Abstract
Purpose :
We aim to determine the therapeutic role of miR-15a-5p on fundus neovascularization and reveal its advantages in comparison to anti-VEGF therapy.
Methods :
PCR measured miR-15a-5p levels in plasma, plasma sEVs, and vitreous of NDM, DM, NPDR and PDR patients. OIR and CNV models were used to study the effect of intravitreal miR-15a-5p on neovascularization. Retinal structure and function were analyzed using OCT and ERG, comparing the results with anti-VEGF treatment. Inflammatory and pro-fibrotic changes were assessed with WB, PCR, and immunofluorescence. Systemic safety assessments were performed, covering body weight, blood markers, and liver/kidney structure. MiR-15a-5p knockout mice were used to verify the inhibitory effect on neovascularization. In vitro experiments involved HRMECs, RPE cells, and rMC-1 cells, with TGF-β inducing endothelial-mesenchymal transition and inflammatory activation in rMC-1 cells. PCR, WB, and dual-luciferase assays confirmed miR-15a-5p's direct regulation of smad2 and VEGF.
Results :
MiR-15a-5p was elevated in NPDR and PDR patients' plasma sEVs and vitreous, but not in plasma. In OIR and CNV models, miR-15a-5p inhibited neovascularization similarly to anti-VEGF treatment, but improved retinal non-perfusion area recovery better. Compared to anti-VEGF, miR-15a-5p reduced Müller cell activation, decreased retinal inflammation, promoted vascular attachment to astrocytes, and facilitated reconstruction. MiR-15a-5p knockout mice showed enhanced neovascularization, which could be reversed by miR-15a-5p injection. Additionally, miR-15a-5p improved retinal structure/function and was safer than anti-VEGF in growing mice. MiR-15a-5p inhibited TGFβ-induced endothelial cell proliferation/transition and suppressed Müller cell activation and VEGF secretion. Dual-luciferase assays confirmed miR-15a-5p directly down-regulated VEGF and smad2.
Conclusions :
MiR-15a-5p decreases retinal neovascularization, supports normal vascular growth, reduces inflammation/fibrosis, and is safer than anti-VEGF for mouse body development and lipid metabolism. MiR-15a-5p may be a potential treatment for pathological neovascularization.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.