MODIFICATIONS OF PROTEOGLYCANS EXTRACTED FROM MONOLAYER-CULTURES OF YOUNG AND SENESCENT HUMAN SKIN FIBROBLASTS

Proteoglycans (PGs) were extracted from culture monolayers of human sk in fibroblasts (HFs) at early and late passages, Total PGs from senesc ent cells had markedly reduced abilities to bind type I collagen and h yaluronic acid, but retained normal binding properties with fibronecti n and laminin, The constituent polysaccharides of PGs mere comparative ly characterised, PGs recovered from young and senescent HF cultures h ad equivalent total polyanionic charges and similar size distributions of the glycosaminoglycan chains, This applied to both types of polysa ccharide chains found in PGs, namely the galactosaminoglycuronans (Gal N-GAGs) and the glucosaminoglycuronans (GlcN-GAGs), However, senescent HFs produced a greater proportion of PGs containing GlcN-GAG chains a nd increased the sulphation of the remainding PG fraction with GalN-GA G moieties, yielding a major gain of CB-sulphate groups in the galacto samine residues. (C) 1997 Federation of European Biochemical Societies .