Liver cirrhosis is a prevalent condition worldwide, closely associated with the progression of chronic liver diseases and a critical precursor to liver cell carcinoma. Due to its insidious onset and the lack of effective treatment options, liver cirrhosis remains a major global health challenge, emphasizing the importance of intervention at the early stages of the disease. At the 58th Annual Meeting of the European Association for the Study of the Liver (EASL 2023) and the EASL Congress 2023, Dr. Junqi Niu’s team from the First Hospital of Jilin University introduced their latest findings on the mechanisms underlying liver fibrosis. They provided bulk and single-cell RNA sequencing data on human hepatic stellate cells (HSCs) and potential biomarkers for liver cirrhosis.
The exact mechanisms driving liver fibrosis are not yet fully understood, and there is a significant unmet medical need for anti-fibrotic treatments. Research into highly efficient and specific anti-fibrotic drugs has become a hot and challenging topic in the field of liver diseases. Hepatic stellate cells (HSCs) play a central role in liver cirrhosis, and understanding the signals and intracellular events that drive HSC activation contributes to unraveling the molecular mechanisms of liver fibrosis.
Because predicting human diseases based on animal experiments becomes complicated due to species differences, most cell lines are tumor-like cells with long-term passaging capabilities, which cannot reflect the real disease conditions. Therefore, the team of Professor Junqi Niu used primary HSCs obtained from patients for targeted bulk and single-cell transcriptomic analysis. In the bulk RNA sequencing, two comparative schemes were used: Scheme A compared HSCs from 9 cirrhosis patients to HSCs from 6 non-cirrhosis patients, and Scheme B compared 7 cultured activated HSCs to 7 freshly isolated HSCs (paired analysis).
In bulk RNA sequencing, Scheme A and B identified 3828 and 2262 differentially expressed genes, respectively. These differentially expressed genes were significantly enriched in pathways related to “adherens junctions,” “retinol metabolism,” and “collagen or ECM formation, assembly, or degradation.” Subsequent protein-protein interaction analysis identified CAV1, ESR1, APP, SHC1, BCR, and LPL as key genes, which could be potential therapeutic targets of interest. Upstream transcription factors predicted by the KnockTF database, based on the transcription factor-differentially expressed gene network, highlighted POU5F1, ZFX, RARA, and MXD3 as important upstream transcription factors involved in regulating the differentially expressed genes in this study.
Single-cell sequencing included 4 cases of hepatitis B virus-related liver cirrhosis and 3 cases of normal liver tissue. A cell population characterized by high expression of DCN, ACTA2, COL1A1, and TAGLN was identified as myofibroblast-like HSCs. Temporal analysis indicated that this population was located at the terminal end of the differentiation trajectory, regulated by cirrhosis-related endothelial cells through key ligand-receptor pairs such as PDGFs-PDGFRs, ANGPTL4-SDC2/SDC4/ITGA5+ITGB1, and NAMPT-ITGA5+ITGB1. Integrated data revealed that the 38 upregulated genes in myofibroblast-like HSCs from single-cell sequencing were shared with bulk RNA sequencing.
In summary, Professor Junqi Niu’s team has provided multiple sequencing datasets, revealing the characteristics of human HSC changes and exploring possible mechanisms of liver fibrosis development as well as potential diagnostic and therapeutic targets. This research forms a theoretical basis for the clinical application of anti-fibrotic drugs. In the future, cell-type-specific and target-specific drug interventions will make anti-fibrotic treatments more effective.
First Author:
Dr. Xu Liu
Department of Gastroenterology, The First Hospital of Jilin University, Physician
TAG: EASL2023;Vioce of China;Liver Fibrosis
