ABSTRACT
AIM:To investigate the roles of Notch signaling in lipopolysaccharide(LPS)-induced proliferation and secretion of interleukin-6(IL-6)and chemokine CXCL1 in bone marrow mesenchymal stem cells(BMSCs). METHODS:BMSCs were isolated by whole bone marrow culture.The expression levels of Notch signaling pathway recep-tors and ligands in the BMSCs treated with LPS were measured by qPCR and Western blot.The proliferation of BMSCs was analyzed by MTT assay and viable cell counting.The secretion levels of IL-6 and CXCL1 induced by LPS were measured by ELISA.RESULTS:Treatment with LPS at 1 mg/L effectively induced the proliferation of BMSCs and the secretion of IL-6.Obvious expression of Notch receptors and ligands in the BMSCs was observed,and LPS had little effect on the mRNA and protein levels of Notch receptors and ligands,but LPS increased the protein levels of Hes1 and Hey1,the target genes of Notch signaling.LPS at 1 mg/L increased the proliferation of BMSCs,whereas DAPT(Notch signal inhibitor)reduced the basal and LPS-induced proliferation of BMSCs(P<0.01).LPS treatment robustly increased the secretion of IL-6 and CXCL1 as assessed by ELISA.However,inhibition of Notch signaling almost completely abolished LPS-induced secretion of IL-6 and CXCL1(P <0.05).CONCLUSION: Inhibition of Notch signaling reduced not only the proliferation of BMSCs but also IL-6 and CXCL1 secretion induced by LPS.
ABSTRACT
<p><b>OBJECTIVE</b>To construct and identify lentiviral vector containing human ILK-shRNA and mda7 gene.</p><p><b>METHODS</b>Based on the human ILK gene sequences, RNAi target sequences were designed and cloned into the lentiviral vector pSicoR-eGFP by restriction endonuclease HpaI and XhoI double digestion and T4 DNA ligase ligation. Based on the human mda7 gene sequences, PCR primers were designed to clone the full-length mda7, and were cloned into the lentiviral vector pLVX-Puro. After the candidate clones were identified by DNA sequencing, the recombinant plasmid and the three packaging plasmids were co-transfected into the human embryonic kidney 293T cells by lipofectamine 2000 to produce the lentiviral particles. Human prostate cancer PC-3 cells were infected with the constructed lentiviral vector. The ILK and mda7 expression levels in PC-3 cells were quantified by qPCR and Western blot, respectively. The effect of ILK and mda7 on proliferation and migration of PC-3 cells were assessed by MTT method and Transwell assay, respectively.</p><p><b>RESULTS</b>ILK-pSicoR-eGFP and mda7-pLVX-Puro lentiviral vectors were successfully constructed. Strong green fluorescence was observed in the 293T cells under the fluorescent microscope after co-transfection of 293T cells with 4 plasmids of lentiviral vector. The transfection efficiency of the collected virus exceeded 90% in the 293T cells and the PC-3 cells were infected with the lentiviral particles with high efficiency. The A and B lentiviral vector inhibited the expression of ILK at both the mRNA and protein levels in PC-3 cells significantly. The mda7-pLVX-Puro lentiviral vector increased the expression of mda7 in PC-3 cells, and the ability was maintained for one month. Within 96 h, ILK and mad7 significantly inhibited the proliferation and migration of PC-3 cells (Ps<0.05).</p><p><b>CONCLUSION</b>The lentiviral vectors of ILK knockdown and mda7 over-expression have been successfully constructed and identified. The recombinant lentivirus can efficiently infect human prostate cancer PC-3 cells, in which ILK expression is inhibited and mda7 is over-expressed.</p>