Activation of the omega-3 fatty acid receptor GPR120 mediates anti-inflammatory actions in immortalized hypothalamic neurons

Journal of Neuroinflammation

Denise D Belsham²  Leigh Wellhauser¹ 

[1] Department of Physiology, Faculty of Medicine, University of Toronto, 1 King’s College Circle, Medical Sciences Building 3344, Toronto, Ontario M5S 1A8, Canada;Division of Cellular and Molecular Biology, Toronto General Hospital Research Institute, University Health Network, 610 University Avenue, Toronto, Ontario M5G 2 M9, Canada

关键词: Docosahexaenoic acid;    Tumor necrosis factor α;    Neuronal cell line;    Signal transduction;    Hypothalamus;    Inflammation;   

Others  :  810613
DOI  :  10.1186/1742-2094-11-60

 received in 2014-01-19, accepted in 2014-03-11,  发布年份 2014

【 摘 要 】

Background

Overnutrition and the ensuing hypothalamic inflammation is a major perpetuating factor in the development of metabolic diseases, such as obesity and diabetes. Inflamed neurons of the CNS fail to properly regulate energy homeostasis leading to pathogenic changes in glucose handling, feeding, and body weight. Hypothalamic neurons are particularly sensitive to pro-inflammatory signals derived locally and peripherally, and it is these neurons that become inflamed first upon high fat feeding. Given the prevalence of metabolic disease, efforts are underway to identify therapeutic targets for this inflammatory state. At least in the periphery, omega-3 fatty acids and their receptor, G-protein coupled receptor 120 (GPR120), have emerged as putative targets. The role for GPR120 in the hypothalamus or CNS in general is poorly understood.

Methods

Here we introduce a novel, immortalized cell model derived from the rat hypothalamus, rHypoE-7, to study GPR120 activation at the level of the individual neuron. Gene expression levels of pro-inflammatory cytokines were studied by quantitative reverse transcriptase-PCR (qRT-PCR) upon exposure to tumor necrosis factor α (TNFα) treatment in the presence or absence of the polyunsaturated omega-3 fatty acid docosahexaenoic acid (DHA). Signal transduction pathway involvement was also studied using phospho-specific antibodies to key proteins by western blot analysis.

Results

Importantly, rHypoE-7 cells exhibit a transcriptional and translational inflammatory response upon exposure to TNFα and express abundant levels of GPR120, which is functionally responsive to DHA. DHA pretreatment prevents the inflammatory state and this effect was inhibited by the reduction of endogenous GPR120 levels. GPR120 activates both AKT (protein kinase b) and ERK (extracellular signal-regulated kinase); however, the anti-inflammatory action of this omega-3 fatty acid (FA) receptor is AKT- and ERK-independent and likely involves the GPR120-transforming growth factor-β-activated kinase 1 binding protein (TAB1) interaction as identified in the periphery.

Conclusions

Taken together, GPR120 is functionally active in the hypothalamic neuronal line, rHypoE-7, wherein it mediates the anti-inflammatory actions of DHA to reduce the inflammatory response to TNFα.

【 授权许可】

   
2014 Wellhauser and Belsham; licensee BioMed Central Ltd.

【 图 表 】

Figure 1.

Figure 2.

Figure 3.

Figure 4.

Figure 5.

Figure 6.

Figure 1.

Figure 2.

Figure 3.

Figure 4.

Figure 5.

Figure 6.

【 参考文献 】

• [1]Shoelson SE, Lee J, Goldfine AB: Inflammation and insulin resistance. J Clin Investig 2006, 116:1793-1801.
• [2]Hotamisligil GS, Arner P, Caro JF, Atkinson RL, Spiegelman BM: Increased adipose tissue expression of tumor necrosis factor-alpha in human obesity and insulin resistance. J Clin Invest 1995, 95:2409-2415.
• [3]Spranger J, Kroke A, Mohlig M, Hoffmann K, Bergmann MM, Ristow M, Boeing H, Pfeiffer AF: Inflammatory cytokines and the risk to develop type 2 diabetes: results of the prospective population-based European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study. Diabetes 2003, 52:812-817.
• [4]De Souza CT, Araujo EP, Bordin S, Ashimine R, Zollner RL, Boschero AC, Saad MJ, Velloso LA: Consumption of a fat-rich diet activates a proinflammatory response and induces insulin resistance in the hypothalamus. Endocrinology 2005, 146:4192-4199.
• [5]Laflamme N, Rivest S: Effects of systemic immunogenic insults and circulating proinflammatory cytokines on the transcription of the inhibitory factor kappaB alpha within specific cellular populations of the rat brain. J Neurochem 1999, 73:309-321.
• [6]Milanski M, Degasperi G, Coope A, Morari J, Denis R, Cintra DE, Tsukumo DM, Anhe G, Amaral ME, Takahashi HK, Curi R, Oliveira HC, Carvalheira JB, Bordin S, Saad MJ, Velloso LA: Saturated fatty acids produce an inflammatory response predominantly through the activation of TLR4 signaling in hypothalamus: implications for the pathogenesis of obesity. J Neurosci 2009, 29:359-370.
• [7]Quan N, Stern EL, Whiteside MB, Herkenham M: Induction of pro-inflammatory cytokine mRNAs in the brain after peripheral injection of subseptic doses of lipopolysaccharide in the rat. J Neuroimmunol 1999, 93:72-80.
• [8]Thaler JP, Yi CX, Schur EA, Guyenet SJ, Hwang BH, Dietrich MO, Zhao X, Sarruf DA, Izgur V, Maravilla KR, Nguyen HT, Fischer JD, Matsen ME, Wisse BE, Morton GJ, Horvath TL, Baskin DG, Tschöp MH, Schwartz MW: Obesity is associated with hypothalamic injury in rodents and humans. J Clin Invest 2012, 122:153-162.
• [9]Prada PO, Zecchin HG, Gasparetti AL, Torsoni MA, Ueno M, Hirata AE, Amaral ME C d, Hoer NF, Boschero AC, Saad MJ: Western diet modulates insulin signaling, c-Jun N-terminal kinase activity, and insulin receptor substrate-1ser307 phosphorylation in a tissue-specific fashion. Endocrinology 2005, 146:1576-1587.
• [10]Milanski M, Arruda AP, Coope A, Ignacio-Souza LM, Nunez CE, Roman EA, Romanatto T, Pascoal LB, Caricilli AM, Torsoni MA, Prada PO, Saad MJ, Velloso LA: Inhibition of hypothalamic inflammation reverses diet-induced insulin resistance in the liver. Diabetes 2012, 61:1455-1462.
• [11]Arruda AP, Milanski M, Coope A, Torsoni AS, Ropelle E, Carvalho DP, Carvalheira JB, Velloso LA: Low-grade hypothalamic inflammation leads to defective thermogenesis, insulin resistance, and impaired insulin secretion. Endocrinology 2011, 152:1314-1326.
• [12]Wang X, Ge A, Cheng M, Guo F, Zhao M, Zhou X, Liu L, Yang N: Increased hypothalamic inflammation associated with the susceptibility to obesity in rats exposed to high-fat diet. Exp Diabetes Res 2012, 2012:847246.
• [13]Posey KA, Clegg DJ, Printz RL, Byun J, Morton GJ, Vivekanandan-Giri A, Pennathur S, Baskin DG, Heinecke JW, Woods SC, Schwartz MW, Niswender KD: Hypothalamic proinflammatory lipid accumulation, inflammation, and insulin resistance in rats fed a high-fat diet. Am J Physiol Endocrinol Metab 2009, 296:E1003-E1012.
• [14]Zhang X, Zhang G, Zhang H, Karin M, Bai H, Cai D: Hypothalamic IKKbeta/NF-kappaB and ER stress link overnutrition to energy imbalance and obesity. Cell 2008, 135:61-73.
• [15]Oh IS, Thaler JP, Ogimoto K, Wisse BE, Morton GJ, Schwartz MW: Central administration of interleukin-4 exacerbates hypothalamic inflammation and weight gain during high-fat feeding. Am J Physiol Endocrinol Metab 2010, 299:E47-E53.
• [16]Purkayastha S, Zhang G, Cai D: Uncoupling the mechanisms of obesity and hypertension by targeting hypothalamic IKK-beta and NF-kappaB. Nat Med 2011, 17:883-887.
• [17]Fredriksson R, Hoglund PJ, Gloriam DE, Lagerstrom MC, Schioth HB: Seven evolutionarily conserved human rhodopsin G protein-coupled receptors lacking close relatives. FEBS Lett 2003, 554:381-388.
• [18]Hirasawa A, Tsumaya K, Awaji T, Katsuma S, Adachi T, Yamada M, Sugimoto Y, Miyazaki S, Tsujimoto G: Free fatty acids regulate gut incretin glucagon-like peptide-1 secretion through GPR120. Nat Med 2005, 11:90-94.
• [19]Oh DY, Talukdar S, Bae EJ, Imamura T, Morinaga H, Fan W, Li P, Lu WJ, Watkins SM, Olefsky JM: GPR120 is an omega-3 fatty acid receptor mediating potent anti-inflammatory and insulin-sensitizing effects. Cell 2010, 142:687-698.
• [20]Ichimura A, Hirasawa A, Poulain-Godefroy O, Bonnefond A, Hara T, Yengo L, Kimura I, Leloire A, Liu N, Iida K, Choquet H, Besnard P, Lecoeur C, Vivequin S, Ayukawa K, Takeuchi M, Ozawa K, Tauber M, Maffeis C, Morandi A, Buzzetti R, Elliott P, Pouta A, Jarvelin MR, Körner A, Kiess W, Pigeyre M, Caiazzo R, Van Hul W, Van Gaal L, et al.: Dysfunction of lipid sensor GPR120 leads to obesity in both mouse and human. Nature 2012, 483:350-354.
• [21]Cintra DE, Ropelle ER, Moraes JC, Pauli JR, Morari J, Souza CT, Grimaldi R, Stahl M, Carvalheira JB, Saad MJ, Velloso LA: Unsaturated fatty acids revert diet-induced hypothalamic inflammation in obesity. PLoS One 2012, 7:e30571.
• [22]Belsham DD, Cai F, Cui H, Smukler SR, Salapatek AM, Shkreta L: Generation of a phenotypic array of hypothalamic neuronal cell models to study complex neuroendocrine disorders. Endocrinology 2004, 145:393-400.
• [23]Gingerich S, Wang X, Lee PK, Dhillon SS, Chalmers JA, Koletar MM, Belsham DD: The generation of an array of clonal, immortalized cell models from the rat hypothalamus: analysis of melatonin effects on kisspeptin and gonadotropin-inhibitory hormone neurons. Neuroscience 2009, 162:1134-1140.
• [24]Chomczynski P, Sacchi N: Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. Anal Biochem 1987, 162:156-159.
• [25]Hotamisligil GS: Endoplasmic reticulum stress and atherosclerosis. Nat Med 2010, 16:396-399.
• [26]Igarashi M, Ma K, Gao F, Kim HW, Greenstein D, Rapoport SI, Rao JS: Brain lipid concentrations in bipolar disorder. J Psychiatr Res 2010, 44:177-182.
• [27]Briscoe CP, Peat AJ, McKeown SC, Corbett DF, Goetz AS, Littleton TR, McCoy DC, Kenakin TP, Andrews JL, Ammala C, Fornwald JA, Ignar DM, Jenkinson S: Pharmacological regulation of insulin secretion in MIN6 cells through the fatty acid receptor GPR40: identification of agonist and antagonist small molecules. Br J Pharmacol 2006, 148:619-628.
• [28]Miyauchi S, Hirasawa A, Iga T, Liu N, Itsubo C, Sadakane K, Hara T, Tsujimoto G: Distribution and regulation of protein expression of the free fatty acid receptor GPR120. Naunyn Schmiedebergs Arch Pharmacol 2009, 379:427-434.
• [29]Watson SJ, Brown AJ, Holliday ND: Differential signaling by splice variants of the human free fatty acid receptor GPR120. Mol Pharmacol 2012, 81:631-642.
• [30]Yan Y, Jiang W, Spinetti T, Tardivel A, Castillo R, Bourquin C, Guarda G, Tian Z, Tschopp J, Zhou R: Omega-3 fatty acids prevent inflammation and metabolic disorder through inhibition of NLRP3 inflammasome activation. Immunity 2013, 38:1154-1163.
• [31]Chung KY, Day PW, Velez-Ruiz G, Sunahara RK, Kobilka BK: Identification of GPCR-interacting cytosolic proteins using HDL particles and mass spectrometry-based proteomic approach. PLoS One 2013, 8:e54942.
• [32]Bannenberg GL, Chiang N, Ariel A, Arita M, Tjonahen E, Gotlinger KH, Hong S, Serhan CN: Molecular circuits of resolution: formation and actions of resolvins and protectins. J Immunol 2005, 174:4345-4355.
• [33]Lee HN, Surh YJ: Therapeutic potential of resolvins in the prevention and treatment of inflammatory disorders. Biochem Pharmacol 2012, 84:1340-1350.
• [34]Groeger AL, Cipollina C, Cole MP, Woodcock SR, Bonacci G, Rudolph TK, Rudolph V, Freeman BA, Schopfer FJ: Cyclooxygenase-2 generates anti-inflammatory mediators from omega-3 fatty acids. Nat Chem Biol 2010, 6:433-441.
• [35]Orr SK, Palumbo S, Bosetti F, Mount HT, Kang JX, Greenwood CE, Ma DW, Serhan CN, Bazinet RP: Unesterified docosahexaenoic acid is protective in neuroinflammation. J Neurochem 2013, 127:378-393.