2007 Fiscal Year Final Research Report Summary
Establishment of molecular targeting therapy for duonic heart failure bystabilizmgryanodine receptor
| Project/Area Number |
18390234
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Circulatory organs internal medicine
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| Research Institution | Yamaguchi University |
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Principal Investigator |
YANO Masafumi Yamaguchi University, Hospital, Associate Professor (90294628)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAMOTO Takeshi Yamaguchi University, Graduate School of Medicine, Assistant Professor (50363122)
IKEDA Yasuhiro Yamaguchi University, School of Medicine, Associate Professor (00260349)
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| Project Period (FY) |
2006 – 2007
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| Keywords | sarcoplasmic reticulum / scalcium / rvanodine receptor / heart failure / lethal arrhythmia / point mutation |
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| Research Abstract |
Two domains within the ryanodine receptor (RyR2) of sarcoplasmic reticulum (SR) {N-terminal (0-600) and central (2000-2500) domains} was found to interact with each other as a regulatory switch for channel gating. We previously reported that K201 (JTV519) inhibits Ca^<2+> leak by correcting the defective inter-domain interaction between the two domains in failing hearts. Here, we identified the K201-binding domain and diaracterizedtherole ofthis novel domain on RyR2 channel gating.
An assay using a quartz-crystal microbalance revealed that K201 specifically bound to recornbinant RyR2 fragment: 1741. 2270 in the 1-2750 region. By further analysis of the fragnent1741-2270, 201 was found to specifically bind to its sub-fragment2114-2149. Using the peptide matching this sub-fragment (DP2114-2149)as a carrier, the RyR2 was specifically labeled with methylcoumarin acetate(MCA). Moreover, of several recombinant RyR2 fragments, only fragment 2234-2750 was specifically MCA-labeled; this suggests that the K201 binding domain2114-2149 binds with domain 2234-2750. Addition of DP2114-2149 to the MCA-labeled SR interfered with the interaction between domain2114-2149 and domain2234-2750 causing domain unzipping, as evidenced by an increased accessibility of the bound MCA to a large-size fluorescence quencher. In failing cardiomyocytes, the frequency of spontaneous Ca^<2+> spark (CaSF) was much higher than normal cardiomyocytes (p<0.01), whereas incorporation of DP2114-2149 markedly decreased CaSF to normal level; the same effect as that produced by K201.
In conclusion, we first identified the K201-binding site as domain2114-2149 of RyR2 Interruption of the inter-domain interaction between the domain2114-2149 and central domain2234-2750 seems to mediate stabilization of RyR2 in failing hearts, which may lead to a novel therapeutic strategy against heart failure and perhaps lethal arrhythmia.
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[Journal Article] Identification of target domains of the cardiac ryanodine receptor to correct channel disorder in failing hearts2008
Author(s)
Yamamoto, T, Yano, M, Xu, X, Uchinoumi, H, Tateishi, H, Mochizuki, M, Oda, T, Kobayashi, S, Ikemoto, N, Matsuzaki, M
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Journal Title
Circulation 117(6)
Pages: 762-72
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] 「研究成果報告書概要(欧文)」より2007
Author(s)
Mochizuki, M, Yano, M, Oda, T, Tateishi, H, Kobayashi, S, Yamamoto, T, Ikeda, Y, Ohkusa, T, Ikemoto, N, Matsuzaki, M
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Journal Title
JAm Coll Cardiol 49(16)
Pages: 1722-32
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