Search

A series of experimental methods including 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide (MTT) test, alkaline phosphatase (ALP) activity measurement, Oil Red O stain and measurement, mineralized function expression and quantitive real time RT-PCR (qRT-PCR) were employed to assess the effect of Nd3+ and Sm3+ on the proliferation, differentiation and mineralization function of primary osteoblasts (OBs) in vitro at cell and molecular levels. The experimental results suggest that concentration, culture time and ion species are pivotal factors for switching the biological effects of rare earth ions from toxicity to activity, from damage to protection, or from down-regulation to up-regulation. [ABSTRACT FROM AUTHOR]

A series of experimental methods including 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) test, alkaline phosphatase (ALP) activity measurement, mineralized function, Oil Red 0 stain and measurement were employed to assess the effect of Dy3+ on the osteogenic and adipogenic differentiation of mouse primary bone marrow stromal cells (BMSCs) and the adipogenic trans-differentiation of mouse primary osteoblasts (OBs). The results showed that Dy3+ had no effect on BMSC proliferation at concentrations of 1 x 10-8 and 1 x 10-5 mol/L, but inhibited BMSC proliferation at other concentrations. Dy3+ had no effect on OB proliferation at concentrations of 1 x 10-10 and 1 x 10-9 mol/L, but inhibited OB proliferation at other concentrations. Dy3+ had no effect on the osteogenic differentiation of BMSCs at concentrations of 1 x 10-9 and 1 x 10-7 mol/L, and promoted osteogenic differentiation of BMSCs at other concentrations at the 7th day. The osteogenic differentiation of BMSCs was inhibited by Dy3+ at concentration of 1 x 10-5 mol/L at the 14th day, but promoted osteogenic differentiation of BMSCs at concentrations of 1 x 10-9, 1 x 10-8, 1 x 10 -7 and 1 x 10-6 mol/L with the maximal effect at concentration of 10-6 mol/L. Dy3+ promoted mineralized function of BMSCs at any concentration. Dy3+ had no effect on adipogenic differentiation of BMSCs at concentration of 1 x 10-7 mol/L, but inhibited adipogenic differentiation of BMSCs at other concentrations. Dy3+ inhibited adipocytic trans-differentiation of OBs at any concentration, suggesting that Dy3+ had protective effect on bone and the protective effect on bone may be mediated by modulating differentiation of BMSCs away from the adipocyte and inhibiting adipocytic trans-differentiation of OBs which may promote differentiation and mineralization of OBs. These results may be valuable for better understanding the mechanism of the effect of Dy3+ on pathogenesis of osteoporosis. [ABSTRACT FROM AUTHOR]