title: Oxidation and erythrocyte senescence.
abstract: Direct macrophage recognition of an externalized phosphatidylserine signal on senescent erythrocytes is a process of erythrophagocytic clearance that is in line with the general clearance process of all other circulating cells that become apoptotic. Advances in deciphering this process suggest that oxidation of the erythrocyte's hemoglobin, the salient target of the free radicals encountered in the circulatory environment, may drive subsequent steps. The progressive accumulation of oxidized hemoglobin covalently bound to the membrane skeleton not only disrupts membrane organization but also threatens eventual phospholipid oxidation via a calcium-promoted quasi-lipoxygenase activity. The emergence on the cell surface of a threshold concentration of oxidized phospholipids, principally phosphatidylserine, signals recognition by the CD36 macrophage receptor.
authors.affiliation: Department of Hospital Laboratories/Clinical Pathology, UMASS Memorial Medical Center, Worcester, Massachusetts 01605, USA.
authors.forename: C R
authors.initials: CR
authors.lastname: Kiefer
authors.forename: L M
authors.initials: LM
authors.lastname: Snyder
mesh_terms: D000818:Animals; D018955:CD36 Antigens / Q000378:metabolism; D004905:Erythrocyte Aging / Q000502:physiology*; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008264:Macrophages / Q000276:immunology / Q000378:metabolism; D010084:Oxidation-Reduction; D010718:Phosphatidylserines / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D018955:CD36 Antigens; D006454:Hemoglobins; D010718:Phosphatidylserines