Skin barrier components and epidermal keratinocytes

The skin barrier components and epidermal keratinocytes represent the structural and functional unit of the body's outermost defense system (StatPearls, NBK513299). Epidermal keratinocytes undergo a specialized differentiation process called cornification to form the stratum corneum, which consists of protein-rich corneocytes surrounded by a complex lipid matrix of ceramides, cholesterol, and free fatty acids (PubMed, 16352485). This "brick and mortar" structure is essential for maintaining terrestrial life by preventing transepidermal water loss and providing a robust shield against microbial, chemical, and physical insults (NIH, NIAMS). In many dermatological conditions, such as atopic dermatitis and psoriasis, the integrity of this barrier is compromised due to genetic mutations or inflammatory signaling (PubMed, 29355414). Pharmacological interventions typically aim to either physically supplement the barrier with emollients or biochemically influence keratinocyte behavior to restore homeostasis and reduce inflammation. These components also play a role in innate immunity by producing antimicrobial peptides and cytokines that respond to environmental triggers (PubMed, 15373769).

Other names

Epidermal barrierSkin barrierStratum corneumKeratinocyte layerEpidermal keratinocytes

Restoration of lipid bilayer integrity, hydration of the stratum corneum, and modulation of keratinocyte differentiation and proliferation (StatPearls, NBK549477).