TRAIL death receptors DR4 and DR5 mediate cerebral microvascular endothelial cell apoptosis induced by oligomeric Alzheimer's Aβ.
Vascular deposition of amyloid-β (Aβ) in sporadic and familial Alzheimer's disease, through poorly understood molecular mechanisms, leads to focal ischemia, alterations in cerebral blood flow, and cerebral micro-/macro-hemorrhages, significantly contributing to cognitive impairment. Here, we show that tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) death receptors DR4 and DR5 specifically mediate oligomeric Aβ induction of extrinsic apoptotic pathways in human microvascular cerebral endothelial cells with activation of both caspase-8 and caspase-9. The caspase-8 inhibitor cellular FLICE-like inhibitory protein (cFLIP) is downregulated, and mitochondrial paths are engaged through BH3-interacting domain death agonist (Bid) cleavage. Upregulation of DR4 and DR5 and colocalization with Aβ at the cell membrane suggests their involvement as initiators of the apoptotic machinery. Direct binding assays using receptor chimeras confirm the specific interaction of oligomeric Aβ with DR4 and DR5 whereas apoptosis protection achieved through RNA silencing of both receptors highlights their active role in downstream apoptotic pathways unveiling new targets for therapeutic intervention.
Department of Pathology, New York University School of Medicine, New York, NY 10016, USA.
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Fossati
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Ghiso
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Rostagno
D000544:Alzheimer Disease / Q000378:metabolism* / Q000473:pathology; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D017209:Apoptosis; D051023:BH3 Interacting Domain Death Agonist Protein / Q000378:metabolism; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein / Q000378:metabolism; D053181:Caspase 8 / Q000378:metabolism; D020169:Caspases / Q000378:metabolism; D042783:Endothelial Cells / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D034622:RNA Interference; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000235:genetics / Q000378:metabolism*; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation
D016229:Amyloid beta-Peptides; D051023:BH3 Interacting Domain Death Agonist Protein; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor; C105190:TNFRSF10A protein, human; C114109:TNFRSF21 protein, human; C513669:caspase 9s, human; C505530:CASP8 protein, human; D053181:Caspase 8; D020169:Caspases