Figure 4.

A: Wound immaturity in CXCR3^−/− mice is reflected in persistence of select extracellular matrix proteins. As the scar develops and matures, MMP-9 expression decreases in the wounds in wild-type mice, yet in the CXCR3^−/− mice strong expression is still present in high levels as late as day 180 after wounding. Staining of provisional matrix proteins tenascin C and fibronectin shows continued enhanced expression in wounds of CXCR3^−/− mice in contrast to the wild-type mice that at 180 days after wounding closely resemble the negligible expression seen in normal skin. Collagen I and Collagen III levels in wounds of CXCR3^−/− resemble those seen in hypertrophic scarring, as did the elevated levels of decorin. B: Hydroxyproline levels in wounds in CXCR3^−/− mice are significantly increased compared with those in wild-type (WT) mice. Representative micrographs (n = 6 for each mouse genotype per time point). Scale bar = 50 μm. *P < 0.05.