Maurin Jean-Christophe, Couble Marie-Lise, Staquet Marie-Jeanne, Carrouel Florence, About Imad, Avila Jesús, Magloire Henry, Bleicher Françoise
University of Lyon, Lyon, France.
J Endod. 2009 Jul;35(7):992-6. doi: 10.1016/j.joen.2009.04.009.
Map-1B belongs to the family of proteins that govern the dynamic state and organization of microtubules within cells. MAP-1B is a microtubule-associated protein highly expressed during the development of the nervous system. Its expression, regulated by the fragile X mental retardation protein (FMRP), is essential to stabilize microtubules during the elongation of dendrites and neurites. Other microtubules-associated molecules such as tau or MAP2 seem to act similarly. The aim of this work was to identify the MAP-1B expression in in vitro and in vivo human odontoblasts during development and carious processes. The expression of MAP2 and tau was also studied.
In cultured cells, MAP-1B expression was analyzed by real-time polymerase chain reaction, flow cytometry, and Western blot. Its distribution was visualized by in situ hybridization and immunochemistry both in vitro and in vivo. The expression of FMRP, MAP2, and tau was identified by real-time polymerase chain reaction and immunochemistry.
MAP-1B is specifically expressed in odontoblasts from adult third molars as well as incisor germs from human embryos. In adult carious teeth, it is also expressed in newly differentiated dentin-forming cells. In vitro, MAP-1B expression is related to the differentiation state of odontoblasts. MAP-1B clearly underlines the cellular architecture of cell bodies and processes of differentiated cells. FMRP, MAP2, and tau are also detected in vivo.
On the basis of these data, MAP-1B could be considered as a new protein involved in the terminal differentiation of odontoblasts.
Map-1B属于调控细胞内微管动态状态和组织的蛋白质家族。MAP-1B是一种在神经系统发育过程中高度表达的微管相关蛋白。其表达受脆性X智力低下蛋白（FMRP）调控，对于在树突和神经突伸长过程中稳定微管至关重要。其他微管相关分子如tau或MAP2似乎也有类似作用。本研究旨在确定发育和龋病过程中体外及体内人成牙本质细胞中MAP-1B的表达情况。同时也研究了MAP2和tau的表达。
在培养细胞中，通过实时聚合酶链反应、流式细胞术和蛋白质免疫印迹法分析MAP-1B的表达。通过体外和体内原位杂交及免疫化学观察其分布。通过实时聚合酶链反应和免疫化学鉴定FMRP、MAP2和tau的表达。
MAP-1B在成人第三磨牙的成牙本质细胞以及人类胚胎的切牙胚中特异性表达。在成人龋病牙中，它也在新分化的形成牙本质细胞中表达。在体外，MAP-1B的表达与成牙本质细胞的分化状态相关。MAP-1B清晰地勾勒出分化细胞的细胞体和突起的细胞结构。体内也检测到了FMRP、MAP2和tau。
基于这些数据，MAP-1B可被视为参与成牙本质细胞终末分化的一种新蛋白。
