Nicotine's impact on platelet function: insights into hemostasis mechanisms

Area of Science:

• Pharmacology
• Hematology
• Biochemistry

Background:

• Traditional medicines have utilized tobacco, rich in nicotine, for hemostasis in traumatic injuries.
• Nicotine's pro-aggregatory effects on platelets are known, but its broader impact on platelet function and mechanisms are not fully understood.

Purpose of the Study:

• To comprehensively investigate the functional effects of nicotine on human platelets.
• To elucidate the pharmacological mechanisms underlying nicotine's influence on platelet activation and coagulation.

Main Methods:

• Thromboelastography was used to assess nicotine's impact on platelet function during coagulation.
• Platelet aggregation, granule release, adhesion, spreading, and contraction assays were performed.
• Molecular docking identified potential platelet receptors, followed by inhibitor studies and analysis of downstream signaling pathways (PI3K, AKT, ERK1/2).

Main Results:

• Nicotine fully activated washed human platelets, promoting aggregation, granule release, adhesion, spreading, and contraction.
• Nicotine enhanced intracellular calcium ion concentration ([Ca2+]i) in platelets.
• Nicotine's effects were mediated through the PAR4 receptor, leading to PI3K, AKT, and ERK1/2 phosphorylation and subsequent αIIbβ3 receptor activation.

Conclusions:

• Nicotine activates αIIbβ3 receptors via the PAR4 receptor signaling pathway, significantly enhancing platelet function.
• These findings suggest nicotine's potential as a novel hemostatic agent.