Department of Genetic, North Tehran Branch, Islamic Azad University, Tehran, 1651153311, Iran.
Department of Genetic, North Tehran Branch, Islamic Azad University, Tehran, 1651153311, Iran; Department of Cell and Molecular Biology, Faculty of Biological Science, Kharazmi University, Tehran, 1571914911, Iran.
Eur J Pharmacol. 2023 Mar 5;942:175536. doi: 10.1016/j.ejphar.2023.175536. Epub 2023 Jan 21.
Non-alcoholic steatohepatitis (NASH) is associated with intrahepatic lipid accumulation, inflammation, and hepatocyte death. Several studies have indicated that high-fat diets increase ceramide synthases-6 (CerS-6) expression and a concomitant elevation of C16-ceramides, which can modulate endoplasmic reticulum (ER) stress and further contribute to the progression of NASH. Ceramide levels have reportedly been impacted by basic fibroblast growth factor (bFGF) in various diseases. This study looked into the role of bFGF on CerS6/C16-ceramide and ER stress-related pathways in a mouse model of NASH. Male C57BL/6J mice were fed a western diet (WD) combined with carbon tetrachloride (CCl4) for eight weeks. Next, bFGF was injected into the NASH mice for seven days of continuous treatment. The effects of bFGF on NASH endpoints (including steatosis, inflammation, ballooning, and fibrosis), ceramide levels and ER-stress-induced inflammation, reactive oxygen species (ROS) production, and apoptosis were evaluated. Treatment with bFGF significantly reduced CerS-6/C16-ceramide. Further, the inflammatory condition was alleviated with reduction of nuclear factor-kappa B (NF-κB), tumor necrosis factor-alpha (TNF-α), and interleukin 6 (IL-6) gene expression. ROS level was also reduced. ER stress-related cell death diminished by reducing C/EBP homologous protein (CHOP) mRNA expression and caspase 3 activity. Furthermore, activation of the hepatic stellate cells was inhibited in the bFGF-treated mice by lowering the amount of alpha-smooth muscle actin (α-SMA) at the mRNA and protein level. According to our findings, CerS-6/C16-ceramide alteration impacts ER stress-mediated inflammation, oxidative stress, and apoptosis. The bFGF treatment effectively attenuated the development of NASH by downregulating CerS-6/C16-ceramide and subsequent ER stress-related pathways.
非酒精性脂肪性肝炎(NASH)与肝内脂质积聚、炎症和肝细胞死亡有关。多项研究表明,高脂肪饮食会增加神经酰胺合酶 6(CerS-6)的表达,并使 C16-神经酰胺水平升高,这可以调节内质网(ER)应激,进一步促进 NASH 的进展。据报道,碱性成纤维细胞生长因子(bFGF)在各种疾病中会影响神经酰胺水平。本研究探讨了 bFGF 在 NASH 小鼠模型中对 CerS6/C16-神经酰胺和 ER 应激相关通路的作用。雄性 C57BL/6J 小鼠喂食西方饮食(WD)并联合四氯化碳(CCl4)8 周。然后,bFGF 被注射到 NASH 小鼠中进行连续 7 天的治疗。评估 bFGF 对 NASH 终点(包括脂肪变性、炎症、气球样变和纤维化)、神经酰胺水平以及 ER 应激诱导的炎症、活性氧(ROS)产生和细胞凋亡的影响。bFGF 治疗可显著降低 CerS-6/C16-神经酰胺水平。此外,通过降低核因子-kappa B(NF-κB)、肿瘤坏死因子-α(TNF-α)和白细胞介素 6(IL-6)基因表达,减轻了炎症状态。ROS 水平也降低了。通过降低 C/EBP 同源蛋白(CHOP)mRNA 表达和半胱氨酸天冬氨酸蛋白酶 3(caspase 3)活性,减少了与 ER 应激相关的细胞死亡。此外,通过降低α-平滑肌肌动蛋白(α-SMA)的 mRNA 和蛋白水平,bFGF 治疗抑制了肝星状细胞的激活。根据我们的发现,CerS-6/C16-神经酰胺的改变影响 ER 应激介导的炎症、氧化应激和细胞凋亡。bFGF 治疗通过下调 CerS-6/C16-神经酰胺和随后的 ER 应激相关通路,有效减轻了 NASH 的发展。