Agrimonia pilosa polysaccharide and its sulfate derives facilitate cell proliferation and osteogenic differentiation of MC3T3-E1 cells by targeting miR-107.

The present study showed that low level of miR-107 in femoral head tissues from rats suffering steroid-induced osteonecrosis of the femoral head (SANFH) was associated with high degree of osteonecrosis and apoptosis. In vitro assay, pretreatment with an Agrimonia pilos polysaccharide (APP-AW) and its sulphated derivatives (S2) at 50 μg/ml for 48 h or overexpressing miR-107 were able to prevent cytotoxicity induced by 1 μM dexamethasone (DEX) in MC3T3-E1 cells via inhibition of apoptosis. Meanwhile, the decreased ALP activity, collagen content, BMP2, Runx2, OSX and OCN protein expression in DEX-treated MC3T3-E1 cells were rescued by the addition of APP-AW and S2, or miR-107 transfection. Moreover, DEX-induced increase of Bax, cytochrome c and caspase-3, as well as decrease of Bcl-2, Wnt3, β-catenin and c-Myc protein expression in MC3T3-E1 cells were also reversed. These findings suggest that APP-AW and S2 promote cell proliferation and osteogenic differentiation by enhancing miR-107 during the development of SANFH.