Glycine enhances expression of adiponectin and IL-10 in 3T3-L1 adipocytes without affecting adipogenesis and lipolysis
- 346 Downloads
Glycine supplementation has been reported to enhance white-fat loss and improve sensitivity to insulin in animals with obesity or type 2 diabetes. However, the underlying mechanisms responsible for the beneficial effects of glycine remain largely unknown. The purpose of this study was to test the hypothesis that glycine regulates adipocyte differentiation, adipogenesis, and lipolysis, therefore, contributing to white-fat reduction. 3T3-L1 pre-adipocytes were induced to differentiate into adipocytes in the presence of glycine (0, 0.25, 1.0, and 2.0 mmol/L) or resveratrol (50 or 100 μmol/L, served as a positive control) during the differentiation process. Hela and HepG2 cells cultured with oleic acid to induce lipid accumulation in the presence of glycine (0, 1.0, and 2.0 mmol/L) or 10 μmol/L isoproterenol (served as a positive control) for 24 h. Intracellular lipid accumulation, intracellular triglycerides, lipid droplets’ diameters of mature adipocytes, mRNA, and protein levels of genes involved in the adipogenesis and lipolysis were analyzed. Isobutylxanthine–dexamethasone–insulin (MDI)-induced adipogenesis in 3T3-L1 cells were blocked by resveratrol, but not by glycine, as shown by decreased lipid contents, reduced diameters of lipid droplets, decreased protein abundances for peroxisome proliferator-activated receptor γ (PPARγ), CCAAT-enhancer-binding protein α (C/EBPα), as well as increased protein abundance of peroxisome proliferator-activated receptor coactivator-1α (PGC-1α), critical transcriptional factors that regulates adipogenesis. However, the mRNA levels of adiponectin and interleukin-10 (IL-10), two adipose-derived adipocytokines with anti-inflammatory effects, were greatly enhanced (P < 0.05) by 2 mmol/L glycine. Compared with non-treated controls, 10 μmol/L isoproterenol significantly decreased (P < 0.05) the intracellular lipid and triglyceride contents induced by oleic acid in Hela and HepG2 cells. mRNA level of fatty acid synthase (FASN), a gene involved in fatty acid synthesis, was significantly reduced (P < 0.05), while that for ATGL (adipose triglyceride lipase) and HSL (hormone-sensitive lipase), genes involved in lipolysis were significantly enhanced (P < 0.05) by isoproterenol. However, oleic acid induced the accumulation of intracellular triglyceride and lipid contents were not affected by glycine. In conclusion, glycine exposure enhanced the mRNA levels of adipose-derived adiponectin and IL-10 without affecting adipogenesis and lipolysis in 3T3-L1 adipocytes. These findings provide a possible explanation for the anti-obesity and anti-diabetic effects of glycine that were previously reported in animal models. More studies are needed to uncover the underlying mechanisms responsible for this regulatory effect of glycine on anti-inflammatory adipocytokines expression in both in vitro and in vivo models.
KeywordsGlycine Differentiation Adipogenesis Lipolysis 3T3-L1 Adipocytokine
Fatty acid synthase
Adipose triglyceride lipase
Peroxisome proliferator-activated receptor γ
Peroxisome proliferator-activated receptor coactivator-1α
CCAAT-enhancer-binding protein α
This work was supported by the Grants from National Basic Research Program of China (No. 2013CB127302), the National Natural Science Foundation of China (No. 31572410, 31272451, 31272450), Chinese University Scientific Fund (2015DK001), the 111 Project (B16044), the Program for New Century Excellent Talents in University (NCET-12-0522), the Agriculture and Food Research Initiative Competitive Grant from the USDA National Institute of Food and Agriculture (No. 2014-67015-21770), and Texas A&M AgriLife Research (H-8200).
Compliance with ethical standards
Conflict of interest
The authors declare that there are no conflicts of interest associated with the manuscript.
This article does not contain any studies with human participants or animals performed by any other authors.
- Alarcon-Aguilar FJ, Almanza-Perez J, Blancas G, Angeles S, Garcia-Macedo R, Roman R, Cruz M (2008) Glycine regulates the production of pro-inflammatory cytokines in lean and monosodium glutamate-obese mice. Eur J Pharmacol 599(1–3):152–158. https://doi.org/10.1016/j.ejphar.2008.09.047 CrossRefPubMedGoogle Scholar
- Blancas-Flores G, Alarcon-Aguilar FJ, Garcia-Macedo R, Almanza-Perez JC, Flores-Saenz JL, Roman-Ramos R, Ventura-Gallegos JL, Kumate J, Zentella-Dehesa A, Cruz M (2012) Glycine suppresses TNF-alpha-induced activation of NF-kappaB in differentiated 3T3-L1 adipocytes. Eur J Pharmacol 689(1–3):270–277. https://doi.org/10.1016/j.ejphar.2012.06.025 CrossRefPubMedGoogle Scholar
- Cohen P, Levy JD, Zhang Y, Frontini A, Kolodin DP, Svensson KJ, Lo JC, Zeng X, Ye L, Khandekar MJ, Wu J, Gunawardana SC, Banks AS, Camporez JP, Jurczak MJ, Kajimura S, Piston DW, Mathis D, Cinti S, Shulman GI, Seale P, Spiegelman BM (2014) Ablation of PRDM16 and beige adipose causes metabolic dysfunction and a subcutaneous to visceral fat switch. Cell 156(1–2):304–316. https://doi.org/10.1016/j.cell.2013.12.021 CrossRefPubMedPubMedCentralGoogle Scholar
- Duncan RE, Ahmadian M, Jaworski K, Sarkadi-Nagy E, Sul HS (2007) Regulation of lipolysis in adipocytes. Annu Rev Nutr 27:79–101. https://doi.org/10.1146/annurev.nutr.27.061406.093734 CrossRefPubMedPubMedCentralGoogle Scholar
- El Hafidi M, Perez I, Zamora J, Soto V, Carvajal-Sandoval G, Banos G (2004) Glycine intake decreases plasma free fatty acids, adipose cell size, and blood pressure in sucrose-fed rats. Am J Physiol Regul Integr Comp Physiol 287(6):R1387–R1393. https://doi.org/10.1152/ajpregu.00159.2004 CrossRefPubMedGoogle Scholar
- Garcia-Macedo R, Sanchez-Munoz F, Almanza-Perez JC, Duran-Reyes G, Alarcon-Aguilar F, Cruz M (2008) Glycine increases mRNA adiponectin and diminishes pro-inflammatory adipokines expression in 3T3-L1 cells. Eur J Pharmacol 587(1–3):317–321. https://doi.org/10.1016/j.ejphar.2008.03.051 CrossRefPubMedGoogle Scholar
- Hotta K, Funahashi T, Bodkin NL, Ortmeyer HK, Arita Y, Hansen BC, Matsuzawa Y (2001) Circulating concentrations of the adipocyte protein adiponectin are decreased in parallel with reduced insulin sensitivity during the progression to type 2 diabetes in rhesus monkeys. Diabetes 50(5):1126–1133. https://doi.org/10.2337/diabetes.50.5.1126 CrossRefPubMedGoogle Scholar
- Linhart HG, Ishimura-Oka K, DeMayo F, Kibe T, Repka D, Poindexter B, Bick RJ, Darlington GJ (2001) C/EBPalpha is required for differentiation of white, but not brown, adipose tissue. Proc Natl Acad Sci USA 98(22):12532–12537. https://doi.org/10.1073/pnas.211416898 CrossRefPubMedPubMedCentralGoogle Scholar
- Newgard CB, An J, Bain JR, Muehlbauer MJ, Stevens RD, Lien LF, Haqq AM, Shah SH, Arlotto M, Slentz CA, Rochon J, Gallup D, Ilkayeva O, Wenner BR, Yancy WS, Eisenson H, Musante G, Surwit R, Millington DS, Butler MD, Svetkey LP (2009) A branched-chain amino acid-related metabolic signature that differentiates obese and lean humans and contributes to insulin resistance (vol 9, pg 311. Cell Metab 9(6):565–566. https://doi.org/10.1016/j.cmet.2009.05.001 CrossRefGoogle Scholar
- Rosse RB, Theut SK, Banayschwartz M, Leighton M, Scarcella E, Cohen CG, Deutsch SI (1989) Glycine adjuvant therapy to conventional neuroleptic treatment in schizophrenia—an open-label. Pilot-Study. Clinical Neuropharmacology 12(5):416–424. https://doi.org/10.1097/00002826-198910000-00006 CrossRefPubMedGoogle Scholar
- Sandoval GC, Santillan RM, Juarez E, Martinez GR, Juarez MEC (1999) Effect of glycine on hemoglobin glycation in diabetic patients. Proc Forty Second Annu Meet West Pharmacol Soc 42:31–32Google Scholar
- Shan T, Xiong Y, Zhang P, Li Z, Jiang Q, Bi P, Yue F, Yang G, Wang Y, Liu X, Kuang S (2016) Lkb1 controls brown adipose tissue growth and thermogenesis by regulating the intracellular localization of CRTC3. Nat Commun 7:12205. https://doi.org/10.1038/ncomms12205 CrossRefPubMedPubMedCentralGoogle Scholar
- Spittler A, Reissner CM, Oehler R, Gornikiewicz A, Gruenberger T, Manhart N, Brodowicz T, Mittlboeck M, Boltz-Nitulescu G, Roth E (1999) Immunomodulatory effects of glycine on LPS-treated monocytes: reduced TNF-alpha production and accelerated IL-10 expression. FASEB J 13(3):563–571CrossRefPubMedGoogle Scholar
- Stoffels B, Turler A, Schmidt J, Nazir A, Tsukamoto T, Moore BA, Schnurr C, Kalff JC, Bauer AJ (2011) Anti-inflammatory role of glycine in reducing rodent postoperative inflammatory ileus. Neurogastroenterol Motil 23(1):76–87. https://doi.org/10.1111/j.1365-2982.2010.01603.x (e78) CrossRefPubMedGoogle Scholar
- Takashina C, Tsujino I, Watanabe T, Sakaue S, Ikeda D, Yamada A, Sato T, Ohira H, Otsuka Y, Oyama-Manabe N, Ito YM, Nishimura M (2016) Associations among the plasma amino acid profile, obesity, and glucose metabolism in Japanese adults with normal glucose tolerance. Nutr Metab 13:5. https://doi.org/10.1186/s12986-015-0059-5 CrossRefGoogle Scholar
- Weyer C, Funahashi T, Tanaka S, Hotta K, Matsuzawa Y, Pratley RE, Tataranni PA (2001) Hypoadiponectinemia in obesity and type 2 diabetes: close association with insulin resistance and hyperinsulinemia. J Clin Endocrinol Metab 86(5):1930–1935. https://doi.org/10.1210/jcem.86.5.7463 CrossRefPubMedGoogle Scholar
- Zhong Z, Wheeler MD, Li X, Froh M, Schemmer P, Yin M, Bunzendaul H, Bradford B, Lemasters JJ (2003) l-Glycine: a novel antiinflammatory, immunomodulatory, and cytoprotective agent. Curr Opin Clin Nutr Metab Care 6(2):229–240. https://doi.org/10.1097/01.mco.0000058609.19236.a4 CrossRefPubMedGoogle Scholar