Keratin filament (Stratum corneum) (KRT)

Keratin filaments in the stratum corneum are the primary structural components of the skin's outermost layer, providing a tough, insoluble barrier against environmental insults and water loss (StatPearls, NBK560714). These intermediate filaments, primarily composed of Keratin 1 and Keratin 10 in the suprabasal layers, undergo extensive cross-linking with proteins like loricrin and filaggrin to form the cornified envelope (UniProt, P04264). In various dermatological conditions such as psoriasis and ichthyosis, there is an overproduction or abnormal organization of these filaments, leading to hyperkeratosis and impaired barrier function (PubMed, 17503915). Therapeutic interventions often involve keratolytic agents like salicylic acid or urea, which soften and facilitate the shedding of the stratum corneum by disrupting the hydrogen bonds and protein structures within the keratin matrix. Additionally, retinoids modulate the expression of keratin genes to normalize skin cell turnover and differentiation. Understanding the dynamics of these filaments is crucial for developing treatments for skin disorders characterized by scaling and thickening of the epidermis.

Other names

CytokeratinTonofilamentKeratin 1Keratin 10Intermediate filamentCornified envelope keratin

Keratolytic agents act by disrupting the cohesive forces between keratinocytes and the structural integrity of keratin filaments through the breaking of hydrogen bonds and protein denaturation, thereby promoting desquamation. Retinoids and vitamin D analogs modulate the expression of keratin genes (e.g., KRT1 and KRT10) to normalize epidermal differentiation and reduce hyperkeratosis.