Zhang Shuya, Li Haiyan, Li Bo, Zhong Dingjuan, Gu Xuejiao, Tang Lingyun, Wang Yanyan, Wang Cun, Zhou Rong, Li Yan, He Yan, Chen Mozi, Huo Yuqing, Liu Xiao-Ling, Chen Jiang-Fan
Institute of Molecular Medicine, School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.
State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health, China and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou, Zhejiang, China.
Invest Ophthalmol Vis Sci. 2015 Dec;56(13):8108-19. doi: 10.1167/iovs.15-17202.
We critically evaluated the role of the adenosine A1 receptor (A1R) in normal development of retinal vasculature and pathogenesis of retinopathy of prematurity (ROP) by using the A1R knockout (KO) mice and oxygen-induced retinopathy (OIR) model.
Mice deficient in A1Rs and their wild-type (WT) littermates were examined during normal postnatal development or after being subjected to 75% oxygen from postnatal day (P) 7 to P12 and to room air from P12 to P17 (OIR model of ROP). Retinal vascularization was examined by whole-mount fluorescence and cross-sectional hematoxylin-eosin staining. Cellular proliferation, astrocyte and microglial activation, and tip cell function were determined by isolectin staining and immunohistochemistry. Apoptosis was determined by TUNEL assay.
Genetic deletion of the A1R did not affect normal retinal vascularization during postnatal development with indistinguishable three-layer vascularization patterns in retina between WT and A1R KO mice. In the OIR model, genetic deletion of the A1R resulted in stage-specific effects: reduced hyperoxia-induced retinal vaso-obliteration at P12, but reduced avascular area and attenuated hypoxia-induced intraretinal revascularization without affecting intravitreal neovascularization at P17 and reduced avascular areas in retina at P21. These distinct effects of A1Rs on OIR were associated with A1R control of apoptosis mainly in inner and outer nuclear layers at the vaso-obliterative phase (P12) and the growth of endothelium tip cells at the vasoproliferative phase (P17), without modification of cellular proliferation, astrocytic activation, and tissue inflammation.
Adenosine A1 receptor activity is not required for normal postnatal development of retinal vasculature but selectively controls hyperoxia-induced vaso-obliteration and hypoxia-driven revascularization by distinct cellular mechanisms.
我们通过使用A1受体基因敲除（KO）小鼠和氧诱导视网膜病变（OIR）模型，严格评估了腺苷A1受体（A1R）在视网膜血管正常发育及早产儿视网膜病变（ROP）发病机制中的作用。
在正常出生后发育期间或从出生后第（P）7天至P12天给予75%氧气并从P12天至P17天给予空气（ROP的OIR模型）后，检查缺乏A1R的小鼠及其野生型（WT）同窝小鼠。通过全视网膜荧光和横断面苏木精-伊红染色检查视网膜血管形成。通过异凝集素染色和免疫组织化学确定细胞增殖、星形胶质细胞和小胶质细胞活化以及顶端细胞功能。通过TUNEL测定法确定细胞凋亡。
A1R的基因缺失在出生后发育期间不影响正常视网膜血管形成，WT和A1R KO小鼠视网膜中的三层血管形成模式无明显差异。在OIR模型中，A1R的基因缺失产生阶段特异性效应：在P12时减少高氧诱导的视网膜血管闭塞，但在P17时减少无血管区并减弱缺氧诱导的视网膜内血管再生，且不影响玻璃体内新生血管形成，在P21时减少视网膜无血管区。A1R对OIR的这些不同效应与A1R对凋亡的控制有关，主要在血管闭塞期（P12）的内核层和外核层以及血管增殖期（P17）的内皮顶端细胞生长，而不改变细胞增殖、星形胶质细胞活化和组织炎症。
腺苷A1受体活性对于视网膜血管的正常出生后发育不是必需的，但通过不同的细胞机制选择性地控制高氧诱导的血管闭塞和缺氧驱动的血管再生。
