Identification of micro RNAs in regions of the genome with rare structural variants as potential genetic drivers of congenital anomalies of the kidney and urinary tract in humans

[K. M. Mitrović]

81 str.

Biologija - Genetika / Biology - Genetics

Urođene anomalije bubrega i urinarnog trakta (engl. Congenital anomalies of the kidney and urinary tract – CAKUT) su najčešći uzročnik terminalne bubrežne insuficijencije kod dece koja vodi hemodijalizi i transplantaciji bubrega. Retki CNV regioni su među najčešćim genetičkim varijantama koje su povezane sa nastankom CAKUT-a. Međutim, uloga miRNK čiji su geni lokalizovani u ovim regionima nije ispitana u kontekstu genetičkih uzročnika nastanka CAKUT-a. Glavni cilj ove studije bio je identifikacija i funkcionalna interpretacija miRNK koje su najčešće lokalizovane u CNV regionima koji su asocirani sa CAKUT-om. Bioinformatičkom analizom pokazano je da 80% pacijenata sa CAKUT-om ima u identifikovanim retkim CNV regionima bar jedan gen koji kodira miRNK. Analiza mreže miRNK, koje su najčešće lokalizovane u retkim CNV regionima koji su asocirani sa CAKUT-om, pokazala je dominantnu regulaciju dve miRNK, hsa-miR-484 i hsa-miR-185-5p. Funkcionalna studija pokazala je značajnu promenu u ekspresiji ovih miRNK u HEK293 ćelijskim linijama sa homozigotnom ili heterozigotnom delecijom gena za pomenute miRNK u odnosu na WT ćelijske linije, kao i promenu u ekspresiji njihovih ciljnih gena. Restitucijom nivoa hsa-miR-484 i hsa-miR-185-5p u ćelijskim linijama sa uvedenom homozigotnom ili heterozigotnom delecijom gena za miRNK potvrđen je potencijal ublažavanja efekta retkog CNV regiona na ekspresiju ciljnih gena miRNK koje su lokalizovane u ovim regionima. Ovo istraživanje ukazuje da bi izmenjena ekspresija ciljnih gena usled delecije gena za miRNK izazvane retkim CNV regionima mogla predstavljati jedan od mehanizama nastanka i fenotipske varijabilnosti CAKUT-a.

Congenital anomalies of the kidney and urinary tract (CAKUT) are the most common cause of end-stage renal disease in children, which leads to hemodialysis and kidney transplantation. Rare CNV regions are among the most common genetic variants underlying CAKUT. However, the role of miRNAs located in these regions has not been investigated in the context of genetic drivers of CAKUT. The main aim of this study was the identification and functional interpretation of miRNAs located in CNV regions associated with CAKUT. Bioinformatic analysis showed that 80% of CAKUT patients have at least one miRNA gene in the identified rare CNV regions. Network analysis of miRNAs, which are most often located in rare CNV regions associated with CAKUT, showed a dominant regulation of two miRNAs, hsa-miR-484 and hsa-miR-185-5p. A functional study showed a significant change in the expression of these miRNAs in HEK293 cell lines with homozygous or heterozygous gene deletion for the mentioned miRNAs compared to WT cell lines, as well as a change in the expression of their target genes. Restitution of hsa-miR-484 and hsa-miR-185-5p levels in cell lines with introduced homozygous or heterozygous deletion of miRNA genes confirmed the potential to alleviate the effect of rare CNV regions on the expression of miRNA target genes located in these regions. This study indicates that altered expression of miRNA target genes due to deletion of miRNA genes caused by rare CNV regions could represent one of the mechanisms of the occurrence and phenotypic variability of CAKUT.

Bioinformatika, Mikro RNK, CNV regioni, miRNK mimike, Ekspresija gena

Bioinformatics, Micro RNA, CNV regions, miRNA mimics, Gene expression

577.2:616.-007(043.3)

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