Effect of yttrium ion on the proliferation,differentiation and mineralization function of primary mouse osteoblasts in vitro

A series of experimental methods including MTT test,alkaline phosphatase(ALP) activity measurement,oil red O stain and measurement and mineralized function were employed to assess the effects of Y3+ on the proliferation,differentiation,adipogenic transdifferentiation and mineralization function of primary mouse osteoblasts(OBs) in vitro.The results indicated that Y3+(1×10-9,1×10-8,1×10-7,1×10-6,1×10-5,and 1×10-4 mol/L) promoted the proliferation of OBs on day 1,2 and 3.Y3+ had no effect on the differentiation of OBs at concentrations of 1×10-9 and 1×10-8 mol/L,promoted the differentiation of OBs at concentration of 1×10-7 mol/L,but turned to inhibit the differentiation of OBs at other tested concentrations on day 1.On day 2,Y3+ inhibited the differentiation of OBs at all tested concentrations.On day 3,Y3+ promoted the differentiation of OBs at lower concentrations of 1×10-9 and 1×10-8 mol/L,but turned to inhibit the differentiation of OBs at other concentrations.Y3+ promoted the adipocytic transdifferentiation of OBs at most tested concentrations on day 9 and 12.On day 15,Y3+ promoted the adipocytic transdifferentiation of OBs at lower concentrations of 1×10-9 and 1×10-8 mol/L,turned to inhibit at other tested concentrations.Y3+ inhibited the formation of mineralized matrix nodules of OBs at concentrations of 1×10-9,1×10-8 and 1×10-6 mol/L,but turned to promote the formation of mineralized matrix nodules of OBs at other tested concentrations.These findings suggested that the effects of Y3+ on the proliferation,differentiation,adipocytic transdifferentiation and mineralization function of primary OBs depended on the concentration and culture time,moreover,concentration and culture time were pivotal factors for switching the biological effects of Y3+ from toxicity to activity,from damage to protection,or from down-regulation to up-regulation.