de Almeida Patrícia Gomes, Pinheiro Gonçalo G, Nunes Andreia M, Gonçalves André B, Thorsteinsdóttir Sólveig
Centre for Ecology, Evolution and Environmental Change (cE3c), Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal.
Dev Dyn. 2016 Apr;245(4):520-35. doi: 10.1002/dvdy.24391. Epub 2016 Feb 17.
Fibronectin extracellular matrix is essential for embryogenesis. Its assembly is a cell-mediated process where secreted fibronectin dimers bind to integrin receptors on receiving cells, which actively assemble fibronectin into a fibrillar matrix. During development, paracrine communication between tissues is crucial for coordinating morphogenesis, typically being mediated by growth factors and their receptors. Recent reports of situations where fibronectin is produced by one tissue and assembled by another, with implications on tissue morphogenesis, suggest that fibronectin assembly may also be a paracrine communication event in certain contexts.
Here we addressed which tissues express fibronectin (Fn1) while also localizing assembled fibronectin matrix and determining the mRNA expression and/or protein distribution pattern of integrins α5 and αV, α chains of the major fibronectin assembly receptors, during early chick and mouse development. We found evidence supporting a paracrine system in fibronectin matrix assembly in several tissues, including immature mesenchymal tissues, components of central and peripheral nervous system and developing muscle.
Thus, similarly to growth factor signaling, fibronectin matrix assembly during early development can be both autocrine and paracrine. We therefore propose that it be considered a cell-cell communication event at the same level and significance as growth factor signaling during embryogenesis.
纤连蛋白细胞外基质对胚胎发育至关重要。其组装是一个细胞介导的过程，分泌的纤连蛋白二聚体与接收细胞上的整合素受体结合，接收细胞将纤连蛋白积极组装成纤维状基质。在发育过程中，组织间的旁分泌通讯对于协调形态发生至关重要，通常由生长因子及其受体介导。最近有报道称，纤连蛋白由一种组织产生并由另一种组织组装，这对组织形态发生有影响，这表明在某些情况下，纤连蛋白组装也可能是一种旁分泌通讯事件。
在这里，我们研究了在鸡和小鼠早期发育过程中，哪些组织表达纤连蛋白（Fn1），同时定位组装好的纤连蛋白基质，并确定主要纤连蛋白组装受体的α5和αV整合素α链的mRNA表达和/或蛋白质分布模式。我们发现有证据支持在包括未成熟间充质组织、中枢和外周神经系统成分以及发育中的肌肉在内的几种组织的纤连蛋白基质组装中存在旁分泌系统。
因此，与生长因子信号传导类似，早期发育过程中的纤连蛋白基质组装既可以是自分泌的，也可以是旁分泌的。因此，我们建议将其视为与胚胎发育过程中的生长因子信号传导处于同一水平且具有同等重要性的细胞间通讯事件。
