Modeling of lung-liver interaction during infection in a human fluidic organ-on-a-chip

Respiratory infections, including pneumonia and COVID-19, are major causes of global mortality and morbidity. Recent advancements in organ-on-a-chip (OOC) technologies have paved the way for human-based disease models, offering new tools for studying disease mechanisms and accelerating drug development. The aim of this study was to establish a lung-liver fluidic system to study the interaction of both organ modules during infection. A two organ (lung / liver) fluidic system was established using primary human bronchial (HBECs) or alveolar type epithelial cells (AT) for the lung module and Huh-7 cells for the liver module. Inactivated non-typeable Haemophilus influenzae (NTHi) and Pseudomonas aeruginosa PAO1 (PAO1) were applied to the lung module. Secreted mediators were screened by dot-blot analysis and quantified. The impact of bacteria-exposed epithelial cells on the liver cell transcriptome was analyzed via mRNA sequencing. Lung and liver cells established stable cultures in a circulatory fluidic system. Activation of HBECs or ATCs with NTHi or PAO1 resulted in the secretion of multiple inflammatory mediators into the microfluidic medium including tumor necrosis factor-alpha (TNF-α), monocyte chemotactic protein-1 (MCP-1) and macrophage inflammatory protein-1-α (MIP-1α). Addition of lung cells and application of bacterial onto the HBEC module led to significant transcriptomic alterations in the liver cell module. Gene ontology enrichment analysis showed the induction of various pathways involved in host defense, metabolism, repair, and acute phase response. In conclusion, a two-organ lung/liver fluidic system was established to study the interaction of the organ modules during infection. Mediators like cytokines are released from epithelial culture modules into the fluidic circulation after exposure to bacterial pathogens that significantly modify the gene expression patterns of liver cells. A two organ (lung / liver) fluidic system was established using primary human bronchial (HBECs) or alveolar type epithelial cells (AT) for the lung module and Huh-7 cells for the liver module. Inactivated non-typeable Haemophilus influenzae (NTHi) and Pseudomonas aeruginosa PAO1 (PAO1) were applied to the lung module. Secreted mediators were screened by dot-blot analysis and quantified. The impact of bacteria-exposed epithelial cells on the liver cell transcriptome was analyzed via mRNA sequencing

呼吸道感染（包括肺炎与新型冠状病毒肺炎）是全球死亡与发病的主要诱因。
器官芯片（organ-on-a-chip, OOC）技术的最新进展为构建基于人体的疾病模型铺平了道路，为研究疾病机制、加速药物开发提供了全新工具。本研究旨在构建一套肺-肝流体芯片系统，以探究感染过程中两类器官模块的相互作用。

我们构建了双器官（肺/肝）流体芯片系统：肺模块采用原代人支气管上皮细胞（HBECs）或肺泡型上皮细胞（AT），肝模块则采用Huh-7细胞。将灭活的非分型流感嗜血杆菌（NTHi）与铜绿假单胞菌PAO1（PAO1）施加于肺模块。通过斑点印迹法（dot-blot analysis）对分泌的介质进行筛选与定量分析，并通过mRNA测序（mRNA sequencing）分析了细菌暴露后的上皮细胞对肝细胞转录组的影响。

肺细胞与肝细胞可在循环流体芯片系统中建立稳定培养体系。用NTHi或PAO1激活HBECs或AT细胞后，可向微流控培养基中分泌多种炎症介质，包括肿瘤坏死因子-α（TNF-α）、单核细胞趋化蛋白-1（MCP-1）以及巨噬细胞炎症蛋白-1α（MIP-1α）。将肺细胞引入系统并向HBEC模块施加细菌后，可使肝细胞模块出现显著的转录组变化。基因本体富集分析（Gene ontology enrichment analysis）显示，宿主防御、代谢、修复以及急性期反应相关的多条通路被激活。

综上，本研究成功构建了双器官肺/肝流体芯片系统，用于探究感染过程中器官模块间的相互作用。上皮培养模块在接触细菌病原体后，会向流体循环系统释放细胞因子等介质，这些介质可显著改变肝细胞的基因表达模式。

我们构建了双器官（肺/肝）流体芯片系统：肺模块采用原代人支气管上皮细胞（HBECs）或肺泡型上皮细胞（AT），肝模块则采用Huh-7细胞。将灭活的非分型流感嗜血杆菌（NTHi）与铜绿假单胞菌PAO1（PAO1）施加于肺模块。通过斑点印迹法（dot-blot analysis）对分泌的介质进行筛选与定量分析，并通过mRNA测序（mRNA sequencing）分析了细菌暴露后的上皮细胞对肝细胞转录组的影响。