Figure 2.

Analysis of skin wounds in wild-type, tPA-deficient, uPA-deficient, uPA;tPA double-deficient and Plg-deficient mice at day 10 after incision. (A) H&E-stained sections of wounds from wild-type (a, b), tPA-deficient (c, d), uPA-deficient (e, f), uPA;tPA double-deficient (g, h) and Plg-deficient mice (i, j). The boxes in a, c, e, g and i are shown in higher magnification in b, d, f, h, and j. Sections of wild-type (a, b) and tPA-deficient mouse wounds (c, d) show a complete multilayered epidermal barrier underneath the wound crust and a newly formed granulation tissue with a small isolated Islets of provisional matrix remaining. A section from a uPA-deficient mouse (e, f) reveals the leading-edge keratinocytes underneath the wound crust (f). A section of a uPA;tPA double-deficient mouse (g, h) reveals migrating keratinocytes surrounded by provisional matrix. Accumulation of amorphous material is observed both in front of, and underneath, the keratinocytes. Similar, but more pronounced accumulations are seen in the sections from Plg-deficient mice (i and j). The straight black arrows in (e, g, i, f, h and j) point to the tip of the leading-edge keratinocytes. (B) Tissue sections of day 7 wounds from wild-type (a) uPA;tPA double-deficient (b) and Plg-deficient (c) mice were stained by double immunofluorescence for cytokeratin 8 (red) and fibrin(ogen) (green). Accumulation of immunoreactivity for fibrinogen was observed underneath the keratinocytes in wild-type (a) and uPA;tPA double-deficient mice (b). In Plg-deficient mice, similar but more pronounced accumulations are seen underneath as well as in front of the keratinocytes (c). The straight white arrows point to the tip of the leading-edge keratinocytes. Bar: Aa, c, e, g and i ∼140 μm; Ab, d, f, h and j ∼35 μm.