Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China.
Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China.
Biochim Biophys Acta Mol Cell Res. 2024 Oct;1871(7):119802. doi: 10.1016/j.bbamcr.2024.119802. Epub 2024 Jul 26.
Very-low-density lipoprotein receptor (VLDLR) involves in ocular neovascularization, a major cause of severe vision loss. However, the underlying molecular mechanisms were not completely clarified. Here, we aimed to investigate roles of circular RNAs (circRNAs) in VLDLR-associated ocular neovascularization.
Vldlr knockout (Vldlr-/-, ko), Robo4 knockout (Robo4-/-, ko) and wild-type (WT) mice were used. Mouse model of oxygen induced retinopathy (OIR) and high-throughput sequence were performed to profile the differential expression of circRNA and transcripts. RNase R treatment, Sanger PCR sequencing and quantitative polymerase chain reaction (qPCR) were used to validate candidate circRNAs and their expression patterns. Choroidal sprouting assay ex vivo and laser induction choroid neovascularization were used to determine the expression and functions of QKI/CircSlc17a5 on choroidal neovascularization.
In macrophage and ocular tissues derived from Vldlr (Vldlr-/-,Vldlr ko) or Robo4 (Robo4-/-,Robo4 ko) deficiency as well as wild-type (WT) mice, Quaking (Qki) expression was significantly down-regulated in Vldlr deficiency compared to WT and Robo4 deficiency groups. Ectopic VLDLR expression or Reelin stimulation increased expression of QKI in bEnd.3 cells. Circular RNA sequencing uncovered that VLDLR regulated the biogenesis of certain circular RNAs, including the circSlc17a5. The number of Circular RNAs increased in mice treated with OIR. QKI mediated the biogenesis of circSlc17a5, which was an important regulator of choroidal angiogenesis.
CircSlc17a5 regulated by VLDLR/QKI plays important roles in the choroidal angiogenesis.
极低密度脂蛋白受体（VLDLR）参与眼部新生血管形成，这是严重视力丧失的主要原因。然而，其潜在的分子机制尚不完全清楚。本研究旨在探讨环状 RNA（circRNA）在 VLDLR 相关眼部新生血管形成中的作用。
使用 Vldlr 基因敲除（Vldlr-/-，ko）、Robo4 基因敲除（Robo4-/-，ko）和野生型（WT）小鼠。进行氧诱导视网膜病变（OIR）模型和高通量测序以分析 circRNA 和转录本的差异表达。使用 RNase R 处理、Sanger PCR 测序和实时定量聚合酶链反应（qPCR）验证候选 circRNA 及其表达模式。在体外脉络膜发芽实验和激光诱导脉络膜新生血管化实验中，检测 QKI/CircSlc17a5 在脉络膜新生血管化中的表达和功能。
在巨噬细胞和来源于 Vldlr（Vldlr-/-，Vldlr ko）或 Robo4（Robo4-/-，Robo4 ko）缺失以及野生型（WT）小鼠的眼部组织中，与 WT 和 Robo4 缺失组相比，Vldlr 缺失组中 Quaking（Qki）的表达明显下调。外源性 VLDLR 表达或 Reelin 刺激增加了 bEnd.3 细胞中 QKI 的表达。环状 RNA 测序揭示 VLDLR 调节了某些环状 RNA 的生物发生，包括 circSlc17a5。在 OIR 治疗的小鼠中，环状 RNA 的数量增加。QKI 介导 circSlc17a5 的生物发生，这是脉络膜血管生成的重要调节因子。
受 VLDLR/QKI 调控的 circSlc17a5 在脉络膜血管生成中发挥重要作用。
