Fig. 4: Tlr4^−/− mice demonstrate increased wound healing and blood flow post-injury.

Tlr4^−/− demonstrate increased wound closure compared to C57BL/6 mice. This is enhanced in the presence of rhPRG4 a. Representative images of ears 4 weeks post-injury b, c. The black dashed line represents the plane of histological sectioning which the original injury diameter, while the white dashed box indicates the location of the histological image presented b, c. Histological images stained with Safranin O, 4 weeks post-injury d, e, with the black dashed line representing the original injury site. New immature cartilage can be observed in Tlr4^−/− mice treated with DMSO (arrows, d). Although the wound is nearly closed, minimal cartilage islands are observed in Tlr4^−/− mice treated with rhPRG4 (arrow e). Quantitative analysis of blood flow data demonstrates that Tlr4^−/− mice treated with DMSO or rhPRG4 show increased blood flow at the wound area post-injury f. The number of CD31 + blood vessels are also increased in the wound area site of Tlr4^−/− mice (g). MEFs from Tlr4^−/− mice demonstrate higher baseline levels of VEGF and do not increase the in presence of rhPRG4 h, i. Scale bar equals 500 µm. n.s. = not significant. Error bars equal mean ± SD (f–h – 1 way ANNOVA, a – 2 way ANNOVA). Sample sizes: a–f, n = 15 per group; g–i, n = 6 per group.