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Background: Regulated alteration of connexin expression has been shown to be integral to acute wound repair. Downregulation of the gap-junction protein connexin 43 at the wound edge has been correlated with keratinocyte and fibroblast migration, while abnormal overexpression of connexin 43 significantly perturbs healing, as shown in the streptozotocin diabetic rodent impaired healing model., Objectives: To examine the protein expression levels of connexin 43, in addition to connexins 26 and 30, in a variety of human chronic wounds., Methods: Wound-edge punch biopsies and a matched control from the arm were taken from a cohort of patients with venous leg, diabetic foot or pressure ulcers. Wound connexin expression in each patient was compared with that in a matched, nonwounded arm punch. Tissue was sectioned, stained and imaged by confocal microscopy using identical parameters per patient to permit quantification., Results: Epidermal connexin 43, connexin 26 and connexin 30, and dermal connexin 43 were discovered to be strikingly upregulated in every ulcer from all three wound types, pointing to connexin upregulation as a common feature between chronic wounds., Conclusions: This result supports efforts to target connexin 43 to promote cell migration and wound healing in chronic ulcers., (© 2015 British Association of Dermatologists.)

Carcinoembryonic antigen (CEA) is recognized as being important not only as a tumour marker, but also as a cell adhesion molecule in the metastasis of malignant tumour cells, and in the development of inflammatory disorders in some organs. However, the role played by this antigen in inflammatory dermatoses has not been studied previously. To investigate the expression of CEA in inflamed skin, we performed immunohistochemical studies to detect the antigen in both frozen and formalin-fixed, paraffin-embedded biopsy specimens of inflammatory dermatoses, using five different monoclonal antibodies and one polyclonal antibody against human CEA or CEA-related molecules. CEA and CEA-related antigens were expressed by epidermal keratinocytes and by some infiltrating inflammatory cells in inflamed skin. The expression was observed primarily in the upper part of the malpighian layers of the epidermis. On the basis of the distribution of this expression, we suggest an additional role for CEA-related molecules, differing from their roles as tumour markers and adhesion molecules, namely that these molecules may be associated with the state of differentiation of epidermal keratinocytes. Unexpected expression of CEA-related antigens was seen on normal follicular keratinocytes. Thus, it is conceivable that CEA-related antigen may also play a role in the biology of hair follicles.

In congenital deficiency of leucocyte-adherence glycoproteins (CDLG) there is an immunodeficiency with impaired leucocyte function and cutaneous and extracutaneous infections occur. In more than 30% of cases the condition has a fatal course. We report the skin manifestations of three siblings with CDLG in which areas of skin necrosis occurred that resembled pyoderma gangrenosum.

Non-enzymatic glycosylation of keratin from the stratum corneum of the sole of the foot was measured by the thiobarbituric acid technique in thirty diabetic and thirty control subjects. A significant increase in the level of glycosylation was demonstrated in the diabetic subjects (P less than 0.001). HbA1 levels were measured in a further eighteen subjects at the same time as keratin was removed, and in this group a significant association between non-enzymatic glycosylation of that protein and diabetic control was demonstrated (P less than 0.01). In vitro incubation of keratin in the presence of free glucose produced increased non-enzymatic glycosylation (P less than 0.01) and this effect was blocked by incubation in the presence of increasing concentrations of aspirin (P less than 0.01). Measurement of non-enzymatic glycosylation of keratin in a further group of twenty diabetics with neuropathic ulceration showed a significant increase in levels when compared with a group of diabetics without ulcers (P less than 0.05). As keratin is the principle structural protein of the stratum corneum of the sole of the foot, it is possible that changes in this protein associated with non-enzymatic glycosylation may contribute to abnormalities seen in the skin of the feet of diabetics.