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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2008-8-7
pubmed:abstractText
Previously, we reported that apoptosis of cerebellar granular neurons induced by low-K+ and serum-free (LK-S) was associated with an increase in the A-type K+ channel current (I(A)), and an elevated expression of main alpha-subunit of the I(A) channel, which is known as Kv4.2 and Kv4.3. Here, we show, as assessed by quantitative RT-PCR and whole-cell recording, that besides Kv4.2 and Kv4.3, Kv1.1 is very important for I(A) channel. The expression of Kv1.1 was elevated in the apoptotic neurons, while silencing Kv1.1 expression by siRNA reduced the I(A) amplitude of the apoptotic neuron, and increased neuron viability. Inhibiting Kv1.1 current by dendrotoxin-K evoked a similar effect of reduction of I(A) amplitude and protection of neurons. Applying a protein kinase C (PKC) activator, phorbol ester acetate A (PMA) mimicked the LK-S-induced neuronal apoptotic effect, enhanced the I(A) amplitude and reduced the granule cell viability. The PKC inhibitor, bisindolylmaleimide I and Gö6976 protected the cell against apoptosis induced by LK-S. After silencing the Kv1.1 gene, the effect of PMA on the residual K+ current was reduced significantly. Quantitative RT-PCR and Western immunoblot techniques revealed that LK-S treatment and PMA increased the level of the expression of Kv1.1, in contrast, bisindolylmaleimide I inhibited Kv1.1 expression. In addition, the activation of the PKC isoform was identified in apoptotic neurons. We thus conclude that in the rat cerebellar granule cell, the I(A) channel associated with apoptotic neurons is encoded mainly by the Kv1.1 gene, and that the PKC pathway promotes neuronal apoptosis by a brief modulation of the I(A) amplitude and a permanent increase in the levels of expression of the Kv1.1 alpha-subunit.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1471-4159
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
106
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1125-37
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Kv 1.1 is associated with neuronal apoptosis and modulated by protein kinase C in the rat cerebellar granule cell.
pubmed:affiliation
The Institute of Brain Science, School of Life Sciences and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't