Subcellular Interactions during Vascular Morphogenesis in 3D Cocultures between Endothelial Cells and Fibroblasts

Abstract

Background: Increasing the complexity of in vitro systems to mimic three-dimensional tissues and the cellular interactions within them will increase the reliability of data that were previously collected with in vitro systems. In vivo vascularization is based on complex and clearly defined cell–matrix and cell–cell interactions, where the extracellular matrix (ECM) seems to play a very important role. The aim of this study was to monitor and visualize the subcellular and molecular interactions between endothelial cells (ECs), fibroblasts, and their surrounding microenvironment during vascular morphogenesis in a three-dimensional coculture model. Methods: Quantitative and qualitative analyses during the generation of a coculture tissue construct consisting of endothelial cells and fibroblasts were done using transmission electron microscopy and immunohistochemistry. Results: Dynamic interactions were found in cocultures between ECs, between fibroblasts (FBs), between ECs and FBs, and between the cells and the ECM. Microvesicles were involved in intercellular information transfer. FBs took an active and physical part in the angiogenesis process. The ECM deposited by the cells triggered endothelial angiogenic activity. Capillary-like tubular structures developed and matured. Moreover, some ECM assembled into a basement membrane (BM) having three different layers equivalent to those seen in vivo. Finally, the three-dimensional in vitro construct mirrored the topography of histological tissue sections. Conclusion: Our results visualize the importance of the physical contact between all cellular and acellular components of the cocultures.

Vascularization in tissue engineering: The architecture cues of pores in scaffolds

“…Furthermore, dynamic interaction between cells was found in the co-cultures of ECs and fibroblasts, which promoted the capillary-like tubular structures formation. 15 Although co-cultures of two or multitypes of cells gained many active results for vascularization/angiogenesis, most of the co-cultures were limited in cell culture dishes or biomaterials with size smaller than 1 cm. 16 Delivery of angiogenesis-related growth factors is another widely used strategy for promoting vascularization in tissue engineering.…”

Extracellular Vesicles-Loaded Fibrin Gel Supports Rapid Neovascularization for Dental Pulp Regeneration

“…Co-cultures of endothelial cells with supporting cells are often used to generate microvasculature and form stable networks in engineered tissue grafts [ 30 ]. Previous work by our group and others has shown that it typically takes 14 days for co-encapsulated endothelial cells and supporting cells to assemble into 3D vascular-like structures in vitro [ 31 , 32 , 33 ]. Given that direct anastomosis between the engineered microvascular network and host vasculature does not occur in dental root canals, it is impossible for implanted 3D constructs to survive long enough for vascularization, and the process must therefore be accelerated.…”

Two types of high inductive electromagnetic stimulation and their different effects on endothelial cells

“…In the second place, we prepared the endothelial cell culture based on traditional 2D in vitro culture material; more sophisticated experiments were recently published based on the use of 3D tubes, and more appropriately approximating the real geometry of the vasculature (Zargar et al 2016). In the third place, in our basic in vitro culture, we did not use any complex mix of all cell types, which are near to in vivo capillaries and veins (Kaessmeyer et al 2017). It is very likely that the inductive electromagnetic stimulation (about 50 Hz) should have double activating in vivo effects: effect on endothelial cells and an indirect effect based on the activation of keratinocytes (their activity and paracrine extracts can promote building of complex endothelial and sub-endothelial structures similar to real capillaries).…”