02008nas a2200313   4500000000100000000000100001008004100002260001500043653001800058653001700076653002800093653001800121100001800139700002000157700001300177700001500190700001700205700001700222700001700239700002300256700001700279700002100296245010800317856005500425300000900480490000600489520118500495022001401680       2023                            d  c2023-03-2310aAssay systems10acell culture10aGastrointestinal models10aLab-on-a-chip1 aJiandong Yang1 aYoshikazu Hirai1 aKei Iida1 aShinji Ito1 aMarika Trumm1 aShiho Terada1 aRisako Sakai1 aToshiyuki Tsuchiya1 aOsamu Tabata1 aKen-ichiro Kamei00aIntegrated-gut-liver-on-a-chip platform as an in vitro human model of non-alcoholic fatty liver disease  uhttps://www.nature.com/articles/s42003-023-04710-8  a1-140 v63 aNon-alcoholic fatty liver disease (NAFLD) afflicts a significant percentage of the population; however, no effective treatments have yet been established because of the unsuitability of in vitro assays and animal experimental models. Here, we present an integrated-gut-liver-on-a-chip (iGLC) platform as an in vitro human model of the gut-liver axis (GLA) by co-culturing human gut and liver cell lines interconnected via microfluidics in a closed circulation loop, for the initiation and progression of NAFLD by treatment with free fatty acids (FFAs) for 1 and 7 days, respectively. Co-cultured Caco-2 gut-mimicking cells and HepG2 hepatocyte-like cells demonstrate the protective effects from apoptosis against FFAs treatment, whereas mono-cultured cells exhibit induced apoptosis. Phenotype and gene expression analyses reveal that the FFAs-treated gut and liver cells accumulated intracellular lipid droplets and show an increase in gene expression associated with a cellular response to copper ions and endoplasmic reticulum stress. As an in vitro human GLA model, the iGLC platform may serve as an alternative to animal experiments for investigating the mechanisms of NAFLD.  a2399-3642