Next-generation sequencing reveals aqueous MicroRNA and piRNA signatures in age-related macular degeneration and...

MicroRNAs (miRNAs) play important roles in the pathogenesis of age-related macular degeneration (AMD), while whether polypoidal choroidal vasculopathy (PCV) represents a subtype of AMD remains controversial. However, the differential small non-coding RNA profiles in aqueous humor (AH) between neovascular AMD (nAMD) and PCV remain insufficiently characterized. Therefore, this study aimed to characterize miRNA and piRNA expression profiles in AH samples from nAMD and PCV patients and to explore the potential involvement of these small non-coding RNAs in angiogenesis-related pathways. AH samples were collected from nine cataract controls, eight treatment-naïve nAMD patients, and eight treatment-naïve PCV patients. Small RNA profiles in AH were analyzed using next-generation sequencing (NGS). Differential expression analysis was performed using DESeq2 with adjustment for age, sex, best-corrected visual acuity (BCVA), intraocular pressure (IOP), batch effects, and quality-control covariates. Target gene prediction, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were subsequently conducted. Selected miRNAs were partially validated by quantitative PCR (qPCR). To further evaluate their potential relevance to angiogenesis, expression levels of selected miRNAs were additionally examined in a laser-induced choroidal neovascularization (CNV) mouse model. A total of 35 differentially expressed miRNAs were identified between nAMD and PCV, including 28 upregulated and 7 downregulated miRNAs. Moreover, 27 and 47 uniquely expressed miRNAs were detected in nAMD and PCV, respectively. Four miRNAs exhibited opposite expression patterns between the two diseases. Functional enrichment analysis revealed significant involvement of Hippo, MAPK, and neurodegeneration-related signaling pathways. qPCR validation confirmed the differential expression of miR-150-5p and VEGF. In the laser-induced CNV mouse model, miR-150-5p showed expression changes consistent with the human AH sequencing results. Distinct miRNA and piRNA expression profiles were identified between nAMD and PCV, suggesting differential molecular mechanisms underlying the two diseases. These findings improve our understanding of AMD and PCV pathogenesis and may provide potential biomarkers for disease differentiation and angiogenesis-related research.