Résumé
Non-alcoholic fatty liver disease (NAFLD), now referred to as "Metabolic dysfunction-associated fatty liver disease (MAFLD)," has become the most prevalent chronic liver disease worldwide. It is closely linked to obesity, type 2 diabetes, and insulin resistance. Its progression ranges from simple steatosis to more severe conditions such as non-alcoholic steatohepatitis ("Metabolic dysfunction-associated steatohepatitis (MASH)"), fibrosis, cirrhosis, and carries a significant risk of hepatocellular carcinoma (HCC). Although the recent FDA approval of resmetirom, a thyroid hormone receptor agonist, represents a promising therapeutic advancement for non-cirrhotic MASH, its efficacy across all stages of MAFLD remains to be fully elucidated. Furthermore, the precise pathophysiology of MAFLD is not yet completely understood, highlighting the need for reliable preclinical models to deepen the study of this disease and identify novel therapeutic targets.** **In vitro models are valuable tools for high-throughput studies, circumventing the limitations arising from interspecies differences observed in in vivo studies. Primary human hepatocytes (PHHs) are considered the gold standard for studying liver diseases and drug efficacy. However, maintaining their phenotype and functionality in culture, particularly in monoculture, presents significant challenges. Hepatic steatosis in PHHs is typically induced using free fatty acids, such as oleic or palmitic acid. However, these models generally lead to short-term steatosis, limiting their utility for long-term studies. To address these limitations, we developed a micro-organized co-culture (MOC) model of PHHs with murine fibroblasts, exposed to a hepatocyte-conditioned medium derived from stromal cells. This system enabled the long-term induction of hepatic steatosis over a period of at least 15 days, characterized by the accumulation of neutral lipids, disruptions in lipid and glucose metabolism, and insulin resistance. Moreover, RNA-seq analysis revealed several key pathways involved in the onset and progression of MAFLD. We further explored the therapeutic potential of bioactive lipids, particularly furan fatty acids (FuFAs), and demonstrated that they significantly mitigate these effects, making them promising candidates for future clinical studies targeting MAFLD and MASH.