Xu Rui, Du Shaojun
Department of Biochemistry and Molecular Biology, Institute of Marine and Environmental Technology, University of Maryland School of Medicine, Baltimore, MD, United States.
Front Cell Dev Biol. 2021 Oct 26;9:746818. doi: 10.3389/fcell.2021.746818. eCollection 2021.
Lifeact-GFP is a frequently used molecular probe to study F-actin structure and dynamic assembly in living cells. In this study, we generated transgenic zebrafish models expressing Lifeact-GFP specifically in cardiac muscles to investigate the effect of Lifeact-GFP on heart development and its application to study cardiomyopathy. The data showed that transgenic zebrafish with low to moderate levels of Lifeact-GFP expression could be used as a good model to study contractile dynamics of actin filaments in cardiac muscles . Using this model, we demonstrated that loss of Smyd1b, a lysine methyltransferase, disrupted F-actin filament organization in cardiomyocytes of zebrafish embryos. Our studies, however, also demonstrated that strong Lifeact-GFP expression in cardiomyocytes was detrimental to actin filament organization in cardiomyocytes that led to pericardial edema and early embryonic lethality of zebrafish embryos. Collectively, these data suggest that although Lifeact-GFP is a good probe for visualizing F-actin dynamics, transgenic models need to be carefully evaluated to avoid artifacts induced by Lifeact-GFP overexpression.
Lifeact-GFP是一种常用于研究活细胞中F-肌动蛋白结构和动态组装的分子探针。在本研究中，我们构建了在心肌中特异性表达Lifeact-GFP的转基因斑马鱼模型，以研究Lifeact-GFP对心脏发育的影响及其在心肌病研究中的应用。数据表明，低至中等水平表达Lifeact-GFP的转基因斑马鱼可作为研究心肌中肌动蛋白丝收缩动力学的良好模型。利用该模型，我们证明了赖氨酸甲基转移酶Smyd1b的缺失破坏了斑马鱼胚胎心肌细胞中F-肌动蛋白丝的组织。然而，我们的研究也表明，心肌细胞中强烈的Lifeact-GFP表达对心肌细胞中肌动蛋白丝的组织有害，导致斑马鱼胚胎心包水肿和早期胚胎致死。总体而言，这些数据表明，尽管Lifeact-GFP是可视化F-肌动蛋白动力学的良好探针，但转基因模型需要仔细评估，以避免Lifeact-GFP过表达引起的假象。
