Cell force-mediated matrix reorganization underlies multicellular network assembly

Christopher D Davidson,Ina Zaimi,William Y Wang,Danica Kristen P Jayco,Brendon M Baker

doi:10.1038/s41598-018-37044-1

Christopher D Davidson, Ina Zaimi + Show 3 more

Open Access

https://doi.org/10.1038/s41598-018-37044-1

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Journal: Scientific Reports	Publication Date: Jan 9, 2019
Citations: 92	License type: open-access

Affiliation: University of Michigan–Ann Arbor

Abstract

Vasculogenesis is the de novo formation of a vascular network from individual endothelial progenitor cells occurring during embryonic development, organogenesis, and adult neovascularization. Vasculogenesis can be mimicked and studied in vitro using network formation assays, in which endothelial cells (ECs) spontaneously form capillary-like structures when seeded in the appropriate microenvironment. While the biochemical regulators of network formation have been well studied using these assays, the role of mechanical and topographical properties of the extracellular matrix (ECM) is less understood. Here, we utilized both natural and synthetic fibrous materials to better understand how physical attributes of the ECM influence the assembly of EC networks. Our results reveal that active cell-mediated matrix recruitment through actomyosin force generation occurs concurrently with network formation on Matrigel, a reconstituted basement membrane matrix regularly used to promote EC networks, and on synthetic matrices composed of electrospun dextran methacrylate (DexMA) fibers. Furthermore, modulating physical attributes of DexMA matrices that impair matrix recruitment consequently inhibited the formation of cellular networks. These results suggest an iterative process in which dynamic cell-induced changes to the physical microenvironment reciprocally modulate cell behavior to guide the formation and stabilization of multicellular networks.

Highlights

Vasculogenesis, the de novo formation of blood vessels, occurs during embryonic development, organogenesis, and adult neovascularization[1,2,3]
Many of the settings commonly used to promote the formation of endothelial cells (ECs) networks in vitro – Matrigel, collagen, and fibrin – possess fibrous structure at various length scales with complex and hierarchical mechanics not fully encapsulated by an elastic modulus value[21,22,23,24]
We established a model of EC network formation in a synthetic fibrous matrix, orthogonally examined the effect of matrix architecture and mechanics on this assembly process, and found that cell-force mediated matrix reorganization and continued force propagation is required for the formation and stabilization of these networks

Summary

Introduction

Vasculogenesis, the de novo formation of blood vessels, occurs during embryonic development, organogenesis, and adult neovascularization[1,2,3]. Endothelial cells (ECs) plated on Matrigel (a reconstituted gel containing basement membrane matrix proteins) rapidly attach, extend, and form networks of multicellular capillary-like tubules within 24 hours[5]. These and similar studies performed with two- or three-dimensional collagen and fibrin gels[6,7] have been critical in determining the vital growth factors[8], genes[9], and signaling pathways[10] required for vasculogenesis, but far less is known about how physical attributes of the extracellular matrix (ECM) govern this cell assembly process. We established a model of EC network formation in a synthetic fibrous matrix, orthogonally examined the effect of matrix architecture and mechanics on this assembly process, and found that cell-force mediated matrix reorganization and continued force propagation is required for the formation and stabilization of these networks

Methods

Results

Conclusion