Human keratinocyte (HK)

Human keratinocytes are the primary cellular component of the epidermis, making up approximately 90% of the outermost layer of the skin. They play a critical role in maintaining the body's structural integrity and providing a protective barrier against environmental stressors, pathogens, and UV radiation through the process of keratinization and the formation of the stratum corneum. In addition to their structural functions, keratinocytes are immunologically active cells that produce various cytokines and chemokines in response to injury or infection, contributing to the inflammatory landscape of skin diseases like psoriasis and dermatitis. While keratinocytes are the site of action for many dermatological treatments, the term 'Human keratinocytes' refers to a cell type rather than a specific molecular target such as a receptor or enzyme. Therefore, they are typically utilized in pharmaceutical research as a cellular model for drug screening and toxicity testing rather than being classified as a target molecule itself.

Other names

KeratinocyteEpidermal cellBasal cell (when in basal layer)Prickle cell (when in stratum spinosum)

Not applicable as a molecular mechanism; however, drugs modulate keratinocyte behavior via receptors like the Retinoic Acid Receptor (RAR), Vitamin D Receptor (VDR), or by blocking cytokines (IL-17, IL-4/13) that act upon these cells.