Cell-associated pentosidine as a marker of aging in human diploid cells invitro and in vivo

Cellular aging is characterized by alterations at both the morphological an d molecular levels, some of which are decreased mitotic rate, increased cyt oplasmic vacuolization, and changes in intrinsic cellular constituents (Sta nulis-Praeger, 1987. Mech. Ageing Dev. 38, 1-48). In the present investigat ion, glycoxidation is studied as a marker for cellular aging by measuring c ell-associated pentosidine levels in human skin fibroblasts as a function o f replicative life span and in human peripheral blood T lymphocytes as a fu nction of chronological age. Fibroblasts were isolated from culture by deta chment/centrifugation while lymphocytes were isolated from blood by a Ficol l-Paque/Lympho-Kwik T-Cell Prep technique. Pentosidine levels were measured in acid-hydrolyzed cell pellet suspensions by high-pressure liquid chromat ography. Results show that pentosidine was detected in early and late cultu red reticular and papillary fibroblasts. Pentosidine, expressed as either p rotein, DNA, or cell number, significantly (P < 0.0006) increased with in v itro passage and was significantly (P < 0.01) related to cell proliferation as measured by cell density and cell doublings per day during culture. Cel l-associated pentosidine was measured in T lymphocytes isolated from health y, diabetic, and uremic individuals. In healthy controls, levels significan tly (P < 0.0003) increased with age. In uremic individuals, a large variati on was observed with many values above the 95% confidence intervals determi ned for controls. Since a previous study showed that plasma pentosidine in healthy subjects does not increase with age, these results suggest that cel lular turnover perhaps coupled to a deterioration in cellular anti-glycoxid ation defensive mechanisms play a substantial role in explaining increased pentosidine concentrations during cellular aging. (C) 1998 Elsevier Science Ltd. All rights reserved.