自噬对糖皮质激素作用下MC3T3-E1成骨细胞增殖的影响

背景:目前,糖皮质激素(GCs)作用下成骨细胞自噬与其增殖能力的关系尚存争议.目的:探讨自噬对GCs作用下MC3T3-E1成骨细胞增殖能力的影响.方法:不同浓度(0、10-8 M、10-6 M、10-4 M)的地塞米松(DXMS)分别作用于MC3T3-E1成骨细胞,CCK-8检测不同时间(12 h、24 h、48 h)...

Effect of autophagy on the proliferation of MC3T3-E1 osteoblasts induced by glucocorticoid

Background:The relationship between autophagy and proliferation of osteoblasts under the action of glucocorti⁃coid is still controversial.Objective:To investigate the effect of autophagy on the proliferation of MC3T3-E1 osteoblasts under the action of glucocorticoid.Methods:Different concentrations of DXMS(0,10-8 M,10-6 M,10-4 M)were used to treat MC3T3-E1 osteoblasts,and CCK-8 was used to detect the proliferation of osteoblasts at different times(12 h,24 h,48 h).Western blot and cell immunofluorescence were used to detect the expression of Beclin-1 and LC-3 at 24 hours,and the number of autopha⁃gosomes was detected by transmission electron microscope to determine the characteristics of autophagy of osteoblasts treated with different concentrations of DXMS.Autophagy activator Rapamycin was added to osteoblasts cultured with 10-6 M DXMS to detect the changes of autophagy and cell proliferation by the same technique mentioned above,and to clarify the effect of au⁃tophagy on the proliferation of MC3T3-E1 osteoblasts under the action of glucocorticoid.Results:CCK-8 results showed that the higher the concentration of DXMS was,the stronger its inhibiting effect on MC3T3-E1 was.DXMS of 10-8 M had no effect on the proliferation of MC3T3-E1 osteoblasts(P>0.05);DXMS of 10-6 M showed significant effect(P<0.05);DXMS of 10-4 M showed most significant effect(P<0.05).Western blot,cell immunofluorescence and transmission electron microscope showed that with the increase of the concentration of DXMS,the expression levels of Beclin-1 and LC-3B increased consequently and the number of autophagosomes also significantly increased.The expression levels of Beclin-1 and LC-3B and the number of autophagosomes further increased after the adding of Rapamycin into osteoblasts cultured by DXMS of 10-6 M,and the prolifer⁃ation of osteoblasts also increased.Conclusions:Autophagy has a protective effect on the proliferation of osteoblasts under glu⁃cocorticoid.With the increase of glucocorticoid concentration,the level of autophagy increased but insufficient,which cannot resist the inhibitory effect of high glucocorticoid concentration on cell proliferation.Increasing the level of autophagy is helpful to promote the proliferation of osteoblasts.