Low-dose aspirin promotes osteogenic differentiation and osteogenic activity in osteoporotic rats by regulating Opg/Rankl/Rank Axis

Purpose: To investigate the effect of low-dose aspirin (ASP) on osteogenic differentiation and osteogenic effects in osteoporotic rats, and the associated mechanism.Methods: The bone marrow mesenchymal stem cells were randomly divided into 4 groups: control group and 3 drug groups treated with graded doses of ASP i.e. 0.5, 1 and 2 mmol/L, with 4 wells in each group. The OPG, RANKL protein expression levels, OPG/RANKL ratio, alkaline phosphatase (ALP) level, and ALP secretion at days 3, 5 and 7 were compared amongst the groups.Results: ALP secretion in BMSCs was markedly higher in the 1 mmol/L ASP group than in control (p < 0.05). The OPG protein concentration and OPG/RANKL ratio were markedly higher in ASP-treated BMSCs than in control, while RANKL protein expression level was significantly lower than that in control (p < 0.05). In BMSCs treated with ASP at doses of 0.5 and 2 mmol/L, OPG protein expression levels and ratio of OPG/RANKL were markedly lower than those in 1 mmol/L ASP group, while the mean level of RANKL protein expression was markedly higher than that in 1 mmol/L ASP group (p < 0.05).Conclusion: Low-dose aspirin increases the expression of ALP, and promotes calcification which relates to upregulation of OPG and inhibition of the OPG/RANKL/RANK axis. This provides new leads for the development of new anti-osteoporosis drugs. Keywords: Aspirin, OPG, RANKL, RANK, Osteoporosis