LEADS - a comprehensive human liver-on-a-chip for non-alcoholic steatohepatitis (NASH) drug testing

Metabolic dysfunction associated steatohepatitis (MASH), also known as non-alcoholic steatohepatitis (NASH), is a progressive form of steatotic liver disease (SLD). It is an emerging healthcare threat due its high prevalence, accelerated and non-linear progression, and final culmination as decompensated liver failure and/or hepatocellular carcinoma (HCC). The pathogenesis of NASH is complex with strong ethnic influences and genetic predispositions, underscoring the need for preclinical models that utilize patient-derived cells to enhance our understanding of the disease. Current models face three major limitations: (i) reliance on primary cells with limited reproducibility, high cost, short culture duration and ethical considerations, (ii) failure to recapitulate all key features of NASH, and (iii) inadequate drug testing data and/or data did not correlate with clinical responses. Therefore, there is a pressing need for robust and relevant preclinical models that faithfully recapitulate human NASH, allow generation of patient-specific models and provide quantitative responses for mechanistic studies and drug testing. We have developed a functional liver tissue-on-a-chip by co-culturing human adult liver stem cell (haLSC)-derived hepatobiliary organoids, induced pluripotent stem cell (iPSC)-derived Kupffer cells (iKCs) and iPSC-derived hepatic stellate cells (iHSCs). We simulated the metabolic microenvironment of hyper nutrition and leaky gut by treating the cells with a concoction of free fatty acids (FFAs), fructose, gut-derived lipopolysaccharides (LPS) and a gut-derived metabolite, phenyl acetic acid (PAA). Through optimization of co-culture media and induction regimens, we were able to stably induce steatosis, hepatocellular ballooning, inflammation, and activation of iHSC and fibrosis-all key hallmarks of NASH. Our LEADS (liver-on-a-chip for NASH drug testing) model also recapitulated the pathological types of steatosis and allowed for quantification of the key features via microscopic evaluation and secretome profiling to score for disease severity. Notably, treatment with saroglitazar, pioglitazone, cenicriviroc (CVC), obeticholic acid (OCA) and resmetirom produced responses similar to those observed in clinical trials. Taken together, our LEADS model is the first model developed using patient-derived hepatic stem cells which recapitulated all key features used for comprehensive drug testing, with results matching to clinical responses.