下颌骨缺损修复过程中I型胶原基因表达的实验研究

目的了解生物材料和TGF--β1复合生物材料植入骨缺损区后细胞外基质内胶原基因表达的特点及其在骨愈合中的意义。方法采用SlotBlot杂交及苦味酸天狼星红－偏振光方法观察68只大鼠下颌骨缺损区骨修复过程中I型胶原mRNA表达及材料骨界面区I型胶原蛋白的分布。结果I型胶原的mRNA及其产物表达水平在三组之间有显著性差异，以TGF--β1组最高。结论本研究表明外源性TGF--β1通过促进I型胶原mRNA表达及其产物的合成，加快骨缺损的愈合；I型胶原mRNA可被认为是骨形成、骨改建的分子标记。

The Experimental Study onthe Gene Expession ofType- I Collagen in the Repair of Mandibular Defect in Rat

To detect the gene expression of extracellar matrix type I collagen caused by biomaterial and the influence of type I collagen gene expression to the healing pattems in different time points, single hydroxyapatit and hydroxyapatit combined with TGF- β 1 were implanted in the mandibular defect model and single defect was used for control. Methods:In this experiment, mandibular defects were established in SD rats(n = 68), divided into 3 groups. Hydroxyapatit (HA) combined with TGF - β 1 as a bone graft substitute was tested by slot blot hybridiztion to observe type I collagen mRNA and the distribution of Ⅰ collagen protein under sirius red stain-poplarizing light. Results: The protein and mRNA of I collagen existed statistical difference (P ＜ 0.05)in 3 groups. Conclusion: During the bone defect healing, there existed the I collagen mRNA increasing gradually. The study show TGF - β 1 promoting the bone healing process by the path of their corresponding collagen protein.