Effects of advanced glycation end products on the proliferation and fibronectin production of smooth muscle cells.
The aim of this study was to evaluate the effects of advanced glycation end-products (AGEs) on the proliferative activity and fibronectin production of smooth muscle cells (SMCs). AGE-bovine serum albumin (AGE-BSA) was prepared by incubation with D-glucose at 37 degrees C for 60 days. Cultured SMCs were obtained from explants isolated from porcine abdominal aorta and used between passages 3 and 10. The proliferative activity of SMCs was examined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay and by incorporation of 3H-thymidine into DNA. Fibronectin production was assessed by competitive ELISA assay for both fibronectin secreted into the culture medium (M-FN) and cell-associated fibronectin (C-FN), i.e., both intra- and peri-cellular fibronectin. Theassay revealed that AGE-BSA did not produce any change in optical density (A570) of SMCs at concentrations of up to 20 microg/ml, but decreased that of SMCs at a concentration of 40 microg/ml. The addition of PDGF (5 ng/ml) induced an increase in 3H-thymidine incorporation into DNA of quiescent SMCs, while the addition of AGE-BSA (20 microg/ml) had no effect. In contrast, AGE-BSA significantly increased C-FN of SMCs (30.8+/-8.58 ng/microg TP), compared to unmodified BSA (16.5+/-4.19 ng/microg TP). However, no difference in M-FN levels was observed between cells treated with AGE-BSA and unmodified BSA. The addition of anti-transforming growth factor (TGF)-beta antibody restored the levels of C-FN in SMCs cultured in 20 microg/ml of AGE-BSA, suggesting that TGF-beta might act as an intermediate factor in AGE-induced fibronectin production by SMCs. Our results suggest that interaction of AGE-modified proteins with SMCs may play a role in the development of atherosclerosis in diabetic and non-diabetic patients.
Sakata
N
N
Second Department of Pathology, School of Medicine, Fukuoka University, Japan. nysakata@fukuoka-u.ac.jp
Meng
J
J
Takebayashi
S
S
D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D005353:Fibronectins / Q000096:biosynthesis*; D017127:Glycation End Products, Advanced / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D013552:Swine; D013778:Tetrazolium Salts; D013844:Thiazoles; D013936:Thymidine / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000037:antagonists & inhibitors
D000906:Antibodies; D005353:Fibronectins; D017127:Glycation End Products, Advanced; D013778:Tetrazolium Salts; D013844:Thiazoles; D016212:Transforming Growth Factor beta; C081628:advanced glycation end products-bovine serum albumin; D012710:Serum Albumin, Bovine; C022616:thiazolyl blue; D013936:Thymidine