Abstract
Adipose tissue secretes numerous pro-inflammatory cytokines, such as interleukin (IL)-6 and tumor necrosis factor (TNF)-α that can lead to insulin resistance (IR). In the liver, both IL-6 and TNF-α induce IR by inhibiting phosphorylation or ubiquitination of IRS1. In IR development, Fe is a risk factor in type-2 diabetes development. We studied the expression of genes related to inflammation, hypoxia, and mitochondrial function in hepatic (HepG2) and adipose (3T3-L1) cells. HepG2 and 3T3-L1 cells were incubated with 20 μM Fe, 40 μM Fe, or 40 μM Fe/20 mM glucose for 7 days and then challenged with 20 ng/ml IL-6 and/or 100 μM CoCl2 for 20 h. We measured intracellular Fe levels and the relative expression of hepcidin, NF-κB, IL-6, TNF-α, hypoxia inducible factor 1α (HIF-1α), and mitofusin 2 (Mfn-2) mRNA using qRT-PCR. The intracellular Fe concentration in HepG2 cells did not change with 20 or 40 μM Fe. However, levels were decreased with Fe/glucose and IL-6 and/or CoCl2. 3T3-L1 cells showed an increase in intracellular Fe with high Fe plus either IL-6 or CoCl2. HepG2 cells incubated with 40 μM Fe alone or Fe/glucose and challenged with IL-6 and/or CoCl2 showed increased IL-6, NF-κB, and TNF-α mRNA expression and decreased mRNA expression of Mfn-2 in all experimental conditions. 3T3-L1 cells incubated with 40 μM Fe alone or Fe/glucose and challenged with IL-6 showed increased NF-κB mRNA expression and decreased Mfn-2 expression in all experimental conditions. Thus, high Fe, inflammation, and hypoxia trigger the expression of genes related to inflammation and Fe metabolism in HepG2 cells, in 3T3-L1 cells the same stimuli increased NF-kB and hepcidin expression.
Similar content being viewed by others
References
Aguirre V, Uchida T, Yenush L, Davis R, White MF (2000) The c-Jun NH(2)-terminal kinase promotes insulin resistance during association with insulin receptor substrate-1 and phosphorylation of Ser(307). J Biol Chem 275:9047–9054
Aguirre V, Werner ED, Giraud J, Lee YH, Shoelson SE, White MF (2002) Phosphorylation of Ser307 in insulin receptor substrate-1 blocks interactions with the insulin receptor and inhibits insulin action. J Biol Chem 277:1531–1537
Bach D, Pich S, Soriano FX, Vega N, Baumgartner B, Oriola J, Daugaard JR, Lloberas J, Camps M, Zierath JR, Rabasa-Lhoret R, Wallberg-Henriksson H, Laville M, Palacin M, Vidal H, Rivera F, Brand M, Zorzano A (2003) Mitofusin-2 determines mitochondrial network architecture and mitochondrial metabolism: a novel regulatory mechanism altered in obesity. J Biol Chem 278:17190–17197
Bach D, Naon D, Pich S, Soriano F, Vega N, Rieusset J, Laville M, Guillet C, Boirie Y, Wallberg-Henrikson H, Manco M, Calvani M, Castagneto M, Palacín M, Mingrone G, Zierath J, Vidal H, Zorzano A (2005) Expression of Mfn2, the Charcot-Marie-Tooth neuropathy type 2A gene, in human skeletal muscle. Effects of type 2 diabetes, obesity, weight loss, and the regulatory role of tumor necrosis α and interleukin 6. Diabetes 54:2685–2693
Bastard JP, Maachi M, Lagathu C, Kim MJ, Caron M, Vidal H, Capeau J, Feve B (2006) Recent advances in the relationship between obesity, inflammation, and insulin resistance. Eur Cytokine Netw 17:4–12
Cinti S, Mitchell G, Barbatelli G, Murano I, Ceresi E, Faloia E, Wang S, Greenberg AS, Obin MS (2005) Adipocyte death defines macrophage localization and function in adipose tissue of obese mice and humans. J Lipid Res 46:2347–2355
Domenico I, Zhang T, Koening C, Branch R, London N, Lo E, Daynes R, Hushner J, Li D, Ward D, Kaplan J (2010) Hepcidin mediates transcriptional changes that modulate acute cytokine-induced inflammatory responses in mice. J Clin Invest 120:2395–2405
Eder K, Baffy N, Falus A, Fulop A (2009) The major inflammatory mediator interleukin 6 and obesity. Inflamm Res 58:727–738
Everett MV, Antal CE, Crawford DL (2010) The effect of short-term hypoxic exposure on metabolic gene expression. J Exp Zool Genet Physiol 317:9–23
Fain JN, Madan AK, Hiler ML, Cheema P, Bahouth SW (2004) Comparison of the release of adipokines by adipose tissue, adipose tissue matrix, and adipocytes from visceral and subcutaneous abdominal adipose tissues of obese humans. Endocrinology 145:2273–2276
Fernández-Real JM, Lopez-Bermejo A, Ricart W (2002) Cross-talk between iron metabolism and diabetes. Diabetes 51:2348–2354
Fleming RE, Feng Q, Britton RS (2011) Knockout mouse models of iron homeostasis. Annu Rev Nutr 21:117–137
Furukawa S, Fujita T, Shimabukuro M, Iwaki M, Yamada Y, Nakajima Y, Nakayama O, Makishima M, Matsuda M, Shimomura I (2004) Increased oxidative stress in obesity and its impact on metabolic syndrome. J Clin Invest 114:1752–1761
Galic S, Oakhill JS, Steinberg GR (2010) Adipose tissue as an endocrine organ. Mol Cell Endocrinol 316:129–139
Ganz T, Nemeth E (2011) Hepcidin and disorders of iron metabolism. Annu Rev Med 62:347–360
Gao J, Chen J, Kramer M (2009) Interaction of the hereditary hemochromatosis protein HFE with transferrin receptor 2 is required for transferrin-induced hepcidin expression. Cell Metab 9:217–227
Hartmann G, Tschöp M, Fischer R, Bidlingmaier C, Riepl R, Tschöp K, Hautmann H, Endres S, Toepfer M (2000) High altitude increases circulating interleukin-6, interleukin-1 receptor antagonist and C-reactive protein. Cytokine 12:246–252
Hosogai N, Fukuhara A, Oshima K, Miyata Y, Tanaka S, Segawa K, Furukawa S, Tochino Y, Komuro R, Matsuda M, Shimomura I (2007) Adipose tissue hypoxia in obesity and its impact on adipocytokine dysregulation. Diabetes 56:901–911
Hotamisligil GS (2006) Inflammation and metabolic disorders. Nature 444:860–867
Huang J, Jones D, Luo B, Sanderson M, Soto J, Dale E, Cooksey R, McClain D (2011) Iron overload and diabetes risk: a shift from glucose to fatty acid oxidation and increased hepatic glucose production in a mouse model of hereditary hemochromatosis. Diabetes 60:80–88
Jiang R, Ascherio J, Stampfer MJ, Willett WC, Hu FB (2004) Dietary iron intake and blood donations in relation to risk of type 2 diabetes in men: a prospective cohort study. Am J Clin Nutr 79:70–75
Klover P, Zimmers T, Koniaris L, Mooney R (2003) Chronic exposure to interleukin 6 causes hepatic insulin resistance in mice. Diabetes 52:2784–2789
Lebrun P, Obberghen Van (2008) SOCS proteins causing trouble in insulin action. Acta Physiol 192:29–36
Lin Y, Berg AH, Iyengar P, Lam TK, Giacca A, Combs TP, Rajala MW, Du X, Rollman B, Li W, Hawkins M, Barzilai N, Rhodes CJ, Fantus IG, Brownlee M, Scherer PE (2005) The hyperglycemia-induced inflammatory response in adipocytes: the role of reactive oxygen species. J Biol Chem 280:4617–4626
Nemeth E, Ganz T (2006) Regulation of iron metabolism by hepcidin. Annu Rev Nutr 26:323–342
Nemeth E, Valore EV, Territo M, Schiller G, Lichtenstein A, Ganz T (2003) Hepcidin, a putative mediator of anemia of inflammation, is a type II acute phase protein. Blood 101:2461–2463
Nemeth E, Rivera S, Gabayan V, Keller C, Taudorf S, Pedersen B, Ganz T (2004) IL-6 mediates hypoferremia of inflammation by inducing the synthesis of the iron regulatory hormone hepcidin. J Clin Invest 113:1271–1276
Pasarica M, Sereda OR, Redman LM, Albarado DC, Hymel DT, Roan LE, Rood JC, Burk DH, Smith SR (2009) Reduced adipose tissue oxygenation in human obesity: evidence for rarefaction, macrophage chemotaxis, and inflammation without an angiogenic response. Diabetes 58:718–725
Pfaffl M (2001) A new mathematical model for relative quantification in real time RT-PCR. Nucleic Acids Res 29:2002–2007
Pich S, Bach D, Briones P, Liesa M, Camps M, Testar X, Palacin M, Zorzano A (2005) The Charcot-Marie-Tooth type 2A product, Mfn2, up-regulates fuel oxidation through expression of OXPHOS system. Hum Mol Genet 14:1405–1415
Popa C, Netea MG, van Riel PL, van der Meer JW, Stalenhoef AF (2007) The role of TNF- alpha in chronic inflammatory conditions, intermediary metabolism, and cardiovascular risk. J Lipid Res 48:751–762
Rajpathak S, Crandall J, Wylie-Rosett J, Kabat G, Rohan T, Hu F (2009) The role of iron in type 2 diabetes. Biochim Biophys Acta 1790:671–681
Rasouli N, Kern PA (2008) Adipocytokines and metabolic complications of obesity. J Clin Endocrin Metab 93:S64–S73
Rui L, Yuan M, Frantz D, Shoelson S, White M (2002) SOCS-1 and SOCS-3 block insulin signaling by ubiquitin mediated degradation of IRS1 and IRS2. J Biol Chem 277:42394–42398
Rutkowski JM, Davis KE, Scherer PE (2009) Mechanisms of obesity and related pathologies: the macro- and microcirculation of adipose tissue. FEBS J 276:5738–5746
Santel A, Fuller MT (2001) Control of mitochondrial morphology by a human mitofusin. J Cell Sci 114:867–874
Schmidt PJ, Toran PT, Giannetti AM (2008) The transferrin receptor modulates Hfe-dependent regulation of hepcidin expression. Cell Metab 7:205–214
Senn J, Klover P, Nowak I, Zimmers T, Koniaris L, Furlanetto R, Mooney R (2003) Suppressor of cytokine signaling (SOCS-3), a potential mediator of interleukin-6-dependent insulin resistance in hepatocytes. J Biol Chem 278:13740–13746
Tajima S, Ikeda Y, Sawada K, Yamano N, Horinouchi Y, Kihira Y, Ishizawa K, Izawa-Ishizawa Y, Kawazoe K, Tomita S, Minakuchi K, Tsuchiya K, Tamaki T (2012) Iron reduction by deferoxamine leads to amelioration of adiposity via the regulation of oxidative stress and inflammation in obese and type 2 diabetes KKAy mice. Am J Physiol Endocrinol Metal 302:E77–E86
Tarantino G (2011) JNKs, insulin resistance and inflammation: a possible link between NAFLD and coronary artery disease. World J Gastroenterol 17:3785–3794
Tianzheng Yu, Robotham J, Yoon Y (2006) Increased production of reactive oxygen species in hyperglycemic conditions requires dynamic change of mitochondrial morphology. PNAS 103:2653–2658
Trayhurn P, Wood. IS (2004) Adipokines: inflammation and the pleiotropic role of white adipose tissue. Br J Nutr 92:347–355
Truksa J, Peng H, Lee P, Beutler E (2007) Different regulatory elements are required for response of hepcidin to interleukin-6 and bone morphogenetic proteins 4 and 9. Br J Haematol 139:138–147
Valenti L, Fracanzani AL, Dongiovani P, Bugianesi E, Marchesini G, Manzini P, Vanni E, Fargion S (2007) Iron depletion by phlebotomy improves insulin resistance in patients with nonalcoholic fatty liver disease and hyperferritinemia: evidence from a case-control study. Am J Gastroenterol 102:1251–1258
Vokurka M, Lacinova Z, Kremen J, Kopecky P, Blaha J, Pelinkova K, Haluzik M, Necas E (2010) Hepcidin expression in adipose tissue increases during cardiac surgery. Physiol Res 59:393–400
Weisberg SP, McCann D, Desai M, Rosenbaum M, Leibel RL, Ferrante AW Jr (2003) Obesity is associated with macrophage accumulation in adipose tissue. J Clin Invest 112:1796–1808
Wellen KE, Hotamisligil GS (2003) Obesity-induced inflammatory changes in adipose tissue. J Clin Invest 112:1785–1788
Wellen KE, Hotamisligil GS (2005) Inflammation, stress, and diabetes. J Clin Invest 115:1111–1119
Wrighting DM, Andrews NC (2006) Interleukin-6 induces hepcidin expression through STAT3. Blood 108:3204–3209
Xu H, Barnes GT, Yang Q, Tan G, Yang D, Chou CJ, Sole J, Nichols A, Ross JS, Tartaglia LA, Chen H (2003) Chronic inflammation in fat plays a crucial role in the development of obesity-related insulin resistance. J Clin Invest 112:1821–1830
Ye J, Gao Z, Yin J, He Q (2007) Hypoxia is a potential risk factor for chronic inflammation and adiponectin reduction in adipose tissue of ob/ob and dietary obese mice. Am J Physiol Endocrinol Metab 293:E1118–E1128
Yoshimura A, Naka T, Kubo M (2007) SOCS proteins, cytokine signaling and immune regulation. Nat Rev Immunol 7:454–465
Zhang X, Rovin B (2010) Hepcidin expression by human monocytes in response to adhesion and pro-inflammatory cytokines. Biochim Piophys Acta 1800:1262–1267
Zick Y (2003) Role of Ser/Thr kinases in the uncoupling of insulin signaling. Int J Obes Relat Metab Disord 27(Suppl 3):S56–S60
Acknowledgments
This research was supported by the Diabetes and Endocrinology Society of Chile (SOCHED) and FONDECYT No. 1085173 and 1110080.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Andrews, M., Arredondo, M. Hepatic and adipocyte cells respond differentially to iron overload, hypoxic and inflammatory challenge. Biometals 25, 749–759 (2012). https://doi.org/10.1007/s10534-012-9543-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10534-012-9543-9