Shear stress and light-field to elucidate the initiation of cardiac outflow tract

切应力和光场对心脏流出道起始的解释 生物机械力调节心脏形态发生和机械敏感信号突变 这些途径会导致先天性心脏缺陷。在之前的资金周期中，我们的团队定制了一款Light- 具有亚体素分辨率的薄片荧光显微镜(LSFM)可提高所需的轴向分辨率 提供广阔的视野。这种激光光学系统允许对脉动与振荡剪切应力进行成像- 介导Notch信号以启动心内膜小梁形成。我们演示了空间(/x)和 剪切力的时间(/t)变化调制Notch-EPhinB2-Neuregulin-1信号转导 心内膜激活Erb-B2受体酪氨酸激酶(ErbB2)，促进小梁细胞增殖。 通过整合LSFM、计算和转基因模型，我们进一步证实了小梁效应是消散的。 心内切应力产生动能，从而减轻心脏重塑。然而，它仍然 尚不清楚心肌收缩能力降低或心内血流改变的后果是什么 瓣膜形态发生的动力学研究。因此，我们寻求将光片(贝塞尔-高斯光束阵列)与 一种新的光场(微透镜阵列)。前者提供非衍射光，而后者提供 容量检测是心肌收缩能力和心内血流动力学成像的一种范式转变 在流出道(OFT)。我们的初步研究表明，剪切力介导的Notch1b在子宫内膜中的表达 OFT的心内膜调节内皮-间充质转化(EndoMT)；然而， 心肌收缩能力与心内切应力相互作用的力学转导机制 相互作用形成二尖瓣，随后对多尖瓣的重塑仍然难以捉摸。因此，我们的 假设是新的光场系统与成像计算的集成增强了时空 将心肌收缩与调节心脏内血流动力学脱钩所需的分辨率 Notch1b-EndoMT介导OFT瓣膜形态发生。在目标1中，我们计划将光片与 用于OFT瓣膜形成的四维体成像的新光场系统我们的目标是夺取 心肌收缩能力和心内切应力的一次快照。在目标2中，我们将演示 心脏内切应力与瓣膜形态发生相关的心肌收缩能力之间的相互作用。我们的 目标是将血流动力学剪切力与介导Notch1b介导的EndoMT的收缩力量分离。在……里面 目的3，我们将确定剪应力和收缩在Notch1b介导下的相对作用 EndoMT。我们的目标是阐明收缩能力和心内应激在传递Notch1b- 二尖瓣形成背后的EndoMT信号。总体而言，我们的团队的目标是建立微型 心内血流动力学和心肌收缩功能相互作用以调节OFT瓣膜的环境 形成，对主动脉瓣病变具有临床意义。

Shear Stress and Light-Field to Elucidate the Initiation of Cardiac Outflow Tract Biomechanical forces modulate cardiac morphogenesis, and mutations in mechano-sensitive signaling pathways result in congenital heart defects. During the previous funding cycle, our team custom-built a Light- Sheet Fluorescence Microscopy (LSFM) with sub-voxel resolution to enhance axial resolution needed to provide a large field-of-view. This laser optical system allowed for imaging pulsatile vs. oscillatory shear stress- mediated Notch signaling to initiate endocardial trabeculation. We demonstrated that spatial (/x) and temporal (/t) variations in shear stress modulates Notch-EphrinB2-Neureguilin-1 signaling in the endocardium to activate erb-B2 receptor tyrosine kinase (ErbB2) that promotes proliferation of trabeculation. By integrating LSFM, computation, and transgenic models, we further established that trabeculation dissipates intracardiac shear stress-generated kinetic energy; thus, mitigating ventricular remodeling. However, it remains unclear what would be the consequences of reduced myocardial contractility or altered intracardiac flow dynamics on valve morphogenesis. Thus, we seek to integrate light-sheet (Bessel-Gaussian beam arrays) with a new 2) light-field (microlens array). The former provides non-diffracting illumination, and the latter provides volumetric detection as a paradigm shift to image both myocardial contractility and intracardiac flow dynamics in the outflow tract (OFT). Our preliminary study reveals that shear-mediated Notch1b expression in the endocardium of OFT regulates endothelial-to-mesenchymal transition (EndoMT); however, the mechanotransduction causation whereby myocardial contractility and intracardiac shear stress reciprocally interact to form bicuspid valves and subsequent remodeling to multi-cuspid valves remains elusive. Thus, our hypothesis is that integration of the new light-field system with imaging computation enhances spatiotemporal resolution needed to decouple myocardial contraction from intracardiac flow dynamics that modulates Notch1b-EndoMT to mediate valve morphogenesis in the OFT. In Aim 1, we plan to integrate light-sheet with the new light-field system for 4-D volumetric imaging of valve formation in the OFT. Our goal is to capture myocardial contractility and intracardiac shear stress at one snapshot. In Aim 2, we will demonstrate the interaction between intracardiac shear stress and myocardial contractility underlying valve morphogenesis. Our goal is to decouple hemodynamic shear from contractile forces that mediate Notch1b-mediated EndoMT. In Aim 3, we will determine the relative role of shear stress and contractility underlying Notch1b-mediated EndoMT. Our goal is to elucidate the relative role of contractility and intracardiac stress to transmit Notch1b- EndoMT signaling underlying bicuspid-valve formation. Overall, our team aims to establish the micro- environment in which intracardiac flow dynamics and myocardial contractility interact to modulate OFT valve formation, with clinical significance to aortic valvular disease.