Skin epidermis is an active site of
lipid synthesis. The intercellular
lipids of human stratum corneum (SC) are unique in composition and quite different from the
lipids found in most
biological membranes. The three major
lipids in the SC are
free fatty acids,
cholesterol and
ceramides.
Fatty acids can be synthesized by keratinocytes de novo and, in addition, need to be taken up from the circulation. The latter process has been shown to be
protein mediated, and several
fatty acid transporters are expressed in skin. Recent studies of transgenic and knockout animal models for
fatty acid transporters and the identification of
fatty acid transport protein 4 (FATP4 or SLC27A4) mutations as causative for
Ichthyosis Prematurity Syndrome highlight the vital roles of
fatty acid transport and metabolism in skin homeostasis. This review provides an overview of our current understanding of the role of
fatty acids and their transporters in cutaneous biology, including their involvement in epidermal barrier generation and skin
inflammation.