Characterisation of transcription factor profiles in polycystic kidney disease (PKD): identification and validation of STAT3 and RUNX1 in the injury/repair response and PKD progression

Abstract

Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic renal disease, caused in the majority of the cases by a mutation in either the PKD1 or the PKD2 gene. ADPKD is characterised by a progressive increase in the number and size of cysts, together with fibrosis and distortion of the renal architecture, over the years. This is accompanied by alterations in a complex network of signalling pathways. However, the underlying molecular mechanisms are not well characterised. Previously, we defined the PKD Signature, a set of genes typically dysregulated in PKD across different disease models from a meta-analysis of expression profiles. Given the importance of transcription factors (TFs) in modulating disease, we focused in this paper on characterising TFs from the PKD Signature. Our results revealed that out of the 1515 genes in the PKD Signature, 92 were TFs with altered expression in PKD, and 32 of those were also implicated in tissue injury/repair mechanisms. Validating the dysregulation of these TFs by qPCR in independent PKD and injury models largely confirmed these findings. STAT3 and RUNX1 displayed the strongest activation in cystic kidneys, as demonstrated by chromatin immunoprecipitation (ChIP) followed by qPCR. Using immunohistochemistry, we showed a dramatic increase of expression after renal injury in mice and cystic renal tissue of mice and humans. Our results suggest a role for STAT3 and RUNX1 and their downstream targets in the aetiology of ADPKD and indicate that the meta-analysis approach is a viable strategy for new target discovery in PKD. Key messages & We identified a list of transcription factors (TFs) commonly dysregulated in ADPKD. & Out of the 92 TFs identified in the PKD Signature, 35% are also involved in injury/repair processes. & STAT3 and RUNX1 are the most significantly dysregulated TFs after injury and during PKD progression. & STAT3 and RUNX1 activity is increased in cystic compared to non-cystic mouse kidneys. & Increased expression of STAT3 and RUNX1 is observed in the nuclei of renal epithelial cells, also in human ADPKD samples.

Endothelial progenitor cells-derived exosomal microRNA-21-5p alleviates sepsis-induced acute kidney injury by inhibiting RUNX1 expression

“…A study has purported that the expression of RUNX1 is markedly enhanced in renal fibrosis 16 . It has been demonstrated that RUNX1 expression is notably heightened in the nuclei of renal epithelial cells, also in human autosomal dominant polycystic kidney disease samples 25 It is reported that miR-21-5p is highly enriched in EPCs-exosomes 26 . It was reported by our study that exosomes raised miR-21-5p and decreased RUNX1 in renal tissues.…”

Runx1 shapes the chromatin landscape via a cascade of direct and indirect targets

“…Runx1 regulates EMT in other tissues [44][45][46][47]. While the role of Runx1 during kidney development is unknown, it is activated in kidney during injury and repair where it may contribute to several disease processes [23,[48][49][50][51], including cancer [52,53], in which it may collaborate with Runx2 [54] to drive EMT associated with worse outcomes. The profound consequences of Runx1 loss to the mK4 transcriptome suggests that a further delineation of its role in the kidney may be warranted.…”

Inhibiting Runx1 protects heart function after myocardial infarction

“…Whether expression of Runx1 alters propensity for arrhythmias warrants future investigation. With regards to non-cardiac diseases, increased RUNX1 expression is a key contributor to retinal vascular dysfunction 44 , liver disease 52 , septic shock 53 and kidney dysfunction 54 . In support of our work on the therapeutic potential of RUNX1 inhibitors in the setting of myocardial infarction, Ro5-3335 has been successfully used to improve both cardiac 55 and non-cardiac related diseases 56 .…”