缺氧与加力在正畸骨吸收作用中的细胞学研究

Cell study of the effects of hypoxia and force on orthodontic bone resorption

目的 观察缺氧对正畸压力侧破骨细胞形成的影响,探讨缺氧、加力在正畸骨改建中各自所起的作用,并分析其在破骨细胞形成过程中的相互作用关系.方法 建立人牙周膜细胞与外周血单个核细胞接触式共培养模型,模拟正畸缺氧、加力、缺氧＋加力,不同条件作用1、3、6h后培养3d,TRAP染色检测破骨样细胞的形成.Reahime PCR检测骨改建相关因子HIF-1α 、IL-1β、RANKL、OPGmRNA的表达并计算RANKL/OPG比值.结果 TRAP染色阳性细胞在缺氧＋加力组各个处理时间段都有出现,缺氧组则在处理3、6h中出现,加力组仅在处理6h中出现,且缺氧＋加力组的阳性细胞数目均大于单独缺氧、加力组.HIF-1α、IL-1β、RANKL、OPGmRNA的表达及RANKL/OPG比值都呈现出缺氧＋加力组均大于单纯缺氧、加力组.结论 缺氧和加力分别可以诱导与人牙周膜细胞共培养的单个核细胞向破骨细胞分化,缺氧和加力相互协同、共同促进正畸牙齿移动过程中骨吸收的发生.

Objective To observe the influence of hypoxia on osteoclast formation at orthodontic compressive side,to discuss the roles of hypoxia and static pressure in orthodontic bone remolding,and to analyse their interrelationships and interactions in osteoclast development.Methods A co-culture system of human periodontal ligament cells （HPDLCs） and peripheral blood monocytes （PBMC） was established.Under three different treatment conditions of hypoxia and/or load,we divided co-culture cells into four groups,including one control group and three experimental groups （hypoxia＋load group,hypoxia group and load group）.Each group was treated for 1 h,3 h,6 h,and then cultured 3 days in CO2 incubator.After that,TRAP staining was operated to observe the osteoclast development.By Realtime PCR,we observed the HIF-1α、IL1β、RANKL and OPG expression and ratio of RANKL/OPG of co culture system under hypoxia and/or load.Results TRAP positive cells were found in all three time points of hypoxia＋load group,3 h and 6h of hypoxia group,6 h of load group,but none in control group,and the number of positive cells of hypoxia＋load group is larger than hypoxia group and load group.The HIF-1α、IL-1β、RANKL and OPG expression and ratio of RANKL/OPG in hypoxia＋ load group was obviously higher than that of hypoxia group and load group.Conclusions Either hypoxia or static pressure could induce PBMC co-cultured with HPDLCs differentiate to osteoclast.Hypoxia and static pressure can work in synergism to promote theorthodontic bone resorption.