目的:研究单眼形觉剥夺对被遮盖小鸡眼后极部巩膜转化生长因子-β1(TGF-b1)表达的影响以阐明小鸡形觉剥夺性近视眼(FDM)后极部巩膜细胞外基质(ECM)主动重塑的可能分子机制。
方法:随机选取15只1 d龄来亨雏鸡以半透明塑料眼罩单眼遮盖14 d制备FDM动物模型(FDM组),对侧眼为自身对照眼(SC组),同时随机选取15只同龄、非遮盖小鸡作为正常对照眼(NC组)。14 d后处死各组实验小鸡,取后极部巩膜,常规HE染色法进行组织病理学观察,逆转录聚合酶链反应(RT-PCR)一步法检测后极部巩膜TGF-β1mRNA表达及免疫组织化学法检测TGF-b1蛋白质表达。
结果:HE染色结果表明,与其余两组比较,FDM组小鸡眼后极部巩膜纤维层明显变薄与纤维化,软骨层相对增厚,双核细胞与不规则细胞明显增多,增生活跃;RT-PCR结果显示,FDM组后极部巩膜TGF-b1 mRNA表达明显下调,与NC、SC组比较差别有统计学意义(P<0.01);免疫组化结果显示,FDM组小鸡后极部巩膜TGF-b1阳性表达较NC、SC组明显减弱。
结论:形觉剥夺可明显下调后极部巩膜TGF-β1表达,其机制可能与基因转录调节有关。
【关键词】 形觉剥夺性近视眼,转化生长因子-β1,巩膜,小鸡
The Inhibitory Effects of Monocular Form-deprivation on Transforming Growth Factor beta 1 Gene expression in the Posterior Sclera of Deprived Chick Eye. Wentao-Yan, Wencan-Wu, Jia-Qu, Qinmei-Wang, Xiangtian-Zhou, Wensheng-Li. Wenzhou Ophthalmology and Optometry hospital of Medical College of Wenzhou, Wenzhou 325027, China.
Objective To investigate the inhibitory effects of form-deprivation on Transforming growth factor beta1 (TGF-β1) gene expression in the posterior sclera of monocularly deprived chick eyes to help disclose the molecular mechanism of active scleral remodeling of Extracellular Matrix(ECM) of high myopia.
Methods each eye of fifteen 1-day-old white leghorn chicks chosen randomly was covered for 14 days with plastic goggles to induce an animal model of form-deprivation myopia (FDM). The other non-deprived eye served as self-control group. Meanwhile, normal age-matched chicks were provided as negative control speciments. After 14 days refractive status and axial length of experimental eyes were determined with streak retinoscopy (without cycloplegia) and A-scan ultra-sonography under topical anaesthesia respectively. Killing the chicks, the posterior sclera of 5 chicks in each groups were collected for tranditional immune histochemistry and histo-pathologic studies to evaluate the expression of TGF-β1 and the pathologic changes in each groups respectively. The others were for TGF-β1 messenger RNA (mRNA) analyse. At first total RNA in each posterior sclera was extracted tranditionally using TRIZOL reagent and then expression levels of TGF-β1 mRNA were analyzed by one step reverse transcriptiontase-polymerase chain reaction (RT-PCR) using special primers for TGF-β1 gene.
Results Compared with normal and self-control groups, the fibril sclera in FDM group became more fibrosis and much thinner, and while the chondro sclera became thicker relatively. The expression levels of TGF-β1 mRNA in FDM group significantly increased (P<0.01) and no significantly difference existed between normal control groups and self-controlled ones (P>0.05). Immune histochemistry studies have shown that TGF-β1 protein expressed less in FDM group than in both control groups.
Conclusion Probably by influencing gene transforming levels monocular form-deprivation could lessen TGF-β1 gene expression in the posterior sclera of deprived chick eyes, which would be as an important step to trigger active scleral ECM remodeling process to develop high myopia.
[Key words] high myopia; Transforming growth factor beta1; sclera; chick.
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