Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA 70112, USA.
Department of Ophthalmology, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA 70112, USA.
Biomolecules. 2023 May 13;13(5):831. doi: 10.3390/biom13050831.
To investigate the anti-inflammatory and anti-angiogenic effects of the bioactive lipid mediator LXA4 on a rat model of severe corneal alkali injury.
To induce a corneal alkali injury in the right eyes of anesthetized Sprague Dawley rats. They were injured with a Φ 4 mm filter paper disc soaked in 1 N NaOH placed on the center of the cornea. After injury, the rats were treated topically with LXA4 (65 ng/20 μL) or vehicle three times a day for 14 days. Corneal opacity, neovascularization (NV), and hyphema were recorded and evaluated in a blind manner. Pro-inflammatory cytokine expression and genes involved in cornel repair were assayed by RNA sequencing and capillary Western blot. Cornea cell infiltration and monocytes isolated from the blood were analyzed by immunofluorescence and by flow cytometry.
Topical treatment with LXA4 for two weeks significantly reduced corneal opacity, NV, and hyphema compared to the vehicle treatment. RNA-seq and Western blot results showed that LXA4 decreased the gene and protein expression of pro-inflammatory cytokines interleukin (IL)-1β and IL-6 and pro-angiogenic mediators matrix metalloproteinase (MMP)-9 and vascular endothelial growth factor (VEGFA). It also induces genes involved in keratinization and ErbB signaling and downregulates immune pathways to stimulate wound healing. Flow cytometry and immunohistochemistry showed significantly less infiltration of neutrophils in the corneas treated with LXA4 compared to vehicle treatment. It also revealed that LXA4 treatment increases the proportion of type 2 macrophages (M2) compared to M1 in blood-isolated monocytes.
LXA4 decreases corneal inflammation and NV induced by a strong alkali burn. Its mechanism of action includes inhibition of inflammatory leukocyte infiltration, reduction in cytokine release, suppression of angiogenic factors, and promotion of corneal repair gene expression and macrophage polarization in blood from alkali burn corneas. LXA4 has potential as a therapeutic candidate for severe corneal chemical injuries.
研究生物活性脂质介质 LXA4 对大鼠严重角膜碱烧伤模型的抗炎和抗血管生成作用。
将麻醉的 Sprague Dawley 大鼠右眼用直径 4mm 的滤纸浸以 1N NaOH 溶液后置于角膜中央造成碱烧伤。损伤后，大鼠每日用 LXA4（65ng/20μL）或载体进行 3 次眼部局部治疗，共 14 天。盲法记录和评估角膜混浊、新生血管形成（NV）和前房积血。通过 RNA 测序和毛细血管 Western blot 检测促炎细胞因子表达和角膜修复相关基因。通过免疫荧光和流式细胞术分析角膜细胞浸润和从血液中分离的单核细胞。
与载体治疗相比，LXA4 局部治疗两周可显著降低角膜混浊、NV 和前房积血。RNA-seq 和 Western blot 结果显示，LXA4 降低了促炎细胞因子白细胞介素（IL）-1β和 IL-6 以及促血管生成介质基质金属蛋白酶（MMP）-9 和血管内皮生长因子（VEGFA）的基因和蛋白表达。它还诱导角化和 ErbB 信号相关基因的表达，并下调免疫途径以刺激伤口愈合。流式细胞术和免疫组织化学显示，与载体治疗相比，LXA4 处理的角膜中中性粒细胞浸润明显减少。它还表明，LXA4 治疗增加了血液分离的单核细胞中 2 型巨噬细胞（M2）与 1 型巨噬细胞（M1）的比例。
LXA4 可减少由强碱烧伤引起的角膜炎症和 NV。其作用机制包括抑制炎症性白细胞浸润、减少细胞因子释放、抑制血管生成因子以及促进角膜修复基因表达和血液中巨噬细胞极化。LXA4 可能成为严重角膜化学损伤的治疗候选药物。
