Progression of CKD in Col4a3 KO and Col4a3;Tsp1 DKO mice. A: Representative photomicrographs of MTS-stained kidney sections of wild-type C57BL/6 control, Col4a3 KO, and Col4a3;Tsp1 DKO mice at 6, 12, 22, and 32 weeks. Col4a3 KO mice did not live to 32 weeks of age. B: Serum creatinine levels of wild-type C57BL/6, Tsp1 KO, Col4a3 KO mice, and Col4a3;Tsp1 DKO mice over time. Data are expressed as means ± SEM. Original magnification, ×10. CKD, chronic kidney disease; DKO, double knock-out; ESRF, end-stage renal failure; KO, knock-out; MTS, Masson’s trichrome stain.