Novel Therapeutic Strategy for Heart Failure : Molecular Mechanism underlying the Regulation of Ca^<2+> Signaling in the Heart

心力衰竭的新治疗策略：心脏中 Ca^<2> 信号传导调节的分子机制

• 批准号: 13307065
• 负责人: NAGAO Taku
• 金额: $ 34.86万
• 依托单位: National Institute of Health Sciences
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13307065/
• 关键词: reactive oxygen species; oxidative stress; G protein; seven transmembrane; Ca^<2+> signaling; C^<2+> channel; cardiac myocyte; cardiac hypertrophy; G-タンパク質; システイン; 興奮収縮連関; カルシウムシグナリング; カルシウムチャネル; リアノジン受容体

1) Treatment with H_2O_2 activates G_I/G_o in rat neonatal ventricular myocytes. We found that H_2O_2 modifies Cys^<287> and Cys^<326> of G_<αi>. Angiotensin II stimulation generated ROS and induced the activation of MAP kinase. The elimination of ROS by the co expression of peroxiredoxn II abolished JNK activation induced by angiotensin II without affecting ERK or p38 MAPK activities. These results indicate that ROS, produced by receptor stimulation, serves as an intracellular mediator linking the receptor stimulation and the activation of MARK (JNK).2) Aiming at elucidating the molecular mechanism underlying the gating modulation of L-type Ca^<2+> channels by Ca^<2+> channel modulators, we searched for the DHP binding sites in L-type Ca^<2+> channel a_<1C> subunit. We identified the two key residues, Phe^<1112> and Ser^<1115> in IIIS5-S6 pore-forming region. The double mutant Ca^<2+> channel (F1112A/S115A) was insensitive to Ca^<2+> channel agonists, and weakly blocked by both Ca^<2+ … More > channel agonists and antagonists. We proposed a novel model for the modulation of Ca^<2+> channel gating by the binding of Ca^<2+> channel modulators at the pore-forming region of Ca^<2+> channel α_<1C> subunit.3) We investigated the physiological role of the privileged cross-communication between L-type Ca^<2+> channels and ryanodine receptors. We found that Ca^<2+> channels function as a sensor to the SR Ca^<2+> content to manipulate APD and the total Ca^<2+> influx through Ca^<2+> channels during APs, via the Ca^<2+>-dependent inactivation of Ca^<2+> channels produced by proximal Ca^<2+>-induced Ca^<2+> release CICR-dependent CDI, to ensure the efficacy of CICR.4) In order to elucidate the physiological role of Na^+-Ca^<2+> exchanger (NCX) in cardiac excitation-contraction coupling, we examined the Ca^<2+> signaling in NCX knockout heterozygous mouse heart. We found that the forward mode NCX activity plays a physiologically important role in the regulation of the SR Ca^<2+> content. Less

1)H_2O_2激活乳鼠心室肌细胞G_I/G_o。我们发现H_2O_2修饰了<287><326>G_&lt;αi&gt;的Cys^和Cys^。血管紧张素II刺激产生ROS并诱导MAP激酶活化。通过共表达过氧化物酶II消除ROS可消除血管紧张素II诱导的JNK活化，而不影响ERK或p38 MAPK活性。这些结果表明，由受体刺激产生的ROS是连接受体刺激和MARK（JNK）激活的细胞内介质。2）为了阐明Ca^2+通道调节剂对L-型Ca^2+通道门控调节的分子机制，我们在L-型Ca^2+通道α亚基上寻找DHP结合位点<1C>。我们确定了IIIS 5-S6成孔区域中的两个关键残基Phe^<1112>和Ser^<1115>。双突变型Ca^2+通道（F1112 A/S115 A）对Ca^2+通道激动剂不敏感，并且被两种Ca^2+通道都微弱地阻断。 ...更多信息 &gt;通道激动剂和拮抗剂。我们提出了一种新的模型，即通过Ca^2+通道调节剂与Ca ^2+通道α_亚基的成孔区结合来调节Ca^2+通道门控<1C>。3）我们研究了L型Ca^2+通道与ryanodine受体之间的特殊交叉通讯的生理作用。我们发现，Ca^2+通道作为SR Ca^2+含量的传感器，通过近端Ca^2+诱导的Ca^2+释放产生的Ca^2+通道的Ca^2+依赖性失活CICR依赖性CDI，4）为了阐明Na^+-Ca^&lt;2+&gt;交换体（NCX）在心脏兴奋-收缩偶联中的生理作用，我们检测了NCX敲除杂合子小鼠心脏中的Ca^&lt;2+&gt;信号。我们发现NCX的正向活动在调节肌浆网Ca^&lt;2+&gt;含量中起着重要的生理作用。少

项目成果

Hagiwara M. et al.: "High affinity binding of [^3H]DTZ323 to the diltiazem-binding site of L-type Ca^<2+> channels"Eur. J. Pharmacol.. (in press). (2003)

Hagiwara M.等人：“[ 3 H]DTZ323与L型Ca 2 通道的地尔硫卓结合位点的高亲和力结合”Eur。

Sugimoto Y. et al.: "β_1-selective agonist (-)-1-(3,4-dimethoxyphenetylamino)-3-(3,4-dihydroxy)-2-propanol[(-)-RO363] differentially interacts with key amino acids responsible for β_1-selective binding in resting and active states"J. Pharmacol. Exp. Ther.

Sugimoto Y. 等人：“β_1-选择性激动剂 (-)-1-(3,4-二甲氧基苯乙氨基)-3-(3,4-二羟基)-2-丙醇[(-)-RO363] 与关键药物有不同的相互作用在静息和活动状态下负责 β_1-选择性结合的氨基酸“J. Pharmacol. Exp. Ther.

Isogaya M. et al.: "Enhanced cAMP response of naturally occurring mutant of human β_3-adrenergic receptor"Jp. J. Pharmacol.. 88:(3). 314-318 (2002)

Isogaya M.等人：“人β_3-肾上腺素受体天然突变体的增强的cAMP反应”Jp.J.Pharmacol..88：(3)(2002)。

Yamaguchi, S. et al.: "Key roles of Phe^<1112> and Ser^<1115> in the pore-forming IIIS5-S6 linker of L-type Ca^<2+> channel α_<1C> subunit (Cav1.2) in binding of dihydropyridines and action of Ca^<2+> channel agonists"Mol.Phamracol.. (in press). (2003)

Yamaguchi, S. 等人：“Phe^<1112> 和 Ser^<1115> 在 L 型 Ca^<2+> 通道 α_<1C> 亚基的成孔 IIIS5-S6 连接子中的关键作用 (Cav1 .2)二氢吡啶的结合和Ca 2+ 通道激动剂的作用“Mol.Phamracol..(正在出版)。(2003)

Nishida, M., Takagahara, S., Maruyama, Y., Sugimoto, Y., Nagao, T. and Kurose, H.: "Gβγ counteracts Gα_q signaling upon β_1-adrenergic receptor stimulation"Biochem. Biophys. Res. Commun.. 291. 995-1000 (2002)

Nishida, M.、Takagahara, S.、Maruyama, Y.、Sugimoto, Y.、Nagao, T. 和 Kurose, H.：“Gβγ 对抗 β_1-肾上腺素受体刺激时的 Gα_q 信号传导”Biochem。 .291.995-1000（2002）