title: Hyperglycemic Conditions Prime Cells for RIP1-dependent Necroptosis.
abstract: Necroptosis is a RIP1-dependent programmed cell death (PCD) pathway that is distinct from apoptosis. Downstream effector pathways of necroptosis include formation of advanced glycation end products (AGEs) and reactive oxygen species (ROS), both of which depend on glycolysis. This suggests that increased cellular glucose may prime necroptosis. Here we show that exposure to hyperglycemic levels of glucose enhances necroptosis in primary red blood cells (RBCs), Jurkat T cells, and U937 monocytes. Pharmacologic or siRNA inhibition of RIP1 prevented the enhanced death, confirming it as RIP1-dependent necroptosis. Hyperglycemic enhancement of necroptosis depends upon glycolysis with AGEs and ROS playing a role. Total levels of RIP1, RIP3, and mixed lineage kinase domain-like (MLKL) proteins were increased following treatment with high levels of glucose in Jurkat and U937 cells and was not due to transcriptional regulation. The observed increase in RIP1, RIP3, and MLKL protein levels suggests a potential positive feedback mechanism in nucleated cell types. Enhanced PCD due to hyperglycemia was specific to necroptosis as extrinsic apoptosis was inhibited by exposure to high levels of glucose. Hyperglycemia resulted in increased infarct size in a mouse model of brain hypoxia-ischemia injury. The increased infarct size was prevented by treatment with nec-1s, strongly suggesting that increased necroptosis accounts for exacerbation of this injury in conditions of hyperglycemia. This work reveals that hyperglycemia represents a condition in which cells are extraordinarily susceptible to necroptosis, that local glucose levels alter the balance of PCD pathways, and that clinically relevant outcomes may depend on glucose-mediated effects on PCD.
authors.affiliation: From the Department of Basic and Social Sciences, Albany College of Pharmacy and Health Sciences, Albany, New York 12208.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: LaRocca
authors.affiliation: the Department of Pediatrics, Columbia University, New York, New York 10032, and.
authors.forename: Sergey A
authors.initials: SA
authors.lastname: Sosunov
authors.affiliation: From the Department of Basic and Social Sciences, Albany College of Pharmacy and Health Sciences, Albany, New York 12208.
authors.forename: Nicole L
authors.initials: NL
authors.lastname: Shakerley
authors.affiliation: the Department of Pediatrics, Columbia University, New York, New York 10032, and.
authors.forename: Vadim S
authors.initials: VS
authors.lastname: Ten
authors.affiliation: the Department of Pediatrics, Columbia University, New York, New York 10032, and the Departments of Pediatrics and Microbiology, New York University, New York, New York 10016 Adam.Ratner@nyumc.org.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Ratner
mesh_terms: D000818:Animals; D016923:Cell Death; D004195:Disease Models, Animal; D004912:Erythrocytes / Q000378:metabolism* / Q000473:pathology; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism*; D017127:Glycation End Products, Advanced / Q000235:genetics / Q000378:metabolism; D006801:Humans; D006943:Hyperglycemia / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D019169:Jurkat Cells; D051379:Mice; D028861:Nuclear Pore Complex Proteins / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D020298:U937 Cells
chemical_list: C119724:AGFG1 protein, human; D020690:GTPase-Activating Proteins; D017127:Glycation End Products, Advanced; D028861:Nuclear Pore Complex Proteins; D016601:RNA-Binding Proteins; C490620:Ralbp1 protein, mouse
keywords: Fas ligand; apoptosis; diabetes; glucose; hyperglycemia; ischemia; necroptosis; necrosis (necrotic death); programmed cell death; tumor necrosis factor (TNF)