Figure 2. Roscovitine slows cyst growth in Cep164^cKO kidneys.

(A) Schematic of timeline of roscovitin injections and kidney analysis.

(B) Overview of kidney morphology of vehicle treated control (ctrl) and Cep164^cKO kidneys at P14. Scale bar 5mm.

(C) Overview of kidney morphology of roscovitine (150 mg/kg) treated control (ctrl) and Cep164^cKO kidneys at P14. Scale bar 5mm.

(D) Roscovitine treatment reduces the kidney weight to body weight ratio in P14 Cep164^cKO mice. Vehicle 2.76 ± 0.10, n=5, vs. roscovitine 1.79 ± 0.15, n=6, ***p<0.001.

(E – H) Comparison of hematoxylin and eosin-stained mid-sagittal sections of vehicle treated (E,G) and roscovitine-treated kidneys (F,H) demonstrate a significant reduction in the size of the cortical collecting duct cysts in roscovitine-treated P14 Cep164^cKO kidneys.

(I) Cystic index is significantly reduced in P14 Cep164^cKO kidneys after roscovitin treatment. Vehicle 52.25 % ± 1.15 %, n=4 vs. roscovitine 28.92 % ± 1.68 %, n=7, **** p<0.0001.

(J) Roscovitine treatment blocks cell cycle activity in Cep164^cKO kidneys. Western blotting against markers of cell cycle activity pRb, PCNA, pERK1/2, cyclin A and cyclin D1 are significantly decreased in roscovitine-treated Cep164^cKO kidneys at P14 compared to vehicle-treated kidneys. Erk1 and Gapdh are used as loading controls. Phospho-proteins were compared with total protein or GAPDH as loading control for densitometric analysis which is presented graphically in i, ii, iii and iv. i) pRb ctrl vs cKOveh (1 ± 0.2, n=3 vs. 3.6 ± 0.7, n=3), cKOveh vs. cKOros (3.4 ± 0.7, n=3 vs. 0.9 ± 0.0, n=3, *p<0.05); ii) cyclinA ctrl vs. cKOveh (1 ± 0.1, n=3 vs. 2.6 ± 0.1, n=3, **p<0.01), cKOveh vs. cKOros (2.6 ± 0.1, n=3 vs. 1.3 ± 0.1, n=3, **p<0.01); iii) pErk1 ctrl vs. cKOveh (1 ± 0.1, n=3 vs. 4.8 ± 0.6, n=3, **p<0.01), cKOveh vs. cKOros (4.8 ± 0.6, n=3 vs. 2.8 ± 0.2, n=3, *p<0.05); iv) cyclinD1 ctrl vs. cKOveh (1 ± 0.2, n=3 vs. 7.8 ± 0.9, n=3, **p<0.01), cKOveh vs. cKOros (7.8 ± 0.9, n=3 vs. 2.7 ± 0.4, n=3, **p<0.01). Data from 3 individual animals in a given group were used for densitometric analysis.