Abstract
Neuronal death, which follows ischemic injury or is triggered by excitotoxins, can occur by both apoptosis and necrosis. Caspases, which are not directly required for necrotic cell death, are central mediators of the apoptotic program. Here we demonstrate that caspases cleave and inactivate the plasma membrane Ca(2+) pump (PMCA) in neurons and non-neuronal cells undergoing apoptosis. PMCA cleavage impairs intracellular Ca(2+) handling, which results in Ca(2+) overload. Expression of non-cleavable PMCA mutants prevents the disturbance in Ca(2+) handling, slows down the kinetics of apoptosis, and markedly delays secondary cell lysis (necrosis). These findings suggest that caspase-mediated cleavage and inactivation of PMCAs can lead to necrosis, an event that is reduced by caspase inhibitors in brain ischemia.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Animals, Newborn
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Apoptosis / drug effects
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Apoptosis / physiology*
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Binding Sites / drug effects
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Binding Sites / physiology
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CHO Cells
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Calcium / metabolism
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Calcium Signaling / drug effects
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Calcium Signaling / physiology
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Calcium-Transporting ATPases / drug effects
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Calcium-Transporting ATPases / metabolism*
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Caspase 3
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Caspases / drug effects
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Caspases / genetics
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Caspases / metabolism*
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Cation Transport Proteins
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Cell Membrane / drug effects
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Cell Membrane / enzymology*
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Clone Cells / cytology
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Clone Cells / drug effects
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Clone Cells / metabolism
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Coloring Agents
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Cricetinae
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Hypoxia-Ischemia, Brain / enzymology*
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Hypoxia-Ischemia, Brain / pathology
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Hypoxia-Ischemia, Brain / physiopathology
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Immunohistochemistry
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Intracellular Fluid / metabolism
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Mice
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Mutation / drug effects
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Mutation / genetics
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Necrosis*
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Neurons / drug effects
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Neurons / enzymology*
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Neurons / pathology
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Neurotoxins / pharmacology
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Plasma Membrane Calcium-Transporting ATPases
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Rats
Substances
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Cation Transport Proteins
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Coloring Agents
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Neurotoxins
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Casp3 protein, mouse
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Casp3 protein, rat
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Caspase 3
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Caspases
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Plasma Membrane Calcium-Transporting ATPases
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Calcium-Transporting ATPases
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Calcium