重组人BMP-2骨诱导中神经生长因子的表达

目的通过观察重组人骨形态发生蛋白-2(rhBMP-2)异位诱导成骨过程中神经生长因子(NGF)的表达，探讨NGF在BMP骨诱导中的作用。方法采用ICR小鼠48只，随机分为实验组和对照组，行右侧股后部肌袋异位成骨模型，实验组植入含0．125mg rhBMP-2胶原海绵复合物，对照组仅植入相同体积胶原海绵，分别于术后3、7、14、21d取材，进行放射学、组织学及免疫组化检测。结果放射学和组织学检测均证实，rhBMP-2胶原海绵复合物具有良好的诱导成骨能力；术后第7d，在软骨大量形成期，NGF阳性染色达到高峰．在成纤维细胞、软骨前体细胞、软骨细胞、肥大软骨细胞和成骨细胞中均有阳性表达；术后14、2ld，阳性细胞数量和染色强度有所回落。对照组未见成骨现象。结论首次证实在外源性BMP诱导成骨过程中有明显的NGF表达，提示NGF可能通过直接或间接的方式参与并协同BMP的诱导成骨过程。

Expression of Nerve Growth Factor During Osteoinduction of Recombined Human Bone Morphogenetic Protein-2

Objective To identify the expression of nerve growth factor (NGF) during bone induction by recombined human bone morphogenetic protein-2 (rhBMP-2) and discuss the possible role of NGF in the osteogenesis of BMP. Methods After a total of 48 ICR mice were divided into treated group and control group at random, 0.125 mg rhBMP-2/collagen sponge and collagen sponge alone were implanted respectively into the right thigh muscle pouches of each group. Tissues in the implanted site of the mice were removed on the 3rd, 7th, 14th and 21st day after implantation. Roentgenographic, histological and immunohistochemical analyses were performed to detect osteoinductive potentia of rhBMP-2/collagen sponge and the expression of NGF. Results RhBMP-2/collagen sponge displayed potent inducing ability to bone formation, while immunostaining for NGF was observed in the course of osteoinduction by rhBMP-2. Especially on the 7th day in the treated group, NGF positive immunostaining reached the peak in the stage of chondrogenesis and then a large number of cells expressing NGF, including fibroblasts, chondroblasts, chondrocytes, hypertrophic chondrocytes and osteoblasts, decreased in the number of positive cells and in intensity of immunostaining on the 14th and 21st day. Conclusion Many different kinds of cells induced by rhBMP-2 express NGF and it suggests that NGF may play an important role in osteogenesis initiated by exogenous BMP.