Shandong Provincial Key Laboratory of Oral Biomedicine, School and Hospital of Stomatology, Shandong University, 44-1 Wenhuaxi Road, Jinan, 250012 Shandong, People's Republic of China.
J Mol Histol. 2012 Jun;43(3):289-95. doi: 10.1007/s10735-012-9409-z. Epub 2012 Mar 30.
Four and a half LIM domains 2 (FHL2) functions as a transcriptional co-activator or co-repressor in a cell-type-specific manner. As a positive regulator, FHL2 plays an important role in osteoblast differentiation and bone formation. Our previous study showed that FHL2 was expressed in odontoblasts in mature human teeth under normal and pathological conditions. The purpose of this study was to investigate the spatial-temporal expression patterns of FHL2 at different stages of mouse molar development by immunohistochemistry. Our results showed that at the bud and cap stage, FHL2 was expressed both in enamel organ and the underlying mesenchyme. At the early bell stage, FHL2 appeared in the inner and outer enamel epithelium, stratum intermedium and the secondary enamel knot. Positive staining gradually converged at the cusps of dental papilla. At the late bell stage, FHL2 was expressed in the terminal differentiated ameloblasts and odontoblasts and stratum intermedium. At the postnatal day, FHL2 was detected in the secretory and mature ameloblasts and odontoblasts and mature enamel, and gradually appeared at Hertwig's epithelial root sheath and periodontal tissues. The spatial-temporal expression patterns of FHL2 from the bud stage to the postnatal day (13.5) suggested that during tooth development, FHL2 might play an important role in ameloblast and odontoblast differentiation, secretion of enamel and dentin matrix, mineralization of enamel, molar crown morphogenesis, as well as root formation.
四个半 LIM 结构域 2（FHL2）以细胞类型特异性方式作为转录共激活子或共抑制子发挥作用。作为正向调节因子，FHL2 在成骨细胞分化和骨形成中发挥重要作用。我们之前的研究表明，FHL2 在正常和病理条件下成熟人牙的成牙本质细胞中表达。本研究旨在通过免疫组织化学方法研究 FHL2 在小鼠磨牙发育不同阶段的时空表达模式。结果显示，在芽和帽状期，FHL2 在釉器和其下方的间充质中均有表达。在早期钟状期，FHL2 出现在内釉上皮和外釉上皮、中间层和次生釉结中。阳性染色逐渐汇聚在牙乳头的尖部。在晚期钟状期，FHL2 表达于终末分化的成釉细胞和成牙本质细胞和中间层。在出生后第 13.5 天，FHL2 检测到在分泌期和成熟的成釉细胞和成牙本质细胞以及成熟釉质中，并且逐渐出现在 Hertwig 上皮根鞘和牙周组织中。从芽状期到出生后第 13.5 天的 FHL2 时空表达模式表明，在牙齿发育过程中，FHL2 可能在成釉细胞和成牙本质细胞分化、釉质和牙本质基质分泌、釉质矿化、磨牙冠形态发生以及牙根形成中发挥重要作用。
