Establishment of rat models of brain injury combined with femoral closed fracture: expression of calcitonin gene-related peptide and insulin-like growth factor 1 in bone callus

doi:10.3969/j.issn.2095-4344.2015.05.001

Abstract

Abstract:

BACKGROUND: The operation time for patients with craniocerebral injury with the lower limb fracture is not conclusive, and the mechanisms associated with the early healing of the fractures after traumatic brain injury remains to be clarified. At present, there are few animals models of brain injury combined with femoral closure fracture, and therefore, a stable animal model is needed for clinical studies.
OBJECTIVE: To establish stable rat models of brain injury combined with femoral closure fracture, to investigate the expression of calcitonin gene-related peptide and insulin-like growth factor 1 in bone callus during the healing process of femoral fracture, and to analyze the mechanism of brain injury on fracture healing.
METHODS: Forty-eight male Sprague-Dawley rats were randomly divided into two groups, in which the models of brain injury combined with femoral fracture and models of femoral fracture were established, respectively. Each group contained 24 rats. Rats were killed at 7, 14, 28 days after injury, a 10 mm femoral callus around the fracture site was cut. The femoral callus specimens were detected with hematoxylin-eosin staining and immunohistochemistry method. The dynamic changes of calcitonin gene-related peptide and insulin-like growth factor 1 expression were observed.
RESULTS AND CONCLUSION: The immunohistochemistry results showed that, the absorbance of calcitonin gene-related peptide positive expression and the percentage of insulin-like growth factor 1 positive cells in bone callus of rats with brain injury and femoral fracture showed significant differences compared with the femoral fracture group at 7 and 14 days (P < 0.05). The difference was not significant between the two groups at 28 days. The intragroup comparison results found significant difference in the brain injury and femoral fracture group (P < 0.05), and no significant difference in the femoral fracture group (P > 0.05). The expression of calcitonin gene-related peptide and insulin-like growth factor 1 was increased at the early and middle stages of fracture healing in rats with brain injury and femoral fracture, which contributes to the proliferation and differentiation of various cells, as well as promoting osteogenesis. Calcitonin gene-related peptide and insulin-like growth factor 1 are the possible factors promoting fracture healing.

中国组织工程研究杂志出版内容重点：肾移植；肝移植；移植；心脏移植；组织移植；皮肤移植；皮瓣移植；血管移植；器官移植；组织工程

全文链接：

Key words: Brain injury, Femoral Fracture, Models, Animal, Calcitonin Gene-related Peptide, Insulin-like Growth Factor-1

CLC Number:

R318

Xiao Zeng-bing, Chen Tong, Fu Ai-jun, Zhu Jun, Li Jian-min, Li Su-hua, Sun Dong-liang, Yu Ling-ling, Wang Rui-gang, Song Xiang-qi . Establishment of rat models of brain injury combined with femoral closed fracture: expression of calcitonin gene-related peptide and insulin-like growth factor 1 in bone callus[J]. Chinese Journal of Tissue Engineering Research, 2015, 19(5): 657-661.

Figures/Tables 1

2.1 实验动物数量分析 48只手术SD大鼠共存活42只，其中颅脑损伤合并骨折组死亡4只，主要由于个体差异在颅脑损伤模型构建后颅脑损伤过重死亡；单纯骨折组由于局部感染及不明原因死亡2只。为保证实验准确性，根据随机抽样的原则补足各组模型动物。 2.2 苏木精-伊红染色结果造模后7 d：单纯骨折组镜下可见骨折端纤维母细胞自骨膜下增生长入骨折间隙，夹杂有少量的成骨细胞。颅脑损伤合并骨折组成骨细胞数目较单纯骨折组增多，骨折端有大量肉芽组织生长连接，纤维骨痂生成。造模后14 d：单纯骨折组镜下可见成骨细胞数目增多，骨折端肉芽组织生长，纤维性骨痂生成。骨折端可见骨膜下成骨，软骨内成骨现象，纤维性骨痂，核变得扁平。颅脑损伤合并骨折组骨折端有大量纤维性骨痂，软骨性骨痂和骨性骨痂，新生骨小梁长入，骨性骨痂较对照组明显增多，其中有丰富的血管再生。造模后28 d：单纯骨折组骨折端成骨细胞、纤维母细胞减少，纤维骨痂消失，代之以软骨骨痂与骨性骨痂。颅脑损伤合并骨折组骨折端为结构均一的编织骨痂，其中成骨细胞活跃，骨膜增厚明显。 2.3 骨痂中降钙素基因相关肽变化规律及免疫组化结果降钙素基因相关肽蛋白阳性表达的A值变化：造模后7 d颅脑损伤合并骨折组A值增高，造模后14 d维持高峰，逐渐开始下降，造模后28 d A值降至骨折组水平。单纯骨折组7 d出现阳性表达，2周达高峰，随后逐渐开始下降。统计分析表明，颅脑损伤合并骨折组在7，14 d与单纯骨折组比较差异有显著性意义(P < 0.05)。造模后28 d两组比较差异无显著性意义(P > 0.05)。颅脑损伤合并骨折组的组内比较差异有显著性意义(P <0.05)，单纯骨折组的组内比较差异无显著性意义(P > 0.05，表1)。 2.4 骨痂中胰岛素样生长因子1免疫组化结果单纯骨折组和颅脑损伤合并骨折组创伤后均表现为7 d骨折位点表达增强，14 d仍保持高水平表达，28 d骨折位点表达降低。统计学分析表明，颅脑损伤合并骨折组在7，14 d与单纯骨折组比较差异有显著性意义(P < 0.05)，28 d两组比较差异无显著性意义(P > 0.05)。颅脑损伤合并骨折组的组内比较差异有显著性意义 (P < 0.05)，单纯骨折组的组内比较差异无显著性意义(P > 0.05，表2)。"

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