重组人骨形成蛋白2对下颌骨牵引成骨中整合素β_1表达的影响

背景:骨组织中整合素表达水平可影响细胞功能,调控成骨和骨吸收,但整合索只有被其他因于激活后才能发挥强大的黏附作用,重组人骨形成蛋白2具有此作用吗?目的:观察不同质量重组人骨形成蛋白2对兔下颌骨牵引成骨区整合素B_1的表达影响.设计、时间及地点:随机分组动物实验,组织学观察,于2006-05/2007-05在辽宁医学院动物实验中心和免疫组化中心完成.材料:日本成年大耳白兔45只.重组人骨形成蛋白2由北京军事医学科学院三所八室提供.方法:选用日本成年大耳白兔45只建立下颌骨牵引模型,造模后采用随机数表法将分为3组:空白对照组、1.5,3.0 mg重组人骨形成蛋白2胶原海绵载体组,15只/组.分别将不含重组人骨形成蛋白2胶原海绵载体、含1.5,3.0 mg重组人骨形成蛋白胶原复合物植入3组兔下颌骨切开处,固定、牵引0.4 mm/次,2次/d,共计5 d,总延长下颌骨4 mm.主要观察指标:牵引后稳定期第1,3,7,14,28天取牵引区新生骨痂行免疫组织化学染色观察骨组织中整合素β_1的表达.结果:45只日本大耳白兔均建模成功,进入结果分析.整合素β_1在牵引区表达主要反映在牵引7 d后.在同一时间内,随着重组人骨形成蛋白2质量的增加,整合素β_1阳性细胞表达率、阳性面积百分比逐渐增多(P<0.05):在同一质量下,随着时间的延长,整合素β_1阳性细胞阳性表达率、阳性面积百分比逐渐上升(P<0.05).结论:局部应用外源性重组人骨形成蛋白2在牵引成骨中晚期对整合素β_1的表达有促进作用,并且整合素β_1的表达对重组人骨形成蛋白2呈质量依赖性.

Effects of recombinant human bone morphogenetic protein 2 on integrin beta 1 expression during mandibular distraction

BACKGROUND:Integfin levels can affect cellular function,regulate bone formation and bone resorption.However,this process need activated by other factors,whether recombinant human bone morphogenetic protein 2 (rhBMP-2)has this effect is poorly understood.OBJECTIVE:To study the effects of the different concentration of rhBMP-2 on the expression of inergrin β_1 during the mandibular dfScraction in rabbits.DESIGN,TIME AND SETTING:The randomized,controlled.animal grouping experiment of histological observation was performed at the Animal ExperimentaI Center and Immunohistochemistry Center of Liaoning Medical University from May 2006 to May 2007.MATERIALS:A total of 45 Japanese white rabbits were used.rhBMP-2 was supplied by Beijing Academy of Military Medical Sciences.METHODS:The rabbits were prepared for mandibular distraction models and randomly assigned into control,1.5 mg rhBMP-2 and 3.0 mg rhBMP-2 groups.with 15 animals in each group.Collagen sponge and collagen binding proteins were implanted into mandibles of rabbits,respectively,and distraction 0.4 mm per time,twice per day for 5 days.The mandibles were lengthened 4 mm.MAIN OUTCOME MEASURES:The expression of integrin 131 was detected using immunohistochemistry at days 1,3,7,14,and 28 after distraction.RESULTS:All rabbits were included in the final analysis.The integdn β_1 mainly expressed at 7 days after distraction.At the same time point.when concenrtation rhBMP-2 was increased,the positive integrin β_1 rate and positive stained area percentage were increased(P<0.05).Compared to the same concentration,the positive integrin β_1 rate and positive stained area percentage were gradually increased as time prolonged (P<0.05).CONCLUSION:The integdn β_1 expression can be promoted by rhBMP-2 at the anaphase of mandibular distraction osteogenesis in a concentration-dependent manner.