Fang Wangyi, Huang Xiaojing, Wu Kaicheng, Zong Yuan, Yu Jian, Xu Huan, Shi Jiemei, Wei Jiaojiao, Zhou Xujiao, Jiang Chunhui
Department of Ophthalmology and Vision Science, Eye and ENT Hospital, Fudan University, Shanghai, China.
Key Laboratory of Myopia of State Health Ministry, and Key Laboratory of Visual Impairment and Restoration of Shanghai, Shanghai, China.
Front Mol Neurosci. 2022 Aug 9;15:930599. doi: 10.3389/fnmol.2022.930599. eCollection 2022.
The aim of this study was to investigate the role and mechanism of berberine (BBR) in the protection of injured retinal ganglion cells (RGCs) in diabetic retinopathy (DR).
Experimental diabetic retinopathy rat model was successfully induced by a single intraperitoneal injection of streptozotocin (STZ, 60 mg/kg) in male SD rats with sufficient food and water for 8 weeks. Animals were randomly divided into four groups: (1) non-diabetic, (2) diabetic, (3) diabetic + BBR + PBS, and (4) diabetic + BBR + SR95531. BBR (100 mg/kg) was given daily by gavage to rats in the group (3) and group (4) for 8 weeks, and weekly intravitreal injections were conducted to rats in the group (3) with 5 μL of 1×PBS and rats in the group (4) with 5 μL of GABA-alpha receptor antagonist SR95531 to investigate the underlying mechanisms. The survival and apoptosis of RGCs were observed by fluorescence gold labeling technology and TUNEL staining. Visual function was evaluated by visual electrophysiological examination. Western blotting and immunofluorescence staining were used to analyze the expression of GABA-alpha receptors in RGCs.
In an animal model, BBR can increase the survival of RGCs, reduce RGCs apoptosis, and significantly improve the visual function. The reduction of GABA, PKC-α, and Bcl-2 protein expression caused by DR can be considerably increased by BBR. SR95531 inhibits BBR's protective effect on RGC and visual function, as well as its upregulation of PKC-α and Bcl-2.
BBR is a promising preventive or adjuvant treatment for DR complications, and its key protective effect may involve the regulation of RGC apoptosis through the GABA-alpha receptor/protein kinase C-alpha (GABAAR/PKC-α) pathway.
本研究旨在探讨黄连素（BBR）在糖尿病视网膜病变（DR）中对受损视网膜神经节细胞（RGCs）的保护作用及机制。
通过对雄性SD大鼠单次腹腔注射链脲佐菌素（STZ，60 mg/kg），并在充足食物和水的条件下饲养8周，成功诱导出实验性糖尿病视网膜病变大鼠模型。动物被随机分为四组：（1）非糖尿病组，（2）糖尿病组，（3）糖尿病 + BBR + PBS组，（4）糖尿病 + BBR + SR95531组。对（3）组和（4）组大鼠每日经口灌胃给予BBR（100 mg/kg），持续8周，对（3）组大鼠每周玻璃体内注射5 μL 1×PBS，对（4）组大鼠每周玻璃体内注射5 μL GABA-α受体拮抗剂SR95531，以研究潜在机制。采用荧光金标记技术和TUNEL染色观察RGCs的存活和凋亡情况。通过视觉电生理检查评估视觉功能。采用蛋白质免疫印迹法和免疫荧光染色分析RGCs中GABA-α受体的表达。
在动物模型中，BBR可增加RGCs的存活，减少RGCs凋亡，并显著改善视觉功能。BBR可显著增加DR导致的GABA、PKC-α和Bcl-2蛋白表达的降低。SR95531抑制BBR对RGC和视觉功能的保护作用，以及其对PKC-α和Bcl-2的上调作用。
BBR是一种有前景的DR并发症预防或辅助治疗药物，其关键保护作用可能涉及通过GABA-α受体/蛋白激酶C-α（GABAAR/PKC-α）途径调节RGC凋亡。
