title: Extrinsic ageing in the human skin is associated with alterations in the expression of hyaluronic acid and its metabolizing enzymes.
abstract: 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.
authors: 2nd Department of Pharmacology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors: T G
authors: TG
authors: Tzellos
authors: I
authors: I
authors: Klagas
authors: K
authors: K
authors: Vahtsevanos
authors: S
authors: S
authors: Triaridis
authors: A
authors: A
authors: Printza
authors: A
authors: A
authors: Kyrgidis
authors: G
authors: G
authors: Karakiulakis
authors: C C
authors: CC
authors: Zouboulis
authors: E
authors: E
authors: Papakonstantinou
mesh_terms: D000368:Aged; D015815:Cell Adhesion Molecules / Q000235:genetics; D002809:Chondroitin Sulfates / Q000378:metabolism; D003871:Dermatan Sulfate / Q000378:metabolism; D015536:Down-Regulation / Q000235:genetics; D016326:Extracellular Matrix Proteins / Q000235:genetics; D005260:Female; D058851:GPI-Linked Proteins; D015870:Gene Expression / Q000235:genetics / Q000528:radiation effects*; D014453:Glucuronosyltransferase / Q000235:genetics*; D006025:Glycosaminoglycans / Q000378:metabolism; D006497:Heparan Sulfate / Q000378:metabolism; D006801:Humans; D018960:Hyaluronan Receptors / Q000235:genetics; D000076002:Hyaluronan Synthases; D006820:Hyaluronic Acid / Q000737:chemistry / Q000378:metabolism*; D006821:Hyaluronoglucosaminidase / Q000235:genetics*; D008297:Male; D008970:Molecular Weight; D012727:Sex Characteristics; D012867:Skin / Q000201:enzymology / Q000378:metabolism* / Q000528:radiation effects*; D015595:Skin Aging / Q000502:physiology*; D014466:Ultraviolet Rays; D015854:Up-Regulation / Q000235:genetics
chemical_list: D015815:Cell Adhesion Molecules; D002809:Chondroitin Sulfates; D003871:Dermatan Sulfate; D016326:Extracellular Matrix Proteins; D058851:GPI-Linked Proteins; D014453:Glucuronosyltransferase; D006025:Glycosaminoglycans; D006497:Heparan Sulfate; D018960:Hyaluronan Receptors; D000076002:Hyaluronan Synthases; D006820:Hyaluronic Acid; D006821:Hyaluronoglucosaminidase; C497483:CD44 protein, human; C098946:hyaluronan-mediated motility receptor; C101754:HAS2 protein, human; C105458:HAS3 protein, human; C473096:Hyal2 protein, human; C066852:hyaluronidase PH-20