Extrinsic ageing in the human skin is associated with alterations in the expression of hyaluronic acid and its metabolizing enzymes

Exp Dermatol. 2009 Dec;18(12):1028-35. doi: 10.1111/j.1600-0625.2009.00889.x.


Extrinsic skin ageing or 'photoageing', as opposed to intrinsic skin ageing, is the result of exposure to external factors, mainly ultraviolet irradiation. Glycosaminoglycans (GAG) and particularly hyaluronic acid (HA) are major components of the cutaneous extracellular matrix involved in tissue repair. However, their involvement in extrinsic skin ageing remains elusive. In this study, we investigated the expression of HA and its metabolizing enzymes in photoexposed and photoprotected human skin tissue specimens, obtained from the same patient. Total GAG were isolated, characterized using specific GAG-degrading enzymes and separated by electrophoresis on cellulose acetate membranes and polyacrylamide gels. Quantitation of HA in total GAG was performed using ELISA. Gene expression of hyaluronan synthases (HAS), hyaluronidases (HYAL) and HA receptors CD44 and receptor for HA-mediated motility (RHAMM) was assessed by RT-PCR. We detected a significant increase in the expression of HA, of lower molecular mass, in photoexposed skin as compared with photoprotected skin. This increase was associated with a significant decrease in the expression of HAS1 and an increase in the expression of HYAL1-3. Furthermore, the expression of HA receptors CD44 and RHAMM was significantly downregulated in photoexposed as compared with photoprotected skin. These findings indicate that extrinsic skin ageing is characterized by distinct homoeostasis of HA. The elucidation of the role of HA homoeostasis in extrinsic skin ageing may offer an additional approach in handling cutaneous ageing.

MeSH terms

  • Aged
  • Cell Adhesion Molecules / genetics
  • Chondroitin Sulfates / metabolism
  • Dermatan Sulfate / metabolism
  • Down-Regulation / genetics
  • Extracellular Matrix Proteins / genetics
  • Female
  • GPI-Linked Proteins
  • Gene Expression / genetics
  • Gene Expression / radiation effects*
  • Glucuronosyltransferase / genetics*
  • Glycosaminoglycans / metabolism
  • Heparitin Sulfate / metabolism
  • Humans
  • Hyaluronan Receptors / genetics
  • Hyaluronan Synthases
  • Hyaluronic Acid / chemistry
  • Hyaluronic Acid / metabolism*
  • Hyaluronoglucosaminidase / genetics*
  • Male
  • Molecular Weight
  • Sex Characteristics
  • Skin / enzymology
  • Skin / metabolism*
  • Skin / radiation effects*
  • Skin Aging / physiology*
  • Ultraviolet Rays
  • Up-Regulation / genetics


  • CD44 protein, human
  • Cell Adhesion Molecules
  • Extracellular Matrix Proteins
  • GPI-Linked Proteins
  • Glycosaminoglycans
  • Hyaluronan Receptors
  • hyaluronan-mediated motility receptor
  • Dermatan Sulfate
  • Hyaluronic Acid
  • Chondroitin Sulfates
  • Heparitin Sulfate
  • Glucuronosyltransferase
  • HAS2 protein, human
  • HAS3 protein, human
  • Hyaluronan Synthases
  • Hyal2 protein, human
  • Hyaluronoglucosaminidase
  • hyaluronidase PH-20