大鼠胚胎下颌磨牙发育初期p75NTR及RUNX2时空表达  

The Spatio-Temporal Expression of p75NTR and RUNX2 during Mandibular First Molar Tooth Germ Early Development in Rat

作　　者：刘畅[1] 杨琨[2] 李刚[2] 温秀杰[2] 赵曼竹 易青洁 唐明[1] 

机构地区：[1]重庆医科大学附属第一医院口腔科,重庆400016 [2]大坪医院野战外科研究所口腔科,重庆400042 [3]重庆医科大学附属口腔医院,重庆400015

出　　处：《基因组学与应用生物学》2017年第7期2640-2647,共8页Genomics and Applied Biology

基　　金：国家自然科学基金(81271097)资助

摘　　要：观察p75神经营养受体(p75 neurotrophin receptor,p75NTR)及Runt相关转录因子2(runt-related transcription factor 2,RUNX2)在SD大鼠下颌第一磨牙成牙发育初期不同发育阶段的表达分布情况,并探讨两者在SD大鼠出生后下颌第一磨牙发育矿化的作用。我们首先制备SD大鼠下颌第一磨牙发育初期标本(E13.5 d,E14.5 d,E15.5 d,E16.5 d,E18.5 d和P0.5 d),免疫组织化学检测p75NTR和RUNX2的表达分布情况。并用表达强度差异较大的天数P0.5 d的大鼠外胚间充质干细胞(ectomesenchymal stem cells,EMSC)进行体外矿化诱导,同时本实验采用蛋白质印迹法检测0 d、7 d、14 d和21 d的p75NTR和RUNX2的表达情况。我们发现p75NTR在蕾状期(E13.5 d)开始表达于成釉器旁边的间质;帽状期(E14.5 d,E15.5 d)广泛表达在内釉上皮、釉结、星网状层、牙乳头、牙囊;钟状期(E16.5 d,E18.5 d,P0.5 d)表达在内釉上皮、釉结、星网状层、中间层、牙乳头,牙囊。RUNX2在蕾状期、帽状初期(E13.5 d,E14.5 d)表达在成釉器下方间质;帽状末期(E15.5 d)达在在内釉上皮、釉结、星网状层、牙乳头、牙囊;钟状期(E16.5 d,E18.5 d,P0.5 d)表达在在内釉上皮、釉结、星网状层、中间层、牙乳头、牙囊;在帽状末期到钟状期(E15.5 d,E16.5 d,E18.5 d)RUNX2与p75NTR的表达范围和强度是相似的,但在钟状分化期(P0.5 d)RUNX2的表达范围类似于p75NTR但强度下降。P0.5 d EMSC蛋白质印迹法结果显示:随着矿化诱导时间的上升,p75NTR和RUNX2的表达均呈上升趋势。这些结果提示我们p75NTR和RUNX2在成牙初期不同天数表达位置及变化,具有时空特异性,可能与牙齿矿化发育相关,矿化诱导后变化趋势趋于一致说明二者在SD大鼠成牙发育初期下颌第一磨牙的发育及矿化中都起到一定的作用,可能存在正相关关系。This study aimed to observe the expressions distribution of p75 neurotrophin receptor （p75NTR） and Runt-related transcription factor 2 （RUNX2） in different developing stages of mandibular first molar of SD rats and discuss their effects in the development of mandibular first molar of SD rats aider the birth. We first preparedthe samples of mandibular first molar of SD rats in early developing stages （E 13.5 d, E 14.5 d, E 15.5 d, E 16.5 d, E 18.5 d, P0.5 d）, and the expressions and distributions of p75NTR and RUNX2 were detected by immunohistochemical method. Meanwhile, ectomesenchymal stem cells （EMSC） of SD rats at p0.5 day which had large differences in expression were used to induce mineralization in vitro, and the expressions and distributions ofp75NTR and RUNX2 at 0 day, 7 days, 14 days and 21 days were detected by Western blotting method. We found that p75NTR expressed in interstitial tissue near the enamel organ at the bud stage （E13.5 d）; it expressed in inner enamal epithelium, enamel knot, stellate reticulum, dental papilla, dental sac at the cap stage （E14.5 d and E15.5 d） and in inner enamal epithelium, enamel knot, stellate reticulum, stratum intermedium, dental papilla, and dental sac at the bell stage （E 16.5 d, E 18.5 d and P0.5 d）. RUNX2 was detected in interstitial tissue under the enamel organ at the bud stage and cap stage of initial morphogenesis （E13.5 d and E14.5 d）; while in inner enamal epithelium, enamel knot, stellate reticulum, dental papilla, and dental sac, it expressed at the end of the cap stage （El 5.5 d） and at the bell stage （E16.5 d, E18.5 d and P0.5 d）, it was in inner enamal epithelium, enamel knot, stellate retieulum, stratum intermedium, dental papilla, and dental sac. The expression range and intensity of RUNX2 were similar to p75NTR at the end of the cap stage and bell stage （E 15.5 d, E 16.5 d and E 18.5 d）, but the intensity of RUNX2 was reduced suddenly at the bell stage of differentiation （P0.5 d）. The results of P0.5d

关 键 词：P75NTR RUNX2 釉结 牙胚发育 

分 类 号：R78[医药卫生—口腔医学]