(610b) Multicellular Diseased Tissue Ensembles (MEDIATE) to Investigate the Role of Matrix Stiffness in Chronic Liver Disease

Chronic liver diseases (CLD) affect over 35 million americans with estimated health care costs of $10 billion per year. Irrespective of the etiology, liver fibrosis is a ubiquitous response with no FDA-approved interventions. Increase in liver stiffness (LS) (2 kPa to 25 kPa) is a key clinical readout of CLD progression but their plausible role in altering mitochondrial function and redox signaling in hepatocytes remains unclear. The purpose of this research is to elucidate the role of liver stiffness (LS) in disturbance of metabolic-redox signals that can increase the risk of hepatocytes dysfunction during CLD and provide basic insights into new therapies for CLD.

Methods:

Hepatic cell-line (VL-17A) cells were cultured on an innovative biomimetic platform “BEASTS (Bio-Engineered Adhesive Siloxane substrate with Tunable Stiffness)” that recreates physiologic (2 kPa) and pathologic stiffnesses (25 kPa and 55 kPa). We treated cells with and without ethanol (E) using 50mM concentration. In addition, we also utilize a known antioxidant drug, vitamin E, to the treated cells. We quantified reactive oxygen species (ROS) using H2DCFDA dye and lipid droplets using BODIPY staining for control and vitamin E treatments on all stiffness.

Data and Results:

The reactive oxygen species (ROS) was found to be stiffness dependent on both control and E treatment. Also, we found a higher ROS production in E treatment compared to control on 2 kPa and 55 kPa. This shows that stiffness contributes to the production of ROS causing mitochondrial dysfunction in the cells. We also quantified the lipid accumulation of VL-17A with and without E treatment to determine the effect of alcohol metabolism on all stiffness condition. We observed that the accumulation of lipid droplets increased in hepatocytes in fibrotic stiffness indicating the decreased ability of hepatocytes to process and metabolize lipids. Similar to the ROS production results, we found that the lipid droplets were higher in E treatment compared to control on all stiffnesses. This illustrates the effect of not only E treatment on cell metabolism but also the contributing factor of stiffness on cell function to metabolize alcohol.

Conclusions:

Stiffness plays a plausible role in chronic liver disease progression. Stiffness and vitamin E treatment affect oxidative stress production as well as lipid accumulation in VL-17A which are all crucial in cell metabolism and potentially provide a novel direction for therapeutic therapy for chronic liver diseases.