Spatial hepatocyte plasticity of gluconeogenesis during the metabolic transitions between fed, fasted and starvation states

Abstract

Hepatocytes are organized along a spatial axis between the portal triad and the central vein to form functionally repetitive units known as lobules. The hepatocytes perform distinct metabolic functions depending on their location within the lobule. Single-cell analysis of hepatocytes across the liver lobule demonstrates that gluconeogenic gene expression is relatively low in the fed state and gradually increases in the periportal hepatocytes during the initial fasting period. As fasting progresses, pericentral hepatocyte gluconeogenic gene expression and gluconeogenic activity also increase and, following entry into a starvation state, the pericentral hepatocytes show similar gluconeogenic gene expression and activity to the periportal hepatocytes. In parallel, starvation suppresses canonical β-catenin signalling and modulates the expression of pericentral and periportal glutamine synthetase and glutaminase, respectively, resulting in enhanced incorporation of glutamine into glucose. Thus, hepatocyte gluconeogenic gene expression and glucose production are spatially and temporally plastic across the liver lobule, underscoring the complexity of defining hepatic insulin resistance and glucose production on a whole-organ level, as well as for a particular fasted or fed condition.