Pseudomonas aeruginosa quorum sensing molecule N-3-oxo-dodecanoyl-l-homoserine lactone activates human platelets through intracellular calcium-mediated ROS generation

Pseudomonas aeruginosa, an opportunistic pathogen release N-3-oxo-dodecanoyl-l-homoserine lactone (3-oxo-C₁₂HSL) and N-butyryl-l-homoserine lactone (C₄-HSL) quorum sensing (QS) molecules to regulate various virulence factors responsible for infection in the host. 3-oxo-C₁₂ HSL not only regulates the bacterial gene expression but also modulates the host cell system. Thus, it is pertinent to evaluate the effect of these QS molecules on blood platelets which is responsible for the maintenance of hemostasis and thrombus formation. Here, in the present study, we showed that 3-oxo-C₁₂ HSL activates platelets in a dose-dependent manner and induces intracellular calcium-mediated reactive oxygen species (ROS) release, whereas no such effect was observed with C₄-HSL. 3-oxo-C₁₂ HSL stimulated ROS release was mediated by NADPH oxidase. Results confirmed the involvement of phospholipase C (PLC) and IP₃ receptor behind intracellular calcium-mediated ROS generation. The impact of 3-oxo-C₁₂ HSL on platelet activation suggests that it could interfere and alter the normal function of platelet in individuals infected with P. aeruginosa.