Background Liver metabolites are used to diagnose disease and examine drugs in clinical pharmacokinetics. Therefore, development of an in vitro assay system that reproduces liver metabolite recovery would provide important benefits to pharmaceutical research. However, liver models have proven challenging to develop because of the lack of an appropriate bile duct structure for the accumulation and transport of metabolites from the liver parenchyma. Currently available bile duct models, such as the bile duct cyst-embedded extracellular matrix (ECM), lack any morphological resemblance to the tubular morphology of the living bile duct. Moreover, these systems cannot overcome metabolite recovery issues because they are established in isolated culture systems. Here, we successfully established a non-continuous tubular bile duct structure model in an open-culture system, which closely resembled an in vivo structure. This system was utilized to effectively collect liver metabolites separately from liver parenchymal cells. Results Triple-cell co-culture of primary rat hepatoblasts, rat biliary epithelial cells, and mouse embryonic fibroblasts was grown to mimic the morphogenesis of the bile duct during liver development. Overlaying the cells with ECM containing a Matrigel and collagen type I gel mixture promoted the development of a tubular bile duct structure. In this culture system, the expression of specific markers and signaling molecules related to biliary epithelial cell differentiation was highly upregulated during the ductal formation process. This bile duct structure also enabled the separate accumulation of metabolite analogs from liver parenchymal cells. Conclusions A morphogenesis-based culture system effectively establishes an advanced bile duct structure and improves the plasticity of liver models feasible for autologous in vitro metabolite-bile collection, which may enhance the performance of high-throughput liver models in cell-based assays.

中文翻译：

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模拟胆管形态发生的管状胆管结构用于前瞻性体外肝脏代谢物回收。

背景 肝脏代谢物用于诊断疾病和检查药物的临床药代动力学。因此，开发一种重现肝脏代谢物回收率的体外测定系统将为药物研究提供重要的好处。然而，事实证明，肝脏模型的开发具有挑战性，因为缺乏合适的胆管结构来积累和运输来自肝实质的代谢物。目前可用的胆管模型，例如嵌入胆管囊肿的细胞外基质 (ECM)，与活胆管的管状形态缺乏任何形态相似性。此外，这些系统无法克服代谢物回收问题，因为它们是在孤立的培养系统中建立的。这里，我们成功地在开放培养系统中建立了一个非连续管状胆管结构模型，该模型与体内结构非常相似。该系统用于有效地从肝实质细胞中收集肝脏代谢物。结果 原代大鼠成肝细胞、大鼠胆管上皮细胞和小鼠胚胎成纤维细胞的三细胞共培养物生长以模拟肝脏发育过程中胆管的形态发生。用含有基质胶和 I 型胶原蛋白凝胶混合物的 ECM 覆盖细胞促进了管状胆管结构的发育。在该培养系统中，与胆管上皮细胞分化相关的特定标志物和信号分子的表达在导管形成过程中高度上调。这种胆管结构也使代谢物类似物从肝实质细胞中分离出来。结论 基于形态发生的培养系统有效地建立了先进的胆管结构，提高了肝脏模型的可塑性，可用于自体体外代谢物-胆汁采集，这可能会提高高通量肝脏模型在基于细胞的检测中的性能。