In vitro models and approaches to study underlying pathways of pulmonary arterial hypertension: a review

Pulmonary arterial hypertension (PAH) is a deadly disease, and the pathophysiology is complex, with myriad cellular pathways contributing. Currently, there is a lack of studies and no review paper that serves as a resource to guide researchers on potential cell or cell culture models for studying isolated aspects or mechanisms of PAH disease. Therefore, this review paper aims to achieve this, and we highlight the usefulness or pros and cons of several in vitro approaches. This includes the use of pulmonary artery endothelial cells, inducible pluripotent stem cell-derived endothelial cells, circulating endothelial cells, human umbilical vein endothelial cells, endothelial colony-forming cells, pulmonary artery smooth muscle cells, fibroblasts, mesenchymal stem cells, rat cardiomyoblasts or cardiomyocytes, platelets and peripheral blood mononuclear cells isolated from whole blood, lung organoids and co-culture approaches. However, it is essential to be mindful that each has its pros and cons, and caution should be exercised when drawing inferences from findings or attempting to extrapolate them to a clinical setting.