Liraglutide Ameliorates Lipotoxicity-Induced Oxidative Stress by
                    Activating the NRF2 Pathway in HepG2 Cells

Chong-gui Zhu; Ying Luo; Hao Wang; Jun-Yi Li; Jie Yang; Ya-xin Liu; Hui-qi Qu; Bao-li Wang; Mei Zhu

doi:10.1055/a-1157-0166

Hormone and Metabolic Research, Inhaltsverzeichnis

Horm Metab Res 2020; 52(07): 532-539
DOI: 10.1055/a-1157-0166

Endocrine Research

Liraglutide Ameliorates Lipotoxicity-Induced Oxidative Stress by Activating the NRF2 Pathway in HepG2 Cells

Authors

Chong-gui Zhu‡

¹Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
Ying Luo‡

²Tianjin Key Laboratory of Artificial Cell, Tianjin Institute of Hepatobiliary Disease, The Third Affiliated Hospital of Nankai University, Tianjin, China
Hao Wang‡

¹Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
Jun-Yi Li

³Department of Cell Biology, Tianjin Medical University, Tianjin, China
Jie Yang

³Department of Cell Biology, Tianjin Medical University, Tianjin, China
Ya-xin Liu

¹Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
Hui-qi Qu

⁴Center for Applied Genomics, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
Bao-li Wang

⁵Key Lab of Hormones and Development (Ministry of Health), Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
Mei Zhu

¹Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China

Abstract

Although glucagon-like peptide-1 (GLP-1) analogue has been reported to suppress oxidative stress in non-alcoholic fatty liver disease (NAFLD), an effective therapeutic agent for NAFLD is currently unavailable. Therefore, in this study, we aimed to investigate the protective effects of the GLP-1 analogue liraglutide against lipotoxicity-induced oxidative stress in HepG2 cells and to elucidate the underlying mechanisms. HepG2 cells were cultured for 48 hours and treated with a free fatty acid (FFA) mixture: FFA mixture and liraglutide or FFA mixture, liraglutide, and exendin (9–39). Lipid accumulation was examined by oil red O staining. Oxidative stress was assessed by measuring the levels of intracellular reactive oxygen species using 2′,7′-dichlorofluorescein diacetate and thiobarbituric acid-reactive substances, whereas antioxidant capacity was assessed by measuring the activity of superoxide dismutase and catalase. Expression of the nuclear factor erythroid-2-related factor 2 (NRF2) gene and the genes encoding antioxidant enzymes was analyzed using quantitative RT-PCR. Cellular and nuclear NRF2 expression levels were assessed using immunofluorescence cell staining and western blotting. Liraglutide treatment reduced high fat-induced lipid formation and the levels of oxidative stress markers and increased antioxidant enzyme activity in HepG2 cells. Liraglutide treatment increased the mRNA expression of NRF2 target genes, induced NRF2 nuclear translocation, and increased nuclear NRF2 levels without altering NRF2 mRNA expression. Collectively, these results indicate that liraglutide exhibits a protective effect against lipotoxicity-induced oxidative stress, possibly via modulation of NRF2 and expression of antioxidant enzymes in liver cells.

Key words

GLP-1 analogues - antioxidant enzymes - NRF2 - NAFLD

Volltext

Referenzen

References
1 Rinella ME. Nonalcoholic fatty liver disease: a systematic review. JAMA 2015; 313: 2263-2273
2 Du J, Zhang M, Lu J. et al. Osteocalcin improves nonalcoholic fatty liver disease in mice through activation of Nrf2 and inhibition of JNK. Endocrine 2016; 53: 701-709
3 Qiang X, Xu L, Zhang M. et al. Demethyleneberberine attenuates non-alcoholic fatty liver disease with activation of AMPK and inhibition of oxidative stress. Biochem Biophys Res Commun 2016; 472: 603-609
4 Qu LL, Yu B, Li Z. et al. Gastrodin ameliorates oxidative stress and proinflammatory response in nonalcoholic fatty liver disease through the AMPK/Nrf2 pathway. Phytother Res 2016; 30: 402-411
5 Tang W, Jiang YF, Ponnusamy M. et al. Role of Nrf2 in chronic liver disease. World J Gastroenterol 2014; 20: 13079-13087
6 Chowdhry S, Nazmy MH, Meakin PJ. et al. Loss of Nrf2 markedly exacerbates nonalcoholic steatohepatitis. Free Radic Biol Med 2010; 48: 357-371
7 Drucker DJ, Sherman SI, Gorelick FS. et al. Incretin-based therapies for the treatment of type 2 diabetes: evaluation of the risks and benefits. Diabetes Care 2010; 33: 428-433
8 Armstrong MJ, Houlihan DD, Rowe IA. et al. Safety and efficacy of liraglutide in patients with type 2 diabetes and elevated liver enzymes: individual patient data meta-analysis of the LEAD program. Aliment Pharmacol Ther 2013; 37: 234-242
9 Oh YS, Jun HS. Effects of glucagon-like peptide-1 on oxidative stress and Nrf2 signaling. Int J Mol Sci 2017; 19: 26
10 Svegliati-Baroni G, Saccomanno S, Rychlicki C. et al. Glucagon-like peptide-1 receptor activation stimulates hepatic lipid oxidation and restores hepatic signalling alteration induced by a high-fat diet in nonalcoholic steatohepatitis. Liver Int 2011; 31: 1285-1297
11 Zhang L, Yang M, Ren H. et al. GLP-1 analogue prevents NAFLD in ApoE KO mice with diet and Acrp30 knockdown by inhibiting c-JNK. Liver Int 2013; 33: 794-804
12 Guo J, Li C, Yang C. et al. Liraglutide reduces hepatic glucolipotoxicity-induced liver cell apoptosis through NRF2 signaling in Zucker diabetic fatty rats. Mol Med Rep 2018; 17: 8316-8324
13 Zhang WY, Hu XF, Wan N. et al. Protective effect of the glucagon-like peptide-1 analogue liraglutide on carbon tetrachloride-induced acute liver injury in mice. Biochem Biophys Res Commun 2019; 514: 386-392
14 Feldstein AE, Werneburg NW, Canbay A. et al. Free fatty acids promote hepatic lipotoxicity by stimulating TNF-α expression via a lysosomal pathway. Hepatology 2004; 40: 185-194
15 Day CP, James OF. Hepatic steatosis: innocent bystander or guilty party?. Hepatology 1998; 27: 1463-1466
16 Peverill W, Powell LW, Skoien R. Evolving concepts in the pathogenesis of NASH: beyond steatosis and inflammation. Int J Mol Sci 2014; 15: 8591-8638
17 Nassir F, Ibdah JA.. Role of mitochondria in nonalcoholic fatty liver disease. Int J Mol Sci 2014; 15: 8713-8742
18 Ricchi M, Odoardi MR, Carulli L. et al. Differential effect of oleic and palmitic acid on lipid accumulation and apoptosis in cultured hepatocytes. J Gastroenterol Hepatol 2009; 24: 830-840
19 Moravcova A, Cervinkova Z, Kucera O. et al. The effect of oleic and palmitic acid on induction of steatosis and cytotoxicity on rat hepatocytes in primary culture. Physiol Res 2015; 64: S627-S636
20 Liu Y, Wei R, Hong TP.. Potential roles of glucagon-like peptide-1-based therapies in treating non-alcoholic fatty liver disease. World J Gastroenterol 2014; 20: 9090-9097
21 Yoo J, Cho IJ, Jeong IK. et al. Exendin-4, a glucagon-like peptide-1 receptor agonist, reduces hepatic steatosis and endoplasmic reticulum stress by inducing nuclear factor erythroid-derived 2-related factor 2 nuclear translocation. Toxicol Appl Pharmacol 2018; 360: 18-29
22 Ao N, Yang J, Du J. Effect and mechanism of liraglutide on the apoptosis of human hepatocellular carcinoma HepG2 cells induced with palmitic acid. Zhonghua Gan Zang Bing Za Zhi 2019; 27: 445-449
23 Yang SH, Xu RX, Cui CJ. et al. Liraglutide downregulates hepatic LDL receptor and PCSK9 expression in HepG2 cells and db/db mice through a HNF-1a dependent mechanism. Cardiovasc Diabetol 2018; 17: 48
24 Ao N, Yang J, Wang X. et al. Glucagon-like peptide-1 preserves non-alcoholic fatty liver disease through inhibition of the endoplasmic reticulum stress-associated pathway. Hepatol Res 2016; 46: 343-353
25 Dhanesha N, Joharapurkar A, Shah G. et al. Exendin-4 reduces glycemia by increasing liver glucokinase activity: an insulin independent effect. Pharmacol Rep 2012; 64: 140-149
26 Liu J, Yang K, Xiao W. et al. GLP-1 receptor agonists stimulate ANGPTL8 production through the PI3K/Akt pathway in a GLP-1 receptor-dependent manner. Peptides 2018; 106: 83-90
27 Sharma S, Mells JE, Fu PP. et al. GLP-1 analogs reduce hepatocyte steatosis and improve survival by enhancing the unfolded protein response and promoting macroautophagy. PloS One 2011; 6: e25269
28 Lee YS, Shin S, Shigihara T. et al. Glucagon-like peptide-1 gene therapy in obese diabetic mice results in long-term cure of diabetes by improving insulin sensitivity and reducing hepatic gluconeogenesis. Diabetes 2007; 56: 1671-1679
29 Ding X, Saxena NK, Lin S. et al. Exendin-4, a glucagon-like protein-1 (GLP-1) receptor agonist, reverses hepatic steatosis in ob/ob mice. Hepatology 2006; 43: 173-181
30 Fontana J, Kučera O, Anděl M. et al. Effect of glucagon-like peptide-1 analogue liraglutide on primary cultures of rat hepatocytes isolated from lean and steatotic livers. Gen Physiol Biophys 2019; 38: 343-352
31 Meakin PJ, Chowdhry S, Sharma RS. et al. Susceptibility of Nrf2-null mice to steatohepatitis and cirrhosis upon consumption of a high-fat diet is associated with oxidative stress, perturbation of the unfolded protein response, and disturbance in the expression of metabolic enzymes but not with insulin resistance. Mol Cell Biol 2014; 34: 3305-3320
32 Nakai K, Fujii H, Kono K. et al. Vitamin D activates the Nrf2-Keap1 antioxidant pathway and ameliorates nephropathy in diabetic rats. Am J Hypertens 2014; 27: 586-595
33 Valdecantos MP, Prieto-Hontoria PL, Pardo V. et al. Essential role of Nrf2 in the protective effect of lipoic acid against lipoapoptosis in hepatocytes. Free Radic Biol Med 2015; 84: 263-278
34 Fernandez-Millan E, Martin MA, Goya L. et al. Glucagon-like peptide-1 improves beta-cell antioxidant capacity via extracellular regulated kinases pathway and Nrf2 translocation. Free Radic Biol Med 2016; 95: 16-26
35 Deng C, Cao J, Han J. et al. Liraglutide activates the Nrf2/HO-1 antioxidant pathway and protects brain nerve cells against cerebral ischemia in diabetic rats. Comput Intell Neurosci 2018; 3094504