Figure 4. Spontaneous inflammation, tubule injury, renal failure, and death in Kim1^RECtg mice.

(A) Periodic acid-schiff stain of control or Kim1^RECtg kidneys between 2 and 44 weeks of age reveals no difference in histology at 2 weeks, but progressive interstitial mononuclear cell infiltration, tubule dilation, epithelial simplification and interstitial expansion in Kim1^RECtg kidneys only at later time points. Scale bar, 50 μm. (B) Tubule cast and injury scores rise with age in Kim1^RECtg kidneys (n = 3) compared with littermate controls (n = 3). *P = 0.001, **P = 0.0009, NS (not significant). (C) Serum creatinine begins to rise between 3 and 5 weeks and rises progressively in Kim1^RECtg kidneys (n = 4–8 per time point) compared with controls (n = 5–11 per time point), *P = 0.002, **P = 0.006, ***P = 0.004. (D) A Kim1^RECtg kidney is markedly reduced in size and fibrotic at 10 weeks compared with littermate control kidney. (E) Kim1^RECtg mice die spontaneously at a median age of 11 weeks (n = 20, both groups), P < 0.0001.