背景:色素性视网膜炎(RP)是指一组进行性光感受器退行性疾病。据报道,小胶质细胞的激活在RP视网膜的光感受器变性中起重要作用。布京益士片(BJYS),一种中草药,在中国已用于治疗视网膜疾病,在改善视功能方面效果理想。然而,BJYS治疗RP疗效的潜在机制尚不完全清楚.
目的:在初步实验的基础上,本研究旨在探讨BJYS治疗N-甲基-N-亚硝基脲(MNU)诱导的RP视网膜变性的治疗机制。
方法:为了探讨BJYS的疗效,通过腹腔注射MNU(50mg/kg)建立大鼠实验性RP模型。进行了两个实验。治疗后,我们进行了H&E,TUNEL,小胶质细胞中视网膜细胞因子水平和IBA-1表达证实对RP模型的影响。通过蛋白质印迹评估BJYS片的具体作用机制,实时聚合酶链反应(RT-PCR),和免疫荧光来确定参与阐明通过P2X7R/CX3CL1/CX3CR1途径发挥的BJYS有效性的mRNA和蛋白质表达水平。
结果:在MNU诱导的RP大鼠的视网膜中观察到BJYS处理显著减轻视网膜形态结构和光感受器变性,BJYS阻止了ONL厚度的降低,并降低了ONL中凋亡细胞的水平。它还抑制小胶质细胞过度激活和降低视网膜IL-1β水平,IL-6、TNF-α。此外,BJYS降低了P2X7、CX3CL1和CX3CR1的蛋白表达和mRNA表达,降低了p38MAPK的磷酸化。
结论:总之,这项研究表明,BJYS治疗可以通过P2X7R/CX3CL1/CX3CR1通路抑制小胶质细胞过度激活和炎症,从而减轻RP的光感受器变性。这些作用表明BJYS片剂可以作为RP的有希望的口服治疗剂。
BACKGROUND: Retinitis pigmentosa (RP) refers to a group of progressive photoreceptor degenerative diseases. The activation of microglia has been reported to play an important role in the photoreceptor degeneration in RP retinal. Bujing Yishi tablets (BJYS), a Chinese herbal medicine, has been used to treat retinal diseases in China with desirable effect in improving visual function. However, the mechanisms underlying the efficacy of BJYS treatment in RP are not yet fully understood.
OBJECTIVE: Based on the preliminary experiments, this study aimed to investigate the therapeutic mechanism involved in treating N-Methyl-N-Nitrosourea (MNU)-induced retinal degeneration of RP with BJYS.
METHODS: To explore the efficacy of BJYS, a rat experimental RP model was established through intraperitoneal injection of MNU (50 mg/kg). Two experiment was carried out. After the treatment, we conducted H&E, TUNEL, retinal cytokine levels and IBA-1 expression in microglia to confirm the impact on RP model. The specific mechanism of action of BJYS tablet was assessed by western blot, real-time polymerase chain reaction (RT-PCR), and immunofluorescence to determine the mRNA and protein expression levels involved in clarifying the effectiveness of BJYS exerted through P2X7R/CX3CL1/CX3CR1 pathway.
RESULTS: Significant alleviation of retinal morphological structure and photoreceptor degeneration by BJYS treatment was observed in the retinal of MNU-induced RP rats, BJYS prevented the reduction of ONL thickness and decreased the level of apoptotic cells in ONL. It also inhibited microglia overactivation and reduced retinal levels of IL-1β, IL-6, TNF-α. In addition, BJYS decreased the protein expression and mRNA expression of P2X7, CX3CL1 and CX3CR1 and reduced the phosphorylation of p38 MAPK.
CONCLUSIONS: In summary, this study suggested that BJYS treatment could alleviate photoreceptors degeneration of RP by inhibiting microglia overactivation and inflammation through the P2X7R/CX3CL1/CX3CR1 pathway. These effects suggest that BJYS tablets may serve as a promising oral therapeutic agent for RP.