在慢性肝损伤过程中，炎症导致肝纤维化，特别是由于肝星状细胞（HSCs）的激活而引起。详细阐述了炎症细胞因子在HSC激活中的参与以及不同肝细胞之间的相互作用。为了在体外检验它们的相互作用，许多通过器官样或球体样培养的肝组织模型的随机三维结构正在进行中。在这里，我们证明了原代大鼠肝细胞与非实质细胞（如人源性HSC系列LX-2和肝窦内皮细胞系TMNK-1）的分级共培养。共培养组织具有高可用性，操作简单，可以分离固体和液体阶段，并改善肝脏功能，如白蛋白产生和肝细胞色素P450 3A4活性。我们还研究了供氧张力和关键的纤维化促进细胞因子转化生长因子β（TGF-β）对HSC激活的影响。在较低的氧气张力和TGF-β1刺激下，胶原纤维I和α-平滑肌肌动蛋白的基因表达在分级共培养中得到增强。因此，这种层级的体外共培养肝组织可作为疾病模型，为未来肝纤维化研究中各种肝细胞类型和生化信号的相互作用提供有用的平台。 版权所有 © 2023 The Society for Biotechnology, Japan. Elsevier B.V.发行。保留所有权利。

During chronic liver injury, inflammation leads to liver fibrosis, particularly due to the activation of hepatic stellate cells (HSCs). The involvement of inflammatory cytokines in HSC activation and the interplay among different liver cells are elaborated. To examine their interactions in vitro, many cultured liver tissue models are performed in organoid or spheroid culture with random 3D structure. Herein, we demonstrated the hierarchical coculture of primary rat hepatocytes with non-parenchymal cells such as the human-derived HSC line (LX-2) and liver sinusoidal endothelial cell line (TMNK-1). The cocultured tissue had high usability with simple operation of separating solid and liquid phases with improved liver functions such as albumin production and hepatic cytochrome P450 3A4 activity. We also studied the effects of stimulation by both oxygen tension and the key pro-fibrogenic cytokine, transforming growth factor beta (TGF-β), on HSC activation. Gene expression of collagen type I and alpha-smooth muscle actin were enhanced in the hierarchical coculture under lower oxygen tension and TGF-β1 stimulation. Therefore, this hierarchical in vitro cocultured liver tissue could provide a useful platform as a disease model for elucidating the interactions of various liver cell types and biochemical signals in future liver fibrogenesis studies.Copyright © 2023 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.