Fig. 4. HOXA3 is upregulated in response to injury in angiogenic vessels. (a) In situ hybridization for HOXA3 expression was performed on sections of control (unwounded) mouse skin (original magnification x400). Little or no signal (purple/black) was detected in resting endothelial cells (arrows). Note the strong positive signal in the adjacent hair follicle (h). (b) In situ hybridization in tissue harvested 1 day following administration of a full-thickness incisional wound shows an increase in mRNA expression in vessels immediately adjacent to the site of the wound. (c) By 4 days following wounding, strong signals were visible in endothelial cells of neovessels within the granulation tissue, as well as other (unidentified) cells in the region. (d) Sense strand control at day 4. (e) Semi-quantitative RT-PCR of HOXA3 mRNA levels 7 days following wounding in heterozygous (wt) and diabetic (db/db) mice. 1 kb ladder in lane 1 represents 2 kb, 1.6 kb, 1 kb, 0.5 kb, 0.4 kb, 0.34 kb, 0.3 kb and 0.22 kb (top to bottom). The 900 bp band corresponding to HOXA3 mRNA is abundantly expressed in wild type but not diabetic wound tissue.