[Mechanism of Gynostemma pentaphyllum in treatment of metabolism associated fatty liver disease based on network pharmacology and molecular docking].

The present study explored the mechanism of action of Gynostemma pentaphyllum in the treatment of metabolism associa-ted fatty liver disease(MAFLD) by network pharmacology and molecular docking. The main active components and action targets of G. pentaphyllum were collected from TCMSP. Disease-related targets were obtained from GeneCards, OMIM and TTD, and the common targets of the three databases were screened out, which were converted to the genes with standard names by UniProt. The drug-disease common target genes were obtained through Venn tool and uploaded to STRING for the construction of the protein-protein interaction(PPI) network. Cytoscape was used to construct and analyze the drug-active component-common target-disease network. The gene ontology(GO) analysis and Kyoto encyclopedia of genes and genomes(KEGG) pathway enrichment analysis were performed on the common targets by DAVID. Pymol was adopted to perform molecular docking of active components and the common targets and predict their binding ability. Twenty-four active components(such as gypenosides, quercetin and sitosterol) of G. pentaphyllum were screened out. Ninety-two targets were obtained and 54 common targets were identified. Key targets included TNF, IL6, PTGS2, TP53, CCL2 and VEGFA. GO analysis on biological processes, molecular functions and cellular components and KEGG pathway analysis were performed, and the results indicated that NF-κB, PI3 K-Akt, TNF and HIF-1 signaling pathways were mainly involved. Molecular docking results showed that gypenosides and quercetin had a strong binding ability to TNF, IL6 and PTGS2. The findings of this study revealed that the therapeutic efficacy of G. pentaphyllum on MAFLD might be achieved by resisting inflammation and oxidative stress and improving insulin resistance, providing ideas and a theoretical basis for the development and application of G. pentaphyllum in the treatment of MAFLD.

Functional association of cytokine-induced SH2 protein and protein kinase C in activated T cells.

TCR signaling is mediated by intracellular signaling molecules and nuclear transcription factors, which are tightly regulated by interaction with regulatory proteins such as Grb2 and SLAP. We reported recently that TCR stimulation induces the expression of cytokine-induced SH2 protein (CIS). The expression of CIS promotes TCR-mediated activation. We have now found specific interactions between CIS and activated protein kinase C (PKC) alpha, beta and theta in TCR-stimulated T cells. CIS was shown by in vitro kinase assay to associate with activated PKC. In CIS-expressing T cells isolated from CIS-transgenic mice, the amount of activated PKC associated with CIS was found to increase following TCR stimulation. By immunohistochemical analysis, CIS was also found to co-localize with PKCtheta at the plasma membrane of activated T cells. In addition to the interaction and intracellular co-localization of the CIS and PKC, an increase in the activation of AP-1 and NF-kappaB was noted in CIS-expressing T cells, after stimulation by either anti-CD3/CD28 or phorbol myristate acetate + ionomycin. These results suggest that CIS regulates PKC activation, and that this may be important for the activation of both the AP-1 and NF-kappaB pathways in TCR signaling.