Single-cell transcriptome reveals a novel mechanism of C-Kit+-liver sinusoidal endothelial cells in NASH

Abstract

Aim: To understand how liver sinusoidal endothelial cells (LSECs) respond to nonalcoholic steatohepatitis (NASH).

Methods: We profiled single-LSEC from livers of control and MCD-fed mice. The functions of C-Kit⁺-LSECs were determined using coculture and bone marrow transplantation (BMT) methods.

Results: Three special clusters of single-LSEC were differentiated. C-Kit⁺-LSECs of cluster 0, Msr1⁺-LSECs of cluster 1 and Bmp4⁺Selp⁺-VECs of cluster 2 were revealed, and these cells with diverse ectopic expressions of genes participated in regulation of endothelial, fibrosis and lipid metabolism in NASH. The number of C-Kit⁺-primary LSECs isolated from MCD mice was lower than control mice. Immunofluorescence co-staining of CD31 and C-KIT showed C-Kit⁺-LSECs located in hepatic sinusoid were also reduced in NASH patients and MCD mice, compared to AIH patients and control mice respectively. Interestingly, lipotoxic hepatocytes/HSCs cocultured with C-Kit⁺-LSECs or the livers of MCD mice receipting of C-Kit⁺-BMCs (bone marrow cells) showed less steatosis, inflammation and fibrosis, higher expression of prolipolytic FXR and PPAR-α, lower expression of TNF-α and α-SMA. Furthermore, coculturing or BMT of C-Kit⁺-endothelial derived cells could increase the levels of hepatic mitochondrial LC3B, decrease the degree of mitochondrial damage and ROS production through activating Pink1-mediated mitophagy pathway in NASH.

Conclusions: Hence, a novel transcriptomic view of LSECs was revealed to have heterogeneity and complexity in NASH. Importantly, a cluster of C-Kit⁺-LSECs was confirmed to recovery Pink1-related mitophagy and NASH progression.

Keywords: KIT proto-oncogene receptor tyrosine kinase (C-Kit); Liver sinusoidal endothelial cell (LSEC); Mitophagy; Non-alcoholic steatohepatitis (NASH); Single-cell RNA sequencing (scRNA-seq).