Ceramides (For Professionals)

Ceramides are part of the 3 main lipid types in the skin:

• ceramide
  • backbone:long aminoalcohol chain (C16-24)= cer (sphingoid base + fatty acid)
  • 12 types identified

• cholesterol

• free fatty acids

Roles of lipids in the skin

• constituents of cell membranes (plasma, cellular organelle)
• lipid droplets (adipocytes in fat and sequestration of toxic lipids (protection from cell death)

• epidermal barrier
  • essential for survival
  • lipids unique to skin
  • epidermal permeability barrier lipids
  • the epidermal barrier is located in the stratum corneum SC in lamellar structures (lamellar bodies)

Synthesis of ceramides (and epidermal lipids in general)

• lipid synthesis in the stratum granulosum (SG)
• lipid packaging (between the SG and the stratum corneum (SC))
• lipid secretion and processing in the SC

Diseases related to anomalies in the synthesis of epidermal lipids in general (of which ceramides are a part of)

• Atopic Dermatitis
  • anomalies in lipid processing (strtum corneum) and ceramide (lipid) synthesis (stratum granulosum)

• Harlequin ichtyosis and lamellar ichtyosis
  • anomalies in lipid packaging (location between stratum granulosum and stratum corneum)

• Gaucher and Niemann-Pick Diseases
  • anomalies in lipid processing (location in the stratum corneum)

Role of ceramides in the skin

• Structural roles:
  • constitute the backbone structure of sphingolipids
  • components of cell membranes
• epidermal permeability barrier function
• role in intracellular signaling
  • accumulation results in cell cycle arrest
  • regulation of cell differentiation
  • regulation of apoptosis/autophagy
• role in immunity
  • more precisely in innate immunity: induce antimicrobial peptide production

Contributors:

Dr Christophe HSU – dermatologist. Geneva, Switzerland

Source de l’Information. Uchida Y. The unique feature of epidermal barrier lipid formation. Investigative Dermatology (IID) 2013 – Edinburgh, United Kingdom (UK).