Abstract:

Objective To investigate the role of advanced glycation end products (AGEs) on expression of nicotinamide phosphoribosyltransferase (Nampt) in macrophages. Methods The macrophages were differentiated from human monocyte THP-1 by phorbol ester, and were treated with AGEs of 0 μg/mL (negative control group), 50 μg/mL, 100 μg/mL, 250 μg/mL, 500 μg/mL and 1000 μg/mL for 12 h, followed by detection of expression of Nampt protein by Western blotting. Microphages were treated with proper concentration of AGEs determined by Western blotting, cells were collected after treatment for 0 h(negative control group), 3 h, 6 h, 12 h and 24 h, and Real-Time PCR and Western blotting were employed to detect the expression of Nampt mRNA and protein in macrophages. Results After exposure to 50 μg/mL,100 μg/mL, 250 μg/mL and 500 μg/mL AGEs，the expression of Nampt protein in macrophages was significantly higher than that in negative control group (P＜0.01), and the expression of Nampt protein increased with the concentrations of AGEs, with that after exposure to 250 μg/mL and 500 μg/mL AGEs being higher. Macrophages in the following experiment was treated with 250 μg/mL AGEs. The expression of Nampt mRNA and protein in macrophages treated with 250 μg/mL AGEs was significantly higher than that in negative control group at each time point （P＜0.01）, and the expression of Nampt mRNA and protein increased with the time of exposure. Conclusion AGEs play a role in the increased expression of Nampt in macrophages, and AGEs may contribute to diabetic atherosclerosis by activating macrophages partly through Nampt pathway.

Key words: advanced glycation end products, macrophage, nicotinamide phosphoribosyltransferase