functional targets of cilia dependent cyst activation (CDCA) and a potential therapeutic targets for treating polycystic kidney disease

We applied unbiased cell type specific transcriptional profiling by translating ribosome affinity purification (TRAP) to mouse kidneys with polycystin-1 and cilia inactivation at a stage prior kidney tubule cyst formation. We identified differentially expressed actively translating mRNA that correlated with the cilia dependent cyst activation (CDCA) pattern common to male and female mice. This differential translatome offers opportunities for mechanistic discovery in polycystin and cilia related kidney phenotypes. Overall design: We performed TRAP RNASeq at a stage when cyst formation had not yet occurred following Pkd1 inactivation. To achieve these objectives, we used mice with the following genotypes: Pkd1fl/+; R26Rpl10a; Pax8rtTA; TetOCre (“noncystic”), Pkd1fl/fl; R26Rpl10a; Pax8rtTA; TetOCre (Pkd1KO), Pkd1fl/fl; Kif3afl/fl; R26Rpl10a; Pax8rtTA; TetOCre (Pkd1KO+ciliaKO). All experimental mice were hemizygous for the R26Rpl10a, Pax8rtTA and TetOCre alleles. The R26Rpl10a allele expresses the L10a-EGFP ribosomal protein fusion23 following expression of Cre recombinase in response to doxycycline, allowing selective pulldown of ribosomes only from nephron epithelial cells in which Pax8rtTA is expressed. All mice received oral doxycycline from postnatal day 28 to 42 (P28–P42) to induce TetOCre. Fresh kidney tissue was harvested for ribosomal pulldown at P49 (7 weeks).