Keratin and other superficial epidermal proteins (KRT)

Keratins are a family of fibrous structural proteins that constitute the primary intermediate filaments in epithelial cells, particularly within the stratum corneum of the epidermis (UniProt, 2024). These proteins, alongside other superficial components such as filaggrin, loricrin, and involucrin, are essential for maintaining the skin's mechanical integrity and its role as a semi-permeable barrier against environmental pathogens and dehydration (NIH, 2023). In various dermatological disorders, including psoriasis, ichthyosis, and seborrheic dermatitis, there is an abnormal accumulation or defective organization of these proteins, resulting in hyperkeratosis and scaling (PubMed, 2022). Therapeutic strategies targeting these proteins primarily utilize keratolytic agents, such as salicylic acid and urea, which facilitate the breakdown of keratin and the dissolution of the intercellular cement holding corneocytes together (StatPearls, 2023). This action promotes the shedding of the outer skin layers, thereby smoothing the skin surface and improving the absorption of concurrent topical medications. Furthermore, the presence of keratin serves as a substrate for dermatophyte infections, making its management relevant in treating fungal conditions of the skin and nails (NIH, 2024).

Other names

CytokeratinEpidermal structural proteinsCornified envelope proteinsIntermediate filament proteinsCorneocyte proteins

Drugs targeting these proteins typically act via keratolysis, which involves the dissolution of the intercellular cement (desmosomes) holding keratinocytes together and the direct softening or degradation of keratin filaments through the disruption of hydrogen bonds, thereby facilitating the shedding of the stratum corneum (StatPearls, 2023).