Abstract Background Angina with nonobstructive coronary arteries (ANOCA) is a heterogeneous condition encompassing distinct endotypes representing different underlying pathophysiological mechanisms. Despite the lack of mechanistic knowledge in these endotypes, there is broad consensus that endothelial dysfunction represents a central hallmark of ANOCA. However, studying patient-derived endothelial cells (ECs) remains challenging due to the limited availability of disease-specific endothelial samples. Purpose Here, we present a method to isolate and culture ECs from catheterization material obtained during routine diagnostic procedures. Methods and results Catheterization material was collected from 62 ANOCA patients (84% female, age 58±10 years) undergoing coronary function testing. The isolation method (Figure 1A) was successful in 40% of cases and resulted in 25 primary EC cultures that were cultured up to passage 10. Isolation success was independent of clinical or procedural characteristics. Isolated cells exhibited typical EC morphology and expressed EC markers by immunostaining (Figure 1B) and flow cytometry, and RNA sequencing confirmed their EC identity. Across passages, EC characteristics remained largely stable, although mesenchymal gene expression increased and proliferative gene programs decreased (Figure 1C). Functional assays demonstrated EC properties - wound healing, angiogenesis, activation responses and monocyte adhesion – comparable to HUVECs. However, patient-derived ECs showed higher activation in an unstimulated state and higher TNF-α-mediated monocyte adhesion under flow compared to HUVECs, indicating disease-specific functional features. Conclusion In conclusion, catheterization material can be successfully used to isolate primary ECs in approximately half of the ANOCA patients, independent of clinical characteristics. These cells express typical EC markers, maintain stable gene expression and exhibit disease-specific functional differences compared to HUVECs. Together, this novel method supports translational research into EC regulation and function and emphasizes the importance of patient-specific endothelial models in ANOCA.Figure 1.Methods and characterizationFor image description, please refer to the figure legend and surrounding text.
Jong et al. (Fri,) studied this question.