Mechanism of Fuzheng Huayu Tablets against hepatic fibrosis based on transcriptome and single-cell sequencing

Abstract

This study aimed to investigate the role of macrophage polarization in the treatment of liver fibrosis by Fuzheng Huayu Tablets(FZHY) through single-cell, transcriptome sequencing and in vitro and in vivo experiments. Liver fibrosis-related datasets, transcriptomic datasets, and single-cell sequencing datasets were obtained from the Gene Expression Omnibus(GEO) database to screen differential genes. Liver fibrosis-related genes were obtained from GeneCards, DisGeNET, NCBI, PharmgKB, TTD and OMIM databases. Macrophage polarization-related genes were obtained from the GeneCards database. The above three gene sets were intersected to construct a protein-protein interaction(PPI) network. Cytoscape software was used to screen core proteins, and the expression pattern of core proteins was visualized by single-cell sequencing. A mouse model of liver fibrosis was constructed using carbon tetrachloride(CCl_4). Hematoxylin-eosin(HE) staining and Masson staining were used to observe the pathological morphology of liver tissues. The expressions of α-smooth muscle actin(α-SMA) and transforming growth factor-β1(TGF-β1) were detected by immunohistochemistry. The levels of alanine aminotransferase(ALT) and aspartate aminotransferase(AST) were detected by colorimetry. The le-vels of inflammatory factors in serum were detected by the enzyme-linked immunosorbent assay(ELISA). Furthermore, the expressions of α-SMA, TGF-β1, cluster of differentiation 86(CD86) and thrombospondin 1(THBS1) in liver tissues were detected by Western blot(WB). Lipopolysaccharide(LPS) was used to stimulate RAW264.7 cells to construct the M1 macrophage polarization model. The cell counting kit-8(CCK-8) method was used to detect cell viability. WB was used to detect the protein expressions of CD86 and THBS1 in cells, and the messenger ribonucleic acid(mRNA) expression levels of tumor necrosis factor-α(TNF-α) and interleukin(IL)-1β by real-time fluorescent quantitative reverse transcription polymerase chain reaction(RT-qPCR). The results showed that a total of 26 potential genes related to the polarization of liver fibrosis macrophages were obtained, and 10 core proteins related to the polarization of liver fibrosis macrophages such as THBS1, lumican(LUM) and fibulin-5(FBLN5) were screened. Single-cell data analysis indicated that THBS1, ranking highest, may be expressed by M1 macrophages. Animal experiments demonstrated that FZHY reduced inflammatory cell infiltration and collagen deposition in CCl_4-induced mouse liver, relieved liver injury and inflammation levels, and inhibited the expressions of α-SMA, TGF-β1, CD86, and THBS1 proteins. Cell experiments revealed that FZHY significantly reduced intracellular expression of CD86 and THBS1 proteins and mRNA levels of TNF-α and IL-1β. In conclusion, FZHY may ameliorate liver fibrosis by inhibiting THBS1 protein expression, suppressing M1 macrophage polarization, and reducing inflammation.