Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China.
Tianjin Key Laboratory of Artificial Cell, Tianjin Institute of Hepatobiliary Disease, The Third Affiliated Hospital of Nankai University, Tianjin, China.
Horm Metab Res. 2020 Jul;52(7):532-539. doi: 10.1055/a-1157-0166. Epub 2020 May 6.
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 () 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 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.
尽管胰高血糖素样肽-1（GLP-1）类似物已被报道可抑制非酒精性脂肪性肝病（NAFLD）中的氧化应激，但目前尚无有效的 NAFLD 治疗药物。因此，在本研究中，我们旨在研究 GLP-1 类似物利拉鲁肽对 HepG2 细胞中脂毒性诱导的氧化应激的保护作用，并阐明其潜在机制。将 HepG2 细胞培养 48 小时，并分别用游离脂肪酸（FFA）混合物、FFA 混合物和利拉鲁肽或 FFA 混合物、利拉鲁肽和 exendin（9-39）处理。用油红 O 染色法检测脂滴积累。通过使用 2'，7'-二氯荧光素二乙酸酯和硫代巴比妥酸反应性物质测量细胞内活性氧（ROS）水平来评估氧化应激，而通过测量超氧化物歧化酶和过氧化氢酶的活性来评估抗氧化能力。使用定量 RT-PCR 分析核因子红细胞 2 相关因子 2（NRF2）基因和编码抗氧化酶的基因的表达。使用免疫荧光细胞染色和 Western blot 评估细胞和核 NRF2 表达水平。利拉鲁肽处理可减少高脂肪诱导的脂质形成和氧化应激标志物水平，并增加 HepG2 细胞中的抗氧化酶活性。利拉鲁肽处理可增加 NRF2 靶基因的 mRNA 表达，诱导 NRF2 核易位，并增加核 NRF2 水平，而不改变 Nrf2 基因的 mRNA 表达。总之，这些结果表明，利拉鲁肽对脂毒性诱导的氧化应激具有保护作用，可能通过调节肝细胞中的 NRF2 和抗氧化酶的表达。
