In Situ Regulation and Mechanisms of 3D Matrix Stiffness on the Activation and Reversion of Hepatic Stellate Cells

Abstract

Activated hepatic stellate cells (HSCs) is a key event in the progression of liver fibrosis. HSCs transdifferentiate into myofibroblasts and secrete large amounts of extracellular matrix, resulting in increased liver stiffness. It is difficult for platforms constructed in vitro to simulate the structure, composition, and stiffness of the 3D microenvironment of HSCs in vivo. Here, 3D scaffolds with different stiffness are constructed by decellularizing rat livers at different stages of fibrosis. The effects of matrix stiffness on the proliferation, activation, and reversion of HSCs are studied. The results demonstrate these scaffolds have good cytocompatibility. It is also found that the high stiffness can significantly promote the activation of HSCs, and this process is accompanied by the activation of integrin β1 as well as the nucleation and activation of Yes‐associated protein (YAP). Moreover, the low stiffness of the scaffold can promote the reversion of activated HSCs, which is associated with cell apoptosis and accompanied by the inactivation of integrin β1 and YAP. These results suggest that YAP may be a potential therapeutic target for the treatment of liver fibrosis and the theoretical feasibility of inducing activated HSCs reversion to the resting state by regulating matrix stiffness of liver.

Activated Hepatic Stellate Cells (Ito Cells) - Marker of Advanced Fibrosis in Chronic Viral Hepatitis C: A Pilot Study

“…Furthermore, the number of α-SMA HSCs was associated with LS. This observation is supported by previous studies which highlighted that LS is involved in HSCs activation, leading to their proliferation [95][96][97][98].…”

Combinatorial Microgels for 3D ECM Screening and Heterogeneous Microenvironmental Culture of Primary Human Hepatic Stellate Cells

“…This correlates well with the literature, as it has been shown in both 2D and 3D experiments that increasing the stiffness of the HSC substrate leads them to a more activated state. [ 8 , 32 , 51 , 52 ] In future studies, it would be of interest to identify if eight‐arm 8% µG bulk scaffolds have a distinct shear modulus compared to four‐arm 4% µG scaffolds and try to decouple the individual µG Young's modulus and the bulk scaffold's shear modulus effect on cell behavior. We also observed various combinatorial effects from the ECM and stiffness content of the scaffold.…”

“…[25][26][27][28] Here, we introduce the use of ECM protein-tagged PEG microgels of variable stiffnesses as 3D scaffolds for the culture of in vitro passaged (activated) primary human HSCs. The study of HSCs in 3D has been primarily limited to spheroid [29,30] or decellularized liver ECM [31,32] systems, where it is difficult to deconvolve the microenvironmental factors affecting cell behavior. PEG μG scaffolds allow us to isolate the effects of these factors by the selective modification of either the stiffness or the protein composition of the μGs.…”