The Effect Of Simvastatin On The Proliferation,Apoptosis And OPG MRNA RANKL MRNA In MC3T3-E1

ObjectiveTo evaluate the effect of Simvastatin on the proliferation, apoptosis and OPG,RANKLmRNA in MC3T3-E1, then investigate the possible mechanism of simvastatin on bone metabolism.Methods(1). Serial subcultivation of Murine preosteoblastic line MC3T3-E1.(2). MC3T3-E1 were cultured with different concentration of simvastatin. Cell proliferation was assessed by OD that analysed through MTT colorimetric assay(simvastatin 10-9,10-8,10-7, 10-6mol/L) and by cell cycle that analysed through flow cytometry(simvastatin 10-8,10-7,10-6, 10-5mol/L).(3). Given four concentration of simvastatin(10-8,10-7,10-6, 10-5mol/L) in MC3T3-E1, Apoptosis of MC3T3-E1 was assessed by percent of hypodiploid analysed by flow cytometry(4). The expressions of OPG,RANKLmRNA in MC3T3-E1 were obtained with semi-quantative RT-PCR, after cultured with several dose of simvastatin(10-9,10-8,10-7, 10-6mol/L).(5). Statistical analysis:Data are presented as x±s .All statistical analysis was performed with Windows SPSS11.5. The differences among the groups were determined by One-way ANOVE. Differences were considered significant at a value of P<0.05.Results(1). Proliferation of MC3T3-E1 was suppressed by simvastatin. Compared with the control group, proliferation of MC3T3-E1 was significantly suppressed in the trial groups by MTT and the difference is significance(P< 0.01), in dose-dependent manner. PI was significantly decreased in the trial groups by flow cytometry of DNA content analysis, compared with the control group(P<0.01). And there were significant differences among the trial groups , except the group between 10-8mol/L and 10-7mol/L and the group between 10-6mol/L and 10-5mol/L(P>0.05).(2). Apoptosis of MC3T3-E1 was promoted by simvastatin.Compared with the control group, percent of hypodiploid was increased in the trial group(sP<0.05).Differences among the groups were considered significant at a value of P<0.05,except the group between 10-6mol/L and 10-7mol/L(P>0.05). Meanwhile, observing the shape of cell under the microscope ,the activity of cell depressed, especially in 10-5 and 10-6mol/L. (3). Semi-quantative RT-PCR examination revealed that OPG mRNA expression was increased and RANKL mRNA expression was decreased in the trial groups after 24 hour subculture, compared with the control group. Simvastatin promoted OPG mRNA expression and inhibited the RANKL mRNA expression, in dose-dependent manner(P<0.01).Conclusions(1). Proliferation of MC3T3-E1 was suppressed by simvastatin.(2). Simvastatin promoted apoptosis of MC3T3-E1.(3). Simvastatin promoted OPG mRNA expression and inhibited RANKL mRNA expression. It proved that proliferation,differentiation and maturate of osteoclast was inhibited by simvastatin that promoted OPG mRNA expression and inhibited the RANKL mRNA expression.Then bone absorption was inhibited by simvastatin.