AAV2.7m8-Mediated MicroRNA Expression Suppresses VEGF-Induced Angiogenic Responses in HUVEC

Area of Science:

• Ophthalmology and Molecular Biology
• Gene Therapy and Drug Delivery

Background:

• Pathological angiogenesis driven by vascular endothelial growth factor (VEGF) causes neovascular diseases such as nAMD and DR.
• Current anti-VEGF treatments require frequent intravitreal injections due to short intraocular half-life, necessitating long-term therapeutic strategies.

Purpose of the Study:

• To evaluate the anti-angiogenic potential of retinal organoid-derived microRNAs (miRNA) delivered via an engineered adeno-associated virus (AAV) vector.
• To assess the efficacy of AAV-mediated miRNA delivery in suppressing VEGF-induced signaling and angiogenic responses in vitro.

Main Methods:

• Human umbilical vein endothelial cells (HUVEC) were transduced with AAV2.7m8 vectors to overexpress miR-26a, miR-122, and let-7a.
• Cells were stimulated with VEGF to evaluate downstream signaling pathways (ERK, JNK, p38 MAPK phosphorylation) and angiogenic responses (proliferation, migration, tube formation).

Main Results:

• AAV2.7m8 transduction was efficient and non-cytotoxic.
• Overexpressed miRNAs significantly attenuated VEGF-induced phosphorylation of key MAPK signaling proteins.
• All three miRNAs inhibited endothelial cell proliferation and capillary-like tube formation; miR-122-5p also inhibited migration.

Conclusions:

• AAV2.7m8-mediated delivery of retinal organoid-derived miRNAs (miR-26a-5p, miR-122-5p, let-7a-5p) effectively suppresses VEGF-induced angiogenic signaling and endothelial cell activation in vitro.
• This miRNA delivery system shows promise as a sustained therapeutic approach for pathological retinal neovascularization.