Differential modulation of endothelial cell function by fresh frozen plasma

Area of Science:

• Endothelial biology
• Vascular physiology
• Immunology

Background:

• Fresh frozen plasma (FFP) shows promise in improving endothelial properties and vascular barrier function in vivo, particularly in sepsis and major surgery models.
• However, the precise in vitro effects and underlying mechanisms of FFP on endothelial cells remain incompletely understood.

Purpose of the Study:

• To investigate the in vitro effects of FFP on key endothelial cell functions.
• To elucidate the molecular mechanisms by which FFP modulates endothelial responses.

Main Methods:

• Human pulmonary microvascular endothelial cells (HPMECs) were stimulated with LPS and then treated with FFP.
• Assessed were endothelial permeability, intercellular gap formation, NF-κB translocation, gene expression (IL-8, ICAM-1, VCAM-1, VEGF, ANG-2), monocyte adhesion, intracellular cAMP levels, and protein phosphorylation.
• Syndecan-1 serum levels were measured in surgical patients before and after FFP transfusion.

Main Results:

• FFP increased intracellular cAMP levels, counteracting LPS-induced decreases.
• This led to reduced upregulation of inflammatory and leakage-related genes (IL-8, ICAM-1, VCAM-1, VEGF, ANG-2) and restored endothelial barrier function and protein phosphorylation.
• Conversely, FFP enhanced LPS-induced NF-κB nuclear translocation and monocyte adhesion.
• Post-transfusion Syndecan-1 levels were lower in FFP-treated surgical patients.

Conclusions:

• FFP exhibits a dual effect on endothelial cells, improving barrier function while also promoting inflammatory responses.
• These differential effects may be mediated by FFP's ability to increase intracellular cAMP levels.
• Findings highlight the complex impact of FFP on endothelial properties, with implications for clinical applications.