Polyphyllin Ⅰ enhances tumor necrosis factor-related apoptosis-inducing ligand-induced inhibition of human osteosarcoma cell growth via downregulating the Wnt/β-catenin pathway

OBJECTIVE:To investigate the synergistic effects of polyphyllin Ⅰ(PPⅠ)combined with tumor necrosis factorrelated apoptosis-inducing ligand(TRAIL)on the growth of osteosarcoma cells through downregulating the Wnt/β-catenin signaling pathway.METHODS:Cell viability,apoptosis and cell cycle distribution were examined using cell counting kit-8 and flow cytometry assays.The morphology of cancer cells was observed with inverted phase contrast microscope.The migration and invasion abilities were examined by xCELLigence real time cell analysis DP system and transwell assays.The expressions of poly(adenosine diphosphate-ribose)polymerase,C-Myc,Cyclin B1,cyclin-dependent kinases 1,N-cadherin,Vimentin,Active-β-catenin,β-catenin,p-glycogen synthase kinase 3β(GSK-3β)and GSK-3βwere determined by Western blotting assay.RESULTS:PPⅠ sensitized TRAIL-induced decrease of viability,migration and invasion,as well as increase of apoptosis and cell cycle arrest of MG-63 and U-2 OS osteosarcoma cells.The synergistic effect of PPⅠwith TRAIL in inhibiting the growth of osteosarcoma cells was at least partially realized through the inactivation of Wnt/β-catenin signaling pathway.CONCLUSION:The combination of PPⅠ and TRAIL is potentially a novel treatment strategy of osteosarcoma.

IRF family proteins and type I interferon induction in dendritic cells

Dendritic cells （DC）, although a minor population in hematopoietic cells, produce type I interferons （IFN） and other cytokines and are essential for innate immunity. They are also potent antigen presenters and regulate adaptive immunity. Among DC subtypes plasmacytoid DC （pDC） produce the highest amounts of type I IFN. In addition, pro- and anti-inflammatory cytokines such as IL-12 and IL-10 are induced in DC in response to Toll like receptor （TLR） signaling and upon viral infection. Proteins in the IRF family control many aspects of DC activity. IRF-8 and IRF-4 are essential for DC development. They differentially control the development of four DC subsets. IRF-8^-/- mice are largely devoid of pDC and CD8α^＋ DC, while IRF-4^-/- mice lack CD4^＋ DC. IRF-8^-/-, IRF4^-/-, double knock-out mice have only few CD8α CD4^-DC that lack MHC Ⅱ. IRF proteins also control type Ⅰ IFN induction in DC. IRF-7, activated upon TLR signaling is required for IFN induction not only in pDC, but also in conventional DC （cDC） and non-DC cell types. IRF-3, although contributes to IFN induction in fibroblasts, is dispensable in IFN induction in DC. Our recent evidence reveals that type Ⅰ IFN induction in DC is critically dependent on IRF-8, which acts in the feedback phase of IFN gene induction in DC. Type Ⅰ IFN induction in pDC is mediated by MyD88 dependent signaling pathway, and differs from pathways employed in other cells, which mostly rely on TLR3 and RIG-Ⅰ family proteins. Other pro-inflammatory cytokines are produced in an IRF-5 dependent manner. However, IRF-5 is not required for IFN induction, suggesting the presence of separate mechanisms for induction of type Ⅰ IFN and other pro-inflammatory cytokines. IFN and other cytokines produced by activated DC in turn advance DC maturation and change the phenotype and function of DC. These processes are also likely to be governed by IRF family proteins.

Integration of network and experimental pharmacology to decipher the antidiabetic action of Duranta repens L.

Objective:Duranta repens is reported to contain a wide array of secondary metabolites,including aamylase and a-glucosidase inhibitors,and-has potent antioxidant activity.The present study evaluated the network pharmacology of D.repens(whole plant)with targets related to diabetes mellitus and assessed its outcome by evaluating the effects of the hydroalcoholic extract of D.repens in streptozotocin-nicotinamide-induced diabetes mellitus in rats.Methods:Phytoconstituents of D.repens were retrieved from an open-source database and published literature,and their targets were predicted for diabetes mellitus using Binding DB and the therapeutic target database.Protein-protein interaction was predicted using STRING,and pathways involved in diabetes mellitus were identified using the Kyoto Encyclopedia of Genes and Genomes pathway browser.Druglikeness,ADMET profile(absorption,distribution,metabolism,excretion and toxicity)and cytotoxicity of compounds modulating proteins involved in diabetes were predicted using Mol Soft,admet SAR2.0 and CLC-Pred,respectively.The interaction network among phytoconstituents,proteins and pathways was constructed using Cytoscape,and the docking study was performed using Auto Dock4.0.The hydroalcoholic extract of D.repens was evaluated using streptozotocin-nicotinamide-induced diabetes mellitus animal model for 28 d,followed by an oral glucose tolerance test.At the end of the study,biochemical parameters like glycogen content,hepatic enzymes,antioxidant biomarkers and lipid profiles were quantified.Further,the liver and pancreas were collected for a histopathology study.Results:Thirty-six different secondary metabolites from D.repens were identified to regulate thirty-one targets involved in diabetes mellitus,in which protein-tyrosine phosphatase 1 B(PTP1 B)was primarily targeted.Enrichment analysis of modulated proteins identified 12 different pathways in diabetic pathogenesis in which the phosphatidylinositol 3-kinase-protein kinase B(PI3 K-Akt)signaling pathway was chiefly regulated.The docking study found that durantanin I possessed the highest binding affinity(à8.9 kcal/mol)with PTP1 B.Similarly,ADMET profiling showed that the majority of bioactive constituents from D.repens had higher human intestinal absorptivity and minimal cytotoxicity to normal cell lines,than tumor cell lines.Further,an in vivo animal study reflected the efficacy of the hydroalcoholic extract of D.repens to lower the elevated blood glucose level by stimulating insulin secretion,maintaining pancreatic b cell mass,regulating glycolysis/gluconeogenesis and enhancing the glucose uptake in skeletal muscles.Conclusion:The present study reflected the probable network interaction of bioactive constituents from D.repens,their targets and modulated pathways,which identified the prime regulation of the PI3 K-Akt signaling pathway and PTP1 B protein.Modulation of PTP1 B protein and PI3 K-Akt signaling pathway could contribute to enhancing glucose uptake,insulin production and glycolysis and decreasing gluconeogenesis in diabetes,which was evaluated via the experimental study.