Akimoto Yoshihiro, Yamakawa Naomi, Furukawa Kiyoshi, Kimata Koji, Kawakami Hayato, Hirano Hiroshi
Department of Anatomy, Kyorin University School of Medicine, Tokyo, Japan.
J Histochem Cytochem. 2002 Jun;50(6):851-62. doi: 10.1177/002215540205000611.
The expression and distribution of the long form of Type XII collagen were investigated histochemically during chicken corneal development using a monoclonal antibody (P3D11) raised against the N-terminal domain of chicken Type XII collagen. Specificity of the antibody was confirmed by immunoprecipitation before and after bacterial collagenase digestion. Immunofluorescent microscopic studies showed that during chicken cornea formation, the long form of Type XII collagen is initially detected on Day 3 embryo (stage 19) in the sub-epithelial matrix of the corneal periphery and in the matrix around the optic cup. On Day 5 embryo (stage 27) the long form was expressed in the primary stroma. Thereafter, as the secondary stroma was formed, the long form localized in the sub-epithelial and sub-endothelial matrices and in the anterior region of the limbus (corneoscleral junction) before the formation of Descemet's and Bowman's membranes. After hatching, the immunoreactivity decreased predominantly in the sub-epithelial and sub-endothelial matrices but remained at the anterior region of the limbus. Immunoelectron microscopic examination demonstrated that the long form localizes in the Descemet's and Bowman's membranes and along the collagen fibrils in the stroma with a periodic repeat. Based on the distribution of the long form of Type XII collagen in the sub-epithelial and sub-endothelial matrices and limbus, it was suggested that the long form of Type XII collagen is involved in formation of the Descemet's and Bowman's membranes and in stabilization of the limbus.
利用针对鸡XII型胶原蛋白N端结构域产生的单克隆抗体（P3D11），通过组织化学方法研究了鸡角膜发育过程中XII型胶原蛋白长链的表达和分布情况。在细菌胶原酶消化前后，通过免疫沉淀法证实了该抗体的特异性。免疫荧光显微镜研究表明，在鸡角膜形成过程中，XII型胶原蛋白长链最初在胚胎第3天（第19阶段）于角膜周边的上皮下基质和视杯周围的基质中被检测到。在胚胎第5天（第27阶段），长链在初级基质中表达。此后，随着次级基质的形成，在Descemet膜和Bowman膜形成之前，长链定位于上皮下和内皮基质以及角膜缘（角膜巩膜交界处）的前部区域。孵化后，免疫反应性主要在上皮下和内皮基质中降低，但在角膜缘前部区域仍保留。免疫电子显微镜检查表明，长链定位于Descemet膜和Bowman膜以及基质中具有周期性重复的胶原纤维上。基于XII型胶原蛋白长链在上皮下和内皮基质以及角膜缘中的分布情况，提示XII型胶原蛋白长链参与Descemet膜和Bowman膜的形成以及角膜缘的稳定。
