He S, Wen Q, O'Shea C, Mu-U-Min R, Kou K, Grassam-Rowe A, Liu Y, Fan Z, Tan X, Ou X, Camelliti P, Pavlovic D, Lei M
Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China.
Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Front Physiol. 2019 Jun 25;10:755. doi: 10.3389/fphys.2019.00755. eCollection 2019.
Thin living tissue slices have recently emerged as a new tissue model for cardiac electrophysiological research. Slices can be produced from human cardiac tissue, in addition to small and large mammalian hearts, representing a powerful model system for preclinical and translational heart research. In the present protocol, we describe a detailed mouse heart transverse slicing and optical imaging methodology. The use of this technology for high-throughput optical imaging allows study of electrophysiology of murine hearts in an organotypic pseudo two-dimensional model. The slices are cut at right angles to the long axis of the heart, permitting robust interrogation of transmembrane potential (V) and calcium transients (CaT) throughout the entire heart with exceptional regional precision. This approach enables the use of a series of slices prepared from the ventricles to measure V and CaT with high temporal and spatial resolution, allowing (i) comparison of successive slices which form a stack representing the original geometry of the heart; (ii) profiling of transmural and regional gradients in V and CaT in the ventricle; (iii) characterization of transmural and regional profiles of action potential and CaT alternans under stress (e.g., high frequency pacing or β-adrenergic stimulation) or pathological conditions (e.g., hypertrophy). Thus, the protocol described here provides a powerful platform for innovative research on electrical and calcium handling heterogeneity within the heart. It can be also combined with optogenetic technology to carry out optical stimulation; aiding studies of cellular V and CaT in a cell type specific manner.
薄的活组织切片最近已成为心脏电生理研究的一种新的组织模型。除了小型和大型哺乳动物心脏外，切片还可以从人类心脏组织中制备，是临床前和转化性心脏研究的强大模型系统。在本方案中，我们描述了一种详细的小鼠心脏横向切片和光学成像方法。将该技术用于高通量光学成像，能够在器官型伪二维模型中研究小鼠心脏的电生理学。切片与心脏长轴成直角切割，从而能够以极高的数据精度对整个心脏的跨膜电位（V）和钙瞬变（CaT）进行有力的检测。这种方法能够使用从心室制备的一系列切片，以高时间和空间分辨率测量V和CaT，从而（i）比较形成代表心脏原始几何形状的堆栈的连续切片；（ii）描绘心室内V和CaT的跨壁和区域梯度；（iii）表征在应激（例如，高频起搏或β-肾上腺素能刺激）或病理状况（例如，肥大）下动作电位和CaT交替的跨壁和区域特征。因此，本文所述的方案为心脏内电和钙处理异质性的创新性研究提供了一个强大的平台。它还可以与光遗传学技术相结合进行光学刺激；以细胞类型特异性方式辅助研究细胞V和CaT。
