Effects Of High-intensity Intermittent Exercise On The Wnt/β-catenin/Runx2 Pathway In Bone Tissue Of Female Growing Mic

Objective:To investigate the effects of four different exercise modes of high-intensity intermittent uphill exercise,high-intensity intermittent downhill exercise,moderate intensity sustained uphill exercise and moderate intensity downhill exercise on biochemical indexes of bone metabolism,bone mineral density,bone mineral content,and relative expression levels of Wnt/β-catenin/Runx2 signaling pathway in female growing mice.The effects of four exercise modes on bone were compared,and the influencing mechanism was discussed.Methods:Sixty 4-week-old female C57BL/6J mice were randomly divided into five groups after adaptive training for one week:high intensity intermittent uphill group（HU,n=12）,high intensity intermittent downhill group（HD,n=12）,medium intensity continuous uphill group（U,n=12）,medium intensity continuous downhill group（D,n=12）,and control group（C,n=12）.The exercise program is as follows:HU group performed 90%VO₂max exercise for 1 min and 40%VO₂max exercise for 4 min as a group,repeated for 8 groups,5 days a week,with a slope of+9°;HD group performed 90%VO₂max exercise for 1 min and 40%VO₂max exercise for 4 min as a group,repeated for 8 groups,5 days a week,with a slope of-9°;Group U carried out 60%VO₂max exercise,the exercise time was determined to ensure that the exercise distance of each group was the same,5 days a week,the slope was+9,and group D carried out 60%VO₂max exercise,the exercise time was determined to ensure that the exercise distance of each group was the same,5 days a week,the slope was-9.After 8 weeks of exercise,fasting for 24 hours,weighing before taking materials,anesthetized mice were injected intraperitoneally with 10%chloral hydrate solution at a dose of 3 ml per kilogram according to their body weight.After anesthesia,the bone mineral density and bone mineral content of the whole body of the mice were measured on the dual-energy X-ray absorptiometry（DEXA）.After the test,the mice were killed,blood was taken from the eyeball,and the femur was taken.The concentrations of bone alkaline phosphatase and tartar-resistant acid phosphatase were detected by enzyme-linked immunosorbent assay,and the content of Wnt3a proteinβ-Catenin protein and Runx2 protein expression.Compare the bone mineral density,bone mineral content,bone alkaline phosphatase,tartrate-resistant acid phosphatase and Wnt3a protein in each groupβ-The expression of Catenin protein and Runx2 protein.Results:1.After the experiment,the weight of mice in HD group,HU group,U group,D group and C group increased significantly（P<0.01-0.05）;Compared with group C,the weight of mice in HD group,HU group,U group and D group decreased significantly（P<0.01-0.05）,but there was no significant difference between HD group,HU group,U group and D group（P>0.05）.2.After the experiment,the bone mineral density of HD group,D group,HU group and U group increased significantly（P<0.01）;Compared with group C,the bone mineral density of mice in HD group,D group,HU group and U group was significantly higher（P<0.01）;Compared with U group mice,the bone mineral density of HD group mice was significantly higher（P<0.05）.3.After the experiment,compared with group C,the concentration of TRACP-5b in HD group mice decreased significantly（P<0.05）,while the concentration of TRACP-5b in D group,HU group and U group mice decreased,but there was no significant difference（P>0.05）;Compared with group C,the concentration of BALP increased,but there was no significant difference（P>0.05）.4.After the experiment,compared with group C,the Wnt3a protein and Runx2protein in HD group mice were significantly increased（P<0.01）,β-Catenin protein was significantly increased（P<0.05）,Wnt3a protein in HU group was significantly increased（P<0.05）,Runx2 protein was significantly increased（P<0.01）,Runx2protein in D group was significantly increased（P<0.01）,Wnt3a protein in U group was significantly increasedβ-Catenin protein and Runx2 protein increased,but there was no significant difference（P>0.05）;Compared with U group,Wnt3a protein in HD group was significantly higher（P<0.05）,Runx2 protein was significantly higher（P<0.01）,and Runx2 protein in HU group was significantly higher（P<0.01）;Compared with group D,the Runx2 protein of mice in HD group was significantly higher（P<0.01）,and the Runx2 protein of mice in HU group was significantly higher（P<0.05）.Conclusion:Both 8-week high-intensity intermittent exercise and medium-intensity continuous exercise can promote bone mass accumulation by enhancing bone formation and inhibiting bone resorption,and promote the expression of Wnt/β-catenin/Runx2 signaling pathway related proteins.The effect of high-intensity intermittent exercise is better than that of medium-intensity continuous exercise,and downhill high-intensity intermittent exercise is better than uphill high-intensity intermittent exercise.