Figure 1

LPS-induced AKI is associated with early development of tissue fibrosis. In a swine model of LPS-induced AKI, Masson trichrome staining (A) revealed extensive collagen deposition at the interstitial level (thin black arrow), along capillaries (zoomed image), and diffuse glomerular thrombi (thick black arrow) after 9 hours from LPS infusion compared with T0 and T9 of the control group. The pictures are displayed at 4× magnification (A, first line) and 10× magnification (A, second line). (C) In basal condition, no α-SMA⁺ cells (green) were localized in the interstitium and within glomeruli (white arrows). A dramatic increase in α-SMA expression was observed at tubulointerstitial level and within glomeruli and the Bowman capsule (white arrow). An early tubulointerstitial expression of α-SMA was found already at 1 hour with LPS injection. Magnification 630×. To-pro 3 was used to counterstain nuclei (blue). The quantitative analyses of Masson trichrome (B) and α-SMA staining (D) were obtained as described in the Methods section and expressed as median ± IQR of at least five independent pigs for each group. The ELISA tests (E, F) showed a significant increase of KIM-1 and cystatin C in swine sera at 6 and 9 hours from LPS administration compared with T0.