目的探讨胰岛素样生长因子-2(Insulin—like growth factor2,IGF-2)在骨骼畸形大鼠肢端软骨细胞内的表达规律。方法应用光镜和透射电镜观测二噁英诱导的骨骼畸形大鼠足部软骨组织病理学改变。应用二噁英(1×10^-8mol/L)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-2 mRNA及蛋白质的表达水平。结果15μg/kg剂量的二噁英诱导实验组胎鼠出现多种畸形,内翻足、无尾畸形、腭裂等骨骼畸形发生率为33.3%。畸形胎鼠的肢端骨化中心发生带缩小,软骨细胞核内粗面内质网扩张,线粒体嵴紊乱。1×10^-8mol/L剂量的二噁英使体外培养的大鼠软骨细胞内IGF-2的mRNA及蛋白质的表达水平分别减少80%和60%(P〈0.05)。结论在二噁英诱导的骨骼畸形大鼠软骨细胞内IGF-2呈低表达状态。软骨细胞内IGF-2的表达可能与骨骼发育密切相关。
Objective To investigate the gene expression of insulin-like growth factors-2 (IGF-2) in fetal rat with congenital skeleton malformation. Methods Wistar fetal rat models with congenital skeleton malformation were constructed by treating with 15 μg/kg 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on pregnant day 10. Cartilaginous tissue in fetal foot was detected with light microscope and transmission electron microscope. Rat ehondrocyte were expered with 1 × 10^-8 mol/L TCDD in vitro. IGF-2 gene expression in ehondroeyte was detected by reverse transcription pelymerase chain reaction and western blotting. Results TCDD induced developmental skeleton defect in fetal rat (33.3 % ), such as cross-foot, cleft palate, rumpless and so on. The ehondrogenesis center of tarsal bones was diminished. There were expanding rough endoplasmie retieulum and disorder of mitoehondria eristae in nucleus of ehondrocyte. The expression of IGF-2 mRNA and protein were decreased 80% and 60%, respectively, in ehondrocyte treated with TCDD in vitro. Conclusion There was low expression of IGF-2 in ehondrocyte of fetal rat with congenital skeleton malformation. Expression of IGF-2 in ehondroeyte may be correlated with the developmental skeleton.