Inhibition of endoplasmic reticulum stress by 4-phenylbutyrate alleviates retinal inflammation and the apoptosis of retinal ganglion cells after ocular alkali burn in mice
Inhibition of endoplasmic reticulum stress by 4-phenylbutyrate alleviates retinal inflammation and the apoptosis of retinal ganglion cells after ocular alkali burn in mice
复制标题
4-苯基丁酸抑制内质网应激减轻小鼠眼部碱烧伤后视网膜炎症和视网膜神经节细胞凋亡
DOI：
10.1007/s00011-022-01565-3
复制
发表时间：
2022-04-12
影响因子：
6.7
通讯作者：
Lin, Xiaofeng
中科院分区：
文献类型：
--
作者：
Huang, Yanqiao;Yuan, Miner;Lin, Xiaofeng
目的视网膜神经节细胞（RGC）凋亡是眼碱烧伤（OAB）后导致永久性视力损害的最严重并发症之一。目前，针对这种情况的治疗方案很少。本研究采用成熟的OAB小鼠模型，研究4-苯基丁酸（4-PBA）对OAB后内质网（ER）应激的影响。方法采用1 M NaOH诱导C57BL/6小鼠角膜碱烧伤。4-PBA （10 mg/kg， 250 μL /支）或生理盐水（250 μL /支）每天腹腔注射1次，连续3 d建立OAB模型。采用末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法（TUNEL）检测视网膜神经节细胞（RGCs）的凋亡情况，采用苏木精、伊红和免疫荧光法检测视网膜平片上视网膜神经节细胞的组织学损伤。采用实时荧光定量PCR、western blotting和组织学分析评估视网膜组织中关键炎症反应和内质网应激相关标志物的表达。结果4- pba可明显减轻RGC细胞凋亡，防止视网膜结构损伤。4-PBA抑制内质网应激可降低重要促炎细胞因子、肿瘤坏死因子α和白细胞介素-1 β的表达；抑制视网膜小胶质细胞和核因子κB （NF-κB）的活化。4-PBA降低了OAB小鼠视网膜组织和rgc中内质网应激分子、葡萄糖调节蛋白78、活化转录因子6、肌醇需要酶-1 （IRE1）、x- box结合蛋白1剪接和CCAAT/增强子结合蛋白同源蛋白的表达。结论4-PBA抑制内质网应激可通过IRE1/NF-κB信号通路减轻炎症反应，保护OAB小鼠视网膜和RGCs免受损伤。这些发现进一步表明，4-PBA可能对OAB治疗有潜在的治疗意义。
ObjectiveRetinal ganglion cell (RGC) apoptosis is one of the most severe complications that causes permanent visual impairment following ocular alkali burn (OAB). Currently, very few treatment options exist for this condition. This study was conducted to determine the effect of 4-phenylbutyric acid (4-PBA) on endoplasmic reticulum (ER) stress after OAB using a well-established OAB mouse model.MethodsOcular alkali burn was induced in C57BL/6 mouse corneas using 1 M NaOH. 4-PBA (10 mg/kg; 250 μL per injection) or saline (250 μL per injection) was injected intraperitoneally once per day for 3 days before the establishment of the OAB model. The apoptosis of retinal ganglion cells (RGCs) was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay, and the histological damage was examined by hematoxylin and eosin and immunofluorescence assay on retinal flat mounts. The key inflammatory response and the expression of ER stress-related markers in the retinal tissues were assessed by real-time PCR, western blotting and histologic analyses.Results4-PBA significantly alleviated the apoptosis of RGCs and prevented the structural damage of the retina, as determined by the evaluation of RGC density and retinal thickness. Inhibition of ER stress by 4-PBA decreased the expression of vital proinflammatory cytokines, tumor necrosis factor alpha, and interleukin-1 beta; and suppressed the activation of retinal microglial cells and nuclear factor-kappa B (NF-κB). 4-PBA reduced the expression of the ER stress molecules, glucose-regulated protein 78, activated transcription factor 6, inositol-requiring enzyme-1 (IRE1), X-box-binding protein 1 splicing, and CCAAT/enhancer-binding protein homologous protein, in the retinal tissues and RGCs of OAB mice.ConclusionsThe present study demonstrated that the inhibition of ER stress by 4-PBA alleviates the inflammatory response via the IRE1/NF-κB signaling pathway and protects the retina and RGCs from injury in an OAB mouse model. Such findings further suggest that 4-PBA might have potential therapeutic implications for OAB treatment.