Effect of beta-catenin (Ctnnb1) on vasopressin-responsive gene expression in mouse kidney collecting duct mpkCCDc11 cells

Vasopressin tightly regulates water reabsorption in renal collecting duct cells by increasing the abundance of aquaporin-2 (AQP2) through transcriptional and post-transcriptional mechanisms. We recently discovered that a complex comprising CTNNB1 (beta-catenin) and PARP1 involves Aqp2 gene transcription in response to vasopressin as a transcriptional regulator. However, the mechanistic involvement of Ctnnb1 in Aqp2 gene transcription in response to vasopressin is poorly known. To understand Ctnnb1-mediated Aqp2 gene regulation in the collecting duct cells, RNA sequencing (RNA-seq)-based transcriptomic profiling was perfomred in mouse kidney collecting duct cell line mpkCCDc11 treated with dDAVP or Ctnnb1 knockdown. Overall design: The mpkCCDc11 cells transfected with control-siRNA (50 nM) or Ctnnb1-siRNA (50 nM) were grown on semipermeable supports (6-well transwell, 3450, Corning Costar) for 4 days and starved in serum- and hormone-free medium for an additional 24 h before dDAVP treatment. After treatment with dDAVP (1 nM) for 24 h, total RNA was extracted for RNA-Seq analysis. The experimental groups are 1) control-siRNA with vehicle treatment; 2) control-siRNA with dDAVP treatment; 3) Ctnnb1-siRNA with vehicle treatment; 4) Ctnnb1-siRNA with dDAVP treatment.