Smurf1抑制剂对失重性骨丢失的预防作用研究

Preventive effect of a Smurf1 inhibitor on microgravity-induced bone loss

目的探讨Smurf1小分子抑制剂A01对失重性骨丢失的预防作用。方法采用体外实验,以BMP-2刺激成骨细胞1 h,加入A01继续培养24 h,RT-PCR检测成骨基因表达水平。体内实验利用尾吊小鼠模拟失重性骨丢失,将24只C57BL/6J雄性小鼠随机分为假手术组(Sham)、尾吊组(HLU-Control)、尾吊给予A0150 mg/kg组(HLUA01-50)和100 mg/kg组(HLU-A01-100),治疗5周后通过影像学(micro-CT)、生物力学、组织学染色及基因表达水平检测,评估灌胃A01对小鼠骨丢失的预防及药物作用机制。结果体外结果显示,2和10μmol/L A01均可提高成骨基因碱性磷酸酶(ALP)、Ⅰ型胶原蛋白(Col-1α)和骨钙素(OCN)的表达水平。体内实验结果显示,A01防止HLU小鼠骨量的丢失,改善骨强度,增加骨矿化沉积率,防止骨小梁数量减少,提高骨组织成骨基因的表达水平。结论Smurf1小分子抑制剂A01通过促进骨形成,有效预防失重性骨丢失。

Objective To explore the preventive effect of Smurf1 small molecule inhibitor A01 on microgravity-induced bone loss.Methods In vitro experiment:after osteoblasts were stimulated with BMP-2 for 1 hour,A01 was added to be cultured for 24 hours,and the expression level of osteogenic genes was detected by RT-PCR.In vivo experiment:hindlimb unloading mice were used to simulate microgravity-induced bone loss.Twenty-four C57 BL/6 J male mice were randomly divided into sham operation group(Sham),hindlimb unloading group(HLU-Control),hindlimb unloading administration of A0150 mg/kg group(HLU-A01-50)and hindlimb unloading administration of A01100 mg/kg group(HLU-A01-100).After 5 weeks of treatment,the preventive effect and the mechanism of A01 on bone loss in mice was evaluated by microCT,biomechanics,histological staining and gene expression level detection.Results In vitro results showed that both2μmol/L and 10μmol/L A01 could enhance the expression levels of alkaline phosphatase(ALP),typeⅠcollagen(Col-1α)and osteocalcin(OCN)of osteogenic genes.The results of in vivo experiments showed that A01 was able to prevent the loss of bone mass,improve bone strength and mineral apposition rate,prevent the decrease in the number of bone trabeculae and increase the expression of osteogenic genes in bone tissue of HLU mice.Conclusion Smurf1 small molecule inhibitor A01 can effectively prevent microgravity-induced bone loss by promoting bone formation.