Seed sequence polymorphism rs2168518 and allele-specific target gene regulation of hsa-miR-4513.

MicroRNAs (miRNAs) are small post-transcriptional regulators that offer promising targets for treating complex diseases. To this end, hsa-miR-4513 is an excellent candidate as this gene harbors within its conserved heptametrical seed sequence a frequent polymorphism (rs2168518), which has previously been associated with several complex phenotypes. So far, little is known about the biological mechanism(s) underlying these associations. In an initial step, we now aimed to identify allele-specific target genes of hsa-miR-4513. We performed RNA sequencing in a miRNA overexpression model in human umbilical vein endothelial cells transfected with separated hsa-miR-4513 alleles at rs2168518, namely hsa-miR-4513-G and hsa-miR-4513-A. Genes specifically regulated by the rs2168518 alleles were independently verified by quantitative reverse transcription PCR (qRT-PCR), western blot analysis and allele-specific miRNA binding via a luciferase reporter assay. By a text-based search publicly available databases such as Online Mendelian Inheritance in Man and Mouse Genome Informatics were utilized to link target genes of hsa-miR-4513 to previously described phenotypes. Overall, we identified 23 allele-specific hsa-miR-4513 target genes and replicated 19 of those independently via qRT-PCR. Western blot analysis and luciferase reporter assays conducted for an exemplary subsample further confirmed the allele-specific regulation of these genes by hsa-miR-4513. Remarkably, multiple allele-specific target genes identified are linked via text retrieval to several phenotypes previously reported to be associated with hsa-miR-4513. These genes offer promising candidates for ongoing research on the functional pathobiological impact of hsa-miR-4513 and its seed polymorphism rs2168518. This could give rise to therapeutic applications targeting this miRNA.