Precision Medicine Technologies
Tools to Resolve Disease Complexity
Hepatic stellate cell (HSC) is one of the major cell types responsible for the progression of liver fibrosis. Inhibition of HSC activation (i.e. transdifferentiation from an inactive / quiescent state to a myofibroblast like state) represents a compelling strategy for resolving liver fibrosis. Conventional 2D HSC culture cannot recapitulate the in-vivo 3D cell-ECM interactions and often causes undesirable cell activation due to the intrinsic mechanical properties of the plastic substrates. Hydrogel has emerged as a powerful tool for modeling the 3D cellular microenvironment in vitro, largely due to its chemical and physical versatility. To this end, GNF team has developed a comprehensive toolbox comprised of a variety of polyethylene, hyaluronic acid and gelatin based hydrogel derivatives. Specifically for modeling HSC activation, we’ve identified a gelatin methacrylate (GelMA)-based hydrogel formulation that preserves the quiescent state of HSCs much better than 2D culture on tissue culture polystyrene, and precisely controls the pro-fibrotic signal (i.e. TGFβ) induced activation in 3D. Such control offers optimal TGFβ induced response window superior to that of standard 2D culture, leading to robust assay performance in a highly miniaturized format. By leveraging GNF’s proprietary engineering / automation technologies, the 3D culture can be efficiently implemented in a 1536-well plate format with minimal inter-/intra-plate variations. Using a tool GNF compound set (with ~1800 compounds), our pilot high-content imaging (HCI) based phenotypic screen reveals an assay robust Z’ factor over 0.45 and a hit-picking rate ~3%. Overall, our automation-friendly, hydrogel-enabled 3D HSC assay can be readily scaled up either for primary screen or lead profiling applications, and the novel screening platform shown herein could offer broad utility to identifying novel targets or therapeutic modalities for diseases beyond liver fibrosis.