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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2009-2-3
pubmed:abstractText
Importins, also called karyopherins, belong to a large family of proteins involved in cytoplasm-to-nucleus transport. Transport machinery generally involves a complex formed by two different importin subtypes (alpha and beta). Both alpha and beta importins are expressed in the brain, and their expression and localization is regulated by physiological neuronal activity. Little is known about regulation of importin expression in brain pathological conditions. Here we studied the expression of importin beta1 (imp beta 1) in the rat hippocampus after acute and chronic seizures induced by the glutamate agonist kainic acid (KA). The overall content of imp beta 1 mRNA and protein did not change after acute KA seizures. However, acute KA seizures rapidly induced the translocation of imp beta 1 protein from the cytoplasm to the nucleus in pyramidal CA1 neurons. KA-induced imp beta 1 translocation was prevented by the NMDA (N-methyl-D-aspartic acid) receptor blocker MK-801. After chronic seizures, the overall levels of imp beta 1 mRNA and protein did not change in the whole hippocampus. Immunohistochemistry revealed a massive loss of imp beta 1-positive neurons in pyramidal layers (that degenerated after KA), whereas an increased number of imp beta 1-positive cells was detected in the stratum radiatum of rats with chronic seizures compared with control animals. Double-labeling experiments identified these cells as glial cells expressing the chondroitin sulfate proteoglycan NG2 (neuron/glial antigen 2), a glial subtype recently shown to regulate hippocampal neuron excitability. These data show a differential regulation of imp beta 1 expression after acute and chronic seizure activity in the rat hippocampus.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1097-4547
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
87
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
636-43
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Seizures increase importin-beta1 expression in NG2+ cells in the rat hippocampus.
pubmed:affiliation
Institute of Neurosciences, CNR, Pisa, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't