The Potential Role of Non-Collagen Proteins in Skin Aging

• Cartilage oligomeric metric protein is part of the « non-collagen » proteins of the extracellular matrix and interacts with collagen I via fibril associated fibrils XII and XIV
  • was previously only found in cartilage
  • In fibrotic skin such as in localized scleroderma (morphea) wound tissue and exudates of patients with venous ulcers and in the stroma of basal cell carcinoma lesions, COMP levels have been shown to be increased

• comparison in mice of early post natal and adult skin of mice deficient in COMP versus normal (wild type) controls.
  • In controls deposits in the seen added up for 4-18 days after birth and then declined
  • The appearance of the skin was tested hand thinning of the dermis was seen in COMP deficient mice.
  • At 6 weeks although the dermis was not reduced, there were significant alterations regarding the mechanical properties and the ultrastructure of the dermal collagen matrix
  • Electron microscopy in COMP deficient mice revealed dilated cistern in the endoplasmic reticulum of the fibroblasts suggesting protein retention (of collagen XII ). Collagen fibrils were tightly packed and shaped highly irregularly.
  • COMP deficiency also results in dermal thinning and tilted hair follicles

COMP supports the assembly of collagen I and XII fibrils in the ER and facilitate their secretion from fibroblasts

Comment: this study reminds us that many molecules participate in the functioning of skin, and that beyond collagen and hyaluronic acid, those cannot be ignored.

Contributors

Dr Christophe Hsu – dermatologist. Geneva, Switzerland

Source of information: P03-08. Hayashi S et al. Cartilage oligomeric metric protein (COMP) has the important role for the collagen network architecture and elasticity of the skin. JSID Annual Meeting (Japanese Society of Investigative Dermatology, 日本研究皮膚科学会) 2014 – Osaka, Japan