Extracellular Matrix Microstructures Directly Regulate Glutathione Bioavailability in Human Hepatocytes

Abstract

Recent works in mechanobiology have investigated overarching changes in cell behavior in response to extracellular matrix (ECM) stiffness. Nonetheless, little is known about how key metabolic pathways and critical metabolites are regulated by the ECM microstructures. Glutathione, a tripeptide predominantly synthesized in the liver, is a critical molecule used for the metabolism of certain xenobiotics and the reduction of oxidative species. Here, we report that the ECM microstructures can directly regulate the glutathione bioavailability and synthesis. By preparing a fibrous scaffold to mimic healthy native liver ECM and a flat substrate mimicking severe fibrotic conditions with the same surface chemistry, we found that the fibrous ECM upregulated glutathione levels in hepatocytes with enhanced antioxidation capacity. Mechanistic studies involving reducing and increasing integrin β1 activation suggested that ECM microstructures, integrin β1, and intracellular hepatic glutathione synthesis were mechanistically linked. These results represented an unprecedented discovery in mechanobiology regarding ECM microstructures’ role in regulating the hepatic metabolome, i.e., glutathione bioavailability, which can provide new insights into understanding and treating fibrotic liver diseases.