Pulmonary In Vitro Perfusion (PIPE) Model to Study Cellular Crosstalk in Neonatal Pulmonary Vascular Disease

Abstract

Bronchopulmonary dysplasia (BPD) is a chronic pulmonary disorder arising from shear stress and oxygen exposure resulting in the development of pulmonary vascular disease (PVD) in a rarefied vascular bed. Cellular crosstalk between the injured endothelial (EC) and proliferating smooth muscle cells (SMC) with the circulating immune cells and its impact on extracellular matrix (ECM) remodeling awaits characterization due to the lack of suitable in vitro models mimicking PVD in BPD. We herewith introduce a novel, human-based Pulmonary In Vitro Perfusion (PIPE) model to recapitulate pathophysiologic changes in BPD, by i) leveraging a triple co-culture with human primary vascular SMCs as well as human ECs (EA.hy926) and monocytic (THP1) cells, ii) applying physiologic and non-physiologic shear stress in the presence or absence of hyperoxia (21%, 40%, 80% O2), and iii) visualizing immune cell circulation and transmigration. We demonstrate a significant contribution of non-physiologic shear stress (21 dyne/cm2) and O2 on endothelial barrier formation, nitric oxide, and inflammatory cytokines secretion (IL8, IL6, IL1b, and CCL2). We observed subsequent transmigration of THP1 cells across the EC barrier towards the SMC layer together with ECM remodeling. The novel PIPE model thereby proves as a biomimetic platform to establish the main characteristics of PVD in vitro that will next be used to confirm the role of circulating markers of EC damage and inflammation in preterm infants suffering from the disease, thereby providing new insight into therapeutic targets to reverse vascular pathology.