Diabetic Foot Ulcers and Epidermal Growth Factor: Revisiting the Local Delivery Route for a Successful Outcome

Figure 2

EGF receptor (EGFR) and prohibitin expression along the longitudinal axis of granulation tissue collected from neuropathic diabetic foot ulcer. Three strata ((1)–(3), where (1) is the wound surface) along the longitudinal axis of the biopsy material (approximately 2 mm/strata and 6 mm depth) were clearly distinguished according to the type of cellularity and the spreading, intensity, and definition of the immunolabelling. (a) Prohibitin expression. Prohibitin is a well-characterized protein involved in cell cycle arrest. As shown, the peroxidase-derived brownish label is far more concentrated on the wound surface (layer (1)). (b) EGFR expression. Recognition of EGFR phosphorylated on tyrosine residue 1197 indicates downstream signaling activation, prevailing in layer (3). As noticeable, EGFR expression is absent from the wound surface layer. Thus, an inverse expression pattern is shown for both markers which suggests the differential biological response of the cells of each layer. A representative aspect of each stratum was photographed and composed as in the slide. Summing up, EGFR immunostaining prevails at the wound bottom and not in its surface. In contrast prohibitin appears far more expressed on the wound surface. Pictures were obtained at ×40 constant magnification.

(a)

(b)