Microscopic appearance of incision wounds, shown perpendicular to the longitudinal direction of the wound, of control and Fib^−/− mice.

(A) Normal epithelial cell migration below the eschar in a control mouse 3 days after wounding. (B) Complete re-epithelialization of a control mouse at 6 days. (C) Altered pattern of epithelial cell ingrowth observed in Fib^−/− mice on day 3 with the leading edge of epithelial cells proceeding down the dermal wound edge into a sinus (s) formed at the edge of the wound bed, and away from the center of the wound. (D) Re-epithelialization in a Fib^−/−mouse 6 days after injury by unification of epithelium that had previously followed the dermal face into a prominent sinus (s). (E) Epithelial hyperplasia commonly observed at the leading edge of 5-day-old wounds of Fib^−/− mice. (F) Fusion of an abnormally hyperplastic endothelium in a Fib^−/− mouse (day 7) leaving a persistent sinus below the epithelium. (G) Partial re-epithelialization in a Fib^−/− mouse (day 4) by “paving” the entire inner surface of a wound sinus. (H) Re-epithelialization in a Fib^−/− mouse (day 7) with the formation of a spur (arrowheads). Epithelium is indicated with arrows; gaps, or sinuses, in the wound field are indicated with an “s.” Panels A-D, G, and H: original magnification 40×. Panels E and F, original magnification 100×. Hematoxylin and eosin stain.