Single-cell transcriptomic analysis reveals heterogeneity of the patterns of responsive genes and cell communications in liver cell populations of zebrafish exposed to polystyrene nanoplastics

Abstract

Nanoplastics (NPs) are a group of emerging environmental pollutants with potential toxicity and health risk on biosystem and ecosystem. Great efforts have been devoted to describing the uptake, distribution, accumulation, and toxicity of NPs at various aquatic organisms; however, the heterogeneous response patterns in zebrafish (Danio rerio) liver cell populations caused by NP exposure have not yet been clarified. Investigation of the heterogeneous response patterns in zebrafish liver cell populations after NPs exposure provides us significances to explore the NP cytotoxicity. In this article, the heterogeneous response patterns in zebrafish liver cell populations after polystyrene (PS)-NPs exposure were studied. Significantly increased content of malondialdehyde and decreased levels of catalase and glutathione were observed, indicating the oxidative damage of zebrafish liver induced by PS-NPs exposure. Afterwards, the liver tissues were enzymatically dissociated and used for single-cell transcriptomic (scRNA-seq) analysis. Nine cell types were identified based on unsupervised cell cluster analysis followed by their marker genes. Hepatocytes were the cell type most impacted by PS-NP exposure, and heterogeneous response patterns of male and female hepatocytes were observed. The PPAR signaling pathway was up-regulated in hepatocytes from both male and female zebrafish. Lipid metabolism-related functions were altered more notably in male-derived hepatocytes, while female-derived…