Involvement of Nox2 NADPH Oxidase in Retinal Neovascularization
Involvement of Nox2 NADPH Oxidase in Retinal Neovascularization
复制标题
Nox2 NADPH氧化酶参与视网膜新生血管形成
DOI：
10.1167/iovs.13-12883
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发表时间：
2013-10-01
影响因子：
4.4
通讯作者：
Dusting, Gregory J.
中科院分区：
文献类型：
--
作者：
Chan, Elsa C.;van Wijngaarden, Peter;Dusting, Gregory J.
目的.视网膜中新血管的增殖是视力受损的主要原因。烟酰胺腺嘌呤二核苷酸磷酸（NADPH）氧化酶（Nox）参与缺血诱导的血管生成的细胞信号转导，但其在视网膜新生血管形成中的作用尚不清楚。我们分析了氧诱导的视网膜病变（OIR）中视网膜新生血管对Nox 2亚型的依赖性。将7日龄（P7）的新生C57 BL/6小鼠置于高氧室（75%O-2）中5天，然后暴露于室内空气中5天。分别在P8和P17采集眼睛用于定量视网膜血管闭塞和新生血管形成。RT-PCR法检测视网膜Nox 2和VEGF-A的表达，二氢乙锭（DHE）原位染色法检测视网膜超氧化物的生成。在野生型（WT）小鼠中，OIR的特征在于P8时的中央视网膜血管闭塞和P17时的新生血管形成，这与Nox 2和VEGF-A基因表达的增加、超氧化物的产生和Iba-1阳性细胞在内层视网膜中的积累有关。相比之下，Nox 2基因敲除小鼠在P17时表现出明显较少的视网膜新生血管和VEGF-A mRNA表达，尽管在P8时显示出相当的血管闭塞。这些变化伴随着DHE荧光的减少和Iba-1阳性细胞在缺氧视网膜中的积聚。在OIR小鼠模型中，Nox 2产生的活性氧簇（ROS）促进VEGF-A的视网膜表达和新生血管形成。靶向Nox 2的治疗可能对减少早产儿视网膜病变、糖尿病和其他由VEGF驱动的疾病过程中的异常视网膜新生血管形成具有价值。
PURPOSE. The proliferation of new blood vessels in the retina is a leading cause of vision impairment. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox) is involved in cell signaling for ischemia-induced angiogenesis, but its role in retinal neovascularization is unclear. We have analyzed the dependence of retinal neovascularization on the Nox2 isoform in oxygen-induced retinopathy (OIR) in mice.METHODS. Neonatal C57BL/6 mice aged 7 days (P7) were placed in a hyperoxic chamber (75% O-2) for 5 days, followed by 5 days of exposure to room air. Eyes were harvested on P8 and P17 for the quantification of retinal vaso-obliteration and neovascularization, respectively. The retinal expression of Nox2 and VEGF-A were measured by RT-PCR, while superoxide generation was detected by in situ dihydroethidium (DHE) staining of fresh frozen sections.RESULTS. In wild type (WT) mice, OIR was characterized by central retinal vaso-obliteration at P8 and neovascularization at P17, which was associated with increases in Nox2 and VEGF-A gene expression, superoxide generation, and accumulation of Iba-1 positive cells in the inner retina. In contrast, Nox2 knockout mice exhibited markedly less retinal neovascularization and VEGF-A mRNA expression at P17, despite showing comparable vaso-obliteration at P8. These changes were accompanied by reductions in DHE fluorescence and Iba-1-positive cell accumulation in the hypoxic retina.CONCLUSIONS. The Nox2-generated reactive oxygen species (ROS) facilitate the retinal expression of VEGF-A and neovascularization in this mouse model of OIR. Therapies targeting Nox2 could be of value to reduce aberrant retinal neovascularization in retinopathy of prematurity, diabetes, and other disease processes driven by VEGF.