Fibrinogen-like protein 2 contributes to normal murine cardiomyocyte maturation and heart development
Fibrinogen-like protein 2 contributes to normal murine cardiomyocyte maturation and heart development
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纤维蛋白原样蛋白 2 有助于正常小鼠心肌细胞成熟和心脏发育
DOI：
10.1113/ep089450
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发表时间：
2021-05-27
影响因子：
2.7
通讯作者：
Wang, Zhaohui
中科院分区：
文献类型：
--
作者：
Fan, Cheng;Chen, Hong;Wang, Zhaohui
新发现这项研究的中心问题是什么？纤维蛋白原样蛋白2 （FGL2）在小鼠心肌细胞成熟中的作用？主要发现是什么及其重要性？这是第一个显示Fgl2基因敲除和心脏特异性Fgl2缺失都会引发早期死亡和扩张性心肌病的研究。通过使用腺相关病毒（AAV）介导的CRISPR/ cas9体细胞诱变系统，研究人员证实，心脏特异性FGL2缺失诱导心室扩张和重构，并破坏心肌细胞正常的肥厚生长和多倍体化。此外，研究表明，信号转导和转录激活因子3、细胞外信号调节激酶1和2以及成纤维细胞生长因子2信号的调节与fgl2介导的心功能障碍的丧失有关。这些结果表明FGL2是心肌细胞成熟的重要决定因素。晚育哺乳动物在出生后的最初几周内，出生后心肌细胞（CMs）经历了巨大的变化，包括细胞体积增大、细胞周期消退和多倍体化，从而成为成熟的CMs。这一过程中的异常可能会破坏成人CMs的基本收缩性和同步性，导致各种心脏疾病。然而，CM成熟的机制尚不清楚。纤维蛋白原样蛋白2 （FGL2）是一种免疫凝血剂，参与多种细胞类型的成熟。然而，很少有证据表明FGL2在CM成熟中的作用。在本研究中，我们观察到全球Fgl2（-/-）幼崽在P28之前具有高致死率和心功能障碍。为了进一步确认FGL2的表型并研究FGL2缺乏的机制，我们使用了一种基于腺相关病毒（AAV）介导的CRISPR/ cas9体细胞诱变系统，在CMs中特异性地产生FGL2的功能缺失突变。我们设计了两种专门针对Fgl2外显子1的引导rna (gRNAs)，并生产了Fgl2- grna AAV9，并将其传递给新生Cas9小鼠。在这里，我们证明了FGL2 - grna AAV9递送后心脏中FGL2的有效消耗。与全球Fgl2（-/-）小鼠的研究结果一致，我们观察到aav9介导的Fgl2耗竭会引发早期死亡和扩张性心肌病。此外，FGL2的缺失扰乱了成熟CMs的正常肥厚生长和多倍体化。此外，我们发现信号转导和转录激活因子3、细胞外信号调节激酶1和2以及成纤维细胞生长因子2信号的调节与FGL2缺陷介导的心功能障碍有关。在这里，我们证明了FGL2在体内成熟的CM中成功地耗尽，并表明FGL2是正常CM成熟的重要决定因素。
New FindingsWhat is the central question of this study? What is the role of fibrinogen-like protein 2 (FGL2) in murine cardiomyocyte maturation?What is the main finding and its importance? This is the first study showing both global Fgl2 knockout and cardiac-specific FGL2 deletion trigger early death and dilated cardiomyopathy. By using an adeno-associated virus (AAV)-mediated CRISPR/Cas9-based somatic mutagenesis system, it was demonstrated that cardiac-specific FGL2 depletion induces ventricular dilatation and remodelling, and disrupts the normal hypertrophic growth and polyploidization of cardiomyocytes. In addition, it was shown that modulation of signal transducer and activator of transcription 3, extracellular signal-regulated kinases 1 and 2 and fibroblast growth factor 2 signalling is associated with loss-of-FGL2-mediated cardiac dysfunction. These results suggest FGL2 is an important determinant of cardiomyocyte maturation.In the first few weeks after birth in altricial mammals, postnatal cardiomyocytes (CMs) undergo dramatic changes, including cell volume enlargement, cell cycle withdrawal and polyploidization to become mature CMs. Aberrations in this process could disrupt the essential contractility and synchronization of adult CMs, leading to various heart diseases. However, the mechanism of CM maturation is poorly understood. Fibrinogen-like protein 2 (FGL2) is an immune coagulant which participates in maturation of multiple cell types. However, little evidence exists regarding a role of FGL2 in CM maturation. In this study, we observed that global Fgl2(-/-) pups had high lethality and suffered from cardiac dysfunction before P28. To further confirm the phenotype and study the mechanisms upon FGL2 deficiency, we used an adeno-associated virus (AAV)-mediated CRISPR/Cas9-based somatic mutagenesis system to generate loss-of-function mutations of Fgl2 specifically in CMs. We designed two guide RNAs (gRNAs) exclusively targeting Fgl2 exon1 and produced Fgl2-gRNA AAV9 to deliver to neonatal Cas9 mice. Here, we demonstrated the efficient FGL2 depletion in the heart after Fgl2-gRNA AAV9 delivery. Consistent with the findings in global Fgl2(-/-) mice, we observed AAV9-mediated FGL2 depletion triggered early death and dilated cardiomyopathy. In addition, FGL2 depletion perturbed the normal hypertrophic growth and polyploidization of maturing CMs. Furthermore, we found modulation of signal transducer and activator of transcription 3, extracellular signal-regulated kinases 1 and 2 and fibroblast growth factor 2 signalling was associated with FGL2 deficiency-mediated cardiac dysfunction. Here, we demonstrate the successful depletion of FGL2 in maturing CMs in vivo and show FGL2 is an important determinant for normal CM maturation.