Zhang Yumeng, Huang Hanwen, Zhong Huimin, Zhang Yang, He Siqi, Guo Yanzhi, Wang Yiwei, Huang Ping, Huang Shouyue, Zhong Yisheng
Department of Ophthalmology, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China.
Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Invest Ophthalmol Vis Sci. 2025 Jun 2;66(6):8. doi: 10.1167/iovs.66.6.8.
In patients with glaucoma, progressive degeneration of retinal ganglion cells (RGCs) leads to irreversible visual impairments. Despite recent studies indicating that senescence is associated with RGC death, the underlying molecular mechanisms remain unclear.
The chronic ocular hypertension (COH) mouse model was established by infusing a crosslinking hydrogel into the anterior chamber. Cellular senescence was evaluated using Western blot analysis, cell cycle, senescence-associated β-galactosidase (SA-β-gal) staining, enzyme-linked immunosorbent assay, and immunofluorescence. Functional experiments were conducted in retinal precursor (R28) cells through small interfering RNA-mediated knockdown and plasmid-mediated overexpression. Additionally, the role of the protein arginine methyltransferase 5 (PRMT5)-regulated Wnt/β-catenin pathway in RGC senescence was investigated via intravitreal injection of GSK3326595 and CHIR99021 in mice.
We demonstrate that PRMT5 is markedly downregulated in RGC in a COH mouse model, correlating with increased RGC senescence induced by elevated intraocular pressure. Silencing PRMT5 significantly accelerated senescence, as evidenced by increased SA-β-gal activity, cell cycle arrest, and senescence marker upregulation. Cotreatment with GSK3β inhibitor CHIR99021 alleviated hypoxia-induced senescence and reactivated the Wnt/β-catenin pathway, while the antagonist FH535 negated the neuroprotective effects of PRMT5 overexpression. In vivo, the PRMT5 inhibitor GSK3326595 reduced RGC survival and heightened senescence markers, whereas CHIR99021 mitigated RGC loss and restored Wnt/β-catenin signaling.
Taken together, these findings highlight the critical role of the PRMT5-regulated Wnt/β-catenin pathway in RGC senescence and neurodegeneration. Targeting this pathway represents a promising therapeutic strategy for glaucoma.
在青光眼患者中，视网膜神经节细胞（RGCs）的进行性退化会导致不可逆的视力损害。尽管最近的研究表明衰老与RGC死亡有关，但其潜在的分子机制仍不清楚。
通过向前房注入交联水凝胶建立慢性高眼压（COH）小鼠模型。使用蛋白质印迹分析、细胞周期、衰老相关β-半乳糖苷酶（SA-β-gal）染色、酶联免疫吸附测定和免疫荧光评估细胞衰老。通过小干扰RNA介导的敲低和质粒介导的过表达在视网膜前体细胞（R28）中进行功能实验。此外，通过向小鼠玻璃体内注射GSK3326595和CHIR99021，研究蛋白质精氨酸甲基转移酶5（PRMT5）调节的Wnt/β-连环蛋白通路在RGC衰老中的作用。
我们证明在COH小鼠模型中，PRMT5在RGC中显著下调，这与眼压升高诱导的RGC衰老增加相关。沉默PRMT5显著加速衰老，SA-β-gal活性增加、细胞周期停滞和衰老标志物上调证明了这一点。与GSK3β抑制剂CHIR99021共同处理可减轻缺氧诱导的衰老并重新激活Wnt/β-连环蛋白通路，而拮抗剂FH535则消除了PRMT5过表达的神经保护作用。在体内，PRMT5抑制剂GSK3326595降低了RGC存活率并提高了衰老标志物水平，而CHIR99021减轻了RGC损失并恢复了Wnt/β-连环蛋白信号传导。
综上所述，这些发现突出了PRMT5调节的Wnt/β-连环蛋白通路在RGC衰老和神经退行性变中的关键作用。靶向该通路代表了一种有前景的青光眼治疗策略。
