局部注射不同剂量抗RANKL抗体对大鼠牙槽骨骨质疏松的影响

Effects of Local Injection of Different Doses of Anti-RANKL Antibody on Alveolar Bone Osteoporosis in Rats.

目的:探究局部注射抗核因子κB受体活化因子配体(receptor activator of nuclear factor kappa-B ligand,RANKL)抗体对大鼠牙槽骨骨质疏松的影响及不同剂量间的比较研究。方法:采用SD大鼠30只(对照组9只,实验组21只),通过皮下注射地塞米松建立大鼠牙槽骨骨质疏松模型,建模5周后进行模型验证,模型验证成功后,将实验组随机分为3组;实验组Ⅱ、Ⅲ于1、3、7 d在大鼠右上第一磨牙腭侧黏骨膜下注射兔抗大鼠RANKL抗体0.1μg/位点和1μg/位点,实验组Ⅰ注射等体积生理盐水。1周后处死取材,采用微计算机断层扫描技术(micro computed tomography,Micro-CT)测量右上第一磨牙区牙槽骨骨密度(bone mineral density,BMD)、骨体积分数(bone volume fraction,BV/TV);牙槽骨组织病理学染色观察组织形态学改变及破骨细胞数目变化;酶联免疫吸附试验(enzyme linked immunosorbent assay,ELISA)检测牙龈中RANKL/骨保护素(osteoprotegerin,OPG)比值变化。结果:成功建立大鼠牙槽骨骨质疏松模型。Micro-CT和组织病理学结果显示,注射RANKL抗体后,牙槽骨BMD、BV/TV增加,破骨细胞数目减少,成骨细胞活跃,骨髓腔减小,但高、低剂量抗体相比变化不显著;ELISA结果显示,注射高剂量抗体后牙龈中RANKL/OPG比值显著降低,注射低剂量抗体后RANKL/OPG比值虽降低,但变化不显著。结论:局部注射抗RANKL抗体可以改善大鼠牙槽骨骨质疏松,低剂量即可达到改善效果。

Objective:To explore the effect of local injection of different doses of anti-receptor activator of nuclear factor kappa-B ligand(RANKL)antibody on alveolar bone osteoporosis in rats.Methods:A total of 30 SD rats were selected,with 9 in the control group and 21 in the experimental group.The rat alveolar bone osteoporosis model was established by subcutaneous injection of dexamethasone.The model was verified 5 weeks later.After successful verification,the experimental group was randomly divided into 3 groups.Experimental groupⅡandⅢwere injected with 0.1μg/site and 1μg/site of rabbit anti-rat RANKL antibody in the palatine side of the upper right first molar of rats on day 1,3,and 7,and experimental groupⅠwas injected with equal volume of saline.Bone mineral density(BMD)and bone volume fraction(BV/TV)of alveolar bone in the right upper first molar region were measured by micro-CT after 1 week.The changes of histomorphology and the number of osteoclasts were observed by histopathological staining of alveolar bone.Enzyme linked immunosorbent assay(ELISA)was used to detect the RANKL/osteoprotegerin(OPG)ratio in gingival tissue.Results:The rat alveolar bone osteoporosis model was established successfully.Micro-CT and histopathology showed that after antibody injection,alveolar bone BMD and BV/TV were increased,the number of osteoclasts were decreased,osteoblasts were actived,and bone marrow cavity were decreased,but there was no significant change between high and low doses of antibody.ELISA results showed that the ratio of RANKL/OPG in gingival was significantly decreased after high dose antibody injection,however,it was decreased without significance after low dose antibody injection.Conclusion:Local injection of anti-RANKL antibody can improve the alveolar bone osteoporosis in rats,and low dose could reach the improvement effect.