Activation of Notch signaling pathologically enhances lipogenesis and gluconeogenesis in the liver causing non-alcoholic fatty liver disease (NAFLD) and diabetes. Delta-like 1 homolog (DLK1), an imprinted gene that can modulate adipogenesis and muscle development in mice, was found as an inhibitory regulator of Notch signaling. Therefore, we investigated the metabolic effect of exogenous DLK1 in vitro and in vivo.
A soluble DLK1 peptide was generated with fusion between a human Fc fragment and extracellular domain of DLK1. Male db/db mice were randomly assigned to two groups: vehicle treated and DLK1-treated group (25 mg kg−1, intraperitoneal injection, twice a week for 4 weeks). Primary mice hepatocytes and HepG2 cells were used for in vitro experiments.
After 4 weeks of DLK1 administration, hepatic triglyceride content and lipid droplets in liver tissues, as well as serum levels of liver enzymes, were markedly decreased in db/db mice. DLK1 treatment induced phosphorylation of AMPK and ACC and suppressed nuclear expression of SREBP-1c in the mouse liver or hepatocytes, indicating regulation of fatty acid oxidation and synthesis pathways. Furthermore, DLK1-treated mice showed significantly lower levels of fasting and random glucose, with improved glucose and insulin tolerance compared with the vehicle-treated group. Macrophage infiltration and proinflammatory cytokine levels in the epididymal fat were decreased in DLK1-treated db/db mice. Moreover, DLK1 suppressed glucose production from hepatocytes, which was blocked after co-administration of an AMPK inhibitor, compound C. DLK1-treated hepatocytes and mouse liver tissues showed lower PEPCK and G6Pase expression. DLK1 triggered AKT phosphorylation followed by cytosolic translocation of FOXO1 from the nucleus in hepatocytes.
The present study demonstrated that exogenous administration of DLK1 reduced hepatic steatosis and hyperglycemia via AMPK activation in the liver. This result suggests that DLK1 may be a novel therapeutic approach for treating NAFLD and diabetes.
Subscribe to Journal
Get full journal access for 1 year
only $64.42 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Wang YC, McPherson K, Marsh T, Gortmaker SL, Brown M . Health and economic burden of the projected obesity trends in the USA and the UK. Lancet 2011; 378: 815–825.
Kopan R, Ilagan MX . The canonical Notch signaling pathway: unfolding the activation mechanism. Cell 2009; 137: 216–233.
Bolos V, Grego-Bessa J, de la Pompa JL . Notch signaling in development and cancer. Endocr Rev 2007; 28: 339–363.
Ntziachristos P, Lim JS, Sage J, Aifantis I . From fly wings to targeted cancer therapies: a centennial for notch signaling. Cancer Cell 2014; 25: 318–334.
Pajvani UB, Shawber CJ, Samuel VT, Birkenfeld AL, Shulman GI, Kitajewski J et al. Inhibition of Notch signaling ameliorates insulin resistance in a FoxO1-dependent manner. Nat Med 2011; 17: 961–967.
Pajvani UB, Qiang L, Kangsamaksin T, Kitajewski J, Ginsberg HN, Accili D . Inhibition of Notch uncouples Akt activation from hepatic lipid accumulation by decreasing mTorc1 stability. Nat Med 2013; 19: 1054–1060.
Valenti L, Mendoza RM, Rametta R, Maggioni M, Kitajewski C, Shawber CJ et al. Hepatic notch signaling correlates with insulin resistance and nonalcoholic fatty liver disease. Diabetes 2013; 62: 4052–4062.
Dufraine J, Funahashi Y, Kitajewski J . Notch signaling regulates tumor angiogenesis by diverse mechanisms. Oncogene 2008; 27: 5132–5137.
Lai EC . Notch signaling: control of cell communication and cell fate. Development 2004; 131: 965–973.
Baladron V, Ruiz-Hidalgo MJ, Nueda ML, Diaz-Guerra MJ, Garcia-Ramirez JJ, Bonvini E et al. dlk acts as a negative regulator of Notch1 activation through interactions with specific EGF-like repeats. Exp Cell Res 2005; 303: 343–359.
Nueda ML, Baladron V, Sanchez-Solana B, Ballesteros MA, Laborda J . The EGF-like protein dlk1 inhibits notch signaling and potentiates adipogenesis of mesenchymal cells. J Mol Biol 2007; 367: 1281–1293.
Bray SJ, Takada S, Harrison E, Shen SC, Ferguson-Smith AC . The atypical mammalian ligand Delta-like homologue 1 (Dlk1) can regulate Notch signalling in Drosophila. BMC Dev Biol 2008; 8: 11.
Wang Y, Sul HS . Ectodomain shedding of preadipocyte factor 1 (Pref-1) by tumor necrosis factor alpha converting enzyme (TACE) and inhibition of adipocyte differentiation. Mol Cell Biol 2006; 26: 5421–5435.
Backliwal G, Hildinger M, Chenuet S, Wulhfard S, De Jesus M, Wurm FM . Rational vector design and multi-pathway modulation of HEK 293E cells yield recombinant antibody titers exceeding 1 g/l by transient transfection under serum-free conditions. Nucleic Acids Res 2008; 36: e96.
Seglen PO . Hepatocyte suspensions and cultures as tools in experimental carcinogenesis. J Toxicol Environ Health 1979; 5: 551–560.
Lee YH, Kim SH, Lee YJ, Kang ES, Lee BW, Cha BS et al. Transcription factor Snail is a novel regulator of adipocyte differentiation via inhibiting the expression of peroxisome proliferator-activated receptor gamma. Cell Mol Life Sci 2013; 70: 3959–3971.
Gesina E, Tronche F, Herrera P, Duchene B, Tales W, Czernichow P et al. Dissecting the role of glucocorticoids on pancreas development. Diabetes 2004; 53: 2322–2329.
Pernicova I, Korbonits M . Metformin—mode of action and clinical implications for diabetes and cancer. Nat Rev Endocrinol 2014; 10: 143–156.
Ben-Shlomo S, Zvibel I, Shnell M, Shlomai A, Chepurko E, Halpern Z et al. Glucagon-like peptide-1 reduces hepatic lipogenesis via activation of AMP-activated protein kinase. J Hepatol 2011; 54: 1214–1223.
Zhang BB, Zhou G, Li C . AMPK: an emerging drug target for diabetes and the metabolic syndrome. Cell Metab 2009; 9: 407–416.
Puigserver P, Rhee J, Donovan J, Walkey CJ, Yoon JC, Oriente F et al. Insulin-regulated hepatic gluconeogenesis through FOXO1-PGC-1alpha interaction. Nature 2003; 423: 550–555.
Smas CM, Sul HS . Pref-1, a protein containing EGF-like repeats, inhibits adipocyte differentiation. Cell 1993; 73: 725–734.
Wang Y, Kim KA, Kim JH, Sul HS . Pref-1, a preadipocyte secreted factor that inhibits adipogenesis. J Nutr 2006; 136: 2953–2956.
Sul HS . Minireview: Pref-1: role in adipogenesis and mesenchymal cell fate. Mol Endocrinol 2009; 23: 1717–1725.
Moon YS, Smas CM, Lee K, Villena JA, Kim KH, Yun EJ et al. Mice lacking paternally expressed Pref-1/Dlk1 display growth retardation and accelerated adiposity. Mol Cell Biol 2002; 22: 5585–5592.
Villena JA, Choi CS, Wang Y, Kim S, Hwang YJ, Kim YB et al. Resistance to high-fat diet-induced obesity but exacerbated insulin resistance in mice overexpressing preadipocyte factor-1 (Pref-1): a new model of partial lipodystrophy. Diabetes 2008; 57: 3258–3266.
Lee K, Villena JA, Moon YS, Kim KH, Lee S, Kang C et al. Inhibition of adipogenesis and development of glucose intolerance by soluble preadipocyte factor-1 (Pref-1). J Clin Invest 2003; 111: 453–461.
Ferron SR, Charalambous M, Radford E, McEwen K, Wildner H, Hind E et al. Postnatal loss of Dlk1 imprinting in stem cells and niche astrocytes regulates neurogenesis. Nature 2011; 475: 381–385.
da Rocha ST, Charalambous M, Lin S, Gutteridge I, Ito Y, Gray D et al. Gene dosage effects of the imprinted delta-like homologue 1 (dlk1/pref1) in development: implications for the evolution of imprinting. PLOS Genet 2009; 5: e1000392.
Mortensen SB, Jensen CH, Schneider M, Thomassen M, Kruse TA, Laborda J et al. Membrane-tethered delta-like 1 homolog (DLK1) restricts adipose tissue size by inhibiting preadipocyte proliferation. Diabetes 2012; 61: 2814–2822.
Charalambous M, Da Rocha ST, Radford EJ, Medina-Gomez G, Curran S, Pinnock SB et al. DLK1/PREF1 regulates nutrient metabolism and protects from steatosis. Proc Natl Acad Sci USA 2014; 111: 16088–16093.
Hardie DG, Ross FA, Hawley SA . AMPK: a nutrient and energy sensor that maintains energy homeostasis. Nat Rev Mol Cell Biol 2012; 13: 251–262.
Falix FA, Aronson DC, Lamers WH, Gaemers IC . Possible roles of DLK1 in the Notch pathway during development and disease. Biochim Biophys Acta 2012; 1822: 988–995.
Huang CC, Chuang JH, Huang LL, Chou MH, Wu CL, Chen CM et al. The human Delta-like 1 homologue is implicated in the progression of liver fibrosis in biliary atresia. J Pathol 2004; 202: 172–179.
Zhu NL, Asahina K, Wang J, Ueno A, Lazaro R, Miyaoka Y et al. Hepatic stellate cell-derived delta-like homolog 1 (DLK1) protein in liver regeneration. J Biol Chem 2012; 287: 10355–10367.
Labialle S, Marty V, Bortolin-Cavaille ML, Hoareau-Osman M, Pradere JP, Valet P et al. The miR-379/miR-410 cluster at the imprinted Dlk1-Dio3 domain controls neonatal metabolic adaptation. EMBO J 2014; 33: 2216–2230.
Li P, daY Oh, Bandyopadhyay G, Lagakos WS, Talukdar S, Osborn O et al. LTB4 promotes insulin resistance in obese mice by acting on macrophages, hepatocytes and myocytes. Nat Med 2015; 21: 239–247.
Seo YY, Cho YK, Bae JC, Seo MH, Park SE, Rhee EJ et al. Tumor necrosis factor-alpha as a predictor for the development of nonalcoholic fatty liver disease: a 4-year follow-up study. Endocrinol Metab (Seoul) 2013; 28: 41–45.
Utzschneider KM, Kahn SE . Review: the role of insulin resistance in nonalcoholic fatty liver disease. J Clin Endocrinol Metab 2006; 91: 4753–4761.
This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2012R1A1A2043812). The authors would like to thank Dong-Su Jang, MFA, (Medical Illustrator, Medical Research Support Section, Yonsei University College of Medicine, Seoul, Korea) for his help with the illustrations.
Y.-h.L., and B.-S.C. designed research; Y.L., M.R.Y., H.M.K., B.H.J. and B.-C.P. performed research; B.-C.P. and Y.W.P. contributed materials/analytic tools; Y.-h.L., M.R.Y., B.-W.L. and E.S.K. analyzed data; B.-W.L., E.S.K. and H.C.L. provided critical revision of the article for important intellectual content; and Y.L., H.C.L. and B.-S.C. wrote the paper.
The authors declare no conflict of interest.
Supplementary Information accompanies this paper on International Journal of Obesity website
About this article
Cite this article
Lee, Y., Yun, M., Kim, H. et al. Exogenous administration of DLK1 ameliorates hepatic steatosis and regulates gluconeogenesis via activation of AMPK. Int J Obes 40, 356–365 (2016). https://doi.org/10.1038/ijo.2015.173
Stem Cell Research & Therapy (2019)
Archives of Endocrinology and Metabolism (2019)
Treatment of Diabetic Mice with a Combination of Ketogenic Diet and Aerobic Exercise via Modulations of PPARs Gene Programs
PPAR Research (2018)
Cell Metabolism (2018)
Journal of Biological Chemistry (2018)