RNA Sequencing and Targeted Knockdown Reveal miR-142a-5p as a Driver of Retinal Degeneration in rd1 Mice

Retinitis pigmentosa (RP), an inherited retinal disorder, leads to progressive photoreceptor degeneration and irreversible blindness, with limited treatment options available. Emerging evidence implicates microRNAs (miRNAs) in the pathogenesis of retinal disease, yet understanding of their specific roles in RP remains incomplete. In this study, we employed high-throughput RNA sequencing to profile miRNA expression in a rd1 RP mouse model at postnatal day 14. Our analysis revealed 40 upregulated and 27 downregulated miRNAs in rd1 retinas compared to controls. Notably, miR-142a-5p, miR-223-3p, and miR-653-5p were significantly elevated, while miR-25-3p was downregulated. Given miR-142a-5p's established roles in apoptosis and inflammation, we investigated its contribution to retinal degeneration. Knockdown of miR-142a-5p in rd1 mice improved retinal function and preserved outer nuclear layer thickness, suggesting a protective effect against photoreceptor loss. These findings highlight miR-142a-5p as a key regulator of RP progression and a promising therapeutic target for mitigating vision loss in retinal degenerative diseases.