Characterization and differentiation-dependent regulation of secreted phospholipases A in human keratinocytes and in healthy and psoriatic human skin.

Secreted phospholipases A2 (sPLA2) expressed in the skin are thought to be involved in epidermal barrier homeostasis as well as in inflammation. We investigated the expression of the novel sPLA2 subtypes in human skin at mRNA and protein levels in the epidermis and primary keratinocytes from healthy human skin, and in skin sections from patients with psoriasis, where the integrity of the epidermis is drastically affected. Immunofluorescence studies using specific antibodies for the different sPLA2 enzymes show that sPLA2-IB, -IIF, and -X are predominantly expressed in suprabasal layers, whereas sPLA2-V and -IID are detected in the basal and spinous layers.

Differentiation-dependent regulation of secreted phospholipases A2 in murine epidermis.

The action of secreted phospholipases A2 in skin is thought to be essential for epidermal barrier homeostasis. The incomplete knowledge of presence and functions of the novel secreted phospholipase A2 subtypes in skin prompted us to explore their expression in epidermis and primary keratinocytes from murine neonatal skin. We detected secreted phospholipases A2-IB, -IIA, -IIC, -IID, -IIE, -IIF, -V, -X, and -XII.