Heart function and hemodynamic analysis for zebrafish embryos

Abstract

The Zebrafish has emerged to become a powerful vertebrate animal model for cardiovascular research in recent years. Its advantages include easy genetic manipulation, transparency, small size, low cost, and the ability to survive without active circulation at early stages of development. Sequencing the whole genome and identifying ortholog genes with human genome made it possible to induce clinically relevant cardiovascular defects via genetic approaches. Heart function and disturbed hemodynamics need to be assessed in a reliable manner for these disease models in order to reveal the mechanobiology of induced defects. This effort requires precise determination of blood flow patterns as well as hemodynamic stress (i.e., wall shear stress and pressure) levels within the developing heart. While traditional approach involves time-lapse brightfield microscopy to track cell and tissue movements, in more recent studies fast light-sheet fluorescent microscopes are utilized for that purpose. Integration of more complicated techniques like particle image velocimetry and computational fluid dynamics modeling for hemodynamic analysis holds a great promise to the advancement of the Zebrafish studies. Here, we discuss the latest developments in heart function and hemodynamic analysis for Zebrafish embryos and conclude with our future perspective on dynamic analysis of the Zebrafish cardiovascular system. Developmental Dynamics 246:868-880, 2017. V C 2017 Wiley Periodicals, Inc.

Validating the Paradigm That Biomechanical Forces Regulate Embryonic Cardiovascular Morphogenesis and Are Fundamental in the Etiology of Congenital Heart Disease

“…High-resolution 3D imaging of the transparent zebrafish embryo heart [ 265 ] as well as standard edge-detection methods [ 266 ] showed a negative chronotropic response to temperature and positive inotropic response to norepinephrine similar to chick [ 104 ] and rat [ 74 ] embryos. As with the chick and mouse embryo models, the availability of high-resolution imaging and hemodynamic instrumentation along with the ability to instrument the zebrafish embryo during rapid growth and morphogenesis led to a range of excellent studies related to the hemodynamic regulation of morphogenesis in normal zebrafish embryos ( Figure 17 B,C) [ 267 , 268 , 269 , 270 , 271 , 272 , 273 , 274 , 275 , 276 , 277 , 278 ], the impact of numerous molecular pathways on zebrafish embryo cardiac morphogenesis and function [ 167 , 279 , 280 ], and the inflammatory cellular response of the zebrafish embryonic heart to thermal injury [ 281 ]. Many of the zebrafish studies have validated paradigms developed in the chick embryo, including function–structure relationships, the importance of finely-tuned mechanical loading forces on valve and chamber morphogenesis, the important role of the neural crest in zebrafish cardiac morphogenesis [ 282 ], and the role of miRNAs in cardiac morphogenesis and function [ 283 , 284 ].…”

Using Zebrafish for Investigating the Molecular Mechanisms of Drug-Induced Cardiotoxicity

“…For hemodynamic evaluation, the most calculated parameters are heartbeat, cardiac output, fractional area change, fractional shortening, and vascular blood flow velocities [ 36 ]. These evaluations can be done by analyzing the embryos under an inverted or a stereo brightfield microscope [ 37 ]. In more advanced applications, novel techniques like computational fluid dynamics or particle image velocimetry can also be used for detailed hemodynamic analysis [ 38 , 39 ].…”

“…Determination of ventricular wall speeds is important for modelling cardiac muscle conditions such as cardiomyopathy on zebrafish. Levels of wall velocities are about 200–300 µ m/sec for 2 to 5 days postfaveolization (dpf) embryos [ 37 ]. Therefore, movies should be recorded at high speeds and image analysis is performed on these videos to find ventricular wall speeds and heart rate.…”

Contractile and hemodynamic forces coordinate Notch1b-mediated outflow tract valve formation

“…Thus, we provide developmental mechanotransduction mechanisms underlying Notch1b-mediated EndoMT in the OFT. genesis (8). Of their 2 cardiac valves, the AV valve has been the most studied, and the ventriculobulbar (VB) valve, which forms between the ventricle and the bulbus arteriosus, has received less attention.…”