Li Fei, Zhang Qiuxiang, Rong Yan, Xiang Sifei, Wang Junming
Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Exp Eye Res. 2025 Feb;251:110244. doi: 10.1016/j.exer.2025.110244. Epub 2025 Jan 18.
The abrupt and substantial elevation of intraocular pressure (IOP) in acute glaucoma induces retinal ischemia/reperfusion (I/R) injury, resulting in progressive retinal ganglion cell (RGC) death and irreversible visual impairment. PANoptosis, a form of regulated cell death consisting of pyroptosis, apoptosis and necroptosis, is reported to be involved in high IOP-induced RGC death. However, the precise mechanisms of RGC death remain unclear, and neuroinflammation is considered to play a vital role. TAT-N24, a synthetic inhibitor targeting the p55 regulatory subunit of phosphatidylinositol 3-kinase (p55PIK) signaling, demonstrates anti-inflammatory effect in uveitis and may have certain neuroprotective effects. Therefore, we investigated whether TAT-N24 could shield RGCs from immunoinflammatory damage in an acute glaucoma mouse model and explored the potential mechanism associated with PANoptosis. A mouse model of acute ocular hypertension (AOH) was established. Intravitreal injection of TAT-N24 was conducted to evaluate its impact on RGC death. The expression levels of key components in PANoptosis were analyzed using RT-qPCR and Western blotting. Immunohistochemistry and immunofluorescence staining on eyeball sections were employed to assess the expression of p55PIK, Brn3a, and ionized calcium binding adaptor molecule 1 (Iba1). Retinal structure was examined by H&E staining, while cell apoptosis was evaluated by TdT-mediated dUTP nick end labeling (TUNEL). The results showed that intravitreal injection of TAT-N24 effectively alleviated RGC death and retinal damage induced by AOH injury. The key components in PANoptosis were markedly upregulated after AOH injury, while these components were significantly inhibited after TAT-N24 treatment. Moreover, the expression levels of Z-DNA-binding protein 1 (ZBP1)-PANoptosome (ZBP1, RIPK1, RIPK3, and Caspase-8), NLR family pyrin domain-containing protein 3 (NLRP3), and NLR family CARD domain-containing protein 4 (NLRC4) inflammasomes were notably elevated after AOH injury, which was significantly suppressed by TAT-N24. In conclusion, PANoptosis was involved in AOH-induced RGC death and retinal damage. TAT-N24 exhibited an anti-PANoptotic effect, protecting RGCs by inhibiting ZBP1-PANoptosome as well as NLRP3 and NLRC4 inflammasomes after AOH injury.
急性青光眼时眼内压（IOP）的突然大幅升高会引发视网膜缺血/再灌注（I/R）损伤，导致视网膜神经节细胞（RGC）进行性死亡和不可逆的视力损害。据报道，PAN细胞焦亡，一种由细胞焦亡、凋亡和坏死性凋亡组成的程序性细胞死亡形式，参与了高眼压诱导的RGC死亡。然而，RGC死亡的确切机制仍不清楚，神经炎症被认为起着至关重要的作用。TAT-N24是一种靶向磷脂酰肌醇3激酶（p55PIK）信号传导的p55调节亚基的合成抑制剂，在葡萄膜炎中显示出抗炎作用，可能具有一定的神经保护作用。因此，我们研究了TAT-N24是否能在急性青光眼小鼠模型中保护RGC免受免疫炎症损伤，并探索了与PAN细胞焦亡相关的潜在机制。建立了急性高眼压（AOH）小鼠模型。进行玻璃体内注射TAT-N24以评估其对RGC死亡的影响。使用RT-qPCR和蛋白质免疫印迹法分析PAN细胞焦亡关键成分的表达水平。采用眼球切片的免疫组织化学和免疫荧光染色来评估p55PIK、Brn3a和离子钙结合衔接分子1（Iba1）的表达。通过苏木精-伊红（H&E）染色检查视网膜结构，同时通过末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法（TUNEL）评估细胞凋亡。结果表明，玻璃体内注射TAT-N24有效减轻了AOH损伤诱导的RGC死亡和视网膜损伤。AOH损伤后，PAN细胞焦亡的关键成分显著上调，而在TAT-N24处理后这些成分受到显著抑制。此外，AOH损伤后Z-DNA结合蛋白1（ZBP1）-PAN细胞焦亡小体（ZBP1、RIPK1、RIPK3和半胱天冬酶-8）、NLR家族含pyrin结构域蛋白3（NLRP3）和NLR家族含CARD结构域蛋白4（NLRC4）炎性小体的表达水平显著升高，而TAT-N24显著抑制了这些升高。总之，PAN细胞焦亡参与了AOH诱导的RGC死亡和视网膜损伤。TAT-N24表现出抗PAN细胞焦亡作用，通过抑制AOH损伤后的ZBP1-PAN细胞焦亡小体以及NLRP3和NLRC4炎性小体来保护RGC。
