Expression of sarco/endo-plasmic reticulum Ca2+-ATPase type 2 isoforms (SERCA2) in normal human skin and mucosa, and Darier's disease skin

Background The recent report that mutations in ATP2A2 , which encodes the Ca2+ transporting sarco/endo-plasmic reticulum pump type 2 isoforms (SERCA2), cause Darier's disease (DD) suggests that SERCA2 plays an important role in epidermal cell adhesion and differentiation. However, no data exist regarding SERCA2 expression in normal human skin, mucosa and DD. Objectives We have therefore investigated SERCA2 expression in normal human skin (40 samples), oral and vaginal mucosa (13 samples) and DD lesional skin (six samples). Materials and methods These investigations were performed with a mouse monoclonal antibody specific for human SERCA2, using a standard ABC immunoperoxidase technique. Results SERCA2 was expressed in all specimens. SERCA2 expression was pronounced in the subnuclear aspect of basal epidermal keratinocytes, with variable suprabasal expression. SERCA2 expression was also observed in the infundibulum and outer root sheath of hair follicles; germinative and mature cells of sebaceous glands; secretory coil and duct of eccrine glands; apocrine gland cells, and arrector pili muscle. Fibroblasts and blood vessels (endothelium and muscle) expressed SERCA2, whereas nerves did not. SERCA2 expression was observed throughout oral and vaginal mucosa. In DD skin, strong SERCA2 positivity was detected in the basal, suprabasal and acantholytic lesional cells. Perilesional DD skin was comparable to normal skin. Conclusions These findings support the hypothesis that SERCA2 is an important player in cutaneous biology, and provide baseline data that will facilitate the design and interpretation of functional studies of cutaneous SERCA2.