Figure 9.

Nrg3 signaling perturbs the expression of basement membrane components and stem cell markers. (A and B) β1-integrin is expressed along the basement membrane (indicated by an arrow) throughout the basal epidermis of non-transgenic littermate (A). β1-integrin expression is reduced in the K14-Nrg3 transgenic epidermis (B). (C and D) α6-integrin is expressed along the basement membrane throughout the basal epidermis of non-transgenic littermate (C and E). α6-integrin expression is reduced in the K14-Nrg3 transgenic epidermis (D and F). The basement membrane expression is indicated by an arrow. Some regions of intact basement membrane are present with normal levels of α6-integrin expression, indicated by dashed line, adjacent to regions where α6-integrin expression is reduced. (G and H) Tenascin-C is expressed along the basement membrane in the vicinity of hair follicles of non-transgenic littermate and is indicated by an arrow (G). Tenascin-C is expressed along the basement membrane throughout the K14-Nrg3 transgenic basal epidermis (H). Strong Tenascin-C staining expression is observed at the dermal-epidermal junction and is indicated by an arrow. (I and J) p63 expression is restricted to epidermal and hair follicle cells with high proliferative potential and is absent in cells undergoing terminal differentiation. p63 expression is restricted to most basal cells and a few suprabasal cells in the IFE and ORS of non-transgenic littermates (I). p63 is expressed throughout most of the basal K14-Nrg3 epidermis (J) with expanded expression detected in up to four suprabasal cell layers. The scale bar represents 50 μm except in (E and F) where it represents 12.5 μm.