

    Prohibitin (PHB) was discovered in a quest to find genes with antiproliferative functions. However, the attribute of PHB that is responsible for its antiproliferative function remains elusive. Meanwhile, recent studies have established PHB as a pleiotropic protein with roles in metabolism, immunity, and senescence. PHB has cell compartment-specific functions, acting as a scaffolding protein in mitochondria, an adaptor molecule in membrane signaling, and a transcriptional coregulator in the nucleus. However, it remains unclear whether different functions and locations of PHB are interrelated or independent from each other, or if PHB works in a tissue-specific manner. Here, we discuss new findings on the role of PHB in adipose-immune interaction and an unexpected role in sex differences in adipose and immune functions. PMID:27312736

  7. 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

  8. Enzymatic intracrine regulation of white adipose tissue.

    PubMed

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

    2014-07-01

    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

  9. 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

  10. 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. PMID:27112904

  11. 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.

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

    PubMed

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

    2016-08-01

    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

  13. 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

  14. Id transcriptional regulators in adipogenesis and adipose tissue metabolism

    PubMed Central

    Patil, Mallikarjun; Sharma, Bal Krishan; Satyanarayana, Ande

    2014-01-01

    Id proteins (Id1-Id4) are helix-loop-helix (HLH) transcriptional regulators that lack a basic DNA binding domain. They act as negative regulators of basic helixloop-helix (bHLH) transcription factors by forming heterodimers and inhibit their DNA binding and transcriptional activity. Id proteins are implicated in the regulation of various cellular mechanisms such as cell proliferation, cellular differentiation, cell fate determination, angiogenesis and tumorigenesis. A handful of recent studies also disclosed that Id proteins have critical functions in adipocyte differentiation and adipose tissue metabolism. Here, we reviewed the progress made thus far in understanding the specific functions of Id proteins in adipose tissue differentiation and metabolism. In addition to reviewing the known mechanisms of action, we also discuss possible additional mechanisms in which Id proteins might participate in regulating adipogenic and metabolic pathways. PMID:24896358

  15. Mechanisms of perivascular adipose tissue dysfunction in obesity.

    PubMed

    Fernández-Alfonso, Maria S; Gil-Ortega, Marta; García-Prieto, Concha F; Aranguez, Isabel; Ruiz-Gayo, Mariano; Somoza, Beatriz

    2013-01-01

    Most blood vessels are surrounded by adipose tissue. Similarly to the adventitia, perivascular adipose tissue (PVAT) was considered only as a passive structural support for the vasculature, and it was routinely removed for isolated blood vessel studies. In 1991, Soltis and Cassis demonstrated for the first time that PVAT reduced contractions to noradrenaline in rat aorta. Since then, an important number of adipocyte-derived factors with physiological and pathophysiological paracrine vasoactive effects have been identified. PVAT undergoes structural and functional changes in obesity. During early diet-induced obesity, an adaptative overproduction of vasodilator factors occurs in PVAT, probably aimed at protecting vascular function. However, in established obesity, PVAT loses its anticontractile properties by an increase of contractile, oxidative, and inflammatory factors, leading to endothelial dysfunction and vascular disease. The aim of this review is to focus on PVAT dysfunction mechanisms in obesity. PMID:24307898

  16. Mechanisms of Perivascular Adipose Tissue Dysfunction in Obesity

    PubMed Central

    Fernández-Alfonso, Maria S.; García-Prieto, Concha F.; Aranguez, Isabel; Ruiz-Gayo, Mariano; Somoza, Beatriz

    2013-01-01

    Most blood vessels are surrounded by adipose tissue. Similarly to the adventitia, perivascular adipose tissue (PVAT) was considered only as a passive structural support for the vasculature, and it was routinely removed for isolated blood vessel studies. In 1991, Soltis and Cassis demonstrated for the first time that PVAT reduced contractions to noradrenaline in rat aorta. Since then, an important number of adipocyte-derived factors with physiological and pathophysiological paracrine vasoactive effects have been identified. PVAT undergoes structural and functional changes in obesity. During early diet-induced obesity, an adaptative overproduction of vasodilator factors occurs in PVAT, probably aimed at protecting vascular function. However, in established obesity, PVAT loses its anticontractile properties by an increase of contractile, oxidative, and inflammatory factors, leading to endothelial dysfunction and vascular disease. The aim of this review is to focus on PVAT dysfunction mechanisms in obesity. PMID:24307898

  17. 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

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

    2009-01-01

    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

  18. Adipose tissue as a medium for epidemiologic exposure assessment.

    PubMed Central

    Kohlmeier, L; Kohlmeier, M

    1995-01-01

    In the United States, adipose tissue is rarely used as a medium for assessment of prior exposures in epidemiologic studies. Adipose tissue aspirations are in general less invasive and carry less risk than phlebotomy. Tissue samples can be analyzed for a wide number of epidemiologically important exposures. Beyond reflecting long-term energy balance, this tissue offers a relatively stable depot of triglyceride and fat-soluble substances, such as fat-soluble vitamins, and pesticides. As a tissue it represents the greatest reservoir of carotenoids in the body. Halogenated hydrocarbons may be measured in concentrations of hundreds-fold greater than those in blood of the same individuals. The composition of adipose tissue also reflects the long-term dietary intakes of a number of essential fatty acids. The turnover times of all of these substances in adipose tissue remain under-researched. Sampling and storage of adipose tissue, homogeneity of sampling sites, turnover times, and the effects of diet, age, gender, race, hormones, and disease on adipose tissue composition are discussed in this review of current knowledge about adipose tissue stability. Experience in the use of adipose tissue sampling in epidemiologic studies in various countries has shown that it is simple to conduct, requires little training, carries little risk, and does not result in excessive participant refusal. PMID:7635122

  19. C/EBPβ, When Expressed from the C/ebpα Gene Locus, Can Functionally Replace C/EBPα in Liver but Not in Adipose Tissue

    PubMed Central

    Chen, Shih-Shun; Chen, Jin-Feng; Johnson, Peter F.; Muppala, Vijayakumar; Lee, Ying-Hue

    2000-01-01

    Knockout of C/EBPα causes a severe loss of liver function and, subsequently, neonatal lethality in mice. By using a gene replacement approach, we generated a new C/EBPα-null mouse strain in which C/EBPβ, in addition to its own expression, substituted for C/EBPα expression in tissues. The homozygous mutant mice C/ebpαβ/β are viable and fertile and show none of the overt liver abnormalities found in the previous C/EBPα-null mouse line. Levels of hepatic PEPCK mRNA are not different between C/ebpαβ/β and wild-type mice. However, despite their normal growth rate, C/ebpαβ/β mice have markedly reduced fat storage in their white adipose tissue (WAT). Expression of two adipocyte-specific factors, adipsin and leptin, is significantly reduced in the WAT of C/ebpαβ/β mice. In addition, expression of the non-adipocyte-specific genes for transferrin and cysteine dioxygenase is reduced in WAT but not in liver. Our study demonstrates that when expressed from the C/ebpα gene locus, C/EBPβ can act for C/EBPα to maintain liver functions during development. Moreover, our studies with the C/ebpαβ/β mice provide new insights into the nonredundant functions of C/EBPα and C/EBPβ on gene regulation in WAT. PMID:10982846

  20. Adiposity-Dependent Regulatory Effects on Multi-tissue Transcriptomes.

    PubMed

    Glastonbury, Craig A; Viñuela, Ana; Buil, Alfonso; Halldorsson, Gisli H; Thorleifsson, Gudmar; Helgason, Hannes; Thorsteinsdottir, Unnur; Stefansson, Kari; Dermitzakis, Emmanouil T; Spector, Tim D; Small, Kerrin S

    2016-09-01

    Obesity is a global epidemic that is causally associated with a range of diseases, including type 2 diabetes and cardiovascular disease, at the population-level. However, there is marked heterogeneity in obesity-related outcomes among individuals. This might reflect genotype-dependent responses to adiposity. Given that adiposity, measured by BMI, is associated with widespread changes in gene expression and regulatory variants mediate the majority of known complex trait loci, we sought to identify gene-by-BMI (G × BMI) interactions on the regulation of gene expression in a multi-tissue RNA-sequencing (RNA-seq) dataset from the TwinsUK cohort (n = 856). At a false discovery rate of 5%, we identified 16 cis G × BMI interactions (top cis interaction: CHURC1, rs7143432, p = 2.0 × 10(-12)) and one variant regulating 53 genes in trans (top trans interaction: ZNF423, rs3851570, p = 8.2 × 10(-13)), all in adipose tissue. The interactions were adipose-specific and enriched for variants overlapping adipocyte enhancers, and regulated genes were enriched for metabolic and inflammatory processes. We replicated a subset of the interactions in an independent adipose RNA-seq dataset (deCODE genetics, n = 754). We also confirmed the interactions with an alternate measure of obesity, dual-energy X-ray absorptiometry (DXA)-derived visceral-fat-volume measurements, in a subset of TwinsUK individuals (n = 682). The identified G × BMI regulatory effects demonstrate the dynamic nature of gene regulation and reveal a functional mechanism underlying the heterogeneous response to obesity. Additionally, we have provided a web browser allowing interactive exploration of the dataset, including of association between expression, BMI, and G × BMI regulatory effects in four tissues. PMID:27588447

  1. 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

  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. Macrophage Elastase Suppresses White Adipose Tissue Expansion with Cigarette Smoking

    PubMed Central

    Tsuji, Takao; Kelly, Neil J.; Takahashi, Saeko; Leme, Adriana S.; McGarry Houghton, A.

    2014-01-01

    Macrophage elastase (MMP12) is a key mediator of cigarette smoke (CS)-induced emphysema, yet its role in other smoking related pathologies remains unclear. The weight suppressing effects of smoking are a major hindrance to cessation efforts, and MMP12 is known to suppress the vascularization on which adipose tissue growth depends by catalyzing the formation of antiangiogenic peptides endostatin and angiostatin. The goal of this study was to determine the role of MMP12 in adipose tissue growth and smoking-related suppression of weight gain. Whole body weights and white adipose depots from wild-type and Mmp12-deficient mice were collected during early postnatal development and after chronic CS exposure. Adipose tissue specimens were analyzed for angiogenic and adipocytic markers and for content of the antiangiogenic peptides endostatin and angiostatin. Cultured 3T3-L1 adipocytes were treated with adipose tissue homogenate to examine its effects on vascular endothelial growth factor (VEGF) expression and secretion. MMP12 content and activity were increased in the adipose tissue of wild-type mice at 2 weeks of age, leading to elevated endostatin production, inhibition of VEGF secretion, and decreased adipose tissue vascularity. By 8 weeks of age, adipose MMP12 levels subsided, and the protein was no longer detectable. However, chronic CS exposure led to macrophage accumulation and restored adipose MMP12 activity, thereby suppressing adipose tissue mass and vascularity. Our results reveal a novel systemic role for MMP12 in postnatal adipose tissue expansion and smoking-associated weight loss by suppressing vascularity within the white adipose tissue depots. PMID:24914890

  4. Elevated autophagy gene expression in adipose tissue of obese humans: A potential non-cell-cycle-dependent function of E2F1

    PubMed Central

    Haim, Yulia; Blüher, Matthias; Slutsky, Noa; Goldstein, Nir; Klöting, Nora; Harman-Boehm, Ilana; Kirshtein, Boris; Ginsberg, Doron; Gericke, Martin; Guiu Jurado, Esther; Kovsan, Julia; Tarnovscki, Tanya; Kachko, Leonid; Bashan, Nava; Gepner, Yiftach; Shai, Iris; Rudich, Assaf

    2015-01-01

    Autophagy genes' expression is upregulated in visceral fat in human obesity, associating with obesity-related cardio-metabolic risk. E2F1 (E2F transcription factor 1) was shown in cancer cells to transcriptionally regulate autophagy. We hypothesize that E2F1 regulates adipocyte autophagy in obesity, associating with endocrine/metabolic dysfunction, thereby, representing non-cell-cycle function of this transcription factor. E2F1 protein (N=69) and mRNA (N=437) were elevated in visceral fat of obese humans, correlating with increased expression of ATG5 (autophagy-related 5), MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3 β), but not with proliferation/cell-cycle markers. Elevated E2F1 mainly characterized the adipocyte fraction, whereas MKI67 (marker of proliferation Ki-67) was elevated in the stromal-vascular fraction of adipose tissue. In human visceral fat explants, chromatin-immunoprecipitation revealed body mass index (BMI)-correlated increase in E2F1 binding to the promoter of MAP1LC3B, but not to the classical cell cycle E2F1 target, CCND1 (cyclin D1). Clinically, omental fat E2F1 expression correlated with insulin resistance, circulating free-fatty-acids (FFA), and with decreased circulating ADIPOQ/adiponectin, associations attenuated by adjustment for autophagy genes. Overexpression of E2F1 in HEK293 cells enhanced promoter activity of several autophagy genes and autophagic flux, and sensitized to further activation of autophagy by TNF. Conversely, mouse embryonic fibroblast (MEF)-derived adipocytes from e2f1 knockout mice (e2f1−/−) exhibited lower autophagy gene expression and flux, were more insulin sensitive, and secreted more ADIPOQ. Furthermore, e2f1−/− MEF-derived adipocytes, and autophagy-deficient (by Atg7 siRNA) adipocytes were resistant to cytokines-induced decrease in ADIPOQ secretion. Jointly, upregulated E2F1 sensitizes adipose tissue autophagy to inflammatory stimuli, linking visceral obesity to adipose and systemic

  5. Orexin receptor expression in human adipose tissue: effects of orexin-A and orexin-B.

    PubMed

    Digby, J E; Chen, J; Tang, J Y; Lehnert, H; Matthews, R N; Randeva, H S

    2006-10-01

    Orexin-A and orexin-B, via their receptors orexin-1 receptor (OX1R) and orexin-2 receptor (OX2R) have been shown to play a role in the regulation of feeding, body weight, and energy expenditure. Adipose tissue also contributes significantly to the maintenance of body weight by interacting with a complex array of bioactive peptides; however, there are no data as yet on the expression of orexin components in adipose tissue. We, therefore, analyzed the expression of OX1R and OX2R in human adipose tissue and determined functional responses to orexin-A and orexin-B. OX1R and OX2R mRNA expression was detected in subcutaneous (s.c.) and omental adipose tissue and in isolated adipocytes. Protein for OX1R and OX2R was also detected in whole adipose tissue sections and lysates. Treatment with orexin-A, and orexin-B (100 nM, 24 h) resulted in a significant increase in peroxisome proliferator-activated receptors gamma-2 mRNA expression in s.c. adipose tissue (P < 0.05). Hormone sensitive lipase mRNA was significantly reduced in omental adipose tissue with orexin-A and orexin-B treatment (P < 0.05). Glycerol release from omental adipose tissue was also significantly reduced with orexin-A treatment (P < 0.05). These findings demonstrate for the first time the presence of functional orexin receptors in human adipose tissue and suggest a role for orexins in adipose tissue metabolism and adipogenesis. PMID:17065396

  6. 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

    2016-02-01

    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. PMID:26767403

  7. Delayed Intervention With Pyridoxamine Improves Metabolic Function and Prevents Adipose Tissue Inflammation and Insulin Resistance in High-Fat Diet-Induced Obese Mice.

    PubMed

    Maessen, Dionne E; Brouwers, Olaf; Gaens, Katrien H; Wouters, Kristiaan; Cleutjens, Jack P; Janssen, Ben J; Miyata, Toshio; Stehouwer, Coen D; Schalkwijk, Casper G

    2016-04-01

    Obesity is associated with an increased risk for the development of type 2 diabetes and vascular complications. Advanced glycation end products are increased in adipose tissue and have been associated with insulin resistance, vascular dysfunction, and inflammation of adipose tissue. Here, we report that delayed intervention with pyridoxamine (PM), a vitamin B6 analog that has been identified as an antiglycating agent, protected against high-fat diet (HFD)-induced body weight gain, hyperglycemia, and hypercholesterolemia, compared with mice that were not treated. In both HFD-induced and db/db obese mice, impaired glucose metabolism and insulin resistance were prevented by PM supplementation. PM inhibited the expansion of adipose tissue and adipocyte hypertrophy in mice. In addition, adipogenesis of murine 3T3-L1 and human Simpson-Golabi-Behmel Syndrome preadipocytes was dose- and time-dependently reduced by PM, as demonstrated by Oil Red O staining and reduced expression of adipogenic differentiation genes. No ectopic fat deposition was found in the liver of HFD mice. The high expression of proinflammatory genes in visceral adipose tissue of the HFD group was significantly attenuated by PM. Treatment with PM partially prevented HFD-induced mild vascular dysfunction. Altogether, these findings highlight the potential of PM to serve as an intervention strategy in obesity. PMID:26718500

  8. Mechanoresponsive musculoskeletal tissue differentiation of adipose-derived stem cells.

    PubMed

    Trumbull, Andrew; Subramanian, Gayathri; Yildirim-Ayan, Eda

    2016-01-01

    Musculoskeletal tissues are constantly under mechanical strains within their microenvironment. Yet, little is understood about the effect of in vivo mechanical milieu strains on cell development and function. Thus, this review article outlines the in vivo mechanical environment of bone, muscle, cartilage, tendon, and ligaments, and tabulates the mechanical strain and stress in these tissues during physiological condition, vigorous, and moderate activities. This review article further discusses the principles of mechanical loading platforms to create physiologically relevant mechanical milieu in vitro for musculoskeletal tissue regeneration. A special emphasis is placed on adipose-derived stem cells (ADSCs) as an emerging valuable tool for regenerative musculoskeletal tissue engineering, as they are easily isolated, expanded, and able to differentiate into any musculoskeletal tissue. Finally, it highlights the current state-of-the art in ADSCs-guided musculoskeletal tissue regeneration under mechanical loading. PMID:27103394

  9. Neurotrophic Effect of Adipose Tissue-Derived Stem Cells on Erectile Function Recovery by Pigment Epithelium-Derived Factor Secretion in a Rat Model of Cavernous Nerve Injury

    PubMed Central

    Chen, Xin; Yang, Qiyun; Zheng, Tao; Bian, Jun; Sun, Xiangzhou; Shi, Yanan; Liang, Xiaoyan; Gao, Guoquan; Liu, Guihua; Deng, Chunhua

    2016-01-01

    The paracrine effect is the major mechanism of stem cell therapy. However, the details of the effect's mechanism remain unknown. The aim of this study is to investigate whether adipose tissue-derived stem cells (ADSCs) can ameliorate cavernous nerve injury-induced erectile dysfunction (CNIED) rats and to determine its mechanism. Twenty-eight days after intracavernous injection of 5-ethynyl-2-deoxyuridine- (EdU-) labeled ADSCs, the erectile function of all the rats was evaluated by intracavernosal pressure (ICP). The ADSCs steadily secreted detectable pigment epithelium-derived factor (PEDF) in vitro. The expression of PEDF increased in the penis of the bilateral cavernous nerve injury (BCNI) group for 14 days and then gradually decreased. On day 28 after the intracavernous injection, the ADSCs group exhibited a significantly increased ICP compared with the phosphate buffered saline- (PBS-) treated group. Moreover, the neuronal nitric oxide synthase (nNOS) and S100 expression in penile dorsal nerves and the smooth muscle content to collagen ratio in penile tissues significantly increased. Furthermore, elevated PEDF, p-Akt, and p-eNOS were identified in the ADSCs group. This study demonstrated that intracavernous injection of ADSCs improved erectile function, repaired the nerve, and corrected penile fibrosis. One potential mechanism is the PEDF secretion of ADSCs and subsequent PI3K/Akt pathway activation. PMID:26783403

  10. 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

  11. Identification of progesterone receptor in human subcutaneous adipose tissue.

    PubMed

    O'Brien, S N; Welter, B H; Mantzke, K A; Price, T M

    1998-02-01

    Sex steroids are postulated to play a role in adipose tissue regulation and distribution, because the amount and location of adipose tissue changes during puberty and menopause. Because of the nature of adipose tissue, receptors for the female sex steroids have been difficult to demonstrate. To date, estrogen receptor messenger RNA and protein have been identified in human subcutaneous adipose tissue, but the presence of progesterone receptor (PR) has not been reported. In this study, we demonstrate PR message by Northern blot analysis in RNA isolated from the abdominal subcutaneous adipose tissue of premenopausal women. These preliminary studies revealed that PR messenger RNA levels are higher in the stromal-vascular fraction as opposed to the adipocyte fraction. Western blot analysis demonstrates both PR protein isoforms (human PR-A and human PR-B) in human subcutaneous adipose tissue. Using an enzyme-linked immunosorbent assay, total PR could be quantitated. These studies substantiate that sex steroid receptors are present in human adipose tissue, thereby providing a direct route for regulation of adipose tissue by female sex steroids. PMID:9467566

  12. Altered autophagy in human adipose tissues in obesity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  13. Adipose tissue and the reproductive axis: biological aspects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  14. Ontogeny of adipokine expression in neonatal pig adipose tissue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study examined ontogeny of development for a range of adipokines in neonatal adipose tissue. Pigs were selected across six litters for sampling at d1, d4, d7 or d21 of age. Subcutaneous (SQ) and perirenal (PR) adipose tissue were collected and extracted for total RNA. SQ was also collected f...

  15. Albumin induced cytokine expression in porcine adipose tissue explants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  17. 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. PMID:16567517

  18. Immune response in the adipose tissue of lean mice infected with the protozoan parasite Neospora caninum

    PubMed Central

    Teixeira, Luzia; Moreira, João; Melo, Joana; Bezerra, Filipa; Marques, Raquel M; Ferreirinha, Pedro; Correia, Alexandra; Monteiro, Mariana P; Ferreira, Paula G; Vilanova, Manuel

    2015-01-01

    The adipose tissue can make important contributions to immune function. Nevertheless, only a limited number of reports have investigated in lean hosts the immune response elicited in this tissue upon infection. Previous studies suggested that the intracellular protozoan Neospora caninum might affect adipose tissue physiology. Therefore, we investigated in mice challenged with this protozoan if immune cell populations within adipose tissue of different anatomical locations could be differently affected. Early in infection, parasites were detected in the adipose tissue and by 7 days of infection increased numbers of macrophages, regulatory T (Treg) cells and T-bet+ cells were observed in gonadal, mesenteric, omental and subcutaneous adipose tissue. Increased expression of interferon-γ was also detected in gonadal adipose tissue of infected mice. Two months after infection, parasite DNA was no longer detected in these tissues, but T helper type 1 (Th1) cell numbers remained above control levels in the infected mice. Moreover, the Th1/Treg cell ratio was higher than that of controls in the mesenteric and subcutaneous adipose tissue. Interestingly, chronically infected mice presented a marked increase of serum leptin, a molecule that plays a role in energy balance regulation as well as in promoting Th1-type immune responses. Altogether, we show that an apicomplexa parasitic infection influences immune cellular composition of adipose tissue throughout the body as well as adipokine production, still noticed at a chronic phase of infection when parasites were already cleared from that particular tissue. This strengthens the emerging view that infections can have long-term consequences for the physiology of adipose tissue. PMID:25581844

  19. Surgical injury induces local and distant adipose tissue browning.

    PubMed

    Longchamp, Alban; Tao, Ming; Bartelt, Alexander; Ding, Kui; Lynch, Lydia; Hine, Christopher; Corpataux, Jean-Marc; Kristal, Bruce S; Mitchell, James R; Ozaki, C Keith

    2016-01-01

    The adipose organ, which comprises brown, white and beige adipocytes, possesses remarkable plasticity in response to feeding and cold exposure. The development of beige adipocytes in white adipose tissue (WAT), a process called browning, represents a promising route to treat metabolic disorders. While surgical procedures constantly traumatize adipose tissue, its impact on adipocyte phenotype remains to be established. Herein, we studied the effect of trauma on adipocyte phenotype one day after sham, incision control, or surgical injury to the left inguinal adipose compartment. Caloric restriction was used to control for surgery-associated body temperature changes and weight loss. We characterized the trauma-induced cellular and molecular changes in subcutaneous, visceral, interscapular, and perivascular adipose tissue using histology, immunohistochemistry, gene expression, and flow cytometry analysis. After one day, surgical trauma stimulated adipose tissue browning at the site of injury and, importantly, in the contralateral inguinal depot. Browning was not present after incision only, and was largely independent of surgery-associated body temperature and weight loss. Adipose trauma rapidly recruited monocytes to the injured site and promoted alternatively activated macrophages. Conversely, PDGF receptor-positive beige progenitors were reduced. In this study, we identify adipose trauma as an unexpected driver of selected local and remote adipose tissue browning, holding important implications for the biologic response to surgical injury. PMID:27386152

  20. 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

  1. Comparison of human adipose-derived stem cells isolated from subcutaneous, omental, and intrathoracic adipose tissue depots for regenerative applications.

    PubMed

    Russo, Valerio; Yu, Claire; Belliveau, Paul; Hamilton, Andrew; Flynn, Lauren E

    2014-02-01

    Adipose tissue is an abundant source of multipotent progenitor cells that have shown promise in regenerative medicine. In humans, fat is primarily distributed in the subcutaneous and visceral depots, which have varying biochemical and functional properties. In most studies to date, subcutaneous adipose tissue has been investigated as the adipose-derived stem cell (ASC) source. In this study, we sought to develop a broader understanding of the influence of specific adipose tissue depots on the isolated ASC populations through a systematic comparison of donor-matched abdominal subcutaneous fat and omentum, and donor-matched pericardial adipose tissue and thymic remnant samples. We found depot-dependent and donor-dependent variability in the yield, viability, immunophenotype, clonogenic potential, doubling time, and adipogenic and osteogenic differentiation capacities of the ASC populations. More specifically, ASCs isolated from both intrathoracic depots had a longer average doubling time and a significantly higher proportion of CD34(+) cells at passage 2, as compared with cells isolated from subcutaneous fat or the omentum. Furthermore, ASCs from subcutaneous and pericardial adipose tissue demonstrated enhanced adipogenic differentiation capacity, whereas ASCs isolated from the omentum displayed the highest levels of osteogenic markers in culture. Through cell culture analysis under hypoxic (5% O(2)) conditions, oxygen tension was shown to be a key mediator of colony-forming unit-fibroblast number and osteogenesis for all depots. Overall, our results suggest that depot selection is an important factor to consider when applying ASCs in tissue-specific cell-based regenerative therapies, and also highlight pericardial adipose tissue as a potential new ASC source. PMID:24361924

  2. 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. PMID:26076904

  3. 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. PMID:26124828

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

    PubMed Central

    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. PMID:26124828

  5. Adipose-derived stem cells: Implications in tissue regeneration

    PubMed Central

    Tsuji, Wakako; Rubin, J Peter; Marra, Kacey G

    2014-01-01

    Adipose-derived stem cells (ASCs) are mesenchymal stem cells (MSCs) that are obtained from abundant adipose tissue, adherent on plastic culture flasks, can be expanded in vitro, and have the capacity to differentiate into multiple cell lineages. Unlike bone marrow-derived MSCs, ASCs can be obtained from abundant adipose tissue by a minimally invasive procedure, which results in a high number of cells. Therefore, ASCs are promising for regenerating tissues and organs damaged by injury and diseases. This article reviews the implications of ASCs in tissue regeneration. PMID:25126381

  6. Adipose tissue and ceramide biosynthesis in the pathogenesis of obesity.

    PubMed

    Samad, Fahumiya; Badeanlou, Leylla; Shah, Charmi; Yang, Guang

    2011-01-01

    Although obesity is a complex metabolic disorder often associated with insulin resistance, hyperinsulinemia and Type 2 diabetes, as well as with accelerated atherosclerosis, the molecular changes in obesity that promote these disorders are not completely understood. Several mechanisms have been proposed to explain how increased adipose tissue mass affects whole body insulin resistance and cardiovascular risk. One theory is that increased adipose derived inflammatory cytokines induces a chronic inflammatory state that not only increases cardiovascular risk, but also antagonizes insulin signaling and mitochondrial function and thereby impair glucose hemostasis. Another suggests that lipid accumulation in nonadipose tissues not suited for fat storage leads to the buildup of bioactive lipids that inhibit insulin signaling and metabolism. Recent evidence demonstrates that sphingolipid metabolism is dysregulated in obesity and specific sphingolipids may provide a common pathway that link excess nutrients and inflammation to increased metabolic and cardiovascular risk. This chapter will focus primarily on the expression and regulation of adipose and plasma ceramide biosynthesis in obesity and, its potential contribution to the pathogenesis of obesity and the metabolic syndrome. PMID:21910083

  7. 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

  8. 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.

  9. Obesity-Induced Changes in Adipose Tissue Microenvironment and Their Impact on Cardiovascular Disease.

    PubMed

    Fuster, José J; Ouchi, Noriyuki; Gokce, Noyan; Walsh, Kenneth

    2016-05-27

    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 proinflammatory 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

  10. Adipose Tissue and Adrenal Glands: Novel Pathophysiological Mechanisms and Clinical Applications

    PubMed Central

    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. PMID:25018768

  11. High-fat diet feeding induces a depot-dependent response on the pro-inflammatory state and mitochondrial function of gonadal white adipose tissue.

    PubMed

    Amengual-Cladera, E; Lladó, I; Proenza, A M; Gianotti, M

    2013-02-14

    Obesity has been related to a chronic pro-inflammatory state affecting white adipose tissue (WAT), which has a great impact on carbohydrate, lipid and energy metabolism. In turn, the dysregulation of adipokine secretion derived from the accumulation of excess lipids in adipocytes further contributes to the development of insulin resistance and can be associated with mitochondrial dysfunction. The aim of the present study was to determine whether sexual dimorphism found in the systemic insulin sensitivity profile is related to sex differences in a high-fat diet (HFD) response of gonadal WAT at mitochondrial function and inflammatory profile levels. Wistar rats (10 weeks old) of both sexes were fed a control pelleted diet (3 % (w/w) fat; n 8 for each sex) or a HFD (24 % (w/w) fat; n 8 for each sex). Serum insulin sensitivity markers, mRNA expression levels of inflammatory factors and the protein content of insulin and adiponectin signalling pathways were analysed, as well as the levels of the main markers of mitochondrial biogenesis, antioxidant defence and oxidative damage. In the present study, the periovarian depot exhibits a greater expandability capacity, along with a lower hypoxic and pro-inflammatory state, without signs of mitochondrial dysfunction or changes in its dynamics. In contrast, epididymal fat has a much more pronounced pro-inflammatory, hypoxic and insulin-resistant profile accompanied by changes in mitochondrial dynamics, probably associated with HFD-induced mitochondrial dysfunction. Thus, this explains the worse serum insulin sensitivity profile of male rats. PMID:22717037

  12. 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. PMID:27325693

  13. Activation of prostaglandin E2-EP4 signaling reduces chemokine production in adipose tissue.

    PubMed

    Tang, Eva H C; Cai, Yin; Wong, Chi Kin; Rocha, Viviane Z; Sukhova, Galina K; Shimizu, Koichi; Xuan, Ge; Vanhoutte, Paul M; Libby, Peter; Xu, Aimin

    2015-02-01

    Inflammation of adipose tissue induces metabolic derangements associated with obesity. Thus, determining ways to control or inhibit inflammation in adipose tissue is of clinical interest. The present study tested the hypothesis that in mouse adipose tissue, endogenous prostaglandin E2 (PGE2) negatively regulates inflammation via activation of prostaglandin E receptor 4 (EP4). PGE2 (5-500 nM) attenuated lipopolysaccharide-induced mRNA and protein expression of chemokines, including interferon-γ-inducible protein 10 and macrophage-inflammatory protein-1α in mouse adipose tissue. A selective EP4 antagonist (L161,982) reversed, and two structurally different selective EP4 agonists [CAY10580 and CAY10598] mimicked these actions of PGE2. Adipose tissue derived from EP4-deficient mice did not display this response. These findings establish the involvement of EP4 receptors in this anti-inflammatory response. Experiments performed on adipose tissue from high-fat-fed mice demonstrated EP4-dependent attenuation of chemokine production during diet-induced obesity. The anti-inflammatory actions of EP4 became more important on a high-fat diet, in that EP4 activation suppressed a greater variety of chemokines. Furthermore, adipose tissue and systemic inflammation was enhanced in high-fat-fed EP4-deficient mice compared with wild-type littermates, and in high-fat-fed untreated C57BL/6 mice compared with mice treated with EP4 agonist. These findings provide in vivo evidence that PGE2-EP4 signaling limits inflammation. In conclusion, PGE2, via activation of EP4 receptors, functions as an endogenous anti-inflammatory mediator in mouse adipose tissue, and targeting EP4 may mitigate adipose tissue inflammation. PMID:25510249

  14. Mest and Sfrp5 are biomarkers for healthy adipose tissue.

    PubMed

    Jura, Magdalena; Jarosławska, Julia; Chu, Dinh Toi; Kozak, Leslie P

    2016-05-01

    Obesity depends on a close interplay between genetic and environmental factors. However, it is unknown how these factors interact to cause changes in the obese condition during the progression of obesity from the neonatal to the aged individual. We have utilized Mest and Sfrp5 genes, two genes highly correlated with adipose tissue expansion in diet-induced obesity, to characterize the obese condition during development of 2 genetic models of obesity. A model for the early onset of obesity was presented by leptin-deficient mice (ob/ob), whereas late onset of obesity was induced with high-fat diet (HFD) consumption in C57BL/6J mice with inherent risk of obesity (DIO). We correlated obese and diabetic phenotypes with Mest and Sfrp5 gene expression profiles in subcutaneous fat during pre-weaning, pre-adulthood and adulthood. A rapid development of obesity began in ob/ob mice immediately after weaning at 21 days of age, whereas the obesity of DIO mice was not evident until after 2 months of age. Even after 5 months of HFD treatment, the adiposity index of DIO mice was lower than in ob/ob mice at 2 months of age. In both obesity models, the expression of Mest and Sfrp5 genes increased in parallel with fat mass expansion; however, gene expression proceeded to decrease when the adiposity reached a plateau. The reduction in the expression of genes of caveolae structure and glucose metabolism were also suppressed in the aging adipose tissue. The analysis of fat mass and adipocyte size suggests that reduction in Mest and Sfrp5 is more sensitive to the age of the fat than its morphology. The balance of factors controlling fat deposition can be evaluated in part by the differential expression profiles of Mest and Sfrp5 genes with functions linked to fat deposition as long as there is an active accumulation of fat mass. PMID:26001362

  15. IMMUNOLOGICAL GOINGS-ON IN VISCERAL ADIPOSE TISSUE

    PubMed Central

    Mathis, Diane

    2014-01-01

    Chronic, low-grade inflammation of visceral adipose tissue, and systemically, is a critical link between recent strikingly parallel rises in the incidence of obesity and type-2 diabetes. Macrophages have been recognized for some time to be critical participants in obesity-induced inflammation of adipose-tissue. Of late, a score of other cell-types of the innate and adaptive arms of the immune system have been suggested to play a positive or negative role in adipose-tissue infiltrates. This piece reviews the existing data on these new participants; discusses experimental uncertainties, inconsistencies and complexities; and puts forward a minimalist synthetic scheme. PMID:23747244

  16. 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.

  17. 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

  18. 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. PMID

  19. 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. PMID:21736766

  20. Isolation and Differentiation of Adipose-Derived Stem Cells from Porcine Subcutaneous Adipose Tissues

    PubMed Central

    Chen, Yu-Jen; Liu, Hui-Yu; Chang, Yun-Tsui; Cheng, Ying-Hung; Mersmann, Harry J.; Kuo, Wen-Hung; Ding, Shih-Torng

    2016-01-01

    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. PMID:27077225

  1. Adipocyte inflammation is essential for healthy adipose tissue expansion and remodeling.

    PubMed

    Wernstedt Asterholm, Ingrid; Tao, Caroline; Morley, Thomas S; Wang, Qiong A; Delgado-Lopez, Fernando; Wang, Zhao V; Scherer, Philipp E

    2014-07-01

    Chronic inflammation constitutes an important link between obesity and its pathophysiological sequelae. In contrast to the belief that inflammatory signals exert a fundamentally negative impact on metabolism, we show that proinflammatory signaling in the adipocyte is in fact required for proper adipose tissue remodeling and expansion. Three mouse models with an adipose tissue-specific reduction in proinflammatory potential were generated that display a reduced capacity for adipogenesis in vivo, while the differentiation potential is unaltered in vitro. Upon high-fat-diet exposure, the expansion of visceral adipose tissue is prominently affected. This is associated with decreased intestinal barrier function, increased hepatic steatosis, and metabolic dysfunction. An impaired local proinflammatory response in the adipocyte leads to increased ectopic lipid accumulation, glucose intolerance, and systemic inflammation. Adipose tissue inflammation is therefore an adaptive response that enables safe storage of excess nutrients and contributes to a visceral depot barrier that effectively filters gut-derived endotoxin. PMID:24930973

  2. 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

  3. Salsalate activates brown adipose tissue in mice.

    PubMed

    van Dam, Andrea D; Nahon, Kimberly J; Kooijman, Sander; van den Berg, Susan M; Kanhai, Anish A; Kikuchi, Takuya; Heemskerk, Mattijs M; van Harmelen, Vanessa; Lombès, Marc; van den Hoek, Anita M; de Winther, Menno P J; Lutgens, Esther; Guigas, Bruno; Rensen, Patrick C N; Boon, Mariëtte R

    2015-05-01

    Salsalate improves glucose intolerance and dyslipidemia in type 2 diabetes patients, but the mechanism is still unknown. The aim of the current study was to unravel the molecular mechanisms involved in these beneficial metabolic effects of salsalate by treating mice with salsalate during and after development of high-fat diet-induced obesity. We found that salsalate attenuated and reversed high-fat diet-induced weight gain, in particular fat mass accumulation, improved glucose tolerance, and lowered plasma triglyceride levels. Mechanistically, salsalate selectively promoted the uptake of fatty acids from glycerol tri[(3)H]oleate-labeled lipoprotein-like emulsion particles by brown adipose tissue (BAT), decreased the intracellular lipid content in BAT, and increased rectal temperature, all pointing to more active BAT. The treatment of differentiated T37i brown adipocytes with salsalate increased uncoupled respiration. Moreover, salsalate upregulated Ucp1 expression and enhanced glycerol release, a dual effect that was abolished by the inhibition of cAMP-dependent protein kinase (PKA). In conclusion, salsalate activates BAT, presumably by directly activating brown adipocytes via the PKA pathway, suggesting a novel mechanism that may explain its beneficial metabolic effects in type 2 diabetes patients. PMID:25475439

  4. Deep subcutaneous adipose tissue is more saturated than superficial subcutaneous adipose tissue.

    PubMed

    Lundbom, J; Hakkarainen, A; Lundbom, N; Taskinen, M-R

    2013-04-01

    Upper body abdominal subcutaneous adipose tissue (SAT) can be divided into deep SAT (DSAT) and superficial SAT (SSAT) depots. Studies on adipose tissue fatty acid (FA) composition have made no distinction between these two depots. The aim of this study is to determine whether DSAT and SSAT differ in FA composition. We studied the FA composition of DSAT and SSAT in 17 male and 13 female volunteers using non-invasive proton magnetic resonance spectroscopy in vivo. Magnetic resonance imaging was used to differentiate between DSAT and SSAT. Adipose tissue spectra were analysed for lipid unsaturation, or double bond (DB) content, and polyunsaturation (PU), according to previously validated methods. The DSAT depot was more saturated than the SSAT depot, in both men (0.833 ± 0.012 vs 0.846 ± 0.009 DB, P<0.002) and women (0.826 ± 0.018 vs 0.850 ± 0.018 DB, P<0.002). In contrast, PU did not differ between DSAT and SSAT in either men (0.449 ± 0.043 vs 0.461 ± 0.044 PU, P=0.125) or women (0.411 ± 0.070 vs 0.442 ± 0.062 PU, P=0.234) and displayed a close correlation between the depots (R=0.908, P<0.001, n=30). The higher saturation in DSAT compared with SSAT can be attributed to a higher ratio of saturated to monounsaturated FAs. These results should be taken into account when determining the FA composition of SAT. PMID:22641063

  5. Segmentation and quantification of adipose tissue by magnetic resonance imaging.

    PubMed

    Hu, Houchun Harry; Chen, Jun; Shen, Wei

    2016-04-01

    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

  6. Metabolic syndrome pathophysiology: the role of adipose tissue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Hepatic ANGPTL3 regulates adipose tissue energy homeostasis.

    PubMed

    Wang, Yan; McNutt, Markey C; Banfi, Serena; Levin, Michael G; Holland, William L; Gusarova, Viktoria; Gromada, Jesper; Cohen, Jonathan C; Hobbs, Helen H

    2015-09-15

    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

  8. 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

  9. Switch from Stress Response to Homeobox Transcription Factors in Adipose Tissue After Profound Fat Loss

    PubMed Central

    Stavrum, Anne-Kristin; Stansberg, Christine; Holdhus, Rita; Hoang, Tuyen; Veum, Vivian L.; Christensen, Bjørn Jostein; Våge, Villy; Sagen, Jørn V.; Steen, Vidar M.; Mellgren, Gunnar

    2010-01-01

    Background In obesity, impaired adipose tissue function may promote secondary disease through ectopic lipid accumulation and excess release of adipokines, resulting in systemic low-grade inflammation, insulin resistance and organ dysfunction. However, several of the genes regulating adipose tissue function in obesity are yet to be identified. Methodology/Principal Findings In order to identify novel candidate genes that may regulate adipose tissue function, we analyzed global gene expression in abdominal subcutaneous adipose tissue before and one year after bariatric surgery (biliopancreatic diversion with duodenal switch, BPD/DS) (n = 16). Adipose tissue from lean healthy individuals was also analyzed (n = 13). Two different microarray platforms (AB 1700 and Illumina) were used to measure the differential gene expression, and the results were further validated by qPCR. Surgery reduced BMI from 53.3 to 33.1 kg/m2. The majority of differentially expressed genes were down-regulated after profound fat loss, including transcription factors involved in stress response, inflammation, and immune cell function (e.g., FOS, JUN, ETS, C/EBPB, C/EBPD). Interestingly, a distinct set of genes was up-regulated after fat loss, including homeobox transcription factors (IRX3, IRX5, HOXA5, HOXA9, HOXB5, HOXC6, EMX2, PRRX1) and extracellular matrix structural proteins (COL1A1, COL1A2, COL3A1, COL5A1, COL6A3). Conclusions/Significance The data demonstrate a marked switch of transcription factors in adipose tissue after profound fat loss, providing new molecular insight into a dichotomy between stress response and metabolically favorable tissue development. Our findings implicate homeobox transcription factors as important regulators of adipose tissue function. PMID:20543949

  10. 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. PMID:27050305

  11. Myogenic potential of adipose-tissue-derived cells.

    PubMed

    Di Rocco, Giuliana; Iachininoto, Maria Grazia; Tritarelli, Alessandra; Straino, Stefania; Zacheo, Antonella; Germani, Antonia; Crea, Filippo; Capogrossi, Maurizio C

    2006-07-15

    Adipose-tissue-derived mesenchymal stem cells can be directed towards a myogenic phenotype in vitro by the addition of specific inductive media. However, the ability of these or other adipose-tissue-associated cells to respond to ;natural' myogenic cues such as a myogenic environment has never been investigated in detail. Here, we provide evidence that a restricted subpopulation of freshly harvested adipose-tissue-derived cells possesses an intrinsic myogenic potential and can spontaneously differentiate into skeletal muscle. Conversion of adipose-tissue-derived cells to a myogenic phenotype is enhanced by co-culture with primary myoblasts in the absence of cell contact and is maximal when the two cell types are co-cultured in the same plate. Conversely, in vitro expanded adipose-tissue-derived mesenchymal stem cells require direct contact with muscle cells to generate skeletal myotubes. Finally, we show that uncultured adipose-tissue-associated cells have a high regenerative capacity in vivo since they can be incorporated into muscle fibers following ischemia and can restore significantly dystrophin expression in mdx mice. PMID:16825428

  12. 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. PMID:23028044

  13. 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. PMID:24521443

  14. Profiling of chicken adipose tissue gene expression by genome array

    PubMed Central

    Wang, Hong-Bao; Li, Hui; Wang, Qi-Gui; Zhang, Xin-Yu; Wang, Shou-Zhi; Wang, Yu-Xiang; Wang, Xiu-Ping

    2007-01-01

    Background Excessive accumulation of lipids in the adipose tissue is a major problem in the present-day broiler industry. However, few studies have analyzed the expression of adipose tissue genes that are involved in pathways and mechanisms leading to adiposity in chickens. Gene expression profiling of chicken adipose tissue could provide key information about the ontogenesis of fatness and clarify the molecular mechanisms underlying obesity. In this study, Chicken Genome Arrays were used to construct an adipose tissue gene expression profile of 7-week-old broilers, and to screen adipose tissue genes that are differentially expressed in lean and fat lines divergently selected over eight generations for high and low abdominal fat weight. Results The gene expression profiles detected 13,234–16,858 probe sets in chicken adipose tissue at 7 weeks, and genes involved in lipid metabolism and immunity such as fatty acid binding protein (FABP), thyroid hormone-responsive protein (Spot14), lipoprotein lipase(LPL), insulin-like growth factor binding protein 7(IGFBP7) and major histocompatibility complex (MHC), were highly expressed. In contrast, some genes related to lipogenesis, such as leptin receptor, sterol regulatory element binding proteins1 (SREBP1), apolipoprotein B(ApoB) and insulin-like growth factor 2(IGF2), were not detected. Moreover, 230 genes that were differentially expressed between the two lines were screened out; these were mainly involved in lipid metabolism, signal transduction, energy metabolism, tumorigenesis and immunity. Subsequently, real-time RT-PCR was performed to validate fifteen differentially expressed genes screened out by the microarray approach and high consistency was observed between the two methods. Conclusion Our results establish the groundwork for further studies of the basic genetic control of growth and development of chicken adipose tissue, and will be beneficial in clarifying the molecular mechanism of obesity in chickens. PMID

  15. 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

  16. 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

  17. Adipose-derived stem cell differentiation as a basic tool for vascularized adipose tissue engineering.

    PubMed

    Volz, Ann-Cathrin; Huber, Birgit; Kluger, Petra J

    2016-01-01

    The development of in vitro adipose tissue constructs is highly desired to cope with the increased demand for substitutes to replace damaged soft tissue after high graded burns, deformities or tumor removal. To achieve clinically relevant dimensions, vascularization of soft tissue constructs becomes inevitable but still poses a challenge. Adipose-derived stem cells (ASCs) represent a promising cell source for the setup of vascularized fatty tissue constructs as they can be differentiated into adipocytes and endothelial cells in vitro and are thereby available in sufficiently high cell numbers. This review summarizes the currently known characteristics of ASCs and achievements in adipogenic and endothelial differentiation in vitro. Further, the interdependency of adipogenesis and angiogenesis based on the crosstalk of endothelial cells, stem cells and adipocytes is addressed at the molecular level. Finally, achievements and limitations of current co-culture conditions for the construction of vascularized adipose tissue are evaluated. PMID:26976717

  18. 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

  19. HIV Infection and Antiretroviral Therapy Have Divergent Effects on Mitochondria in Adipose Tissue

    PubMed Central

    Morse, Caryn G.; Voss, Joachim G.; Rakocevic, Goran; McLaughlin, Mary; Vinton, Carol L.; Huber, Charles; Hu, Xiaojun; Yang, Jun; Huang, Da Wei; Logun, Carolea; Danner, Robert L.; Rangel, Zoila G.; Munson, Peter J.; Orenstein, Jan M.; Rushing, Elisabeth J.; Lempicki, Richard A.; Dalakas, Marinos C.; Kovacs, Joseph A.

    2012-01-01

    Background. Although human immunodeficiency virus (HIV) infection and antiretroviral therapy (ART) affect mitochondrial DNA (mtDNA) content and function, comprehensive evaluations of their effects on mitochondria in muscle, adipose tissue, and blood cells are limited. Methods. Mitochondrial DNA quantification, mitochondrial genome sequencing, and gene expression analysis were performed on muscle, adipose tissue, and peripheral blood mononuclear cell (PBMC) samples from untreated HIV-positive patients, HIV-positive patients receiving nucleoside reverse transcriptase inhibitor (NRTI)–based ART, and HIV-negative controls. Results. The adipose tissue mtDNA/nuclear DNA (nDNA) ratio was increased in untreated HIV-infected patients (ratio, 353) and decreased in those receiving ART (ratio, 162) compared with controls (ratio, 255; P < .05 for both comparisons); the difference between the 2 HIV-infected groups was also significant (P = .002). In HIV-infected participants, mtDNA/nDNA in adipose tissue correlated with the level of activation (CD38+/HLA-DR+) for CD4+ and CD8+ lymphocytes. No significant differences in mtDNA content were noted in muscle or PMBCs among groups. Exploratory DNA microarray analysis identified differential gene expression between patient groups, including a subset of adipose tissue genes. Conclusions. HIV infection and ART have opposing effects on mtDNA content in adipose tissue; immune activation may mediate the effects of HIV, whereas NRTIs likely mediate the effects of ART. PMID:22476717

  20. 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

  1. 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.

  2. 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

  3. Exercise Regulation of Marrow Adipose Tissue.

    PubMed

    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 significantly

  4. 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. PMID:20421291

  5. Preventing diet-induced obesity in mice by adipose tissue transformation and angiogenesis using targeted nanoparticles.

    PubMed

    Xue, Yuan; Xu, Xiaoyang; Zhang, Xue-Qing; Farokhzad, Omid C; Langer, Robert

    2016-05-17

    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

  6. 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

  7. Adipose Tissue-Derived Mesenchymal Stem Cells Exert In Vitro Immunomodulatory and Beta Cell Protective Functions in Streptozotocin-Induced Diabetic Mice Model

    PubMed Central

    Rahavi, Hossein; Hashemi, Seyed Mahmoud; Soleimani, Masoud; Mohammadi, Jamal; Tajik, Nader

    2015-01-01

    Regenerative and immunomodulatory properties of mesenchymal stem cells (MSCs) might be applied for type 1 diabetes mellitus (T1DM) treatment. Thus, we proposed in vitro assessment of adipose tissue-derived MSCs (AT-MSCs) immunomodulation on autoimmune response along with beta cell protection in streptozotocin- (STZ-) induced diabetic C57BL/6 mice model. MSCs were extracted from abdominal adipose tissue of normal mice and cultured to proliferate. Diabetic mice were prepared by administration of multiple low-doses of streptozotocin. Pancreatic islets were isolated from normal mice and splenocytes prepared from normal and diabetic mice. Proliferation, cytokine production, and insulin secretion assays were performed in coculture experiments. AT-MSCs inhibited splenocytes proliferative response to specific (islet lysate) and nonspecific (PHA) triggers in a dose-dependent manner (P < 0.05). Decreased production of proinflammatory cytokines, such as IFN-γ, IL-2, and IL-17, and increased secretion of regulatory cytokines such as TGF-β, IL-4, IL-10, and IL-13 by stimulated splenocytes were also shown in response to islet lysate or PHA stimulants (P < 0.05). Finally, we demonstrated that AT-MSCs could effectively sustain viability as well as insulin secretion potential of pancreatic islets in the presence of reactive splenocytes (P < 0.05). In conclusion, it seems that MSCs may provide a new horizon for T1DM cell therapy and islet transplantation in the future. PMID:25893202

  8. 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

  9. 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

  10. Chromosome localization analysis of genes strongly expressed in human visceral adipose tissue.

    PubMed

    Yang, Yi-Sheng; Song, Huai-Dong; Shi, Wen-Jing; Hu, Ren-Ming; Han, Ze-Guang; Chen, Jia-Lun

    2002-06-01

    To understand fully the physiologic functions of visceral adipose tissue and to provide a basis for the identification of novel genes related to obesity and insulin resistance, the gene expression profiling of human visceral adipose tissue was established by using cDNA array. The characterization and chromosome localization of 400 expressed sequence tags (ESTs) strongly expressed in visceral adipose tissue were analyzed by searching PubMed, UniGene, the Human Genome Draft Database, and Location Data Base. Two hundred eighty-nine clones were classified into known genes among the 400 ESTs strongly expressed in the tissue. Among them, <20% have been previously reported to be expressed in adipose tissue. The chromosome localization of 389 ESTs strongly expressed in visceral adipose tissue showed that their relative abundance was significantly increased on chromosomes 1, 16, 19, 20, and 22 compared with the expected distribution of the same number of random genes. The intrachromosome distribution of the genes strongly expressed in visceral adipose tissue was concentrated in certain regions, such as 1p36.2-1p36.3, 6p21.3-6p22.1, 19p13.3 and 19q13.1. Among them, the region of 1p36.2-1p36.3 appeared to be specific for visceral adipose tissue. Interestingly, some genes playing an important role in the pathogenesis of insulin signal transduction and adipocyte differentiation, such as tumor necrosis factor-alpha and its receptors; CCAAT/enhancer-binding proteina; and phosphoinositide-3-kinase, regulatory subunit, polypeptide 2 (p85beta), were also localized in the concentrated regions, which may provide clues to identifying novel genes closely related to adipocyte function with potential pathophysiologic implications. PMID:12166625

  11. Control of adipose tissue lipolysis in ectotherm vertebrates.

    PubMed

    Migliorini, R H; Lima-Verde, J S; Machado, C R; Cardona, G M; Garofalo, M A; Kettelhut, I C

    1992-10-01

    Lipolytic activity of fish (Hoplias malabaricus), toad (Bufo paracnemis), and snake (Philodryas patagoniensis) adipose tissue was investigated in vivo and in vitro. Catecholamines or glucagon did not affect the release of free fatty acids (FFA) by incubated fish and toad adipose tissue. Catecholamines also failed to activate snake adipose tissue lipolysis, which even decreased in the presence of epinephrine. However, glucagon stimulated both the lipolytic activity of reptilian tissue in vitro and the mobilization of FFA to plasma when administered to snakes in vivo. The release of FFA from incubated fish, amphibian, and reptilian adipose tissue increased markedly in the presence of cAMP or xanthine derivatives, inhibitors of phosphodiesterase. Forskolin or fluoride, activators of specific components of the adenylate cyclase system, strongly stimulated toad adipose tissue lipolysis. The data suggest that adipocyte triacylglycerol lipase of ectotherm vertebrates is activated by a cAMP-mediated phosphorylation and that the organization of the membrane-bound adenylate cyclase system is similar to that of mammals. PMID:1329567

  12. 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

  13. Proteomic Analysis of Human Brown Adipose Tissue Reveals Utilization of Coupled and Uncoupled Energy Expenditure Pathways.

    PubMed

    Müller, Sebastian; Balaz, Miroslav; Stefanicka, Patrik; Varga, Lukas; Amri, Ez-Zoubir; Ukropec, Jozef; Wollscheid, Bernd; Wolfrum, Christian

    2016-01-01

    Human brown adipose tissue (BAT) has become an attractive target to combat the current epidemical spread of obesity and its associated co-morbidities. Currently, information on its functional role is primarily derived from rodent studies. Here, we present the first comparative proteotype analysis of primary human brown adipose tissue versus adjacent white adipose tissue, which reveals significant quantitative differences in protein abundances and in turn differential functional capabilities. The majority of the 318 proteins with increased abundance in BAT are associated with mitochondrial metabolism and confirm the increased oxidative capacity. In addition to uncoupling protein 1 (UCP1), the main functional effector for uncoupled respiration, we also detected the mitochondrial creatine kinases (CKMT1A/B, CKMT2), as effective modulators of ATP synthase coupled respiration, to be exclusively expressed in BAT. The abundant expression and utilization of both energy expenditure pathways in parallel highlights the complex functional involvement of BAT in human physiology. PMID:27418403

  14. Proteomic Analysis of Human Brown Adipose Tissue Reveals Utilization of Coupled and Uncoupled Energy Expenditure Pathways

    PubMed Central

    Müller, Sebastian; Balaz, Miroslav; Stefanicka, Patrik; Varga, Lukas; Amri, Ez-Zoubir; Ukropec, Jozef; Wollscheid, Bernd; Wolfrum, Christian

    2016-01-01

    Human brown adipose tissue (BAT) has become an attractive target to combat the current epidemical spread of obesity and its associated co-morbidities. Currently, information on its functional role is primarily derived from rodent studies. Here, we present the first comparative proteotype analysis of primary human brown adipose tissue versus adjacent white adipose tissue, which reveals significant quantitative differences in protein abundances and in turn differential functional capabilities. The majority of the 318 proteins with increased abundance in BAT are associated with mitochondrial metabolism and confirm the increased oxidative capacity. In addition to uncoupling protein 1 (UCP1), the main functional effector for uncoupled respiration, we also detected the mitochondrial creatine kinases (CKMT1A/B, CKMT2), as effective modulators of ATP synthase coupled respiration, to be exclusively expressed in BAT. The abundant expression and utilization of both energy expenditure pathways in parallel highlights the complex functional involvement of BAT in human physiology. PMID:27418403

  15. 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. PMID:26090087

  16. Adipose tissue-liver axis in alcoholic liver disease

    PubMed Central

    Wang, Zhi-Gang; Dou, Xiao-Bing; Zhou, Zhan-Xiang; Song, Zhen-Yuan

    2016-01-01

    Alcoholic liver disease (ALD) remains an important health problem worldwide. The disease spectrum is featured by early steatosis, steatohepatitis (steatosis with inflammatory cells infiltration and necrosis), with some individuals ultimately progressing to fibrosis/cirrhosis. Although the disease progression is well characterized, no effective therapies are currently available for the treatment in humans. The mechanisms underlying the initiation and progression of ALD are multifactorial and complex. Emerging evidence supports that adipose tissue dysfunction contributes to the pathogenesis of ALD. In the first part of this review, we discuss the mechanisms whereby chronic alcohol exposure contributed to adipose tissue dysfunction, including cell death, inflammation and insulin resistance. It has been long known that aberrant hepatic methionine metabolism is a major metabolic abnormality induced by chronic alcohol exposure and plays an etiological role in the pathogenesis of ALD. The recent studies in our group documented the similar metabolic effect of chronic alcohol drinking on methionine in adipose tissue. In the second part of this review, we also briefly discuss the recent research progress in the field with a focus on how abnormal methionine metabolism in adipose tissue contributes to adipose tissue dysfunction and liver damage. PMID:26909225

  17. Galectin-3 inhibition prevents adipose tissue remodelling in obesity.

    PubMed

    Martínez-Martínez, E; Calvier, L; Rossignol, P; Rousseau, E; Fernández-Celis, A; Jurado-López, R; Laville, M; Cachofeiro, V; López-Andrés, N

    2016-06-01

    Extracellular matrix remodelling of the adipose tissue has a pivotal role in the pathophysiology of obesity. Galectin-3 (Gal-3) is increased in obesity and mediates inflammation and fibrosis in the cardiovascular system. However, the effects of Gal-3 on adipose tissue remodelling associated with obesity remain unclear. Male Wistar rats were fed either a high-fat diet (33.5% fat) or a standard diet (3.5% fat) for 6 weeks. Half of the animals of each group were treated with the pharmacological inhibitor of Gal-3, modified citrus pectin (MCP; 100 mg kg(-1) per day) in the drinking water. In adipose tissue, obese animals presented an increase in Gal-3 levels that were accompanied by an increase in pericellular collagen. Obese rats exhibited higher adipose tissue inflammation, as well as enhanced differentiation degree of the adipocytes. Treatment with MCP prevented all the above effects. In mature 3T3-L1 adipocytes, Gal-3 (10(-8 )m) treatment increased fibrosis, inflammatory and differentiation markers. In conclusion, Gal-3 emerges as a potential therapeutic target in adipose tissue remodelling associated with obesity and could have an important role in the development of metabolic alterations associated with obesity. PMID:26853916

  18. Adipose tissue-liver axis in alcoholic liver disease.

    PubMed

    Wang, Zhi-Gang; Dou, Xiao-Bing; Zhou, Zhan-Xiang; Song, Zhen-Yuan

    2016-02-15

    Alcoholic liver disease (ALD) remains an important health problem worldwide. The disease spectrum is featured by early steatosis, steatohepatitis (steatosis with inflammatory cells infiltration and necrosis), with some individuals ultimately progressing to fibrosis/cirrhosis. Although the disease progression is well characterized, no effective therapies are currently available for the treatment in humans. The mechanisms underlying the initiation and progression of ALD are multifactorial and complex. Emerging evidence supports that adipose tissue dysfunction contributes to the pathogenesis of ALD. In the first part of this review, we discuss the mechanisms whereby chronic alcohol exposure contributed to adipose tissue dysfunction, including cell death, inflammation and insulin resistance. It has been long known that aberrant hepatic methionine metabolism is a major metabolic abnormality induced by chronic alcohol exposure and plays an etiological role in the pathogenesis of ALD. The recent studies in our group documented the similar metabolic effect of chronic alcohol drinking on methionine in adipose tissue. In the second part of this review, we also briefly discuss the recent research progress in the field with a focus on how abnormal methionine metabolism in adipose tissue contributes to adipose tissue dysfunction and liver damage. PMID:26909225

  19. Adipocyte glucocorticoid receptor has a minor contribution in adipose tissue growth.

    PubMed

    Desarzens, Sébastien; Faresse, Nourdine

    2016-07-01

    The glucocorticoids bind and activate both the glucocorticoid receptor (GR) as well as the mineralocorticoid receptor in adipocytes. Despite several studies to determine the function of these two receptors in mediating glucocorticoids effects, their relative contribution in adipose tissue expansion and obesity is unclear. To investigate the effect of GR in adipose tissue function, we generated an adipocyte-specific Gr-knockout mouse model (Gr(ad-ko)). These mice were submitted either to a standard diet or a high-fat high sucrose diet. We found that adipocyte-specific deletion of Gr did not affect body weight gain or adipose tissue formation and distribution. However, the lack of Gr in adipocyte promotes a diet-induced inflammation determined by higher pro-inflammatory genes expression and macrophage infiltration in the fat pads. Surprisingly, the adipose tissue inflammation in Gr(ad-ko) mice was not correlated with insulin resistance or dyslipidemia, but with disturbed glucose tolerance. Our data demonstrate that adipocyte-specific ablation of Gr in vivo may affect the adipose tissue function but not its expansion during a high calorie diet. PMID:27106108

  20. Circulating Blood Monocyte Subclasses and Lipid-Laden Adipose Tissue Macrophages in Human Obesity

    PubMed Central

    Pecht, Tal; Haim, Yulia; Bashan, Nava; Shapiro, Hagit; Harman-Boehm, Ilana; Kirshtein, Boris; Clément, Karine; Shai, Iris; Rudich, Assaf

    2016-01-01

    Background Visceral adipose tissue foam cells are increased in human obesity, and were implicated in adipose dysfunction and increased cardio-metabolic risk. In the circulation, non-classical monocytes (NCM) are elevated in obesity and associate with atherosclerosis and type 2 diabetes. We hypothesized that circulating NCM correlate and/or are functionally linked to visceral adipose tissue foam cells in obesity, potentially providing an approach to estimate visceral adipose tissue status in the non-surgical obese patient. Methods We preformed ex-vivo functional studies utilizing sorted monocyte subclasses from healthy donors. Moreover, we assessed circulating blood monocyte subclasses and visceral fat adipose tissue macrophage (ATM) lipid content by flow-cytometry in paired blood and omental-fat samples collected from patients (n = 65) undergoing elective abdominal surgery. Results Ex-vivo, NCM and NCM-derived macrophages exhibited lower lipid accumulation capacity compared to classical or intermediate monocytes/-derived macrophages. Moreover, of the three subclasses, NCM exhibited the lowest migration towards adipose tissue conditioned-media. In a cohort of n = 65, increased %NCM associated with higher BMI (r = 0.250,p<0.05) and ATM lipid content (r = 0.303,p<0.05). Among patients with BMI≥25Kg/m2, linear regression models adjusted for age, sex or BMI revealed that NCM independently associate with ATM lipid content, particularly in men. Conclusions Collectively, although circulating blood NCM are unlikely direct functional precursor cells for adipose tissue foam cells, their increased percentage in the circulation may clinically reflect higher lipid content in visceral ATMs. PMID:27442250

  1. In vivo Analysis of White Adipose Tissue in Zebrafish

    PubMed Central

    Minchin, James E.N.; Rawls, John F.

    2016-01-01

    White adipose tissue (WAT) is the major site of energy storage in bony vertebrates, and also serves central roles in the endocrine regulation of energy balance. The cellular and molecular mechanisms underlying WAT development and physiology are not well understood. This is due in part to difficulties associated with imaging adipose tissues in mammalian model systems, especially during early life stages. The zebrafish (Danio rerio) has recently emerged as a new model system for adipose tissue research, in which WAT can be imaged in a transparent living vertebrate at all life stages. Here we present detailed methods for labeling adipocytes in live zebrafish using fluorescent lipophilic dyes, and for in vivo microscopy of zebrafish WAT. PMID:21951526

  2. 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

  3. 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.

  4. Adipose tissue depot specific differences of PLIN protein content in endurance trained rats.

    PubMed

    Ramos, Sofhia V; Turnbull, Patrick C; MacPherson, Rebecca E K

    2016-01-01

    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

  5. Adipose tissue remodeling in a novel domestic porcine model of diet-induced obesity

    PubMed Central

    Pawar, Aditya S.; Zhu, Xiang-Yang; Eirin, Alfonso; Tang, Hui; Jordan, Kyra L.; Woollard, John R.; Lerman, Amir; Lerman, Lilach O.

    2014-01-01

    Objective To establish and characterize a novel domestic porcine model of obesity. Design and Methods Fourteen domestic pigs were fed normal (lean, n=7) or high-fat/high-fructose diet (obese, n=7) for 16 weeks. Subcutaneous abdominal adipose tissue biopsies were obtained after 8, 12 and 16 weeks of diet, and pericardial adipose tissue after 16 weeks, for assessments of adipocyte size, fibrosis, and inflammation. Adipose tissue volume and cardiac function were studied with multi-detector computed-tomography, and oxygenation with magnetic resonance imaging. Plasma lipids profiles, insulin resistance, and markers of inflammation were evaluated. Results Compared with lean, obese pigs had elevated cholesterol and triglycerides levels, blood pressure, and insulin resistance. Both abdominal and pericardial fat volume increased after 16 weeks of obese. In abdominal subcutaneous adipose tissue, adipocyte size and both tumor necrosis factor (TNF)-α expression progressively increased. Macrophage infiltration showed in both abdominal and pericardial adipose tissues. Circulating TNF-α increased in obese only at 16 weeks. Compared with Lean, obese pigs had similar global cardiac function, but myocardial perfusion and oxygenation were significantly impaired. Conclusion A high-fat/high-fructose diet induces in domestic pigs many characteristics of metabolic syndrome, which is useful to investigate the effects of the obesity. PMID:25627626

  6. 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. PMID:26859602

  7. The role of epicardial and perivascular adipose tissue in the pathophysiology of cardiovascular disease

    PubMed Central

    Ouwens, D Margriet; Sell, Henrike; Greulich, Sabrina; Eckel, Juergen

    2010-01-01

    Abstract Obesity, insulin resistance and the metabolic syndrome, are characterized by expansion and inflammation of adipose tissue, including the depots surrounding the heart and the blood vessels. Epicardial adipose tissue (EAT) is a visceral thoracic fat depot located along the large coronary arteries and on the surface of the ventricles and the apex of the heart, whereas perivascular adipose tissue (PVAT) surrounds the arteries. Both fat depots are not separated by a fascia from the underlying tissue. Therefore, factors secreted from epicardial and PVAT, like free fatty acids and adipokines, can directly affect the function of the heart and blood vessels. In this review, we describe the alterations found in EAT and PVAT in pathological states like obesity, type 2 diabetes, the metabolic syndrome and coronary artery disease. Furthermore, we discuss how changes in adipokine expression and secretion associated with these pathological states could contribute to the pathogenesis of cardiac contractile and vascular dysfunction. PMID:20716126

  8. 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.

  9. Brown adipose tissue: The heat is on the heart.

    PubMed

    Thoonen, Robrecht; Hindle, Allyson G; Scherrer-Crosbie, Marielle

    2016-06-01

    The study of brown adipose tissue (BAT) has gained significant scientific interest since the discovery of functional BAT in adult humans. The thermogenic properties of BAT are well recognized; however, data generated in the last decade in both rodents and humans reveal therapeutic potential for BAT against metabolic disorders and obesity. Here we review the current literature in light of a potential role for BAT in beneficially mediating cardiovascular health. We focus mainly on BAT's actions in obesity, vascular tone, and glucose and lipid metabolism. Furthermore, we discuss the recently discovered endocrine factors that have a potential beneficial role in cardiovascular health. These BAT-secreted factors may have a favorable effect against cardiovascular risk either through their metabolic role or by directly affecting the heart. PMID:27084389

  10. 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. PMID:26592777

  11. 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

  12. Natural Killer T Cells in Adipose Tissue Are Activated in Lean Mice

    PubMed Central

    Kondo, Taisuke; Toyoshima, Yujiro; Ishii, Yoshiyuki; Kyuwa, Shigeru

    2013-01-01

    Adipose tissues are closely connected with the immune system. It has been suggested that metabolic syndromes such as type 2 diabetes, arteriosclerosis and liver steatosis can be attributed to adipose tissue inflammation characterized by macrophage infiltration. To understand a physiological and pathological role of natural killer T (NKT) cells on inflammation in adipose tissue, we characterized a subset of NKT cells in abdominal and subcutaneous adipose tissues in C57BL/6J mice fed normal or high-fat diets. NKT cells comprised a larger portion of lymphocytes in adipose tissues compared with the spleen and peripheral blood, with epididymal adipose tissue having the highest number of NKT cells. Furthermore, some NKT cells in adipose tissues expressed higher levels of CD69 and intracellular interferon-γ, whereas the Vβ repertoires of NKT cells in adipose tissues were similar to other cells. In obese mice fed a high-fat diet, adipose tissue inflammation had little effect on the Vβ repertoire of NKT cells in epididymal adipose tissues. We speculate that the NKT cells in adipose tissues may form an equivalent subset in other tissues and that these subsets are likely to participate in adipose tissue inflammation. Additionally, the high expression level of CD69 and intracellular IFN-γ raises the possibility that NKT cells in adipose tissue may be stimulated by some physiological mechanism. PMID:24172196

  13. 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

  14. Elevated Endoplasmic Reticulum Stress Response Contributes to Adipose Tissue Inflammation in Aging.

    PubMed

    Ghosh, Amiya Kumar; Garg, Sanjay Kumar; Mau, Theresa; O'Brien, Martin; Liu, Jianhua; Yung, Raymond

    2015-11-01

    Adipose tissue inflammation has been linked to age-related metabolic diseases. However, the underlying mechanisms are poorly understood. Adipose tissue inflammation and insulin resistance in diet associated obesity has been correlated with aberrant endoplasmic reticulum (ER) stress. This study was undertaken to test our hypothesis that increased ER stress response contributes to age-associated adipose tissue inflammation. We found elevated ER stress response in adipose tissue of old (18-20 months) compared to young (4-6 months) mice. Elevated ER stress markers BIP (GRP78), CHOP, cleaved-ATF-6, phospho-IRE1α, and XBP-1 were observed in old compared to young adipose tissue stromal cells. Additionally, old adipose tissue stromal cells were more sensitive to an ER stress inducer, thapsigargin. Similar experiments with adipose tissue macrophages showed elevated Chop and Bip expression in old adipose tissue macrophages when induced with thapsigargin. Treatment of chemical chaperone 4-phenyle-butyric acid alleviated ER stress in adipose tissue stromal cells and adipose tissue macrophages and attenuated the production of IL-6 and MCP-1 by adipose tissue stromal cells, and TNF-α by adipose tissue macrophages from both young and old mice. Finally, old mice fed with 4-phenyle-butyric acid have reduced expression of ER stress and inflammatory cytokine genes. Our data suggests that an exaggerated ER stress response in aging adipose tissue contributes to age-associated inflammation that can be mitigated by treatment with chemical chaperones. PMID:25324219

  15. Fyn Deficiency Promotes a Preferential Increase in Subcutaneous Adipose Tissue Mass and Decreased Visceral Adipose Tissue Inflammation

    PubMed Central

    Lee, Ting-Wen A.; Kwon, Hyokjoon; Zong, Haihong; Yamada, Eijiro; Vatish, Manu; Pessin, Jeffrey E.; Bastie, Claire C.

    2013-01-01

    Previous studies have demonstrated that Fyn knockout (FynKO) mice on a standard chow diet display increased glucose clearance and whole-body insulin sensitivity associated with decreased adiposity resulting from increased fatty acid use and energy expenditure. Surprisingly, however, despite a similar extent of adipose tissue (AT) mass accumulation on a high-fat diet, the FynKO mice remained fully glucose tolerant and insulin sensitive. Physiologic analyses demonstrated that the FynKO mice had a combination of skewed AT expansion into the subcutaneous compartment rather than to the visceral depot, reduced AT inflammation associated with reduced T-cell and macrophage infiltration, and increased proportion of anti-inflammatory M2 macrophages. These data demonstrate that Fyn is an important regulator of whole-body integrative metabolism that coordinates AT expansion, inflammation, and insulin sensitivity in states of nutrient excess. These data further suggest that inhibition of Fyn function may provide a novel target to prevent AT inflammation, insulin resistance, and the dyslipidemia components of the metabolic syndrome. PMID:23321073

  16. Curcumin inhibits lipolysis via suppression of ER stress in adipose tissue and prevents hepatic insulin resistance.

    PubMed

    Wang, Lulu; Zhang, Bangling; Huang, Fang; Liu, Baolin; Xie, Yuan

    2016-07-01

    Curcumin is natural polyphenol with beneficial effects on lipid and glucose metabolism and this study aimed to investigate the effects of curcumin on lipolysis and hepatic insulin resistance. Endoplasmic reticulum (ER) stress and lipolysis signaling in adipose and FFA influx, lipid deposits, and glucose production in liver were examined. Palmitate challenge and high-fat diet feeding evoked ER stress-associated lipolysis with cAMP accumulation in adipose tissue. Curcumin treatment inhibited adipose tissue ER stress by dephosphorylation of inositol-requiring enzyme 1α and eukaryotic initiation factor 2α and reduced cAMP accumulation by preserving phosphodiesterase 3B induction. Knockdown of mitogen-activated protein kinase α1/2α with siRNAs diminished such effects of curcumin. As a result from downregulation of cAMP, curcumin blocked protein kinase (PK)A/hormone-sensitive lipase lipolysis signaling, and thereby reduced glycerol and FFA release from adipose tissue. Curcumin reduced FFA influx into the liver by blocking FFA trafficking, and then prevented diacylglycerol deposits and PKCε translocation in the liver, resultantly improving insulin action in the suppression of hepatic gluconeogenesis. Curcumin decreased adipose lipolysis by attenuating ER stress through the cAMP/PKA pathway, reduced FFA influx into the liver by blocking FFA trafficking, and thereby improved insulin sensitivity to inhibit hepatic glucose production. These findings suggested a novel pathway of curcumin to prevent lipid deposits and insulin resistance in liver by beneficial regulation of adipose function. PMID:27220352

  17. Subcutaneous Adipose Tissue Transplantation in Diet-Induced Obese Mice Attenuates Metabolic Dysregulation While Removal Exacerbates It.

    PubMed

    Foster, M T; Softic, S; Caldwell, J; Kohli, R; de Kloet, A D; Seeley, R J

    2013-08-01

    Adipose tissue distribution is an important determinant of obesity-related comorbidities. It is well established that central obesity (visceral adipose tissue accumulation) is a risk factor for many adverse health consequences such as dyslipidemia, insulin resistance and type-2-diabetes. We hypothesize that the metabolic dysregulation that occurs following high fat diet-induced increases in adiposity are due to alterations in visceral adipose tissue function which influence lipid flux to the liver via the portal vein. This metabolic pathology is not exclusively due to increases in visceral adipose tissue mass but also driven by intrinsic characteristics of this particular depot. In Experiment 1, high fat diet (HFD)-induced obese control (abdominal incision, but no fat manipulation) or autologous (excision and subsequent relocation of adipose tissue) subcutaneous tissue transplantation to the visceral cavity. In Experiment 2 mice received control surgery, subcutaneous fat removal or hetero-transplantation (tissue from obese donor) to the visceral cavity. Body composition analysis and glucose tolerance tests were performed 4 weeks post-surgery. Adipose mass and portal adipokines, cytokines, lipids and insulin were measured from samples collected at 5 weeks post-surgery. Auto- and hetero- transplantation in obese mice improved glucose tolerance, decreased systemic insulin concentration and reduced portal lipids and hepatic triglycerides compared with HFD controls. Hetero-transplantation of subcutaneous adipose tissue to the visceral cavity in obese mice restored hepatic insulin sensitivity and reduced insulin and leptin concentrations to chow control levels. Fat removal, however, as an independent procedure exacerbated obesity-induced increases in leptin and insulin concentrations. Overall subcutaneous adipose tissue protects against aspects of metabolic dysregulation in obese mice. Transplantation-induced improvements do not occur via enhanced storage of lipid in

  18. Maternal nutritional manipulations program adipose tissue dysfunction in offspring.

    PubMed

    Lecoutre, Simon; Breton, Christophe

    2015-01-01

    Based on the concept of Developmental Origin of Health and Disease, both human and animal studies have demonstrated a close link between nutrient supply perturbations in the fetus or neonate (i.e., maternal undernutrition, obesity, gestational diabetes and/or rapid catch-up growth) and increased risk of adult-onset obesity. Indeed, the adipose tissue has been recognized as a key target of developmental programming in a sex-and depot-specific manner. Despite different developmental time windows, similar mechanisms of adipose tissue programming have been described in rodents and in bigger mammals (sheep, primates). Maternal nutritional manipulations reprogram offspring's adipose tissue resulting in series of alterations: enhanced adipogenesis and lipogenesis, impaired sympathetic activity with reduced noradrenergic innervations and thermogenesis as well as low-grade inflammation. These changes affect adipose tissue development, distribution and composition predisposing offspring to fat accumulation. Modifications of hormonal tissue sensitivity (i.e., leptin, insulin, glucocorticoids) and/or epigenetic mechanisms leading to persistent changes in gene expression may account for long-lasting programming across generations. PMID:26029119

  19. Putative population of adipose-derived stem cells isolated from mediastinal tissue during cardiac surgery.

    PubMed

    Patel, Amit N; Yockman, James; Vargas, Vanessa; Bull, David A

    2013-01-01

    Mesenchymal stem cells have been isolated from various adult human tissues and are valuable for not only therapeutic applications but for the study of tissue homeostasis and disease progression. Subcutaneous adipose depots have been shown to contain large amounts of stem cells. There is little information that has been reported to date describing the isolation and characterization of mesenchymal stem cells from visceral adipose tissue. In this study, we describe a mesenchymal stem cell population isolated from mediastinal adipose depots. The cells express CD44, CD105, CD166, and CD90 and are negative for hematopoietic markers CD34, CD45, and HLA-DR. In addition, the cells have a multilineage potential, with the ability to differentiate into adipogenic, osteogenic, and chondrogenic cell types. The biological function of visceral adipose tissue remains largely unknown and uncharacterized. However, the proximity of adipose tissue to the heart suggests a potential role in the pathogenesis of cardiovascular disease in obesity. In addition, with the ability of fat to regulate metabolic activity in humans, this novel stem cell source may be useful to further study the mechanisms involved in metabolic disorders. PMID:22490339

  20. Simple and longstanding adipose tissue engineering in rabbits.

    PubMed

    Tsuji, Wakako; Inamoto, Takashi; Ito, Ran; Morimoto, Naoki; Tabata, Yasuhiko; Toi, Masakazu

    2013-03-01

    Adipose tissue engineering for breast reconstruction can be performed for patients who have undergone breast surgery. We have previously confirmed adipogenesis in mice implanted with type I collagen sponge with controlled release of fibroblast growth factor 2 (FGF2) and human adipose tissue-derived stem cells. However, in order to use this approach to treat breast cancer patients, a large amount of adipose tissue is needed, and FGF2 is not readily available. Thus, we aimed to regenerate large amounts of adipose tissue without FGF2 for a long period. Under general anesthesia, cages made of polypropylene mesh were implanted into the rabbits' bilateral fat pads. Each cage was 10 mm in radius and 10 mm in height. Minced type I collagen sponge was injected as a scaffold into the cage. Regenerated tissue in the cage was examined with ultrasonography, and the cages were harvested 3, 6, and 12 months after the implantation. Ultrasonography revealed a gradually increasing homogeneous high-echo area in the cage. Histology of the specimen was assessed with hematoxylin and eosin staining. The percentages of regenerated adipose tissue area were 76.2 ± 13.0 and 92.8 ± 6.6 % at 6 and 12 months after the implantation, respectively. Our results showed de novo adipogenesis 12 months after the implantation of only type I collagen sponge inside the space. Ultrasonography is a noninvasive and useful method of assessing the growth of the tissue inside the cage. This simple method could be a promising clinical modality in breast reconstruction. PMID:23114565

  1. Numerous Genes in Loci Associated With Body Fat Distribution Are Linked to Adipose Function.

    PubMed

    Dahlman, Ingrid; Rydén, Mikael; Brodin, David; Grallert, Harald; Strawbridge, Rona J; Arner, Peter

    2016-02-01

    Central fat accumulation is a strong risk factor for type 2 diabetes. Genome-wide association studies have identified numerous loci associated with body fat distribution. The objectives of the current study are to examine whether genes in genetic loci linked to fat distribution can be linked to fat cell size and number (morphology) and/or adipose tissue function. We show, in a cohort of 114 women, that almost half of the 96 genes in these loci are indeed associated with abdominal subcutaneous adipose tissue parameters. Thus, adipose mRNA expression of the genes is strongly related to adipose morphology, catecholamine-induced lipid mobilization (lipolysis), or insulin-stimulated lipid synthesis in adipocytes (lipogenesis). In conclusion, the genetic influence on body fat distribution could be mediated via several specific alterations in adipose tissue morphology and function, which in turn may influence the development of type 2 diabetes. PMID:26798124

  2. Intra-abdominal fat. Part I. The images of the adipose tissue localized beyond organs

    PubMed Central

    Kołaczyk, Katarzyna; Bernatowicz, Elżbieta

    2015-01-01

    Unaltered fat is a permanent component of the abdominal cavity, even in slim individuals. Visceral adiposity is one of the important factors contributing to diabetes, cardiovascular diseases and certain neoplasms. Moreover, the adipose tissue is an important endocrine and immune organ of complex function both when normal and pathological. Its role in plastic surgery, reconstruction and transplantology is a separate issue. The adipose tissue has recently drawn the attention of research institutes owing to being a rich source of stem cells. This review, however, does not include these issues. The identification of fat is relatively easy using computed tomography and magnetic resonance imaging. It can be more difficult in an ultrasound examination for several reasons. The aim of this paper is to present various problems associated with US imaging of unaltered intra-abdominal fat located beyond organs. Based on the literature and experience, it has been demonstrated that the adipose tissue in the abdominal cavity has variable echogenicity, which primarily depends on the amount of extracellular fluid and the number of connective tissue septa, i.e. elements that potentiate the number of areas that reflect and scatter ultrasonic waves. The normal adipose tissue presents itself on a broad gray scale: from a hyperechoic area, through numerous structures of lower reflection intensity, to nearly anechoic regions mimicking the presence of pathological fluid collections. The features that facilitate proper identification of this tissue are: sharp margins, homogeneous structure, high compressibility under transducer pressure, no signs of infiltration of the surrounding structures and no signs of vascularization when examined with the color and power Doppler. The accumulation of fat tissue in the abdominal cavity can be generalized, regional or focal. The identification of the adipose tissue in the abdominal cavity using ultrasonography is not always easy. When in doubt, the

  3. Intra-abdominal fat. Part I. The images of the adipose tissue localized beyond organs.

    PubMed

    Smereczyński, Andrzej; Kołaczyk, Katarzyna; Bernatowicz, Elżbieta

    2015-09-01

    Unaltered fat is a permanent component of the abdominal cavity, even in slim individuals. Visceral adiposity is one of the important factors contributing to diabetes, cardiovascular diseases and certain neoplasms. Moreover, the adipose tissue is an important endocrine and immune organ of complex function both when normal and pathological. Its role in plastic surgery, reconstruction and transplantology is a separate issue. The adipose tissue has recently drawn the attention of research institutes owing to being a rich source of stem cells. This review, however, does not include these issues. The identification of fat is relatively easy using computed tomography and magnetic resonance imaging. It can be more difficult in an ultrasound examination for several reasons. The aim of this paper is to present various problems associated with US imaging of unaltered intra-abdominal fat located beyond organs. Based on the literature and experience, it has been demonstrated that the adipose tissue in the abdominal cavity has variable echogenicity, which primarily depends on the amount of extracellular fluid and the number of connective tissue septa, i.e. elements that potentiate the number of areas that reflect and scatter ultrasonic waves. The normal adipose tissue presents itself on a broad gray scale: from a hyperechoic area, through numerous structures of lower reflection intensity, to nearly anechoic regions mimicking the presence of pathological fluid collections. The features that facilitate proper identification of this tissue are: sharp margins, homogeneous structure, high compressibility under transducer pressure, no signs of infiltration of the surrounding structures and no signs of vascularization when examined with the color and power Doppler. The accumulation of fat tissue in the abdominal cavity can be generalized, regional or focal. The identification of the adipose tissue in the abdominal cavity using ultrasonography is not always easy. When in doubt, the

  4. Adipose tissue plasticity: how fat depots respond differently to pathophysiological cues.

    PubMed

    Pellegrinelli, Vanessa; Carobbio, Stefania; Vidal-Puig, Antonio

    2016-06-01

    White adipose tissue (WAT) has key metabolic and endocrine functions and plays a role in regulating energy homeostasis and insulin sensitivity. WAT is characterised by its capacity to adapt and expand in response to surplus energy through processes of adipocyte hypertrophy and/or recruitment and proliferation of precursor cells in combination with vascular and extracellular matrix remodelling. However, in the context of sustained obesity, WAT undergoes fibro-inflammation, which compromises its functionality, contributing to increased risk of type 2 diabetes and cardiovascular diseases. Conversely, brown adipose tissue (BAT) and browning of WAT represent potential therapeutic approaches, since dysfunctional white adipocyte-induced lipid overspill can be halted by BAT/browning-mediated oxidative anti-lipotoxic effects. Better understanding of the cellular and molecular pathophysiological mechanisms regulating adipocyte size, number and depot-dependent expansion has become a focus of interest over recent decades. Here, we summarise the mechanisms contributing to adipose tissue (AT) plasticity and function including characteristics and cellular complexity of the various adipose depots and we discuss recent insights into AT origins, identification of adipose precursors, pathophysiological regulation of adipogenesis and its relation to WAT/BAT expandability in obesity and its associated comorbidities. PMID:27039901

  5. Brown Adipose Tissue Activation Is Linked to Distinct Systemic Effects on Lipid Metabolism in Humans.

    PubMed

    Chondronikola, Maria; Volpi, Elena; Børsheim, Elisabet; Porter, Craig; Saraf, Manish K; Annamalai, Palam; Yfanti, Christina; Chao, Tony; Wong, Daniel; Shinoda, Kosaku; Labbė, Sebastien M; Hurren, Nicholas M; Cesani, Fernardo; Kajimura, Shingo; Sidossis, Labros S

    2016-06-14

    Recent studies suggest that brown adipose tissue (BAT) plays a role in energy and glucose metabolism in humans. However, the physiological significance of human BAT in lipid metabolism remains unknown. We studied 16 overweight/obese men during prolonged, non-shivering cold and thermoneutral conditions using stable isotopic tracer methodologies in conjunction with hyperinsulinemic-euglycemic clamps and BAT and white adipose tissue (WAT) biopsies. BAT volume was significantly associated with increased whole-body lipolysis, triglyceride-free fatty acid (FFA) cycling, FFA oxidation, and adipose tissue insulin sensitivity. Functional analysis of BAT and WAT demonstrated the greater thermogenic capacity of BAT compared to WAT, while molecular analysis revealed a cold-induced upregulation of genes involved in lipid metabolism only in BAT. The accelerated mobilization and oxidation of lipids upon BAT activation supports a putative role for BAT in the regulation of lipid metabolism in humans. PMID:27238638

  6. Adipocyte Death, Adipose Tissue Remodeling and Obesity Complications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to determine the role of adipocyte death in obesity-induced adipose tissue (AT) inflammation and obesity complications. Male C57BL/6 mice were fed a high fat diet for 20 weeks to induce obesity. Every four weeks, insulin resistance (IR) was assessed by intraperitoneal...

  7. Endotrophin triggers adipose tissue fibrosis and metabolic dysfunction

    PubMed Central

    Sun, Kai; Park, Jiyoung; Gupta, Olga T.; Holland, William L.; Auerbach, Pernille; Zhang, Ningyan; Marangoni, Roberta Goncalves; Nicoloro, Sarah M.; Czech, Michael P.; Varga, John; Ploug, Thorkil; An, Zhiqiang; Scherer, Philipp E.

    2014-01-01

    We recently identified endotrophin as an adipokine with potent tumour-promoting effects. However, the direct effects of local accumulation of endotrophin in adipose tissue have not yet been studied. Here we use a doxycycline-inducible adipocyte-specific endotrophin overexpression model to demonstrate that endotrophin plays a pivotal role in shaping a metabolically unfavourable microenvironment in adipose tissue during consumption of a high-fat diet (HFD). Endotrophin serves as a powerful co-stimulator of pathologically relevant pathways within the ‘unhealthy’ adipose tissue milieu, triggering fibrosis and inflammation and ultimately leading to enhanced insulin resistance. We further demonstrate that blocking endotrophin with a neutralizing antibody ameliorates metabolically adverse effects and effectively reverses metabolic dysfunction induced during HFD exposure. Collectively, our findings demonstrate that endotrophin exerts a major influence in adipose tissue, eventually resulting in systemic elevation of pro-inflammatory cytokines and insulin resistance, and the results establish endotrophin as a potential target in the context of metabolism and cancer. PMID:24647224

  8. Colonic Macrophages "Remote Control" Adipose Tissue Inflammation and Insulin Resistance.

    PubMed

    Biswas, Subhra K; Bonecchi, Raffaella

    2016-08-01

    The early events linking diet-induced adipose tissue inflammation and insulin resistance remain poorly understood. In this issue of Cell Metabolism, Kawano et al. (2016) show that infiltration of colonic pro-inflammatory macrophages orchestrated by the intestinal CCL2/CCR2 axis kick-starts this process during high-fat-diet feeding. PMID:27508866

  9. Lipolytic and thermogenic depletion of adipose tissue in cancer cachexia.

    PubMed

    Tsoli, Maria; Swarbrick, Michael M; Robertson, Graham R

    2016-06-01

    Although muscle wasting is the obvious manifestation of cancer cachexia that impacts on patient quality of life, the loss of lipid reserves and metabolic imbalance in adipose tissue also contribute to the devastating impact of cachexia. Depletion of fat depots in cancer patients is more pronounced than loss of muscle and often precedes, or even occurs in the absence of, reduced lean body mass. Rapid mobilisation of triglycerides stored within adipocytes to supply the body with fatty acids in periods of high-energy demand is normally mediated through a well-defined process of lipolysis involving the lipases ATGL, HSL and MGL. Studies into how these lipases contribute to fat loss in cancer cachexia have revealed the prominent role for ATGL in initiating lipolysis during adipose tissue atrophy, together with links between tumour-derived factors and the signalling pathways that control lipid flux within fat cells. The recent findings of increased thermogenesis in brown fat during cancer cachexia indicate that metabolically active adipose tissue contributes to the imbalance in energy homeostasis involved in catabolic wasting. Such energetically futile use of fatty acids liberated from adipose tissue to generate heat represents a maladaptive response in conjunction with anorexia experienced by cancer patients. As IL-6 release by tumours provokes lipolysis and activates the thermogenic programme in brown fat, this review explores the overlap in dysregulated metabolic processes due to inflammatory mediators in cancer cachexia and other disease states characterised by elevated cytokines such as obesity and diabetes. PMID:26529279

  10. Browning attenuates murine white adipose tissue expansion during postnatal development.

    PubMed

    Lasar, D; Julius, A; Fromme, T; Klingenspor, M

    2013-05-01

    During postnatal development of mice distinct white adipose tissue depots display a transient appearance of brown-like adipocytes. These brite (brown in white) adipocytes share characteristics with classical brown adipocytes including a multilocular appearance and the expression of the thermogenic protein uncoupling protein 1. In this study, we compared two inbred mouse strains 129S6sv/ev and C57BL6/N known for their different propensity to diet-induced obesity. We observed transient browning in retroperitoneal and inguinal adipose tissue depots of these two strains. From postnatal day 10 to 20 the increase in the abundance of multilocular adipocytes and uncoupling protein 1 expression was higher in 129S6sv/ev than in C57BL6/N pups. The parallel increase in the mass of the two fat depots was attenuated during this browning period. Conversely, epididymal white and interscapular brown adipose tissue displayed a steady increase in mass during the first 30 days of life. In this period, 129S6sv/ev mice developed a significantly higher total body fat mass than C57BL6/N. Thus, while on a local depot level a high number of brite cells is associated with the attenuation of adipose tissue expansion the strain comparison reveals no support for a systemic impact on energy balance. This article is part of a Special Issue entitled Brown and White Fat: From Signaling to Disease. PMID:23376694