Na-Cl Cotransporter (SLC12A3) Inhibition Exacerbates Age-Related Macular Degeneration Via the Nrf2/HO-1 Ferroptosis Pathway.

Purpose: To explore the causal links between antihypertension drugs usage and age-related macular degeneration (AMD).

Methods: Multiple genetic analyses, including summary data-based Mendelian randomization (SMR), traditional MR, and colocalization analysis, were used to explore the causal associations between antihypertension drugs and AMD. Clinical data from the UK Biobank and the National Health and Nutrition Examination Survey (NHANES) was applied to refined risk assessment of specific antihypertensive medications in the context of AMD development. In vitro and in vivo oxidative stress models, mediated by NaIO3, were utilized to study the impact of specific antihypertensive drugs and target genes on AMD pathogenesis.

Results: Genetic analyses substantiated the causal relationship between increased SLC12A3 expression and a lowered AMD risk. Colocalization analysis supported the shared causal attributes between SLC12A3 expression and AMD. Cross-sectional analysis results based on UK Biobank indicated that AMD risk was significantly lower in participants taking thiazide diuretics with other antihypertensives or not on antihypertensives compared to those on thiazides alone. The results based on NHANES support the above results. In vivo and in vitro experiments showed that thiazide diuretics worsened retinal damage in AMD mouse models, and SLC12A3 knockdown disrupted the balance of oxidative stress in retinal pigment epithelium (RPE) cells. Further molecular mechanism experiments showed that SLC12A3 knockdown promoted retinal degeneration by regulating RPE ferroptosis through activation of the Nrf2/HO-1 pathway.

Conclusions: Our study underscores a notable causal association between thiazide diuretic use and AMD risk and reveals a potential mechanism by which inhibition or downregulation of SLC12A3 (sodium-chloride cotransporter [NCC]) contributes to AMD progression. However, deeper exploration is needed to enhance the accuracy and validity of our findings.