Figure 1.

Cell sources and in vitro models used in NAFLD studies

Primary human hepatocytes (PHH), primary non-parenchymal cells (PNPC), stem cells and tumor-derived cell lines (cyan panel) can all be used to create two-dimensional (2D) and three-dimensional (3D) models for NAFLD (pink panel). 2D cultures (e.g., monocultures and co-culture) are denoted by a single or several cell types growing in a monolayer. 3D cultures (e.g., collagen gel sandwich, spheroids, organoids or liver-on-a-chip) have been recently introduced to elucidate NAFLD, and their development can rely on bio-printing technology. Self-aggregated spheroids present an accumulation of carbon dioxide (CO₂) and waste in their core. Cell culture models are listed by increasing cost, longevity and complexity. While complexity correlates with ability of the model to accurately capture the disease phenotype, simpler models are better suited to high-throughput applications.