Figure 4

PPARγ signalling is not altered in cystic kidneys of pioglitazone-treated mice. (a) Raw Ct-values for the expression of Pparg and Hprt (internal housekeeping gene) in wildtype, untreated (i.e. cystic) iKspCre-Pkd1^del kidneys and pioglitazone-treated iKspCre-Pkd1^del kidneys. Higher Ct-values correspond with lower gene expression. Ct-values of 35 and higher are close to the detection limit. Each data point represents the average of three technical replicates of 1 mouse. (b) Gene expression of selected PPARγ target genes in kidneys of wildtype, untreated (i.e. cystic) iKspCre-Pkd1^del mice and pioglitazone-treated iKspCre-Pkd1^del mice. Expression of Acox1, Cd36 and Cpt1a is significantly downregulated in untreated kidneys, when compared to wildtypes. This expression pattern is not corrected upon pioglitazone administration. Hprt expression was used as internal housekeeping gene. Data are shown as fold change compared to wildtype kidneys. Each data point represents the average of three technical replicates of 1 mouse. (c) Western blotting for PPARγ on protein extracts isolated from wildtype positive control tissues (colon and WAT), wildtype kidneys, untreated (i.e. cystic) iKspCre-Pkd1^del kidneys and pioglitazone-treated iKspCre-Pkd1^del kidneys. β-actin protein expression was used as an internal loading control. (d) Western blotting and quantification for PGC1α on protein extracts isolated from wildtype kidneys, untreated (i.e. cystic) iKspCre-Pkd1^del kidneys and pioglitazone-treated iKspCre-Pkd1^del kidneys. β-actin protein expression was used as an internal loading control. (e) Western blotting for PPARγ in protein extracts isolated from kidneys of wildtype mice, rats and human kidney samples, as well as from mouse and rat adipose tissue and human lipoma tissue as positive controls. β-actin protein expression was used as an internal loading control. No quantification of the blots presented in panels (c) and (e) is shown, as the signal intensity is too close to the background levels for an accurate quantification. Samples were run on the same gel, image acquisition for each protein was done separately. The blots presented in panels (c–e) are cropped, the original blots can be found in Supplementary Fig. 6. Data represent mean ± SD. Significance was measured by one-way ANOVA followed by Tukey’s multiple comparisons test. n.s.: non-significant, Ct: cycle threshold, AU: arbitrary units, WT: wildtype, WAT: white adipose tissue, kDa: kilodalton.