Caño-Carrillo Sheila, Garcia-Padilla Carlos, Aranega Amelia E, Lozano-Velasco Estefania, Franco Diego
Cardiovascular Development Group, Department of Experimental Biology, University of Jaen, 23071 Jaen, Spain.
Fundación Medina, 18016 Granada, Spain.
Int J Mol Sci. 2024 Nov 30;25(23):12904. doi: 10.3390/ijms252312904.
Cardiac development is a complex developmental process. The early cardiac straight tube is composed of an external myocardial layer and an internal endocardial lining. Soon after rightward looping, the embryonic heart becomes externally covered by a new epithelial lining, the embryonic epicardium. A subset of these embryonic epicardial cells migrate and colonize the embryonic myocardium, contributing to the formation of distinct cell types. In recent years, our understanding of the molecular mechanisms that govern proepicardium and embryonic epicardium formation has greatly increased. We have recently witnessed the discovery of a novel layer of complexity governing gene regulation with the discovery of non-coding RNAs. Our laboratory recently identified three distinct lncRNAs, adjacent to the , and chicken gene loci, with enhanced expression in the proepicardium that are distinctly regulated by Bmp, Fgf and thymosin β4, providing support for their plausible implication in epicardial formation. The expression of lncRNAs was analyzed in different chicken and mouse tissues as well as their subcellular distribution in chicken proepicardial, epicardial, ventricle explants and in different murine cardiac cell types. lncRNA transcriptional regulation was analyzed by using siRNAs and expression vectors of different transcription factors in chicken and mouse models, whereas antisense oligonucleotides were used to inhibit expression. Furthermore, RT-qPCR, immunocytochemistry, RNA pulldown, Western blot, viability and cell migration assays were conducted to investigate the biological functions of and . We demonstrated that in chicken and its putative conserved homologue in mice are widely distributed in different embryonic and adult tissues and distinctly regulated by cardiac-enriched transcription factors, particularly and . Furthermore, silencing assays demonstrated that mouse , but not chicken , is essential for epicardial, but not endocardial or myocardial, cell migration. Such processes are governed by partnering with Myl9, promoting cytoskeletal remodeling. Our data show that plays a pivotal role in epicardial cell migration essential for heart regeneration under these experimental conditions.
心脏发育是一个复杂的发育过程。早期的心脏直管由外层心肌层和内层心内膜衬里组成。向右环化后不久，胚胎心脏被一层新的上皮衬里，即胚胎心外膜所覆盖。这些胚胎心外膜细胞的一个亚群迁移并定殖于胚胎心肌，促进不同细胞类型的形成。近年来，我们对控制前心外膜和胚胎心外膜形成的分子机制的理解有了很大提高。最近，随着非编码RNA的发现，我们见证了基因调控中一个新的复杂层面的发现。我们实验室最近在鸡的、和基因座附近鉴定出三种不同的长链非编码RNA（lncRNA），它们在前心外膜中表达增强，并受到骨形态发生蛋白（Bmp）、成纤维细胞生长因子（Fgf）和胸腺素β4的明显调控，这为它们在心外膜形成中的可能作用提供了支持。分析了lncRNA在不同鸡和小鼠组织中的表达及其在鸡前心外膜、心外膜、心室外植体和不同小鼠心脏细胞类型中的亚细胞分布。通过在鸡和小鼠模型中使用小干扰RNA（siRNA）和不同转录因子的表达载体来分析lncRNA的转录调控，而使用反义寡核苷酸来抑制表达。此外，进行了逆转录定量聚合酶链反应（RT-qPCR）、免疫细胞化学、RNA下拉、蛋白质免疫印迹、活力和细胞迁移试验，以研究和的生物学功能。我们证明，鸡中的及其在小鼠中的假定保守同源物在不同的胚胎和成年组织中广泛分布，并受到心脏富集转录因子，特别是和的明显调控。此外，沉默试验表明，小鼠中的对于心外膜细胞迁移至关重要，但对心内膜或心肌细胞迁移并非如此。这些过程通过与肌球蛋白轻链9（Myl9）协同作用来控制，促进细胞骨架重塑。我们的数据表明，在这些实验条件下，对于心脏再生所必需的心外膜细胞迁移起着关键作用。
