Cai Chunyang, Gu Chufeng, Meng Chunren, Wang Yujie, Wei Qingquan, He Shuai, Lai Dongwei, Wang Xingyun, Wang Tengfei, Qiu Qinghua
Department of Ophthalmology, Tong Ren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China.
Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China.
Clin Epigenetics. 2025 May 17;17(1):82. doi: 10.1186/s13148-025-01874-4.
This study aims to elucidate the effect and mechanism of phospholipid transfer protein (PLTP) on vascular dysfunction in DR and explore the molecular mechanism of abnormal PLTP expression based on DNA methylation.
Human retinal microvascular endothelial cells (HRMECs) cultured in high glucose (HG) and streptozotocin-treated mice were used as DR models to detect and screen the key genes with abnormal promoter DNA methylation. Single-cell sequencing, tube formation and migration assays were employed to verify the relationship between PLTP and vascular function. Additionally, siRNA and luciferase reporter assay were used to study the key enzymes regulating the DNA methylation of PLTP. Transcriptome sequencing, coimmunoprecipitation and GSK3β inhibitor were utilized to identify and validate the key downstream pathways of PLTP.
DR models exhibited DNA hypermethylation and decreased expression of PLTP. Abnormal PLTP expression was implicated in vascular dysfunction, and PLTP overexpression reversed HG-induced effects on the migration and tube formation of endothelial cells. The siDNMT3B and luciferase reporter assay indicated that DNMT3B is the primary enzyme affecting abnormal methylation. Interestingly, PLTP promoted the phosphorylation of AKT and GSK3β, indicating that PLTP modulates angiogenesis via the AKT/GSK3β signaling pathway.
PLTP regulates the proliferation, migration and tube formation of HRMECs, and is involved in maintaining vascular function via the AKT/GSK3β signaling pathway. In HG environment, increased DNMT3B expression upregulates DNA methylation of the PLTP promoter, downregulating PLTP expression and leading to vascular dysfunction in DR.
本研究旨在阐明磷脂转运蛋白（PLTP）对糖尿病视网膜病变（DR）血管功能障碍的影响及机制，并基于DNA甲基化探讨PLTP异常表达的分子机制。
将在高糖（HG）环境中培养的人视网膜微血管内皮细胞（HRMECs）和经链脲佐菌素处理的小鼠作为DR模型，检测并筛选启动子DNA甲基化异常的关键基因。采用单细胞测序、管腔形成和迁移实验来验证PLTP与血管功能之间的关系。此外，使用小干扰RNA（siRNA）和荧光素酶报告基因实验研究调节PLTP DNA甲基化的关键酶。利用转录组测序、免疫共沉淀和糖原合成酶激酶3β（GSK3β）抑制剂来鉴定和验证PLTP的关键下游通路。
DR模型表现出DNA高甲基化以及PLTP表达降低。PLTP异常表达与血管功能障碍有关，PLTP过表达可逆转HG对内皮细胞迁移和管腔形成的影响。siDNMT3B和荧光素酶报告基因实验表明，DNA甲基转移酶3B（DNMT3B）是影响异常甲基化的主要酶。有趣的是，PLTP促进了蛋白激酶B（AKT）和GSK3β的磷酸化，表明PLTP通过AKT/GSK3β信号通路调节血管生成。
PLTP调节HRMECs的增殖、迁移和管腔形成，并通过AKT/GSK3β信号通路参与维持血管功能。在HG环境中，DNMT3B表达增加上调了PLTP启动子的DNA甲基化，下调PLTP表达，导致DR中的血管功能障碍。
