Zhang Zhenzhen, Hu Xiaoli, Qi Xia, Di Guohu, Zhang Yangyang, Wang Qian, Zhou Qingjun
School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Sciences, Jinan, China.
State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong Academy of Medical Sciences, Qingdao, China.
Mol Vis. 2018 Apr 1;24:274-285. eCollection 2018.
To investigate the effect and mechanism of proresolving lipid mediator resolvin D1 (RvD1) on the corneal epithelium and the restoration of mechanical sensation in diabetic mice.
Type 1 diabetes was induced in mice with intraperitoneal streptozocin injections. The healthy and diabetic mice underwent removal of the central corneal epithelium, and then 100 ng/ml RvD1 or its formyl peptide receptor 2 (FPR2) antagonist WRW4 was used to treat the diabetic mice. Regeneration of the corneal epithelium and nerves was observed with sodium fluorescein staining and whole-mount anti-β3-tubulin fluorescence staining. The inflammatory response level was measured with hematoxylin and eosin staining (inflammatory cell infiltration), enzyme-linked immunosorbent assay (tumor necrosis factor alpha and interleukin-1 beta content), myeloperoxidase activity, and fluorescence staining (macrophage content). The reactive oxygen species (ROS) and glutathione (GSH) levels were examined with incubation with fluorescent probes, and oxidative stress-related protein expression levels were evaluated with fluorescence staining and western blotting.
Topical application of RvD1 promoted regeneration of the corneal epithelium in diabetic mice, accompanied by the reactivation of signaling and inflammation resolution related to regeneration of the epithelium. Furthermore, RvD1 directly attenuated the accumulation of ROS and nicotinamide adenine dinucleotide phosphate oxidase 2/4 expression, while RvD1 enhanced GSH synthesis and reactivated the Nrf2-ARE signaling pathway that was impaired in the corneal epithelium in the diabetic mice. More interestingly, topical application of RvD1 promoted regeneration of corneal nerves and completely restored impaired mechanical sensitivity of the cornea in diabetic mice. In addition, the promotion of corneal epithelial wound healing by RvD1 in diabetic mice was abolished by its FPR2 antagonist WRW4.
Topical application of RvD1 promotes corneal epithelial wound healing and the restoration of mechanical sensation in diabetic mice, which may be related to the lipid mediator's regulation of inflammation resolution, the reactivation of regenerative signaling in the epithelium, and the attenuation of oxidative stress.
研究促消退脂质介质消退素D1（RvD1）对糖尿病小鼠角膜上皮及机械感觉恢复的作用及机制。
通过腹腔注射链脲佐菌素诱导小鼠患1型糖尿病。对健康小鼠和糖尿病小鼠进行中央角膜上皮去除术，然后用100 ng/ml RvD1或其甲酰肽受体2（FPR2）拮抗剂WRW4治疗糖尿病小鼠。用荧光素钠染色和全层抗β3-微管蛋白荧光染色观察角膜上皮和神经的再生情况。用苏木精-伊红染色（炎症细胞浸润）、酶联免疫吸附测定（肿瘤坏死因子α和白细胞介素-1β含量）、髓过氧化物酶活性及荧光染色（巨噬细胞含量）检测炎症反应水平。用荧光探针孵育检测活性氧（ROS）和谷胱甘肽（GSH）水平，并用荧光染色和蛋白质免疫印迹法评估氧化应激相关蛋白表达水平。
局部应用RvD1可促进糖尿病小鼠角膜上皮再生，同时伴有与上皮再生相关的信号激活和炎症消退。此外，RvD1直接减弱了ROS的积累及烟酰胺腺嘌呤二核苷酸磷酸氧化酶2/4的表达，而RvD1增强了GSH合成并重新激活了糖尿病小鼠角膜上皮中受损的Nrf2-ARE信号通路。更有趣的是，局部应用RvD1可促进糖尿病小鼠角膜神经再生并完全恢复受损的角膜机械敏感性。此外，RvD1的FPR2拮抗剂WRW4消除了RvD1对糖尿病小鼠角膜上皮伤口愈合的促进作用。
局部应用RvD1可促进糖尿病小鼠角膜上皮伤口愈合及机械感觉恢复，这可能与该脂质介质对炎症消退的调节、上皮再生信号的重新激活以及氧化应激的减弱有关。
