Investigation of arrhythmias in anthropomorphized murine cardiac myocytes.

描述(申请人提供)：本申请提出并利用了一种新的电生理学技术，即拟人化动态钳(ADC)，它增加了基因工程小鼠在遗传性心律失常研究中的应用。遗传性通道病，如长QT综合征，是已知的晕厥、心脏骤停和心源性猝死的原因。在过去的十年里，在识别患者的致病突变方面取得了很大的进展。已经产生了这些突变的几个小鼠模型；然而，由于小鼠和人类心脏电生理动力学之间的主要差异，很难将小鼠的突变表型推断为人类疾病。本申请中提出的技术使用计算生物学-电生理学的混合方法，以便在人类动作电位波形的背景下检查分离的小鼠心肌细胞。ADC是一种动态的全细胞膜片钳技术，它将分离的小鼠心肌细胞与计算模型相结合。这些模型计算了一种补偿电流，它将允许小鼠心肌细胞经历自由运行的人膜电位。这将允许研究引起心律失常的事件，例如去极化后的早期，这些事件通常在短鼠动作电位的背景下被掩盖。初步的模拟研究表明，ADC可用于研究引入小鼠心肌细胞的突变对人类动作电位的影响。ADC可广泛应用于遗传性通道病的小鼠模型。此外，它与NHLBI战略计划直接相关，该战略计划特别呼吁开发能够帮助揭示心脏疾病的病理生理机制的计算和实验技术。摘要：心脏正常节律紊乱(心律失常)会导致严重的健康后果，包括死亡。一些人遗传了基因突变，增加了发生心律失常的可能性。为了研究这些突变，已经制造了基因工程小鼠；然而，小鼠和人类的心率之间存在重大差异。这项申请中提出的新技术将把小鼠心脏细胞的行为转变为更接近人类的状态。使用这项技术对小鼠的研究应该会对心律疾病的机制产生新的见解。

DESCRIPTION (provided by applicant): This application presents and utilizes a new electrophysiology technique, the anthropomorphizing dynamic clamp (ADC) that increases the utility of genetically engineered mice in studies of inherited cardiac arrhythmias. Inherited channelopathies, such as the Long QT syndrome, are known causes of syncope, cardiac arrest, and sudden cardiac death. In the past decade, great progress has been made in identifying disease-causing mutations in patients. Several mouse models of these mutations have been produced; however, extrapolation of a mouse mutant phenotype to human disease is difficult because of the major differences between mouse and human cardiac electrophysiology dynamics. The technique proposed in this application uses a hybrid computational biology-electrophysiology method in order to examine isolated mouse myocytes in the context of a human action potential waveform. The ADC is a dynamic whole-cell patch clamp technique that couples an isolated murine cardiac myocyte to computational models. These models calculate a compensatory current which will allow a mouse myocyte to undergo a free-running human membrane potential. This will permit investigation of arrhythmogenic events, such as early after depolarizations, which are normally masked in the context of the short mouse action potential. Preliminary modeling studies have demonstrated that the ADC can be used to study the effects of a mutation introduced into a mouse myocyte on the human action potential. The ADC could be applied to a wide-range of mouse models of inherited channelopathies. Also, it is directly relevant to the NHLBI strategic plan, which specifically calls for the development of computational and experimental techniques that can help uncover the pathophysiologic mechanisms of cardiac diseases. Lay Summary: Disturbances in the normal rhythm of the heart (arrhythmias) can lead to serious health consequences, including death. Some people have inherited mutations which increase the likelihood of arrhythmias. Genetically engineered mice have been made in order to study these mutations; however, major differences exist between mouse and human heart rhythms. The new technique proposed in this application will convert the behavior of mouse heart cells to a more human-like state. Studies of mice using this technique should yield new insights into the mechanisms of heart rhythm diseases.