Serum MicroRNAs as Potential Biomarkers of AMD

BACKGROUND: Age-related macular degeneration (AMD) is a major cause of blindness worldwide. Circulating microRNAs (miRNAs) in serum have emerged as novel candidate biomarkers for many diseases. The aim of the present study was to identify a serum microRNA (miRNA) expression profile specific for dry and wet forms of AMD.
MATERIAL AND METHODS: Serum miRNA expression was first screened using TaqMan® Human MicroRNA Array A (Applied Biosystems). An extensive, self-validated, individual, quantitative RT-PCR (qRT-PCR) study was then performed on a cohort of 300 AMD patients (150 wet form and 150 dry form) and 200 controls. The Mann-Whitney U test and nonparametric Spearman’s rank correlation coefficient were used for statistical analysis.
RESULTS: miRNA expression analysis revealed increased expression of miR661 and miR3121 in serum of patients with dry AMD and miR4258, miR889, and Let7 in patients with wet form. Expression of analyzed miRNA was not observed or remained at low level in controls.
CONCLUSIONS: Differences in miRNA serum profile exist between patients with wet and dry form of AMD, which indicates miRNAs as potential biomarkers of AMD. Further studies should be performed to confirm its significance in clinical practice.

Keywords: Biomarkers - blood, Case-Control Studies, Gene Expression Profiling, Gene Expression Regulation, Macular Degeneration - genetics, MicroRNAs - blood, Oligonucleotide Array Sequence Analysis, Polymerase Chain Reaction, Reverse Transcriptase Polymerase Chain Reaction, Vascular Endothelial Growth Factor A - metabolism, Vascular Endothelial Growth Factor Receptor-2 - metabolism