Fig. 5

Abrogation of MEL promotes BMSC osteogenic differentiation by circ_0003865 overexpression. a Relative expression of circ_0003865 and three osteogenesis marker genes in BMSCs. qRT-PCR was used to measure circRNA and mRNA levels in BMSCs. b The relative abundance of ALP, RUNX2, and OPN proteins in BMSCs. Osteogenesis marker protein abundances were determined by western blot analysis with GAPDH as the internal standard. c No significant change of proliferation in human BMSCs treated with MEL by circ_0003865 overexpression. CCK-8 assay was used to detect the proliferation. d Suppression of ALP expression in human BMSCs treated with MEL by circ_0003865 overexpression. ALP expression in BMSCs was detected by ALP staining. The top left are gross scanning images (scale bar: 1 mm), the lower left are enlarged images (magnification: × 250, scale bar: 160 μm), and the right is quantification of the left gross scanning images. e Inhibition of osteogenic differentiation of human BMSCs under MEL treatment by circ_0003865 overexpression. The Alizarin Red staining method was done to detect BMSC osteogenic differentiation. The top left are gross scanning images (scale bar: 1 mm), the lower left are enlarged images (magnification: × 250, scale bar: 160 μm), and the right is quantification of the left gross scanning images. MEL: melatonin; CCK-8: cell counting kit-8; ALP: alkaline phosphatase; RUNX2: runt-related transcription factor 2; OPN: osteopontin; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; *P < 0.05