Inhibition of p27Kip1 expression by an anti-RAGE antibody. Fibroblast-like synovial cells (FLS) were incubated for 24 hours with either control-BSA (Co-BSA), advanced glycation end products-modified (AGE)-BSA or AGE-BSA together with the anti- receptor for AGEs (RAGE) antibody (a) The significant increase of p27Kip1 mRNA expression was inhibited when RAGE was blocked (AGE-BSA + anti-RAGE antibody versus AGE-BSA: P < 0.03, n = 5). (b) Western blot for p27Kip1 protein expression. The AGE-BSA-induced increase in p27Kip1 protein expression was abolished in the presence of the RAGE-blocking antibody (AGE-BSA + anti-RAGE antibody versus AGE-BSA: P < 0.05, n = 5). A representative western blot is shown underneath. GAPDH = glyceraldehyde 3-phosphate dehydrogenase.