Neural crest cell-autonomous roles of fibronectin in cardiovascular development

Abstract

The chemical and mechanical properties of extracellular matrices (ECMs) modulate diverse aspects of cellular fates; however, how regional heterogeneity in ECM composition regulates developmental programs is not well understood. We discovered that fibronectin 1 (Fn1) is expressed in strikingly non-uniform patterns during mouse development, suggesting that regionalized synthesis of the ECM plays cell-specific regulatory roles during embryogenesis. To test this hypothesis, we ablated Fn1 in the neural crest (NC), a population of multi-potent progenitors expressing high levels of Fn1. We found that Fn1 synthesized by the NC mediated morphogenesis of the aortic arch artery and differentiation of NC cells into vascular smooth muscle cells (VSMCs) by regulating Notch signaling. We show that NC Fn1 signals in an NC cell-autonomous manner through integrin α5β1 expressed by the NC, leading to activation of Notch and differentiation of VSMCs. Our data demonstrate an essential role of the localized synthesis of Fn1 in cardiovascular development and spatial regulation of Notch signaling.

Hyperacetylation of Microtubules in Mesenchymal Cells Increases Cytokeratin 14–Positive Epithelial Progenitors in Developing Salivary Glands

“…2D). Last, a recent publication reports that increased FN can induce Notch signaling via integrins (Wang and Astrof 2016). Together, these findings support a model in which hyperacetylation of microtubules in the mesenchyme of salivary glands increases FN and α5β1 integrins, which in turn increases TGFβ and Notch signaling, which together decrease epithelial branching morphogenesis.…”

Collaboration of fibronectin matrix with other extracellular signals in morphogenesis and differentiation

“…Interestingly, activation of Notch was limited to those neural crest cells that express FN and α5β1 and Notch activation was needed for VSMC differentiation by neural crest. These findings suggest the novel idea that FN induces an autocrine signaling response by cells [19]*. Future interpretations of FN’s effects should consider potentially distinct roles of paracrine and autocrine mechanisms of FN action.…”

“…Together these analyses of cardiac neural crest differentiation demonstrate a central role for integrins and their FN matrix in controlling cell differentiation by providing pericellular signals from the ECM itself as well as by presenting exogenous factors like TGFβ. Other FN-dependent signals may participate in development of a VSMC-phenotype [18,19]. Interestingly, activation of Notch was limited to those neural crest cells that express FN and α5β1 and Notch activation was needed for VSMC differentiation by neural crest.…”

Isolation of Mouse Cardiac Neural Crest Cells and Their Differentiation into Smooth Muscle Cells

“…To identify neural crest-derived cells, we isolated neural crest cells from embryos resulting from the following cross: Fn1 flox/flox ;ROSA mTmG/mTmG female mice x Fn1 +/− ;Tfap2α IRESCre/+ male mice. In 50% of the progeny from this cross, neural crest cells are lineage-labeled by the expression of GFP, so we could easily identify neural crest cells by their GFP expression without the need for cell sorting (Wang and Astrof, 2016). Additional Cre-expressing strains that can be used are Wnt1-Cre2 (Lewis et al.…”

“…We have shown that fibronectin (Fn1) plays an important role in the development of the CNCC by regulating the differentiation of CNCCs into vascular smooth muscle cells around pharyngeal arch arteries (Wang and Astrof, 2016). This protocol describes the isolation of CNCCs from the neural tube and from the caudal pharyngeal arches, and the differentiation of neural crest-derived cells into smooth muscle cells.…”