Single-cell metabolic profiling reveals subgroups of primary human hepatocytes showing heterogeneous responses to drug challenge

Abstract

Xenobiotics are primarily metabolized by hepatocytes in the liver, and primary human hepatocytes (PHHs) are the gold standard model for the assessment of drug efficacy, safety and toxicity in the early phases of drug development. Recent advances in single-cell genomics have shown liver zonation and ploidy as main drivers of cellular heterogeneity. However, little is known about the impact of hepatocyte specialization on liver function upon metabolic challenge, including hepatic metabolism, detoxification, and protein synthesis. Here, we investigate the metabolic capacity of individual human hepatocytes in vitro, and assess how chronic accumulation of lipids enhances cellular heterogeneity and impairs the metabolisms of drugs. A phenotyping five-probe cocktail was used to identify four functional subgroups of hepatocytes that respond differently to drug challenge and fatty acid accumulation. These four subgroups display differential gene expression profiles upon cocktail treatment and xenobiotic metabolism-related specialization. Notably, intracellular fat accumulation leads to increased transcriptional variability and diminished the drug-related metabolic capacity of hepatocytes. Our results demonstrate that, upon a metabolic challenge such as exposure to drugs or intracellular fat accumulation, hepatocyte subgroups lead to different and heterogeneous transcriptional responses.

Human induced pluripotent stem cell–derived liver-on-a-chip for studying drug metabolism: the challenge of the cytochrome P450 family

“…Liver zonation, hepatocyte polarization, or the spatial distribution of cells in the liver lobules are also key for the recapitulation of specific features. The hepatocytes distributed along the pericentral and periportal vein differ in the expression of several markers and, notably, drug metabolism genes are mainly expressed in the pericentral zone ( Brosch et al, 2018 ; Sanchez-Quant et al, 2022 ). OoC systems with a focus on drug metabolism that fully recapitulate zonation are currently lacking, although attempts to address this are ongoing ( Tonon et al, 2019 ; Danoy et al, 2020 ).…”