| Objective To investigate whether estrogen can enhance the activity of Sirtl and then have an effect on osteoblasts and their pathways. Methods Different concentrations of 17β-E2 were applied to hFOB 1.19 after 24 hours, the autophagy of osteoblasts was detected by fluorescence autophagy detection kit (MDC); The expression of autophagy related protein LC3 was detected by Western blotting; The effect of AMPK, phosphorylated AMPK and SIRT1 on egg white activity was detected by Western blotting; SIRT1 was enhanced or inhibited in 17β-E2 environment. The changes of cell morphology and key proteins were observed by electron microscopy, confocal laser microscopy and flow cytometry; The effects of 17β-E2/SIRT1/AMPK/FOXO3a on autophagy related proteins Bcl-2, BNIP3, mTOR and caspase-3 were detected by immunoblotting and real-time quantitative PCR. Results 17β-E2 (10-8 mmol/L, 10-6 mmol/L) increased the autophagy of osteoblasts and the activity of lc3ii protein in osteoblasts; With the increase of 17β-E2 concentration, the expression of SIRT1 protein increased and the activity increased; 17β-E2 increased the level of phosphorylated AMPK, and AMPK increased the activity of SIRT1 in osteoblasts; SRT1720, SIRT1 agonist, and ex527, an inhibitor of SIRT1 It could interfere with the negative regulation of 17β-E2/SIRT1 on the apoptosis of osteoblasts; Using laser confocal microscopy and perspective electron microscopy to observe the LC3 protein regulated by 17β-E2/SIRT1 in osteoblasts, SRT1720 was found It could enhance the autophagy mediated by 17β-E2, increase the autophagy bodies in cells, and increase the mitochondrial autophagy bodies with double membrane structure; It could mediate SIRT1 protein, 17β-E2 could increase the expression of autophagy related proteins Bcl-2 and BNIP3, reduce the activity of mTOR and increase the activity of FOXO3a. Conclusion SIRT1 plays a key role in 17β-E2 mediated autophagy of osteoblasts; 17β-E2 may mediate autophagy of osteoblasts through AMPK/SIRT1/FOXO3a/mTOR pathway. |