视觉发育关键期单眼形觉剥夺弱视大鼠视皮层的差异表达基因及其功能分析

Differential expression genes and functional analysis in visual cortex of amblyopic rats with monocular form deprivation during the critical period of visual development

目的筛选视觉发育关键期单眼形觉剥夺弱视大鼠视皮层的差异表达基因,并分析其功能。方法选取出生13 d尚未睁眼SD大鼠24只,按随机数字表法均分为空白对照组、模型组。模型组进行右侧眼睑缝合建立单眼形觉剥夺弱视模型。出生60 d,麻醉处死大鼠,取其脑组织。用基因芯片实验筛选差异表达基因,用基因本体论(GO)和京都基因与基因组百科全书(KEGG)对差异表达基因进行富集分析。结果与空白对照组比较,模型组左侧视皮层差异表达基因共163个,右侧视皮层差异表达基因数共38个,共有差异表达基因16个。GO富集分析显示,左侧视皮层差异表达基因富集程度大于2的涉及22个条目,右侧视皮层差异表达基因富集程度大于2的涉及19个条目。KEGG富集分析显示,模型组差异表达基因主要功能集中于胚胎背腹轴线形成、光信号传导通路、丝裂原活化蛋白激酶(MAPK)信号通路、核苷酸结合寡聚化结构域(NOD)样受体信号通路、神经营养蛋白信号通路、神经递质配体-受体相互作用信号通路等。其中MAPK1、鸟氨酸结合蛋白Gα2(GNAT2)基因异常表达可能与视功能异常改变有关,MAPK1基因主要功能集中在胚胎背腹轴线形成、MAPK信号通路、NOD样受体信号通路、神经营养蛋白信号通路、神经配体-受体相互作用信号通路,GNAT2基因主要功能为光信号传导通路。结论视觉发育关键期进行单眼形觉剥夺可造成大鼠大脑视皮层基因异常表达,并引起其调控的信号通路相关基因表达改变,造成视觉信号传导功能异常;MAPK1、GNAT2基因异常表达可能是弱视发病的生物学机制之一。

Objective To screen the differentially expressed genes in the visual cortex of amblyopic rats with monocular form deprivation during the critical period of visual development and to analyze their biological functions.Methods Twenty-four 13-day-old SD rats with their eyes not yet open were randomly divided into the control group and model group,with 12 rats in each.In the model group,right eyelid suture was performed to establish monocular form deprivation amblyopia model.At 60 days after birth,the rats were anesthetized and sacrificed,and their brain tissues were collected.Gene chip technology was used to screen the differentially expressed genes.Gene ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)were used for enrichment analysis of the differentially expressed genes.Results Compared with the blank control group,163 differentially expressed genes in the left visual cortex of the model group,38 differentially expressed genes in the right visual cortex,and 16 differentially expressed genes in both sides.GO enrichment analysis showed that 22 GO entries were involved in the differentially expressed genes in the left visual cortex with a degree greater than 2,while 19 GO entries were involved in the differentially expressed genes in the right visual cortex.KEGG enrichment analysis showed that the main functions of differentially expressed genes in the model group were involved in the formation of embryonic dorsal ventral axis,light signaling pathway,MAPK signaling pathway,NOD-like receptor signaling pathway,neurotrophic protein signaling pathway,neural ligand-receptor interaction signaling pathway,and so on.The abnormal expression of MAPK1 and GNAT2 genes might be related to abnormal visual function.The main functions of MAPK1 gene were involved in the formation of embryonic dorsal ventral axis,MAPK signaling pathway,NOD-like receptor signaling pathway,neurotrophic protein signaling pathway,and neural ligand-receptor interaction signaling pathway,whereas GNAT2 was primarily associated with the phototransduction pathway.Conclusions Monocular form deprivation during the critical period of visual development can cause abnormal gene expression in the visual cortex of rats,further lead to changes in the expression of genes in the related signal pathways,leading to abnormal function of visual signal transduction.The abnormal expression of MAPK1 and GNAT2 genes may be two critical biological mechanisms underlying the pathogenesis of amblyopia.