Increased endocan expression in lesional skin and decreased endocan expression in sera in atopic dermatitis

Endocan is a novel human endothelial cell-specific molecule and is mainly expressed in endothelial cells in various tissues. Endocan has the capacity to inhibit leukocytes binding to the vascular endothelium. It also can promote the angiogenesis alongside vascular endothelial growth factor A. Through these functions, endocan has been implicated in the pathogenesis of various inflammatory diseases. To investigate the possible roles of endocan in atopic dermatitis (AD), we examined endocan expression in lesional skin and sera in patients with AD. Endocan mRNA and protein levels were increased in lesional skin of AD compared with healthy skin and endocan was expressed on epidermal keratinocytes and dermal endothelial cells. On the other hand, serum endocan levels in patients with AD were significantly lower than those in healthy controls. Our results suggest that elevated endocan expression in lesional skin may be associated with development of AD through angiogenesis and that decreased endocan expression in sera may be associated with increased leukocyte recruitment in AD.