Fig. 1: rhPRG4 simulates regeneration of ear wound injury.

rhPRG4 treatment results in near total closure of the ear wound 4 weeks-post injury, while Prg4^−/− demonstrate no wound closure. This is rescued by the addition of rhPRG4 a. Photographs of the representative ears 4 weeks post-injury b–e. The black dashed line represents the plane of histological sectioning, the parallel black bars represent the original injury diameter b–e, while the white dashed box indicates the location of the histological image presented b–e. Representative histological images stained with Safranin O, 4 weeks post-injury f–i. Mainly fibrotic-like tissue was observed in the injury site of C57BL/6 and Prg4^−/− mice treated with DMSO f, h. In Prg4^−/− mice treated with rhPRG4, new cartilage like-tissue can be observed in the injury site (arrow g). New cartilage bridging the injury site can be observed in C57BL/6 mice treated with rhPRG4 and only small areas are present that still lack cartilage (arrows i). The black dashed line represents site of original injury Scale bar equals 50 µm. n.s. = not significant. Sample sizes: a-i, n = 15 per group. Error bars equal mean ± SD (a - 2 way ANNOVA).