Glycolaldehyde-derived advanced glycation end products promote macrophage proliferation via the JAK-STAT signaling pathway.

ABSTRACT

BACKGROUND: Advanced glycation end products (AGEs) are heterogeneous proinflammatory molecules produced by a non-enzymatic glycation reaction between reducing sugars (and their metabolites) and biomolecules with amino groups, such as proteins. Although increases in and the accumulation of AGEs have been implicated in the onset and exacerbation of lifestyle- or age-related diseases, including diabetes, their physiological functions have not yet been elucidated in detail. METHODS AND RESULTS: The present study investigated the cellular responses of the macrophage cell line RAW264.7 stimulated by glycolaldehyde-derived AGEs (Glycol-AGEs) known as representative toxic AGEs. The results obtained showed that Glycol-AGEs significantly promoted the proliferation of RAW264.7 cells at a low concentration range (1-10 µg/mL) in a concentration-dependent manner. On the other hand, neither TNF-α production nor cytotoxicity were induced by the same concentrations of Glycol-AGEs. The increases observed in cell proliferation by low concentrations of Glycol-AGEs were also detected in receptor triple knockout (RAGE-TLR4-TLR2 KO) cells as well as in wild-type cells. Increases in cell proliferation were not affected by various kinase inhibitors, including MAP kinase inhibitors, but were significantly suppressed by JAK2 and STAT5 inhibitors. In addition, the expression of some cell cycle-related genes was up-regulated by the stimulation with Glycol-AGEs. CONCLUSIONS: These results suggest a novel physiological role for AGEs in the promotion of cell proliferation via the JAK-STAT pathway.