[Cutaneous lipids: from physiology to the clinical]

Area of Science:

• Dermatology and skin biology
• Lipid metabolism and biochemistry

Context:

• The epidermis forms a vital barrier against the environment, primarily through the stratum corneum.
• Epidermal lipids, particularly glycosylceramides, are essential precursors for stratum corneum ceramides, which maintain skin barrier integrity and corneocyte cohesion.

Purpose:

• To elucidate the role of epidermal lipids, including glycosylceramides and ceramides, in skin barrier formation and epidermal differentiation.
• To understand how alterations in lipid synthesis and secretion contribute to skin disorders.

Summary:

• Extracellular glycosylceramides are transformed into ceramides, vital for corneocyte cohesion and barrier function.
• Cholesterol sulfate is converted to cholesterol, and intracellular ceramides are involved in epidermal terminal differentiation.
• Imbalances in epidermal lipid synthesis or secretion can result in genetic or environmentally influenced skin diseases.

Impact:

• Highlights the critical role of epidermal lipid metabolism in maintaining skin health.
• Provides insights into the pathogenesis of various skin disorders linked to lipid abnormalities.
• Underscores the importance of understanding lipid pathways for potential therapeutic interventions in dermatology.