Mechanical regulation of vascular network formation in engineered matrices

The blood islands of the visceral yolk sac (VYS) are the initial sites of hematopoiesis in mammals. We have developed a yolk sac explant culture system to study the process of blood cell and endothelial cell development from extraembryonic mesoderm cells. No benzidine-positive cells or beta H1-globin mRNA expression was detected at the primitive streak or neural plate stage of development (E7.5). However, when isolated E7.5 dissected tissues were cultured for 36 to 72 hours in serum-free medium, hundreds of hemoglobin-producing cells and embryonic globin gene expression were identified in both intact yolk sac and VYS mesoderm explants. Explanted E7.5 extraembryonic mesoderm tissues thus recapitulate in vivo primitive erythropoiesis and do not require the presence of a vascular network or the VYS endoderm. Yolk sac blood islands also contain endothelial cells that arise by vasculogenesis and express flk-1. We detected flk-1 mRNA as early as the primitive streak stage of mouse embryogenesis. Culture of embryo proper and intact VYS explants, which contain both mesoderm and endoderm cells, produced capillary networks and expressed flk-1. In contrast, vascular networks were not seen when VYS mesoderm was cultured alone, although flk-1 expression was similar to that of intact VYS explants. The addition of vascular endothelial growth factor to VYS mesoderm explants did not induce vascular network formation. These results suggest that the VYS endoderm or its extracellular matrix is necessary for the coalescence of developing endothelial cells into capillary networks.

Download Full-text

Vascular network formation for a long-term spheroid culture by co-culturing endothelial cells and fibroblasts

2015 28th IEEE International Conference on Micro Electro Mechanical Systems (MEMS) ◽

10.1109/memsys.2015.7050995 ◽

2015 ◽

Cited By ~ 4

Author(s):

Tomoya Hayashi ◽

Hisako Takigawa-Imamura ◽

Koichi Nishiyama ◽

Hirofumi Shintaku ◽

Hidetoshi Kotera ◽

...

Keyword(s):

Endothelial Cells ◽

Network Formation ◽

Vascular Network ◽

Spheroid Culture

Download Full-text

Differences in placental capillary shear stress in fetal growth restriction may affect endothelial cell function and vascular network formation

Scientific Reports ◽

10.1038/s41598-019-46151-6 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 7

Author(s):

Win M. Tun ◽

Choon Hwai Yap ◽

Shier Nee Saw ◽

Joanna L. James ◽

Alys R. Clark

Keyword(s):

Shear Stress ◽

Endothelial Cell ◽

Fetal Growth ◽

Fetal Growth Restriction ◽

Network Formation ◽

Cell Function ◽

Vascular Network ◽

Growth Restriction ◽

Endothelial Cell Function

Download Full-text

Endothelial cell crosstalk improves browning but hinders white adipocyte maturation in 3D engineered adipose tissue

Integrative Biology ◽

10.1093/intbio/zyaa006 ◽

2020 ◽

Vol 12 (4) ◽

pp. 81-89

Author(s):

Jennifer H Hammel ◽

Evangelia Bellas

Keyword(s):

Endothelial Cells ◽

Adipose Tissue ◽

Type I Collagen ◽

Network Formation ◽

Uncoupling Protein ◽

Collagen Gel ◽

Cell Types ◽

Vascular Network ◽

Type I ◽

White Adipocyte

Abstract Central to the development of adipose tissue (AT) engineered models is the supporting vasculature. It is a key part of AT function and long-term maintenance, but the crosstalk between adipocytes and endothelial cells is not well understood. Here, we directly co-culture the two cell types at varying ratios in a 3D Type I collagen gel. Constructs were evaluated for adipocyte maturation and function and vascular network organization. Further, these constructs were treated with forskolin, a beta-adrenergic agonist, to stimulate lipolysis and browning. Adipocytes in co-cultures were found to be less mature than an adipocyte-only control, shown by smaller lipid droplets and downregulation of key adipocyte-related genes. The most extensive vascular network formation was found in the 1:1 co-culture, supported by vascular endothelial growth factor (VEGF) upregulation. After forskolin treatment, the presence of endothelial cells was shown to upregulate PPAR coactivator 1 alpha (PGC-1α) and leptin, but not uncoupling protein 1 (UCP1), suggesting a specific crosstalk that enhances early stages of browning.

Download Full-text