矿化期小鼠牙胚中矿化相关因子的表达

Expression of mineral-associated factors in the mineral stage tooth germ of mice

目的:研究核心结合因子α1(corebindingfactoralpha1,Cbfα1)、骨桥素(osteopontin,OPN)、骨唾蛋白(bonesialoprotein,BSP)、骨钙素(osteocalcin,OC)和碱性磷酸酶(alkalinephosphatase,ALP)等调控矿化的相关因子在矿化期小鼠牙胚中的分布特点,探讨其在矿化期牙胚中的作用。方法:取出生后第5、7天的BALB/c小鼠30只,拉颈处死,分离解剖含下颌第一磨牙区的下颌骨,新鲜配制4%多聚甲醛固定过夜,常规石蜡包埋,近远中向5μm连续切片,采用免疫组化SABC法检测Cbfα1、OPN、BSP、ALP和OC等矿化相关因子在BALB/c小鼠矿化期牙胚中的表达及特点。结果:牙槽骨中可见Cbfα1、OPN和BSP表达;前期牙本质中有Cbfα1、ALP和OC表达;其余组织如牙囊细胞、牙髓细胞、中间层细胞、星网状层细胞、成牙本质细胞中仅见ALP和OC表达,且ALP在中间层细胞和牙髓细胞中呈强阳性表达;但在牙本质中均无表达。结论:牙发育相关的各硬组织,其形成的调控机制不同,分别由不同的矿化因子调控。Cbfα1、ALP和OC与牙本质的早期形成密切相关;Cbfα1、OPN和BSP参与牙槽骨的早期形成;ALP与中间层细胞的关系密切。这些因子对矿化的启动有重要作用。

PURPOSE： To study the distribution and expression of core binding factor alpha 1 （Cbfα1l）,bone sialoprotein （BSP）,osteopontin （OPN）,osteoealein （OC）and alkaline phosphatase（ALP）in mineral stage tooth germ of mice, so as to understand their roles in the development of the mineral stage tooth germ. METHODS： Thirty BALB/e mice in different days were killed, and their bilateral mandibular first molar germs with surrounding alveolar bone were taken out, then the tissues were fixed with 4% paraformaldebyde at 4℃ overnight, dehydrated, embedded in paraffin and serially sectioned at 5μm. Immunohistoehemieal assay was adopted to determine the tissue distribution and cellular localization of Cbfα1, OPN, BSP, ALP and OC in the mineral stage tooth germ by these sections of BALB/e mice. RESULTS：There were Cbfα1, BSP and OPN expressing in the alveolar bone, and Cbfα1, ALP, OC in predentin, while in other tissues such as dental follicle, pulp cells, stratum intermedium, stellate retieulum, only ALP and OC were detected, but none of them were observed in the dentin. CONCLUSIONS：The formation mechanisms of hard tooth tissues axe different. They axe controlled by different factors. Cbfα1,ALP and OC are involved in the early formation of dentin, while Cbfα1,OPN and BSP involved in the early formation of alveolar bone, ALP involved in the stratum intermedium. They all play an important role in the start of mineralization.Supported by National Natural Science Foundation of China （Grant No.30371537） and Award Fund for Excellent Young and Middle-Aged Scientists of Sbandong Province（Grant No.02BS096）.