Assessment of fibrosis in nephrotoxic nephritis. Representative images showing collagen IV staining in glomeruli of Tmsb4x+/y (a), Tmsb4x+/y + nephrotoxic serum (NTS) (b), and Tmsb4x−/y + NTS (c) mice. (d) Quantification of collagen IV (Col4a1) mRNA levels in whole-kidney homogenates of Tmsb4x+/y (n = 8), Tmsb4x+/y + NTS (n = 9), and Tmsb4x−/y + NTS (n = 6) mice. Representative images showing α-smooth muscle actin (α-SMA) staining in glomeruli of Tmsb4x+/y (e) Tmsb4x+/y + NTS (f) and Tmsb4x−/y + NTS (g) mice. (h) Quantification of α-SMA (Acta2) mRNA levels in whole-kidney homogenates of Tmsb4x+/y (n = 8), Tmsb4x+/y + NTS (n = 8), and Tmsb4x−/y + NTS (n = 5) mice. Data are presented as mean ± SEM. *P ≤ 0.05, **P ≤ 0.01. Bar = 20 μm. Tmsb4x, thymosin β4.