氧诱导新生小鼠视网膜病变中血管新生和氧应激相关基因表达的变化

Altered expression of genes related with angiogenesis and oxidative stress during the development of oxygen-induced retinopathy in newborn mice

目的建立氧诱导新生小鼠视网膜病变(oxygen-induced retinopathy,OIR)模型,观察视网膜血管新生情况,检测OIR病变过程中调控血管新生和氧应激相关基因表达的变化。方法新生小鼠出生后d 7,置75.5%高氧环境中饲养5 d,再返回正常氧环境继续饲养5 d,建立OIR模型。运用视网膜免疫荧光染色检测OIR小鼠视网膜中血管新生情况;运用Real-time PCR技术检测基因表达情况。结果视网膜免疫荧光染色结果显示,OIR小鼠视网膜在高氧诱导视网膜微血管消退的基础上,相对缺氧状态诱导出现明显的新生血管。Real-time PCR结果显示OIR模型小鼠视网膜中:血管内皮细胞生长因子(vascular endothelial growth factor,VEGF)及其受体(VEGFR)家族中:VEGFA、VEGFD、VEGFR1、VEGFR2的基因表达分别上调1.73、1.71、1.48、1.80倍;血小板衍生生长因子(platelet-derived growth factor,PDGF)及其受体(PDGFR)家族中:PDGFA、PDGFB、PDGFRa、PDGFRb的基因表达分别上调1.29、1.71、1.42、1.42倍;基质金属蛋白酶(matrix metalloproteinases,MMPs)中的MMP2基因表达上调1.48倍;参与调控氧化应激的核转录因子Nrf2[nuclear factor(erythroid-derived 2)-like 2]及受其调控的下游基因包括谷氨酸-半胱氨酸连接酶(glutamatecysteine ligase,GCL)的催化(GCLC)和调节(GCLM)亚单位的基因表达均下调,表达量分别为正常的0.28、0.76、0.49。结论 OIR小鼠视网膜病变过程中,视网膜中促进血管新生相关基因表达上调,而抗氧化相关基因表达下调。

Aim To observe the retinal angiogenesis and detect the altered expression of genes related with angiogenesis and oxidative stress during the develop-ment of oxygen-induced retinopathy （ OIR） in newborn mice. Methods OIR was established in newborn mice according to the protocol of Smith et al. Newborn mice at 7 days old were placed into 75 . 5% oxygen for up to 5 days, and then they were put in room air for another 5 days. Retinal neovascularization was ob-served by immunofluorescence staining with cluster of differentiation 31 （ CD31 ） . Gene expression was de-tected using Real-time PCR analysis. Retinal CD31 immunofluorescence staining assay showed that relative hypoxia induced retinal neovascularization in OIR mice after hyperoxia-induced subside of retinal microvascu-lar. Results Real-time PCR analysis showed that vas-cular endothelial growth factor （ VEGF） and its recep-tor （ VEGFR） such as VEGFA, VEGFD, VEGFR1, VEGFR2 gene expression were increased in OIR mouseas compared to control. Platelet-derived growth factor （ PDGF） and its receptor （ PDGFR） such as PDGFA, PDGFB, PDGFRa, PDGFRb gene expression was also increased in OIR mouse as compared to control. Matrix metalloproteinases （ MMPs ） such as MMP2 gene ex-pression were increased in OIR mouse as compared to control. Gene expressions of nuclear factor-related fac-tor （ Nrf2 ） and its downstream genes such as the two subunits of glutamate-cysteine ligase （ GCL）：the cata-lytic subunit （ GCLC） and regulatory subunit （ GCLM） were both decreased in OIR mouse as compared to con-trol. Conclusion Our research demonstrates that the expression of genes related with angiogenesis is in-creased in retinas in the development of OIR in mice, whereas the expression of Nrf2 and its downstream genes is all decreased.