Decreased VASP phosphorylation in platelets of male and female smokers of young age.

Cigarette smoking represents a major risk factor for atherosclerosis as smoking delivers huge amounts of oxidants and toxins to the human body and elicits an inflammatory response. Notably, oxidative stress and inflammation-derived oxidants are able to modulate platelet function. This is of particular interest as platelets and their activation state are implicated in the very early phases of the development of cardiovascular disease. We therefore investigated the impact of smoking on platelet reactivity and phosphorylation of vasodilator-stimulated phosphoprotein (VASP) in a group of 20 young smokers (age 25.7 ± 4.36 years; 10 male/10 female) and an age- and gender-matched control group. After overnight smoking cessation, basal and prostaglandin E1-induced phosphorylation state of intraplatelet VASP was compared between smokers and non-smokers. Furthermore, the ability of several concentrations of ADP to induce surface expression of P-selectin was assessed. Our results show that both the basal as well as prostaglandin E₁-induced phosphorylation states of VASP are significantly decreased in the smokers group. These effects can be observed in both male and female smokers to a similar extent. Furthermore, we found significantly enhanced surface expression of P-selectin in response to different concentrations of ADP in smokers; these differences are even more pronounced in the presence of prostaglandin E₁. As phosphorylated VASP represents a negative regulator of platelet activation, decreased VASP phosphorylation would be supposed to result in platelet hyperreactivity and pro-coagulant and pro-inflammatory consequences. Therefore, our findings add another piece of evidence to the harmful effects of smoking in both male and female smokers.