Skin stratum corneum lipids and desmosomal intercellular junctions (SC lipids and corneodesmosomes)

The skin stratum corneum lipids and desmosomal intercellular junctions (specifically corneodesmosomes) constitute the primary physical and chemical barrier of the human epidermis. The lipids, composed mainly of ceramides, cholesterol, and free fatty acids, form a lamellar matrix that prevents transepidermal water loss and protects against environmental insults (StatPearls, NBK513299). Corneodesmosomes are specialized protein complexes that provide structural cohesion between corneocytes, and their regulated degradation by kallikrein-related peptidases is essential for healthy desquamation (Journal of Investigative Dermatology, 120(5)). Together, these components maintain the brick-and-mortar structure of the skin, where corneocytes are the bricks and the lipid-rich matrix and junctions are the mortar and rivets. Dysfunction in these components is a hallmark of various dermatological conditions, including atopic dermatitis and ichthyosis, where barrier impairment leads to inflammation and infection (PubMed, 16910014). Therapeutic interventions often involve the topical application of physiological lipids to restore the barrier or keratolytic agents to facilitate the breakdown of junctions in hyperkeratotic states (PubMed, 24656726).

Other names

Stratum corneum barrierIntercellular lipid matrixCorneodesmosomesSkin barrier componentsCorneocyte-lipid matrix

Barrier restoration through lipid replenishment; Keratolysis via enzymatic or chemical degradation of corneodesmosomes; Occlusion to reduce transepidermal water loss