Highlights The endothelial cells of the pulmonary artery are a deficient model object. Our task was to work out the method of cell isolation from the Swan-Ganz catheter described in the literature. However, no cells were obtained using this technique. We have developed an alternative technique for isolating cells from blood obtained from the lumen of the pulmonary artery during right heart catheterization, and demonstrated the suitability of this technique for routine production of endothelial cell cultures from patients with pulmonary arterial hypertension. AbstractAim. Obtaining cultures of pulmonary artery endothelial cells as a model object. The endothelium ensures the integrity of the vascular wall, and disorders of endothelial function play an important role in the development of various pathological processes. Obtaining endothelial cell cultures from fragments of various human vessels is a fairly well–developed and widely used method. However, it has limitations that relate to the availability of biological material for certain groups of patients. Thus, when studying the pathogenesis of pulmonary hypertension, fragments of the pulmonary artery are practically inaccessible to the researcher, since surgical intervention for this pathology is not a routine method of treatment.Methods. The cells were obtained from the balloon of the Swan-Ganz catheter in accordance with the descriptions in the literature, alternative tissue dissociators and different adhesive media were additionally tested. The isolation of cells from the blood from the lumen of the pulmonary artery and from the peripheral (cubital) vein was carried out by dividing the blood into fractions and washing the cells of interest according to the protocols described in the literature.Results. In this work, we tested the production of pulmonary artery endothelial cells in patients with pulmonary arterial hypertension by removing cells from the balloon of the Swan-Ganz catheter during right heart catheterization. The catheter removal method has shown its unsuitability for use in routine laboratory practice. As an alternative, we have developed a method for obtaining endothelial cells from blood taken from the lumen of the pulmonary artery during catheterization.Conclusion. Isolation of endothelial cells from blood taken from the lumen of the pulmonary artery during right heart catheterization showed the suitability of this method for routine production of endothelial cell cultures from patients with pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is characterized by progressive vascular remodeling and immune dysregulation. Myeloid angiogenic cells (MACs) are blood-derived mononuclear cells that acquire endothelial-like features at sites of vascular injury, but their transcriptomic phenotype in the pulmonary vascular compartment is poorly characterized. We isolated adherent cells from blood aspirated from the wedged pulmonary artery of four patients with severe PAH during right heart catheterization. The cells were vWF-positive and ACTA2-negative by immunocytochemistry and co-expressed canonical endothelial (CDH5, PECAM1, ERG, FLT1) and myeloid (PTPRC/CD45, CD14, SPI1, IRF8) transcripts, consistent with MAC-like adherent cultures rather than a conventional endothelial population. Bulk RNA sequencing of these cultures was compared with human pulmonary artery endothelial cells (HPAECs) and HUVECs used as endothelial reference cultures. Relative to both references, PAH MACs showed higher transcript levels of cytokines (IL1A, TNF, IL15, IL10) and matrix metalloproteinases (MMP8/9/12); relative to HPAECs, they showed lower levels of Notch-associated genes (DLL4, HEYL). Protein–protein interaction analysis identified modules centered on complement components, myeloid immune receptors and CC chemokines. Because MACs from non-PAH subjects were not available, these differences describe the phenotype of PAH-derived MACs relative to endothelial reference cells rather than a PAH-specific effect. Adherent cultures obtained from wedged pulmonary arterial blood are therefore dominated by a mononuclear phagocyte transcriptional program, which has direct implications for the design of patient-derived pulmonary vascular cell models.