Tumor Necrosis Factor Alpha (TNF-α) Promotes The Immunosuppressive Effect Of Bone Marrow Stromal Cells (BMSCs) Of Mice Via NF-κB Pathway

Object:To explore the immunosuppressive effect of tumor necrosis factor alpha (TNF-α) acting on bone marrow stromal cells (BMSCs) of mice.Methods:BMSCs were cultivated via whole bone marrow adherent culture method and cell morphology was observed by inverted phase contrast microscope; the expression of surface marker of BMSCs, such as CD29、CD34and CD44were detected by flow cytometry,the expression of CXCR4was detected by immunofluorescence assay; the differentiation of BMSCs was identificated by oil red O and alcian blue stain; levels of the IL-10and prostaglandin E2(PGE2) of cell culture supernatant were detected by Elisa kits; western blot was used to measure cyclo-oxyge-nase-2(COX-2) and nuclear factor κB(NF-κB) protein levels of TNF-a treated and untreated BMSCs.Results:BMSCs in vitro were cultured adherently and presented in a clonal growth manner. Cells in the center of colony were mostly ball-shaped, while those on the edge of colony were spindle-shaped. The positive expression of CD29was84.89%and CD44was95.77%, while the expression of CD34was negative. The expression level of CXCR4was100%. BMSCs differentiated into adipocytes and chondroblasts varified by oil red O and alcian blue staining, respectively. The expression levels of IL-10and PGE2detected by Elisa kit were found significantly higher in the concentration of100ng/ml TNF-α treatment group than those in the control group (p=0.002<0.05), while when activated by TNF-a at the concentration of25ng/ml and50ng/ml,the expression of IL-10and PGE2showed no difference. The expression levels of COX-2and NF-κB detected by Western blotting were significantly higher in the TNF-a treatment group than those in the control group (p=0.02<0.05). Conclusion:The immunosuppressive effect of BMSCs can be enhanced by TNF-a in higher concentration which was mediated via NF-κB pathway.