NONENZYMATIC GLYCATION OF FIBRONECTIN IMPAIRS ADHESIVE AND PROLIFERATIVE PROPERTIES OF HUMAN VASCULAR SMOOTH-MUSCLE CELLS

Nonenzymatic glycation of proteins is involved in the pathogenesis of diabetes vascular complications. Extracellular matrix proteins are a p rominent target for nonenzymatic glycation because of their slow turno ver rates. The aim of this study was to investigate the influence of h uman fibronectin (F) nonenzymatic glycation on adhesion and proliferat ion of cultured human vascular smooth muscle cells (hVSMC). Incubation of human F with 500 mmol/L D-glucose at 37 degrees C induced a time-d ependent increase in fluorescence detectable at 440 nm after excitatio n at 363 nm. Nonenzymatic glycation did not affect binding of F itself to the plates. Adhesion of hVSMC to F increased with the increase of incubation time of the cells on the protein from 30 minutes up to 120 minutes and remained stable thereafter. Adhesion to glycated fibronect in (GF) was reduced in comparison to control F at all the different ad hesion times. Adhesion of hVSMC to GF was reduced when F was exposed t o glucose for 4, 9, or 28 days (P = .0417 to .0025), but not when F wa s exposed to glucose for 1 day. Adhesion of hVSMC to GF was reduced co mpared with adhesion to nonglycated F at all coating concentrations fr om 0.2 to 10 mu g/mL (P = .05 to .014). Thus, nonenzymatic glycation o f F impairs adhesion of hVSMC in vitro. Proliferation of hVSMC on F in creased with increasing concentrations of the protein as coating agent (ANOVA: P < .0001 for both nonglycated F and GF). Proliferation with F glycated for 4, 9, and 28 days was reduced at concentrations of 1, 3 , and 10 mu g/mL as compared with proliferation with nonglycated F (P = .0253 to .0001). Proliferation on F glycated for only 1 day was not significantly reduced. When the number of hVSMC plated on control F wa s reduced by 25% to take into account the reduced adhesion, the number of cells that proliferated on F was still reduced. In conclusion, non enzymatic glycation of F impairs adhesive and proliferative properties of hVSMC. Copyright (C) 1996 by W.B. Saunders Company