Objective: We aim to investigate circulating genome-wide microRNA (miRNome) profiles in Moyamoya disease-discordant monozygotic (MZ) twins with the RNF213 founder mutation (rs112735431), since the etiology remains unclear even after the identification of RNF213.
Methods: Circulating miRNome was screened in a pair of Moyamoya-discordant MZ twins and a validation cohort (unrelated 9 cases and 8 normal controls) using microarray and validated by quantitative real-time PCR. Differential plasma microRNAs were quantified in endothelial cells differentiated from iPS cell line (iPSECs) derived from unrelated 3 cases and 3 controls. Gene expressions targeted by the significant microRNAs in iPSECs was studied using published iPSEC-transcriptome and bioinformatics tool.
Results: A total of 537 circulating microRNAs were detected in the Moyamoya-discordant MZ twins and the validation cohort. Unsupervised cluster analysis demonstrated 2 discrete miRNome, predominantly by disease, but the MZ twins showed similar miRNome profiles, regardless of phenotypic discordance (Fig. 1A). Across the 143 and 98 differential microRNAs in the MZ twins and validation cohort, 23 microRNAs were overlapped (Fig. 1B). A cluster of plasma hsa-miR-6722-3p/-328-3p/150-5p was significantly up-regulated in patients in the validation cohort (p < 0.05) (Fig. 1C). In iPSECs, hsa-miR-6722-3p/-328-3p cluster was up-regulated with a greater than 3.0-fold change in patients. Bioinformatics analysis revealed that 94 target genes involving organismal injuries and cell survival/maintenance were significantly down-regulated in Moyamoya-iPSECs (p < 0.05, q < 0.1), suggesting the regulatory role of the miR-6722/-328 cluster in endothelial gene expression (Fig. 1D).
Conclusions: Differential plasma-miRNAs in Moyamoya-discordant MZ twins may potentially serve as a diagnostic biomarker in Moyamoya disease and regulate endothelial gene expression.