Klotho Inhibits Dex-induced Apoptosis Of MC3T3-E1 Osteoblasts Via NF-kb Signaling Pathway

Objective:To explore the mechanism by which klotho(KL)improves the inhibitory effect of dexamethasone(DEX)on MC3T3-E1 osteoblasts.Methods:Firstly,the transfection efficiency of recombinant adenovirus containing Klotho gene(Ad-KL)and recombinant adenovirus containing green fluorescent protein gene(Ad-GFP)in MC3T3-E1 cells was observed by using inverted fluorescence microscope,and KL protein levels was detected by Western blot.The viability of each group was detected by CCK-8.The relationship between NF-?B inhibitor pyrrolidine dithiocarbamate(PDTC)group and each group was analyzed by flow cytometry and Western blot.Western blot and qPCR were used to detect the expression of apoptotic proteins and the expression of NF-?B signaling pathway.The expression of I-?B protein and nuclear translocation of NF-?B p65 protein were analyzed by using a laser scanning confocal microscopy(LSCM).Results:MC3T3-E1 osteoblasts were transfected by Ad-KL successfully,and KL protein can be efficiently expressed in cells.DEX-induced apoptosis and Cleaved caspase-3 protein expression were significantly increased by CCK-8 and Western blot,while apoptosis was significantly decreased and cleaved caspase-3 protein expression was decreased after KL intervention.The NF-?B inhibitor PDTC reduced the number of DEX-induced apoptosis and attenuated DEX-induced caspase-3 activity.KL can inhiibit DEX-induced apoptosis of MC3T3-E1 cells and decrease the expression of caspase-3 by inhibiting DEX-induced I?B degradation,nuclear translocation of NF-?B p65 and phosphorylation of p65.Conclusion:KL can improve DEX-induced apoptosis of MC3T3-E1 cells by inhibiting the NF-?B pathway.In addition,KL may also improve DEX-induced apoptosis of MC3T3-E1 cells through other signaling pathways,and further studies are needed.The results of this study suggest that KL may be a new target for the future prevention and treatment of Glucocorticoid osteoporosis(GIOP).