Figure 2
CD26 is upregulated in differentiating keratinocytes. (a, b) WT (a) and InvEE skin (b) labelled with anti-CD26 (red) and DAPI nuclear counterstain (blue). (e) epidermis; (d) dermis; dashed lines: epidermal–dermal boundary. (c) CD26 and involucrin expression in stratified keratinocytes. Extended focus of Z-stack in XY plane showing DAPI-stained nuclei (white), CD26 (green) and involucrin (magenta). Red line (left hand panel) indicates plane of XZ projection (right hand panels). Arrows: basal and suprabasal cell nuclei. (d) CD26 enzymatic activity of cultured WT and InvEE mouse keratinocytes±1.8 mM calcium ions and 10 ng/ml IL-1α (mean±s.d.; n=3). Keratinocytes were transferred from low-calcium medium to 1.8 mM of CaCl2 and/or treated with 10 ng/ml IL-1α for 3–5 days. Scale bars: 50 μm.
