摘要
目的探讨骨骼发育畸形的大鼠软骨组织内胰岛素样生长因子（insulin-like growth factors，IGFs）家族成员IGF-2的表达规律。方法应用环境类致畸因子二恶英中毒性最强的四氯二苯并二恶英，即2，3，7，8-四氯-二苯并-对-二恶英（2，3，7，8-tetrachlorodibenzo-p-dioxin，TCDD）构建先天性大鼠骨骼发育畸形动物模型。应用光镜和透射电镜观测骨骼畸形大鼠的足部软骨组织病理学改变。免疫组织化学染色分析大鼠软骨组织IGF-2蛋白的表达。应用TCDD干预体外培养的大鼠软骨细胞，采用RT-PCR及Western印迹杂交检测软骨细胞内的IGF-2mRNA及蛋白质的表达水平。结果TCDD（15μg／kg）诱导实验组33．3％的胎鼠出现单一或多种畸形，包括：内翻足、小脑畸形、腭裂、无尾畸形等，在骨骼畸形胎鼠的足部软骨发生带缩小，软骨细胞数量减少，软骨细胞核内粗面内质网扩张，核基质降解，线粒体嵴紊乱。15μg／kg剂量的TCDD使畸形胎鼠软骨细胞内IGF-2蛋白质的表达明显降低。TCDD（1×10^-8mol／L）作用体外培养的大鼠软骨细胞24h，细胞内IGF-2的基因转录和翻译水平分别减少80％和60％，P％0．05。结论IGF-2在大鼠软骨细胞内的低表达可能与TCDD对骨骼发育的致畸作用密切相关。
Objective To investigate the gene expression of insulin-like growth factors-2 （IGF- 2） in fetal rat with congenital skeleton malformation. Methods The fetal rat models with congenital skeleton malformation were induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin （TCDD） to the pregnant Wistar rats （day 10）. Histopathologic characteristics of cartilaginous tissue in fetal foot were detected with light microscope and transmission electron microscope. IGF-2 protein level in cartilaginous tissue was analyzed by immunocytochemical methods and image analysis. The IGF-2 mRNA and protein level in TCDD-treated chondrocytes in vitro were detected by reverse transcription polymerase chain reaction and western blotting analysis, respectively. Results TCDD（ 15 μg/kg）induced single or coalescent developmental skeleton defect in fetal rat （33. 3 %）, such as cross-foot, cleft spine, cleft palate, rumples and so on. The chondrogenesis center of tarsal bones and quantity of chondrocyte were decreased. There were expanding rough endoplasmic reticulum, degradation of nuclear matrix, and disorder of mitochondria cristae in cell nucleus of chondrocyte. IGF-2 protein level in TCDD-treated cartilaginous＇ tissue was decreased significantly. In chondrocyte treated with TCDD（ 1×10^-8 mol/L）in vitro, the expression of IGF-2 mRNA and protein were decreased 80% and 60%, respectively （P〈0. 05）. Conclusions The low expression of IGF-2 in chondrocyte may be related to the TCDD-induced developmental skeleton defect.
出处
《中华小儿外科杂志》
CSCD
北大核心
2008年第3期176-180,共5页
Chinese Journal of Pediatric Surgery
基金
国家自然科学基金资助项目（30500414）和辽宁省教育厅高等学校科学研究项目（05L508,20061010）资助
关键词
胰岛素样生长因子-Ⅱ
四氯二苯并二恶英
骨发育
肌肉骨骼畸形
Insulin-like growth factor-2
Tetrachlorodibenzodioxin
Bone development
Musculoskeletal abnormalities
