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Sample records for adipose tissue leptin

  1. 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

  2. Site-specific circadian expression of leptin and its receptor in human adipose tissue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Circadian variability of circulating leptin levels has been well established over the last decade. However, the circadian behavior of leptin in human adipose tissue remains unknown. This also applies to the soluble leptin receptor. We investigated the ex vivo circadian behavior of leptin and its rec...

  3. Anticontractile Effect of Perivascular Adipose Tissue and Leptin are Reduced in Hypertension

    PubMed Central

    Gálvez-Prieto, Beatriz; Somoza, Beatriz; Gil-Ortega, Marta; García-Prieto, Concha F.; de las Heras, Ana I.; González, M. Carmen; Arribas, Silvia; Aranguez, Isabel; Bolbrinker, Juliane; Kreutz, Reinhold; Ruiz-Gayo, Mariano; Fernández-Alfonso, Maria S.

    2012-01-01

    Leptin causes vasodilatation both by endothelium-dependent and -independent mechanisms. Leptin is synthesized by perivascular adipose tissue (PVAT). The hypothesis of this study is that a decrease of leptin production in PVAT of spontaneously hypertensive rats (SHR) might contribute to a diminished paracrine anticontractile effect of the hormone. We have determined in aorta from Wistar-Kyoto (WKY) and SHR (i) leptin mRNA and protein levels in PVAT, (ii) the effect of leptin and PVAT on contractile responses, and (iii) leptin-induced relaxation and nitric oxide (NO) production. Leptin mRNA and protein expression were significantly lower in PVAT from SHR. Concentration-response curves to angiotensin II were significantly blunted in presence of PVAT as well as by exogenous leptin (10−9 M) only in WKY. This anticontractile effect was endothelium-dependent. Vasodilatation induced by leptin was smaller in SHR than in WKY, and was also endothelium-dependent. Moreover, release of endothelial NO in response to acute leptin was higher in WKY compared to SHR, but completely abolished in the absence of endothelium. In conclusion, the reduced anticontractile effect of PVAT in SHR might be attributed to a reduced PVAT-derived leptin and to an abrogated effect of leptin on endothelial NO release probably due to an impaired activation of endothelial NO synthase. PMID:22679436

  4. Weight-dependent changes of immune system in adipose tissue: Importance of leptin

    SciTech Connect

    Caspar-Bauguil, S.; Cousin, B.; Andre, M.; Nibbelink, M.; Galinier, A.; Periquet, B.; Casteilla, L.; Penicaud, L. . E-mail: penicaud@toulouse.inserm.fr

    2006-07-15

    Ancestral lymphoid cells reside in adipose tissues, and their numbers are highly altered in obesity. Leptin, production of which is correlated to fat mass, is strongly involved in the relationships between adipose tissues and immune system. We investigated in epididymal (EPI) and inguinal (ING) fat pads to determine whether 1) lymphocyte phenotypes were correlated to the tissue weight and 2) leptin was involved in such relationships. Immunohistological analyses revealed a tight relationship between the T and NK lymphocytes of the stromal vascular fraction and adipocytes. We identified a significant negative and positive correlation between EPI weight and the percentage of NK and total T cells respectively by cytofluorometric analyses. The NK and ancestral {gamma}{delta} T cell contents were directly dependent of leptin since they increased significantly in high-fat (HF) diet mice but not in leptin-deficient (ob/ob) mice as compared to control. By contrast, the {alpha}{beta} T cell content seemed independent of leptin because their percentages increased significantly with the EPI weight whatever the type of mice (control, HF, ob/ob). The present study suggests that adipose tissues present, according to their localization, different immunological mechanisms that might be involved in the regulation of adipose cells functions and proliferations.

  5. Acute and chronic regulation of leptin synthesis, storage, and secretion by insulin and dexamethasone in human adipose tissue.

    PubMed

    Lee, Mi-Jeong; Wang, Yanxin; Ricci, Matthew R; Sullivan, Sean; Russell, Colleen D; Fried, Susan K

    2007-03-01

    Serum leptin levels are upregulated in proportion to body fat and also increase over the short term in response to meals or insulin. To understand the mechanisms involved, we assessed leptin synthesis and secretion in samples of adipose tissue from subjects with a wide range of BMI. Tissue leptin content and relative rates of leptin biosynthesis, as determined by metabolic labeling, were highly correlated with each other and with BMI and fat cell size. To understand mechanisms regulating leptin synthesis in obesity, we used biosynthetic labeling to directly assess the effects of insulin and glucocorticoids (dexamethasone) on leptin synthesis and secretion in human adipose tissue. Chronic treatment (1-2 days in organ culture) with insulin increased relative rates of leptin biosynthesis without affecting leptin mRNA levels. In contrast, dexamethasone increased leptin mRNA and biosynthesis in parallel. Acute treatment with insulin or dexamethasone (added during 1-h preincubation and 45-min pulse labeling) did not affect relative rates of leptin biosynthesis, but pulse-chase studies showed that addition of insulin nearly doubled the release of [35S]leptin after a 1-h chase. We conclude that the higher leptin stores in adipose tissue of obese humans are maintained by chronic effects of insulin and glucocorticoids acting at pre- and posttranslational levels and that the ability of insulin to increase the release of preformed leptin may contribute to short-term variations in circulating leptin levels. PMID:17122089

  6. Lipometer subcutaneous adipose tissue topography (SAT-Top) reflects serum leptin levels varying in circadian rhythms

    NASA Astrophysics Data System (ADS)

    Moeller, Reinhard; Tafeit, Erwin; Sudi, Karl; Vrecko, Karoline; Horejsi, Renate; Hinghofer-Szalkay, Helmut G.; Reibnegger, Gilbert

    1998-05-01

    Recent advances in obesity research have shown that the product of the ob-gene named leptin is related to total body fast mass in humans. There is, however, a debate if leptin levels are pulsatile and linked to body fat distribution. In this study we therefore investigated the subcutaneous adipose tissue topography (SAT-Top) measured by means of the newly developed device Lipometer and leptin levels during a 24 hours beginning at 0715am ending the same time in the next day. Blood samples for measurement of leptin were taken every 3 hours in a male subject. Measurements of SAT-Top were performed at 15 body sites from neck to calf at the left and right body site at the same time interval. We observed an almost symmetrically reaction of the left and right body site with a maximum of the mean value of all body sites in the evening at 0715pm. There was a negative correlation between serum leptin levels and SAT-Top using the set of certain body sites (R2 equals 0.80, p equals 0.01). If these combination of body sites is inversed and set against serum leptin levels, both curves show almost identical shape and time dependence. We conclude that SAT-Top by means of Lipometer is changed in a short time and related to leptin levels in the investigated male subject.

  7. Repeated electroacupuncture in obese Zucker diabetic fatty rats: adiponectin and leptin in serum and adipose tissue.

    PubMed

    Peplow, Philip V

    2015-04-01

    Fasted, male, obese, Zucker, diabetic fatty rats aged 10-16 weeks were anesthetized with 1% halothane in nitrous oxide-oxygen (3:1) on alternate weekdays over 2 weeks. Group 1 (n = 4) did not receive electroacupuncture (controls); Group 2 (n = 4) received electroacupuncture using the Zhongwan and the Guanyuan acupoints; Group 3 (n = 4) received electroacupuncture using the bilateral Zusanli acupoints; Group 4 (n = 6) received neither halothane in nitrous oxide:oxygen nor electroacupuncture. At the end of study, animals were injected with sodium pentobarbitone (60 mg/mL, i.p.), and blood and white adipose tissue were collected. Analysis of variance and Duncan's tests showed that the mean leptin in serum was significantly lower and the adiponectin:leptin ratio was significantly higher in Group 2 than in Group 1 (p < 0.05); for Group 4, the serum leptin was significantly higher than it was for Groups 1-3 (p < 0.05), and the adiponectin:leptin ratio was significantly lower than it was for Group 2 (p < 0.05). Similar changes occurred for the leptin levels in the pelvic adipose tissue. In addition, for Group 2, the mean serum insulin: glucose ratio was significantly higher than it was for Group 1 (p < 0.05); for Group 4 the mean serum insulin and insulin: glucose ratio were significantly higher than they were for Groups 1 and 3 (p < 0.05), but not Group 2 (p > 0.05). No significant differences in the serum or the adipose-tissue measurements between Groups 1 and 3 were observed (p > 0.05). PMID:25952122

  8. Adipose Tissue Promotes a Serum Cytokine Profile Related to Lower Insulin Sensitivity after Chronic Central Leptin Infusion

    PubMed Central

    Burgos-Ramos, Emma; Canelles, Sandra; Perianes-Cachero, Arancha; Arilla-Ferreiro, Eduardo; Argente, Jesús; Barrios, Vicente

    2012-01-01

    Obesity is an inflammatory state characterized by an augment in circulating inflammatory factors. Leptin may modulate the synthesis of these factors by white adipose tissue decreasing insulin sensitivity. We have examined the effect of chronic central administration of leptin on circulating levels of cytokines and the possible relationship with cytokine expression and protein content as well as with leptin and insulin signaling in subcutaneous and visceral adipose tissues. In addition, we analyzed the possible correlation between circulating levels of cytokines and peripheral insulin resistance. We studied 18 male Wistar rats divided into controls (C), those treated icv for 14 days with a daily dose of 12 μg of leptin (L) and a pair-fed group (PF) that received the same food amount consumed by the leptin group. Serum leptin and insulin were measured by ELISA, mRNA levels of interferon-γ (IFN-γ), interleukin-2 (IL-2), IL-4, IL-6, IL-10 and tumor necrosis factor-α (TNF-α) by real time PCR and serum and adipose tissue levels of these cytokines by multiplexed bead immunoassay. Serum leptin, IL-2, IL-4, IFN-γ and HOMA-IR were increased in L and TNF-α was decreased in PF and L. Serum leptin and IL-2 levels correlate positively with HOMA-IR index and negatively with serum glucose levels during an ip insulin tolerance test. In L, an increase in mRNA levels of IL-2 was found in both adipose depots and IFN-γ only in visceral tissue. Activation of leptin signaling was increased and insulin signaling decreased in subcutaneous fat of L. In conclusion, leptin mediates the production of inflammatory cytokines by adipose tissue independent of its effects on food intake, decreasing insulin sensitivity. PMID:23056516

  9. Telmisartan Ameliorates Nephropathy in Metabolic Syndrome by Reducing Leptin Release From Perirenal Adipose Tissue.

    PubMed

    Li, Hao; Li, Min; Liu, Ping; Wang, YaPing; Zhang, Heng; Li, HongBin; Yang, ShiFeng; Song, Yan; Yin, YanRong; Gao, Lan; Cheng, Si; Cai, Jun; Tian, Gang

    2016-08-01

    Metabolic syndrome (MetS) is associated with nephropathy. Along with common risk factors such as hypertension and hyperglycemia, adipocytokines released from perirenal adipose tissue (PRAT) are implicated in the pathogenesis of MetS nephropathy. The study was designed to elucidate the adverse effects of PRAT-derived leptin on nephropathy and to determine whether the angiotensin II type 1 receptor antagonist telmisartan exerts a renoprotective effect by decreasing the PRAT-derived leptin level in the high-fat diet-induced MetS rat. In MetS rats, PRAT-derived leptin expression increased concomitant with dysfunction of adipogenesis, and the activities of the angiotensin II-angiotensin II type 1 receptor and the angiotensin-converting enzyme 2-angiotensin (1-7)-Mas receptor axes were imbalanced in PRAT. PRAT-derived leptin from MetS rats promoted proliferation of rat glomerular endothelial cells (GERs) by activating the p38 MAPK (mitogen-activated protein kinase) pathway, thereby contributing to the development of nephropathy. Long-term telmisartan treatment improved metabolic parameters and renal function, decreased the amount of PRAT, promoted adipogenesis, increased the expression of angiotensin-converting enzyme 2, restored balanced activities of the angiotensin II-AT1R and angiotensin-converting enzyme 2-angiotensin (1-7)-Mas axes, and exerted an indirect renoprotective effect on MetS rats by decreasing PRAT-derived leptin release. Our results demonstrate a novel link between nephropathy and PRAT in MetS and show that telmisartan confers an underlying protective effect on visceral adipose tissue and the kidney, suggesting that it has potential as a therapeutic agent for the treatment of MetS-associated nephropathy. PMID:27296996

  10. Bone Marrow Leptin Signaling Mediates Obesity-Associated Adipose Tissue Inflammation in Male Mice

    PubMed Central

    Dib, Lea H.; Ortega, M. Teresa; Fleming, Sherry D.; Melgarejo, Tonatiuh

    2014-01-01

    Obesity is characterized by an increased recruitment of proinflammatory macrophages to the adipose tissue (AT), leading to systemic inflammation and metabolic disease. The pathogenesis of this AT inflammation, however, remains to be elucidated. The circulating adipokine leptin is increased in obesity and is involved in immune cell function and activation. In the present study, we investigated the role of leptin in the induction of obesity-associated inflammation. We generated radiation chimeric C57BL/6J mice reconstituted with either leptin receptor-deficient (db/db) or wild-type (WT) bone marrow and challenged them with a high-fat diet (HFD) for 16 weeks. Mice reconstituted with db/db bone marrow (WT/db), had significantly lower body weight and adiposity compared with mice with WT bone marrow (WT/WT). Gonadal AT in WT/db mice displayed a 2-fold lower expression of the inflammatory genes Tnfa, Il6, and Ccl2. In addition, gonadal fat of WT/db mice contained significantly fewer crown-like structures compared with WT/WT mice, and most of their AT macrophages expressed macrophage galactose-type C type lectin 1 (MGL1) and were C-C chemokine receptor type 2 (CCR2)-negative, indicative of an anti-inflammatory phenotype. Moreover, WT/db mice exhibited greater insulin sensitivity compared with WT/WT mice. These data show that disrupted leptin signaling in bone marrow-derived cells attenuates the proinflammatory conditions that mediate many of the metabolic complications that characterize obesity. Our findings establish a novel mechanism involved in the regulation of obesity-associated systemic inflammation and support the hypothesis that leptin is a proinflammatory cytokine. PMID:24169547

  11. Mimecan, a Hormone Abundantly Expressed in Adipose Tissue, Reduced Food Intake Independently of Leptin Signaling

    PubMed Central

    Cao, Huang-Ming; Ye, Xiao-Ping; Ma, Jun-Hua; Jiang, He; Li, Sheng-Xian; Li, Rong-Ying; Li, Xue-Song; Guo, Cui-Cui; Wang, Zhi-Quan; Zhan, Ming; Zuo, Chun-Lin; Pan, Chun-Ming; Zhao, Shuang-Xia; Zheng, Cui-Xia; Song, Huai-Dong

    2015-01-01

    Adipokines such as leptin play important roles in the regulation of energy metabolism, particularly in the control of appetite. Here, we describe a hormone, mimecan, which is abundantly expressed in adipose tissue. Mimecan was observed to inhibit food intake and reduce body weight in mice. Intraperitoneal injection of a mimecan-maltose binding protein (-MBP) complex inhibited food intake in C57BL/6J mice, which was attenuated by pretreatment with polyclonal antibody against mimecan. Notably, mimecan-MBP also induced anorexia in Ay/a and db/db mice. Furthermore, the expression of interleukin (IL)-1β and IL-6 was up-regulated in the hypothalamus by mimecan-MBP, as well as in N9 microglia cells by recombinant mouse mimecan. Taken together, the results suggest that mimecan is a satiety hormone in adipose tissue, and that mimecan inhibits food intake independently of leptin signaling by inducing IL-1β and IL-6 expression in the hypothalamus. PMID:26870797

  12. Inhibin betaB expression in murine adipose tissue and its regulation by leptin, insulin and dexamethasone.

    PubMed

    Hoggard, N; Cruickshank, M; Moar, K M; Barrett, P; Bashir, S; Miller, J D B

    2009-10-01

    Inhibin betaB (INHBB; coding for the activin betaB subunit) has previously been identified in both human and rodent adipose tissue and using Taqman real-time PCR with specific primers we confirm the expression of INHBB mRNA in rodent adipose tissue. Expression of INHBB in murine epididymal adipose tissue was higher than in any of the other tissues studied and appears to be regulated by changes in energy balance and leptin. It was increased fourfold in the epididymal fat depot of ob/ob mice compared with the same fat depot in lean mice. The i.p. administration of leptin in obese ob/ob mice decreases the expression of INHBB. In human adipose tissue, INHBB is reduced by weight loss. In keeping with this, we demonstrate that INHBB expression in murine adipose tissue is decreased in fasting and increased upon refeeding. We show that INHBB is expressed in both the mature adipocyte and the stromal vascular fraction of adipose tissue. INHBB increases with the differentiation of pre-adipocytes into mature adipocytes in the 3T3-L1 cell line. In differentiated 3T3-L1 adipocytes, where receptors to activin have been previously reported, insulin increases the expression of INHBB, while dexamethasone decreases the expression of INHBB when compared with untreated control cells. Taken together, these results suggest that the regulation of INHBB expression in adipose tissue may play a physiological role in energy balance or the insulin insensitivity associated with obesity. PMID:19491194

  13. TUMOR NECROSIS FACTOR ALPHA AND GLUCOCORTICOID SYNERGISTICALLY INCREASE LEPTIN PRODUCTION IN HUMAN ADIPOSE TISSUE: ROLE FOR P38 MITOGEN-ACTIVATED PROTEIN KINASE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    TNF increases plasma leptin in humans in vivo, but previous studies showed it decreases leptin in vitro. The objective of this study was to determine the effect of TNF on leptin release from human adipose tissue (AT) from healthy subjects undergoing elective surgery or needle aspirations of AT at a ...

  14. Direct in vitro effects of androgens and estrogens on ob gene expression and leptin secretion in human adipose tissue.

    PubMed

    Machinal-Quélin, Florence; Dieudonné, Marie-Noëlle; Pecquery, René; Leneveu, Marie-Christine; Giudicelli, Yves

    2002-07-01

    In the present study, we have explored, in vitro, the possibility that short exposure to androgens and estrogens for 24 h may directly influence leptin expression (ARNm and secretion) in sc adipose tissue from men and women. In men, only dihydrotestosterone at high concentration (100 nM) induced a reduction in leptin secretion and ob mRNA level. In women, 17beta-estradiol (10-100 nM) increased ob mRNA expression (+180 to +500%) and leptin release (+75%). Moreover, in adipose tissue of women, the estrogen precursors testosterone (100 nM) and dehydroepiandrosterone (1 microM) also induced an increase in leptin secretion (+84 and +96%, respectively), an effect that was prevented by the aromatase inhibitor letrozole. Finally, the stimulatory effect of 17beta-estradiol observed in women was antagonized by the antiestrogen ICI182780. Altogether, these results suggest that the sexual dimorphism of leptinemia in humans is mainly owing to the estrogen receptor-dependent stimulation of leptin expression in adipose tissue by estrogens and estrogen precursors in women. PMID:12374466

  15. Role of obesity and adipose tissue-derived cytokine leptin during Clostridium difficile infection

    PubMed Central

    Madan, Rajat; Petri, William A.

    2015-01-01

    Obesity is among the most pressing health concerns in the world since it is increasingly common even in the developing world, and is clearly associated with increased risk for chronic debilitating diseases and death. Furthermore, obesity can influence the pathogenesis of infectious diseases by affecting the balance of pathogen clearance and pathological inflammation. The mechanisms that result in enhanced inflammation in obese individuals are poorly understood. Clostridium difficile is a major cause of nosocomial infections worldwide. Recent studies have shown that obesity is associated with increased risk of C. difficile infections. In this review, we will discuss our current knowledge of the role of obesity in determining risk of C. difficile infections, and focus on the role of the adipose tissue-derived cytokine leptin in C. difficile infections. PMID:25638400

  16. Role of obesity and adipose tissue-derived cytokine leptin during Clostridium difficile infection.

    PubMed

    Madan, Rajat; Petri, William A

    2015-08-01

    Obesity is among the most pressing health concerns in the world since it is increasingly common even in the developing world, and is clearly associated with increased risk for chronic debilitating diseases and death. Furthermore, obesity can influence the pathogenesis of infectious diseases by affecting the balance of pathogen clearance and pathological inflammation. The mechanisms that result in enhanced inflammation in obese individuals are poorly understood. Clostridium difficile is a major cause of nosocomial infections worldwide. Recent studies have shown that obesity is associated with increased risk of C. difficile infections. In this review, we will discuss our current knowledge of the role of obesity in determining risk of C. difficile infections, and focus on the role of the adipose tissue-derived cytokine leptin in C. difficile infections. PMID:25638400

  17. Leptin of dermal adipose tissue is differentially expressed during the hair cycle and contributes to adipocyte-mediated growth inhibition of anagen-phase vibrissa hair.

    PubMed

    Yang, Chao-Chun; Sheu, Hamm-Ming; Chung, Pei-Lun; Chang, Chung-Hsing; Tsai, Yau-Sheng; Hughes, Michael W; Tuan, Tai-Lan; Huang, Lynn L H

    2015-01-01

    Adipose tissue encircles the lower portion of anagen hair follicles and may regulate hair cycle progression. As leptin is a major adipokine, its level of expression from the dermal white adipose tissue during hair cycle progression was studied. The result shows that leptin level is differentially expressed during hair cycle, the lowest in early anagen phase, upregulated in late anagen phase and the highest in the telogen phase. On the other hand, leptin receptor is detected in keratin 15-positive hair bulge epithelium of both anagen- and telogen-phase hair follicles of mice pelage and vibrissa hair, and hair from human scalp. Leptin contributes to adipocyte-mediated growth inhibition of anagen-phase vibrissa hair as demonstrated in organ culture and coculture system. Our data suggest that leptin of dermal white adipose tissue might regulate hair growth and, therefore, hair cycle progression via leptin receptor on the hair follicle epithelium. PMID:25313970

  18. Endurance training increases leptin expression in the retroperitoneal adipose tissue of rats fed with a high-sugar diet.

    PubMed

    de Queiroz, Karina Barbosa; Guimarães, Juliana Bohnen; Coimbra, Cândido Celso; Rodovalho, Gisele Vieira; Carneiro, Cláudia Martins; Evangelista, Elísio Alberto; Guerra-Sá, Renata

    2014-01-01

    The presence of leptin receptors in white adipose tissue (WAT) suggests a type of peripheral control during the development of obesity and other metabolic disorders. Both diet composition and exercise influence serum leptin; however, the effect of their combination on long-term WAT leptin metabolism is unknown. In this study, rats fed with standard or high-sugar diets (HSD) were simultaneously subjected to running training for 4- and 8-week periods, and the retroperitoneal WAT (rWAT) was evaluated for adipocyte cell size, lipid and catecholamine content, Lep, OB-Rb and Ucp2 mRNA transcription levels, and circulating leptin and non-esterified fatty acids (NEFA). The HSD groups displayed a higher adiposity index and rWAT weight, Lep mRNA and protein upregulation, and a period-dependent effect on OB-Rb mRNA expression. Exercise decreased serum leptin and upregulated the OB-Rb mRNA levels. However, in rats fed with an HSD, the increase in OB-Rb mRNA and reduction in catecholamine levels resulted in a high level of adiposity and hyperleptinemia. The combination of training and an HSD decreases the NEFA levels and upregulating the Ucp2 mRNA expression in the 4-week period, while downregulating the Ucp2 mRNA expression in the 8-week period without changing the NEFA levels. Our results suggest that an HSD induces an increase in leptin expression in rWAT, while reducing adipocytes via leptin-mediated lipolysis after an 8-week period. In exercised rats fed an HSD, TAG synthesis and storage overlaps with lipolysis, promoting fat store development and Lep mRNA and plasma protein upregulation in adult rats. PMID:24243000

  19. Salidroside improves glucose homeostasis in obese mice by repressing inflammation in white adipose tissues and improving leptin sensitivity in hypothalamus

    PubMed Central

    Wang, Meihong; Luo, Lan; Yao, Lili; Wang, Caiping; Jiang, Ketao; Liu, Xiaoyu; Xu, Muchen; Shen, Ningmei; Guo, Shaodong; Sun, Cheng; Yang, Yumin

    2016-01-01

    Salidroside is a functionally versatile natural compound from the perennial flowering plant Rhodiola rosea L. Here, we examined obese mice treated with salidroside at the dosage of 50 mg/kg/day for 48 days. Mice treated with salidroside showed slightly decreased food intake, body weight and hepatic triglyceride content. Importantly, salidroside treatment significantly improved glucose and insulin tolerance. It also increased insulin singling in both liver and epididymal white adipose tissue (eWAT). In addition, salidroside markedly ameliorated hyperglycemia in treated mice, which is likely due to the suppression of gluconeogenesis by salidroside as the protein levels of a gluconeogenic enzyme G6Pase and a co-activator PGC-1α were all markedly decreased. Further analysis revealed that adipogenesis in eWAT was significantly decreased in salidroside treated mice. The infiltration of macrophages in eWAT and the productions of pro-inflammatory cytokines were also markedly suppressed by salidroside. Furthermore, the leptin signal transduction in hypothalamus was improved by salidroside. Taken together, these euglycemic effects of salidroside may due to repression of adipogenesis and inflammation in eWAT and stimulation of leptin signal transduction in hypothalamus. Thus, salidroside might be used as an effective anti-diabetic agent. PMID:27145908

  20. Salidroside improves glucose homeostasis in obese mice by repressing inflammation in white adipose tissues and improving leptin sensitivity in hypothalamus.

    PubMed

    Wang, Meihong; Luo, Lan; Yao, Lili; Wang, Caiping; Jiang, Ketao; Liu, Xiaoyu; Xu, Muchen; Shen, Ningmei; Guo, Shaodong; Sun, Cheng; Yang, Yumin

    2016-01-01

    Salidroside is a functionally versatile natural compound from the perennial flowering plant Rhodiola rosea L. Here, we examined obese mice treated with salidroside at the dosage of 50 mg/kg/day for 48 days. Mice treated with salidroside showed slightly decreased food intake, body weight and hepatic triglyceride content. Importantly, salidroside treatment significantly improved glucose and insulin tolerance. It also increased insulin singling in both liver and epididymal white adipose tissue (eWAT). In addition, salidroside markedly ameliorated hyperglycemia in treated mice, which is likely due to the suppression of gluconeogenesis by salidroside as the protein levels of a gluconeogenic enzyme G6Pase and a co-activator PGC-1α were all markedly decreased. Further analysis revealed that adipogenesis in eWAT was significantly decreased in salidroside treated mice. The infiltration of macrophages in eWAT and the productions of pro-inflammatory cytokines were also markedly suppressed by salidroside. Furthermore, the leptin signal transduction in hypothalamus was improved by salidroside. Taken together, these euglycemic effects of salidroside may due to repression of adipogenesis and inflammation in eWAT and stimulation of leptin signal transduction in hypothalamus. Thus, salidroside might be used as an effective anti-diabetic agent. PMID:27145908

  1. Angiotensin type 1a receptors in the forebrain subfornical organ facilitate leptin-induced weight loss through brown adipose tissue thermogenesis

    PubMed Central

    Young, Colin N.; Morgan, Donald A.; Butler, Scott D.; Rahmouni, Kamal; Gurley, Susan B.; Coffman, Thomas M.; Mark, Allyn L.; Davisson, Robin L.

    2015-01-01

    Objective Elevations in brain angiotensin-II cause increased energy expenditure and a lean phenotype. Interestingly, the metabolic effects of increased brain angiotensin-II mimic the actions of leptin, suggesting an interaction between the two systems. Here we demonstrate that angiotensin-type 1a receptors (AT1aR) in the subfornical organ (SFO), a forebrain structure emerging as an integrative metabolic center, play a key role in the body weight-reducing effects of leptin via brown adipose tissue (BAT) thermogenesis. Methods Cre/LoxP technology coupled with targeted viral delivery to the SFO in a mouse line bearing a conditional allele of the Agtr1a gene was utilized to determine the interaction between leptin and SFO AT1aR in metabolic regulation. Results Selective deletion of AT1aR in the SFO attenuated leptin-induced weight loss independent of changes in food intake or locomotor activity. This was associated with diminished leptin-induced increases in core body temperature, blunted upregulation of BAT thermogenic markers, and abolishment of leptin-mediated sympathetic activation to BAT. Conclusions These data identify a novel interaction between angiotensin-II and leptin in the control of BAT thermogenesis and body weight, and highlight a previously unrecognized role for the forebrain SFO in metabolic regulation. PMID:25830096

  2. Cardiomyocyte Antihypertrophic Effect of Adipose Tissue Conditioned Medium from Rats and Its Abrogation by Obesity is Mediated by the Leptin to Adiponectin Ratio

    PubMed Central

    Bairwa, Suresh C.; Rajapurohitam, Venkatesh; Gan, Xiaohong Tracey; Mangat, Rabban; Proctor, Spencer D.; Karmazyn, Morris

    2016-01-01

    White adipocytes are known to function as endocrine organs by secreting a plethora of bioactive adipokines which can regulate cardiac function including the development of hypertrophy. We determined whether adipose tissue conditioned medium (ATCM) generated from the epididymal regions of normal rats can affect the hypertrophic response of cultured rat ventricular myocytes to endothelin-1 (ET-1) administration. Myocytes were treated with ET-1 (10 nM) for 24 hours in the absence or presence of increasing ATCM concentrations. ATCM supressed the hypertrophic response to ET-1 in a concentration-dependent manner, an effect enhanced by the leptin receptor antagonist and attenuated by an antibody against the adiponectin AdipoR1 receptor. Antihypertrophic effects were also observed with ATCM generated from perirenal-derived adipose tissue. However, this effect was absent in ATCM from adipose tissue harvested from corpulent JCR:LA-cp rats. Detailed analyses of adipokine content in ATCM from normal and corpulent rats revealed no differences in the majority of products assayed, although a significant increase in leptin concentrations concomitant with decreased adiponectin levels was observed, resulting in a 11 fold increase in the leptin to adiponectin ratio in ATCM from JCR:LA-cp. The antihypertrophic effect of ATCM was associated with increased phosphorylation of AMP-activated protein kinase (AMPK), an effect abrogated by the AdipoR1 antibody. Moreover, the antihypertrophic effect of ATCM was mimicked by an AMPK activator. There was no effect of ET-1 on mitogen-activated protein kinase (MAPK) activities 24 hour after its addition either in the presence or absence of ATCM. Our study suggests that adipose tissue from healthy subjects exerts antihypertrophic effects via an adiponectin–dependent pathway which is impaired in obesity, most likely due to adipocyte remodelling resulting in enhanced leptin and reduced adiponectin levels. PMID:26731409

  3. Leptin Receptor Expressing Neurons in the Dorsomedial Hypothalamus and Median Preoptic Area Regulate Sympathetic Brown Adipose Tissue Circuits

    PubMed Central

    Zhang, Yan; Kerman, Ilan A.; Laque, Amanda; Nguyen, Phillip; Faouzi, Miro; Louis, Gwendolyn W.; Jones, Justin C.; Rhodes, Chris; Münzberg, Heike

    2011-01-01

    Brown adipose tissue (BAT) thermogenesis is critical to maintain homoeothermia and is centrally controlled via sympathetic outputs. Body temperature and BAT activity also impact energy expenditure and obesity is commonly associated with decreased BAT capacity and sympathetic tone. Severely obese mice that lack leptin or its receptor (LepRb) show decreased BAT capacity, sympathetic tone and body temperature, and thus are unable to adapt to acute cold exposure (Trayhurn et al., 1976). LepRb expressing neurons are found in several hypothalamic sites including the dorsomedial hypothalamus (DMH) and median preoptic area (mPOA), both critical sites to regulate sympathetic, thermoregulatory BAT circuits. Specifically, a subpopulation in the DMH/dorsal hypothalamic area (DMH/DHA) is stimulated by fever inducing endotoxins or cold exposure (Dimicco and Zaretsky, 2007;Morrison et al., 2008). Using the retrograde, transsynaptic tracer pseudorabies virus (PRV) injected into the BAT of mice we identified PRV labeled LepRb neurons in the DMH/DHA and mPOA (and other sites), thus indicating their involvement in the regulation of sympathetic BAT circuits. Indeed, acute cold exposure induced cFos (as a surrogate for neuronal activity) in DMH/DHA LepRb neurons, and a large number of mPOA LepRb neurons project to the DMH/DHA. Furthermore, DMH/DHA LepRb neurons (and a subpopulation of LepRb mPOA neurons) project and synaptically couple to rostral raphe pallidus neurons, consistent with the current understanding of BAT thermoregulatory circuits from the DMH/DHA and mPOA (Dimicco and Zaretsky, 2007;Morrison et al., 2008). Thus, these data present strong evidence that LepRb neurons in the DMH/DHA and mPOA mediate thermoregulatory leptin action. PMID:21289197

  4. Placental restriction of fetal growth decreases IGF1 and leptin mRNA expression in the perirenal adipose tissue of late gestation fetal sheep.

    PubMed

    Duffield, Jaime A; Vuocolo, Tony; Tellam, Ross; Yuen, Bernard S; Muhlhausler, Beverly S; McMillen, I Caroline

    2008-05-01

    Placental restriction (PR) of fetal growth results in a low birth weight and an increased visceral fat mass in postnatal life. We investigated whether PR alters expression of genes that regulate adipogenesis [IGF1, IGF1 receptor (IGF1R), IGF2, IGF2R, proliferator-activated receptor-gamma, retinoid-X-receptor-alpha], adipocyte metabolism (lipoprotein lipase, G3PDH, GAPDH) and adipokine signaling (leptin, adiponectin) in visceral adipose tissue before birth. PR was induced by removal of the majority of endometrial caruncles in nonpregnant ewes before mating. Fetal blood samples were collected from 116 days gestation, and perirenal visceral adipose tissue (PAT) was collected from PR and control fetuses at 145 days. PAT gene expression was measured by quantitative RT-PCR. PR fetuses had a lower weight (PR 2.90 +/- 0.32 kg; control, 5.12 +/- 0.24 kg; P < 0.0001), mean gestational arterial Po(2) (P < 0.0001), plasma glucose (P < 0.01), and insulin concentrations (P < 0.02), than controls. The expression of IGF1 mRNA in PAT was lower in the PR fetuses (PR, 0.332 +/- 0.063; control, 0.741 +/- 0.083; P < 0.01). Leptin mRNA expression in PAT was also lower in PR fetuses (PR, 0.077 +/- 0.009; control, 0.115 +/- 0.013; P < 0.05), although there was no difference in the expression of other adipokine or adipogenic genes in PAT between PR and control fetuses. Thus, restriction of placental and hence, fetal substrate supply results in decreased IGF1 and leptin expression in fetal visceral adipose tissue, which may alter the functional development of the perirenal fat depot and contribute to altered leptin signaling in the growth-restricted newborn and the subsequent emergence of an increased visceral adiposity. PMID:18272661

  5. Role of Exchange Protein Directly Activated by Cyclic AMP Isoform 1 in Energy Homeostasis: Regulation of Leptin Expression and Secretion in White Adipose Tissue.

    PubMed

    Hu, Yaohua; Robichaux, William G; Mei, Fang C; Kim, Eun Ran; Wang, Hui; Tong, Qingchun; Jin, Jianping; Xu, Mingxuan; Chen, Ju; Cheng, Xiaodong

    2016-10-01

    Epacs (exchange proteins directly activated by cyclic AMP [cAMP]) act as downstream effectors of cAMP and play important roles in energy balance and glucose homeostasis. While global deletion of Epac1 in mice leads to heightened leptin sensitivity in the hypothalamus and partial protection against high-fat diet (HFD)-induced obesity, the physiological functions of Epac1 in white adipose tissue (WAT) has not been explored. Here, we report that adipose tissue-specific Epac1 knockout (AEKO) mice are more prone to HFD-induced obesity, with increased food intake, reduced energy expenditure, and impaired glucose tolerance. Despite the fact that AEKO mice on HFD display increased body weight, these mice have decreased circulating leptin levels compared to their wild-type littermates. In vivo and in vitro analyses further reveal that suppression of Epac1 in WAT decreases leptin mRNA expression and secretion by inhibiting cAMP response element binding (CREB) protein and AKT phosphorylation, respectively. Taken together, our results demonstrate that Epac1 plays an important role in regulating energy balance and glucose homeostasis by promoting leptin expression and secretion in WAT. PMID:27381457

  6. In vivo and ex vivo regulation of visfatin production by leptin in human and murine adipose tissue: role of mitogen-activated protein kinase and phosphatidylinositol 3-kinase signaling pathways.

    PubMed

    Tan, Bee K; Chen, Jing; Brown, James; Adya, Raghu; Ramanjaneya, Manjunath; Menon, Vinod; Bailey, Clifford J; Lehnert, Hendrik; Randeva, Harpal S

    2009-08-01

    Visfatin is an adipogenic adipokine with increased levels in obesity, properties common to leptin. Thus, leptin may modulate visfatin production in adipose tissue (AT). Therefore, we investigated the effects of leptin on visfatin levels in 3T3-L1 adipocytes and human/murine AT, with or without a leptin antagonist. The potential signaling pathways and mechanisms regulating visfatin production in AT was also studied. Real-time RT-PCR and Western blotting were used to assess the relative mRNA and protein expression of visfatin. ELISA was performed to measure visfatin levels in conditioned media of AT explants, and small interfering RNA technology was used to reduce leptin receptor expression. Leptin significantly (P < 0.01) increased visfatin levels in human and murine AT with a maximal response at leptin 10(-9) M, returning to baseline at leptin 10(-7) M. Importantly, ip leptin administration to C57BL/6 ob/ob mice further supported leptin-induced visfatin protein production in omental AT (P < 0.05). Additionally, soluble leptin receptor levels rose with concentration dependency to a maximal response at leptin 10(-7) M (P < 0.01). The use of a leptin antagonist negated the induction of visfatin and soluble leptin receptor by leptin. Furthermore, leptin-induced visfatin production was significantly decreased in the presence of MAPK and phosphatidylinositol 3-kinase inhibitors. Also, when the leptin receptor gene was knocked down using small interfering RNA, leptin-induced visfatin expression was significantly decreased. Thus, leptin increases visfatin production in AT in vivo and ex vivo via pathways involving MAPK and phosphatidylinositol 3-kinase signaling. The pleiotropic effects of leptin may be partially mediated by visfatin. PMID:19389835

  7. Expression of interleukins, neuropeptides, and growth hormone receptor and leptin receptor genes in adipose tissue from growing broiler chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 quantitative real-time PCR analysis. Studies of the gene expression of cytokines and associated genes in chicken adipose tissue were initia...

  8. 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...

  9. Circulating ghrelin and leptin concentrations and growth hormone secretagogue receptor abundance in liver, muscle, and adipose tissue of beef cattle exhibiting differences in composition of gain.

    PubMed

    Jennings, J S; Wertz-Lutz, A E; Pritchard, R H; Weaver, A D; Keisler, D H; Bruns, K

    2011-12-01

    Data from species other than cattle indicate that ghrelin and GH secretagogue receptor (GHS-R) could play a key role in fat deposition, energy homeostasis, or glucose metabolism by directly affecting liver and adipose tissue metabolism. Beef steers (n = 72) were used to test the hypothesis that plasma ghrelin and leptin concentrations and abundance of the GHS-R in liver, muscle, and adipose tissues differ in steers exhibiting differences in composition of gain. At trial initiation (d 0), 8 steers were slaughtered for initial carcass composition. The remaining 64 steers were stratified by BW, allotted to pen, and treatment was assigned randomly to pen. Steers were not implanted with anabolic steroids. Treatments were 1) a low-energy (LE) diet fed during the growing period (0 to 111 d) followed by a high-energy (HE) diet during the finishing period (112 to 209 d; LE-HE) or 2) the HE diet for the duration of the trial (1 to 209 d; HE-HE). Eight steers per treatment were slaughtered on d 88, 111, 160, and 209. Carcass ninth, tenth, and eleventh rib sections were dissected for chemical composition and regression equations were developed to predict compositional gain. Liver, muscle, and subcutaneous adipose tissues were frozen in liquid nitrogen for subsequent Western blotting for GHS-R. Replicate blood samples collected before each slaughter were assayed for ghrelin and leptin concentrations. When compared at a common compositional fat end-point, the rate of carcass fat accretion (g·kg of shrunk BW(-1)) was greater (P < 0.001) in HE-HE steers whereas the rate of carcass protein accretion (g·kg of shrunk BW(-1)) was less (P < 0.001) compared with LE-HE steers. When compared at a common compositional fat end-point, plasma leptin, ghrelin, and insulin concentrations were greater (P < 0.05) for HE-HE compared with LE-HE steers. Abundance of the GHS-R, to which ghrelin binds, increased over time in liver and adipose tissue but did not differ as a result of treatment

  10. Subcutaneous adipose tissue topography (SAT-Top) by means of the optical device lipometer highly correlated to plasma leptin levels in obese boys

    NASA Astrophysics Data System (ADS)

    Sudi, Karl; Moeller, Reinhard; Tafeit, Erwin; Reiterer, Elke; Borkenstein, Martin; Vrecko, Karoline; Horejsi, Renate; Reibnegger, Gilbert; Hofmann, Peter

    1998-05-01

    The product of the ob-gene named leptin is correlated with body fat mass in humans. Little evidence exists if the same holds true for body fat distribution. In this study we therefore investigated plasma leptin levels and the subcutaneous adipose tissue topography (SAT-Top) by means of the newly developed optical device Lipometer before and after a 3 week weight reduction camp. Thirty four obese boys (mean age 12a) took part in this study. Body fat distribution were assessed by means of Lipometer to measure the thickness of a subcutaneous fat layer at 15 standardized body sites (SAT- Top). Plasma leptin levels (LL) were measured by radioimmunoassay. All measurements were taken at the beginning and at the end of the camp. By dividing all boys according chronological age (group A: age less than 12a, n equals 17/group B: greater than 12a, n equals 17) we found correlations with the combination of measured body sites (MBS) before (A: MBS vs. LL, R2 equals 0.79; p less than 0.01/B: MBS vs. LL, R2 equals 0.35; n.s.) and after (A: MBS vs. LL, R2 equals 0.83; p less than 0.01/B: MBS vs. LL, R2 equals 0.70; p less than 0.01) the intervention. Our study confirms that the subcutaneous adipose tissue topography (SAT- Top) by means of the optical device Lipometer serves as a marker of plasma leptin levels in obese boys and highlights the use of this optical device in a predictive manner.

  11. 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

  12. Leptin differentially regulates STAT3 activation in the ob/ob mice adipose mesenchymal stem cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leptin-deficient genetically obese ob/ob mice exhibit adipocyte hypertrophy and hyperplasia as well as elevated adipose tissue and systemic inflammation. Studies have shown that multipotent stem cells isolated from adult adipose tissue can differentiate into adipocytes ex vivo and thereby contribute...

  13. Hypothalamic PKA regulates leptin sensitivity and adiposity

    PubMed Central

    Yang, Linghai; McKnight, G. Stanley

    2015-01-01

    Mice lacking the RIIβ regulatory subunit of cyclic AMP-dependent protein kinase A (PKA) display reduced adiposity and resistance to diet-induced obesity. Here we show that RIIβ knockout (KO) mice have enhanced sensitivity to leptin's effects on both feeding and energy metabolism. After administration of a low dose of leptin, the duration of hypothalamic JAK/STAT3 signalling is increased, resulting in enhanced POMC mRNA induction. Consistent with the extended JAK/STAT3 activation, we find that the negative feedback regulator of leptin receptor signalling, Socs3, is inhibited in the hypothalamus of RIIβ KO mice. During fasting, RIIβ–PKA is activated and this correlates with an increase in CREB phosphorylation. The increase in CREB phosphorylation is absent in the fasted RIIβ KO hypothalamus. Selective inhibition of PKA activity in AgRP neurons partially recapitulates the leanness and resistance to diet-induced obesity of RIIβ KO mice. Our findings suggest that RIIβ–PKA modulates the duration of leptin receptor signalling and therefore the magnitude of the catabolic response to leptin. PMID:26381935

  14. 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

  15. Does leptin signal adiposity in the egg-laying mammal, Tachyglossus aculeatus?

    PubMed

    Sprent, Jenny; Jones, Susan M; Nicol, Stewart C

    2012-09-01

    Leptin is a peptide hormone best known for its role in feedback regulation of adiposity in eutherian mammals. Normally an increase in adipose tissue mass leads to an increase in circulating leptin which increases energy expenditure and limits food intake, but in hibernating eutherian mammals this relationship may change to allow prehibernatory fattening. The echidna (Tachyglossus aculeatus) is a monotreme mammal which accumulates significant fat reserves before entering hibernation, and mates immediately at the end of hibernation. We hypothesised that echidnas would show a strong relationship between body mass and plasma leptin for most of the year which would change during the pre-hibernatory period. We measured plasma leptin and body mass in free-ranging echidnas over several reproductive and hibernation cycles. There were significant seasonal variations in plasma leptin in both sexes, with the highest levels occurring in hibernation and in mating females. The lowest levels were found in males when they were foraging maximally after the reproductive period. We used mass%, body mass at the time of sampling as a percentage of long term mean mass, as a proxy for adiposity. There was a weak negative relationship between mass% and plasma leptin, from which we infer a weak negative relationship between adiposity and plasma leptin as has been found in reptiles and birds, rather than the strong positive relationship found in other mammals. PMID:22750512

  16. 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

  17. 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

  18. Expression of interleukins, neuropeptides, and growth hormone receptor (GHR) and leptin receptor (LPR) genes in adipose tissue from growing broiler chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 real time RT-PCR analysis with custom-designed primers and probes. Studies of the gene expression of cytokines and associated genes in chick...

  19. 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.

  20. Adipose tissue development in extramuscular and intramuscular depots in meat animals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cellular and metabolic aspects of developing intramuscular adipose tissue and other adipose tissue depots have been studied including examination of the expression of a number of genes. Depot dependent or depot “marker” genes such as stearoyl-CoA desaturase and leptin for subcutaneous adipose ti...

  1. 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

  2. Dietary sardine protein lowers insulin resistance, leptin and TNF-α and beneficially affects adipose tissue oxidative stress in rats with fructose-induced metabolic syndrome.

    PubMed

    Madani, Zohra; Louchami, Karim; Sener, Abdullah; Malaisse, Willy J; Ait Yahia, Dalila

    2012-02-01

    The present study aims at exploring the effects of sardine protein on insulin resistance, plasma lipid profile, as well as oxidative and inflammatory status in rats with fructose-induced metabolic syndrome. Rats were fed sardine protein (S) or casein (C) diets supplemented or not with high-fructose (HF) for 2 months. Rats fed the HF diets had greater body weight and adiposity and lower food intake as compared to control rats. Increased plasma glucose, insulin, HbA1C, triacylglycerols, free fatty acids and impaired glucose tolerance and insulin resistance was observed in HF-fed rats. Moreover, a decline in adipose tissues antioxidant status and a rise in lipid peroxidation and plasma TNF-α and fibrinogen were noted. Rats fed sardine protein diets exhibited lower food intake and fat mass than those fed casein diets. Sardine protein diets diminished plasma insulin and insulin resistance. Plasma triacylglycerol and free fatty acids were also lower, while those of α-tocopherol, taurine and calcium were enhanced as compared to casein diets. Moreover, S-HF diet significantly decreased plasma glucose and HbA1C. Sardine protein consumption lowered hydroperoxide levels in perirenal and brown adipose tissues. The S-HF diet, as compared to C-HF diet decreased epididymal hydroperoxides. Feeding sardine protein diets decreased brown adipose tissue carbonyls and increased glutathione peroxidase activity. Perirenal and epididymal superoxide dismutase and catalase activities and brown catalase activity were significantly greater in S-HF group than in C-HF group. Sardine protein diets also prevented hyperleptinemia and reduced inflammatory status in comparison with rats fed casein diets. Taken together, these results support the beneficial effect of sardine protein in fructose-induced metabolic syndrome on such variables as hyperglycemia, insulin resistance, hyperlipidemia and oxidative and inflammatory status, suggesting the possible use of sardine protein as a protective

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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

  12. The role of adiposity in the relationship between serum leptin and severe major depressive episode.

    PubMed

    Ubani, Chinedu C; Zhang, Jian

    2015-08-30

    To assess the role that adiposity plays in the association between leptin and major depressive episode (MDE), we analyzed the data of 1046 men and 1359 women aged 20-39 years, who completed an interview and had blood collected as a part of the National Health and Nutrition Examination Survey (NHANES) between 1991 and 1994. Waist-hip ratio (WHR) was used as an indicator of adiposity. MDE was assessed with the Diagnostic Interview Schedule. For normal-WHR women, the prevalence of MDE was reversely associated with leptin levels, 13.7(4.4)%, 12.2(4.0)% and 2.3(1.8)% respectively for lower, interquartile, and upper quartile. For abnormal-WHR women, the prevalence of MDE was positively associated with leptin, 6.1(2.3)%, 9.1(2.4)% and 20.0 (3.8) respectively for the three leptin levels. Compared to women with lower quartile of leptin, the odds ratio of MDE for women with upper quartile was 0.09 (0.01-0.98) for normal-WHR women but 4.35 (1.55-12.2) for abnormal-WHR women. No moderating effects were observed among men. Using BMI in place of WHR revealed similar findings. The association between MDE and leptin is moderated by adiposity. High leptin levels are associated with low odds of MDE among women with normal adiposity but high odds among women with abnormal adiposity. PMID:26032460

  13. Adipose tissue chromium and vanadium disbalance in high-fat fed Wistar rats.

    PubMed

    Tinkov, Alexey A; Popova, Elizaveta V; Polyakova, Valentina S; Kwan, Olga V; Skalny, Anatoly V; Nikonorov, Alexandr A

    2015-01-01

    The primary objective of the current study is to investigate the relationship between adipose tissue chromium and vanadium content and adipose tissue dysfunction in a model of diet-induced obesity. A total of 26 female Wistar rats were fed either standard or high-fat diet (31.6% of fat from total caloric content) for 3 months. High-fat-feeding resulted in 21 and 33% decrease in adipose tissue chromium and vanadium content, respectively. No change was seen in hair chromium or vanadium levels. Statistical analysis revealed a significant inverse correlation of adipose tissue Cr and V with animal morphometric parameters and adipocyte size. Significant inverse dependence was observed between adipose tissue Cr and V and serum leptin and proinflammatory cytokines' levels. At the same time, adipose tissue Cr and V levels were characterized by positive correlation between serum adiponectin and adiponectin/leptin ratio. Adipose tissue Cr and V were inversely correlated (p<0.05) with insulin and homeostatic model assessment insulin resistance index (HOMA-IR) levels. Cr and V concentrations were not correlated with serum glucose in either high-fat fed or control rats; however, both serum glucose and HOMA-IR levels were significantly higher in high-fat fed, compared to control, rats. The results allow to hypothesize that impairment of adipose tissue Cr and V content plays a certain role in the development of adipose tissue endocrine dysfunction in obesity. PMID:25194956

  14. 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

  15. Hypothalamic Leptin Gene Therapy Reduces Bone Marrow Adiposity in ob/ob Mice Fed Regular and High-Fat Diets.

    PubMed

    Lindenmaier, Laurence B; Philbrick, Kenneth A; Branscum, Adam J; Kalra, Satya P; Turner, Russell T; Iwaniec, Urszula T

    2016-01-01

    Low bone mass is often associated with elevated bone marrow adiposity. Since osteoblasts and adipocytes are derived from the same mesenchymal stem cell (MSC) progenitor, adipocyte formation may increase at the expense of osteoblast formation. Leptin is an adipocyte-derived hormone known to regulate energy and bone metabolism. Leptin deficiency and high-fat diet-induced obesity are associated with increased marrow adipose tissue (MAT) and reduced bone formation. Short-duration studies suggest that leptin treatment reduces MAT and increases bone formation in leptin-deficient ob/ob mice fed a regular diet. Here, we determined the long-duration impact of increased hypothalamic leptin on marrow adipocytes and osteoblasts in ob/ob mice following recombinant adeno-associated virus (rAAV) gene therapy. Eight- to 10-week-old male ob/ob mice were randomized into four groups: (1) untreated, (2) rAAV-Lep, (3) rAAV-green fluorescent protein (rAAV-GFP), or (4) pair-fed to rAAV-Lep. For vector administration, mice were injected intracerebroventricularly with either rAAV-leptin gene therapy (rAAV-Lep) or rAAV-GFP (9 × 10(7) particles) and maintained for 30 weeks. In a second study, the impact of increased hypothalamic leptin levels on MAT was determined in mice fed high-fat diets; ob/ob mice were randomized into two groups and treated with either rAAV-Lep or rAAV-GFP. At 7 weeks post-vector administration, half the mice in each group were switched to a high-fat diet for 8 weeks. Wild-type (WT) controls included age-matched mice fed regular or high-fat diet. High-fat diet resulted in a threefold increase in MAT in WT mice, whereas MAT was increased by leptin deficiency up to 50-fold. Hypothalamic leptin gene therapy increased osteoblast perimeter and osteoclast perimeter with minor change in cancellous bone architecture. The gene therapy decreased MAT levels in ob/ob mice fed regular or high-fat diet to values similar to WT mice fed regular diet. These findings suggest

  16. Hypothalamic Leptin Gene Therapy Reduces Bone Marrow Adiposity in ob/ob Mice Fed Regular and High-Fat Diets

    PubMed Central

    Lindenmaier, Laurence B.; Philbrick, Kenneth A.; Branscum, Adam J.; Kalra, Satya P.; Turner, Russell T.; Iwaniec, Urszula T.

    2016-01-01

    Low bone mass is often associated with elevated bone marrow adiposity. Since osteoblasts and adipocytes are derived from the same mesenchymal stem cell (MSC) progenitor, adipocyte formation may increase at the expense of osteoblast formation. Leptin is an adipocyte-derived hormone known to regulate energy and bone metabolism. Leptin deficiency and high-fat diet-induced obesity are associated with increased marrow adipose tissue (MAT) and reduced bone formation. Short-duration studies suggest that leptin treatment reduces MAT and increases bone formation in leptin-deficient ob/ob mice fed a regular diet. Here, we determined the long-duration impact of increased hypothalamic leptin on marrow adipocytes and osteoblasts in ob/ob mice following recombinant adeno-associated virus (rAAV) gene therapy. Eight- to 10-week-old male ob/ob mice were randomized into four groups: (1) untreated, (2) rAAV-Lep, (3) rAAV-green fluorescent protein (rAAV-GFP), or (4) pair-fed to rAAV-Lep. For vector administration, mice were injected intracerebroventricularly with either rAAV-leptin gene therapy (rAAV-Lep) or rAAV-GFP (9 × 107 particles) and maintained for 30 weeks. In a second study, the impact of increased hypothalamic leptin levels on MAT was determined in mice fed high-fat diets; ob/ob mice were randomized into two groups and treated with either rAAV-Lep or rAAV-GFP. At 7 weeks post-vector administration, half the mice in each group were switched to a high-fat diet for 8 weeks. Wild-type (WT) controls included age-matched mice fed regular or high-fat diet. High-fat diet resulted in a threefold increase in MAT in WT mice, whereas MAT was increased by leptin deficiency up to 50-fold. Hypothalamic leptin gene therapy increased osteoblast perimeter and osteoclast perimeter with minor change in cancellous bone architecture. The gene therapy decreased MAT levels in ob/ob mice fed regular or high-fat diet to values similar to WT mice fed regular diet. These findings suggest

  17. 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

  18. 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

  19. Sleep deprivation affects inflammatory marker expression in adipose tissue

    PubMed Central

    2010-01-01

    Sleep deprivation has been shown to increase inflammatory markers in rat sera and peripheral blood mononuclear cells. Inflammation is a condition associated with pathologies such as obesity, cancer, and cardiovascular diseases. We investigated changes in the pro and anti-inflammatory cytokines and adipokines in different depots of white adipose tissue in rats. We also assessed lipid profiles and serum levels of corticosterone, leptin, and adiponectin after 96 hours of sleep deprivation. Methods The study consisted of two groups: a control (C) group and a paradoxical sleep deprivation by 96 h (PSD) group. Ten rats were randomly assigned to either the control group (C) or the PSD. Mesenteric (MEAT) and retroperitoneal (RPAT) adipose tissue, liver and serum were collected following completion of the PSD protocol. Levels of interleukin (IL)-6, interleukin (IL)-10 and tumour necrosis factor (TNF)-α were analysed in MEAT and RPAT, and leptin, adiponectin, glucose, corticosterone and lipid profile levels were analysed in serum. Results IL-6 levels were elevated in RPAT but remained unchanged in MEAT after PSD. IL-10 protein concentration was not altered in either depot, and TNF-α levels decreased in MEAT. Glucose, triglycerides (TG), VLDL and leptin decreased in serum after 96 hours of PSD; adiponectin was not altered and corticosterone was increased. Conclusion PSD decreased fat mass and may modulate the cytokine content in different depots of adipose tissue. The inflammatory response was diminished in both depots of adipose tissue, with increased IL-6 levels in RPAT and decreased TNF-α protein concentrations in MEAT and increased levels of corticosterone in serum. PMID:21034496

  20. 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

  1. Postprandial Responses to Lipid and Carbohydrate Ingestion in Repeated Subcutaneous Adipose Tissue Biopsies in Healthy Adults.

    PubMed

    Dordevic, Aimee L; Pendergast, Felicity J; Morgan, Han; Villas-Boas, Silas; Caldow, Marissa K; Larsen, Amy E; Sinclair, Andrew J; Cameron-Smith, David

    2015-07-01

    Adipose tissue is a primary site of meta-inflammation. Diet composition influences adipose tissue metabolism and a single meal can drive an inflammatory response in postprandial period. This study aimed to examine the effect lipid and carbohydrate ingestion compared with a non-caloric placebo on adipose tissue response. Thirty-three healthy adults (age 24.5 ± 3.3 year (mean ± standard deviation (SD)); body mass index (BMI) 24.1 ± 3.2 kg/m2, were randomised into one of three parallel beverage groups; placebo (water), carbohydrate (maltodextrin) or lipid (dairy-cream). Subcutaneous, abdominal adipose tissue biopsies and serum samples were collected prior to (0 h), as well as 2 h and 4 h after consumption of the beverage. Adipose tissue gene expression levels of monocyte chemoattractant protein-1 (MCP-1), interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) increased in all three groups, without an increase in circulating TNF-α. Serum leptin (0.6-fold, p = 0.03) and adipose tissue leptin gene expression levels (0.6-fold, p = 0.001) decreased in the hours following the placebo beverage, but not the nutrient beverages. Despite increased inflammatory cytokine gene expression in adipose tissue with all beverages, suggesting a confounding effect of the repeated biopsy method, differences in metabolic responses of adipose tissue and circulating adipokines to ingestion of lipid and carbohydrate beverages were observed. PMID:26140541

  2. Postprandial Responses to Lipid and Carbohydrate Ingestion in Repeated Subcutaneous Adipose Tissue Biopsies in Healthy Adults

    PubMed Central

    Dordevic, Aimee L.; Pendergast, Felicity J.; Morgan, Han; Villas-Boas, Silas; Caldow, Marissa K.; Larsen, Amy E.; Sinclair, Andrew J.; Cameron-Smith, David

    2015-01-01

    Adipose tissue is a primary site of meta-inflammation. Diet composition influences adipose tissue metabolism and a single meal can drive an inflammatory response in postprandial period. This study aimed to examine the effect lipid and carbohydrate ingestion compared with a non-caloric placebo on adipose tissue response. Thirty-three healthy adults (age 24.5 ± 3.3 year (mean ± standard deviation (SD)); body mass index (BMI) 24.1 ± 3.2 kg/m2, were randomised into one of three parallel beverage groups; placebo (water), carbohydrate (maltodextrin) or lipid (dairy-cream). Subcutaneous, abdominal adipose tissue biopsies and serum samples were collected prior to (0 h), as well as 2 h and 4 h after consumption of the beverage. Adipose tissue gene expression levels of monocyte chemoattractant protein-1 (MCP-1), interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) increased in all three groups, without an increase in circulating TNF-α. Serum leptin (0.6-fold, p = 0.03) and adipose tissue leptin gene expression levels (0.6-fold, p = 0.001) decreased in the hours following the placebo beverage, but not the nutrient beverages. Despite increased inflammatory cytokine gene expression in adipose tissue with all beverages, suggesting a confounding effect of the repeated biopsy method, differences in metabolic responses of adipose tissue and circulating adipokines to ingestion of lipid and carbohydrate beverages were observed. PMID:26140541

  3. 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

  4. 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

  5. High-fructose diet leads to visceral adiposity and hypothalamic leptin resistance in male rats--do glucocorticoids play a role?

    PubMed

    Bursać, Biljana N; Vasiljević, Ana D; Nestorović, Nataša M; Veličković, Nataša A; Vojnović Milutinović, Danijela D; Matić, Gordana M; Djordjevic, Ana D

    2014-04-01

    Fructose overconsumption has been involved in the genesis and progression of the metabolic syndrome. Hypothalamus and adipose tissue, major organs for control of food intake and energy metabolism, play crucial roles in metabolic homeostasis. We hypothesized that glucocorticoid signaling mediates the effects of a fructose-enriched diet on visceral adiposity by acting on neuropeptide Y (NPY) in the hypothalamus and altering adipogenic transcription factors in the visceral adipose tissue. We analyzed the effects of 9-week consumption of 60% fructose solution on dyslipidemia, insulin and leptin sensitivity, and adipose tissue histology in male Wistar rats. Glucocorticoid signaling was assessed in both hypothalamus and visceral adipose tissue, while the levels of peroxisome-proliferator-activated receptor γ (PPARγ), sterol regulatory element-binding protein-1 (SREBP-1) and lipin-1, together with the levels of their target genes expression, were analyzed in the visceral adipose tissue. The results showed that long-term consumption of highly concentrated liquid fructose led to the development of visceral adiposity, elevated triglycerides and hypothalamic leptin resistance accompanied by stimulated glucocorticoid signaling and NPY mRNA elevation. Results from adipose tissue implied that fructose consumption shifted the balance between glucocorticoid receptor and adipogenic transcriptional factors (PPARγ, SREBP-1 and lipin-1) in favor of adipogenesis judged by distinctly separated populations of small adipocytes observed in this tissue. In summary, we propose that high-fructose-diet-induced alterations of glucocorticoid signaling in both hypothalamus and adipose tissue result in enhanced adipogenesis, possibly serving as an adaptation to energy excess in order to limit deposition of fat in nonadipose tissues. PMID:24565674

  6. 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

  7. 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

  8. 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

  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. Distinct Effects of Leptin and a Melanocortin Receptor Agonist Injected Into Medial Hypothalamic Nuclei on Glucose Uptake in Peripheral Tissues

    PubMed Central

    Toda, Chitoku; Shiuchi, Tetsuya; Lee, Suni; Yamato-Esaki, Maya; Fujino, Yusuke; Suzuki, Atsushi; Okamoto, Shiki; Minokoshi, Yasuhiko

    2009-01-01

    OBJECTIVE The medial hypothalamus mediates leptin-induced glucose uptake in peripheral tissues, and brain melanocortin receptors (MCRs) mediate certain central effects of leptin. However, the contributions of the leptin receptor and MCRs in individual medial hypothalamic nuclei to regulation of peripheral glucose uptake have remained unclear. We examined the effects of an injection of leptin and the MCR agonist MT-II into medial hypothalamic nuclei on glucose uptake in peripheral tissues. RESEARCH DESIGN AND METHODS Leptin or MT-II was injected into the ventromedial (VMH), dorsomedial (DMH), arcuate nucleus (ARC), or paraventricular (PVH) hypothalamus or the lateral ventricle (intracerebroventricularly) in freely moving mice. The MCR antagonist SHU9119 was injected intracerebroventricularly. Glucose uptake was measured by the 2-[3H]deoxy-d-glucose method. RESULTS Leptin injection into the VMH increased glucose uptake in skeletal muscle, brown adipose tissue (BAT), and heart, whereas that into the ARC increased glucose uptake in BAT, and that into the DMH or PVH had no effect. SHU9119 abolished these effects of leptin injected into the VMH. Injection of MT-II either into the VMH or intracerebroventricularly increased glucose uptake in skeletal muscle, BAT, and heart, whereas that into the PVH increased glucose uptake in BAT, and that into the DMH or ARC had no effect. CONCLUSIONS The VMH mediates leptin- and MT-II–induced glucose uptake in skeletal muscle, BAT, and heart. These effects of leptin are dependent on MCR activation. The leptin receptor in the ARC and MCR in the PVH regulate glucose uptake in BAT. Medial hypothalamic nuclei thus play distinct roles in leptin- and MT-II–induced glucose uptake in peripheral tissues. PMID:19752162

  11. 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

  12. 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

  13. [Relationships of hormones of adipose tissue and ghrelin to bone metabolism].

    PubMed

    Zofková, I

    2009-06-01

    Body adipose tissue influences bone metabolism through mechanical load, as well as via hormones released into circulation. Such hormones are adipocytokines--leptin, adiponectin, TNF-alpha, IL-6, resistin and visfatin. Some of them exert an osteoanabolic effect, while the others activate bone resorption. An increasingly discussed adipocytokine is leptin, which fundamental role is regulation of food intake ensuring survival of the organism during starvation. Leptin also stimulates osteoblasts and activates bone formation. The direct osteotropic effect of leptin is modulated by interaction with hypothalamic centers and neurohormones. Apparently, the most important leptin sensitive pathway involved in bone regulation is the beta-adrenergic system. While activation of beta-1-adrenergic receptors by leptin enhances bone formation, activation of beta-2-adrenergic receptors in hypothalamus and in the skeleton increases bone resorption. In humans, an anabolic effect on the skeleton prevails. In pubertal girls, leptin extensively released into circulation at the moment when adipose tissue reaches a critical volume, stimulates synthesis of GnRH and induces puberty, which is followed by striking increases in bone mass. Low leptin levels in anorexia nervosa are associated with amenorrhoea, which slows down increase of bone mass and may induce osteopenia. Important adipocytokine with an unambiguous negative effect on bone is adiponectin. Decreased production of this hormone explains in part the lower prevalence of osteoporosis in obese persons. In this article, the osteotropic importance ofleptin-sensitive neurohormonal mechanisms and other hormones related to adipose tissue are discussed. Clinical importance of the above mentioned hormones to integrity of the skeleton has not yet been verified. PMID:19662887

  14. Molecular Characterization of Adipose Tissue in the African Elephant (Loxodonta africana)

    PubMed Central

    Choong, Siew S.; Giles, Thomas C.; Sells, James; May, Sean; Stansfield, Fiona J.; Allen, William R.; Emes, Richard D.; Mostyn, Alison; Mongan, Nigel P.; Yon, Lisa

    2014-01-01

    Adipose tissue (AT) is a dynamic and flexible organ with regulatory roles in physiological functions including metabolism, reproduction and inflammation; secreted adipokines, including leptin, and fatty acids facilitate many of these roles. The African elephant (Loxodonta africana) is experiencing serious challenges to optimal reproduction in captivity. The physiological and molecular basis of this impaired fertility remains unknown. AT production of leptin is a crucial molecular link between nutritional status, adiposity and fertility in many species. We propose that leptin has a similar function in the African elephant. African elephant visceral and subcutaneous adipose tissue (AT) was obtained from both sexes and a range of ages including females with known pregnancy status. RNA was extracted and histological sections created and analyzed by microarray, PCR and immunohistochemistry respectively. Gas-chromatography was used to determine the fatty acid composition of AT. Microarray expression profiling was used to compare gene expression profiles of AT from pre-pubertal versus reproductively competent adult African elephants. This study demonstrates, for the first time, leptin mRNA and protein expression in African elephant AT. The derived protein sequence of the elephant leptin protein was exploited to determine its relationship within the class I helical cytokine superfamily, which indicates that elephant leptin is most closely related to the leptin orthologs of Oryctolagus cuniculus (European rabbit), Lepus oiostolus (woolly hare), and members of the Ochotonidae (Pika). Immunohistological analysis identified considerable leptin staining within the cytoplasm of adipocytes. Significant differences in fatty acid profiles between pregnant and non-pregnant animals were revealed, most notably a reduction in both linoleic and α linoleic acid in pregnant animals. This report forms the basis for future studies to address the effect of nutrient composition and body

  15. Molecular characterization of adipose tissue in the African elephant (Loxodonta africana).

    PubMed

    Nilsson, Emeli M; Fainberg, Hernan P; Choong, Siew S; Giles, Thomas C; Sells, James; May, Sean; Stansfield, Fiona J; Allen, William R; Emes, Richard D; Mostyn, Alison; Mongan, Nigel P; Yon, Lisa

    2014-01-01

    Adipose tissue (AT) is a dynamic and flexible organ with regulatory roles in physiological functions including metabolism, reproduction and inflammation; secreted adipokines, including leptin, and fatty acids facilitate many of these roles. The African elephant (Loxodonta africana) is experiencing serious challenges to optimal reproduction in captivity. The physiological and molecular basis of this impaired fertility remains unknown. AT production of leptin is a crucial molecular link between nutritional status, adiposity and fertility in many species. We propose that leptin has a similar function in the African elephant. African elephant visceral and subcutaneous adipose tissue (AT) was obtained from both sexes and a range of ages including females with known pregnancy status. RNA was extracted and histological sections created and analyzed by microarray, PCR and immunohistochemistry respectively. Gas-chromatography was used to determine the fatty acid composition of AT. Microarray expression profiling was used to compare gene expression profiles of AT from pre-pubertal versus reproductively competent adult African elephants. This study demonstrates, for the first time, leptin mRNA and protein expression in African elephant AT. The derived protein sequence of the elephant leptin protein was exploited to determine its relationship within the class I helical cytokine superfamily, which indicates that elephant leptin is most closely related to the leptin orthologs of Oryctolagus cuniculus (European rabbit), Lepus oiostolus (woolly hare), and members of the Ochotonidae (Pika). Immunohistological analysis identified considerable leptin staining within the cytoplasm of adipocytes. Significant differences in fatty acid profiles between pregnant and non-pregnant animals were revealed, most notably a reduction in both linoleic and α linoleic acid in pregnant animals. This report forms the basis for future studies to address the effect of nutrient composition and body

  16. Proopiomelanocortin, agouti-related protein, and leptin in human cerebrospinal fluid: correlations with body weight and adiposity.

    PubMed

    Page-Wilson, Gabrielle; Meece, Kana; White, Anne; Rosenbaum, Michael; Leibel, Rudolph L; Smiley, Richard; Wardlaw, Sharon L

    2015-09-01

    Leptin and its neuronal targets, which produce proopiomelanocortin (POMC) and agouti-related protein (AgRP), regulate energy balance. This study characterized leptin, POMC, and AgRP in the cerebrospinal fluid (CSF) of 47 healthy human subjects, 23 lean and 24 overweight/obese (OW/OB), as related to BMI, adiposity, plasma leptin, soluble leptin receptor (s-OB-R), and insulin. POMC was measured since the POMC prohormone is the predominant POMC peptide in CSF and correlates with hypothalamic POMC in rodents. Plasma AgRP was similarly characterized. CSF leptin was 83-fold lower than in plasma and correlated strongly with BMI, body fat, and insulin. The relative amount of leptin transported into CSF declined with increasing BMI, ranging from 4.5 to 0.52%, consistent with a saturable transport mechanism. CSF sOB-R was 78-fold lower than in plasma and correlated negatively with plasma and CSF leptin. CSF POMC was higher in lean vs. OW/OB subjects (P < 0.001) and correlated negatively with CSF leptin (r = -0.60, P < 0.001) and with plasma leptin, insulin, BMI, and adiposity. CSF AgRP was not different in lean vs. OW/OB; however, plasma AgRP was higher in lean subjects (P = 0.001) and correlated negatively with BMI, adiposity, leptin, insulin, and HOMA (P < 0.005). Thus, CSF measurements may provide useful biomarkers for brain leptin and POMC activity. The striking negative correlation between CSF leptin and POMC could be secondary to leptin resistance and/or neuronal changes associated with obesity but may also indicate that POMC plays a primary role in regulating body weight and adiposity. The role of plasma AgRP as a neuroendocrine biomarker deserves further study. PMID:26152765

  17. The role of GH in adipose tissue: lessons from adipose-specific GH receptor gene-disrupted mice.

    PubMed

    List, Edward O; Berryman, Darlene E; Funk, Kevin; Gosney, Elahu S; Jara, Adam; Kelder, Bruce; Wang, Xinyue; Kutz, Laura; Troike, Katie; Lozier, Nicholas; Mikula, Vincent; Lubbers, Ellen R; Zhang, Han; Vesel, Clare; Junnila, Riia K; Frank, Stuart J; Masternak, Michal M; Bartke, Andrzej; Kopchick, John J

    2013-03-01

    GH receptor (GHR) gene-disrupted mice (GHR-/-) have provided countless discoveries as to the numerous actions of GH. Many of these discoveries highlight the importance of GH in adipose tissue. For example GHR-/- mice are insulin sensitive yet obese with preferential enlargement of the sc adipose depot. GHR-/- mice also have elevated levels of leptin, resistin, and adiponectin, compared with controls leading some to suggest that GH may negatively regulate certain adipokines. To help clarify the role that GH exerts specifically on adipose tissue in vivo, we selectively disrupted GHR in adipose tissue to produce Fat GHR Knockout (FaGHRKO) mice. Surprisingly, FaGHRKOs shared only a few characteristics with global GHR-/- mice. Like the GHR-/- mice, FaGHRKO mice are obese with increased total body fat and increased adipocyte size. However, FaGHRKO mice have increases in all adipose depots with no improvements in measures of glucose homeostasis. Furthermore, resistin and adiponectin levels in FaGHRKO mice are similar to controls (or slightly decreased) unlike the increased levels found in GHR-/- mice, suggesting that GH does not regulate these adipokines directly in adipose tissue in vivo. Other features of FaGHRKO mice include decreased levels of adipsin, a near-normal GH/IGF-1 axis, and minimal changes to a large assortment of circulating factors that were measured such as IGF-binding proteins. In conclusion, specific removal of GHR in adipose tissue is sufficient to increase adipose tissue and decrease circulating adipsin. However, removal of GHR in adipose tissue alone is not sufficient to increase levels of resistin or adiponectin and does not alter glucose metabolism. PMID:23349524

  18. Oncogenic role of leptin and Notch interleukin-1 leptin crosstalk outcome in cancer

    PubMed Central

    Lipsey, Crystal C; Harbuzariu, Adriana; Daley-Brown, Danielle; Gonzalez-Perez, Ruben R

    2016-01-01

    Obesity is a global pandemic characterized by high levels of body fat (adiposity) and derived-cytokines (i.e., leptin). Research shows that adiposity and leptin provide insight on the link between obesity and cancer progression. Leptin’s main function is to regulate energy balance. However, obese individuals routinely develop leptin resistance, which is the consequence of the breakdown in the signaling mechanism controlling satiety resulting in the accumulation of leptin. Therefore, leptin levels are often chronically elevated in human obesity. Elevated leptin levels are related to higher incidence, increased progression and poor prognosis of several human cancers. In addition to adipose tissue, cancer cells can also secrete leptin and overexpress leptin receptors. Leptin is known to act as a mitogen, inflammatory and pro-angiogenic factor that induces cancer cell proliferation and tumor angiogenesis. Moreover, leptin signaling induces cancer stem cells, which are involved in cancer recurrence and drug resistance. A novel and complex signaling crosstalk between leptin, Notch and interleukin-1 (IL-1) [Notch, IL-1 and leptin crosstalk outcome (NILCO)] seems to be an important driver of leptin-induced oncogenic actions. Leptin and NILCO signaling mediate the activation of cancer stem cells that can affect drug resistance. Thus, leptin and NILCO signaling are key links between obesity and cancer progression. This review presents updated data suggesting that adiposity affects cancer incidence, progression, and response to treatment. Here we show data supporting the oncogenic role of leptin in breast, endometrial, and pancreatic cancers. PMID:27019796

  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. Leptin-independent programming of adult body weight and adiposity in mice.

    PubMed

    Cottrell, Elizabeth C; Martin-Gronert, Malgorzata S; Fernandez-Twinn, Denise S; Luan, Jian'an; Berends, Lindsey M; Ozanne, Susan E

    2011-02-01

    Low birth weight and rapid postnatal weight gain are independent and additive risk factors for the subsequent development of metabolic disease. Despite an abundance of evidence for these associations, mechanistic data are lacking. The hormone leptin has received significant interest as a potential programming factor, because differences in the profile of leptin in early life have been associated with altered susceptibility to obesity. Whether leptin alone is a critical factor for programming obesity has, until now, remained unclear. Using the leptin-deficient ob/ob mouse, we show that low birth weight followed by rapid catch-up growth during lactation (recuperated offspring) leads to a persistent increase in body weight in adult life, both in wild-type and ob/ob animals. Furthermore, recuperated offspring are hyperphagic and epididymal fat pad weights are significantly increased, reflecting greater adiposity. These results show definitively that factors other than leptin are crucial in the programming of energy homeostasis in this model and are powerful enough to alter adiposity in a genetically obese strain. PMID:21209019

  1. Physiology of leptin: energy homeostasis, neuroendocrine function and metabolism

    PubMed Central

    Park, Hyeong-Kyu; Ahima, Rexford S.

    2014-01-01

    Leptin is secreted by adipose tissue and regulates energy homeostasis, neuroendocrine function, metabolism, immune function and other systems through its effects on the central nervous system and peripheral tissues. Leptin administration has been shown to restore metabolic and neuroendocrine abnormalities in individuals with leptin-deficient states, including hypothalamic amenorrhea and lipoatrophy. In contrast, obese individuals are resistant to leptin. Recombinant leptin is beneficial in patients with congenital leptin deficiency or generalized lipodystrophy. However, further research on molecular mediators of leptin resistance is needed for the development of targeted leptin sensitizing therapies for obesity and related metabolic diseases. PMID:25199978

  2. 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

  3. 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

  4. Adipose atrophy in cancer cachexia: morphologic and molecular analysis of adipose tissue in tumour-bearing mice.

    PubMed

    Bing, C; Russell, S; Becket, E; Pope, M; Tisdale, M J; Trayhurn, P; Jenkins, J R

    2006-10-23

    Extensive loss of adipose tissue is a hallmark of cancer cachexia but the cellular and molecular basis remains unclear. This study has examined morphologic and molecular characteristics of white adipose tissue in mice bearing a cachexia-inducing tumour, MAC16. Adipose tissue from tumour-bearing mice contained shrunken adipocytes that were heterogeneous in size. Increased fibrosis was evident by strong collagen-fibril staining in the tissue matrix. Ultrastructure of 'slimmed' adipocytes revealed severe delipidation and modifications in cell membrane conformation. There were major reductions in mRNA levels of adipogenic transcription factors including CCAAT/enhancer binding protein alpha (C/EBPalpha), CCAAT/enhancer binding protein beta, peroxisome proliferator-activated receptor gamma, and sterol regulatory element binding protein-1c (SREBP-1c) in adipose tissue, which was accompanied by reduced protein content of C/EBPalpha and SREBP-1. mRNA levels of SREBP-1c targets, fatty acid synthase, acetyl CoA carboxylase, stearoyl CoA desaturase 1 and glycerol-3-phosphate acyl transferase, also fell as did glucose transporter-4 and leptin. In contrast, mRNA levels of peroxisome proliferators-activated receptor gamma coactivator-1alpha and uncoupling protein-2 were increased in white fat of tumour-bearing mice. These results suggest that the tumour-induced impairment in the formation and lipid storing capacity of adipose tissue occurs in mice with cancer cachexia. PMID:17047651

  5. The expression of ob gene is not acutely regulated by insulin and fasting in human abdominal subcutaneous adipose tissue.

    PubMed

    Vidal, H; Auboeuf, D; De Vos, P; Staels, B; Riou, J P; Auwerx, J; Laville, M

    1996-07-15

    The regulation of ob gene expression in abdominal subcutaneous adipose tissue was investigated using a reverse transcription-competitive PCR method to quantify the mRNA level of leptin. Leptin mRNA level was highly correlated with the body mass index of 26 subjects (12 lean, 7 non-insulin-dependent diabetic, and 7 obese patients). The effect of fasting on ob gene expression was investigated in 10 subjects maintained on a hypocaloric diet (1045 KJ/d) for 5 d. While their metabolic parameters significantly changed (decrease in insulinemia, glycemia, and resting metabolic rate and increase in plasma ketone bodies), the caloric restriction did not modify the leptin mRNA level in the adipose tissue. To verify whether insulin regulates ob gene expression, six lean subjects underwent a 3-h euglycemic hyperinsulinemic (846 +/- 138 pmol/liter) clamp. Leptin and Glut 4 mRNA levels were quantified in adipose tissue biopsies taken before and at the end of the clamp. Insulin infusion produced a significant threefold increase in Glut 4 mRNA while leptin mRNA was not affected. It is concluded that ob gene expression is not acutely regulated by insulin or by metabolic factors related to fasting in human abdominal subcutaneous adipose tissue. PMID:8755631

  6. 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

  7. 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

  8. Fasting insulin levels influence plasma leptin levels independently from the contribution of adiposity: evidence from both a cross-sectional and an intervention study.

    PubMed

    Doucet, E; St-Pierre, S; Alméras, N; Mauriège, P; Després, J P; Richard, D; Bouchard, C; Tremblay, A

    2000-11-01

    The aim of the present investigation was to determine whether leptinemia is only a reflection of the status of fat stores or if insulinemia has a significant influence over leptin levels. Study 1 focused on the association between fasting plasma insulin and leptin in subjects of the Quebec Family Study who were first classified as either high- or low-insulin individuals and were then individually matched on the basis of fat mass (FM). In Study 2, 19 men and 23 women took part in a 15-week weight loss program that consisted of drug therapy (fenfluramine, 60 mg/day) or placebo coupled to an energy-restricted diet (-2930 kJ/day). Body weight, FM, and fat-free mass (assessed by underwater weighing) as well as visceral and sc abdominal and mid-thigh adipose tissue measured by computed tomography were assessed before and after weight loss. Blood samples were drawn and analyzed for fasting plasma insulin and leptin before and after weight loss. In Study 1, significant positive associations were noted between log10 transformed fasting insulin and leptin in both men (r = 0.55, P < 0.0001) and women (r = 0.48, P < 0.0001). Moreover, after having carefully matched high-insulin to low-insulin individuals on the basis of FM, significantly lower leptin levels were observed in the low-insulin groups, in men (5.5 vs. 8.1 ng/mL, P < 0.05) as well as in women (18.7 vs. 24 ng/mL, P < 0.05). Results from Study 2 showed significant reductions of body weight, FM, fat-free mass, visceral abdominal tissue, sc abdominal tissue, and mid-thigh adipose tissue levels in men and women in response to the weight loss protocol. Moreover, the decrease in fasting plasma insulin was the only significant correlate of changes in fasting plasma leptin levels during weight loss, even after corrections for changes in FM in both men (r = 0.50, P < 0.05) and women (r = 0.46, P < 0.05). These results suggest that in a population characterized by a wide range of adiposity hyperinsulinemia has the potential to

  9. 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

  10. Differential Patterns of Serum Concentration and Adipose Tissue Expression of Chemerin in Obesity: Adipose Depot Specificity and Gender Dimorphism

    PubMed Central

    Alfadda, Assim A; Sallam, Reem M; Chishti, Muhammad Azhar; Moustafa, Amr S; Fatma, Sumbul; Alomaim, Waleed S; Al-Naami, Mohammed Y; Bassas, Abdulelah F; Chrousos, George P; Jo, Hyunsun

    2012-01-01

    Chemerin, a recognized chemoattractant, is expressed in adipose tissue and plays a role in adipocytes differentiation and metabolism. Gender- and adipose tissue-specific differences in human chemerin expression have not been well characterized. Therefore, these differences were assessed in the present study. The body mass index (BMI) and the circulating levels of chemerin and other inflammatory, adiposity and insulin resistance markers were assessed in female and male adults of varying degree of obesity. Chemerin mRNA expression was also measured in paired subcutaneous and visceral adipose tissue samples obtained from a subset of the study subjects. Serum chemerin concentrations correlated positively with BMI and serum leptin levels and negatively with high density lipoprotein (HDL)-cholesterol levels. No correlation was found between serum chemerin concentrations and fasting glucose, total cholesterol, low density lipoprotein (LDL)-cholesterol, triglycerides, insulin, C-reactive protein or adiponectin. Similarly, no relation was observed with the homeostasis model assessment for insulin resistance (HOMA-IR) values. Gender- and adipose tissue-specific differences were observed in chemerin mRNA expression levels, with expression significantly higher in women than men and in subcutaneous than visceral adipose tissue. Interestingly, we found a significant negative correlation between circulating chemerin levels and chemerin mRNA expression in subcutaneous fat. Among the subjects studied, circulating chemerin levels were associated with obesity markers but not with markers of insulin resistance. At the tissue level, fat depot-specific differential regulation of chemerin mRNA expression might contribute to the distinctive roles of subcutaneous vs. visceral adipose tissue in human obesity. PMID:22544171

  11. Cross-tissue comparisons of leptin and adiponectin

    PubMed Central

    Houde, Andrée-Anne; Légaré, Cécilia; Hould, Frédéric-Simon; Lebel, Stéfane; Marceau, Picard; Tchernof, André; Vohl, Marie-Claude; Hivert, Marie-France; Bouchard, Luigi

    2014-01-01

    DNA methylation has been mostly studied in circulating blood cells. Although being readily accessible, metabolically active tissues such as adipose tissue would be more informative for the study of metabolic disorders. However, whether or not the blood DNA methylation profile correlates with that of adipose tissue remains unknown. In this study, DNA methylation patterns of variation at LEP and ADIPOQ gene loci were similar between individual CpGs across the different tissues. We also report that DNA methylation levels at biologically relevant CpGs are correlated between blood, subcutaneous, and visceral adipose tissue, and that these nearby CpGs are associated with LEP and ADIPOQ gene expression in adipose tissues. These results will be highly relevant for future epigenetic studies in metabolic disorders. PMID:24719787

  12. 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

  13. 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

  14. 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

  15. Adipose tissue glycogen accumulation is associated with obesity-linked inflammation in humans

    PubMed Central

    Ceperuelo-Mallafré, Victòria; Ejarque, Miriam; Serena, Carolina; Duran, Xavier; Montori-Grau, Marta; Rodríguez, Miguel Angel; Yanes, Oscar; Núñez-Roa, Catalina; Roche, Kelly; Puthanveetil, Prasanth; Garrido-Sánchez, Lourdes; Saez, Enrique; Tinahones, Francisco J.; Garcia-Roves, Pablo M.; Gómez-Foix, Anna Ma; Saltiel, Alan R.; Vendrell, Joan; Fernández-Veledo, Sonia

    2015-01-01

    Objective Glycogen metabolism has emerged as a mediator in the control of energy homeostasis and studies in murine models reveal that adipose tissue might contain glycogen stores. Here we investigated the physio(patho)logical role of glycogen in human adipose tissue in the context of obesity and insulin resistance. Methods We studied glucose metabolic flux of hypoxic human adipoctyes by nuclear magnetic resonance and mass spectrometry-based metabolic approaches. Glycogen synthesis and glycogen content in response to hypoxia was analyzed in human adipocytes and macrophages. To explore the metabolic effects of enforced glycogen deposition in adipocytes and macrophages, we overexpressed PTG, the only glycogen-associated regulatory subunit (PP1-GTS) reported in murine adipocytes. Adipose tissue gene expression analysis was performed on wild type and homozygous PTG KO male mice. Finally, glycogen metabolism gene expression and glycogen accumulation was analyzed in adipose tissue, mature adipocytes and resident macrophages from lean and obese subjects with different degrees of insulin resistance in 2 independent cohorts. Results We show that hypoxia modulates glucose metabolic flux in human adipocytes and macrophages and promotes glycogenesis. Enforced glycogen deposition by overexpression of PTG re-orients adipocyte secretion to a pro-inflammatory response linked to insulin resistance and monocyte/lymphocyte migration. Furthermore, glycogen accumulation is associated with inhibition of mTORC1 signaling and increased basal autophagy flux, correlating with greater leptin release in glycogen-loaded adipocytes. PTG-KO mice have reduced expression of key inflammatory genes in adipose tissue and PTG overexpression in M0 macrophages induces a pro-inflammatory and glycolytic M1 phenotype. Increased glycogen synthase expression correlates with glycogen deposition in subcutaneous adipose tissue of obese patients. Glycogen content in subcutaneous mature adipocytes is associated

  16. Expression of inflammatory cytokines by adipose tissue from patients with endometrial cancer.

    PubMed

    Zemlyak, A; Zakhaleva, J; Pearl, M; Mileva, I; Gelato, M; Mynarcik, D; McNurlan, M

    2012-01-01

    Obesity results in increased mortality from many forms of cancer. We looked at the levels of gene expression for TNFalpha, IL-6, IkappaB kinase (inhibitor of NF-kappaB), CD 68 (glycoprotein expressed on macrophages) and leptin in samples of adipose tissue from individuals with endometrial cancer versus patients with benign conditions. This is a prospective study which included patients of a gynecologic oncology group. A piece of omental tissue was harvested from them during surgery. RNA was purified from all samples. Relative amounts of RNA for IkappaB, TNFalpha, IL-6, CD68 and leptin were calculated. Pearson's correlation method was used to correlate RNA levels with BMI. Logistic regression method was used to compare gene expression for cancer and control groups. The total sample size was 56 (24 endometrial cancer and 32 controls). IkappaB, TNFalpha and IL-6 levels increased linearly with increasing BMI in the control group. There was no correlation of IkappaB, TNFalpha, IL-6 or CD-68 levels with cancer status of the patients. Leptin had a weak protective effect against endometrial cancer (odds ratio = 0.92). Obesity is associated with increased expression of certain inflammatory cytokines in the adipose tissue. However, increased levels of these inflammatory markers in the adipose tissue of the omentum are not associated with presence of endometrial cancer. PMID:23091891

  17. Altered adipose tissue metabolism in offspring of dietary obese rat dams.

    PubMed

    Benkalfat, Nassira Batoul; Merzouk, Hafida; Bouanane, Samira; Merzouk, Sid-Ahmed; Bellenger, Jérôme; Gresti, Joseph; Tessier, Christian; Narce, Michel

    2011-07-01

    To investigate further the mechanisms of developmental programming, we analysed the effects of maternal overnutrition and of postnatal high-fat feeding on adipose tissue metabolism in the offspring. Postnatal changes in serum adiponectin, leptin and TAG [triacylglycerol (triglyceride)] levels, adipose tissue TAGs, fatty acids and enzyme activities were determined in offspring of cafeteria-diet-fed dams during gestation and lactation, weaned on to standard chow or on to cafeteria diet. Obese rats showed higher adiposity (+35% to 85%) as well as a significant increase in serum glucose, insulin, leptin, adiponectin and TAG levels (P<0.01) and adipose tissue LPL (lipoprotein lipase) and GPDH (glycerol-3-phosphate dehydrogenase) activities (P<0.01), compared with control pups at weaning (day 21) and at adulthood (day 90). Adipose HSL (hormone-sensitive lipase) activity was increased only at day 90 (P<0.05), and FAS (fatty acid synthase) activity remained unchanged. The proportions of SFAs (saturated fatty acids) and MUFAs (mono-unsaturated fatty acids) and the Δ(9)-desaturation index were significantly increased (P<0.05), whereas PUFAs (polyunsaturated fatty acids) were decreased (P<0.01) in serum and adipose TAGs of obese pups compared with controls. The cafeteria diet at weaning induced more severe abnormalities in obese rats. In conclusion, maternal overnutrition induced permanent changes in adipose tissue metabolism of the offspring. These pre-existing alterations in offspring were worsened under a high-fat diet from weaning to adulthood. Consequently, adipose adipokines and enzymes could provide a potential therapeutic target, and new investigations in this field could constitute strategies to improve the impact of early-life overnutrition. PMID:21288203

  18. 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

  19. 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

  20. 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

  1. Leptin and Hormones: Energy Homeostasis.

    PubMed

    Triantafyllou, Georgios A; Paschou, Stavroula A; Mantzoros, Christos S

    2016-09-01

    Leptin, a 167 amino acid adipokine, plays a major role in human energy homeostasis. Its actions are mediated through binding to leptin receptor and activating JAK-STAT3 signal transduction pathway. It is expressed mainly in adipocytes, and its circulating levels reflect the body's energy stores in adipose tissue. Recombinant methionyl human leptin has been FDA approved for patients with generalized non-HIV lipodystrophy and for compassionate use in subjects with congenital leptin deficiency. The purpose of this review is to outline the role of leptin in energy homeostasis, as well as its interaction with other hormones. PMID:27519135

  2. 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

  3. 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

  4. Effect of polymorphisms linked to LEP gene on its expression on adipose tissues in beef cattle.

    PubMed

    Passos, D T; Hepp, D; Moraes, J C F; Weimer, T A

    2007-06-01

    In cattle, genetic markers at the leptin (LEP) gene and at those linked to the gene have been described as affecting calving interval (markers LEPSau3AI and IDVGA51), or daily weight gain (BMS1074 and BM1500). This work investigated the effect of these alleles on LEP mRNA levels in cattle subcutaneous and omental adipose tissues. A sample of 137 females of a Brangus-Ibage beef cattle herd was analysed to evaluate the distribution of the polymorphisms; then, animals having at least one of the IDVGA51*181 (allele 181 at marker IDVGA51; six animals), LEPSau3AI*2 (four), BMS1074*151 (13), BM1500*135 (six) alleles and a control group composed of animals without any of these alleles (four animals) were submitted to surgery to obtain omental and subcutaneous adipose tissues. Leptin mRNA expression was quantified by TaqMan RT-PCR, using 18S rRNA as internal control and adjusted for the effect of body condition score, through regression analysis. Omental fat had LEP gene expression 33% lower than the subcutaneous tissue. Carriers of IDVGA*181 and BMS1074*151 showed subcutaneous fat leptin mRNA levels higher than the controls. Leptin controls feed intake and coordinates reproduction; therefore, animals with higher LEP gene expression will probably have lower daily weight gain than others with similar forage offer and nutritional condition and probably will also have longer calving interval. PMID:17550358

  5. 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...

  6. 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

  7. Adiponectin Isoforms and Leptin Impact on Rheumatoid Adipose Mesenchymal Stem Cells Function

    PubMed Central

    Skalska, Urszula; Kontny, Ewa

    2016-01-01

    Adiponectin and leptin have recently emerged as potential risk factors in rheumatoid arthritis (RA) pathogenesis. In this study we evaluated the effects of adiponectin and leptin on immunomodulatory function of adipose mesenchymal stem cells (ASCs) derived from infrapatellar fat pad of RA patients. ASCs were stimulated with leptin, low molecular weight (LMW) and high/middle molecular weight (HMW/MMW) adiponectin isoforms. The secretory activity of ASCs and their effect on rheumatoid synovial fibroblasts (RA-FLS) and peripheral blood mononuclear cells (PBMCs) from healthy donors have been analysed. RA-ASCs secreted spontaneously TGFβ, IL-6, IL-1Ra, PGE2, IL-8, and VEGF. Secretion of all these factors was considerably upregulated by HMW/MMW adiponectin, but not by LMW adiponectin and leptin. Stimulation with HMW/MMW adiponectin partially abolished proproliferative effect of ASC-derived soluble factors on RA-FLS but did not affect IL-6 secretion in FLS cultures. ASCs pretreated with HMW/MMW adiponectin maintained their anti-inflammatory function towards PBMCs, which was manifested by moderate PBMCs proliferation inhibition and IL-10 secretion induction. We have proved that HMW/MMW adiponectin stimulates secretory potential of rheumatoid ASCs but does not exert strong impact on ASCs function towards RA-FLS and PBMCs. PMID:26681953

  8. 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

  9. Adipose Tissue and Adipokines: The Association with and Application of Adipokines in Obesity

    PubMed Central

    Khan, Muhammad; Joseph, Frank

    2014-01-01

    2014 marks the 20th anniversary of adipokines. Through the identification of leptin, our perceived understanding of adipose tissue was changed instantaneously. From a simple dormant site of energy storage, adipose tissue is now recognized as an integral hub of various hormones known as adipokines. Although great strides have been made in characterizing these hormones in health, research also shows they are significantly implicated in a series of pathologies. One such condition is obesity. Defined as an excess of adipose tissue, obesity remains one of the greatest healthcare epidemics of the 21st century. With no definitive treatment, attention has shifted to understanding the role of adipokines in obesity. This review provides an introduction to the salient obesity-related adipokines and their possible application as a treatment for obesity. PMID:25309775

  10. 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

  11. [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

  12. 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

  13. Associations of Testosterone and Sex Hormone Binding Globulin with Adipose Tissue Hormones in Midlife Women

    PubMed Central

    Wildman, Rachel P.; Wang, Dan; Fernandez, Ivonne; Mancuso, Peter; Santoro, Nanette; Scherer, Philipp E.; Sowers, MaryFran R.

    2014-01-01

    Objective Regulators of adipose tissue hormones remain incompletely understood, but may include sex hormones. As adipose tissue hormones have been shown to contribute to numerous metabolic and cardiovascular disorders, understanding their regulation in midlife women is of clinical importance. Therefore, we assessed the associations between testosterone (T) and sex hormone binding globulin (SHBG) with leptin, high molecular weight (HMW) adiponectin, and the soluble form of the leptin receptor (sOB-R) in healthy midlife women. Design and Methods Cross-sectional analyses were performed using data from 1,881 midlife women (average age 52.6 (±2.7) years) attending the sixth Annual follow-up visit of the multiethnic Study of Women’s Health Across the Nation. Results T was weakly negatively associated with both HMW adiponectin and sOB-R (r = −0.12 and r = −0.10, respectively; P < 0.001 for both), and positively associated with leptin (r = 0.17; P < 0.001). SHBG was more strongly and positively associated with both HMW adiponectin and sOB-R (r = 0.29 and r = 0.24, respectively; P < 0.001 for both), and more strongly and negatively associated with leptin (r = −0.27; P < 0.001). Adjustment for fat mass, insulin resistance, or waist circumference only partially diminished associations with HMW adiponectin and sOB-R, but attenuated associations with leptin. In conclusion, in these midlife women, lower SHBG values, and to a lesser extent, higher T levels, were associated with lower, or less favorable, levels of adiponectin and sOB-R, independent of fat mass. Conclusions These data suggest that variation in these adipose hormones resulting from lower SHBG levels, and possibly, though less likely, greater androgenicity, may contribute to susceptibility for metabolic and cardiovascular outcomes during midlife in women. PMID:23592672

  14. Pericoronary adipose tissue: a novel therapeutic target in obesity-related coronary atherosclerosis.

    PubMed

    Mazurek, Tomasz; Opolski, Grzegorz

    2015-01-01

    Inflammation plays a crucial role in the development and destabilization of atherosclerotic plaques in coronary vessels. Adipose tissue is considered to act in paracrine manner, which modulates a number of physiological and pathophysiological processes. Perivascular adipose tissue has developed specific properties that distinguish it from the fat in other locations. Interestingly, its activity depends on several metabolic conditions associated with insulin resistance and weight gain. Particularly in obesity perivascular fat seems to change its character from a protective to a detrimental one. The present review analyzes literature in terms of the pathophysiology of atherosclerosis, with particular emphasis on inflammatory processes. Additionally, the authors summarize data about confirmed paracrine activity of visceral adipose tissue and especially about pericoronary fat influence on the vascular wall. The contribution of adiponectin, leptin and resistin is addressed. Experimental and clinical data supporting the thesis of outside-to-inside signaling in the pericoronary milieu are further outlined. Clinical implications of epicardial and pericoronary adipose tissue activity are also evaluated. The role of pericoronary adipose tissue in obesity-related atherosclerosis is highlighted. In conclusion, the authors discuss potential therapeutical implications of these novel phenomena, including adipokine imbalance in pericoronary adipose tissue in the setting of obesity, the influence of lifestyle and diet modification, pharmaceutical interventions and the growing role of microRNAs in adipogenesis, insulin resistance and obesity. Key teaching points: • adipose tissue as a source of inflammatory mediators • changes in the vascular wall as a result of outside-to-inside signaling • anatomy, physiology, and clinical implications of epicardial and pericoronary adipose tissue activity • adipokines and their role in obesity-related atherosclerosis • therapeutic

  15. 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

  16. Probiotics Modulate Intestinal Expression of Nuclear Receptor and Provide Counter-Regulatory Signals to Inflammation-Driven Adipose Tissue Activation

    PubMed Central

    Mencarelli, Andrea; Distrutti, Eleonora; Renga, Barbara; D'Amore, Claudio; Cipriani, Sabrina; Palladino, Giuseppe; Donini, Annibale; Ricci, Patrizia; Fiorucci, Stefano

    2011-01-01

    Background Adipocytes from mesenteric white adipose tissue amplify the inflammatory response and participate in inflammation-driven immune dysfunction in Crohn's disease by releasing proinflammatory mediators. Peroxisome proliferator-activated receptors (PPAR)-α and -γ, pregnane x receptor (PXR), farnesoid x receptor (FXR) and liver x-receptor (LXR) are ligand-activated nuclear receptor that provide counter-regulatory signals to dysregulated immunity and modulates adipose tissue. Aims To investigate the expression and function of nuclear receptors in intestinal and adipose tissues in a rodent model of colitis and mesenteric fat from Crohn's patients and to investigate their modulation by probiotics. Methods Colitis was induced by TNBS administration. Mice were administered vehicle or VSL#3, daily for 10 days. Abdominal fat explants obtained at surgery from five Crohn's disease patients and five patients with colon cancer were cultured with VSL#3 medium. Results Probiotic administration attenuated development of signs and symptoms of colitis, reduced colonic expression of TNFα, IL-6 and IFNγ and reserved colonic downregulation of PPARγ, PXR and FXR caused by TNBS. Mesenteric fat depots isolated from TNBS-treated animals had increased expression of inflammatory mediators along with PPARγ, FXR, leptin and adiponectin. These changes were prevented by VSL#3. Creeping fat and mesenteric adipose tissue from Crohn's patients showed a differential expression of PPARγ and FXR with both tissue expressing high levels of leptin. Exposure of these tissues to VSL#3 medium abrogates leptin release. Conclusions Mesenteric adipose tissue from rodent colitis and Crohn's disease is metabolically active and shows inflammation-driven regulation of PPARγ, FXR and leptin. Probiotics correct the inflammation-driven metabolic dysfunction. PMID:21829567

  17. Breast Cancer Cell Colonization of the Human Bone Marrow Adipose Tissue Niche1

    PubMed Central

    Templeton, Zach S.; Lie, Wen-Rong; Wang, Weiqi; Rosenberg-Hasson, Yael; Alluri, Rajiv V.; Tamaresis, John S.; Bachmann, Michael H.; Lee, Kitty; Maloney, William J.; Contag, Christopher H.; King, Bonnie L.

    2015-01-01

    BACKGROUND/OBJECTIVES: Bone is a preferred site of breast cancer metastasis, suggesting the presence of tissue-specific features that attract and promote the outgrowth of breast cancer cells. We sought to identify parameters of human bone tissue associated with breast cancer cell osteotropism and colonization in the metastatic niche. METHODS: Migration and colonization patterns of MDA-MB-231-fLuc-EGFP (luciferase-enhanced green fluorescence protein) and MCF-7-fLuc-EGFP breast cancer cells were studied in co-culture with cancellous bone tissue fragments isolated from 14 hip arthroplasties. Breast cancer cell migration into tissues and toward tissue-conditioned medium was measured in Transwell migration chambers using bioluminescence imaging and analyzed as a function of secreted factors measured by multiplex immunoassay. Patterns of breast cancer cell colonization were evaluated with fluorescence microscopy and immunohistochemistry. RESULTS: Enhanced MDA-MB-231-fLuc-EGFP breast cancer cell migration to bone-conditioned versus control medium was observed in 12/14 specimens (P = .0014) and correlated significantly with increasing levels of the adipokines/cytokines leptin (P = .006) and IL-1β (P = .001) in univariate and multivariate regression analyses. Fluorescence microscopy and immunohistochemistry of fragments underscored the extreme adiposity of adult human bone tissues and revealed extensive breast cancer cell colonization within the marrow adipose tissue compartment. CONCLUSIONS: Our results show that breast cancer cells migrate to human bone tissue-conditioned medium in association with increasing levels of leptin and IL-1β, and colonize the bone marrow adipose tissue compartment of cultured fragments. Bone marrow adipose tissue and its molecular signals may be important but understudied components of the breast cancer metastatic niche. PMID:26696367

  18. The Roles of Adipokines, Proinflammatory Cytokines, and Adipose Tissue Macrophages in Obesity-Associated Insulin Resistance in Modest Obesity and Early Metabolic Dysfunction

    PubMed Central

    Kim, Ji Min; Joung, Kyong Hye; Lee, Ju Hee; You, Bo Ram; Choi, Min Jeong; Ryu, Min Jeong; Ko, Young Bok; Lee, Min A.; Lee, Junguee; Ku, Bon Jeong; Shong, Minho; Lee, Ki Hwan; Kim, Hyun Jin

    2016-01-01

    The roles of adipokines, proinflammatory cytokines, and adipose tissue macrophages in obesity-associated insulin resistance have been explored in both animal and human studies. However, our current understanding of obesity-associated insulin resistance relies on studies of artificial metabolic extremes. The purpose of this study was to explore the roles of adipokines, proinflammatory cytokines, and adipose tissue macrophages in human patients with modest obesity and early metabolic dysfunction. We obtained omental adipose tissue and fasting blood samples from 51 females undergoing gynecologic surgery. We investigated serum concentrations of proinflammatory cytokines and adipokines as well as the mRNA expression of proinflammatory and macrophage phenotype markers in visceral adipose tissue using ELISA and quantitative RT-PCR. We measured adipose tissue inflammation and macrophage infiltration using immunohistochemical analysis. Serum levels of adiponectin and leptin were significantly correlated with HOMA-IR and body mass index. The levels of expression of MCP-1 and TNF-α in visceral adipose tissue were also higher in the obese group (body mass index ≥ 25). The expression of mRNA MCP-1 in visceral adipose tissue was positively correlated with body mass index (r = 0.428, p = 0.037) but not with HOMA-IR, whereas TNF-α in visceral adipose tissue was correlated with HOMA-IR (r = 0.462, p = 0.035) but not with body mass index. There was no obvious change in macrophage phenotype or macrophage infiltration in patients with modest obesity or early metabolic dysfunction. Expression of mRNA CD163/CD68 was significantly related to mitochondrial-associated genes and serum inflammatory cytokine levels of resistin and leptin. These results suggest that changes in the production of inflammatory biomolecules precede increased immune cell infiltration and induction of a macrophage phenotype switch in visceral adipose tissue. Furthermore, serum resistin and leptin have specific

  19. Liver but not adipose tissue is responsive to the pattern of enteral feeding

    PubMed Central

    Otero, Yolanda F.; Lundblad, Tammy M.; Ford, Eric A.; House, Lawrence M.; McGuinness, Owen P.

    2014-01-01

    Abstract Nutritional support is an important aspect of medical care, providing calories to patients with compromised nutrient intake. Metabolism has a diurnal pattern, responding to the light cycle and food intake, which in turn can drive changes in liver and adipose tissue metabolism. In this study, we assessed the response of liver and white adipose tissue (WAT) to different feeding patterns under nutritional support (total enteral nutrition or TEN). Mice received continuous isocaloric TEN for 10 days or equal calories of chow once a day (Ch). TEN was given either at a constant (CN, same infusion rate during 24 h) or variable rate (VN, 80% of calories fed at night, 20% at day). Hepatic lipogenesis and carbohydrate‐responsive element‐binding protein (ChREBP) expression increased in parallel with the diurnal feeding pattern. Relative to Ch, both patterns of enteral feeding increased adiposity. This increase was not associated with enhanced lipogenic gene expression in WAT; moreover, lipogenesis was unaffected by the feeding pattern. Surprisingly, leptin and adiponectin expression increased. Moreover, nutritional support markedly increased hepatic and adipose FGF21 expression in CN and VN, despite being considered a fasting hormone. In summary, liver but not WAT, respond to the pattern of feeding. While hepatic lipid metabolism adapts to the pattern of nutrient availability, WAT does not. Moreover, sustained delivery of nutrients in an isocaloric diet can cause adiposity without the proinflammatory state observed in hypercaloric feeding. Thus, the liver but not adipose tissue is responsive to the pattern of feeding behavior. PMID:24744913

  20. [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

  1. 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

  2. Sympathetic activation by chemical stimulation of white adipose tissues in rats.

    PubMed

    Shi, Zhen; Chen, Wei-Wei; Xiong, Xiao-Qing; Han, Ying; Zhou, Ye-Bo; Zhang, Feng; Gao, Xing-Ya; Zhu, Guo-Qing

    2012-03-01

    Injection of leptin into white adipose tissue (WAT) increases sympathetic outflow. The present study was designed to determine the effects of capsaicin and other chemicals in WAT on the sympathetic outflow and blood pressure and the roles of WAT afferents and hypothalamic paraventricular nucleus (PVN) in the adipose afferent reflex (AAR). The AAR was induced by injection of capsaicin, bradykinin, adenosine, adenosine triphosphate (ATP), or leptin into inguinal WAT (iWAT) or retroperitoneal WAT (rWAT) in anesthetized rats. The iWAT injection of capsaicin increased the renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) but not the heart rate. Bradykinin, adenosine, or leptin but not ATP in the iWAT caused similar effects to capsaicin on the RSNA and MAP. Intravenous, intramuscular, or intradermal injection of capsaicin had no significant effects on the RSNA and MAP. The effects of capsaicin in rWAT were similar to that in iWAT on the RSNA and MAP. Furthermore, injection of capsaicin into the iWAT increased the WAT afferent nerve activities, WAT efferent nerve activity, and brown adipose tissue efferent nerve activity. The iWAT denervation or chemical lesion of the PVN neurons with kainic acid abolished the AAR induced by the iWAT injection of capsaicin. These results indicate that the stimulation of iWAT afferents with capsaicin, bradykinin, adenosine, or leptin reflexly increases the RSNA and blood pressure. The iWAT afferents and the PVN are involved in the AAR induced by capsaicin in the iWAT. PMID:22223453

  3. 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.

  4. 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

  5. Interleukin-17A Differentially Induces Inflammatory and Metabolic Gene Expression in the Adipose Tissues of Lean and Obese Mice

    PubMed Central

    Qu, Yine; Zhang, Qiuyang; Ma, Siqi; Liu, Sen; Chen, Zhiquan; Mo, Zhongfu; You, Zongbing

    2016-01-01

    The functions of interleukin-17A (IL-17A) in adipose tissues and adipocytes have not been well understood. In the present study, male mice were fed with a regular diet (n = 6, lean mice) or a high-fat diet (n = 6, obese mice) for 30 weeks. Subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were analyzed for IL-17A levels. SAT and VAT were treated with IL-17A and analyzed for inflammatory and metabolic gene expression. Mouse 3T3-L1 pre-adipocytes were differentiated into adipocytes, followed with IL-17A treatment and analysis for inflammatory and metabolic gene expression. We found that IL-17A levels were higher in obese SAT than lean SAT; the basal expression of inflammatory and metabolic genes was different between SAT and VAT and between lean and obese adipose tissues. IL-17A differentially induced expression of inflammatory and metabolic genes, such as tumor necrosis factor α, Il-6, Il-1β, leptin, and glucose transporter 4, in adipose tissues of lean and obese mice. IL-17A also differentially induced expression of inflammatory and metabolic genes in pre-adipocytes and adipocytes, and IL-17A selectively activated signaling pathways in adipose tissues and adipocytes. These findings suggest that IL-17A differentially induces inflammatory and metabolic gene expression in the adipose tissues of lean and obese mice. PMID:27070576

  6. Interleukin-17A Differentially Induces Inflammatory and Metabolic Gene Expression in the Adipose Tissues of Lean and Obese Mice.

    PubMed

    Qu, Yine; Zhang, Qiuyang; Ma, Siqi; Liu, Sen; Chen, Zhiquan; Mo, Zhongfu; You, Zongbing

    2016-01-01

    The functions of interleukin-17A (IL-17A) in adipose tissues and adipocytes have not been well understood. In the present study, male mice were fed with a regular diet (n = 6, lean mice) or a high-fat diet (n = 6, obese mice) for 30 weeks. Subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were analyzed for IL-17A levels. SAT and VAT were treated with IL-17A and analyzed for inflammatory and metabolic gene expression. Mouse 3T3-L1 pre-adipocytes were differentiated into adipocytes, followed with IL-17A treatment and analysis for inflammatory and metabolic gene expression. We found that IL-17A levels were higher in obese SAT than lean SAT; the basal expression of inflammatory and metabolic genes was different between SAT and VAT and between lean and obese adipose tissues. IL-17A differentially induced expression of inflammatory and metabolic genes, such as tumor necrosis factor α, Il-6, Il-1β, leptin, and glucose transporter 4, in adipose tissues of lean and obese mice. IL-17A also differentially induced expression of inflammatory and metabolic genes in pre-adipocytes and adipocytes, and IL-17A selectively activated signaling pathways in adipose tissues and adipocytes. These findings suggest that IL-17A differentially induces inflammatory and metabolic gene expression in the adipose tissues of lean and obese mice. PMID:27070576

  7. 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

  8. The Impact of LEP G-2548A and LEPR Gln223Arg Polymorphisms on Adiposity, Leptin, and Leptin-Receptor Serum Levels in a Mexican Mestizo Population

    PubMed Central

    Chavarria-Avila, Efraín; Gomez-Bañuelos, Eduardo; Ruiz-Quezada, Sandra-Luz; Castro-Albarran, Jorge; Sánchez-López, Lizeth; Martín-Marquez, Beatriz Teresita; Navarro-Hernández, Rosa-Elena

    2015-01-01

    The polymorphisms in leptin (LEP G-2548A) and leptin-receptor (LEPR Gln223Arg) seem to influence obesity and lipid metabolism among others. The aim of this study was to investigate the effect of these polymorphisms on adiposity, leptin (sLeptin), and leptin-receptor (sLeptin-receptor) serum concentrations as well as inflammation markers. We included 382 adults originally from Western Mexico. They were genotyped by PCR-RFLP. Obese individuals showed higher sLeptin (58.2 ± 31.35 ng/mL) but lower sLeptin-receptor (12.6 ± 3.74 ng/mL) levels than normal weight ones (17.6 ± 14.62 ng/mL, 17.4 ± 4.62 ng/mL, resp.), P < 0.001. Obese subjects carriers of Arg/Arg genotype had more (P = 0.016) sLeptin-receptor (14.7 ± 4.96 ng/mL) and less (P = 0.004) sLeptin (44.0 ± 28.12 ng/mL) levels than Gln/Gln genotype (11.0 ± 2.92 ng/mL, 80.3 ± 33.24 ng/mL, resp.). Body fat mass was lower (P from 0.003 to 0.045) for A/A (36.5% ± 6.80) or Arg/Arg (36.8% ± 6.82) genotypes with respect to G/G (41.3% ± 5.52) and G/A (41.6% ± 5.61) or Gln/Gln (43.7% ± 4.74) and Gln/Arg (41.0% ± 5.52) genotypes carriers. Our results suggest that LEP -2548A and LEPR 223Arg could be genetic markers of less body fat mass accumulation in obese subjects from Western Mexico. PMID:26064921

  9. Leptin: a possible metabolic signal affecting reproduction.

    PubMed

    Spicer, L J

    2001-11-01

    Since its discovery in 1994, leptin, a protein hormone synthesized and secreted by adipose tissue, has been shown to regulate feed intake in several species including sheep and pigs. Although a nimiety of information exists regarding the physiological role of leptin in rodents and humans, the regulation and action of leptin in domestic animals is less certain. Emerging evidence in several species indicates that leptin may also affect the hypothalamo-pituitary-gonadal axis. Leptin receptor mRNA is present in the anterior pituitary and hypothalamus of several species, including sheep. In rats, effects of leptin on GnRH, LH and FSH secretion have been inconsistent, with leptin exhibiting both stimulatory and inhibitory action in vivo and in vitro. Evidence to support direct action of leptin at the level of the gonad indicates that the leptin receptor and its mRNA are present in ovarian tissue of several species, including cattle. These leptin receptors are functional, since leptin inhibits insulin-induced steroidogenesis of both granulosa and thecal cells of cattle in vitro. Leptin receptor mRNA is also found in the testes of rodents. As with the ovary, these receptors are functional, at least in rats, since leptin inhibits hCG-induced testosterone secretion by Leydig cells in vitro. During pregnancy, placental production of leptin may be a major contributor to the increase in maternal leptin in primates but not rodents. However, in both primates and rodents, leptin receptors exist in placental tissues and may regulate metabolism of the fetal-placental unit. As specific leptin immunoassays are developed for domestic animals, in vivo associations may then be made among leptin, body energy stores, dietary energy intake and reproductive function. This may lead to a more definitive role of leptin in domestic animal reproduction. PMID:11872320

  10. Leptin and reproductive function

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adipose tissue plays a dynamic role in whole-body homeostasis by acting as an endocrine organ. Collective evidence indicates a strong link between neural influences and adipocyte expression and secretion of leptin. Developmental changes in these relationships are considered important for pubertal ...

  11. Three-dimensional culture model for analyzing crosstalk between adipose tissue and hepatocytes.

    PubMed

    Nishijima-Matsunobu, Aki; Aoki, Shigehisa; Uchihashi, Kazuyoshi; Fujimoto, Kazuma; Toda, Shuji

    2013-06-01

    Systemic adipose tissue is involved in the pathophysiology of obesity-associated liver diseases. However, a method has not been established for analyzing the direct interaction between adipose tissue and hepatocytes. We describe a useful three-dimensional model comprising a collagen gel coculture system in which HepG2 hepatocytes are cultured on a gel layer with visceral adipose tissue fragments (VAT) or subcutaneous tissue samples (SAT). Male adipose tissues were obtained from 5-week-old Wistar rats and human autopsy cases. Cellular behavior was analyzed by electron microscopy, immunohistochemistry, Western blot, real-time reverse transcription plus the polymerase chain reaction and enzyme-linked immunosorbent assay. VAT significantly promoted lipid accumulation and apoptosis in HepG2 cells and suppressed their growth and differentiation compared with SAT. VAT produced higher concentrations of fatty acids (palmitate, oleate, linoleate) than SAT. HepG2 cells significantly decreased the production of these fatty acids in VAT. Only HepG2 cells treated with 250 μM palmitate replicated VAT-induced apoptosis. Neither VAT nor SAT affected lipotoxicity-associated signals of nuclear factor kappa B, c-Jun N-terminal kinase and inositol requiring enzyme-1α in HepG2 cells. HepG2 cells never affected adiponectin, leptin, or resistin production in VAT and SAT. The data indicate that our model actively creates adipose tissue and HepG2 hepatocyte interactions, suggesting that (1) VAT plays more critical roles in hepatocyte lipotoxicity than SAT; (2) palmitate but not adipokines, is partly involved in the mechanisms of VAT-induced lipotoxicity; (3) HepG2 cells might inhibit fatty acid production in VAT to protect themselves against lipotoxicity. Our model should serve in studies of interactions between adipose tissue and hepatocytes and of the mechanisms in obesity-related lipotoxicity and liver diseases. PMID:23512139

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. Microbiota depletion promotes browning of white adipose tissue and reduces obesity.

    PubMed

    Suárez-Zamorano, Nicolas; Fabbiano, Salvatore; Chevalier, Claire; Stojanović, Ozren; Colin, Didier J; Stevanović, Ana; Veyrat-Durebex, Christelle; Tarallo, Valentina; Rigo, Dorothée; Germain, Stéphane; Ilievska, Miroslava; Montet, Xavier; Seimbille, Yann; Hapfelmeier, Siegfried; Trajkovski, Mirko

    2015-12-01

    Brown adipose tissue (BAT) promotes a lean and healthy phenotype and improves insulin sensitivity. In response to cold or exercise, brown fat cells also emerge in the white adipose tissue (WAT; also known as beige cells), a process known as browning. Here we show that the development of functional beige fat in the inguinal subcutaneous adipose tissue (ingSAT) and perigonadal visceral adipose tissue (pgVAT) is promoted by the depletion of microbiota either by means of antibiotic treatment or in germ-free mice. This leads to improved glucose tolerance and insulin sensitivity and decreased white fat and adipocyte size in lean mice, obese leptin-deficient (ob/ob) mice and high-fat diet (HFD)-fed mice. Such metabolic improvements are mediated by eosinophil infiltration, enhanced type 2 cytokine signaling and M2 macrophage polarization in the subcutaneous white fat depots of microbiota-depleted animals. The metabolic phenotype and the browning of the subcutaneous fat are impaired by the suppression of type 2 cytokine signaling, and they are reversed by recolonization of the antibiotic-treated or germ-free mice with microbes. These results provide insight into the microbiota-fat signaling axis and beige-fat development in health and metabolic disease. PMID:26569380

  18. 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

  19. Evaluation of the synuclein-y (SNCG) gene as a PPARy target in murine adipocytes, dorsal root ganglia somatosensory neurons, and human adipose tissue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Synuclein-gamma is highly expressed in both adipocytes and peripheral nervous system (PNS) somatosensory neurons. Its mRNA is induced during adipogenesis, increased in obese human white adipose tissue (WAT), may be coordinately regulated with leptin, and is decreased following treatment of murine 3T...

  20. Leptin: a potential novel antidepressant.

    PubMed

    Lu, Xin-Yun; Kim, Chung Sub; Frazer, Alan; Zhang, Wei

    2006-01-31

    Leptin, a hormone secreted from adipose tissue, was originally discovered to regulate body weight. The localization of the leptin receptor in limbic structures suggests a potential role for leptin in emotional processes. Here, we show that rats exposed to chronic unpredictable stress and chronic social defeat exhibit low leptin levels in plasma. Systemic leptin treatment reversed the hedonic-like deficit induced by chronic unpredictable stress and improved behavioral despair dose-dependently in the forced swim test (FST), a model widely used for screening potential antidepressant efficacy. The behavioral effects of leptin in the FST were accompanied by increased neuronal activation in limbic structures, particularly in the hippocampus. Intrahippocampal infusion of leptin produced a similar antidepressant-like effect in the FST as its systemic administration. By contrast, infusion of leptin into the hypothalamus decreased body weight but had no effect on FST behavior. These findings suggest that: (i) impaired leptin production and secretion may contribute to chronic stress-induced depression-like phenotypes, (ii) the hippocampus is a brain site mediating leptin's antidepressant-like activity, and (iii) elevating leptin signaling in brain may represent a novel approach for the treatment of depressive disorders. PMID:16423896

  1. Leptin: A potential novel antidepressant

    PubMed Central

    Lu, Xin-Yun; Kim, Chung Sub; Frazer, Alan; Zhang, Wei

    2006-01-01

    Leptin, a hormone secreted from adipose tissue, was originally discovered to regulate body weight. The localization of the leptin receptor in limbic structures suggests a potential role for leptin in emotional processes. Here, we show that rats exposed to chronic unpredictable stress and chronic social defeat exhibit low leptin levels in plasma. Systemic leptin treatment reversed the hedonic-like deficit induced by chronic unpredictable stress and improved behavioral despair dose-dependently in the forced swim test (FST), a model widely used for screening potential antidepressant efficacy. The behavioral effects of leptin in the FST were accompanied by increased neuronal activation in limbic structures, particularly in the hippocampus. Intrahippocampal infusion of leptin produced a similar antidepressant-like effect in the FST as its systemic administration. By contrast, infusion of leptin into the hypothalamus decreased body weight but had no effect on FST behavior. These findings suggest that: (i) impaired leptin production and secretion may contribute to chronic stress-induced depression-like phenotypes, (ii) the hippocampus is a brain site mediating leptin's antidepressant-like activity, and (iii) elevating leptin signaling in brain may represent a novel approach for the treatment of depressive disorders. PMID:16423896

  2. 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

  3. 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

  4. Leptin and pregnancy outcome.

    PubMed

    Kratzsch, J; Höckel, M; Kiess, W

    2000-12-01

    Leptin, a recently discovered hormone that is involved in the regulation of body weight, appears to be one of the hormonal factors that signal the body's readiness for sexual maturation and reproduction to the brain. The present review focuses on clinical and experimental studies that describe the roles of maternal and foetal leptin as predictive factors for the physiological and pathophysiological development of the foetus during pregnancy, assisted reproduction and neonatal life. Through evaluating alterations of maternal serum leptin levels, a physiological hyperleptinaemia has been observed to occur, particularly during the second and third trimesters of pregnancy, which is not associated with a decreased food intake or reduced metabolic activity in the pregnant women. This state of leptin resistance is comparable to the condition in obesity. In contrast, hypoleptinaemia is suggested to be an indicator for the cessation of pregnancy, either naturally at term or as a result of pathology at any time during gestation. Thus, an appropriate maternal leptin level seems to be a prerequisite for a normal pregnancy. The main source of foetal leptin is the still immature foetal adipose tissue. As intrauterine growth has been found to be independently associated with cord blood leptin level, it has been suggested that leptin plays a role as a regulator of foetal growth. During assisted reproduction cycles leptin levels in the follicular fluid of patients may be also of predictive value, with low levels predicting therapeutic failure. Finally, the relevance of leptin to postnatal development is reviewed; leptin may be important for regulation of satiety and peripheral metabolism. In summary, leptin appears to be an important permissive factor that is involved in female reproduction. PMID:11128413

  5. Characterization of In Vitro Engineered Human Adipose Tissues: Relevant Adipokine Secretion and Impact of TNF-α

    PubMed Central

    Aubin, Kim; Safoine, Meryem; Proulx, Maryse; Audet-Casgrain, Marie-Alice; Côté, Jean-François; Têtu, Félix-André; Roy, Alphonse; Fradette, Julie

    2015-01-01

    Representative modelling of human adipose tissue functions is central to metabolic research. Tridimensional models able to recreate human adipogenesis in a physiological tissue-like context in vitro are still scarce. We describe the engineering of white adipose tissues reconstructed from their cultured adipose-derived stromal precursor cells. We hypothesize that these reconstructed tissues can recapitulate key functions of AT under basal and pro-inflammatory conditions. These tissues, featuring human adipocytes surrounded by stroma, were stable and metabolically active in long-term cultures (at least 11 weeks). Secretion of major adipokines and growth factors by the reconstructed tissues was determined and compared to media conditioned by human native fat explants. Interestingly, the secretory profiles of the reconstructed adipose tissues indicated an abundant production of leptin, PAI-1 and angiopoietin-1 proteins, while higher HGF levels were detected for the human fat explants. We next demonstrated the responsiveness of the tissues to the pro-inflammatory stimulus TNF-α, as reflected by modulation of MCP-1, NGF and HGF secretion, while VEGF and leptin protein expression did not vary. TNF-α exposure induced changes in gene expression for adipocyte metabolism-associated mRNAs such as SLC2A4, FASN and LIPE, as well as for genes implicated in NF-κB activation. Finally, this model was customized to feature adipocytes representative of progressive stages of differentiation, thereby allowing investigations using newly differentiated or more mature adipocytes. In conclusion, we produced tridimensional tissues engineered in vitro that are able to recapitulate key characteristics of subcutaneous white adipose tissue. These tissues are produced from human cells and their neo-synthesized matrix elements without exogenous or synthetic biomaterials. Therefore, they represent unique tools to investigate the effects of pharmacologically active products on human stromal cells

  6. Prunus mume and Lithospermum erythrorhizon Extracts Synergistically Prevent Visceral Adiposity by Improving Energy Metabolism through Potentiating Hypothalamic Leptin and Insulin Signalling in Ovariectomized Rats.

    PubMed

    Ko, Byoung-Seob; Kim, Da Sol; Kang, Suna; Ryuk, Jin Ah; Park, Sunmin

    2013-01-01

    We investigated the antiobesity and hypoglycemic properties of Prunus mume Sieb. et Zucc (PMA; Japanese apricot) and Lithospermum erythrorhizon Sieb. et Zucc (LES; gromwell) extracts in ovariectomized (OVX) rats that impaired energy and glucose homeostasis. OVX rats consumed either 5% dextrose, 5% PMA extract, 5% LES extract, or 2.5% PMA+2.5% LES extract in the high fat diet. After 8 weeks of treatment, PMA+LES prevented weight gain and visceral fat accumulation in OVX rats by lowering daily food intake and increasing energy expenditure and fat oxidation. PMA+LES prevented the attenuation of leptin and insulin signaling by increasing the expression of leptin receptor in the hypothalamus in OVX rats. PMA+LES significantly reversed the decrease of energy expenditure in OVX rats by increasing expression of UCP-1 in the brown adipose tissues and UCP-2 and UCP-3 in the quadriceps muscles. PMA+LES also increased CPT-1 expression and decreased FAS, ACC, and SREBP-1c in the liver and quadriceps muscles to result in reducing triglyceride accumulation. PMA+LES improved insulin sensitivity in OVX rats. In conclusion, PMA+LES synergistically prevented the impairment of energy, lipid, and glucose metabolism by OVX through potentiating hypothalamic leptin and insulin signaling. PMA+LES may be a useful intervention for alleviating the symptoms of menopause in women. PMID:24319483

  7. 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

  8. 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...

  9. 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...

  10. 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...

  11. 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 ...

  12. Increased expression of FGF1-mediated signaling molecules in adipose tissue of obese mice.

    PubMed

    Choi, Youngshim; Jang, Suhyeon; Choi, Myung-Sook; Ryoo, Zae Young; Park, Taesun

    2016-06-01

    Fibroblast growth factors (FGFs) are pleiotropic growth factors that control cell proliferation, migration, and differentiation. Herein, we evaluated whether visceral adiposity of mice is accompanied by the alteration of signaling molecules mediated by fibroblast growth factor receptor 1 (FGFR1) induced by using two different male C57BL/6J mice models of obesity namely high-fat diet (HFD)-induced obesity for 12 weeks or mice with genetic deletion of leptin (ob/ob). Both HFD-fed and ob/ob mice exhibited significantly higher messenger RNA (mRNA) levels of FGF1, cyclin D (cycD), transcription factor E2F1, peroxisome proliferator-activated receptor-gamma 2 (PPAR-γ2), CCAAT-enhancer-binding protein alpha (C/EBPα), and adipocyte protein 2 (aP2) genes in their epididymal adipose tissues compared to those of the normal diet (ND)-fed and lean control mice, respectively. In addition, immunoblot analyses of the epididymal adipose tissues revealed that both mice exposed to HFD and ob/ob mice exhibited elevated phosphorylation of FGFR1, extracellular-signal-regulated kinase (ERK), and retinoblastoma (Rb) proteins. These data support the notion that FGF1-mediated signaling represents an important signaling cascade related to adipogenesis, at least partially, among other known signaling pathways. These new findings regarding the molecular mechanisms controlling adipose tissue plasticity provide a novel insight about the functional network with potential therapeutic application against obesity. PMID:26847131

  13. 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

  14. 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

  15. FNDC5 expression and circulating irisin levels are modified by diet and hormonal conditions in hypothalamus, adipose tissue and muscle.

    PubMed

    Varela-Rodríguez, B M; Pena-Bello, L; Juiz-Valiña, P; Vidal-Bretal, B; Cordido, F; Sangiao-Alvarellos, S

    2016-01-01

    Irisin is processed from fibronectin type III domain-containing protein 5 (FNDC5). However, a controversy exists concerning irisin origin, regulation and function. To elucidate the relationship between serum irisin and FNDC5 mRNA expression levels, we evaluated plasma irisin levels and FNDC5 gene expression in the hypothalamus, gastrocnemius muscle and different depots of adipose tissue in models of altered metabolism. In normal rats, blood irisin levels diminished after 48-h fast and with leptin, insulin and alloxan treatments, and serum irisin concentrations increased in diabetic rats after insulin treatment and acute treatments of irisin increased blood insulin levels. No changes were observed during long-term experiments with different diets. We suggested that levels of circulating irisin are the result of the sum of the irisin produced by different depots of adipose tissue and skeletal muscle. This study shows for the first time that there are differences in FNDC5 expression depending on white adipose tissue depots. Moreover, a considerable decrease in visceral and epididymal adipose tissue depots correlated with increased FNDC5 mRNA expression levels, probably in an attempt to compensate the decrease that occurs in their mass. Hypothalamic FNDC5 expression did not change for any of the tested diets but increased with leptin, insulin and metformin treatments suggesting that the regulation of central and peripheral FNDC5/irisin expression and functions are different. PMID:27432282

  16. FNDC5 expression and circulating irisin levels are modified by diet and hormonal conditions in hypothalamus, adipose tissue and muscle

    PubMed Central

    Varela-Rodríguez, B. M.; Pena-Bello, L.; Juiz-Valiña, P.; Vidal-Bretal, B.; Cordido, F.; Sangiao-Alvarellos, S.

    2016-01-01

    Irisin is processed from fibronectin type III domain-containing protein 5 (FNDC5). However, a controversy exists concerning irisin origin, regulation and function. To elucidate the relationship between serum irisin and FNDC5 mRNA expression levels, we evaluated plasma irisin levels and FNDC5 gene expression in the hypothalamus, gastrocnemius muscle and different depots of adipose tissue in models of altered metabolism. In normal rats, blood irisin levels diminished after 48-h fast and with leptin, insulin and alloxan treatments, and serum irisin concentrations increased in diabetic rats after insulin treatment and acute treatments of irisin increased blood insulin levels. No changes were observed during long-term experiments with different diets. We suggested that levels of circulating irisin are the result of the sum of the irisin produced by different depots of adipose tissue and skeletal muscle. This study shows for the first time that there are differences in FNDC5 expression depending on white adipose tissue depots. Moreover, a considerable decrease in visceral and epididymal adipose tissue depots correlated with increased FNDC5 mRNA expression levels, probably in an attempt to compensate the decrease that occurs in their mass. Hypothalamic FNDC5 expression did not change for any of the tested diets but increased with leptin, insulin and metformin treatments suggesting that the regulation of central and peripheral FNDC5/irisin expression and functions are different. PMID:27432282

  17. 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

  18. Adipose tissue and adipokines--energy regulation from the human perspective.

    PubMed

    Trayhurn, Paul; Bing, Chen; Wood, I Stuart

    2006-07-01

    There has been a rapid rise in the incidence of obesity, primarily as a result of changes in lifestyle (diet and activity levels). Obesity has provided considerable impetus for the investigation of the fundamental mechanisms involved in the regulation of energy balance. Important developments include the identification of novel factors involved in the control of appetite, such as ghrelin, orexin A, and the endogenous cannabinoids, and the emergence of the concept of "nonexercise activity thermogenesis" (NEAT) provided new perspectives on energy expenditure. Studies on white adipose tissue have led to the recognition that it is an important endocrine organ, communicating with the brain and peripheral tissues through the secretion of leptin and other adipokines. There is a rapidly expanding list of protein factors released by white adipose tissue, including the key hormone, adiponectin. Of particular note is the range of cytokines, chemokines, and other inflammation-related proteins secreted by white fat as tissue mass rises; indeed, obesity is characterized by chronic mild inflammation. The adipokines provide an extensive network of communication both within adipose tissue and with other organs, and some are implicated directly in the pathologies associated with obesity, particularly the metabolic syndrome. Although the focus remains very much on obesity in humans, the disorder and its sequelae are also a growing concern in companion animals. PMID:16772463

  19. 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

  20. 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

  1. Chemerin gene expression is regulated by food restriction and food restriction-refeeding in rat adipose tissue but not in liver.

    PubMed

    Stelmanska, Ewa; Sledzinski, Tomasz; Turyn, Jacek; Presler, Malgorzata; Korczynska, Justyna; Swierczynski, Julian

    2013-02-10

    Chemerin is an adipokine that regulates adipocyte development and metabolism as well as inflammatory and immune function of some cells. Although chemerin may be linked to obesity and related diseases, little is known about the nutritional regulation of chemerin gene expression. We investigated the effect of prolonged food restriction, a common approach in treating obesity and related diseases, and prolonged food restriction-refeeding on chemerin gene expression in rat white adipose tissue and liver. The prolonged food restriction was accompanied by an approximately 2-fold decrease in chemerin mRNA level in rat white adipose tissue. Upon refeeding, an increase (approximately 8-fold as compared to rats maintained on restricted diet and 4-fold as compared to control) in chemerin mRNA level in white adipose tissue was found. Surprisingly, no effect of food restriction and food restriction-refeeding on chemerin mRNA level in the liver was found. Chemerin mRNA level in adipose tissue was positively correlated with serum insulin concentration. Moreover insulin increased significantly chemerin gene expression in primary rat adipocytes. The changes in chemerin mRNA level in adipose tissue and serum chemerin concentrations were associated with changes in serum leptin and free fatty acid concentrations. Collectively, the data presented here indicate that chemerin gene expression is regulated by nutritional status in rat adipose tissue but not in liver. It seems that insulin plays important role in stimulation of chemerin gene expression in adipose tissue. However, changes in serum leptin and free fatty acids concentrations after food restriction-refeeding suggest that the role of these factors in the regulation of chemerin gene expression in adipose tissue cannot be excluded. Lack of the effect of food restriction and food restriction-refeeding on liver chemerin gene expression suggests that adipose tissue is the dietary modifiable source of serum chemerin concentration. PMID

  2. 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

  3. Gene expression changes in adipose tissue with diet- and/or exercise-induced weight loss

    PubMed Central

    Campbell, Kristin L.; Foster-Schubert, Karen E.; Makar, Karen W.; Kratz, Mario; Hagman, Derek; Schur, Ellen A.; Habermann, Nina; Horton, Marc; Abbenhardt, Clare; Kuan, Ling-Yu; Xiao, Liren; Davison, Jerry; Morgan, Martin; Wang, Ching-Yun; Duggan, Catherine; McTiernan, Anne; Ulrich, Cornelia M.

    2013-01-01

    Adipose tissue plays a role in obesity-related cancers via increased production of inflammatory factors, steroid hormones, and altered adipokines. The impact of weight loss on adipose-tissue gene expression may provide insights into pathways linking obesity with cancer risk. We conducted an ancillary study within a randomized trial of diet, exercise, or combined diet+exercise vs. control among overweight/obese postmenopausal women. In 45 women, subcutaneous adipose-tissue biopsies were performed at baseline and after 6 months and changes in adipose-tissue gene expression were determined by microarray with an emphasis on pre-specified candidate pathways, as well as by unsupervised clustering of >37,000 transcripts (Illumina). Analyses were conducted first by randomization group, and then by degree of weight change at 6-months in all women combined. At 6 months, diet, exercise and diet+exercise participants lost a mean of 8.8 kg, 2.5 kg, and 7.9 kg (all p<0.05 vs. no change in controls). There was no significant change in candidate-gene expression by intervention group. In analysis by weight-change category, greater weight loss was associated a decrease in 17β-hydroxysteroid dehydrogenase-1 (HSD17B1, p-trend<0.01) and leptin (LEP, p-trend<0.01) expression, and marginally significant increased expression of estrogen receptor-1 (ESR1, p-trend=0.08) and insulin-like growth factor binding protein-3 (IGFBP3, p-trend=0.08). Unsupervised clustering revealed 83 transcripts with statistically significant changes. Multiple gene-expression changes correlated with changes in associated serum biomarkers. Weight-loss was associated with changes in adipose-tissue gene expression after 6 months, particularly in two pathways postulated to link obesity and cancer, i.e., steroid-hormone metabolism and IGF signaling. PMID:23341572

  4. 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

  5. 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

  6. 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.

  7. 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

  8. 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

  9. Depot- and sex-specific effects of maternal obesity in offspring's adipose tissue.

    PubMed

    Lecoutre, Simon; Deracinois, Barbara; Laborie, Christine; Eberlé, Delphine; Guinez, Céline; Panchenko, Polina E; Lesage, Jean; Vieau, Didier; Junien, Claudine; Gabory, Anne; Breton, Christophe

    2016-07-01

    According to the Developmental Origin of Health and Disease (DOHaD) concept, alterations of nutrient supply in the fetus or neonate result in long-term programming of individual body weight (BW) setpoint. In particular, maternal obesity, excessive nutrition, and accelerated growth in neonates have been shown to sensitize offspring to obesity. The white adipose tissue may represent a prime target of metabolic programming induced by maternal obesity. In order to unravel the underlying mechanisms, we have developed a rat model of maternal obesity using a high-fat (HF) diet (containing 60% lipids) before and during gestation and lactation. At birth, newborns from obese dams (called HF) were normotrophs. However, HF neonates exhibited a rapid weight gain during lactation, a key period of adipose tissue development in rodents. In males, increased BW at weaning (+30%) persists until 3months of age. Nine-month-old HF male offspring was normoglycemic but showed mild glucose intolerance, hyperinsulinemia, and hypercorticosteronemia. Despite no difference in BW and energy intake, HF adult male offspring was predisposed to fat accumulation showing increased visceral (gonadal and perirenal) depots weights and hyperleptinemia. However, only perirenal adipose tissue depot exhibited marked adipocyte hypertrophy and hyperplasia with elevated lipogenic (i.e. sterol-regulated element binding protein 1 (Srebp1), fatty acid synthase (Fas), and leptin) and diminished adipogenic (i.e. peroxisome proliferator-activated receptor gamma (Pparγ), 11β-hydroxysteroid dehydrogenase type 1 (11β-Hds1)) mRNA levels. By contrast, very few metabolic variations were observed in HF female offspring. Thus, maternal obesity and accelerated growth during lactation program offspring for higher adiposity via transcriptional alterations of visceral adipose tissue in a depot- and sex-specific manner. PMID:27122310

  10. Adipoparacrinology--vascular periadventitial adipose tissue (tunica adiposa) as an example.

    PubMed

    Chaldakov, George N; Beltowsky, Jerzy; Ghenev, Peter I; Fiore, Marco; Panayotov, Plamen; Rančič, Gorana; Aloe, Luigi

    2012-03-01

    Human adipose tissue is partitioned into two large depots (subcutaneous and visceral), and many small depots associated with internal organs, e.g. heart, blood vessels, major lymph nodes, pancreas, prostate gland and ovaries. Since the adipose 'Big Bang' led to the discovery of leptin (Zhang, Proenca, Maffei, Barone, Leopold and Friedman, Nature 1994;372:425-32), adipose tissue has been seen not merely as a lipid store, but as a secretory - endocrine and paracrine - organ, particularly in the pathogenesis of a number of diseases. Accordingly, two major sub-fields of adipobiology have emerged, viz. adipoendocrinology and adipoparacrinology, the latter herein being illustrated by PAAT (periadventitial adipose tissue) in vascular walls. A long-standing paradigm holds that the vascular wall consists of three coats, tunica intima, tunica media and tunica adventitia. It is now imperative that 'to further elucidate vascular function, we should no longer, as hitherto, separate adventitia and PAAT from the vascular wall, but keep them attached and in place, and subject to thorough examination' (Chaldakov, Fiore, Ghenev, Stankulov and Aloe, Int Med J 2000;7:43-9; Chaldakov, Stankulov and Aloe, Atherosclerosis 2001;154:237-8; Chaldakov GN, Stankulov IS, Fiore M, Ghenev PI and Aloe L, Atherosclerosis 2001;159:57-66). From the available data, we propose that it is time to rethink about vascular wall composition, and suggest that the PAAT may be considered the fourth and outermost vascular coat, hence, tunica adiposa (regarding the proximal segment of coronary artery, it is the innermost part of the EAT (epicardial adipose tissue) situated around the coronary adventitia). Its significance in the pathogenesis and therapy of CMDs (cardiometabolic diseases), particularly atherosclerosis and hypertension, requires further basic, translational and clinical studies. PMID:22150107

  11. 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

  12. 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.

  13. 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

  14. 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

  15. Microbiota depletion promotes browning of white adipose tissue and reduces obesity

    PubMed Central

    Chevalier, Claire; Stojanović, Ozren; Colin, Didier J.; Stevanović, Ana; Veyrat-Durebex, Christelle; Tarallo, Valentina; Rigo, Dorothée; Germain, Stéphane; Ilievska, Miroslava; Montet, Xavier; Seimbille, Yann; Hapfelmeier, Siegfried; Trajkovski, Mirko

    2015-01-01

    Brown adipose tissue (BAT) promotes a lean and healthy phenotype and improves insulin sensitivity1. In response to cold or exercise brown fat cells also emerge in the white adipose tissue (named beige cells), a process known as browning2,3,4. Here, we show that the development of functional beige fat is promoted by microbiota depletion either by antibiotic treatment or in germ-free mice within the inguinal subcutaneous and perigonadal visceral adipose tissues (ingSAT and pgVAT, respectively). This leads to improved glucose tolerance, insulin sensitivity and decreased white fat and adipocyte size in lean mice and obese leptin-deficient (ob/ob) and high fat diet (HFD)-fed mice. These metabolic improvements are mediated by eosinophil infiltration and enhanced type 2 cytokine signaling and M2 macrophage polarization in the subcutaneous white fat depots of microbiota-depleted animals. The metabolic phenotype and the browning of the subcutaneous fat are impaired by suppression of the type 2 signaling and are reversed by recolonization of the antibiotic-treated, or the germ-free mice with microbes. These results provide insight into microbiota-fat signaling axis and beige fat development in health and metabolic disease. PMID:26569380

  16. Pref-1 and adipokine expression in adipose tissues of GK and Zucker rats.

    PubMed

    Barbu, Andreea; Hedlund, Gabriella Persdotter; Lind, Jenny; Carlsson, Carina

    2009-02-27

    In view of the central role of preadipocyte factor-1, adiponectin and leptin in white adipose tissue function, the aim of the present study was to analyze the mRNA expression of these proteins and of the inflammatory markers interleukin-6 and tumor necrosis factor-alpha in visceral and subcutaneous fat pads of rats with different metabolic disorders. We demonstrated highly divergent expression of preadipocyte factor-1, upregulated expression of adiponectin, interleukin-6 and TNF-alpha mRNA in adipose tissues of the diabetic Goto Kakizaki rat compared to the obese Zucker rat. This was correlated to an increased number of large adipocytes and serum levels of adiponectin. Furthermore, in all four strains studied (as above plus Wistar Furth and Zucker Lean), significant heterogeneity was evident in adipokine expression within specific adipose tissues previously defined as belonging to the visceral or subcutaneous fat depots. These results suggest that significantly increased levels of inflammation and redistribution of adipocyte size are mechanisms contributing to the development of type 2 diabetes in the GK rat. PMID:19084046

  17. 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

  18. 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

  19. 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

  20. Chronic social isolation is associated with metabolic gene expression changes specific to mammary adipose tissue

    PubMed Central

    Volden, Paul A.; Wonder, Erin L.; Skor, Maxwell N.; Carmean, Christopher M.; Patel, Feenalie N.; Ye, Honggang; Kocherginsky, Masha; McClintock, Martha K.; Brady, Matthew J.; Conzen, Suzanne D.

    2013-01-01

    Chronic social isolation is linked to increased mammary tumor growth in rodent models of breast cancer. In the C3(1)/SV40 T-antigen FVB/N (TAg) mouse model of “triple-negative” breast cancer, the heightened stress response elicited by social isolation has been associated with increased expression of metabolic genes in the mammary gland before invasive tumors develop (i.e. during the in situ carcinoma stage). To further understand the mechanisms underlying how accelerated mammary tumor growth is associated with social isolation, we separated the mammary gland adipose tissue from adjacent ductal epithelial cells and analyzed individual cell types for changes in metabolic gene expression. Specifically, increased expression of the key metabolic genes Acaca, Hk2 and Acly was found in the adipocyte, rather than the epithelial fraction. Surprisingly, metabolic gene expression was not significantly increased in visceral adipose depots of socially isolated female mice. As expected, increased metabolic gene expression in the mammary adipocytes of socially isolated mice coincided with increased glucose metabolism, lipid synthesis, and leptin secretion from this adipose depot. Furthermore, application of media that had been cultured with isolated mouse mammary adipose tissue (conditioned media) resulted in increased proliferation of mammary cancer cells relative to group-housed conditioned media. These results suggest that exposure to a chronic stressor (social isolation) results in specific metabolic reprogramming in mammary gland adipocytes that in turn contributes to increased proliferation of adjacent pre-invasive malignant epithelial cells. Metabolites and/or tumor growth-promoting proteins secreted from adipose tissue could identify biomarkers and/or targets for preventive intervention in breast cancer. PMID:23780289

  1. 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

  2. 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

  3. 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

  4. 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...

  5. Leptin and reproductive function.

    PubMed

    Hausman, Gary J; Barb, C Richard; Lents, Clay A

    2012-10-01

    Adipose tissue plays a dynamic role in whole-body energy homeostasis by acting as an endocrine organ. Collective evidence indicates a strong link between neural influences and adipocyte expression and secretion of leptin. Developmental changes in these relationships are considered important for pubertal transition in reproductive function. Leptin augments secretion of gonadotropin hormones, which are essential for initiation and maintenance of normal reproductive function, by acting centrally at the hypothalamus to regulate gonadotropin-releasing hormone (GnRH) neuronal activity and secretion. The effects of leptin on GnRH are mediated through interneuronal pathways involving neuropeptide-Y, proopiomelanocortin and kisspeptin. Increased infertility associated with diet induced obesity or central leptin resistance are likely mediated through the kisspeptin-GnRH pathway. Furthermore, Leptin regulates reproductive function by altering the sensitivity of the pituitary gland to GnRH and acting at the ovary to regulate follicular and luteal steroidogenesis. Thus leptin serves as a putative signal that links metabolic status with the reproductive axis. The intent of this review is to examine the biological role of leptin with energy metabolism, and reproduction. PMID:22980196

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. Influence of birth weight and gender on lipid status and adipose tissue gene expression in lambs.

    PubMed

    Wallace, Jacqueline M; Milne, John S; Aitken, Raymond P; Adam, Clare L

    2014-08-01

    Intrauterine growth restriction (IUGR) is a risk factor for obesity, particularly when offspring are born into an unrestricted nutritional environment. In this study, we investigated the impact of IUGR and gender on circulating lipids and on expression of adipogenic, lipogenic and adipokine genes in perirenal adipose tissue. Singleton lambs born to overnourished adolescent dams were normal birth weight (N) or IUGR (32% lower birth weight due to placental insufficiency). IUGR lambs exhibited increased fractional growth rates but remained smaller than N lambs at necropsy (d77). At 48 days, fasting plasma triglycerides, non-esterified fatty acids and glycerol were elevated predominantly in IUGR males. Body fat content was independent of prenatal growth but higher in females than in males. In perirenal fat, relative to male lambs, females had larger adipocytes; higher lipoprotein lipase, fatty acid synthase and leptin and lower IGF1, IGF2, IGF1R, IGF2R and hormone-sensitive lipase mRNA expression levels, and all were independent of prenatal growth category; peroxisome proliferator-activated receptor gamma and glycerol-3-phosphate dehydrogenase (G3PDH) mRNA expression were not affected by IUGR or gender. Adiposity indices were inversely related to G3PDH mRNA expression, and for the population as a whole the expression of IGF system genes in perirenal fat was negatively correlated with plasma leptin, fat mass and adipocyte size, and positively correlated with circulating IGF1 levels. Higher plasma lipid levels in IUGR males may predict later adverse metabolic health and obesity, but in early postnatal life gender has the dominant influence on adipose tissue gene expression, reflecting the already established sexual dimorphism in body composition. PMID:24928206

  12. Immunohistochemical distribution of leptin in kidney tissues of melatonin treated diabetic rats.

    PubMed

    Elis Yildiz, S; Deprem, T; Karadag Sari, E; Bingol, S A; Koral Tasci, S; Aslan, S; Nur, G; Sozmen, M

    2015-05-01

    We examined using immunohistochemistry the distribution of leptin in kidney tissues of melatonin treated, streptozotocin (STZ) diabetic rats. The animals were divided into five groups: control, sham, melatonin-treated, diabetic and melatonin-treated diabetic. Kidney sections were prepared and stained with hematoxylin and eosin, and Crossman's triple staining for histological examination. The immunohistochemical localization of leptin in the kidney tissue was determined using the streptavidin-biotin-peroxidase method. We determined that on days 7 and 14, the leptin immunoreactivity of the diabetic and melatonin-treated diabetic groups was weaker than for the other groups. Weak immunoreactivity was found in the proximal and distal tubules of the kidney in the diabetic and melatonin-treated diabetic groups on days 7 and 14, and strong immunoreactivity was found in the control, sham and melatonin groups. Melatonin application had no significant effect on leptin production in the kidney tissues of diabetic rats. PMID:25539049

  13. The role of leptin in central nervous system diseases

    PubMed Central

    Li, Xiao-Mei; Yan, Hai-Jing; Guo, Yi-Shan

    2016-01-01

    Leptin is a peptide hormone produced by adipose tissue and acts in brain centers to control critical physiological functions. Leptin receptors are especially abundant in the hypothalamus and trigger specific neuronal subpopulations, and activate several intracellular signaling events, including the JAK/STAT, MAPK, PI3K, and mTOR pathway. Although most studies focus on its role in energy intake and expenditure, leptin also plays a critical role in many central nervous system diseases. PMID:26885866

  14. 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

  15. Genome-wide meta-analysis uncovers novel loci influencing circulating leptin levels.

    PubMed

    Kilpeläinen, Tuomas O; Carli, Jayne F Martin; Skowronski, Alicja A; Sun, Qi; Kriebel, Jennifer; Feitosa, Mary F; Hedman, Åsa K; Drong, Alexander W; Hayes, James E; Zhao, Jinghua; Pers, Tune H; Schick, Ursula; Grarup, Niels; Kutalik, Zoltán; Trompet, Stella; Mangino, Massimo; Kristiansson, Kati; Beekman, Marian; Lyytikäinen, Leo-Pekka; Eriksson, Joel; Henneman, Peter; Lahti, Jari; Tanaka, Toshiko; Luan, Jian'an; Del Greco M, Fabiola; Pasko, Dorota; Renström, Frida; Willems, Sara M; Mahajan, Anubha; Rose, Lynda M; Guo, Xiuqing; Liu, Yongmei; Kleber, Marcus E; Pérusse, Louis; Gaunt, Tom; Ahluwalia, Tarunveer S; Ju Sung, Yun; Ramos, Yolande F; Amin, Najaf; Amuzu, Antoinette; Barroso, Inês; Bellis, Claire; Blangero, John; Buckley, Brendan M; Böhringer, Stefan; I Chen, Yii-Der; de Craen, Anton J N; Crosslin, David R; Dale, Caroline E; Dastani, Zari; Day, Felix R; Deelen, Joris; Delgado, Graciela E; Demirkan, Ayse; Finucane, Francis M; Ford, Ian; Garcia, Melissa E; Gieger, Christian; Gustafsson, Stefan; Hallmans, Göran; Hankinson, Susan E; Havulinna, Aki S; Herder, Christian; Hernandez, Dena; Hicks, Andrew A; Hunter, David J; Illig, Thomas; Ingelsson, Erik; Ioan-Facsinay, Andreea; Jansson, John-Olov; Jenny, Nancy S; Jørgensen, Marit E; Jørgensen, Torben; Karlsson, Magnus; Koenig, Wolfgang; Kraft, Peter; Kwekkeboom, Joanneke; Laatikainen, Tiina; Ladwig, Karl-Heinz; LeDuc, Charles A; Lowe, Gordon; Lu, Yingchang; Marques-Vidal, Pedro; Meisinger, Christa; Menni, Cristina; Morris, Andrew P; Myers, Richard H; Männistö, Satu; Nalls, Mike A; Paternoster, Lavinia; Peters, Annette; Pradhan, Aruna D; Rankinen, Tuomo; Rasmussen-Torvik, Laura J; Rathmann, Wolfgang; Rice, Treva K; Brent Richards, J; Ridker, Paul M; Sattar, Naveed; Savage, David B; Söderberg, Stefan; Timpson, Nicholas J; Vandenput, Liesbeth; van Heemst, Diana; Uh, Hae-Won; Vohl, Marie-Claude; Walker, Mark; Wichmann, Heinz-Erich; Widén, Elisabeth; Wood, Andrew R; Yao, Jie; Zeller, Tanja; Zhang, Yiying; Meulenbelt, Ingrid; Kloppenburg, Margreet; Astrup, Arne; Sørensen, Thorkild I A; Sarzynski, Mark A; Rao, D C; Jousilahti, Pekka; Vartiainen, Erkki; Hofman, Albert; Rivadeneira, Fernando; Uitterlinden, André G; Kajantie, Eero; Osmond, Clive; Palotie, Aarno; Eriksson, Johan G; Heliövaara, Markku; Knekt, Paul B; Koskinen, Seppo; Jula, Antti; Perola, Markus; Huupponen, Risto K; Viikari, Jorma S; Kähönen, Mika; Lehtimäki, Terho; Raitakari, Olli T; Mellström, Dan; Lorentzon, Mattias; Casas, Juan P; Bandinelli, Stefanie; März, Winfried; Isaacs, Aaron; van Dijk, Ko W; van Duijn, Cornelia M; Harris, Tamara B; Bouchard, Claude; Allison, Matthew A; Chasman, Daniel I; Ohlsson, Claes; Lind, Lars; Scott, Robert A; Langenberg, Claudia; Wareham, Nicholas J; Ferrucci, Luigi; Frayling, Timothy M; Pramstaller, Peter P; Borecki, Ingrid B; Waterworth, Dawn M; Bergmann, Sven; Waeber, Gérard; Vollenweider, Peter; Vestergaard, Henrik; Hansen, Torben; Pedersen, Oluf; Hu, Frank B; Eline Slagboom, P; Grallert, Harald; Spector, Tim D; Jukema, J W; Klein, Robert J; Schadt, Erik E; Franks, Paul W; Lindgren, Cecilia M; Leibel, Rudolph L; Loos, Ruth J F

    2016-01-01

    Leptin is an adipocyte-secreted hormone, the circulating levels of which correlate closely with overall adiposity. Although rare mutations in the leptin (LEP) gene are well known to cause leptin deficiency and severe obesity, no common loci regulating circulating leptin levels have been uncovered. Therefore, we performed a genome-wide association study (GWAS) of circulating leptin levels from 32,161 individuals and followed up loci reaching P<10(-6) in 19,979 additional individuals. We identify five loci robustly associated (P<5 × 10(-8)) with leptin levels in/near LEP, SLC32A1, GCKR, CCNL1 and FTO. Although the association of the FTO obesity locus with leptin levels is abolished by adjustment for BMI, associations of the four other loci are independent of adiposity. The GCKR locus was found associated with multiple metabolic traits in previous GWAS and the CCNL1 locus with birth weight. Knockdown experiments in mouse adipose tissue explants show convincing evidence for adipogenin, a regulator of adipocyte differentiation, as the novel causal gene in the SLC32A1 locus influencing leptin levels. Our findings provide novel insights into the regulation of leptin production by adipose tissue and open new avenues for examining the influence of variation in leptin levels on adiposity and metabolic health. PMID:26833098

  16. Genome-wide meta-analysis uncovers novel loci influencing circulating leptin levels

    PubMed Central

    Kilpeläinen, Tuomas O.; Carli, Jayne F. Martin; Skowronski, Alicja A.; Sun, Qi; Kriebel, Jennifer; Feitosa, Mary F; Hedman, Åsa K.; Drong, Alexander W.; Hayes, James E.; Zhao, Jinghua; Pers, Tune H.; Schick, Ursula; Grarup, Niels; Kutalik, Zoltán; Trompet, Stella; Mangino, Massimo; Kristiansson, Kati; Beekman, Marian; Lyytikäinen, Leo-Pekka; Eriksson, Joel; Henneman, Peter; Lahti, Jari; Tanaka, Toshiko; Luan, Jian'an; Greco M, Fabiola Del; Pasko, Dorota; Renström, Frida; Willems, Sara M.; Mahajan, Anubha; Rose, Lynda M.; Guo, Xiuqing; Liu, Yongmei; Kleber, Marcus E.; Pérusse, Louis; Gaunt, Tom; Ahluwalia, Tarunveer S.; Ju Sung, Yun; Ramos, Yolande F.; Amin, Najaf; Amuzu, Antoinette; Barroso, Inês; Bellis, Claire; Blangero, John; Buckley, Brendan M.; Böhringer, Stefan; I Chen, Yii-Der; de Craen, Anton J. N.; Crosslin, David R.; Dale, Caroline E.; Dastani, Zari; Day, Felix R.; Deelen, Joris; Delgado, Graciela E.; Demirkan, Ayse; Finucane, Francis M.; Ford, Ian; Garcia, Melissa E.; Gieger, Christian; Gustafsson, Stefan; Hallmans, Göran; Hankinson, Susan E.; Havulinna, Aki S; Herder, Christian; Hernandez, Dena; Hicks, Andrew A.; Hunter, David J.; Illig, Thomas; Ingelsson, Erik; Ioan-Facsinay, Andreea; Jansson, John-Olov; Jenny, Nancy S.; Jørgensen, Marit E.; Jørgensen, Torben; Karlsson, Magnus; Koenig, Wolfgang; Kraft, Peter; Kwekkeboom, Joanneke; Laatikainen, Tiina; Ladwig, Karl-Heinz; LeDuc, Charles A.; Lowe, Gordon; Lu, Yingchang; Marques-Vidal, Pedro; Meisinger, Christa; Menni, Cristina; Morris, Andrew P.; Myers, Richard H.; Männistö, Satu; Nalls, Mike A.; Paternoster, Lavinia; Peters, Annette; Pradhan, Aruna D.; Rankinen, Tuomo; Rasmussen-Torvik, Laura J.; Rathmann, Wolfgang; Rice, Treva K.; Brent Richards, J; Ridker, Paul M.; Sattar, Naveed; Savage, David B.; Söderberg, Stefan; Timpson, Nicholas J.; Vandenput, Liesbeth; van Heemst, Diana; Uh, Hae-Won; Vohl, Marie-Claude; Walker, Mark; Wichmann, Heinz-Erich; Widén, Elisabeth; Wood, Andrew R.; Yao, Jie; Zeller, Tanja; Zhang, Yiying; Meulenbelt, Ingrid; Kloppenburg, Margreet; Astrup, Arne; Sørensen, Thorkild I. A.; Sarzynski, Mark A.; Rao, D. C.; Jousilahti, Pekka; Vartiainen, Erkki; Hofman, Albert; Rivadeneira, Fernando; Uitterlinden, André G.; Kajantie, Eero; Osmond, Clive; Palotie, Aarno; Eriksson, Johan G.; Heliövaara, Markku; Knekt, Paul B.; Koskinen, Seppo; Jula, Antti; Perola, Markus; Huupponen, Risto K.; Viikari, Jorma S.; Kähönen, Mika; Lehtimäki, Terho; Raitakari, Olli T.; Mellström, Dan; Lorentzon, Mattias; Casas, Juan P.; Bandinelli, Stefanie; März, Winfried; Isaacs, Aaron; van Dijk, Ko W.; van Duijn, Cornelia M.; Harris, Tamara B.; Bouchard, Claude; Allison, Matthew A.; Chasman, Daniel I.; Ohlsson, Claes; Lind, Lars; Scott, Robert A.; Langenberg, Claudia; Wareham, Nicholas J.; Ferrucci, Luigi; Frayling, Timothy M.; Pramstaller, Peter P.; Borecki, Ingrid B.; Waterworth, Dawn M.; Bergmann, Sven; Waeber, Gérard; Vollenweider, Peter; Vestergaard, Henrik; Hansen, Torben; Pedersen, Oluf; Hu, Frank B.; Eline Slagboom, P; Grallert, Harald; Spector, Tim D.; Jukema, J.W.; Klein, Robert J.; Schadt, Erik E; Franks, Paul W.; Lindgren, Cecilia M.; Leibel, Rudolph L.; Loos, Ruth J. F.

    2016-01-01

    Leptin is an adipocyte-secreted hormone, the circulating levels of which correlate closely with overall adiposity. Although rare mutations in the leptin (LEP) gene are well known to cause leptin deficiency and severe obesity, no common loci regulating circulating leptin levels have been uncovered. Therefore, we performed a genome-wide association study (GWAS) of circulating leptin levels from 32,161 individuals and followed up loci reaching P<10−6 in 19,979 additional individuals. We identify five loci robustly associated (P<5 × 10−8) with leptin levels in/near LEP, SLC32A1, GCKR, CCNL1 and FTO. Although the association of the FTO obesity locus with leptin levels is abolished by adjustment for BMI, associations of the four other loci are independent of adiposity. The GCKR locus was found associated with multiple metabolic traits in previous GWAS and the CCNL1 locus with birth weight. Knockdown experiments in mouse adipose tissue explants show convincing evidence for adipogenin, a regulator of adipocyte differentiation, as the novel causal gene in the SLC32A1 locus influencing leptin levels. Our findings provide novel insights into the regulation of leptin production by adipose tissue and open new avenues for examining the influence of variation in leptin levels on adiposity and metabolic health. PMID:26833098

  17. A single early postnatal estradiol injection affects morphology and gene expression of the ovary and parametrial adipose tissue in adult female rats.

    PubMed

    Alexanderson, Camilla; Stener-Victorin, Elisabet; Kullberg, Joel; Nilsson, Staffan; Levin, Max; Cajander, Stefan; Lönn, Lars; Lönn, Malin; Holmäng, Agneta

    2010-10-01

    Events during early life can affect reproductive and metabolic functions in adulthood. We evaluated the programming effects of a single early postnatal estradiol injection (within 3h after birth) in female rats. We assessed ovarian and parametrial adipose tissue morphology, evaluated gene expression related to follicular development and adipose tissue metabolism, and developed a non-invasive volumetric estimation of parametrial adipose tissue by magnetic resonance imaging. Estradiol reduced ovarian weight, increased antral follicle size and number of atretic antral follicles, and decreased theca interna thickness in atretic antral follicles. Adult estradiol-injected rats also had malformed vaginal openings and lacked corpora lutea, confirming anovulation. Estradiol markedly reduced parametrial adipose tissue mass. Adipocyte size was unchanged, suggesting reduced adipocyte number. Parametrial adipose tissue lipoprotein lipase activity was increased. In ovaries, estradiol increased mRNA expression of adiponectin, complement component 3, estrogen receptor α, and glucose transporter 3 and 4; in parametrial adipose tissue, expression of complement component 3 was increased, expression of estrogen receptor α was decreased, and expression of leptin, lipoprotein lipase, and hormone-sensitive lipase was unaffected. These findings suggest that early postnatal estradiol exposure of female rats result in long-lasting effects on the ovary and parametrial adipose tissue at adult age. PMID:19857573

  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. 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

  20. Conjugated linoleic acid supplementation caused reduction of perilipin1 and aberrant lipolysis in epididymal adipose tissue

    SciTech Connect

    Cai, Demin; Li, Hongji; Zhou, Bo; Han, Liqiang; Zhang, Xiaomei; Yang, Guoyu; Yang, Guoqing

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer Conjugated linoleic acid supplementation suppresses perilipin1 in epididymal fat. Black-Right-Pointing-Pointer Conjugated linoleic acid inhibits promoter activity of perilipin1 in 3T3-L1 cells. Black-Right-Pointing-Pointer Conjugated linoleic acids elevate basal but blunt hormone-stimulated lipolysis. -- Abstract: Perilipin1, a coat protein of lipid droplet, plays a key role in adipocyte lipolysis and fat formation of adipose tissues. However, it is not clear how the expression of perilipin1 is affected in the decreased white adipose tissues (WAT) of mice treated with dietary supplement of conjugated linoleic acids (CLA). Here we obtained lipodystrophic mice by dietary administration of CLA which exhibited reduced epididymal (EPI) WAT, aberrant adipocytes and decreased expression of leptin in this tissue. We found both transcription and translation of perilipin1 was suppressed significantly in EPI WAT of CLA-treated mice compared to that of control mice. The gene expression of negative regulator tumor necrosis factor {alpha} (TNF{alpha}) and the positive regulator Peroxisome Proliferator-Activated Receptor-{gamma} (PPAR{gamma}) of perilipin1 was up-regulated and down-regulated, respectively. In cultured 3T3-L1 cells the promoter activity of perilipin1 was dramatically inhibited in the presence of CLA. Using ex vivo experiment we found that the basal lipolysis was elevated but the hormone-stimulated lipolysis blunted in adipose explants of CLA-treated mice compared to that of control mice, suggesting that the reduction of perilipin1 in white adipose tissues may at least in part contribute to CLA-mediated alternation of lipolysis of WAT.

  1. Expansion of Bone Marrow Adipose Tissue During Caloric Restriction Is Associated With Increased Circulating Glucocorticoids and Not With Hypoleptinemia.

    PubMed

    Cawthorn, William P; Scheller, Erica L; Parlee, Sebastian D; Pham, H An; Learman, Brian S; Redshaw, Catherine M H; Sulston, Richard J; Burr, Aaron A; Das, Arun K; Simon, Becky R; Mori, Hiroyuki; Bree, Adam J; Schell, Benjamin; Krishnan, Venkatesh; MacDougald, Ormond A

    2016-02-01

    Bone marrow adipose tissue (MAT) accounts for up to 70% of bone marrow volume in healthy adults and increases further in clinical conditions of altered skeletal or metabolic function. Perhaps most strikingly, and in stark contrast to white adipose tissue, MAT has been found to increase during caloric restriction (CR) in humans and many other species. Hypoleptinemia may drive MAT expansion during CR but this has not been demonstrated conclusively. Indeed, MAT formation and function are poorly understood; hence, the physiological and pathological roles of MAT remain elusive. We recently revealed that MAT contributes to hyperadiponectinemia and systemic adaptations to CR. To further these observations, we have now performed CR studies in rabbits to determine whether CR affects adiponectin production by MAT. Moderate or extensive CR decreased bone mass, white adipose tissue mass, and circulating leptin but, surprisingly, did not cause hyperadiponectinemia or MAT expansion. Although this unexpected finding limited our subsequent MAT characterization, it demonstrates that during CR, bone loss can occur independently of MAT expansion; increased MAT may be required for hyperadiponectinemia; and hypoleptinemia is not sufficient for MAT expansion. We further investigated this relationship in mice. In females, CR increased MAT without decreasing circulating leptin, suggesting that hypoleptinemia is also not necessary for MAT expansion. Finally, circulating glucocorticoids increased during CR in mice but not rabbits, suggesting that glucocorticoids might drive MAT expansion during CR. These observations provide insights into the causes and consequences of CR-associated MAT expansion, knowledge with potential relevance to health and disease. PMID:26696121

  2. 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

  3. 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

  4. 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

  5. Effect of Pioglitazone on the Fructose-Induced Abdominal Adipose Tissue Dysfunction

    PubMed Central

    Alzamendi, Ana; Giovambattista, Andrés; García, María E.; Rebolledo, Oscar R.; Gagliardino, Juan J.; Spinedi, Eduardo

    2012-01-01

    Aim. To test the potential role of PPARγ in the endocrine abdominal tissue dysfunction induced by feeding normal rats with a fructose rich diet (FRD) during three weeks. Methodology. Adult normal male rats received a standard commercial diet (CD) or FRD, (10% in drinking water) without or with pioglitazone (PIO) (i.p. 0.25 mg/Kg BW/day; CD-PIO and FRD-PIO). Thereafter, we measured circulating metabolic, endocrine, and oxidative stress (OS) markers, abdominal adipose tissue (AAT) mass, leptin (LEP) and plasminogen activator inhibitor-1 (PAI-1) tissue content/expression, and leptin release by isolated adipocytes incubated with different concentrations of insulin. Results. Plasma glucose, insulin, triglyceride, TBARS, LEP, and PAI-1 levels were higher in FRD rats; PIO coadministration fully prevented all these increments. AAT adipocytes from FRD rats were larger, secreted a higher amount of LEP, and displayed decreased sensitivity to insulin stimulation; these effects were significantly ameliorated by PIO. Whereas AAT LEP and PAI-1 (mRNA) concentrations increased significantly in FRD rats, those of insulin-receptor-substrate- (IRS-) 1 and IRS-2 were reduced. PIO coadministration prevented FRD effects on LEP, PAI-1, and IRS-2 (fully) and IRS-1 (partially) mRNAs in AAT. Conclusion. PPARγ would play a relevant role in the development of the FRD-induced metabolic-endocrine dysfunction. PMID:23091482

  6. 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

  7. 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

  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. 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

  11. Voluntary physical activity abolishes the proliferative tumor growth microenvironment created by adipose tissue in animals fed a high fat diet.

    PubMed

    Theriau, Christopher F; Shpilberg, Yaniv; Riddell, Michael C; Connor, Michael K

    2016-07-01

    The molecular mechanisms behind the obesity-breast cancer association may be regulated via adipokine secretion by white adipose tissue. Specifically, adiponectin and leptin are altered with adiposity and exert antagonistic effects on cancer cell proliferation. We set out to determine whether altering adiposity in vivo via high fat diet (HFD) feeding changed the tumor growth supporting nature of adipose tissue and whether voluntary physical activity (PA) could ameliorate these HFD-dependent effects. We show that conditioned media (CM) created from the adipose tissue of HFD fed animals caused an increase in the proliferation of MCF7 cells compared with cells exposed to CM prepared from the adipose of lean chow diet fed counterparts. This increased proliferation was driven within the MCF7 cells by an HFD-dependent antagonism between AMP-activated protein kinase (AMPK) and protein kinase B (Akt) signaling pathways, decreasing p27 protein levels via reduced phosphorylation at T198 and downregulation of adiponectin receptor 1 (AdipoR1). PA can ameliorate these proliferative effects of HFD-CM on MCF7 cells, increasing p27(T198) by AMPK, reducing pAkt(T308), and increasing AdipoR1, resulting in cell cycle withdrawal in a manner that depends on the PA intensity. High physical activity (>3 km/day) completely abolished the effects of HFD feeding. In addition, AdipoR1 overexpression mimics the effects of exercise, abolishing the proliferative effects of the HFD-CM on MCF7 cells and further enhancing the antiproliferative effects of PA on the HFD-CM. Thus voluntary PA represents a means to counteract the proliferative effects of adipose tissue on breast cancers in obese patients. PMID:27150834

  12. 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

  13. 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

  14. 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

  15. Dietary L-arginine supplementation differentially regulates expression of lipid-metabolic genes in porcine adipose tissue and skeletal muscle.

    PubMed

    Tan, Bie; Yin, Yulong; Liu, Zhiqiang; Tang, Wenjie; Xu, Haijun; Kong, Xiangfeng; Li, Xinguo; Yao, Kang; Gu, Wanting; Smith, Stephen B; Wu, Guoyao

    2011-05-01

    Obesity is a major health crisis worldwide and new treatments are needed to fight this epidemic. Using the swine model, we recently reported that dietary L-arginine (Arg) supplementation promotes muscle gain and reduces body-fat accretion. The present study tested the hypothesis that Arg regulates expression of key genes involved in lipid metabolism in skeletal muscle and white adipose tissue. Sixteen 110-day-old barrows were fed for 60 days a corn- and soybean-meal-based diet supplemented with 1.0% Arg or 2.05% L-alanine (isonitrogenous control). Blood samples, longissimus dorsi muscle and overlying subcutaneous adipose tissue were obtained from 170-day-old pigs for biochemical studies. Serum concentrations of leptin, alanine and glutamine were lower, but those for Arg and proline were higher in Arg-supplemented pigs than in control pigs. The percentage of oleic acid was higher but that of stearic acid and linoleic acid was lower in muscle of Arg-supplemented pigs, compared with control pigs. Dietary Arg supplementation increased mRNA levels for fatty acid synthase in muscle, while decreasing those for lipoprotein lipase, glucose transporter-4, and acetyl-coenzyme A carboxylase-α in adipose tissue. Additionally, mRNA levels for hormone sensitive lipase were higher in adipose tissue of Arg-supplemented pigs compared with control pigs. These results indicate that Arg differentially regulates expression of fat-metabolic genes in skeletal muscle and white adipose tissue, therefore favoring lipogenesis in muscle but lipolysis in adipose tissue. Our novel findings provide a biochemical basis for explaining the beneficial effect of Arg in improving the metabolic profile in mammals (including obese humans). PMID:20619625

  16. Brown Adipose Tissue Transplantation Reverses Obesity in Ob/Ob Mice.

    PubMed

    Liu, Xiaomeng; Wang, Siping; You, Yilin; Meng, Minghui; Zheng, Zongji; Dong, Meng; Lin, Jun; Zhao, Qianwei; Zhang, Chuanhai; Yuan, Xiaoxue; Hu, Tao; Liu, Lieqin; Huang, Yuanyuan; Zhang, Lei; Wang, Dehua; Zhan, Jicheng; Jong Lee, Hyuek; Speakman, John R; Jin, Wanzhu

    2015-07-01

    Increasing evidence indicates that brown adipose tissue (BAT) transplantation enhances whole-body energy metabolism in a mouse model of diet-induced obesity. However, it remains unclear whether BAT also has such beneficial effects on genetically obese mice. To address this issue, we transplanted BAT from C57/BL6 mice into the dorsal subcutaneous region of age- and sex-matched leptin deficient Ob/Ob mice. Interestingly, BAT transplantation led to a significant reduction of body weight gain with increased oxygen consumption and decreased total body fat mass, resulting in improvement of insulin resistance and liver steatosis. In addition, BAT transplantation increased the level of circulating adiponectin, whereas it reduced the levels of circulating free T3 and T4, which regulate thyroid hormone sensitivity in peripheral tissues. BAT transplantation also increased β3-adrenergic receptor and fatty acid oxidation related gene expression in subcutaneous and epididymal (EP) white adipose tissue. Accordingly, BAT transplantation increased whole-body thermogenesis. Taken together our results demonstrate that BAT transplantation may reduce obesity and its related diseases by activating endogenous BAT. PMID:25830704

  17. Chronic glucocorticoid exposure-induced epididymal adiposity is associated with mitochondrial dysfunction in white adipose tissue of male C57BL/6J mice.

    PubMed

    Yu, Jie; Yu, Bing; He, Jun; Zheng, Ping; Mao, Xiangbing; Han, Guoquan; Chen, Daiwen

    2014-01-01

    Prolonged and excessive glucocorticoids (GC) exposure resulted from Cushing's syndrome or GC therapy develops central obesity. Moreover, mitochondria are crucial in adipose energy homeostasis. Thus, we tested the hypothesis that mitochondrial dysfunction may contribute to chronic GC exposure-induced epididymal adiposity in the present study. A total of thirty-six 5-week-old male C57BL/6J mice (∼20 g) were administrated with 100 µg/ml corticosterone (CORT) or vehicle through drinking water for 4 weeks. Chronic CORT exposure mildly decreased body weight without altering food and water intake in mice. The epididymal fat accumulation was increased, but adipocyte size was decreased by CORT. CORT also increased plasma CORT, insulin, leptin, and fibroblast growth factor 21 concentrations as measured by RIA or ELISA. Interestingly, CORT increased plasma levels of triacylglycerols and nonesterified fatty acids, and up-regulated the expression of both lipolytic and lipogenic genes as determined by real-time RT-PCR. Furthermore, CORT impaired mitochondrial biogenesis and oxidative function in epididymal WAT. The reactive oxygen species production was increased and the activities of anti-oxidative enzymes were reduced by CORT treatment as well. Taken together, these findings reveal that chronic CORT administration-induced epididymal adiposity is, at least in part, associated with mitochondrial dysfunction in mouse epididymal white adipose tissue. PMID:25389775

  18. Analysis of gene networks in white adipose tissue development reveals a role for ETS2 in adipogenesis.

    PubMed

    Birsoy, Kivanç; Berry, Ryan; Wang, Tim; Ceyhan, Ozge; Tavazoie, Saeed; Friedman, Jeffrey M; Rodeheffer, Matthew S

    2011-11-01

    Obesity is characterized by an expansion of white adipose tissue mass that results from an increase in the size and the number of adipocytes. However, the mechanisms responsible for the formation of adipocytes during development and the molecular mechanisms regulating their increase and maintenance in adulthood are poorly understood. Here, we report the use of leptin-luciferase BAC transgenic mice to track white adipose tissue (WAT) development and guide the isolation and molecular characterization of adipocytes during development using DNA microarrays. These data reveal distinct transcriptional programs that are regulated during murine WAT development in vivo. By using a de novo cis-regulatory motif discovery tool (FIRE), we identify two early gene clusters whose promoters show significant enrichment for NRF2/ETS transcription factor binding sites. We further demonstrate that Ets transcription factors, but not Nrf2, are regulated during early adipogenesis and that Ets2 is essential for the normal progression of the adipocyte differentiation program in vitro. These data identify ETS2 as a functionally important transcription factor in adipogenesis and its possible role in regulating adipose tissue mass in adults can now be tested. Our approach also provides the basis for elucidating the function of other gene networks during WAT development in vivo. Finally these data confirm that although gene expression during adipogenesis in vitro recapitulates many of the patterns of gene expression in vivo, there are additional developmental transitions in pre and post-natal adipose tissue that are not evident in cell culture systems. PMID:21989915

  19. Rapamycin Normalizes Serum Leptin by Alleviating Obesity and Reducing Leptin Synthesis in Aged Rats.

    PubMed

    Scarpace, Philip J; Matheny, Michael; Strehler, Kevin Y E; Toklu, Hale Zerrin; Kirichenko, Nataliya; Carter, Christy S; Morgan, Drake; Tümer, Nihal

    2016-07-01

    This investigation examines whether a low intermittent dose of rapamycin will avoid the hyperlipidemia and diabetes-like syndrome associated with rapamycin while still decreasing body weight and adiposity in aged obese rats. Furthermore, we examined if the rapamycin-mediated decrease in serum leptin was a reflection of decreased adiposity, diminished leptin synthesis, or both. To these ends, rapamycin (1mg/kg) was administered three times a week to 3 and 24-month old rats. Body weight, food intake, body composition, mTORC1 signaling, markers of metabolism, as well as serum leptin levels and leptin synthesis in adipose tissue were examined and compared to that following a central infusion of rapamycin. Our data suggest that the dosing schedule of rapamycin acts on peripheral targets to inhibit mTORC1 signaling, preferentially reducing adiposity and sparing lean mass in an aged model of obesity resulting in favorable outcomes on blood triglycerides, increasing lean/fat ratio, and normalizing elevated serum leptin with age. The initial mechanism underlying the rapamycin responses appears to have a peripheral action and not central. The peripheral rapamycin responses may communicate an excessive nutrients signal to the hypothalamus that triggers an anorexic response to reduce food consumption. This coupled with potential peripheral mechanism serves to decrease adiposity and synthesis of leptin. PMID:25617379

  20. 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

  1. 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

  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. Plasma leptin in non-diabetic Asian Indians: association with abdominal adiposity.

    PubMed

    Ramachandran, A; Snehalatha, C; Vijay, V; Satyavani, K; Latha, E; Haffner, S M

    1997-11-01

    Plasma leptin concentrations were measured in 144 non-diabetic men and women (age 21-73 years, BMI 14.8-37.7 kg m(-2)), in fasting samples collected during a population survey for diabetes mellitus. Leptin, fasting and 2-h post-glucose load plasma concentrations of glucose and immunoreactive insulin were measured. In a subset of 50 normoglycaemic individuals, subcutaneous fat (SF) and visceral fat (VF) areas at L4-L5 level were also measured by CT. As in other populations, women had significantly higher plasma leptin concentrations than men (p < 0.001) but the values were similar in normal (NGT) and impaired glucose tolerance (IGT). Geometric mean concentrations of leptin in men and women with NGT were 4.8 and 17.7 ng ml(-1), respectively, and the corresponding values in IGT were 6.2 and 19.0 ng ml(-1). Multiple regression analysis in the total group showed that the leptin concentration (log-transformed) was strongly dependent on sex (R2 = 53.4%), BMI (R2 = 17.4%), and to a lesser degree on the 2-h plasma insulin (R2 = 2.4%) and the WHR (R2 = 0.8%). In men, the total abdominal fat showed a strong association with leptin (R2 = 49.3%) and in women the subcutaneous fat area showed a similar effect (R2 = 39.5%). It is likely that subcutaneous and not visceral fat may be a determinant of plasma leptin in Asian Indians, and the correlation between leptin and insulin resistance may be less strong than in other ethnic groups. PMID:9400917

  5. 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

  6. Soya protein ameliorates the metabolic abnormalities of dysfunctional adipose tissue of dyslipidaemic rats fed a sucrose-rich diet.

    PubMed

    Oliva, María E; Selenscig, Dante; D'Alessandro, María E; Chicco, Adriana; Lombardo, Yolanda B

    2011-04-01

    The present study investigates whether the replacement of dietary casein by soya protein isolate could be able to improve and/or even revert the morphological and metabolic abnormalities underlying the adipose tissue dysfunction of dyslipidaemic rats chronically fed (8 months) a sucrose-rich (62·5 %) diet (SRD). For this purpose, Wistar rats were fed a SRD for 4 months. From months 4 to 8, half the animals continued with the SRD and the other half were fed a SRD in which the source of protein, casein, was substituted by soya. The control group received a diet in which the source of carbohydrate was maize starch. Compared with the SRD-fed group, the results showed that: (1) soya protein decreased body-weight gain, limited the accretion of visceral adiposity and decreased adipose tissue cell volume without changes in total cell number; (2) soya protein increased the protein mass expression of PPARγ, which was significantly reduced in the fat pad of the SRD-fed rats; (3) the activity of the enzymes involved in the de novo lipogenesis of adipose tissue was significantly decreased/normalised; (4) soya protein corrected the inhibitory effect of SRD upon the anti-lipolytic action of insulin, reduced basal lipolysis and normalised the protein mass expression of GLUT-4. Dyslipidaemia, glucose homeostasis and plasma leptin levels returned to control values. The present study provides data showing the beneficial effects of soya protein to improve and/or revert the adipose tissue dysfunction of a dyslipidaemic insulin-resistant rat model and suggests that soya could maintain the functionality of the adipose tissue-liver axis improving/reverting lipotoxicity. PMID:21118606

  7. 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

  8. Implications of leptin in neuroendocrine regulation of male reproduction.

    PubMed

    Landry, David; Cloutier, Frank; Martin, Luc J

    2013-03-01

    Obesity is a major health problem contributing to increased subfertility in males, as well as increased morbidity for diseases related to a decline in testosterone production with aging. Leptin is a hormone produced by adipose tissue whose production increases with the amount of body fat. Several studies have supported a relationship between increased leptin production and regulation of reproductive function. Indeed, leptin acts at all levels of the hypothalamus-pituitary-gonadal (HPG) axis in males. However, most of the obese individuals become insensitive to increased endogenous leptin production and develop a functional leptin resistance. This deregulation of leptin signaling might result in abnormal endocrine and reproductive functions. Altered leptin dynamics may contribute to male infertility in different ways, leading to hypogonadism. These include leptin resistance or leptin insufficiency at the hypothalamus and leptin modulation of testicular physiology. In this review, we address the mechanisms of action of leptin at different levels of the HPG axis. Moreover, the influences of leptin on steroidogenesis and spermatogenesis, as well as seasonal variations of leptin's action on male reproduction are discussed. PMID:23522066

  9. 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

  10. Modulation of leptin resistance by food compounds.

    PubMed

    Aragonès, Gerard; Ardid-Ruiz, Andrea; Ibars, Maria; Suárez, Manuel; Bladé, Cinta

    2016-08-01

    Leptin is mainly secreted by white adipose tissue and regulates energy homeostasis by inhibiting food intake and stimulating energy expenditure through its action in neuronal circuits in the brain, particularly in the hypothalamus. However, hyperleptinemia coexists with the loss of responsiveness to leptin in common obese conditions. This phenomenon has been defined as leptin resistance and the restoration of leptin sensitivity is considered to be a useful strategy to treat obesity. This review summarizes the existing literature on potentially valuable nutrients and food components to reverse leptin resistance. Notably, several food compounds, such as teasaponins, resveratrol, celastrol, caffeine, and taurine among others, are able to restore the leptin signaling in neurons by overexpressing anorexigenic peptides (proopiomelanocortin) and/or repressing orexigenic peptides (neuropeptide Y/agouti-related peptide), thus decreasing food intake. Additionally, some nutrients, such as vitamins A and D, can improve leptin transport through the blood-brain barrier. Therefore, food components can improve leptin resistance by acting at different levels of the leptin pathway; moreover, some compounds are able to target more than one feature of leptin resistance. However, systematic studies are necessary to define the actual effectiveness of each compound. PMID:26842874

  11. Temperature-Acclimated Brown Adipose Tissue Modulates Insulin Sensitivity in Humans

    PubMed Central

    Lee, Paul; Smith, Sheila; Linderman, Joyce; Courville, Amber B.; Brychta, Robert J.; Dieckmann, William; Werner, Charlotte D.; Chen, Kong Y.

    2014-01-01

    In rodents, brown adipose tissue (BAT) regulates cold- and diet-induced thermogenesis (CIT; DIT). Whether BAT recruitment is reversible and how it impacts on energy metabolism have not been investigated in humans. We examined the effects of temperature acclimation on BAT, energy balance, and substrate metabolism in a prospective crossover study of 4-month duration, consisting of four consecutive blocks of 1-month overnight temperature acclimation (24°C [month 1] → 19°C [month 2] → 24°C [month 3] → 27°C [month 4]) of five healthy men in a temperature-controlled research facility. Sequential monthly acclimation modulated BAT reversibly, boosting and suppressing its abundance and activity in mild cold and warm conditions (P < 0.05), respectively, independent of seasonal fluctuations (P < 0.01). BAT acclimation did not alter CIT but was accompanied by DIT (P < 0.05) and postprandial insulin sensitivity enhancement (P < 0.05), evident only after cold acclimation. Circulating and adipose tissue, but not skeletal muscle, expression levels of leptin and adiponectin displayed reciprocal changes concordant with cold-acclimated insulin sensitization. These results suggest regulatory links between BAT thermal plasticity and glucose metabolism in humans, opening avenues to harnessing BAT for metabolic benefits. PMID:24954193

  12. 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

  13. 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

  14. Population variation and differences in serum leptin independent of adiposity: a comparison of Ache Amerindian men of Paraguay and lean American male distance runners

    PubMed Central

    Bribiescas, Richard G; Hickey, Matthew S

    2006-01-01

    Background Serum leptin variation is commonly associated with fat percentage (%), body mass index (BMI), and activity. In this investigation, we report population differences in mean leptin levels in healthy men as well as associations with fat % and BMI that are independent of these factors and reflect likely variation resulting from chronic environmental conditions. Methods Serum leptin levels, fat %, and BMI were compared between lean American distance runners and healthy Ache Native Americans of Paraguay. Mean levels were compared as were the regressions between fat %, BMI, and leptin. Comparisons were performed between male American distance runners (n = 13, mean age 32.2 ± 9.2 SD) and highly active male New World indigenous population (Ache of Paraguay, n = 20, mean age 32.8 ± 9.2) in order to determine whether significant population variation in leptin is evident in physically active populations living under different ecological circumstances independent of adiposity and BMI. Results While the Ache were hypothesized to exhibit higher leptin due to significantly greater adiposity (fat %, Ache 17.9 ± 1.8 SD; runners 9.7 ± 3.2, p < 0.0001), leptin levels were nonetheless significantly higher in American runners (Ache 1.13 ng/ml ± 0.38 SD; runners 2.19 ± 1.15; p < 0.007). Significant differences in the association between leptin and fat % was also evident between Ache and runner men. Although fat % was significantly related with leptin in runners (r = 0.90, p < 0.0001) fat % was negatively related in Ache men (r = -0.50, p < 0.03). Conclusion These results illustrate that chronic ecological conditions in addition to activity are likely factors that contribute to population variation in leptin levels and physiology. Population variation independent of adiposity should be considered to be an important source of variation, especially in light of ethnic and population differences in the incidence and etiology of obesity, diabetes, and other metabolic

  15. 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

  16. Subcutaneous adipose tissue plays a beneficial effect on subclinical atherosclerosis in young survivors of acute lymphocytic leukemia

    PubMed Central

    Siviero-Miachon, Adriana Aparecida; Spinola-Castro, Angela Maria; de Martino Lee, Maria Lucia; de Castro Monteiro, Carlos Manoel; de Camargo Carvalho, Antonio Carlos; Calixto, Antonio Ramos; Geloneze, Bruno; Guerra-Junior, Gil

    2015-01-01

    Purpose The aim of this study was to evaluate the relationship between body composition, metabolic profile, adipokines, and carotid intima-media thickness (cIMT) in young survivors of childhood acute lymphocytic leukemia (ALL). Patients and methods This cross-sectional study compared 55 ALL survivors, of chronological age between 15 years and 24 years, assigned into two groups according to the exposure to cranial radiation therapy (CRT; 25 irradiated and 30 nonirradiated) with 24 leukemia-free controls, and assessed body fat mass (dual-energy X-ray absorptiometry), computed tomography scan-derived abdominal adipose tissue, lipid profile, blood pressure (BP), adipokines, and cIMT by a multiple regression analysis. Results Treatment with CRT had an effect on all of the variables derived from the computed tomography scan: visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) (P<0.050). In a multiple linear regression model, cIMT positively correlated with exposure to CRT (P=0.029), diastolic BP (P=0.016), and leptin-to-adiponectin ratio (P=0.048), while negatively related to SAT (P=0.007). Conclusion In young survivors of childhood ALL, CRT modified the distribution of fat and played a critical role in determining cIMT. Leptin-to-adiponectin ratio, a biomarker of abdominal obesity and metabolic syndrome, and diastolic BP also influenced cIMT, a marker of subclinical atherosclerosis. Nonetheless, adiposity-associated vascular disease might be attenuated by SAT. Changes in body fat must be evaluated in this group of patients in the early course of survivorship in order to avoid premature cardiovascular disease associated with atherosclerosis. Yet, further research as regards the possible protective effect of SAT on vascular disease is warranted. PMID:26316772

  17. Neural innervation of white adipose tissue and the control of lipolysis.

    PubMed

    Bartness, Timothy J; Liu, Yang; Shrestha, Yogendra B; Ryu, Vitaly

    2014-10-01

    White adipose tissue (WAT) is innervated by the sympathetic nervous system (SNS) and its activation is necessary for lipolysis. WAT parasympathetic innervation is not supported. Fully-executed SNS-norepinephrine (NE)-mediated WAT lipolysis is dependent on β-adrenoceptor stimulation ultimately hinging on hormone sensitive lipase and perilipin A phosphorylation. WAT sympathetic drive is appropriately measured electrophysiologically and neurochemically (NE turnover) in non-human animals and this drive is fat pad-specific preventing generalizations among WAT depots and non-WAT organs. Leptin-triggered SNS-mediated lipolysis is weakly supported, whereas insulin or adenosine inhibition of SNS/NE-mediated lipolysis is strongly supported. In addition to lipolysis control, increases or decreases in WAT SNS drive/NE inhibit and stimulate white adipocyte proliferation, respectively. WAT sensory nerves are of spinal-origin and sensitive to local leptin and increases in sympathetic drive, the latter implicating lipolysis. Transsynaptic viral tract tracers revealed WAT central sympathetic and sensory circuits including SNS-sensory feedback loops that may control lipolysis. PMID:24736043

  18. Neural Innervation of White Adipose Tissue and the Control of Lipolysis

    PubMed Central

    Bartness, Timothy J.; Liu, Yang; Shrestha, Yogendra B.; Ryu, Vitaly

    2014-01-01

    White adipose tissue (WAT) is innervated by the sympathetic nervous system (SNS) and its activation is necessary for lipolysis. WAT parasympathetic innervation is not supported. Fully-executed SNS-norepinephrine (NE)-mediated WAT lipolysis is dependent on β-adrenoceptor stimulation ultimately hinging on hormone sensitive lipase and perilipin A phosphorylation. WAT sympathetic drive is appropriately measured by electrophysiological and neurochemical (NE turnover) in non-human animals and this drive is fat pad-specific preventing generalizations among WAT depots and non-WAT organs. Leptin-triggered SNS-mediated lipolysis is weakly supported, whereas insulin or adenosine inhibition of SNS/NE-mediated lipolysis is strongly supported. In addition to lipolysis control, increases or decreases in WAT SNS drive/NE inhibit and stimulate white adipocyte proliferation, respectively. WAT sensory nerves are of spinal-origin and sensitive to local leptin and increases in sympathetic drive, the latter implicating lipolysis. Transsynaptic viral tract tracer use revealed WAT central sympathetic and sensory circuits including SNS-sensory feedback loops that may control lipolysis. PMID:24736043

  19. 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

  20. 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

  1. Differential effects of cobalt and mercury on lipid metabolism in the white adipose tissue of high-fat diet-induced obesity mice

    SciTech Connect

    Kawakami, Takashige Hanao, Norihide; Nishiyama, Kaori; Kadota, Yoshito; Inoue, Masahisa; Sato, Masao; Suzuki, Shinya

    2012-01-01

    Metals and metalloid species are involved in homeostasis in energy systems such as glucose metabolism. Enlarged adipocytes are one of the most important causes of obesity-associated diseases. In this study, we studied the possibility that various metals, namely, CoCl{sub 2}, HgCl{sub 2}, NaAsO{sub 2} and MnCl{sub 2} pose risk to or have beneficial effects on white adipose tissue (WAT). Exposure to the four metals resulted in decreases in WAT weight and the size of enlarged adipocytes in mice fed a high-fat diet (HFD) without changes in liver weight, suggesting that the size and function of adipocytes are sensitive to metals. Repeated administration of CoCl{sub 2} significantly increased serum leptin, adiponectin and high-density lipoprotein (HDL) cholesterol levels and normalized glucose level and adipose cell size in mice fed HFD. In contrast, HgCl{sub 2} treatment significantly decreased serum leptin level with the down-regulation of leptin mRNA expression in WAT and a reduction in adipocyte size. Next, we tried to investigate possible factors that affect adipocyte size. Repeated exposure to HgCl{sub 2} significantly decreased the expression levels of factors upon the regulation of energy such as the PPARα and PPARγ mRNA expression levels in adipocytes, whereas CoCl{sub 2} had little effect on those genes expressions compared with that in the case of the mice fed HFD with a vehicle. In addition, repeated administration of CoCl{sub 2} enhanced AMPK activation in a dose-dependent manner in the liver, skeletal muscle and WAT; HgCl{sub 2} treatment also enhanced AMPK activation in the liver. Thus, both Co and Hg reduced WAT weight and the size of enlarged adipocytes, possibly mediated by AMKP activation in the mice fed HFD. However, inorganic cobalt may have a preventive role in obesity-related diseases through increased leptin, adiponectin and HDL-cholesterol levels, whereas inorganic mercury may accelerate the development of such diseases. These results may lead

  2. Marrow Adipose Tissue Expansion Coincides with Insulin Resistance in MAGP1-Deficient Mice.

    PubMed

    Walji, Tezin A; Turecamo, Sarah E; Sanchez, Alejandro Coca; Anthony, Bryan A; Abou-Ezzi, Grazia; Scheller, Erica L; Link, Daniel C; Mecham, Robert P; Craft, Clarissa S

    2016-01-01

    Marrow adipose tissue (MAT) is an endocrine organ with the potential to influence skeletal remodeling and hematopoiesis. Pathologic MAT expansion has been studied in the context of severe metabolic challenge, including caloric restriction, high fat diet feeding, and leptin deficiency. However, the rapid change in peripheral fat and glucose metabolism associated with these models impedes our ability to examine which metabolic parameters precede or coincide with MAT expansion. Microfibril-associated glycoprotein-1 (MAGP1) is a matricellular protein that influences cellular processes by tethering signaling molecules to extracellular matrix structures. MAGP1-deficient (Mfap2 (-/-)) mice display a progressive excess adiposity phenotype, which precedes insulin resistance and occurs without changes in caloric intake or ambulation. Mfap2 (-/-) mice were, therefore, used as a model to associate parameters of metabolic disease, bone remodeling, and hematopoiesis with MAT expansion. Marrow adiposity was normal in Mfap2 (-/-) mice until 6 months of age; however, by 10 months, marrow fat volume had increased fivefold relative to wild-type control at the same age. Increased gonadal fat pad mass and hyperglycemia were detectable in Mfap2 (-/-) mice by 2 months, but peaked by 6 months. The development of insulin resistance coincided with MAT expansion. Longitudinal characterization of bone mass demonstrated a disconnection in MAT volume and bone volume. Specifically, Mfap2 (-/-) mice had reduced trabecular bone volume by 2 months, but this phenotype did not progress with age or MAT expansion. Interestingly, MAT expansion in the 10-month-old Mfap2 (-/-) mice was associated with modest alterations in basal hematopoiesis, including a shift from granulopoiesis to B lymphopoiesis. Together, these findings indicate MAT expansion is coincident with insulin resistance, but not excess peripheral adiposity or hyperglycemia in Mfap2 (-/-) mice; and substantial MAT accumulation does

  3. 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...

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. Adipose tissue fatty acid metabolism during pregnancy in swine.

    PubMed

    McNamara, J P; Dehoff, M H; Collier, R J; Bazer, F W

    1985-08-01

    In vitro adipose tissue fatty acid pool size (POOL), fatty acid release (FAR) and esterification (EST) were measured in peritoneal (PFP) and subcutaneous mammary (MFP) fat pads of swine at d 15, 30, 45, 60, 75, 90, 105 and 112 of pregnancy. Plasma free fatty acids (FFA) and triglycerides (TG) were not altered by stage of pregnancy. Basal EST in PFP was generally constant across pregnancy with a peak at d 75. Basal EST in MFP was elevated at d 30, 75 and 112. Esterification in response to norepinephrine stimulus (NE) was lower than basal rates in both fat depots. Basal FAR was constant throughout pregnancy in PFP, but elevated at d 75 and 90 in MFP. Fatty acid release in response to NE was biphasic with peaks at d 30 and in late pregnancy (in MFP, micromolar FAR in response to NE was 69.3% greater on d 75 to 112 than on d 45 to 60). Basal POOL was constant throughout pregnancy in both depots and lower than NE-stimulated POOL. All responses to NE were greater in MFP than in PFP, indicating that adipose tissue surrounding the developing mammary gland had higher metabolic activity and a greater response to NE than peritoneal adipose. Changes in fatty acid metabolism during pregnancy in swine are temporally related to published values for plasma steroids, fetal growth and mammary development. Metabolic adaptations in adipose and mannary epithelial tissue occur in synchrony with changing plasma estrogen concentrations, redirecting energy flow from maternal adipose tissue toward developing mammary and fetal tissue. PMID:4044440