Deciphering the role of long noncoding RNA Pvt1 in preclinical models of ADPKD

ABSTRACT Autosomal dominant polycystic kidney disease (ADPKD) is a very common, monogenetic kidney disorder, affecting approximately 300,000 Americans1, 2. ADPKD primarily results from mutations in PKD1 and PKD23. The pathophysiology of ADPKD is incompletely understood and treatment options are limited. Long noncoding RNAs (lncRNA) – defined by a length >200 nucleotides and absence of a long open reading frame – are a class of non-protein-coding RNAs implicated in a range of disease4, 5. They have emerged as an exciting new drug target category for many common conditions6. However, the role of lncRNAs in ADPKD has been understudied. In a recent study, we found that the lncRNA Pvt1 is highly upregulated in mouse and humans with ADPKD7. Pvt1 is a known oncogenic lncRNA that is overexpressed in many cancers and regulates Myc, other transcription factors, and multiple miRNAs, some of which have major functions in ADPKD8- 11. The role of Pvt1 in ADPKD is not known. We developed a Pkd1-mutant mouse metanephric organ culture (MOC) as a cost-effective model to manipulate gene expression and identify targets that modulate cystogenesis7. We discovered that self-complementary adeno-associated virus (scAAV), serotype DJ, is highly effective in transducing epithelial cells of the mouse MOC. We used scAAV/DJ shRNA to knockdown Pvt1 in Pkd1-null MOCs. We noted that knockdown of Pvt1 markedly reduced cyst index and downregulated c-MYC protein levels in Pkd1-null kidneys. Based on these promising findings, we propose the following aims: 1) test whether ablation of Pvt1 ameliorates cystogenesis in mouse ADPKD, and 2) determine the contribution of PVT1 in human ADPKD by silencing PVT1 in kidney organoids derived from PKD1-mutant hESCs. If successful, results from this study will confirm pathogenic upregulation of PVT1 in-vivo ADPKD, which will form the basis of R01 application.