An in vitro 3D spheroid model with liver steatosis and fibrosis on microwell arrays for drug efficacy evaluation.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is now the most common chronic liver disease worldwide, affecting more than 30 percent of adults. The most severe form of MASLD, metabolic dysfunction-associated steatohepatitis (MASH), is characterized by necrotizing inflammation and rapid fibrosis progression, often leading to cirrhosis and hepatocellular carcinoma. Currently, only Resmetirom is approved for the treatment of MASH one of the main reasons is the absence of representative in vivo or in vitro models for MASH. To address this challenge, we developed a high-throughput 3D spheroid model consisting of human hepatocellular carcinoma cells (HepG2) and human hepatic stellate cells (LX-2) on microwell arrays. This model, induced with free fatty acids (FFA) to simulate steatosis and fibrosis, enables the assessment of efficacy and mechanisms for potential anti-MASH drugs. Our findings demonstrate that this in vitro spheroid model replicates key pathological features of human MASLD, including steatosis, oxidative stress, and fibrosis. Upon validation, we selected pirfenidone (PFD) and yinfenidone (AC-003), which are commonly used to treat idiopathic pulmonary fibrosis (IPF), to test their anti-MASH efficacy. Treatment with these drugs showed that they could regulate lipid synthesis and metabolism genes, reduce lipid accumulation, oxidative stress, and fibrosis levels. This 3D spheroid model represents a straightforward and efficient tool for screening anti-MASH drugs and investigating the molecular mechanisms of drug action.