Guan Chaoqiang, Zhang Linglin, Fomo Kristian Nzogang, Yang Jie, Pfeiffer Norbert, Grus Franz H
Department of Ophthalmology, University Medical Center of the Johannes Gutenberg-University, Langenbeckstr. 1, 55131, Mainz, Germany.
J Neuroinflammation. 2025 Jun 17;22(1):159. doi: 10.1186/s12974-025-03482-8.
Glaucoma is a progressive neurodegenerative disorder that leads to irreversible vision loss, with neuroinflammation recognized as a key factor. Overexpression of glial fibrillary acidic protein (GFAP) is linked to glaucoma pathogenesis and plays a pivotal role in astrocyte-driven neuroinflammation. This study aimed to assess the neuroprotective effects of a monoclonal antibody (mAb) targeting GFAP in glaucoma and to elucidate the underlying mechanisms.
An ocular hypertension (OHT) glaucoma model was established in female Sprague Dawley rats using episcleral vein occlusion. Three doses of GFAP mAb (2.5, 25, 50 µg) or vehicle were administered via intravitreal injection. Retinal nerve fiber layer (RNFL) thickness and photopic electroretinogram were monitored longitudinally. Retinal ganglion cell (RGC) survival and glial responses were evaluated with immunostaining. Western blot and microarray analyses were performed to investigate molecular and pathway alterations. Additionally, a cobalt chloride (CoCl)-induced degenerative R28 cell model was used to validate the protective effects of GFAP mAb in vitro. A bioinformatics re-analysis of a public glaucomatous retina protein dataset was conducted using GSEA, GO, and Cytoscape with GENEMANIA.
OHT resulted in a significant loss of RNFL thickness, PhNR amplitude, and RGC survival, all of which were preserved by GFAP mAb treatment. Retinal astrocyte reactivity was inhibited by GFAPmAb in a dose-dependent manner by suppressing GFAP protein overexpression. Notably, 25 µg GFAP mAb effectively regulated both astrocyte and microglial reactivity, leading to a substantial attenuation of neuroinflammation. Mechanistically, GFAP mAb inhibited the p38 MAPK and NF-κB pathways and the NLRP3/Caspase-1/GSDMD axis. In vitro, GFAP mAb improved R28 cell viability under CoCl exposure while reducing cell death via inhibition of pyroptosis. Bioinformatic re-analysis highlighted gliosis as a prominent pathway in the glaucomatous retina and indicated GFAP and Caspase1 as central nodes in the putative mechanism network modulated by GFAP mAb.
This study demonstrates that GFAP mAb inhibits astrogliosis and glial-glial activation, exerting neuroprotection through the inhibition of inflammation and pyroptosis. The findings suggest that targeting GFAP represents a promising immunotherapeutic strategy for glaucoma treatment.
青光眼是一种进行性神经退行性疾病，可导致不可逆的视力丧失，神经炎症被认为是一个关键因素。胶质纤维酸性蛋白（GFAP）的过度表达与青光眼的发病机制有关，并在星形胶质细胞驱动的神经炎症中起关键作用。本研究旨在评估靶向GFAP的单克隆抗体（mAb）在青光眼中的神经保护作用，并阐明其潜在机制。
采用巩膜静脉阻塞法在雌性Sprague Dawley大鼠中建立高眼压（OHT）青光眼模型。通过玻璃体内注射给予三种剂量的GFAP mAb（2.5、25、50μg）或赋形剂。纵向监测视网膜神经纤维层（RNFL）厚度和明视视网膜电图。通过免疫染色评估视网膜神经节细胞（RGC）存活和胶质细胞反应。进行蛋白质印迹和微阵列分析以研究分子和信号通路改变。此外，使用氯化钴（CoCl）诱导的退行性R28细胞模型在体外验证GFAP mAb的保护作用。使用GSEA、GO和带有GENEMANIA的Cytoscape对公开的青光眼视网膜蛋白质数据集进行生物信息学重新分析。
OHT导致RNFL厚度、PhNR振幅和RGC存活显著丧失，而GFAP mAb治疗可保留所有这些指标。GFAP mAb通过抑制GFAP蛋白过度表达以剂量依赖性方式抑制视网膜星形胶质细胞反应性。值得注意的是，25μg GFAP mAb有效调节星形胶质细胞和小胶质细胞反应性，导致神经炎症显著减轻。机制上，GFAP mAb抑制p38 MAPK和NF-κB信号通路以及NLRP3/Caspase-1/GSDMD轴。在体外，GFAP mAb在CoCl暴露下提高R28细胞活力，同时通过抑制细胞焦亡减少细胞死亡。生物信息学重新分析突出了胶质增生是青光眼视网膜中的一个突出信号通路，并表明GFAP和Caspase1是GFAP mAb调节的假定机制网络中的中心节点。
本研究表明，GFAP mAb抑制星形胶质细胞增生和胶质细胞-胶质细胞激活，通过抑制炎症和细胞焦亡发挥神经保护作用。这些发现表明，靶向GFAP是一种有前景的青光眼免疫治疗策略。
