摘要
目的:探究不同力学刺激介导 2 型糖尿病(T2DM)小鼠骨中JAK2/STAT3 途径进而调控OC分化及骨吸收的作用机制.方法:将 40 只 4 周龄雄性C57BL/6 小鼠随机分为正常对照组(ZC,10 只)和T2DM建模组(TJ,30 只).利用 6 周高脂膳食结合一次性注射链脲佐菌素法进行T2DM小鼠造模.成功后,随机分为T2DM对照组(TC,9 只)、T2DM游泳组(TS,9 只)和T2DM下坡跑组(TD,9 只),并进行 8 周运动干预.结束后,利用RT-PCR检测骨和OC中相关因子mRNA表达;利用West-blotting检测骨中相关因子蛋白表达;对分化产生OC TRAP染色后计数;石蜡包埋切片后TRAP染色,观察TRAP活性变化;利用Micro-CT检测BMD变化.结果:(1)与ZC组相比,TC组骨中JAK2 mRNA表达下调(P＜0.05),STAT3、NFATc1、CTSK、c-fos mRNA和NFATc1、CTSK、c-fos蛋白表达上调(P＜0.05 或P＜0.01),OC中TRAP、NFATc1、PU.1、c-fos和c-Src mRNA表达上调(P＜0.01);OC和多核OC数量增多(P＜0.01)、骨TRAP活性增强和BMD下降(P＜0.01);(2)与TC组相比,TS组骨中CTSK mRNA表达和NFATc1 蛋白表达下调(P＜0.05),OC中c-fos mRNA表达下调(P＜0.05);TD组骨中JAK2mRNA表达上调(P＜0.01),STAT3、NFATc1、CTSK、c-fos mRNA和NFATc1、CTSK、c-fos蛋白表达均下调(P＜0.05 或P＜0.01),OC中TRAP、NFATc1、PU.1、c-fos和c-Src mRNA表达下调(P＜0.05 或P＜0.01),OC和多核OC数量减少(P＜0.05 或P＜0.01),骨TRAP活性下降,而BMD升高(P＜0.01).(3)与TS组相比,TD组骨中JAK2 mRNA表达上调(P＜0.05),STAT3、NFATc1、CTSK、c-fos mRNA和NFATc1、CTSK、c-fos蛋白表达均下调(P＜0.05);OC中TRAP、NFATc1、PU.1、c-fos和c-Src mRNA表达下调(P＜0.05);OC和多核OC数量减少(P＜0.05),骨TRAP活性明显下降,而BMD升高(P＜0.01).结论:下坡跑对骨产生的地面反作用力通过JAK2/STAT3 途径抑制T2DM小鼠OC分化及骨吸收,增加骨量,而游泳对骨产生的肌肉牵拉力作用不明显.
Abstract
Objective:To explore the mechanism of JAK2/STAT3 pathway in the bones of type 2 diabetes mellitus(T2DM)mice mediated by different mechanical stimuli to regulate OC differentiation and bone resorption.Methods:Forty 4-week-old male C57BL/6 mice were randomly divided into normal control group(ZC,n=10)and T2DM modeling group(TJ,n=30).A 6-week high-fat diet combined with a one-time injection of streptozotocin was used to model T2DM mice.After success,they were randomly divided into a T2DM control group(TC,n=9),a T2DM swimming group(TS,n=9)and a T2DM downhill running group(TD,n=9),and 8 weeks of exercise intervention were performed.After the end,RT-PCR was used to detect the expression of related factors in bone and OC;West-blotting was used to detect the expression of related factor proteins in bone;OC TRAP staining for differentiation and counting;TRAP staining after paraffin-embedded sections to observe the changes in TRAP activity;Micro-CT was used to detect BMD changes.Results:(1)Compared with the ZC group,the expression of JAK2 mRNA in the bone of the TC group was down-regulated(P＜0.05),and the expression of STAT3,NFATc1,CTSK,c-fos mRNA and NFATc1,CTSK,and c-fos protein were up-regulated(P＜0.05 or P＜0.01),the expression of TRAP,NFATc1,PU.1,c-fos and c-Src mRNA in OC was up-regulated(P＜0.01);the number of OC and multinucleated OC increased(P＜0.01),bone TRAP activity was enhanced and BMD decreased(P＜0.01);(2)Compared with the TC group,the expression of CTSK mRNA and NFATc1 protein in the bones of the TS group was down-regulated(P＜0.05),and the expression of c-fos mRNA in the OC was down-regulated(P＜0.05);JAK2mRNA expression was up-regulated(P＜0.01),STAT3,NFATc1,CTSK,c-fos mRNA and NFATc1,CTSK,c-fos protein expression were all down-regulated(P＜0.05 or P＜0.01),TRAP,NFATc1,PU.1 in OC,C-fos and c-Src mRNA expression was down-regulated(P＜0.05 or P＜0.01),the number of OC and multinuclear OC decreased(P＜0.05 or P＜0.01),bone TRAP activity decreased,and BMD increased(P＜0.01).(3)Compared with the TS group,the expression of JAK2 mRNA in the bone of the TD group was up-regulated(P＜0.05),and the expression of STAT3,NFATc1,CTSK,c-fos mRNA and NFATc1,CTSK,and c-fos protein were all down-regulated(P＜0.05);OC mRNA expression of TRAP,NFATc1,PU.1,c-fos and c-Src was down-regulated(P＜0.05);the number of OC and multinucleated OC decreased(P＜0.05),bone TRAP activity decreased significantly,while BMD increased(P＜0.01).Conclusions:The ground reaction force generated by downhill running on the bone inhibits OC differentiation and bone resorption in T2DM mice through the JAK2/STAT3 pathway,and increases bone mass,while swimming has no obvious effect on the muscle traction force generated by the bone.
基金项目
中国博士后科学基金面上项目(2019M661957)
中国博士后科学基金面上项目(2021T140580)
扬州大学高端人才支持计划()
扬州大学"青蓝工程"项目()
维普
万方数据