Kuboki Takuo, Kanyama Manabu, Nakanishi Tohru, Akiyama Kentaro, Nawachi Kumiko, Yatani Hirofumi, Yamashita Kazuo, Takano-Yamamoto Teruko, Takigawa Masaharu
Department of Oral and Maxillofacial Rehabilitation, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama 700-8525, Japan.
Arch Oral Biol. 2003 Jul;48(7):519-25. doi: 10.1016/s0003-9969(03)00088-8.
Healthy articular cartilage is thought to be maintained by the modulation of Cbfa1 expression, although little is currently known about Cbfa1 expression in such tissues. Therefore, we examined in vivo Cbfa1 transcript levels in the temporomandibular (TM) and knee joints of 3- and 10-week-old male ICR mice (weighing 50-70 g). A digoxigenin-11-UTP-labeled single-stranded RNA probe (0.6 kbp PstI-HindIII fragment of the 3' of untranslated region in exon 8 of mouse Cbfa1 cDNA) was prepared and in situ hybridization was performed on paraffin-embedded TM and knee joint sections. The antisense probe detected Cbfa1 transcripts in prehypertrophic chondrocytes, but not in the articular surface layer chondrocytes of 3- and 10-week-old mice TMJs. Despite the intense Cbfa1 expression in prehypertrophic chondrocytes, articular surface layer chondrocytes of the knee joints expressed low and undetectable level of Cbfa1 in the 3- and 10-week-old mice, respectively. These results indicate that Cbfa1 are highly expressed in the prehypertrophic chondrocytes presumably for articular tissue remodeling during the entire lifespan of the mouse, whereas Cbfa1 expression is suppressed in the articular surface chondrocytes in the adult mouse TM and knee joints to obtain the permanent cartilage phenotype.
健康的关节软骨被认为是通过Cbfa1表达的调节来维持的，尽管目前对Cbfa1在此类组织中的表达知之甚少。因此，我们检测了3周龄和10周龄雄性ICR小鼠（体重50 - 70克）颞下颌关节（TM）和膝关节中Cbfa1转录水平的体内情况。制备了地高辛素 - 11 - UTP标记的单链RNA探针（小鼠Cbfa1 cDNA第8外显子非翻译区3'端的0.6 kbp PstI - HindIII片段），并对石蜡包埋的TM和膝关节切片进行原位杂交。反义探针在3周龄和10周龄小鼠TMJ的前肥大软骨细胞中检测到Cbfa1转录本，但在关节表面层软骨细胞中未检测到。尽管前肥大软骨细胞中Cbfa1表达强烈，但在3周龄和10周龄小鼠的膝关节中，关节表面层软骨细胞分别表达低水平和不可检测水平的Cbfa1。这些结果表明，Cbfa1在小鼠整个生命周期中在前肥大软骨细胞中高度表达，可能用于关节组织重塑，而在成年小鼠TM和膝关节的关节表面软骨细胞中Cbfa1表达受到抑制，以获得永久软骨表型。
