Histone functions as a cell-surface receptor for AGEs

Reducing sugars can covalently react with proteins to generate a heterogeneous and complex group of compounds called advanced glycation end products (AGEs). AGEs are generally considered as pathogenic molecules, mediating a pro-inflammatory response and contributing to the development of a number of human diseases. However, the intrinsic function of AGEs remains to be elucidated. We now provide multiple lines of evidence showing that AGEs can specifically bind a cell-surface protein and regulate its functions. To identify cellular binding partners for AGEs, we used dehydroascorbic acid (DHA)-modified serum albumins as one of the AGEs to screen for binding proteins in the lipid raft fraction prepared from mouse splenocytes and identified histone localized on the cell-surface as an AGE-binding protein. Histone ubiquitously recognized AGEs, including proteins modified with glucose and its metabolites. AGEs inhibited the binding of plasminogen to the histone component H2B which functions as a cell-surface plasminogen receptor on monocytes/macrophages. Moreover, AGEs regulated the recruitment of monocytes/macrophage to the site of inflammation. Our discovery of histone as a cell-surface receptor for AGEs suggests that, beside our common concept of AGEs as danger-associated molecular patterns mediating a pro-inflammatory response, they may also be involved in the homeostatic response via binding to histone. We evaluated transcripts in peritoneal macrophages derived from mice treated with BSA or AGEs by RNA-seq.