Novel macrophage receptor for glucose-modified proteins is distinct from previously described scavenger receptors.
A high-affinity macrophage receptor has been identified that recognizes proteins modified by a common in vivo process, long-term nonenzymatic reaction of glucose with proteins (AGE proteins). This receptor for glucose-modified proteins is now shown to be distinct from previously described scavenger receptors, using competition and crosscompetition experiments between AGE-modified protein and a variety of in vitro-modified scavenger receptor ligands, including unmodified BSA, unmodified low-density lipoproteins (LDL), acetyl-LDL, maleyl-BSA, and formaldehyde-treated BSA. Furthermore, the specific pattern of AGE-protein receptor inhibition by the polyanionic compounds polyinosinic acid, polyadenylic acid, polyglutamic acid, polycytidylic acid, fucoidin, and heparin was distinctly different from that of acetyl-LDL. By thus selectively recognizing a time-dependent in vivo protein modification, macrophages may preferentially degrade senescent macromolecules, thereby having an important role in the regulation of extracellular protein turnover.
D000375:Aging; D000818:Animals; D015815:Cell Adhesion Molecules; D005260:Female; D006031:Glycosylation; D008077:Lipoproteins, LDL / Q000378:metabolism; D008264:Macrophages / Q000032:analysis*; D051379:Mice; D019038:Platelet Glycoprotein GPIb-IX Complex; D010980:Platelet Membrane Glycoproteins; D011506:Proteins / Q000378:metabolism; D011971:Receptors, Immunologic / Q000032:analysis*; D011973:Receptors, LDL / Q000032:analysis; D051116:Receptors, Scavenger; D012710:Serum Albumin, Bovine / Q000378:metabolism
D015815:Cell Adhesion Molecules; D008077:Lipoproteins, LDL; D019038:Platelet Glycoprotein GPIb-IX Complex; D010980:Platelet Membrane Glycoproteins; D011506:Proteins; D011971:Receptors, Immunologic; D011973:Receptors, LDL; D051116:Receptors, Scavenger; C032629:acetyl-LDL; C032193:glycoprotein receptor GPIb-IX; D012710:Serum Albumin, Bovine