Ca ((2+) 関連のシグナル伝達とタンパク質のリン酸化異常は,電気嵐の新しい実験モデルにおいて中心的な役割を果たしています
Yukiomi Tsuji1, Mayumi Hojo, Niels Voigt
1Department of Cardiovascular Research, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan. y-tsuji@hh.iij4u.or.jp
Circulation
|May 11, 2011
まとめ
埋め込み心変容器-除細動器患者における電気嵐 (ES) は,Ca2+に関連するタンパク質変化を伴う. この研究では,Ca2+) /カルモジュリン依存タンパク質キナーゼIIの活性化とフォスフォランバン脱酸化が,ES不律の促進と機能障害に寄与することを明らかにしています.
科学分野:
- 心臓病学 心臓病学
- 分子生物学は分子生物学である.
- 電気生理学 電気生理学
背景:
- 電気嵐 (ES) は, implantable cardioverter-defibrillator患者における深刻な合併症である.
- ESの基礎となる分子機構は,依然として十分に理解されていない.
- この研究は,ESを調査するための新しい実験モデルを導入しています.
研究 の 目的:
- ESの発達におけるカルシウム (Ca2+) 処理タンパク質の変化の役割を調査する.
- ESにおける悪循環の分子基礎を解明する.
主な方法:
- 完全な心房静脈ブロックとインプラント可能な心臓変容器-除細動器のインプラントを備えたウサギのモデルが使用されました.
- Ca2+ハンドリングタンパク質の発現とリン酸化は,心室組織で分析されました.
- カルモジュリン抗体 (W-7) がESと心臓機能に及ぼす効果を評価した.
主要な成果:
- ESのウサギは,Ca2+/カルモジュリン依存タンパク質キナーゼII (CaMKII) ハイパーフォスホルリレーションとフォスホラムバンデフォスホルリレーションが増加した.
- 収縮性機能障害は,非ESのウサギと比較して,ESのウサギでは有意に大きかった.
- カルモジュリン抗体治療は,CaMKII高酸化を減少させ,不律律を抑制し,心臓機能を改善しました.
結論:
- ESは,CaMKIIの有意な活性化と,フォスフォランバンの脱酸化と関連しています.
- これらの分子変化は,ESにおける心律乱や機械機能障害の促進に寄与する.
- ターゲティングのCaMKIIは,ESの管理のための治療戦略を提供することができます.
関連する概念動画
01:16Calmodulin-dependent Signaling
Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
01:22Amplifying Signals via Enzymatic Cascade
When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze the...
01:28Action Potential: Phases of Stimulation
The action potential is a complex electrical event that occurs in excitable cells, such as neurons and muscle cells. It consists of several distinct phases, each with specific characteristics.
Resting Phase:
In this phase, the cell's membrane is at its resting potential, typically around -70 millivolts (mV) for neurons. Inside the cell, there is a higher concentration of potassium ions (K+) and a lower concentration of sodium ions (Na+). Voltage-gated sodium channels are closed, and...
Resting Phase:
In this phase, the cell's membrane is at its resting potential, typically around -70 millivolts (mV) for neurons. Inside the cell, there is a higher concentration of potassium ions (K+) and a lower concentration of sodium ions (Na+). Voltage-gated sodium channels are closed, and...
01:19Interactions Between Signaling Pathways
Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
01:24Intracellular Signaling Cascades
Once a ligand binds to a receptor, the signal is transmitted through the membrane and into the cytoplasm. The continuation of a signal in this manner is called signal transduction. Signal transduction only occurs with cell-surface receptors, which cannot interact with most components of the cell, such as DNA. Only internal receptors can interact directly with DNA in the nucleus to initiate protein synthesis. When a ligand binds to its receptor, conformational changes occur that affect the...
01:19The Role of Ion Channels in Neuronal Computation
A postsynaptic neuron usually receives numerous impulses from several other presynaptic neurons. The axon hillock of the postsynaptic neuron integrates all these signals and determines the likelihood of firing an action potential.
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential.
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential.