title: Calpain facilitates the neuron death induced by 3-nitropropionic acid and contributes to the necrotic morphology.
abstract: 3-Nitropropionic acid (3NP), an irreversible inhibitor of succinate dehydrogenase, has been used to model features of neurodegenerative disorders including Huntington disease, as well as acute neuronal insults such as cerebral ischemia. 3NP induces rapid necrosis and delayed apoptosis in primary cultures of rat hippocampal neurons. Low levels of extracellular glutamate shift the cell death mechanism to necrosis, whereas antagonism of NMDA receptors results in predominately apoptotic death. In the present study, the involvement of cysteine proteases in the morphologic and biochemical alterations accompanying 3NP-induced neuron death was investigated. Immunoblots of spectrin breakdown products indicated Ca(2+)-dependent cysteine protease (calpain) activation within the 8 hours of 3NP administration, whereas caspase-3 activation was not evident until 16 to 48 hours after treatment. The NMDA receptor antagonist MK-801 (dizocilpine) decreased 3NP-induced calpain activity, but did not alter caspase-3 activity. Similar to MK-801, calpain inhibitors (Z-Val-Phe.H and Z-Leu-Phe-CONHEt) shifted the cell death morphology towards apoptosis and delayed, but did not prevent, the 3NP-induced cell death. Together, the results indicate that following 3NP administration, increased calpain activity precedes caspase-3 activation, contributes to the necrotic morphology, and facilitates and accelerates the cell death.
authors.affiliation: Sanders-Brown Center on Aging and Department of Anatomy and Neurobiology, University of Kentucky, Lexington, Kentucky, KY 40536-0230, USA.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Pang
authors.forename: Vimala
authors.initials: V
authors.lastname: Bondada
authors.forename: Tomoko
authors.initials: T
authors.lastname: Sengoku
authors.forename: Robert
authors.initials: R
authors.lastname: Siman
authors.forename: James W
authors.initials: JW
authors.lastname: Geddes
mesh_terms: D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000502:physiology; D002154:Calpain / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D020169:Caspases / Q000378:metabolism; D016923:Cell Death; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D015853:Cysteine Proteinase Inhibitors; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004357:Drug Synergism; D004622:Embryo, Mammalian; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D015151:Immunoblotting / Q000379:methods; D007150:Immunohistochemistry / Q000379:methods; D009336:Necrosis; D009474:Neurons / Q000187:drug effects* / Q000473:pathology; D009498:Neurotoxins / Q000633:toxicity*; D009574:Nitro Compounds; D009842:Oligopeptides / Q000494:pharmacology; D011422:Propionates / Q000633:toxicity*; D051381:Rats; D013049:Spectrin / Q000378:metabolism; D013997:Time Factors
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D015853:Cysteine Proteinase Inhibitors; D018691:Excitatory Amino Acid Antagonists; D009498:Neurotoxins; D009574:Nitro Compounds; D009842:Oligopeptides; D011422:Propionates; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C104205:z-VAD-DCB; D013049:Spectrin; D018698:Glutamic Acid; D016291:Dizocilpine Maleate; D002154:Calpain; D020169:Caspases; C015392:3-nitropropionic acid