OBJECTIVETo investigate the time course of changes in the expression of fibroblast activation protein (FAP) during healing of skin scald burns in rats.

METHODSAdult Wistar rats were randomized into two equal groups (n=42) and subject to superficial second degree and deep second degree scald burns on the dorsal skin groups, with 6 normal rats serving as the control group. At 6 h, 12 h, and 1, 3, 7, 14, and 21 days after burns, 6 rats from each group were sacrificed to detect FAP expression by immunohistochemistry and Western blotting.

RESULTSFAP was expressed on the cell membrane and in the cytoplasm of the fibroblasts, especially those around the neovessels. In both burn groups, FAP expression increased significantly at 6 h after burns. In superficial burn group, FAP expression was comparable between 6 and 12 h and between 1 and 3 days (P>0.05), but showed significant differences between the other time points (P<0.05). In deep burn group, FAP expression was comparable between 12 h, 1 day and 3 days (P>0.05) but differed significantly between the other time points (P<0.05). In both burn groups, FAP expression reached the peak level at 7 days followed by a gradual declination. At 21 days after the burns, FAP maintained a significantly higher expression level than the control level (P<0.05).

CONCLUSIONThe time course of the changes of FAP expression following scald burns suggests an important role of FAP in the healing process of scald burns.