Ngo Thai Q, Scherer Michaela A, Zhou Fiona H, Foster Bruce K, Xian Cory J
Department of Orthopaedic Surgery, Women's and Children's Hospital, 72 King William Road, North Adelaide, SA 5006 Australia.
J Histochem Cytochem. 2006 Aug;54(8):945-54. doi: 10.1369/jhc.6A6939.2006. Epub 2006 May 1.
The injured growth plate cartilage is often repaired by bony tissue, resulting in impaired bone growth in children. Bone morphogenic proteins (BMPs) are important for bone fracture repair, and as a step to characterize potential involvement of BMPs in bony repair of injured growth plate, expression of BMPs and receptors (BMP-R) was examined by quantitative RT-PCR and immunohistochemistry in rat injured tibial growth plate. During the inflammatory response on day 1, slightly increased expression of BMP-3, BMP-4, BMP-R1a, and BMP-R2 was observed, with immunostaining seen among inflammatory cells at the injury site. During mesenchymal infiltration and osteogenic responses on days 3-14, moderately increased expression of BMP-2, -3, -4, -7, and BMP-R1a was found, with immunostaining observed among infiltrated mesenchymal cells and differentiated osteoblasts lining bony trabeculae. During maturation phase on days 14-25, only BMP-7 was seen upregulated slightly and was localized in osteoblasts and marrow cells at the injury site. The temporospatial expression of BMPs and receptors at the injured growth plate suggests potential involvement of BMP-3 and -4 in regulating the inflammatory response or as its mediators in modulating downstream events, and BMP-2, -3, -4, and -7 in the fibrogenic and osteogenic responses, and BMP-7 in bone remodeling at the injured growth plate.
受损的生长板软骨常由骨组织修复，导致儿童骨骼生长受损。骨形态发生蛋白（BMPs）对骨折修复很重要，作为表征BMPs可能参与受损生长板骨修复的一个步骤，通过定量逆转录聚合酶链反应（RT-PCR）和免疫组织化学检测了大鼠受伤胫骨生长板中BMPs及其受体（BMP-R）的表达。在第1天的炎症反应期间，观察到BMP-3、BMP-4、BMP-R1a和BMP-R2的表达略有增加，在损伤部位的炎症细胞中可见免疫染色。在第3至14天的间充质浸润和成骨反应期间，发现BMP-2、-3、-4、-7和BMP-R1a的表达适度增加，在浸润的间充质细胞和排列在骨小梁上的分化成骨细胞中观察到免疫染色。在第14至25天的成熟阶段，仅见BMP-7略有上调，且定位于损伤部位的成骨细胞和骨髓细胞中。生长板损伤处BMPs及其受体的时空表达表明，BMP-3和-4可能参与调节炎症反应或作为其调节下游事件的介质，BMP-2、-3、-4和-7参与纤维生成和成骨反应，而BMP-7参与损伤生长板的骨重塑。
