A Study on the Age-related Changes of Glycosaminoglycan in the Human Skin

Cha, Seung Hoon; Park, Seok Don

Abstract

BACKGROUND: The extracellular matrix constitutes the dermis supporting an overlying epidermal lining. A small portion of the cell component includes fibroblasts and mast cells, a large amount of fibrous tissue as struct ural proteins, intra-and extracellular adhesive molecules, and extracellular macromolecules, glyccsarninoglycan(GAG) and proteoglycan make up the dermal connective tissue. GAGs, polysacchavide chains secreted by fibroblasts, are the main macromolecules of the extracellular matrix. GAG chains occupy large amounts of extracellular space and form hydrated gels. The various manifestations observed during the cutaneous intrinsic aging process reflect the age-related changes of dermal connective tissue.
OBJECTIVE
This study was directed to observe the age-related changes of GAG in human abdominal skin without the influences of photoaeging.
MaTERIALS AND METHODS
The subjects involved in this study were grouped according to the age span of 10 years. A minimum of 3 skin samples were included in each age group. After permission, three to five grams of skin samples without known underlying skin diseases were obtained from the pat,ients who were subjected to open abdominal surgery under general anesthesia. GAGs were extracted and purified by repeated cetylpyridium chloride-ethanol precipitation from each skin sample. The qualitative and quantitative analysis of GAGs was carried out with the action of specific GAG degradirig enzymes.
RESULTS
The amount of GAGs per gram skin tissue decreased slowly until the 4th decade and thereafter. A statistically- significant reduction in the amount of GAGs was noted between the age groups of under 10 and that of 51-60. This pattern of decline was similar with tte change of the hyaluronic acid content in gram skin tissue. The content of chondroitin sulfate and heparan sulfate also decreased as a function of ageing. The compositional ratio of GAGs showed no age related changes. The water content measured by acetone dehydration was reduced to a significant level up to the age group of over 30 years.
CONCLUSION
These results imply that the wrinkling and laxity of skin during the chronological ageing process reflect the age-related reduction of GAGs and the water content of the skin.