Wang Peihong, Hao Peng, Chen Xi, Li Linghan, Zhou Yongying, Zhang Xiaohan, Zhu Lin, Ying Ming, Han Ruifang, Wang Liming, Li Xuan
Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.
Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Tianjin, China.
Front Pharmacol. 2022 May 2;13:841267. doi: 10.3389/fphar.2022.841267. eCollection 2022.
Corneal neovascularization (CNV) is a sight-threatening condition usually associated with various inflammatory settings including chemical injury. High mobility group box 1 (HMGB1) is identified as an inflammatory alarmin in diverse tissue damage. Here, we evaluate the expression of HMGB1 and the consequences of its inhibition through its selective inhibitor glycyrrhizin (GLY) in alkali burn-induced corneal inflammation and neovascularization. GLY effectively attenuated alkali burn-induced HMGB1 expression at both mRNA and protein levels. Furthermore, slit-lamp analysis, ink perfusion, H&E staining, and CD31 histochemical staining showed that GLY relieved corneal neovascularization, while GLY attenuated VEGF expression via inhibiting HMGB1/NF-κB/HIF-1α signal pathway. In addition, GLY treatment decreased the cytokine expression of CCL2 and CXCL5, accompanied by the reduction of their receptors of CCR2 and CXCR2. GLY diminished the inflammatory cell infiltration of the cornea, as well as reduced the expression of IL-1β, IL-6, and TNF-α. Moreover, treatment with GLY reduced the degree of cornea opacity through inactivating extracellular HMGB1 function, which otherwise induces TGF-β1 release and myofibroblast differentiation. Furthermore, we found that GLY treatment attenuated the upregulation of miR-21 levels in alkali burned cornea; while inhibition of miR-21in keratocytes , significantly inhibited TGF-β1-induced myofibroblast differentiation. Collectively, our results suggested that targeting HMGB1-NFκb axis and miR-21 by GLY could introduce a therapeutic approach to counter CNV.
角膜新生血管化(CNV)是一种威胁视力的病症,通常与包括化学伤在内的各种炎症环境相关。高迁移率族蛋白B1(HMGB1)被确定为多种组织损伤中的一种炎症警报素。在此,我们评估HMGB1的表达及其通过其选择性抑制剂甘草甜素(GLY)抑制在碱烧伤诱导的角膜炎症和新生血管化中的后果。GLY在mRNA和蛋白质水平上均有效减弱碱烧伤诱导的HMGB1表达。此外,裂隙灯分析、墨水灌注、苏木精-伊红(H&E)染色和CD31组织化学染色显示,GLY减轻了角膜新生血管化,而GLY通过抑制HMGB1/NF-κB/HIF-1α信号通路减弱了血管内皮生长因子(VEGF)的表达。此外,GLY治疗降低了趋化因子CCL2和CXCL5的细胞因子表达,同时伴随着其受体CCR2和CXCR2的减少。GLY减少了角膜的炎性细胞浸润,并降低了白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)的表达。此外,GLY治疗通过使细胞外HMGB1功能失活降低了角膜混浊程度,否则细胞外HMGB1功能会诱导转化生长因子-β1(TGF-β1)释放和成肌纤维细胞分化。此外,我们发现GLY治疗减弱了碱烧伤角膜中miR-21水平的上调;而在角膜细胞中抑制miR-21可显著抑制TGF-β1诱导的成肌纤维细胞分化。总体而言,我们的结果表明,GLY靶向HMGB1-NFκb轴和miR-21可能为对抗CNV引入一种治疗方法。