成纤维细胞因子4在大鼠拇指多指畸形体内表达变化的研究

Expression of fibroblast growth factor 4 in polydactyly of the thumb induced by cytarabine

目的通过对比研究成纤维细胞生长因子4（fibroblast growth factor-4，FGF-4）基因在阿糖胞苷所致的大鼠拇指多指畸形胚胎鼠的肢芽组织中的表达情况，初步阐明其在畸形鼠体内的表达规律，探索多指畸形的形成机制。方法选取2～3个月龄sD大鼠66只，于每13下午6时按雌雄2：1合笼，次13晨8时取出，查见阴道栓者定为孕期第0．5天。将怀孕大鼠随机分成两组：给药组和对照组。在怀孕第10．5天腹腔注射阿糖胞苷（100ms／ks）建立拇指多指畸形鼠的动物模型。选择不同怀孕时间的大鼠（10．5、11、11．5、12、12．5d），颈椎脱臼处死，低温无菌条件剪取肢芽组织迅速冰冻。采用肢芽组织提取mRNA，RT-PCR半定量分析方法检测不同胚龄肢芽组织FGF-4mRNA的表达变化。结果FGF-4mRNA的表达及其蛋白的表达在给药组胚胎鼠肢芽中比对照组增多，差异有统计学意义（P〈0．01）。结论阿糖胞苷可以导致大鼠胚胎鼠拇指多指畸形。FGF-4在阿糖胞苷所致的拇指多指畸形鼠的肢芽中呈现高表达。

Objective To observe the expression of fibroblast growth factor 4 （FGF-4） in polydactyly of the thumb induced by cytarabine and investigate the pathogenesis of polydactyly. Methods Sixty-six 2 to 3 months old Sprague Dawley rats were caged together daily from 6 pm to 8 am next morning by a male：female ratio of 1 ： 2. The day that a vaginal plug was found was considered as embryonic day 0.5 （E0.5）. 30 pregnant rats were assigned to the experimental group, wlfile another 30 were assigned as controls. At day El0. 5 intraperitoneal injection of cytarabine （ 100 mg/kg） was carried out in the experimental rats to induce polydactyly and syndactyly in the pups. Normal saline was injected to the control rats. El0.5 to El2.5 embryos were removed from the pregnant female rats and limb buds were taken out and fast frozen, mRNA was extracted from the limb buds. The expression of FGF-4 mRNA was quantified using RT-PCR. Results In the experimental group FGF-4 expression in the limb buds was significantly higher and lasted much longer than the control group （ P 〈0.01）. Conclusion The rat embryo＇s polydaetyly of the thumb can be induced by cytarabine. FGF-4 expression in the limb buds in the