Serum microRNA profile of ADPKD patients

From serum samples of non-dialyzed and dialyzed patients with ADPKD and healthy control total RNA was isolated and miRNA expression was evaluated. Circulating microRNAs (miRNA) are important intercellular communication compounds. We investigated the influence of ADPKD (autosomal dominant polycystic kidney disease) and hemodialysis on the profile of serum miRNAs. We found 37 significant circulating miRNA that differ between ADPKD patients (dialyzed and non-dialyzed) and healthy controls. Bioinformatic analysis revealed strongest connections between those miRNAs and KEGG pathway: MicroRNAs in cancer. We selected 3 miRNAs with highest and 3 with lowest fold change in comparison of dialyzed and non-dialyzed patients and compared their expression in paired pre-/post-dialysis samples. All up-regulated miRNAs (miR-532-3p, miR-320b, miR-144-5p) were not significantly altered by hemodialysis. From down-regulated miRNAs miR-27a-3p was shown to be significantly lower after dialysis in both total and exosomal fraction. MiR-20a-5p was down-regulated after dialysis only in the exosomal fraction whereas miR-16-5p was unaltered by hemodialysis. MiR-16-5p was selected as the best circulating biomarker of ADPKD with miR-22-3p, let-7i-5p and miR-24-3p as following best ones. Circulating representatives of miR-17 family (new drug target of ADPKD (Hajarnis et al. 2017)) sharing the same seed region (miR-20a-5p, miR-93-5p and miR-106a-5p) showed significantly lowered expressed in sera of dialyzed patients vs non-dialyzed ones and their exosomal fraction dropped after hemodialysis. We concluded that serum miRNA among ADPKD patients differ substantially depending on the stage of CKD. These alterations show possible links with cancer. The exosomal fraction of miRNA was more affected by dialysis than total fraction of miRNAs suggesting their dynamically changing functional role. RT-PCR microRNA expression profiling in serum (Exiqon real-time PCR human miRNA arrays I and II (miRCURY LNA)) in 10 patients with ADPKD on hemodialysis treatment, 10 patients with ADPKD without hemodialysis treatment and 10 healthy controls.