Lu Bing-Wen, Liang Yu-Xiang, Liu Jin-Feng, Sun Zhong-Qing, So Kwok-Fai, Chiu Kin
Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China.
Adv Ophthalmol Pract Res. 2022 Dec 10;3(2):47-54. doi: 10.1016/j.aopr.2022.11.003. eCollection 2023 May-Jun.
Artesunate (ART), a member of the artemisinin family, possesses multi-properties, including anti-inflammation, anti-oxidation, and anti-tumor. ART was recently reported to show anti-neovascularization effect on the cornea, iris, and retina. Compared to the expensive anti-VEGF treatment, this versatile, economical treatment option is attractive in the ophthalmic field. The safety and toxicity profile of ART intravitreal application are in utmost need.
In this study, immortalized microglial (IMG) cells were treated with ART to determine the safe concentrations without inducing overt inflammatory reactions. Reverse transcription-polymerase chain reaction analysis was used to detect the cytokine expressions in IMG cells in response to ART stimulation. Various doses of ART were intravitreally injected into the right eyes of C57BL/6 mice. Retinal function was tested by electroretinogram, and retinal ganglion cell (RGC) survival was evaluated by counting Brn3a stained cells in flat-mounted retinas at 7 days after ART injection.
ART below 5μM was safe for IMG cells . Both 2.5 and 5 μM ART treatment increased IL-10 gene expression in IMG cells while not changing IL-1β, IL-6, TNF-α, and Arg-1. In the study, intravitreal injection of ART below 100 μM did not cause deterioration in the retinal function and RGC survival of the mouse eyes, while 1 mM ART treatment significantly attenuated both the scotopic and photopic b-wave amplitudes and impaired RGC survival. In addition, treatment with ART of 25, 50, and 100 μM significantly decreased TNF-α gene expression while ART of 100 μM significantly increased IL-10 in the mouse retina.
Intravitreal injection of 100 μM ART could downregulate TNF-α while upregulate IL-10 in the mouse retina without causing retinal functional deterioration and RGC loss. ART might be used as anti-inflammatory agent for retinal disorders.
青蒿琥酯（ART）是青蒿素家族的一员，具有多种特性，包括抗炎、抗氧化和抗肿瘤作用。最近有报道称，ART对角膜、虹膜和视网膜具有抗新生血管形成的作用。与昂贵的抗血管内皮生长因子（VEGF）治疗相比，这种多功能、经济的治疗选择在眼科领域具有吸引力。ART玻璃体内应用的安全性和毒性情况亟待明确。
在本研究中，用ART处理永生化小胶质细胞（IMG），以确定不引起明显炎症反应的安全浓度。采用逆转录-聚合酶链反应分析检测ART刺激后IMG细胞中的细胞因子表达。将不同剂量的ART玻璃体内注射到C57BL/6小鼠的右眼。通过视网膜电图检测视网膜功能，并在ART注射后7天通过计数平铺视网膜中Brn3a染色的细胞来评估视网膜神经节细胞（RGC）的存活情况。
5μM以下的ART对IMG细胞是安全的。2.5μM和5μM的ART处理均增加了IMG细胞中IL-10基因的表达，而未改变IL-1β、IL-6、TNF-α和Arg-1的表达。在该研究中，玻璃体内注射100μM以下的ART不会导致小鼠眼睛的视网膜功能和RGC存活情况恶化，而1mM的ART处理显著降低了暗视和明视b波振幅，并损害了RGC存活。此外，25μM、50μM和100μM的ART处理显著降低了小鼠视网膜中TNF-α基因的表达，而10０μM的ART显著增加了IL-10的表达。
玻璃体内注射100μM的ART可下调小鼠视网膜中的TNF-α，同时上调IL-10，且不会导致视网膜功能恶化和RGC丢失。ART可能用作治疗视网膜疾病的抗炎药物。
