血管束、感觉神经束植入组织工程骨降钙素基因相关肽和受体的时空分布

目的 探讨单纯血管束、感觉神经束分别植入组织工程骨修复兔骨缺损对降钙素基因相关肽(CGRP)及受体(CGRPR-1)表达的影响.方法 54只新西兰兔按随机数字表法分为三组(n=18):感觉神经束植入组(A组)、血管束植入组(B组)、单纯组织工程骨对照组(C组),于术后4、8、12周分别处死18只动物,对修复骨段行Masson染色观察骨形成与改建过程,同时行免疫组化染色检测修复骨段内CGRP及CGRPR-1的表达,并提取总RNA行Real-time PCR检测CGRP及CGRPR-1的表达情况.结果 各时间点A组和B组CGRP、CGRPR-1 mRNA的表达均高于C组,且A组表达高于B组,差异均有统计学意义(P<0.05);随时间延长,组织工程骨内CGRP及CGRPR-1 mRNA呈先增高后逐渐降低趋势,8周时mRNA高于4周和12周,4周时mRNA在3个检测时间点中最低,差异均有统计学意义(P<0.05);组织工程骨内新生骨质边缘、骨膜、血管周围均有CGRP阳性表达,分布均匀;CGRPR-1于成骨细胞周围表达较多.结论 植入感觉神经柬和血管束均能促进神经肽分泌,植入血管束分泌更多.

Temporal and spatial distribution of calcitonin gene related peptide and its receptor in tissue-engineered bone

Objective To explore whether the respective implantation of vascular bundles and sensory nerve tracts into a tissue-engineered bone will affect the expression of CGRP (Calcitonin gene related peptide) and its receptor. Methods Fifty-four New Zealand rabbits were randomly divided into 3 even groups for implantation of sensory nerve tracts (group A),implantation of vascular bundles (group B),and a control group of simple tissue-engineered bone (group C) . Animals were sacrificed 4,8,12 weeks after implantation,respectively. Masson staining was conducted to observe the process of bone formation and re-molding. CGRP and CGRPR-1 expressions in the new bone were measured by immunohistochemistry and Real-time PCR at 4,8 and 12 weeks after implantation. Results At all time points,the CGRP and CGRPR-1 expressions in groups A and B were significantly higher than in group C (P<0.05),and those in group A were higher than in group B too (P<0.05) . Over time,the expressions of CGRP and CGRPR-1 mRNA in each group in the new bone tissue were gradually reduced after an initial increase. The neuropeptide expression at the 8th week was higher than those at the 4th and 12th weeks. The neuropeptide expression at the 4th week was the lowest. The expression of CGRP was mainly localized in the periphery of newly generated bone,periosteum and the blood vessels. The expression of CGRPR-1 was mainly localized in the periphery of osteoblasts. Conclusions Implantation of either vascular bundles or sensory nerve tracts can promote neuropeptide secretion. The vascular bundle implantation may result in higher expressions of CGRP and CGRPR-1 than sensory nerve tract implantation.