Matrix stiffening induces hepatocyte functional impairment and DNA damage via the Piezo1‒ERK1/2 signaling pathway

Hepatocytes are the primary functional cells in the liver, and the malignant transformation of hepatocytes significantly contributes to hepatocellular carcinoma (HCC) progression. Liver fibrosis and cirrhosis caused by extracellular matrix (ECM) remodeling during liver lesions is a pivotal driver of HCC. However, the impact of matrix stiffness on hepatocytes and the underlying molecular mechanisms are not fully understood. Herein, using gelatin/sodium alginate hydrogels with different stiffnesses to simulate the change of matrix stiffness during liver lesions, we found that matrix stiffening leads to a notable decrease in the expression of hepatocyte nuclear factor 4α (HNF4α) and functional hepatocyte genes and a significant increase in the expression of interleukin 6 (IL‒6) in human hepatocyte line L‒02 cells, indicating obvious damage of hepatocyte function. In addition, matrix stiffening causes extensive DNA damage to L‒02 cells. Mechanistically, matrix stiffening upregulates piezo‒type mechanosensitive ion channel component 1 (Piezo1) expression and activates extracellular signal‒regulated kinase 1/2 (ERK1/2) signaling. Piezo1 knockdown suppresses matrix stiffening‒induced functional impairment and DNA damage in L‒02 cells. Moreover, Piezo1 knockdown blocks matrix stiffening‒activated ERK1/2 signaling in L‒02 cells. U0126 (a selective inhibitor of ERK1/2 activation) treatment could rescue matrix stiffening‒induced functional impairment and DNA damage. Taken together, these findings demonstrate that matrix stiffening induces functional impairment and DNA damage in L‒02 cells via the Piezo1‒ERK1/2 signaling pathway, which provides evidence for a better understanding of the hepatocyte function damage caused by tissue mechanical microenvironment change in liver diseases and the mechanotransduction in this process.