414 Exogenous ceramide serves as a precursor to endogenous ceramide synthesis and as a modulator of keratinocyte differentiation

Abstract

Since ceramide (Cer) is a key epidermal barrier constituent and its deficiency causes barrier-compromised skin, several molecular types of Cer are formulated in commercial topical agents to improve barrier function. Topical Cer localizes on the skin surface and in the stratum corneum, but certain amounts of Cer penetrate into the stratum granulosum, becoming precursors to endogenous Cer synthesis following molecular modification. Moreover, exogenous Cer as a lipid mediator could modulate keratinocyte proliferation/differentiation.