Figure 4.

Interstitial fibrosis induced by UUO is significantly more severe in Mrc2-deficient mice. Compared with wild-type mice (Mrc2^+/+), mice genetically engineered to express a mutant Mrc2 gene missing exons 2–6, which includes the collagen-binding domain (Mrc2^−/−), have significantly higher total kidney collagen levels 14 and 21 days after UUO (A). Worse fibrosis was confirmed by computer-assisted image analysis of picrosirius red+ interstitial areas (B). Representative polarized light photomicrographs illustrate more extensive interstitial collagen fibril accumulation in the Mrc2^−/− mice (C) compared with the Mrc2^+/+ mice (D). Bar graphs represent results expressed as mean ± SD, n=9–11 mice per group. ^†P<0.05 for Mrc2^−/− versus Mrc2^+/+ groups. The photomicrographs are magnified ×400.