Poole C A, Gilbert R T, Herbage D, Hartmann D J
Department of Anatomy, Faculty of Medicine and Health Sciences, University of Auckland, New Zealand.
Osteoarthritis Cartilage. 1997 May;5(3):191-204. doi: 10.1016/s1063-4584(97)80014-3.
The pericellular localization of type IX collagen in avian and mammalian hyaline cartilages remains controversial, while its distribution during osteoarthritic degeneration is poorly understood. This study aimed to compare and contrast the immunohistochemical distribution of type IX collagen in normal mature and spontaneously osteoarthritic canine tibial cartilage.
Thick vibratome sectioning techniques were evaluated and compared with isolated chondrons using a range of streptavidin-linked probes in combination with light, confocal and transmission electron microscopy.
In normal intact samples, type IX collagen was concentrated in the pericellular microenvironment, while a weaker extracellular reaction around each chondron separated the territorial matrix from the unstained interterritorial matrix. Further differentiation was evident in isolated chondrons where the fibrous pericellular capsule stained more intensely than the tail and interconnecting segments between columnated chondrons. Two regions of type IX reactivity were identified in osteoarthritic tissue: an intensely stained superficial reactive region below the eroding margins, and normal deep layer cartilage where pericellular staining persists. The superficial reactive region was characterized by chondron swelling and chondrocyte cluster formation, a loss of pericellular type IX staining, and a significant increase in matrix staining between clusters. Disintegration and loss of fibrillar collagens was evident in both the swollen microenvironment and adjacent territorial matrices.
The results suggest that changes in type IX distribution, expansion of the pericellular microenvironment and chondrocyte proliferation represent key elements in the chondron remodeling and chondrocyte cluster formation associated with osteoarthritic degeneration.
IX型胶原蛋白在鸟类和哺乳动物透明软骨中的细胞周围定位仍存在争议，而其在骨关节炎退变过程中的分布情况却知之甚少。本研究旨在比较和对比IX型胶原蛋白在正常成熟和自发性骨关节炎犬胫骨软骨中的免疫组织化学分布。
使用一系列与链霉亲和素相连的探针，结合光学显微镜、共聚焦显微镜和透射电子显微镜，对厚振动切片技术进行评估，并与分离的软骨细胞进行比较。
在正常完整样本中，IX型胶原蛋白集中在细胞周围微环境中，而每个软骨细胞周围较弱的细胞外反应将区域基质与未染色的区域间基质分隔开来。在分离的软骨细胞中，进一步的分化很明显，其中纤维状细胞周围囊膜的染色比尾部和柱状软骨细胞之间的连接段更强烈。在骨关节炎组织中鉴定出两个IX型反应区域：侵蚀边缘下方强烈染色的浅表反应区域，以及细胞周围染色持续存在的正常深层软骨。浅表反应区域的特征是软骨细胞肿胀和软骨细胞簇形成、细胞周围IX型染色缺失以及簇间基质染色显著增加。在肿胀的微环境和相邻的区域基质中，纤维状胶原蛋白的崩解和丢失都很明显。
结果表明，IX型分布的变化、细胞周围微环境的扩张和软骨细胞增殖是与骨关节炎退变相关的软骨细胞重塑和软骨细胞簇形成的关键因素。
