Expression of tight-junction proteins in the inflamed and clinically uninvolved skin in patients with venous leg ulcers

Skin around venous leg ulcers (VLUs) is often inflamed and prone to contact sensitization. Expression of tight-junction components (ZO-1, occludin, and claudins 1 and 4) was studied by immunofluorescence in inflamed and noninflamed lower leg skin (both uncovered skin and skin occluded under hydrocolloid dressings) in patients with VLUs. No major differences were found in the expression of occludin and claudin-4. ZO-1 protein had stronger and more wide-ranging expression in the inflamed epidermis. Expression of claudin-1 was lost from the basal layer of the inflamed skin and skin under the hydrocolloid dressing. The skin on the lower legs affected by VLU may have altered expression of ZO-1 and claudin-1, similar to that seen in psoriatic plaques.