Cornification

The document describes cornification as a specialized form of programmed cell death that transforms metabolically active epidermal keratinocytes into corneocytes, which are dead skin cells that form the body's barrier to the environment. This process involves the breakdown of organelles, cross-linking of proteins, and maintenance of intercellular connections, regulated by enzymes such as proteases, transglutaminases, and DNases. Disruptions in skin homeostasis can lead to abnormal keratinocyte cornification, and genetic defects in cornification can result in skin diseases. Understanding cornification is important for diagnosing these conditions and improving dermatological treatments. The document also notes that cornification is crucial for the skin barrier in terrestrial vertebrates and compares it to other forms of programmed cell death.