MacNeil R L, Berry J E, Strayhorn C L, Shigeyama Y, Somerman M J
Department of Periodontics/Prevention/Geriatrics, School of Dentistry, University of Michigan, Ann Arbor 48109-1078, USA.
Arch Oral Biol. 1998 Oct;43(10):779-87. doi: 10.1016/s0003-9969(98)00054-5.
The purpose (of this study) was to determine the temporal and spatial pattern of type XII collagen expression during murine tooth/root development. Using in situ hybridization techniques, expression of type XII collagen was compared with that of type I collagen, the most abundant collagen in periodontal tissues. Mouse first mandibular molars were examined at the following developmental periods: pre-root formation, early root formation, initial alignment of the periodontal ligament (PDL) fibres, and PDL maturation as the tooth erupted and attained occlusal function. Transcripts for type I collagen were identified in bone cells and odontoblasts at all times but not in the dental follicle before root formation. As root formation progressed, type I collagen expression became apparent within cells of the dental follicle and forming PDL. During early stages of tooth development, signal for type XII collagen was not observed in any cells/tissues. Type XII collagen expression was first detected in the dental follicle/PDL region during tooth eruption and increased in the PDL as the molar tooth erupted into the mouth and achieved occlusal contact. These findings suggest that type XII expression is timed with the alignment and organization of PDL fibres and is limited in tooth development to cells within the periodontal ligament.
本研究的目的是确定小鼠牙齿/牙根发育过程中Ⅻ型胶原表达的时空模式。运用原位杂交技术，将Ⅻ型胶原的表达与牙周组织中最丰富的胶原——Ⅰ型胶原的表达进行比较。在以下发育阶段对小鼠第一下颌磨牙进行检查：牙根形成前期、牙根形成早期、牙周韧带（PDL）纤维的初始排列期，以及随着牙齿萌出并获得咬合功能时的PDL成熟期。Ⅰ型胶原转录本在所有时间均在骨细胞和成牙本质细胞中被鉴定出，但在牙根形成前的牙囊细胞中未被发现。随着牙根形成的进展，Ⅰ型胶原在牙囊细胞和正在形成的PDL细胞中表达明显。在牙齿发育的早期阶段，在任何细胞/组织中均未观察到Ⅻ型胶原信号。Ⅻ型胶原表达首次在牙齿萌出期间的牙囊/PDL区域被检测到，并随着磨牙萌出进入口腔并实现咬合接触而在PDL中增加。这些发现表明，Ⅻ型胶原的表达与PDL纤维的排列和组织同步，并且在牙齿发育过程中局限于牙周韧带内的细胞。
