牙周膜干细胞对脐血单个核细胞分化为破骨样细胞的影响

目的研究牙周组织改建过程中,牙周膜干细胞对破骨细胞形成的影响,初步探讨静压力和诱导因子对牙周膜干细胞调控破骨细胞形成的作用机制。方法有限稀释法克隆化培养牙周膜干细胞,密度梯度离心法分离脐血,收集单个核细胞。建立直接共培养和Transwell间接共培养体系。实验分组:A组,对照组(单纯共培养);B组,静压力组,共培养后第2天即对共培养细胞施加120 KPa压力,持续作用1 h后继续培养;C组,诱导因子组,培养液中加入诱导因子1,25二羟基维生素D3(1×10-8mol/L)和前列腺素E2(1×10-6mol/L)。采用倒置相差显微镜及TRAP染色,骨磨片染色等方法检测破骨样细胞(osteoclast-like cells,OLC)的形成及功能。结果各组第3、7天OLC计数比较结果显示,施加静压力后,直接共培养组OLC数量明显多于间接共培养组(P<0.01);而诱导因子组,直接共培养组OLC少于间接共培养组(P<0.01)。结论牙周膜干细胞能够促进脐血单个核细胞分化为破骨样细胞,且在静压力作用下,两种细胞直接接触时,这种调控作用更为明显。

Periodontal ligament stem cells improve peripheral blood mononuclear cells diffe-rentiation into osteoclast-like cells

Objective To investigate the effect of periodontal ligament stem cells(PDLSCs) on osteoclasts differentiation during periodontal remodeling in order to elucidate the roles of static force and inducible factors in the regulation of osteoclasts differentiation by PDLSCs.Methods PDLSCs were isolated and cultured from freshly extract teeth by using the limiting dilution technique.Mononuclear cells of umbilical cord blood(UBMC) were separated by density gradient centrifugation.After identification,the two kinds of cells were co-cultured in direct-and in Transwell co-culture system.The co-culture system were further treated by static force(120 kPa for 1 h per day,for 3 d),or inducible factors(1×10-8 mol/L α-25(OH)2D3 and 1×10-6 mol/L PGE2 for 7 d) to induce osteoclast-like cells(OLC).The cells without treatment served as control.Cell morphology was observed by phase contrast microscopy.TRAP staining was used to identify the OLCs.And the bone-resorption capacity was assessed by lacunae forming ability on bone slice.Results Under static force,there were more OLCs in direct co-culture system than in the Transwell co-culture system(P<0.01).While,the treatment of inducible factors resulted more OLCs in the Transwell co-culture system than in direct co-culture system(P<0.01).Conclusion PDLSCs promote mononuclear cells differentiate into OLC,especially under the continuous static force and the two cells contact directly.