Microfluidic culture platform combined with transcriptomic profiling reveals molecular signatures that promote 3D vascular network growth and maturation
Sin Yen Tan1, Ziuwin Leung2, Angela Ruohao Wu1,2
1 Department of Chemical and Biological Engineering, School of Engineering
2 Division of Life Science, School of Science
Hong Kong University of Science and Technology
Hong Kong S.A.R, China
angelawu@ust.hk
Abstract
Compared to conventional flask- or well-based culture systems, microfluidic cell culture platforms are a highly controllable and tunable microenvironment for 3D cell cultures, enabling researchers to create precise experimental perturbations that lead to deeper understanding of biological mechanisms. With recent technological and biological advancements in creating more and more physiologically relevant organ-on-chip models, the need is also emerging for the creation of more sophisticated 3D microfluidic vasculature-on-chip culture. Current on-chip vascular culture often does not reach maturity as in-vivo vasculature does; on-chip vessels also often regress and die within 1-2 weeks, making long term experiments challenging and unpredictable. Co-culture with fibroblasts can improve on-chip vascular cultures in promoting maturation and substantially increasing survival time, but it is unclear how the fibroblasts and vascular endothelial cells interact, and whether further improvements could be made to more closely mimic in-vivo conditions. We establish vascular endothelial cells in monoculture and in co-cultures with fibroblasts in microfluidic devices and allow them to grow on-chip. We then extract the cells from the device at different time points and perform RNA sequencing to profile the gene expression of each cell type, in order to compare the difference in their molecular signatures with and without fibroblast co-culture over time. By combining microfluidic platform technology with transcriptomic profiling techniques in this systems biology approach, we identified ligand-receptor pairs that are up- or down-regulated over the course of endothelial cell self-assembly and vascular maturation, revealing key pathways in the endothelial cells that appear regulated by paracrine signaling from the fibroblasts. We also identified factors secreted by fibroblasts that appear intended for crosstalk with immune cells, which are currently absent from the microfluidic system. This suggests that addition of immune cells to the on-chip culture system could be an important next step to generate more physiologically relevant vascular cultures in-vitro.
Short Bio
Angela Ruohao Wu is an assistant professor in the Division of Life Science and the Department of Chemical and Biological Engineering at The Hong Kong University of Science and Technology. Angela obtained her B.S. in Bioengineering from the University of California, Berkeley, her M.S. and Ph.D. degrees in Bioengineering from Stanford University, and her post-doctoral work also at Stanford University. In 2015, Angela co-founded Agenovir Corporation, a CRISPR-based therapeutics company targeting infectious diseases for a complete cure. Her research group is passionate about the development of new microfluidics and genomics technologies at the interface of basic biology and engineering, and using these interdisciplinary approaches to investigate biological mechanisms and human diseases. As recognition of her achievements in technology and innovation, Angela was named one of MIT Technology Review Innovators under 35 Asia in 2016, and a World Economic Forum Young Scientist in 2018.