Differential expression of the tight junction proteins, claudin-1, claudin-4, occludin, ZO-1, and PAR3, in the ameloblasts of rat upper incisors
Differential expression of the tight junction proteins, claudin-1, claudin-4, occludin, ZO-1, and PAR3, in the ameloblasts of rat upper incisors
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DOI：
10.1002/ar.20683
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发表时间：
2008-05-01
影响因子：
2
通讯作者：
Shibata, Yosaburo
中科院分区：
文献类型：
--
作者：
Inai, Tetsuichiro;Sengoku, Akihito;Shibata, Yosaburo
紧密连接（TJ）形成细胞旁渗透屏障，限制离子、小溶质和水的通过。成釉细胞是形成釉质的细胞，其依次分化为成釉细胞、分泌型成釉细胞、过渡型成釉细胞、皱褶型成釉细胞和光滑型成釉细胞。TJ位于成釉细胞的近端和远端。分泌型成釉细胞和RA远端的TJ是发育良好的闭合小带，但其他V是中等发育但不完整的闭合小带（ZO）或发育不全的闭合黄斑。我们在此研究了TJ蛋白，10个claudin亚型，occludin，ZO-1和PAR 3，细胞极性相关蛋白，在大鼠上切牙成釉细胞的免疫荧光定位。ZO-1和claudin-1在除SA远端外的所有成釉细胞的两端均有表达。Claudin 4和occludin在过渡期和成熟期成釉细胞的两端均有表达，但在SA的远端无表达。PAR 3在所有成釉细胞的近端TJ处均检测到，在早期RA的远端TJ处检测到微弱的PAR 3。这些结果表明，功能性闭锁小带形成于分泌性成釉细胞的远端，并且RA由不同的TJ蛋白组成。因此，分泌型成釉细胞和RA的远端Vs可能差异调节细胞旁通透性，以分别创造适合于釉质沉积和釉质成熟的微环境。此外，PAR 3可能主要参与近端而非远端TJ的形成和维持。
Tight junctions (TJs) create a paracellular permeability barrier to restrict the passage of ions, small solutes, and water. Ameloblasts are enamel-forming cells that sequentially differentiate into preameloblasts, secretory, transition, and ruffle-ended and smooth-ended maturation ameloblasts (RAs and SAs). TJs are located at the proximal and distal ends of ameloblasts. TJs at the distal ends of secretory ameloblasts and RAs are welldeveloped zonula occludens, but other Vs are moderately developed but incomplete zonula occludens (ZO) or less-developed macula occludens. We herein examined the immunofluorescence localization of TJ proteins, 10 claudin isoforms, occludin, ZO-1, and PAR3, a cell polarity-related protein, in ameloblasts of rat upper incisors. ZO-1 and claudin-1 were detected at both ends of all ameloblasts except for the distal ends of SAs. Claudin4 and occludin were detected at both ends of transition and maturation ameloblasts except for the distal ends of SAs. PAR3 was detected at the proximal TJs of all ameloblasts and faintly at the distal TJs of early RAs. These results indicate that functional zonula occludens formed at the distal ends of the secretory ameloblasts and RAs consisted of different TJ proteins. Therefore, the distal Vs of secretory ameloblasts and RAs may differentially regulate the paracellular permeability to create a microenvironment suitable for enamel deposition and enamel maturation, respectively. In addition, PAR3 may be principally involved in the formation and maintenance of the proximal, but not distal, TJs.