Hydrocortisone Responsiveness of Rat Hepatocytes in Monolayer and Spheroid Cultures

Abstract

Hydrocortisone is a key regulator of energy metabolism, including the metabolic pathways of glucose and lipids. It is widely used to promote hepatic function in cultured hepatocytes. However, the relationship between hepatocyte morphology and hydrocortisone stimulation has not been thoroughly investigated. In this study, we evaluated the differential responsiveness of primary rat hepatocytes to hydrocortisone in monolayer and spheroid culture systems. Regardless of the presence or absence of hydrocortisone, the cells exhibited a flattened morphology in monolayer cultures, but formed organized three-dimensional structures with smooth surfaces in spheroid cultures. Hydrocortisone upregulated integrin expression in monolayers and cadherin expression in spheroids. In terms of hepatic metabolism, hydrocortisone upregulated the expression of genes involved in gluconeogenesis (phosphoenolpyruvate carboxykinase, Pepck), amino acid metabolism (tryptophan 2,3-dioxygenase, To), and the urea cycle (arginase 1, Arg1), particularly in spheroid culture. Albumin secretion and drug-metabolizing activity increased in a concentration-dependent manner in both culture systems, with drug metabolism notably enhanced in spheroids. These findings highlight that hydrocortisone is a critical factor in maintaining hepatocyte function, with the responsiveness of spheroids being superior to that of monolayers.