Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Union’s Horizon 2020 research and innovation programme - No 952166 (REPAIR) Regione Toscana - Bando Ricerca Salute 2018 - PERCARE project. Severe remodeling processes may occur in the heart due to both genetic and non-genetic diseases. Structural remodeling, such as collagen deposition (fibrosis) and cellular misalignment, can affect electrical conduction at different orders of magnitude and, eventually, lead to arrhythmias. In this scenario, arrhythmogenic cardiomyopathy (ACM) is an inherited heart disease that involves ventricular dysfunction, arrhythmias, and localized replacement of contractile fibers with fibrofatty scar tissue. Unfortunately, nowadays, predicting the impact of fine structural alterations on the electrical dysfunction in entire organs is challenging, due to the inefficacy of standard imaging methods in performing high-resolution three-dimensional reconstructions in massive tissues. In this work, we developed a new full-optical correlative approach to quantify and integrate the electrical dysfunctions with three-dimensional structural reconstructions of entire hearts, both in controls and in a mouse model of ACM. We combined optical mapping of the action potential propagation (APP) with advances in tissue clearing and light-sheet microscopy techniques. First, we employed an optical platform to map and analyze the APP in Langendorff-perfused hearts. Then, we optimized the SHIELD procedure for the clearing of cardiac tissue, thus converting the previously electrically characterized samples into well-preserved and fully-transparent specimens. A high-throughput light-sheet microscope has been developed following the mesoSPIM project: the conceived microscope allows the reconstruction of the whole mouse heart with a micrometric resolution allowing fine quantification of myocytes alignment and fibrosis deposition across the organ. Finally, we developed a software pipeline that employs high-resolution 3D images to analyze and co-register APP maps with the 3D anatomy, contractile fibers disarray, and fibrosis deposition on each heart. We believe that this promising methodological framework will allow clarifying the involvement of fine structural alterations in the electrical dysfunctions, thus enabling a unified investigation of the structural causes that lead to electrical and mechanical alterations after the tissue remodeling.

中文翻译：

---

通过先进的光学方法关联致心律失常小鼠心脏的电功能障碍和结构重塑

资金致谢 资金来源类型：公共拨款——欧盟资金。主要资金来源：欧盟的 Horizo​​n 2020 研究和创新计划 - No 952166 (REPAIR) Regione Toscana - Bando Ricerca Salute 2018 - PERCARE 项目。由于遗传和非遗传疾病，心脏可能会发生严重的重塑过程。结构重塑，例如胶原沉积（纤维化）和细胞错位，会影响不同数量级的电传导，并最终导致心律失常。在这种情况下，致心律失常性心肌病 (ACM) 是一种遗传性心脏病，涉及心室功能障碍、心律失常和局部用纤维脂肪瘢痕组织替代收缩纤维。不幸的是，如今，预测精细结构改变对整个器官电功能障碍的影响具有挑战性，因为标准成像方法无法在大块组织中进行高分辨率 3D 重建。在这项工作中，我们开发了一种新的全光学相关方法来量化和整合电功能障碍与整个心脏的三维结构重建，无论是在控制还是在 ACM 的小鼠模型中。我们将动作电位传播 (APP) 的光学映射与组织清除和光片显微镜技术的进步相结合。首先，我们采用光学平台来绘制和分析 Langendorff 灌注心脏中的 APP。然后，我们优化了清除心脏组织的 SHIELD 程序，从而将先前的电特性样品转换为保存完好且完全透明的样品。在 mesoSPIM 项目之后开发了一种高通量光片显微镜：构思的显微镜允许以微米分辨率重建整个小鼠心脏，从而可以精细量化整个器官的肌细胞排列和纤维化沉积。最后，我们开发了一个软件管道，该管道使用高分辨率 3D 图像来分析 APP 地图并将其与每颗心脏上的 3D 解剖结构、收缩纤维紊乱和纤维化沉积进行配准。我们相信，这种有前途的方法论框架将有助于阐明精细结构改变对电功能障碍的影响，