Curcumin Reduces Hepatic and White Adipose Tissue Inflammation and Expression of Specific Zinc Transporters in Diet-Induced Obese Mice

Abstract Objectives Obesity is a complex metabolic disease, that is often associated with non-alcoholic fatty liver disease (NAFLD). Inflammation is a common feature of both diseases. Curcumin, a traditionally used spice in Asia, exerts anti-inflammatory effects in liver and white adipose tissue (WAT) of diet-induced obese (DIO) mice. However, mechanisms involved in these beneficial effects remain obscure. Zinc is an important micronutrient involved in inflammatory responses. Whole-body zinc homeostasis plays a critical role in decreasing tissue specific inflammation. Zinc homeostasis is maintained mainly by zinc transporters known as ZnT (zinc transporters) and Zip (Zrt and Irt-like proteins) family. We propose that zinc transporters may contribute to curcumin's protective metabolic effects. Thus, the objective of this research was to determine curcumin's effects on inflammatory markers and zinc transporters in liver and WAT from DIO mice. Methods Male B6 mice were fed a HFD (45% kcal fat) or HFD supplemented with 0.4% (w/w) curcumin (HFC) for fourteen weeks. Serum triglycerides (TG) and free fatty acid (FFA) levels were measured. mRNA levels for inflammatory markers and zinc transporters were determined in WAT and liver by qRT-PCR. Results No significant changes were observed in body weight, serum TG and FFA levels with curcumin supplementation. However, gene expression of inflammatory markers, including Stat1, and Nf-KB subunit p65 were significantly reduced in liver and WAT from HFC group compared to HF (P < 0.05). Furthermore, curcumin reduced hepatic zinc transporters Zip10, Zip14, ZnT10 but increased ZnT9 expression. In WAT, curcumin significantly reduced mRNA levels for Zip1, Zip14, ZnT1, and ZnT7 (P < 0.05). Conclusions Our results indicate that zinc transporters may in part mediate the anti-inflammatory properties of curcumin, particularly Zip14, in WAT and liver of DIO mice. Future mechanistic studies are necessary to establish whether zinc transporters are required for curcumin's anti-inflammatory effects in obesity and associated NAFLD. Funding Sources AHA grant# 19AIREA34450279.

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Ursodeoxycholic Acid Regulates Hepatic Energy Homeostasis and White Adipose Tissue Macrophages Polarization in Leptin-Deficiency Obese Mice

Cells ◽

10.3390/cells8030253 ◽

2019 ◽

Vol 8 (3) ◽

pp. 253 ◽

Cited By ~ 9

Author(s):

Yu-Sheng Chen ◽

Hsuan-Miao Liu ◽

Tzung-Yan Lee

Keyword(s):

Adipose Tissue ◽

Mitochondrial Dysfunction ◽

Ursodeoxycholic Acid ◽

White Adipose Tissue ◽

Whole Body ◽

Bile Acid Metabolism ◽

Obese Mice ◽

Alcoholic Fatty Liver ◽

Tissue Macrophage ◽

Stat3 Phosphorylation

Obesity has been shown to play a role in the pathogenesis of several forms of metabolic syndrome, including non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes. Ursodeoxycholic acid (UDCA) has been shown to possess antioxidant and anti-inflammatory properties and prevents mitochondrial dysfunction in the progression of obesity-associated diseases. The aim of the study was to evaluate the mechanisms of UDCA during obesity-linked hepatic mitochondrial dysfunction and obesity-associated adipose tissue macrophage-induced inflammation in obese mice. UDCA significantly decreased lipid droplets, reduced free fatty acids (FFA) and triglycerides (TG), improved mitochondrial function, and enhanced white adipose tissue browning in ob/ob mice. This is associated with increased hepatic energy expenditure, mitochondria biogenesis, and incorporation of bile acid metabolism (Abca1, Abcg1 mRNA and BSEP, FGFR4, and TGR5 protein). In addition, UDCA downregulated NF-κB and STAT3 phosphorylation by negative regulation of the expression of SOCS1 and SOCS3 signaling. These changes were accompanied by decreased angiogenesis, as shown by the downregulation of VEGF, VCAM, and TGF-βRII expression. Importantly, UDCA is equally effective in reducing whole body adiposity. This is associated with decreased adipose tissue expression of macrophage infiltration (CD11b, CD163, and CD206) and lipogenic capacity markers (lipofuscin, SREBP-1, and CD36). Furthermore, UDCA significantly upregulated adipose browning in association with upregulation of SIRT-1-PGC1-α signaling in epididymis adipose tissue (EWAT). These results suggest that multi-targeted therapies modulate glucose and lipid biosynthesis fluxes, inflammatory response, angiogenesis, and macrophage differentiation. Therefore, it may be suggested that UDCA treatment may be a novel therapeutic agent for obesity.

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Mechanisms Mediating Dose-Dependent Effects of Eicosapentaenoic Acid in White Adipose Tissue From High Fat Diet-Induced Obese Mice

Current Developments in Nutrition ◽

10.1093/cdn/nzab055_019 ◽

2021 ◽

Vol 5 (Supplement_2) ◽

pp. 1209-1209

Author(s):

Hanna Davis ◽

Mandana Pahlavani ◽

Yujiao Zu ◽

Latha Ramalingam ◽

Shane Scoggin ◽

...

Keyword(s):

Adipose Tissue ◽

Eicosapentaenoic Acid ◽

White Adipose Tissue ◽

Macrophage Infiltration ◽

Low Grade ◽

Mrna Levels ◽

Obese Mice ◽

Adipocyte Size ◽

M1 Macrophage ◽

Anti Inflammatory

Abstract Objectives Obesity is a global epidemic and complex disease associated with an expansion of white adipose tissue (WAT). Obesity is accompanied by chronic low-grade inflammation, characterized by elevated levels of secreted pro-inflammatory cytokines and M1 macrophage infiltration into WAT. Eicosapentaenoic acid (EPA), a long-chain omega-3 polyunsaturated fatty acid, has been reported to have anti-obesity and anti-inflammatory properties. Moreover, we previously showed that EPA dose-dependently improved glucose intolerance, and inflammation in diet-induced obese mice. The objective of this study is to further determine mechanisms underlying these metabolic protective effects of EPA in epididymal WAT (e-WAT). Methods Male B6 mice were fed a HF diet (45% kcal fat) or a HF diet supplemented with 9, 18, or 36 g/kg of EPA-enriched fish oil (EPA 9, 18 or 36) for 14 weeks. We performed histological assessments in eWAT to determine adipocyte size; and measure macrophage infiltration by immunohistochemistry using galectin-3. RNA was isolated from eWAT for RNA sequencing and gene expression analyses. Data were analyzed using GraphPad Prism software. Results EPA36-fed mice had significantly lower body weight and fat percentage, compared to HF (P < 0.05). In addition, EPA18 and 36 significantly decreased weight of e-WAT (P < 0.05) and increased glucose clearance compared to HF (P < 0.05). Moreover, all EPA doses had smaller adipocytes (P < 0.05). Compared to HF, EPA18 and 36 significantly reduced macrophage infiltration in e-7.43 fold, respectively. Consistent with these changes, EPA18 and 36 reduced the mRNA levels of HF-induced inflammatory markers, including arachidonate 5-lipoxygenase (Alox5) and leukotriene B4 receptor (Ltb4r) compared to HF (P < 0.05). RNA Seq analyses revealed that EPA18 attenuated HF-induced inflammation in part by up-regulating cyclic AMP (cAMP)-dependent protein kinase A (PKA) signaling pathways and down-regulating triggering receptor expressed on myeloid cells 1 (TREM1) signaling. Conclusions EPA dose-dependently ameliorated HF-induced obesity and inflammation by reducing adipocyte size and macrophage infiltration and modulating pro- and anti-inflammatory pathways in e-WAT. These effects were achieved at human equivalent doses, that are currently prescribed for reducing triglycerides. Funding Sources USDA NIFA NIH.

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A214 BARIATRIC SURGERY PATIENTS WITH NON-ALCOHOLIC FATTY LIVER DISEASE HAVE DIFFERENT VISCERAL ADIPOSE TISSUE GENE EXPRESSION COMPARED TO THOSE WITH NORMAL LIVER

Journal of the Canadian Association of Gastroenterology ◽

10.1093/jcag/gwab002.212 ◽

2021 ◽

Vol 4 (Supplement_1) ◽

pp. 245-247

Author(s):

S Keshavjee ◽

J Yadav ◽

K Schwenger ◽

S Fischer ◽

T D Jackson ◽

...

Keyword(s):

Gene Expression ◽

Bariatric Surgery ◽

Adipose Tissue ◽

Visceral Adipose Tissue ◽

Inflammatory Markers ◽

Fatty Liver Disease ◽

Alcoholic Fatty Liver ◽

Visceral Adipose ◽

Healthy Liver ◽

Alcoholic Fatty Liver Disease

Abstract Background Non-alcoholic fatty liver disease (NAFLD) includes simple steatosis (SS) and nonalcoholic steatohepatitis (NASH). It affects 74–98% of individuals with morbid obesity undergoing bariatric surgery (BSX). Among several factors contributing to NAFLD pathogenesis, adipokines secreted by visceral adipose tissue (VAT) can play a role by regulating glucose/lipid metabolism and inflammation. Aims This study aims to determine if visceral adipose tissue adipokine and cytokine gene expression are associated with NAFLD (SS and NASH) at the time of BSX. Methods Patients were recruited from the Toronto Western Hospital Bariatric Clinic. Demographic data was recorded. The VAT and liver biopsies were collected at the time of bariatric surgery. VAT adipokines and other mediators were assessed by RT-PCR and included markers of thermogenic capacity, inflammation, fibrosis, adipokines, and others. Liver histology was assessed by a pathologist using the Brunt system and individuals were diagnosed as either SS, NASH, or having a healthy liver (HL). Blood samples were collected pre-BSX to measure liver and metabolic syndrome related parameters, including HOMA-IR, HbA1c, liver enzymes, and lipid profile. Anthropometry was also assessed. Groups were compared using Kruskal-Wallis test followed by Wilcoxon ranked sum, or chi-square and Fisher’s exact test as necessary. Data was considered to be statistically significant with a p-value less than 0.05. Results We are presenting data on 126 patients, 80.2% females with a median age of 49 and a body mass index (BMI) of 46.9. Fifty-seven patients had SS, 34 had NASH and 35 had a healthy liver (HL). BMI, age, and sex did not differ between the three groups. First, we found that those with NASH had significantly higher VAT expression of fibrosis (Loxl2), inflammation (CCL4 and TGFb1) and proliferation markers (E2F1) and significantly lower expression of adipokines (TNFa and resistin) compared to HL. Also, we found that SS had significantly higher fibrosis (Col3a1, Col6a1, Loxl2, CD9 and Acta2), inflammation (Nox2, TGFb1, IFNg and Clec10a), browning (PPARa, PPARg and Glut1) and proliferation (E2F1) marker expression compared to HL. Conclusions Results show that there is a significant difference in the expression pattern of VAT fibrotic and inflammatory markers between HL, SS and NASH patients. The observed increase of inflammatory markers in NAFLD is in line with prior research outlining the ability of inflammatory mediators from VAT to contribute to liver pathology via portal circulation. The relationship between VAT characteristics and NAFLD are important in understanding the widespread metabolic effects of obesity. Funding Agencies CIHRCanadian Liver foundation

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Interactive effects of aging and aerobic capacity on energy metabolism–related metabolites of serum, skeletal muscle, and white adipose tissue

GeroScience ◽

10.1007/s11357-021-00387-1 ◽

2021 ◽

Author(s):

Haihui Zhuang ◽

Sira Karvinen ◽

Timo Törmäkangas ◽

Xiaobo Zhang ◽

Xiaowei Ojanen ◽

...

Keyword(s):

Adipose Tissue ◽

Amino Acid ◽

White Adipose Tissue ◽

Aerobic Capacity ◽

Amino Acid Metabolism ◽

Acid Metabolism ◽

Disease Risk ◽

Whole Body ◽

Whole Body Metabolism

AbstractAerobic capacity is a strong predictor of longevity. With aging, aerobic capacity decreases concomitantly with changes in whole body metabolism leading to increased disease risk. To address the role of aerobic capacity, aging, and their interaction on metabolism, we utilized rat models selectively bred for low and high intrinsic aerobic capacity (LCRs/HCRs) and compared the metabolomics of serum, muscle, and white adipose tissue (WAT) at two time points: Young rats were sacrificed at 9 months of age, and old rats were sacrificed at 21 months of age. Targeted and semi-quantitative metabolomics analysis was performed on the ultra-pressure liquid chromatography tandem mass spectrometry (UPLC-MS) platform. The effects of aerobic capacity, aging, and their interaction were studied via regression analysis. Our results showed that high aerobic capacity is associated with an accumulation of isovalerylcarnitine in muscle and serum at rest, which is likely due to more efficient leucine catabolism in muscle. With aging, several amino acids were downregulated in muscle, indicating more efficient amino acid metabolism, whereas in WAT less efficient amino acid metabolism and decreased mitochondrial β-oxidation were observed. Our results further revealed that high aerobic capacity and aging interactively affect lipid metabolism in muscle and WAT, possibly combating unfavorable aging-related changes in whole body metabolism. Our results highlight the significant role of WAT metabolism for healthy aging.

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Maternal obesity during pregnancy leads to adipose tissue ER stress in mice via miR-126-mediated reduction in Lunapark

Diabetologia ◽

10.1007/s00125-020-05357-4 ◽

2021 ◽

Author(s):

Juliana de Almeida-Faria ◽

Daniella E. Duque-Guimarães ◽

Thomas P. Ong ◽

Lucas C. Pantaleão ◽

Asha A. Carpenter ◽

...

Keyword(s):

Adipose Tissue ◽

Glucose Tolerance ◽

Er Stress ◽

Maternal Obesity ◽

Luciferase Assay ◽

Whole Body ◽

Mrna Levels ◽

Protein Levels ◽

Novel Targets

Abstract Aims/hypothesis Levels of the microRNA (miRNA) miR-126-3p are programmed cell-autonomously in visceral adipose tissue of adult offspring born to obese female C57BL/6J mice. The spectrum of miR-126-3p targets and thus the consequences of its dysregulation for adipocyte metabolism are unknown. Therefore, the aim of the current study was to identify novel targets of miR-126-3p in vitro and then establish the outcomes of their dysregulation on adipocyte metabolism in vivo using a well-established maternal obesity mouse model. Methods miR-126-3p overexpression in 3T3-L1 pre-adipocytes followed by pulsed stable isotope labelling by amino acids in culture (pSILAC) was performed to identify novel targets of the miRNA. Well-established bioinformatics algorithms and luciferase assays were then employed to confirm those that were direct targets of miR-126-3p. Selected knockdown experiments were performed in vitro to define the consequences of target dysregulation. Quantitative real-time PCR, immunoblotting, histology, euglycaemic–hyperinsulinaemic clamps and glucose tolerance tests were performed to determine the phenotypic and functional outcomes of maternal programmed miR-126-3p levels in offspring adipose tissue. Results The proteomic approach confirmed the identity of known targets of miR-126-3p (including IRS-1) and identified Lunapark, an endoplasmic reticulum (ER) protein, as a novel one. We confirmed by luciferase assay that Lunapark was a direct target of miR-126-3p. Overexpression of miR-126-3p in vitro led to a reduction in Lunapark protein levels and increased Perk (also known as Eif2ak3) mRNA levels and small interference-RNA mediated knockdown of Lunapark led to increased Xbp1, spliced Xbp1, Chop (also known as Ddit3) and Perk mRNA levels and an ER stress transcriptional response in 3T3-L1 pre-adipocytes. Consistent with the results found in vitro, increased miR-126-3p expression in adipose tissue from adult mouse offspring born to obese dams was accompanied by decreased Lunapark and IRS-1 protein levels and increased markers of ER stress. At the whole-body level the animals displayed glucose intolerance. Conclusions/interpretation Concurrently targeting IRS-1 and Lunapark, a nutritionally programmed increase in miR-126-3p causes adipose tissue insulin resistance and an ER stress response, both of which may contribute to impaired glucose tolerance. These findings provide a novel mechanism by which obesity during pregnancy leads to increased risk of type 2 diabetes in the offspring and therefore identify miR-126-3p as a potential therapeutic target. Graphical abstract

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Metallothionein gene expression and secretion in white adipose tissue

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.2000.279.6.r2329 ◽

2000 ◽

Vol 279 (6) ◽

pp. R2329-R2335 ◽

Cited By ~ 24

Author(s):

Paul Trayhurn ◽

Jacqueline S. Duncan ◽

Anne M. Wood ◽

John H. Beattie

Keyword(s):

Gene Expression ◽

Molecular Weight ◽

Adipose Tissue ◽

White Adipose Tissue ◽

Stromal Vascular Fraction ◽

Low Molecular Weight ◽

Secretory Product ◽

Mrna Levels ◽

Gene Encoding ◽

Adrenoceptor Agonist

White adipose tissue (WAT) has been examined to determine whether the gene encoding metallothionein (MT), a low-molecular-weight stress response protein, is expressed in the tissue and whether MT may be a secretory product of adipocytes. The MT-1 gene was expressed in epididymal WAT, with MT-1 mRNA levels being similar in lean and obese ( ob/ ob) mice. MT-1 mRNA was found in each of the main adipose tissue sites (epididymal, perirenal, omental, subcutaneous), and there was no major difference between depots. Separation of adipocytes from the stromal-vascular fraction of WAT indicated that the MT gene (MT-1 and MT-2) was expressed in adipocytes themselves. Treatment of mice with zinc had no effect on MT-1 mRNA levels in WAT, despite strong induction of MT-1 expression in the liver. MT-1 gene expression in WAT was also unaltered by fasting or norepinephrine. However, administration of a β3-adrenoceptor agonist, BRL-35153A, led to a significant increase in MT-1 mRNA. On differentiation of fibroblastic preadipocytes to adipocytes in primary culture, MT was detected in the medium, suggesting that the protein may be secreted from WAT. It is concluded that WAT may be a significant site of MT production; within adipocytes, MT could play an antioxidant role in protecting fatty acids from damage.

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Metabolic Effects of Acute Hyperketonaemia in Man before and during An Hyperinsulinaemic Euglycaemic Clamp

Clinical Science ◽

10.1042/cs0860677 ◽

1994 ◽

Vol 86 (6) ◽

pp. 677-687 ◽

Cited By ~ 14

Author(s):

J. Webber ◽

E. Simpson ◽

H. Parkin ◽

I. A. MacDonald

Keyword(s):

Adipose Tissue ◽

Glucose Uptake ◽

Glucose Oxidation ◽

Respiratory Exchange Ratio ◽

Saline Infusion ◽

Metabolic Effects ◽

Whole Body ◽

Glucose Storage ◽

Adipose Tissue Lipolysis ◽

Subcutaneous Abdominal Adipose Tissue

1. The effects of acutely raising blood ketone body levels to those seen after 72 h of starvation were examined in 10 subjects after an overnight fast. Metabolic rate and respiratory exchange ratio were measured with indirect calorimetry before and during an insulin—glucose clamp. Arteriovenous differences were measured across forearm and subcutaneous abdominal adipose tissue. 2. In response to the clamp the respiratory exchange ratio rose from 0.82 to 0.83 during 3-hydroxybutyrate infusion and from 0.83 to 0.94 during control (saline) infusion (P < 0.001). 3. Forearm glucose uptake at the end of the clamp was 4.02 ± 0.95 (3-hydroxybutyrate infusion) and 7.09 ± 1.24 mmol min−1 100 ml−1 forearm (saline infusion). Whole body glucose uptake at the end of the clamp was 72.8 ± 7.9 (3-hydroxybutyrate infusion) and 51.0 ± 3.0 (saline infusion) mmol min−1 kg−1 body weight−1. 4. 3-Hydroxybutyrate infusion reduced the baseline abdominal venous—arterialized venous glycerol difference from 84 ± 28 to 25 ± 12 mmol/l and the non-esterified fatty acid difference from 0.60 ± 0.17 to 0.02 ± 0.09 mmol/l (P < 0.05 versus saline infusion). 5. Hyperketonaemia reduces adipose tissue lipolysis and decreases insulin-mediated forearm glucose uptake. Hyperketonaemia appears to prevent insulin-stimulated glucose oxidation, but does not reduce insulin-mediated glucose storage.

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Central Leptin Regulates Total Ceramide Content and Sterol Regulatory Element Binding Protein-1C Proteolytic Maturation in Rat White Adipose Tissue

Endocrinology ◽

10.1210/en.2008-0505 ◽

2008 ◽

Vol 150 (1) ◽

pp. 169-178 ◽

Cited By ~ 36

Author(s):

Elena Bonzón-Kulichenko ◽

Dominik Schwudke ◽

Nilda Gallardo ◽

Eduardo Moltó ◽

Teresa Fernández-Agulló ◽

...

Keyword(s):

Nervous System ◽

Adipose Tissue ◽

Insulin Sensitivity ◽

White Adipose Tissue ◽

Binding Protein ◽

Regulatory Element ◽

Mrna Levels ◽

Element Binding Protein ◽

Ceramide Content ◽

Sterol Regulatory Element

Obesity and type 2 diabetes are associated with insulin and leptin resistance, and increased ceramide contents in target tissues. Because the adipose tissue has become a central focus in these diseases, and leptin-induced increases in insulin sensitivity may be related to effects of leptin on lipid metabolism, we investigated herein whether central leptin was able to regulate total ceramide levels and the expression of enzymes involved in ceramide metabolism in rat white adipose tissue (WAT). After 7 d central leptin treatment, the total content of ceramides was analyzed by quantitative shotgun lipidomics mass spectrometry. The effects of leptin on the expression of several enzymes of the sphingolipid metabolism, sterol regulatory element binding protein (SREBP)-1c, and insulin-induced gene 1 (INSIG-1) in this tissue were studied. Total ceramide levels were also determined after surgical WAT denervation. Central leptin infusion significantly decreased both total ceramide content and the long-chain fatty acid ceramide species in WAT. Concomitant with these results, leptin decreased the mRNA levels of enzymes involved in de novo ceramide synthesis (SPT-1, LASS2, LASS4) and ceramide production from sphingomyelin (SMPD-1/2). The mRNA levels of enzymes of ceramide degradation (Asah1/2) and utilization (sphingomyelin synthase, ceramide kinase, glycosyl-ceramide synthase, GM3 synthase) were also down-regulated. Ceramide-lowering effects of central leptin were prevented by local autonomic nervous system denervation of WAT. Finally, central leptin treatment markedly increased INSIG-1 mRNA expression and impaired SREBP-1c activation in epididymal WAT. These observations indicate that in vivo central leptin, acting through the autonomic nervous system, regulates total ceramide levels and SREBP-1c proteolytic maturation in WAT, probably contributing to improve the overall insulin sensitivity. Central leptin decreases total ceramide levels and prevents sterol regulatory element binding protein (SREBP-1C) proteolytic maturation in white adipose tissue, and probably, in this way, contributes to improve the overall insulin sensitivity.

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Metabolic Effects of Oral Phenelzine Treatment on High-Sucrose-Drinking Mice

International Journal of Molecular Sciences ◽

10.3390/ijms19102904 ◽

2018 ◽

Vol 19 (10) ◽

pp. 2904 ◽

Cited By ~ 5

Author(s):

Christian Carpéné ◽

Saioa Gómez-Zorita ◽

Alice Chaplin ◽

Josep Mercader

Keyword(s):

Adipose Tissue ◽

Phosphoenolpyruvate Carboxykinase ◽

De Novo ◽

Uncoupling Protein ◽

De Novo Lipogenesis ◽

Metabolic Effects ◽

Mrna Levels ◽

Brown Adipose ◽

High Sucrose ◽

Sucrose Drinking

Phenelzine has been suggested to have an antiobesity effect by inhibiting de novo lipogenesis, which led us to investigate the metabolic effects of oral chronic phenelzine treatment in high-sucrose-drinking mice. Sucrose-drinking mice presented higher body weight gain and adiposity versus controls. Phenelzine addition did not decrease such parameters, even though fat pad lipid content and weights were not different from controls. In visceral adipocytes, phenelzine did not impair insulin-stimulated de novo lipogenesis and had no effect on lipolysis. However, phenelzine reduced the mRNA levels of glucose transporters 1 and 4 and phosphoenolpyruvate carboxykinase in inguinal white adipose tissue (iWAT), and altered circulating levels of free fatty acids (FFA) and glycerol. Interestingly, glycemia was restored in phenelzine-treated mice, which also had higher insulinaemia. Phenelzine-treated mice presented higher rectal temperature, which was associated to reduced mRNA levels of uncoupling protein 1 in brown adipose tissue. Furthermore, unlike sucrose-drinking mice, hepatic malondialdehyde levels were not altered. In conclusion, although de novo lipogenesis was not inhibited by phenelzine, the data suggest that the ability to re-esterify FFA is impaired in iWAT. Moreover, the effects on glucose homeostasis and oxidative stress suggest that phenelzine could alleviate obesity-related alterations and deserves further investigation in obesity models.

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Regulation of angiopoietin-like protein 4/fasting-induced adipose factor (Angptl4/FIAF) expression in mouse white adipose tissue and 3T3-L1 adipocytes

British Journal Of Nutrition ◽

10.1017/s0007114507882961 ◽

2008 ◽

Vol 100 (1) ◽

pp. 18-26 ◽

Cited By ~ 35

Author(s):

Sarah Dutton ◽

Paul Trayhurn

Keyword(s):

Skeletal Muscle ◽

Cell Culture ◽

Adipose Tissue ◽

White Adipose Tissue ◽

Culture Medium ◽

Mrna Level ◽

Mrna Levels ◽

Rt Pcr ◽

Before And After ◽

Stimulation Of

Angiopoietin-like protein 4 (Angptl4)/FIAF (fasting-induced adipose factor) was first identified as a target for PPAR and to be strongly induced in white adipose tissue (WAT) by fasting. Here we have examined the regulation of the expression and release of this adipokine in mouse WAT and in 3T3-L1 adipocytes. Angptl4/FIAF expression was measured by RT-PCR and real-time PCR; plasma Angptl4/FIAF and release of the protein in cell culture was determined by western blotting. The Angptl4/FIAF gene was expressed in each of the major WAT depots of mice, the mRNA level in WAT being similar to the liver and much higher (>50-fold) than skeletal muscle. Fasting mice (18 h) resulted in a substantial increase in Angptl4/FIAF mRNA in liver and muscle (9·5- and 21-fold, respectively); however, there was no effect of fasting on Angptl4/FIAF mRNA in WAT and the plasma level of Angptl4/FIAF was unchanged. The Angptl4/FIAF gene was expressed in 3T3-L1 adipocytes before and after differentiation, the level increasing post-differentiation; Angptl4/FIAF was released into the culture medium. Insulin, leptin, dexamethasone, noradrenaline, TNFα and several IL (IL-1β, IL-6, IL-10, IL-18) had little effect on Angptl4/FIAF mRNA levels in 3T3-L1 adipocytes. However, a major stimulation of Angptl4/FIAF expression was observed with rosiglitazone and the inflammatory prostaglandins PGD2 and PGJ2. Angptl4/FIAF does not act as an adipose tissue signal of nutritional status, but is markedly induced by fasting in liver and skeletal muscle.

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