2012 Fiscal Year Final Research Report
The improved effect of hypothermic cultivation on thefunctional expression of human cardiac Kv1.5 channels
| Project/Area Number |
22590206
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General physiology
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| Research Institution | Shiga University of Medical Science |
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Principal Investigator |
DING Weiguang 滋賀医科大学, 医学部, 助教 (80242973)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUURA Hiroshi 滋賀医科大学, 医学部, 教授 (60238962)
OMATSU-KANBE Mariko 滋賀医科大学, 医学部, 教授 (80161397)
TOYODA Futoshi 滋賀医科大学, 医学部, 助教 (90324574)
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| Project Period (FY) |
2010 – 2012
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| Keywords | Kv1.5 / 細胞内輸送 / 低温培養 / 心筋 / 心房細動 |
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| Research Abstract |
We herein investigated the effect of low temperature exposure in the channel activity, expression, degradation and localization of human Kv1.5 (hKv1.5). In hKv1.5-expressing CHO cells, the currents significantly increased at a reduced temperature cultivation (28℃) in comparison to those observed at 37℃. A Western blot analysis confirmed that the protein levels (immature and mature proteins) of hKv1.5 were significantly elevated under hypothermic conditions. The treatment with a proteasome inhibitor, MG132, significantly increased the immature (but not the mature) hKv1.5 protein at 37℃; there were no changes in either the immature or mature hKv1.5 proteins at low temperature conditions after MG132 exposure, thus indicating that the enhancement of the mature hKv1.5 protein at reduced temperature may not result from the inhibition of proteolysis. Moreover, the hKv1.5 fluorescence signal in the HEK cells increased significantly on the cell surface at 28℃ versus those cultured at 37℃. Importantly, the low temperature treatment markedly shifted the subcellular distribution of the mature hKv1.5 lighter fractions, which showed considerable overlap with the trans-Golgi component. Finally, the hypothermic treatment also rescued the protein expression and functional currents of trafficking-defective hKv1.5 mutants (I502A, I508A, located in the pore region). These results indicate that low temperature exposure stabilizes the protein in the cellular organs, modulates its recycling trafficking, thus enhancing functional hKv1.5 currents.
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[Journal Article] (2012) Phenotype variability in patients carrying KCNJ2 mutations.2012
Author(s)
Kimura H, Zhou J, Kawamura M, Itoh H, Mizusawa Y, Ding WG, Wu J, Ohno S, Makiyama T, Miyamoto A, Naiki N, Wang Q, Xie Y, Suzuki T, Tateno S, Nakamura Y, Zang WJ, Ito M, Matsuura H, Horie M.
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Journal Title
Circ Cardiovasc Genet
Volume: 5(3)
Pages: 344-53
Peer Reviewed
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[Journal Article] (2011) KCNE5 (KCNE1L) variants are novel modulators of Brugada syndrome and idiopathic ventricular fibrillation.2011
Author(s)
Ohno S, Zankov DP, Ding WG, Itoh H, Makiyama T, Doi T, Shizuta S, Hattori T, Miyamoto A, Naiki N, Hancox JC, Matsuura H, Horie M.
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Journal Title
Circ Arrhythm Electrophysiol
Volume: 4(3)
Pages: 352-61
Peer Reviewed
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[Journal Article] (2010) Atrioventricular block-induced Torsades de Pointes with clinical and molecular backgrounds similar to congenital long QT syndrome2010
Author(s)
Oka Y, Itoh H, Ding WG, Shimizu W, Makiyama T, Ohno S, Nishio Y, Sakaguchi T, Miyamoto A, Kawamura M, Matsuura H, Horie M
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Journal Title
Circ J.25
Volume: 74
Pages: 2562-71
Peer Reviewed
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[Journal Article] KCNE2 modulation of Kv4.3 current and its role in inherited fatal rhythm disorders2010
Author(s)
Wu J, Shimizu W, Ding WG, Ohno S, Toyada F, Itoh H, Zang WJ, Miyamoto Y, Kamakura S, Matsuura H, Nademanee K, Brugada J, Brugada P, Brugada R, Vatta M, Towbin JA, Antzelevitch C, Horie M
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Journal Title
Heart Rhythm
Volume: 7
Pages: 199-205
Peer Reviewed
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