D28-14 Novel Cell Culture Models for Hypoxia-induced Pulmonary Hypertension Research

Abstract

Hypoxia-induced pulmonary hypertension (HPH: WHO Group 3 pulmonary hypertension) is a progressive disease that is primarily caused by chronic exposure to high altitude, chronic obstructive lung disease, and obstructive sleep apnea. A rise of pulmonary vascular resistance and pulmonary arterial pressure by constant exposure to hypoxia increases right ventricular afterload, followed by right heart failure and mortality. Animal models and ex vivo tissue and/or cell culture models are indispensable to investigating the molecular mechanisms of disease progression and drug discovery. However, it has been a question about a proper cell culture model for HPH. A commonly used ex vivo model to mimic the HPH condition is exposure of cells to hypoxia (∼3% O2) in the cell culture incubator. Since increased pressure is another critical factor in HPH-induced vascular dysfunction, we developed a new device that can apply hypoxia and high pressure simultaneously. The range of mean arterial pressure that can be applied with our device is 0 - 106 mmHg with pulsatile waves. In this study, we used a pulsatile pressure of 16 ± 6 mmHg for normal pressure and 60 ± 20 mmHg as a HPH model. Human pulmonary endothelial cells were exposed to normoxia (20% O2) without any pressure (Nor), Hypoxia (3% O2) without any pressure (Hypo), normoxia with normal pressure (NorNP), and hypoxia with high pressure (HypoHiP). Forty-eight hours after exposure, RNA sequencing was conducted. We identified 3430 differentially expressed genes (DEGs) between Nor and Hypo, and 3586 DEGs between NorNP and HypoHiP. Among them, 2843 DEGs were shared in DEGs of Nor vs Hypo and NorNP vs HypoHiP. In other words, 634 DEGs were genes altered only by HypoHiP compared to NorNP; these unique genes might represent better for HPH-mediated gene alteration. We conducted pathway analysis using 634 genes, and the resulting pathways differed from those identified in the Nor vs. Hypo comparison. In summary, our newly developed device can serve as a proper ex vivo cell culture model for HPH research.

This abstract is funded by: HL146764