Laboratory of Experimental Medicine and Pediatrics, Infla-Med Centre of Excellence, University of Antwerp, Antwerp, Belgium.
Department of Gastroenterology and Hepatology, Antwerp University Hospital, Antwerp, Belgium.
Cell Death Differ. 2024 Sep;31(9):1113-1126. doi: 10.1038/s41418-024-01348-9. Epub 2024 Jul 26.
There is an unmet clinical need for pharmacologic treatment for metabolic dysfunction-associated steatotic liver disease (MASLD). Hepatocyte cell death is a hallmark of this highly prevalent chronic liver disease, but the dominant type of cell death remains uncertain. Here we report that ferroptosis, an iron-catalyzed mode of regulated cell death, contributes to MASLD. Unsupervised clustering in a cohort of biopsy-proven MASLD patients revealed a subgroup with hepatic ferroptosis signature and lower glutathione peroxidase 4 (GPX4) levels. Likewise, a subgroup with reduced ferroptosis defenses was discerned in public transcriptomics datasets. Four weeks of choline-deficient L-amino acid-defined high-fat diet (CDAHFD) induced MASLD with ferroptosis in mice. Gpx4 overexpression did not affect steatohepatitis, instead CDAHFD protected from morbidity due to hepatocyte-specific Gpx4 knockout. The ferroptosis inhibitor UAMC-3203 attenuated steatosis and alanine aminotransferase in CDAHFD and a second model, i.e., the high-fat high-fructose diet (HFHFD). The effect of monounsaturated and saturated fatty acids supplementation on ferroptosis susceptibility was assessed in human HepG2 cells. Fat-laden HepG2 showed a drop in ferroptosis defenses, increased phosphatidylglycerol with two polyunsaturated fatty acid (PUFA) lipid tails, and sustained ferroptosis sensitivity. In conclusion, this study identified hepatic ferroptosis as a detrimental factor in MASLD patients. Unexpectedly, non-PUFA supplementation to hepatocytes altered lipid bilayer composition to maintain ferroptosis sensitivity. Based on findings in in vivo models, ferroptosis inhibition represents a promising therapeutic target in MASLD.
代谢相关脂肪性肝病(MASLD)存在未满足的临床药物治疗需求。肝细胞死亡是这种高发慢性肝病的一个标志,但主要的细胞死亡类型仍不确定。在这里,我们报告铁催化的细胞死亡调控模式——铁死亡,有助于 MASLD。对经活检证实的 MASLD 患者队列进行无监督聚类分析显示,存在具有肝铁死亡特征和较低谷胱甘肽过氧化物酶 4 (GPX4) 水平的亚组。同样,在公共转录组学数据集中也发现了具有降低铁死亡防御能力的亚组。4 周胆碱缺乏 L-氨基酸定义的高脂肪饮食(CDAHFD)可诱导小鼠发生 MASLD 并伴有铁死亡。过表达 Gpx4 不会影响脂肪性肝炎,相反,CDAHFD 可防止因肝细胞特异性 Gpx4 敲除引起的发病。铁死亡抑制剂 UAMC-3203 可减轻 CDAHFD 和第二种模型(即高脂肪高果糖饮食(HFHFD))中的脂肪变性和丙氨酸氨基转移酶。评估了单不饱和和饱和脂肪酸补充对铁死亡易感性的影响,在人 HepG2 细胞中进行。富含脂肪的 HepG2 细胞的铁死亡防御能力下降,具有两个多不饱和脂肪酸(PUFA)脂尾的磷脂酰甘油增加,并持续保持铁死亡敏感性。总之,本研究鉴定出肝铁死亡是 MASLD 患者的一种有害因素。出乎意料的是,非 PUFA 补充到肝细胞会改变脂双层组成以维持铁死亡敏感性。基于体内模型的研究结果,铁死亡抑制代表了 MASLD 的一个有希望的治疗靶点。