Study On The Mechanism Of Icariin Promoting Osteoblast Autophagy Based On Mir-17-5p/MAPk/mTOR Signal

Objective: the long-term overuse of glucocorticoids will cause steroid induced necrosis of the femoral head,and the mechanism of steroid induced necrosis of the femoral head is more complex,so it is more difficult to treat steroid induced necrosis of the femoral head.At present,studies have found that autophagy is conducive to cell regeneration,and MAPK / mTOR signaling pathway has been confirmed to be involved in the regulation of autophagy.In recent years,it has been found that Epimedium has a significant effect in the treatment of steroid induced avascular necrosis of the femoral head.According to the research of network pharmacology,it is found that Epimedium may participate in the regulation and control of mir-17-5p/MAPK/mTOR signal axis,and promote the autophagy of steroid induced avascular necrosis of the femoral head.Therefore,this paper aims to explore the mechanism of icariin inducing mir-17-5p/MAPK/mTOR signaling pathway to promote osteoblast autophagy,so as to provide basic research support for the treatment of steroid induced osteonecrosis of the femoral head with icariin.Methods: rat osteoblast cell line ros1728 was divided into blank group,negative control group,icariin group,mir-17-5p inhibition group and icariin mTOR pathway inhibitor group.After 48 hours of treatment,the mRNA expression levels of mir-17-5p,mapk1 and mapk3 were detected by QRT PCR and Western blot The expression levels of ulk1,atg13,BCL2,lc3b and p62 were detected,and the changes of autophagy were observed by transmission electron microscope.Results: compared with the blank control group,the expression levels of mir-17-5p,ulk1,atg13,lc3b and p62 in icariin group were increased,while the expression levels of mapk1 and mapk3 mRNA were decreased(P < 0.01);compared with the negative control group,the expression levels of mir-17-5p,ulk1,atg13,lc3b and p62 in icariin group were increased,and the expression levels of mapk1 and mapk3 mRNA were increased Compared with icariin group,the expression levels of mir-17-5p,ulk1,atg13,p62 and lc3b in mir-17-5p inhibition group were decreased,while the expression levels of mapk1 and mapk3 in mir-17-5p inhibition group were decreased The expression levels of ulk1,atg13,p62 and lc3b in icariin mTOR pathway inhibitor group were higher than those in icariin group(P < 0.01).The results of electron microscopy showed that hormone could induce osteoblast damage and induce autophagy,while icariin could promote autophagy.Mir-17-5p inhibited autophagy and icariin mTOR inhibited autophagy The pathway inhibitor group promoted autophagy.Conclusion: icariin may enhance the expression of mir-17-5p in osteoblasts,inhibit the expression of MAPK mRNA,reduce the activity of mTOR,promote the formation of autophagosomes and promote the autophagy of osteoblasts.