Negative pressure wound therapy promotes muscle-derived stem cell osteogenic differentiation through MAPK pathway

Negative pressure wound therapy (NPWT) has been revealed to be effective in the treatment of open fractures, although the underlying mechanism is not clear. This article aimed to investigate the effects of NPWT on muscle-derived stem cell (MDSC) osteoblastic differentiation and the related potential mechanism. The cell proliferation rate was substantially increased in NPWT-treated MDSCs in comparison with a static group for 3 days. There was no observable effect on the apoptosis of MDSC treated with NPWT compared with the control group for 3 days. The expression levels of HIF-1α, BMP-2, COL-I, OST and OPN were increased on days 3, 7 and 14, but the expression level of Runx2 was increased on days 3 and 7 in the NPWT group. Pre-treatment, the specific inhibitors were added into the MDSCs treated with NPWT and the control group. ALP activity and mineralization were reduced by inhibiting the ERK1/2, p38 and JNK pathways. The expression levels of Runx2, COL-I, OST and OPN genes and proteins were also decreased using the specific MAPK pathway inhibitors on days 3, 7 and 14. There were no significant effects on the expression of BMP-2 except on day 3. However, the expressions of the HIF-1α gene and protein slightly increased when the JNK pathway was inhibited. Therefore, NPWT promotes the proliferation and osteogenic differentiation of MDSCs through the MAPK pathway.