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Kochumon S, Malik MZ, Sindhu S, Arefanian H, Jacob T, Bahman F, Nizam R, Hasan A, Thomas R, Al-Rashed F, Shenouda S, Wilson A, Albeloushi S, Almansour N, Alhamar G, Al Madhoun A, Alzaid F, Thanaraj TA, Koistinen HA, Tuomilehto J, Al-Mulla F, Ahmad R. Gut Dysbiosis Shaped by Cocoa Butter-Based Sucrose-Free HFD Leads to Steatohepatitis, and Insulin Resistance in Mice. Nutrients 2024; 16:1929. [PMID: 38931284 PMCID: PMC11207001 DOI: 10.3390/nu16121929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 06/05/2024] [Accepted: 06/07/2024] [Indexed: 06/28/2024] Open
Abstract
BACKGROUND High-fat diets cause gut dysbiosis and promote triglyceride accumulation, obesity, gut permeability changes, inflammation, and insulin resistance. Both cocoa butter and fish oil are considered to be a part of healthy diets. However, their differential effects on gut microbiome perturbations in mice fed high concentrations of these fats, in the absence of sucrose, remains to be elucidated. The aim of the study was to test whether the sucrose-free cocoa butter-based high-fat diet (C-HFD) feeding in mice leads to gut dysbiosis that associates with a pathologic phenotype marked by hepatic steatosis, low-grade inflammation, perturbed glucose homeostasis, and insulin resistance, compared with control mice fed the fish oil based high-fat diet (F-HFD). RESULTS C57BL/6 mice (5-6 mice/group) were fed two types of high fat diets (C-HFD and F-HFD) for 24 weeks. No significant difference was found in the liver weight or total body weight between the two groups. The 16S rRNA sequencing of gut bacterial samples displayed gut dysbiosis in C-HFD group, with differentially-altered microbial diversity or relative abundances. Bacteroidetes, Firmicutes, and Proteobacteria were highly abundant in C-HFD group, while the Verrucomicrobia, Saccharibacteria (TM7), Actinobacteria, and Tenericutes were more abundant in F-HFD group. Other taxa in C-HFD group included the Bacteroides, Odoribacter, Sutterella, Firmicutes bacterium (AF12), Anaeroplasma, Roseburia, and Parabacteroides distasonis. An increased Firmicutes/Bacteroidetes (F/B) ratio in C-HFD group, compared with F-HFD group, indicated the gut dysbiosis. These gut bacterial changes in C-HFD group had predicted associations with fatty liver disease and with lipogenic, inflammatory, glucose metabolic, and insulin signaling pathways. Consistent with its microbiome shift, the C-HFD group showed hepatic inflammation and steatosis, high fasting blood glucose, insulin resistance, increased hepatic de novo lipogenesis (Acetyl CoA carboxylases 1 (Acaca), Fatty acid synthase (Fasn), Stearoyl-CoA desaturase-1 (Scd1), Elongation of long-chain fatty acids family member 6 (Elovl6), Peroxisome proliferator-activated receptor-gamma (Pparg) and cholesterol synthesis (β-(hydroxy β-methylglutaryl-CoA reductase (Hmgcr). Non-significant differences were observed regarding fatty acid uptake (Cluster of differentiation 36 (CD36), Fatty acid binding protein-1 (Fabp1) and efflux (ATP-binding cassette G1 (Abcg1), Microsomal TG transfer protein (Mttp) in C-HFD group, compared with F-HFD group. The C-HFD group also displayed increased gene expression of inflammatory markers including Tumor necrosis factor alpha (Tnfa), C-C motif chemokine ligand 2 (Ccl2), and Interleukin-12 (Il12), as well as a tendency for liver fibrosis. CONCLUSION These findings suggest that the sucrose-free C-HFD feeding in mice induces gut dysbiosis which associates with liver inflammation, steatosis, glucose intolerance and insulin resistance.
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Affiliation(s)
- Shihab Kochumon
- Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (M.Z.M.); (S.S.); (H.A.); (T.J.); (F.B.); (R.N.); (A.H.); (R.T.); (F.A.-R.); (S.S.); (A.W.); (S.A.); (N.A.); (G.A.); (A.A.M.); (F.A.); (T.A.T.); (F.A.-M.)
| | - Md. Zubbair Malik
- Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (M.Z.M.); (S.S.); (H.A.); (T.J.); (F.B.); (R.N.); (A.H.); (R.T.); (F.A.-R.); (S.S.); (A.W.); (S.A.); (N.A.); (G.A.); (A.A.M.); (F.A.); (T.A.T.); (F.A.-M.)
| | - Sardar Sindhu
- Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (M.Z.M.); (S.S.); (H.A.); (T.J.); (F.B.); (R.N.); (A.H.); (R.T.); (F.A.-R.); (S.S.); (A.W.); (S.A.); (N.A.); (G.A.); (A.A.M.); (F.A.); (T.A.T.); (F.A.-M.)
| | - Hossein Arefanian
- Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (M.Z.M.); (S.S.); (H.A.); (T.J.); (F.B.); (R.N.); (A.H.); (R.T.); (F.A.-R.); (S.S.); (A.W.); (S.A.); (N.A.); (G.A.); (A.A.M.); (F.A.); (T.A.T.); (F.A.-M.)
| | - Texy Jacob
- Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (M.Z.M.); (S.S.); (H.A.); (T.J.); (F.B.); (R.N.); (A.H.); (R.T.); (F.A.-R.); (S.S.); (A.W.); (S.A.); (N.A.); (G.A.); (A.A.M.); (F.A.); (T.A.T.); (F.A.-M.)
| | - Fatemah Bahman
- Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (M.Z.M.); (S.S.); (H.A.); (T.J.); (F.B.); (R.N.); (A.H.); (R.T.); (F.A.-R.); (S.S.); (A.W.); (S.A.); (N.A.); (G.A.); (A.A.M.); (F.A.); (T.A.T.); (F.A.-M.)
| | - Rasheeba Nizam
- Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (M.Z.M.); (S.S.); (H.A.); (T.J.); (F.B.); (R.N.); (A.H.); (R.T.); (F.A.-R.); (S.S.); (A.W.); (S.A.); (N.A.); (G.A.); (A.A.M.); (F.A.); (T.A.T.); (F.A.-M.)
| | - Amal Hasan
- Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (M.Z.M.); (S.S.); (H.A.); (T.J.); (F.B.); (R.N.); (A.H.); (R.T.); (F.A.-R.); (S.S.); (A.W.); (S.A.); (N.A.); (G.A.); (A.A.M.); (F.A.); (T.A.T.); (F.A.-M.)
| | - Reeby Thomas
- Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (M.Z.M.); (S.S.); (H.A.); (T.J.); (F.B.); (R.N.); (A.H.); (R.T.); (F.A.-R.); (S.S.); (A.W.); (S.A.); (N.A.); (G.A.); (A.A.M.); (F.A.); (T.A.T.); (F.A.-M.)
| | - Fatema Al-Rashed
- Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (M.Z.M.); (S.S.); (H.A.); (T.J.); (F.B.); (R.N.); (A.H.); (R.T.); (F.A.-R.); (S.S.); (A.W.); (S.A.); (N.A.); (G.A.); (A.A.M.); (F.A.); (T.A.T.); (F.A.-M.)
| | - Steve Shenouda
- Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (M.Z.M.); (S.S.); (H.A.); (T.J.); (F.B.); (R.N.); (A.H.); (R.T.); (F.A.-R.); (S.S.); (A.W.); (S.A.); (N.A.); (G.A.); (A.A.M.); (F.A.); (T.A.T.); (F.A.-M.)
| | - Ajit Wilson
- Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (M.Z.M.); (S.S.); (H.A.); (T.J.); (F.B.); (R.N.); (A.H.); (R.T.); (F.A.-R.); (S.S.); (A.W.); (S.A.); (N.A.); (G.A.); (A.A.M.); (F.A.); (T.A.T.); (F.A.-M.)
| | - Shaima Albeloushi
- Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (M.Z.M.); (S.S.); (H.A.); (T.J.); (F.B.); (R.N.); (A.H.); (R.T.); (F.A.-R.); (S.S.); (A.W.); (S.A.); (N.A.); (G.A.); (A.A.M.); (F.A.); (T.A.T.); (F.A.-M.)
| | - Nourah Almansour
- Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (M.Z.M.); (S.S.); (H.A.); (T.J.); (F.B.); (R.N.); (A.H.); (R.T.); (F.A.-R.); (S.S.); (A.W.); (S.A.); (N.A.); (G.A.); (A.A.M.); (F.A.); (T.A.T.); (F.A.-M.)
| | - Ghadeer Alhamar
- Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (M.Z.M.); (S.S.); (H.A.); (T.J.); (F.B.); (R.N.); (A.H.); (R.T.); (F.A.-R.); (S.S.); (A.W.); (S.A.); (N.A.); (G.A.); (A.A.M.); (F.A.); (T.A.T.); (F.A.-M.)
| | - Ashraf Al Madhoun
- Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (M.Z.M.); (S.S.); (H.A.); (T.J.); (F.B.); (R.N.); (A.H.); (R.T.); (F.A.-R.); (S.S.); (A.W.); (S.A.); (N.A.); (G.A.); (A.A.M.); (F.A.); (T.A.T.); (F.A.-M.)
| | - Fawaz Alzaid
- Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (M.Z.M.); (S.S.); (H.A.); (T.J.); (F.B.); (R.N.); (A.H.); (R.T.); (F.A.-R.); (S.S.); (A.W.); (S.A.); (N.A.); (G.A.); (A.A.M.); (F.A.); (T.A.T.); (F.A.-M.)
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, F-75015 Paris, France
| | - Thangavel Alphonse Thanaraj
- Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (M.Z.M.); (S.S.); (H.A.); (T.J.); (F.B.); (R.N.); (A.H.); (R.T.); (F.A.-R.); (S.S.); (A.W.); (S.A.); (N.A.); (G.A.); (A.A.M.); (F.A.); (T.A.T.); (F.A.-M.)
| | - Heikki A. Koistinen
- Department of Medicine, University of Helsinki and Helsinki University Hospital, 00029 Helsinki, Finland;
- Department of Public Health and Welfare, Finnish Institute for Health and Welfare, P.O. Box 30, 00271 Helsinki, Finland;
- Minerva Foundation Institute for Medical Research, 00290 Helsinki, Finland
| | - Jaakko Tuomilehto
- Department of Public Health and Welfare, Finnish Institute for Health and Welfare, P.O. Box 30, 00271 Helsinki, Finland;
- Department of Public Health, University of Helsinki, 00014 Helsinki, Finland
| | - Fahd Al-Mulla
- Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (M.Z.M.); (S.S.); (H.A.); (T.J.); (F.B.); (R.N.); (A.H.); (R.T.); (F.A.-R.); (S.S.); (A.W.); (S.A.); (N.A.); (G.A.); (A.A.M.); (F.A.); (T.A.T.); (F.A.-M.)
| | - Rasheed Ahmad
- Dasman Diabetes Institute, Dasman 15462, Kuwait; (S.K.); (M.Z.M.); (S.S.); (H.A.); (T.J.); (F.B.); (R.N.); (A.H.); (R.T.); (F.A.-R.); (S.S.); (A.W.); (S.A.); (N.A.); (G.A.); (A.A.M.); (F.A.); (T.A.T.); (F.A.-M.)
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Wang Y, Su K, Sabeva NS, Ji A, van der Westhuyzen DR, Foufelle F, Gao X, Graf GA. GRP78 rescues the ABCG5 ABCG8 sterol transporter in db/db mice. Metabolism 2015; 64:1435-43. [PMID: 26365598 PMCID: PMC4609626 DOI: 10.1016/j.metabol.2015.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 07/31/2015] [Accepted: 08/10/2015] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Mice lacking leptin (ob/ob) or its receptor (db/db) are obese, insulin resistant, and have reduced levels of biliary cholesterol due, in part, to reduced levels of hepatic G5G8. Chronic leptin replacement restores G5G8 abundance and increases biliary cholesterol concentrations, but the molecular mechanisms responsible for G5G8 regulation remain unclear. In the current study, we used a series of mouse models to address potential mechanisms for leptin-mediated regulation of G5G8. METHODS AND RESULTS We acutely replaced leptin in ob/ob mice and deleted hepatic leptin receptors in lean mice. Neither manipulation altered G5G8 abundance or biliary cholesterol. Similarly, hepatic vagotomy had no effect on G5G8. Alternatively, G5G8 may be decreased in ob/ob and db/db mice due to ER dysfunction, the site of G5G8 complex assembly. Overexpression of the ER chaperone GRP78 using an adenoviral vector restores ER function and reduces steatosis in ob/ob mice. Therefore, we determined if AdGRP78 could rescue G5G8 in db/db mice. As in ob/ob mice, AdGRP78 reduced expression of lipogenic genes and plasma triglycerides in the db/db strain. Both G5 and G8 protein levels increased as did total biliary cholesterol, but in the absence of changes in G5 or G8 mRNAs. The increase in G5G8 was associated with increases in a number of proteins, including the ER lectin chaperone, calnexin, a key regulator of G5G8 complex assembly. CONCLUSIONS Leptin signaling does not directly regulate G5G8 abundance. The loss of G5G8 in mice harboring defects in the leptin axis is likely associated with compromised ER function.
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Affiliation(s)
- Yuhuan Wang
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY, USA
| | - Kai Su
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY, USA
| | - Nadezhda S Sabeva
- Department of Neuroscience, Universidad Central del Caribe, Bayamón, PR, USA
| | - Ailing Ji
- Department of Internal Medicine and Molecular, University of Kentucky, Lexington, KY, USA; Department of Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Deneys R van der Westhuyzen
- Graduate Center for Nutritional Sciences, Saha Cardiovascular Research Center and Barnstable Brown Kentucky Diabetes and Obesity Center, Lexington, KY, USA; Department of Internal Medicine and Molecular, University of Kentucky, Lexington, KY, USA; Department of Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Fabienne Foufelle
- INSERM, UMR-S 872, Centre de Recherches des Cordeliers, 15 rue de L'école de Médecine, Paris, France
| | - Xia Gao
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
| | - Gregory A Graf
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY, USA; Graduate Center for Nutritional Sciences, Saha Cardiovascular Research Center and Barnstable Brown Kentucky Diabetes and Obesity Center, Lexington, KY, USA.
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Iglesias-Gato D, Chuan YC, Wikström P, Augsten S, Jiang N, Niu Y, Seipel A, Danneman D, Vermeij M, Fernandez-Perez L, Jenster G, Egevad L, Norstedt G, Flores-Morales A. SOCS2 mediates the cross talk between androgen and growth hormone signaling in prostate cancer. Carcinogenesis 2013; 35:24-33. [PMID: 24031028 DOI: 10.1093/carcin/bgt304] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
UNLABELLED Anabolic signals such as androgens and the growth hormone/insulin-like growth factor 1 (GH/IGF-1) axis play an essential role in the normal development of the prostate but also in its malignant transformation. In this study, we investigated the role of suppressor of cytokine signaling 2 (SOCS2) as mediator of the cross talk between androgens and GH signals in the prostate and its potential role as tumor suppressor in prostate cancer (PCa). We observed that SOCS2 protein levels assayed by immunohistochemistry are elevated in hormone therapy-naive localized prostatic adenocarcinoma in comparison with benign tissue. In contrast, however, castration-resistant bone metastases exhibit reduced levels of SOCS2 in comparison with localized or hormone naive, untreated metastatic tumors. In PCa cells, SOCS2 expression is induced by androgens through a mechanism that requires signal transducer and activator of transcription 5 protein (STAT5) and androgen receptor-dependent transcription. Consequentially, SOCS2 inhibits GH activation of Janus kinase 2, Src and STAT5 as well as both cell invasion and cell proliferation in vitro. In vivo, SOCS2 limits proliferation and production of IGF-1 in the prostate in response to GH. Our results suggest that the use of GH-signaling inhibitors could be of value as a complementary treatment for castration-resistant PCa. SUMMARY Androgen induced SOCS2 ubiquitin ligase expression and inhibited GH signaling as well as cell proliferation and invasion in PCa, whereas reduced SOCS2 was present in castration-resistant cases. GH-signaling inhibitors might be a complementary therapeutic option for advanced PCa.
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Affiliation(s)
- Diego Iglesias-Gato
- Molecular Endocrinology Group, Department of Disease Biology, The Novo Nordisk Foundation Center for Protein Research, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
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Alemán G, Ortiz V, Contreras AV, Quiroz G, Ordaz-Nava G, Langley E, Torres N, Tovar AR. Hepatic amino acid-degrading enzyme expression is downregulated by natural and synthetic ligands of PPARα in rats. J Nutr 2013; 143:1211-8. [PMID: 23761645 DOI: 10.3945/jn.113.176354] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Body nitrogen retention is dependent on the amount of dietary protein consumed, as well as the fat and carbohydrate content in the diet, due to the modulation of amino acid oxidation. PPARα is a transcription factor involved in the upregulation of the expression of enzymes of fatty acid oxidation. However, the role of putative PPARα response elements (PPREs) in the promoter of several amino acid-degrading enzymes (AADEs) is not known. The aim of this work was to study the effect of the synthetic ligand Wy 14643 and the natural ligands palmitate, oleate, and linoleate in rats fed graded concentrations of dietary protein (6, 20, or 50 g/100 g of total diet) on the expression of the AADEs histidase, serine dehydratase, and tyrosine aminotransferase. Thus, we fed male Wistar rats diets containing 6, 20, or 50% casein for 10 d. The results showed that addition of Wy 14643 to the diet significantly reduced the expression of the AADEs. Furthermore, the incubation of hepatocytes with natural ligands of PPARα or feeding rats with diets containing soybean oil, safflower oil, lard, or coconut oil as sources of dietary fat significantly repressed the expression of the AADEs. Gene reporter assays and mobility shift assays demonstrated that the PPRE located at -482 bp of the histidase gene actively bound PPARα in rat hepatocytes. These data indicate that PPARα ligands may reduce amino acid catabolism in rats.
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Affiliation(s)
- Gabriela Alemán
- Departamento de Fisiología de la Nutrición, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico, DF, Mexico
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Conlon LE, King RD, Moran NE, Erdman JW. Coconut oil enhances tomato carotenoid tissue accumulation compared to safflower oil in the Mongolian gerbil ( Meriones unguiculatus ). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:8386-8394. [PMID: 22866697 DOI: 10.1021/jf301902k] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Evidence suggests that monounsaturated and polyunsaturated fats facilitate greater absorption of carotenoids than saturated fats. However, the comparison of consuming a polyunsaturated fat source versus a saturated fat source on tomato carotenoid bioaccumulation has not been examined. The goal of this study was to determine the influence of coconut oil and safflower oil on tomato carotenoid tissue accumulation in Mongolian gerbils ( Meriones unguiculatus ) fed a 20% fat diet. Coconut oil feeding increased carotenoid concentrations among many compartments including total carotenoids in the serum (p = 0.0003), adrenal glandular phytoene (p = 0.04), hepatic phytofluene (p = 0.0001), testicular all-trans-lycopene (p = 0.01), and cis-lycopene (p = 0.006) in the prostate-seminal vesicle complex compared to safflower oil. Safflower oil-fed gerbils had greater splenic lycopene concentrations (p = 0.006) compared to coconut oil-fed gerbils. Coconut oil feeding increased serum cholesterol (p = 0.0001) and decreased hepatic cholesterol (p = 0.0003) compared to safflower oil. In summary, coconut oil enhanced tissue uptake of tomato carotenoids to a greater degree than safflower oil. These results may have been due to the large proportion of medium-chain fatty acids in coconut oil, which might have caused a shift in cholesterol flux to favor extrahepatic carotenoid tissue deposition.
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Affiliation(s)
- Lauren E Conlon
- Division of Nutritional Sciences, 905 South Goodwin Avenue, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
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Bjermo H, Iggman D, Kullberg J, Dahlman I, Johansson L, Persson L, Berglund J, Pulkki K, Basu S, Uusitupa M, Rudling M, Arner P, Cederholm T, Ahlström H, Risérus U. Effects of n-6 PUFAs compared with SFAs on liver fat, lipoproteins, and inflammation in abdominal obesity: a randomized controlled trial. Am J Clin Nutr 2012; 95:1003-12. [PMID: 22492369 DOI: 10.3945/ajcn.111.030114] [Citation(s) in RCA: 361] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Replacing SFAs with vegetable PUFAs has cardiometabolic benefits, but the effects on liver fat are unknown. Increased dietary n-6 PUFAs have, however, also been proposed to promote inflammation-a yet unproven theory. OBJECTIVE We investigated the effects of PUFAs on liver fat, systemic inflammation, and metabolic disorders. DESIGN We randomly assigned 67 abdominally obese subjects (15% had type 2 diabetes) to a 10-wk isocaloric diet high in vegetable n-6 PUFA (PUFA diet) or SFA mainly from butter (SFA diet), without altering the macronutrient intake. Liver fat was assessed by MRI and magnetic resonance proton (1H) spectroscopy (MRS). Proprotein convertase subtilisin/kexin type-9 (PCSK9, a hepatic LDL-receptor regulator), inflammation, and adipose tissue expression of inflammatory and lipogenic genes were determined. RESULTS A total of 61 subjects completed the study. Body weight modestly increased but was not different between groups. Liver fat was lower during the PUFA diet than during the SFA diet [between-group difference in relative change from baseline; 16% (MRI; P < 0.001), 34% (MRS; P = 0.02)]. PCSK9 (P = 0.001), TNF receptor-2 (P < 0.01), and IL-1 receptor antagonist (P = 0.02) concentrations were lower during the PUFA diet, whereas insulin (P = 0.06) tended to be higher during the SFA diet. In compliant subjects (defined as change in serum linoleic acid), insulin, total/HDL-cholesterol ratio, LDL cholesterol, and triglycerides were lower during the PUFA diet than during the SFA diet (P < 0.05). Adipose tissue gene expression was unchanged. CONCLUSIONS Compared with SFA intake, n-6 PUFAs reduce liver fat and modestly improve metabolic status, without weight loss. A high n-6 PUFA intake does not cause any signs of inflammation or oxidative stress. Downregulation of PCSK9 could be a novel mechanism behind the cholesterol-lowering effects of PUFAs. This trial was registered at clinicaltrials.gov as NCT01038102.
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Affiliation(s)
- Helena Bjermo
- Department of Public Health, Uppsala University, Uppsala, Sweden
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Gustavsson C, Soga T, Wahlström E, Vesterlund M, Azimi A, Norstedt G, Tollet-Egnell P. Sex-dependent hepatic transcripts and metabolites in the development of glucose intolerance and insulin resistance in Zucker diabetic fatty rats. J Mol Endocrinol 2011; 47:129-43. [PMID: 21673048 DOI: 10.1530/jme-11-0007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Male Zucker diabetic fatty (mZDF) rats spontaneously develop type 2 diabetes, whereas females only become diabetic when fed a diabetogenic high-fat diet (high-fat-fed female ZDF rat, HF-fZDF). The aim of this study was to investigate if differences in liver functions could provide clues to this sex difference. Non-diabetic obese fZDF rats were compared with either mZDF or HF-fZDF regarding hepatic molecular profiles, to single out those components that might be protective in the females. High-fat feeding in fZDF led to enhanced weight gain, increased blood glucose and insulin levels, reduced insulin sensitivity and a trend towards reduced glucose tolerance, indicative of a prediabetic state. mZDF rats were diabetic, with low levels of insulin, high levels of glucose, reduced insulin sensitivity and impaired glucose tolerance. Transcript profiling and capillary electrophoresis time-of-flight mass spectrometry were used to indentify hepatic transcripts and metabolites that might be related to this. Many diet-induced alterations in transcript and metabolite levels in female rats were towards a 'male-like' phenotype, including reduced lipogenesis, increased fatty acid (FA) oxidation and increased oxidative stress responses. Alterations detected at the level of hepatic metabolites, indicated lower capacity for glutathione (GSH) production in male rats, and higher GSH turnover in females. Taken together, this could be interpreted as if anabolic pathways involving lipogenesis and lipid output might limit the degree of FA oxidation and oxidative stress in female rats. Together with a greater capacity to produce GSH, these hepatic sex differences might contribute to the sex-different development of diabetes in ZDF rats.
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Affiliation(s)
- Carolina Gustavsson
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
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Gustavsson C, Yassin K, Wahlström E, Cheung L, Lindberg J, Brismar K, Ostenson CG, Norstedt G, Tollet-Egnell P. Sex-different hepaticglycogen content and glucose output in rats. BMC BIOCHEMISTRY 2010; 11:38. [PMID: 20863371 PMCID: PMC2955586 DOI: 10.1186/1471-2091-11-38] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Accepted: 09/23/2010] [Indexed: 02/08/2023]
Abstract
Background Genes involved in hepatic metabolism have a sex-different expression in rodents. To test whether male and female rat livers differ regarding lipid and carbohydrate metabolism, whole-genome transcript profiles were generated and these were complemented by measurements of hepatic lipid and glycogen content, fatty acid (FA) oxidation rates and hepatic glucose output (HGO). The latter was determined in perfusates from in situ perfusion of male and female rat livers. These perfusates were also analysed using nuclear magnetic resonance (NMR) spectroscopy to identify putative sex-differences in other liver-derived metabolites. Effects of insulin were monitored by analysis of Akt-phosphorylation, gene expression and HGO after s.c. insulin injections. Results Out of approximately 3 500 gene products being detected in liver, 11% were significantly higher in females, and 11% were higher in males. Many transcripts for the production of triglycerides (TG), cholesterol and VLDL particles were female-predominant, whereas genes for FA oxidation, gluconeogenesis and glycogen synthesis were male-predominant. Sex-differences in mRNA levels related to metabolism were more pronounced during mild starvation (12 h fasting), as compared to the postabsorptive state (4 h fasting). No sex-differences were observed regarding hepatic TG content, FA oxidation rates or blood levels of ketone bodies or glucose. However, males had higher hepatic glycogen content and higher HGO, as well as higher ratios of insulin to glucagon levels. Based on NMR spectroscopy, liver-derived lactate was also higher in males. HGO was inhibited by insulin in parallel with increased phosphorylation of Akt, without any sex-differences in insulin sensitivity. However, the degree of Thr172-phosphorylated AMP kinase (AMPK) was higher in females, indicating a higher degree of AMPK-dependent actions. Conclusions Taken together, males had higher ratios of insulin to glucagon levels, higher levels of glycogen, lower degree of AMPK phosphorylation, higher expression of gluconeogenic genes and higher hepatic glucose output. Possibly these sex-differences reflect a higher ability for the healthy male rat liver to respond to increased energy demands.
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