The catalytic subunit of telomerase protects neurons against amyloid beta-peptide-induced apoptosis.
The catalytic subunit of telomerase (TERT) is a specialized reverse transcriptase that has been associated with cell immortalization and cancer. It was reported recently that TERT is expressed in neurons throughout the brain in embryonic and early postnatal development, but is absent from neurons in the adult brain. We now report that suppression of TERT levels and function in embryonic mouse hippocampal neurons in culture using antisense technology and the telomerase inhibitor 3' -azido-2' 3' -dideoxythymidine significantly increases their vulnerability to cell death induced by amyloid beta-peptide, a neurotoxic protein believed to promote neuronal degeneration in Alzheimer's disease. Neurons in which TERT levels were reduced exhibited increased levels of oxidative stress and mitochondrial dysfunction following exposure to amyloid beta-peptide. Overexpression of TERT in pheochromocytoma cells resulted in decreased vulnerability to amyloid beta-peptide-induced apoptosis. Our findings demonstrate a neuroprotective function of TERT in an experimental model relevant to Alzheimer's disease, and suggest the possibility that restoration of TERT expression in neurons in the adult brain may protect against age-related neurodegeneration.
Zhu
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Sanders-Brown Research Center on Aging, University of Kentucky, Lexington, Kentucky. Laboratory of Neurosciences, National Institute on Aging, Baltimore, Maryland, USA.
Fu
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Mattson
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MP
D000544:Alzheimer Disease; D016229:Amyloid beta-Peptides / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D020134:Catalytic Domain; D002478:Cells, Cultured; D004268:DNA-Binding Proteins; D004622:Embryo, Mammalian; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015870:Gene Expression; D006624:Hippocampus; D007150:Immunohistochemistry; D051379:Mice; D008928:Mitochondria / Q000502:physiology; D009474:Neurons / Q000166:cytology* / Q000201:enzymology; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D018384:Oxidative Stress; D016716:PC12 Cells; D012313:RNA; D051381:Rats; D019098:Telomerase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000502:physiology*
D016229:Amyloid beta-Peptides; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D016376:Oligonucleotides, Antisense; C422952:telomerase RNA; D012313:RNA; D019098:Telomerase; C509187:Tert protein, mouse