[Effects of HMGB1 on Proliferation and Secretion of Human Bone Marrow Mesenchymal Stem Cells]

To investigate the effect of high mobility group protein 1(HMGB1) on the proliferation and cytokine expression of human bone marrow mesenchymal stem cells (MSC).

Different concentrations of recombinant human HMGB1 protein (100, 200, 400, 800 and 1000 ng/ml) were incubated with MSC for 24, 48, 72 h and the proliferation of MSC were detected respectively by using the CCK-8 method and flow cytometry. The best concentrations of HMGB1 incubated with MSC was determined (200 ng/ml, 1000 ng/ml), and the flow cytomerty was used to determine the effect of HMGB1 on the proliferation of MSC. The mRNA expression levels of IL-10, TGF- β1, TSG-6 and IFN-γ in MSC incubated with HMGB1 protein were detected by real-time quantitative PCR and ELISA.

The result of MSC identification and flow cytometry showed that the CD105, CD73 and CD90 were expressed, but did not expression CD45, CD34, CD11b, CD19 and HLA-DR; CCK-8 showed that HMGB1 at the concentrations of 100 ng/ml, 200 ng/ml and 400 ng/ml could promote the proliferation of MSC incubated for 24, 48 and 72 h as compared with the control group (P<0.05), and the most effective concentration was 200 ng/ml; flow cytometry showed that the compared with the control group, HMGB1 200 ng/ml could induce MSC from G1 phase to S phase to promote the proliferation of MSC; QPCR showed that the mRNA expression of MSC cytokines IL-10, TGF-β1, TSG-6 increased while IFN-γ decreased at the concentration of 200 ng/ml HMGB1 as compared with the control group. ELISA experiments showed that the HMGB1 200 ng/ml acting on MSC for 48 h could significantly promoted the secretion of IL-10, TGF-β 1 and TSG-6(P<0．05), while IFN-γ showed no significant difference as compared with control group.

Recombinant human HMGB1 can promote the proliferation and secretion of MSC in healthy people.