Wang Ya'nuo, Gao Shuang, Gao Sha, Li Na, Xie Bing, Shen Xi
Department of Ophthalmology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Er Road, Shanghai, 200025, China.
Department of Ophthalmology, Ruijin Hospital, Lu Wan Branch, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
Cell Biosci. 2021 May 1;11(1):82. doi: 10.1186/s13578-021-00593-6.
Neovascularization is a leading cause of visual loss typically associated with diabetic retinopathy (DR) and retinopathy of prematurity (ROP). Interleukin-17A (IL-17A) and endoplasmic reticulum (ER) stress both have been demonstrated to play a proangiogenic role in ischemic retinopathies. However, the relationship between IL-17A and ER stress in retinal neovascularization (RNV) under hypoxic conditions and its underlying mechanisms remain unclear.
In this study, oxygen-induced retinopathy (OIR) mice model was established and intravitreal injections were conducted. Changes of IL-17A and ER stress markers in retinas and cultured primary bone marrow derived macrophage (BMDM) under normoxic or hypoxic conditions were detected. Western blotting, Real-Time RT-PCR, Immunofluorescence assays were conducted to explore the roles and relationship of IL-17A and ER stress in RNV, as well as its underlying mechanisms.
Compared to that in normal controls, IL-17A and ER stress markers were all remarkably increased under hypoxic conditions both in vivo and in vitro. Neutralization or knock out of IL-17A decreased ER stress. ER stress inhibitor 4-phenylbutyrate (4-PBA), attenuated the production of IL-17A, suggesting a positive feedback loop between IL-17A and ER stress. Inhibition of IL-17A or ER stress decreased areas of nonperfusion and neovascularization in OIR retinas. As TXNIP/NLRP3 pathway activation has been demonstrated to be involved in increased retinal vascular permeability of ischemic retinopathy, we observed that TXNIP/NLRP3 pathway mediated in the interaction between IL-17A and ER stress under hypoxic conditions.
The interplay between IL-17A and ER stress contributes to RNV in macrophages via modulation of TXNIP/NLRP3 signaling pathway under hypoxic conditions. The feedback loops may become an innovative and multiple pharmacological therapeutic target for ischemic retinopathy.
新生血管形成是导致视力丧失的主要原因，通常与糖尿病视网膜病变（DR）和早产儿视网膜病变（ROP）相关。白细胞介素-17A（IL-17A）和内质网（ER）应激均已被证明在缺血性视网膜病变中发挥促血管生成作用。然而，低氧条件下IL-17A与ER应激在视网膜新生血管形成（RNV）中的关系及其潜在机制仍不清楚。
在本研究中，建立了氧诱导视网膜病变（OIR）小鼠模型并进行玻璃体内注射。检测常氧或低氧条件下视网膜及培养的原代骨髓来源巨噬细胞（BMDM）中IL-17A和ER应激标志物的变化。进行蛋白质免疫印迹法、实时逆转录聚合酶链反应、免疫荧光分析，以探讨IL-17A和ER应激在RNV中的作用及关系，以及其潜在机制。
与正常对照组相比，体内和体外低氧条件下IL-17A和ER应激标志物均显著增加。中和或敲除IL-17A可降低ER应激。ER应激抑制剂4-苯基丁酸（4-PBA）可减弱IL-17A的产生，提示IL-17A与ER应激之间存在正反馈回路。抑制IL-17A或ER应激可减少OIR视网膜的无灌注区和新生血管形成面积。由于硫氧还蛋白相互作用蛋白（TXNIP）/NLRP3炎性小体途径的激活已被证明与缺血性视网膜病变中视网膜血管通透性增加有关，我们观察到TXNIP/NLRP3途径介导了低氧条件下IL-17A与ER应激之间的相互作用。
在低氧条件下，IL-17A与ER应激之间的相互作用通过调节TXNIP/NLRP3信号通路促进巨噬细胞中的RNV。这些反馈回路可能成为缺血性视网膜病变创新的多靶点药物治疗靶点。
