Yen E H, Pollit D J, Whyte W A, Suga D M
Orthodontic Section, Faculty of Dentistry, University of Manitoba, Winnipeg, Canada.
J Dent Res. 1990 Jan;69(1):26-30. doi: 10.1177/00220345900690010301.
The morphological and biochemical response of sutural fibroblasts in vitro to continuous force was examined. Cells from mouse interparietal sutures were grown and subcultured on glass slides. Titanium disks coated with collagen were allowed to attach to the cellular multilayers. Four of the glass slides were then placed at an angle of 75 degrees for a period of three days so that continuous stress would be created, while four others were left flat. Also, four glass slides were left flat with no disk. Following the incubation period, the dishes were labeled with 14C-glycine for 15 h. The cells and medium were then collected for collagen extraction followed by SDS-polyacrylamide gel electrophoresis. Dried gels impregnated with fluor were exposed to x-ray films that were then scanned densitometrically for collagen types I and III. It was found that the proportion of newly-synthesized type III collagen increased significantly with the application of continuous stress. A second set of experimental and control glass slides was fixed in glutaraldehyde and post-fixed in osmium tetroxide. Following critical-point drying and coating, the glass slides were examined under a scanning electron microscope. The scanning images showed the formation of a ligament-like structure between the disk and the glass slide. Moreover, mitotic activity, as evidenced by spheroidal cells, was stimulated in the areas previously adjacent to the disc, which had since moved away. This system offers a standardized continuous force system that can stress cells in a ligament-like structure and thus provides an in vitro model analogous to clinical orthodontic and orthopedic stress.
研究了体外培养的缝线成纤维细胞对持续力的形态学和生化反应。从小鼠顶间缝分离的细胞在载玻片上生长并传代培养。将涂有胶原蛋白的钛盘贴附于细胞多层培养物上。然后将其中四张载玻片以75度角放置三天，以产生持续应力，另外四张则保持平放。此外，还有四张载玻片不放置钛盘保持平放。孵育期结束后，用14C-甘氨酸标记培养皿15小时。然后收集细胞和培养基用于提取胶原蛋白，随后进行SDS-聚丙烯酰胺凝胶电泳。用荧光浸渍的干燥凝胶暴露于X光片，然后对X光片进行光密度扫描以检测I型和III型胶原蛋白。结果发现，施加持续应力后，新合成的III型胶原蛋白比例显著增加。第二组实验和对照载玻片用戊二醛固定，然后用四氧化锇后固定。经过临界点干燥和镀膜后，在扫描电子显微镜下观察载玻片。扫描图像显示在钛盘和载玻片之间形成了类似韧带的结构。此外，在先前与钛盘相邻但后来移开的区域，以球形细胞为证据的有丝分裂活性受到刺激。该系统提供了一个标准化的持续力系统，可对类似韧带结构中的细胞施加应力，从而提供一个类似于临床正畸和矫形应力的体外模型。
