Xie Lulu, Zhang Ru, Hu Chunjie, Li Ting, Zhang Zhao-Peng, Jin Mei-Ying, Gao Rui, Zhang Zhi-Run, Zheng Wei, Ju Yuan, Guo Jun-Peng
Changchun University of Traditional Chinese Medicine, Chang Chun, China.
Affiliated Hospital of Changchun University of Traditional Chinese Medicine, Changchun, China.
Exp Eye Res. 2025 May;254:110329. doi: 10.1016/j.exer.2025.110329. Epub 2025 Mar 8.
This study conducted an experiment to scrutinize the effect of phlorizin (Phl) on diabetic retinopathy (DR) and to delve into the related molecular mechanisms. Within this investigation, DR was induced in rats with diabetes mellitus (DM) by subjecting them to a regimen involving a high-fat and high-sugar diet, coupled with intraperitoneal administration of streptozotocin (STZ) at a dosage of 45 mg/kg. Retinal damage in DR rats was assessed by means of hematoxylin and eosin (HE) staining. The serum levels of inflammatory and angiogenic factors were also measured. Additionally, the levels of tight junction proteins, angiogenic proteins, and inflammatory proteins in the retinas of DR model rats were assessed using Western blot (WB),immunohistochemistry(IHC) and immunofluorescence(IF). Moreover, bioinformatics and network pharmacology methodologies were utilized to pinpoint intersecting genes linked to DR and to elucidate the mechanism of action of Phl. This involved screening with Venny, conducting Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG)analyses, constructing a Protein-Protein Interaction (PPI) network, and performing molecular docking analysis. The results of this study demonstrated that Phl significantly normalized fasting glucose levels and reduced body weight, thereby alleviating obesity in DR rats after 12 weeks. Furthermore, the serum levels of inflammatory and angiogenic factors were considerably reduced in the drug-treated rats. WB, IHC and IF revealed increased expression of the tight junction proteins zonula occludens-1(ZO-1) and occludin in the retinas of drug-treated DR rats, validating the observed findings. Molecular biology validation experiments based on the predictions by network pharmacology indicated a substantial decrease in the expression levels of vascular endothelial growth factor (VEGF), notch homolog 1 (Notch1), and hypoxia inducible factor-1 (HIF-1α) in the retina upon treatment with Phl. This reduction resulted in the inhibition of neovascularization. Furthermore, Phl exhibited inhibitory effects on inflammatory pathways, leading to a decrease in cytokine release. The overexpression of VEGF was identified as a factor diminishing brain-derived neurotrophic factor(BDNF) expression while increasing the expression levels of inflammatory proteins. Therefore, the results of this research demonstrate that Phl has the potential to protect the retina of DR rats by inhibiting VEGF expression. This protective effect may be associated with the modulation of the VEGF/BDNF/NF-κB signaling pathway.
本研究进行了一项实验，以探究根皮苷（Phl）对糖尿病视网膜病变（DR）的影响，并深入研究相关分子机制。在本研究中，通过给糖尿病（DM）大鼠喂食高脂高糖饮食，并腹腔注射剂量为45mg/kg的链脲佐菌素（STZ）来诱导DR。通过苏木精-伊红（HE）染色评估DR大鼠的视网膜损伤。还测量了炎症和血管生成因子的血清水平。此外，使用蛋白质免疫印迹（WB）、免疫组织化学（IHC）和免疫荧光（IF）评估DR模型大鼠视网膜中紧密连接蛋白、血管生成蛋白和炎症蛋白的水平。此外，利用生物信息学和网络药理学方法来确定与DR相关的交集基因，并阐明Phl的作用机制。这包括使用Venny进行筛选、进行基因本体论（GO）和京都基因与基因组百科全书（KEGG）分析、构建蛋白质-蛋白质相互作用（PPI）网络以及进行分子对接分析。本研究结果表明，Phl显著使空腹血糖水平正常化并减轻体重，从而在12周后减轻DR大鼠的肥胖。此外，药物治疗组大鼠的炎症和血管生成因子血清水平显著降低。WB、IHC和IF显示，药物治疗的DR大鼠视网膜中紧密连接蛋白闭合蛋白1（ZO-1）和闭合蛋白的表达增加，证实了观察结果。基于网络药理学预测的分子生物学验证实验表明，用Phl治疗后，视网膜中血管内皮生长因子（VEGF）、Notch同源物1（Notch1）和缺氧诱导因子-1（HIF-1α）的表达水平大幅下降。这种下降导致新生血管形成受到抑制。此外，Phl对炎症途径具有抑制作用，导致细胞因子释放减少。VEGF的过表达被确定为一个降低脑源性神经营养因子（BDNF）表达同时增加炎症蛋白表达水平的因素。因此，本研究结果表明，Phl具有通过抑制VEGF表达来保护DR大鼠视网膜的潜力。这种保护作用可能与VEGF/BDNF/NF-κB信号通路的调节有关。
