Background and Aims: TM6SF2 rs58542926 (E167K) is related to increased prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD). Conflicting mouse study results highlight the need for a human model to understand this mutation’s impact. This study aims to create and characterize a reliable human in vitro model to mimic the effects of the TM6SF2-E167K mutation for future studies. Approach and Results: We used gene editing on human human-induced pluripotent stem cells (iPSC) from a healthy individual to create cells with the TM6SF2-E167K mutation. After hepatocyte directed differentiation, we observed decreased TM6SF2 protein expression, increased intracellular lipid droplets and total cholesterol in addition to reduced VLDL secretion. Transcriptomics revealed upregulation of genes involved in lipid, fatty acid, and cholesterol transport, flux, and oxidation. Global lipidomics showed increased lipid classes associated with ER stress, mitochondrial dysfunction, apoptosis, and lipid metabolism. Additionally, the TM6SF2-E167K mutation conferred a pro-inflammatory phenotype with signs of mitochondria and ER stress. Importantly, by facilitating protein folding within the ER of hepatocytes carrying TM6SF2-E167K mutation, VLDL secretion and ER stress markers improved. Conclusions: Our findings indicate that induced hepatocytes generated from iPSCs carrying the TM6SF2-E167K recapitulate the effects observed in human hepatocytes from individuals with the TM6SF2 mutation. This study characterizes an in vitro model that can be used as a platform to identify potential clinical targets and highlights the therapeutic potential of targeting protein misfolding to alleviate ER stress and mitigate the detrimental effects of the TM6SF2-E167K mutation on hepatic lipid metabolism.

中文翻译：

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基于人诱导多能干细胞的脂质代谢相关 TM6SF2 E167K 变体的肝脏建模


背景和目的： TM6SF2 rs58542926 （E167K） 与代谢功能障碍相关脂肪性肝病 （MASLD） 患病率增加有关。相互矛盾的小鼠研究结果凸显了人类模型了解这种突变影响的必要性。本研究旨在创建和表征一个可靠的人类体外模型，以模拟 TM6SF2-E167K 突变的影响，以供未来研究。方法和结果： 我们对来自健康个体的人类诱导多能干细胞 （iPSC） 进行基因编辑，以产生具有 TM6SF2-E167K 突变的细胞。肝细胞定向分化后，我们观察到 TM6SF2 蛋白表达降低，细胞内脂滴和总胆固醇增加，此外 VLDL 分泌减少。转录组学揭示了参与脂质、脂肪酸和胆固醇转运、通量和氧化的基因的上调。全球脂质组学显示与 ER 应激、线粒体功能障碍、细胞凋亡和脂质代谢相关的脂质类别增加。此外，TM6SF2-E167K 突变赋予了具有线粒体和 ER 应激迹象的促炎表型。重要的是，通过促进携带 TM6SF2-E167K 突变的肝细胞内 ER 内的蛋白质折叠，VLDL 分泌和 ER 应激标志物得到改善。结论： 我们的研究结果表明，由携带 TM6SF2-E167K 的 iPSC 产生的诱导肝细胞概括了在具有 TM6SF2 突变个体的人肝细胞中观察到的效果。 本研究描述了一种体外模型，该模型可用作识别潜在临床靶点的平台，并强调了靶向蛋白质错误折叠的治疗潜力，以减轻 ER 应激并减轻 TM6SF2-E167K 突变对肝脏脂质代谢的不利影响。