title: Reduced expression of plasma membrane calcium ATPase 2 and collapsin response mediator protein 1 promotes death of spinal cord neurons.
abstract: The mechanisms underlying neuronal pathology and death in the spinal cord (SC) during inflammation remain elusive. We previously showed the important role of plasma membrane calcium ATPases (PMCAs) in the survival of SC neurons, in vitro. We also postulated that a decrease in PMCA2 expression could cause neuronal death during experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. The current studies were undertaken to define the specific contribution of PMCA2 to degeneration of SC neurons, the effectors downstream to PMCA2 mediating neuronal death and the triggers that reduce PMCA2 expression. We report that knockdown of PMCA2 in SC neurons decreases collapsin response mediator protein 1 (CRMP1) levels. This is followed by cell death. Silencing of CRMP1 expression also leads to neuronal loss. Kainic acid reduces both PMCA2 and CRMP1 levels and induces neuronal death. Administration of an alpha-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA)/kainate receptor antagonist, at onset or peak of EAE, restores the decreased PMCA2 and CRMP1 levels to control values and ameliorates clinical deficits. Thus, our data link the reduction in PMCA2 expression with perturbations in the expression of CRMP1 and the ensuing death of SC neurons. This represents an additional mechanism underlying AMPA/kainate receptor-mediated excitotoxicity with relevance to neurodegeneration in EAE.
authors.affiliation: Department of Neurology and Neuroscience, New Jersey Medical School-UMDNJ, Newark, 07103, USA.
authors.forename: M P
authors.initials: MP
authors.lastname: Kurnellas
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.forename: M R
authors.initials: MR
authors.lastname: Jain
authors.forename: S N
authors.initials: SN
authors.lastname: Giraud
authors.forename: A B
authors.initials: AB
authors.lastname: Nicot
authors.forename: A
authors.initials: A
authors.lastname: Ratnayake
authors.forename: R F
authors.initials: RF
authors.lastname: Heary
authors.forename: S
authors.initials: S
authors.lastname: Elkabes
mesh_terms: D000818:Animals; D002135:Calcium-Binding Proteins / Q000494:pharmacology; D002154:Calpain / Q000037:antagonists & inhibitors / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects / Q000502:physiology*; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D002478:Cells, Cultured; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004622:Embryo, Mammalian / Q000166:cytology; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000188:drug therapy / Q000378:metabolism / Q000517:prevention & control; D015870:Gene Expression / Q000187:drug effects / Q000235:genetics; D007608:Kainic Acid / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D053499:Plasma Membrane Calcium-Transporting ATPases / Q000235:genetics / Q000378:metabolism*; D020543:Proteome / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D011810:Quinoxalines / Q000494:pharmacology / Q000627:therapeutic use; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D011919:Rats, Inbred Strains; D018091:Receptors, AMPA / Q000819:agonists / Q000037:antagonists & inhibitors; D018092:Kainic Acid Receptors / Q000819:agonists / Q000037:antagonists & inhibitors; D013116:Spinal Cord / Q000166:cytology*; D000098855:Collapsin Response Mediator Protein 1
chemical_list: D002135:Calcium-Binding Proteins; D002154:Calpain; D015853:Cysteine Proteinase Inhibitors; D007608:Kainic Acid; D009419:Nerve Tissue Proteins; D010750:Phosphoproteins; D053499:Plasma Membrane Calcium-Transporting ATPases; D020543:Proteome; D011810:Quinoxalines; D034741:RNA, Small Interfering; D018091:Receptors, AMPA; D018092:Kainic Acid Receptors; D000098855:Collapsin Response Mediator Protein 1; C506961:Atp2b2 protein, rat; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; C033668:calpastatin; C506959:Atp2b2 protein, mouse