Proteomics Analysis Reveals Diverse Molecular Characteristics between Endocardial and Aortic-Valvular Endothelium

Abstract

The variations in the protein profile of aortic-valvular (AVE) and endocardial endothelial (EE) cells are currently unknown. The current study’s objective is to identify differentially expressed proteins and associated pathways in both the endothelial cells. We used endothelial cells isolated from the porcine (Sus scrofa) aortic valve and endocardium for the profiling of proteins. Label-free proteomics was performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Our proteomics analysis revealed that 29 proteins were highly expressed, and 25 proteins were less expressed in the valve than the endocardial endothelium. The cell surface markers, such as CD63, ICAM1, PECAM1, PROCR, and TFRC, were highly expressed in EE. In contrast, CD44 was highly expressed in AVE. The pathway analysis showed that metabolic process-related proteins and extracellular matrix-related proteins were enriched in valves. Differential enrichment of signaling pathways was observed in the endocardium. The hemostasis function-related proteins were increased in both endothelial cells. The proteins and pathways enriched in aortic-valvular and endocardial endothelial cells revealed the distinct phenotype of these two closely related cells.

Isolation and Characterization of Porcine Endocardial Endothelial Cells

“…34 While aortic endothelial cells are commercially available and easy to obtain, recent studies have found that EECs have a unique proteomic signature, even in comparison to aortic endothelial cells, further demonstrating the necessity of including EECs in cardiac disease models. 6,14 This study also showed that EECs display the classical endothelial phenotypic characteristics, and that this phenotype is stable up to at least passage 15. EECs stained positively for typical markers of endothelial cells, but they were smaller and had a more elongated morphology than reported for other common endothelial cell lines.…”

“…34 While aortic endothelial cells are commercially available and easy to obtain, recent studies have found that EECs have a unique proteomic signature, even in comparison to aortic endothelial cells, further demonstrating the necessity of including EECs in cardiac disease models. 6,14…”

“…For example, valvular endothelial cells cover the surface of the aortic, mitral, pulmonary, and tricuspid valves within the heart and are exposed to a high volume of circulating blood and mechanical forces during the cardiac cycle, whereas cardiac lymphatic endothelial cells are dispersed throughout the myocardium to drain fluids from the tissue and sprout vessels in response to injury (1,3). It has even been demonstrated that valvular endothelial cells on opposing sides of the aortic valve have different phenotypic signatures that can be detected (6). Studies have shown that endothelial cells profoundly shift their behavior, morphology, and cellular signaling in response to pathological environments (4).…”

“…1,3 It has even been demonstrated that valvular endothelial cells on opposing sides of the aortic valve have different phenotypic signatures that can be detected. 6 Furthermore, endothelial cells can profoundly shift their behavior, morphology, and cellular signaling in response to pathological environments. 4 Since endothelial phenotype varies depending on location, and these variations may impact responses to pathological environments, the inclusion of region-specific endothelial cells in disease models can enhance understanding of the disease and increase understanding of disease mechanisms on the cellular level.…”

Proteomic profiling spotlights the molecular targets and the impact of the natural antivirulent umbelliferone on stress response, virulence factors, and the quorum sensing network of Pseudomonas aeruginosa

“…Relative protein quantification of control and treated samples was performed using ESI-nano LC-MS/MS analysis [a nano ACQUITY UPLC ® chromatographic system (Waters) coupled with a Quadrupole Time-of-Flight (Q-TOF) mass spectrometer (SYNAPT-G2, Waters)] as described by Aneesh Kumar et al. (2021) .…”