A Pulmonary Vascular Model From Endothelialized Whole Organ Scaffolds.

Yifan Yuan,Allison M Greaney,Pavlina Baevova,Tomohiro Obata,Naftali Kaminski,Juan Wang,Jonas C Schupp,Laura E Niklason,Alexander J Engler,Katherine L Leiby,Mehmet H Kural,Mervin C Yoder,Micha Sam Brickman Raredon,Taylor S Adams,Hong Qian

doi:10.3389/fbioe.2021.760309

Yifan Yuan, Allison M Greaney + Show 13 more

Open Access

https://doi.org/10.3389/fbioe.2021.760309

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Abstract

The development of an in vitro system for the study of lung vascular disease is critical to understanding human pathologies. Conventional culture systems fail to fully recapitulate native microenvironmental conditions and are typically limited in their ability to represent human pathophysiology for the study of disease and drug mechanisms. Whole organ decellularization provides a means to developing a construct that recapitulates structural, mechanical, and biological features of a complete vascular structure. Here, we developed a culture protocol to improve endothelial cell coverage in whole lung scaffolds and used single-cell RNA-sequencing analysis to explore the impact of decellularized whole lung scaffolds on endothelial phenotypes and functions in a biomimetic bioreactor system. Intriguingly, we found that the phenotype and functional signals of primary pulmonary microvascular revert back—at least partially—toward native lung endothelium. Additionally, human induced pluripotent stem cell-derived endothelium cultured in decellularized lung systems start to gain various native human endothelial phenotypes. Vascular barrier function was partially restored, while small capillaries remained patent in endothelial cell-repopulated lungs. To evaluate the ability of the engineered endothelium to modulate permeability in response to exogenous stimuli, lipopolysaccharide (LPS) was introduced into repopulated lungs to simulate acute lung injury. After LPS treatment, proinflammatory signals were significantly increased and the vascular barrier was impaired. Taken together, these results demonstrate a novel platform that recapitulates some pulmonary microvascular functions and phenotypes at a whole organ level. This development may help pave the way for using the whole organ engineering approach to model vascular diseases.

Highlights

Diseases of the lung vasculature, including primary pulmonary hypertension, capillary leak syndrome/acute respiratory distress syndrome (ARDS), inhalation injury, and the novel coronavirus disease-19 (COVID-19), are difficult to study in vitro due to the lack of functional ex vivo models (Huertas et al, 2018; Ackermann et al, 2020)
Leveraging single-cell RNA-sequencing analysis, we investigated the role of acellular whole lung scaffolds in regulating endothelial phenotypes and functions in a biomimetic bioreactor system
We found that both primary and iPSC-derived endothelium could create a degree of barrier function in lung scaffolds, and they partially gain native lung endothelial phenotypes

Summary

Introduction

Diseases of the lung vasculature, including primary pulmonary hypertension, capillary leak syndrome/acute respiratory distress syndrome (ARDS), inhalation injury, and the novel coronavirus disease-19 (COVID-19), are difficult to study in vitro due to the lack of functional ex vivo models (Huertas et al, 2018; Ackermann et al, 2020). Organoid and microfluidics-based in vitro culture systems have emerged as tools for modeling vascular diseases (Tsai et al, 2012; Qiu et al, 2018; Wimmer et al, 2019; Monteil et al, 2020) These systems typically involve culturing differentiated or mature endothelial cells in polydimethylsiloxane (PDMS) or hydrogel-based structures under some degree of perfusion (Tsai et al, 2012; Qiu et al, 2018; Wimmer et al, 2019). No in vitro platform exists that can simulate native pulmonary vascular phenotypes and functions for long time periods and in a controlled fashion

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