Experimental Study On The Effect Of Cellular Skeleton And MAPK Signal Pathway On The Proliferation Of Osteoblast Under Low Load Mechanical Vibration

Background and purpose:With the increasing incidence of fracture in China,in addition to the traditional surgical treatment,we urgently need to explore a new non-invasive treatment.Recent studies have shown that low load mechanical vibration,as a non-drug therapy,has achieved good results in the treatment of osteoporosis and fracture by promoting the proliferation of osteoblasts.When cells are stimulated by mechanical signals.cytoskeleton plays an important role.in which the mitogen-activated protein kinase(MAPK)signaling pathway is closely related to the formation and function of cytoskeleton.The aim of this study was to investigate the effects of cytoskeleton and MAPK signaling pathway on osteoblast proliferation under low load mechanical vibration.Methods:The mouse embryonic osteoblast precursor cells(MC3T3-E1)were divided into two groups:control group and experimental group.The experimental group was given low load mechanical vibration for one week.The loading parameters were vibration frequency of 35 Hz and vibration intensity of 0.25 g.One week later,the proliferation of the cells in the control group and the experimental group was detected by cck-8 kit.Laser confocal microscopy was used to observe whether the cytoskeleton suffered structural damage under low load mechanical vibration.Then,microRNA microarray was used to detect the expression of differentially expressed genes in the control group and the experimental group,and real-time quantitative PCR was used to verify the results of the microarray.Results:After a week of low load mechanical vibration,the cell proliferation activity of the experimental group was enhanced.Laser confocal microscopy showed no significant chances in cytoskeleton under low load mechanical vibration compared with the control group.MiRNA gene chip results showed that there was a significant difference in gene expression between the experimental group and the control group.Mir-182-5p(degree=17),mir-150-5p(degree=13),mir-125b-2-3p(degree=11)and other differentially expressed genes affect the proliferation of osteoblasts by activating mapk signaling pathway and actin regulation pathway.Compared with the control group,the expression of miR-182-5p<0.01),miR-125b-2-3p(****p<0.0001)decreased and the expression of miR-150-5p increased(****p<0.0001)in the experimental group.The results were consistent with the results of gene chip.Conclusion:At 35 Hz,0.25g low load mechanical vibration could promote the proliferation of osteoblasts.Low load mechanical vibration can promote the proliferation of osteoblasts by up-regulating miR-150-5p,down-regulating miR-182-5p,miR-125b-2-3p expression and activating MAPK signaling pathway and actin regulation pathway.There was no obvious damage to cytoskeleton structure.