ABSTRACT
In this study, we investigated the effect of Cigu Xiaozhi formula on HSC-T6 activity in hypoxic microenvironment based on network pharmacology and computer-aided drug design, and predicted and verified its possible targets and related signaling pathways. The potential active components and targets of Cigu Xiaozhi formula were screened by searching Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), Encyclopaedia of Traditional Chinese Medicine (ETCM) and Bioinformatics Analysis Tool for Molecular Mechanism of Traditional Chinese Medicine (BATMAN-TCM) databases, and the liver fibrosis related targets retrieved from Gene Cards and Pharm GK database were integrated to obtain the potential targets of Cigu Xiaozhi formula in the treatment of liver fibrosis. GO enrichment analysis and KEGG signaling pathway enrichment analysis were performed on Omic Share platform, and Cytoscape software was used to construct the "potential active ingredient-key target-pathway" network. The active components and target proteins were subjected to molecular docking analysis by Auto Dock software. According to the results of molecular dynamics simulation and binding free energy calculation, the top 5 active components with degree were scored. The active components stigmasterol and β-sitosterol were subjected to molecular docking. CoCl2 was used to induce HSC-T6 cells to construct hypoxia model in vitro. The cell viability was detected by CCK-8 assay, and the optimal time and concentration of hypoxia model of HSC-T6 cells was determined to be 100 µmol·L-1 CoCl2 for 24 h. Under hypoxia condition, HSC-T6 cells were activated, the wound healing rate was significantly increased, and the fluorescence signal of activation marker protein α-smooth muscle actin (α-SMA) was significantly enhanced. However, 6% drug-containing serum could inhibit the activation of HSC-T6 cells, and the wound healing rate was significantly decreased, and the fluorescence signal of α-SMA was significantly weakened. Further studies showed that the expressions of hypoxia-inducible factor-1α (HIF-1α), α-SMA and key proteins of Hedgehog (Hh) signaling pathway in HSC-T6 cells were up-regulated under hypoxia, while the expressions of HIF-1α, α-SMA, Patched-1 (Ptch-1) and glioma related oncogene homology-1 (Gli-1) were down-regulated in 6% drug-containing serum group, the YC-1 group and the cyclopamine group. These results indicated that HIF-1α and Hh signaling pathways were involved in the activation of HSC-T6 cells, and the traditional Chinese medicine Cigu Xiaozhi formula could inhibit the activation of HSC-T6 cells, and the mechanism may be related to the inhibition of HIF-1α expression and the blocking of Hh signaling pathway. In conclusion, Cigu Xiaozhi formula can inhibit the activation of HSC-T6 cells by directly acting on HIF-1α and Hh signaling pathway, and exert an anti-hepatic fibrosis effect. The animal experimental protocol has been reviewed and approved by Laboratory Animal Ethics Committee of Gansu University of Chinese Medicine, in compliance with the Institutional Animal Care Guidelines.
ABSTRACT
A previous study by our group indicated that combined treatment with taurine, epigallocatechin gallate (EGCG) and genistein protects against liver fibrosis. The aim of the present study was to elucidate the antifibrotic mechanism of this combination treatment using isobaric tag for relative and absolute quantification (iTRAQ)-based proteomics in an activated rat hepatic stellate cell (HSC) line. In the present study, HSC-T6 cells were incubated with taurine, EGCG and genistein, and cellular proteins were extracted and processed for iTRAQ labeling. Quantification and identification of proteins was performed using two-dimensional liquid chromatography coupled with tandem mass spectrometry. Proteomic analysis indicated that the expression of 166 proteins were significantly altered in response to combination treatment with taurine, EGCG and genistein. A total 76 of these proteins were upregulated and 90 were downregulated. Differentially expressed proteins were grouped according to their association with specific Kyoto Encyclopedia of Genes and Genomes pathways. The results indicated that the differentially expressed proteins hexokinase-2 and lysosome-associated membrane glycoprotein 1 were associated with glycolysis, gluconeogenesis and lysosome signaling pathways. The expression of these proteins was validated using western blot analysis; the expression of hexokinase-2 was significantly decreased and the expression of lysosome-associated membrane glycoprotein 1 was significantly increased in HSC-T6 cells treated with taurine, EGCG and genistein compared with the control, respectively (P<0.05). These results were in accordance with the changes in protein expression identified using the iTRAQ approach. Therefore, the antifibrotic effect of combined therapy with taurine, EGCG and genistein may be associated with the activation of several pathways in HSCs, including glycolysis, gluconeogenesis, and the ribosome and lysosome signaling pathways. The differentially expressed proteins identified in the current study may be useful for treatment of liver fibrosis in the future.
ABSTRACT
ETHNOPHARMACOLOGICAL RELEVANCE: Liver fibrosis is the result of long-term liver damage and the wound-healing process, in which the hepatic stellate cell (HSC) plays a crucial role during fibrogenesis. The liver sinusoidal endothelial cell (LSEC) is a liver-resident scavenger, contributing to sinusoidal remodeling, HSC activation and liver fibrosis. Lipopolysaccharide (LPS) causes an inflammatory reaction associated with portal circulation and LSECs signaling. Scutellariae radix, the root of Scutellaria baicalensis Georgi, is a Chinese herb widely used for liver diseases. However, its effect on LSEC activation and HSC migration in liver fibrosis has not been investigated yet. AIM OF THIS STUDY: LPS-induced rat LSEC (rLSEC) activation was used as a model to screen and explore the active components of Scutellariae radix. The anti-fibrotic effect of Scutellariae radix on rLSEC activation and rHSC migration was further investigated. MATERIALS AND METHODS: LPS-induced rLSEC mRNA expression, including VEGF, VEGFR, MCP-1, and TGF-ß1, were examined by real-time PCR analyses. MCP-1 protein levels were measured by an ELISA kit. rLSEC conditioned medium on rHSC migration was measured by wound-healing assay and transwell chemoattraction assay. RESULTS: Results showed LPS-induced rLSEC activation with upregulated MCP-1 mRNA and protein expressions, and that rLSEC-condition medium enhanced rHSC migration. Both baicalein and wogonin from the active subfraction significantly reduced MCP-1 expression, but only baicalein markedly inhibited rHSC migration in rLSEC conditioned medium. CONCLUSION: This study demonstrated that Scutellariae radix attenuates LPS-induced rLSEC activation and HSC migration with downregulation of MCP-1 expression. The results provide supporting evidence that Scutellariae radix may be beneficial for the amelioration of liver fibrosis.
