Pulmonary Vascular Platform Models the Effects of Flow and Pressure on Endothelial Dysfunction in BMPR2 Associated Pulmonary Arterial Hypertension

Abstract

Endothelial dysfunction is a known consequence of bone morphogenetic protein type II receptor (BMPR2) mutations seen in pulmonary arterial hypertension (PAH). However, standard 2D cell culture models fail to mimic the mechanical environment seen in the pulmonary vasculature. Hydrogels have emerged as promising platforms for 3D disease modeling due to their tunable physical and biochemical properties. In order to recreate the mechanical stimuli seen in the pulmonary vasculature, we have created a novel 3D hydrogel-based pulmonary vasculature model (“artificial arteriole”) that reproduces the pulsatile flow rates and pressures seen in the human lung. Using this platform, we studied both Bmpr2R899X and WT endothelial cells to better understand how the addition of oscillatory flow and physiological pressure influenced gene expression, cell morphology, and cell permeability. The addition of oscillatory flow and pressure resulted in several gene expression changes in both WT and Bmpr2R899X cells. However, for many pathways with relevance to PAH etiology, Bmpr2R899X cells responded differently when compared to the WT cells. Bmpr2R899X cells were also found not to elongate in the direction of flow, and instead remained stagnant in morphology despite mechanical stimuli. The increased permeability of the Bmpr2R899X layer was successfully reproduced in our artificial arteriole, with the addition of flow and pressure not leading to significant changes in permeability. Our artificial arteriole is the first to model many mechanical properties seen in the lung. Its tunability enables several new opportunities to study the endothelium in pulmonary vascular disease with increased control over environmental parameters.

Molecular mechanisms of right ventricular dysfunction in pulmonary arterial hypertension: focus on the coronary vasculature, sex hormones, and glucose/lipid metabolism

“…With studies now demonstrating functional and molecular analyses in both single cells and engineered heart tissue constructs (155)(156)(157), as well as other studies beginning to identify protocols to specifically differentiate RV vs. LV cardiomyocytes (158), the use of iPS derived cardiomyocyte may shed light on to primary pathologic changes that occur in the myocardium in patients with PAH without the confounding variable of afterload (40,154,159).…”

‘There and Back Again’—Forward Genetics and Reverse Phenotyping in Pulmonary Arterial Hypertension

“…PAH is characterised by molecular and cellular deviations in pulmonary vascular function [228,229], including hyperproliferation [124,129,130,149], impaired migration [127,130,150] and aberrant apoptosis [124,230]. Traditionally, research has focused on using 2D cellular monolayers for analysis of these features; however, with rapidly evolving technologies, future analysis may utilise multi-layer, 3D models such as organoids [231] and hydrogels [232] to better replicate the pathobiology of PAH.…”

BMPR2 promoter methylation and its expression in valvular heart disease complicated with pulmonary artery hypertension

“…BMPR2 mutations were found to be present in 55%−70% of high pulmonary arterial hypertension (HPH) cases and 11%−40% of idiopathic pulmonary arterial hypertension (IPH) cases [ 43 ]. BMPR2 is involved in growth, differentiation and apoptosis of epithelial and mesenchymal cells during pulmonary vascular smooth muscle hypertrophy and pulmonary vascular remodeling, which results in pulmonary hypertension [ 21 , 44 ]. DNA methylation at the promoters usually regulates expression of the target genes.…”