Table 5_Targeting mitophagy in diabetic retinopathy: novel insights into SQSTM1/BNIP3L pathway regulated by luteolin.xls

ObjectiveDiabetic retinopathy (DR) is a leading microvascular complication of diabetes. Luteolin, a flavonoid with known anti-inflammatory and antioxidant properties, has demonstrated therapeutic potential in early investigations for the treatment of DR. However, its precise molecular mechanisms remain inadequately defined. This study aimed to explore the local and systemic immunological mechanisms underlying luteolin’s therapeutic effects on DR.
MethodsKey regulatory genes and cell subpopulations were identified from single-cell RNA sequencing (scRNA-Seq) datasets derived from peripheral blood mononuclear cells (PBMCs) and retinal tissues of DR patients. The molecular interactions were analyzed using molecular docking simulations. Reactive oxygen species (ROS) were quantified through DCFDA assays, while retinal structural damage was assessed using Hematoxylin and eosin (H&E) and Periodic Acid-Schiff (PAS) staining. Comprehensive analyses, including enzyme-linked immunosorbent assays (ELISA), immunofluorescence, immunohistochemistry, and Western blotting were conducted to evaluate cytokine levels and protein expression.
ResultsThe study revealed that luteolin exerted protective effects against DR primarily by activating mitophagy and reducing oxidative stress, with the SQSTM1/BNIP3L pathway emerging as a critical mediator. Furthermore, a novel mechanistic link was established between monocyte activity and DR progression, highlighting the VISFATIN signaling pathway’s role in immune cell regulation and its contribution to disease pathology.
ConclusionThis study offers novel insights into the luteolin’s therapeutic potential in DR, particularly activating mitophagy through the SQSTM1/BNIP3L axis, which expands the scope of natural compounds in addressing this sight-threatening complication of diabetes.

糖尿病视网膜病变（Diabetic retinopathy, DR）是糖尿病最主要的微血管并发症。木犀草素（Luteolin）是一类已知兼具抗炎与抗氧化特性的黄酮类化合物，早期研究已证实其在糖尿病视网膜病变治疗中具备潜在应用价值，但其确切分子机制仍未被充分阐明。本研究旨在探究木犀草素治疗糖尿病视网膜病变的局部与全身免疫调控机制。

本研究从糖尿病视网膜病变患者外周血单个核细胞（peripheral blood mononuclear cells, PBMCs）和视网膜组织的单细胞RNA测序（single-cell RNA sequencing, scRNA-Seq）数据集中筛选关键调控基因与细胞亚群；采用分子对接模拟分析分子间相互作用；通过2',7'-二氯荧光素二乙酸盐（DCFDA）实验定量检测活性氧（reactive oxygen species, ROS）水平；采用苏木精-伊红（Hematoxylin and eosin, H&E）染色与过碘酸雪夫（Periodic Acid-Schiff, PAS）染色评估视网膜结构损伤；通过酶联免疫吸附测定（enzyme-linked immunosorbent assays, ELISA）、免疫荧光（immunofluorescence）、免疫组织化学（immunohistochemistry）以及蛋白质印迹（Western blotting）等综合实验手段，评估细胞因子水平与蛋白表达情况。

本研究发现，木犀草素主要通过激活线粒体自噬、减轻氧化应激发挥抗糖尿病视网膜病变的保护作用，其中SQSTM1/BNIP3L通路为关键介导因子。此外，本研究揭示了单核细胞活性与糖尿病视网膜病变进展之间的全新机制关联，明确了烟酰胺磷酸核糖转移酶（VISFATIN）信号通路在免疫细胞调控中的作用及其对疾病病理进程的贡献。

本研究为木犀草素治疗糖尿病视网膜病变的潜在价值提供了全新见解，尤其是其通过SQSTM1/BNIP3L轴激活线粒体自噬的机制，拓展了天然化合物用于治疗这一致盲性糖尿病并发症的应用范围。