鸡形觉剥夺性近视眼后极部巩膜胰岛素样生长因子-1/胰岛素样生长因子-2 mRNA表达的动态变化

目的观察鸡形觉剥夺性近视眼后极部巩膜胰岛素样生长因子(insulinlikegrowthfactor,IGF)IGF1/IGFmRNA表达水平的变化,探讨IGF1/IGF2在实验性近视眼发病中的作用。方法取孵化1d的白色来亨鸡36只,右眼为遮盖眼,左眼为自身对照眼。测量实验前以及单眼遮盖后第7天、第14天、第21天时实验眼和对照眼的屈光度和眼轴长度,并检测不同遮盖时间时鸡眼后极部巩膜IGF1/IGF2mRNA的表达水平。结果随着遮盖时间的延长,IGFmRNA在试验眼和对照眼后极部巩膜的表达水平均升高,但两者之间差异无显著性(P>0.05);实验眼后极部巩膜的IGF2mRNA表达水平在遮盖7d后即明显高于对照眼(P<0.001),随着遮盖时间的延长,实验眼后极部巩膜IGF2mRNA表达水平明显升高,而对照眼则逐渐下降,两者的差值明显增大。结论形觉剥夺可能通过上调鸡眼后极部巩膜IGF2mRNA表达水平,影响巩膜的发育和重塑,从而导致近视的形成。

Dynamic changes in IGF-1/IGF-2 mRNA expression in the posterior sclera of form deprivation myopia in the chicken

Objective To investigate the changes induced by form deprivation in IGF-1/IGF-2 mRNA expression in the posterior sclera of chickens and assess the role of IGF-1/IGF-2 in the pathogenesis of myopia.Methods Thirty-six one-day-old white Lehen chickens were subjected to form deprivation (FD) with a monocular occluder. The right eyes were form-deprived and the contralateral, untreated eyes of the animals served as interocular controls. Refraction and axial eye length of all animals were measured at the beginning and 7, 14 and 21 days after the start of treatment. RT-PCR was used to detect the levels of IGF-1/IGF-2 mRNA at the specified time periods.Results The level of IGF-1 mRNA in the posterior sclera increased in FD and control eyes during the treatment period, but no significant difference was observed between those two groups (P>0.05). The level of IGF-2 mRNA in FD eyes was higher after seven days of deprivation compared to interocular controls (P<0.001). Expression of IGF-2 mRNA increased in FD eyes but decreased in control eyes during FD, and the difference was more significant at 21 days than at 7 days.Conclusion Form deprivation might affect the development and remodeling of the sclera and induce myopia by upregulating the level of IGF-2 mRNA expression in the posterior sclera of the chicken.