- Turkish Journal of Biology
- Vol: 41 Issue: 1
- Tumor necrosis factor-alpha induced caspase-3 activation-related iNOS gene expression in ADP-activat...
Tumor necrosis factor-alpha induced caspase-3 activation-related iNOS gene expression in ADP-activated platelets
Authors : Özge Çevik, Zelal Adigüzel, Ahmet Tarik Baykal, Azize Şener
Pages : 31-40
View : 13 | Download : 6
Publication Date : 9999-12-31
Article Type : Makaleler
Abstract :Platelets are sensitive cells and are easily activated by different stimulants in the circulation system. It is known that tumor necrosis factor-alpha (TNF-α) is a proinflammatory cytokine and plays a role in inflammation. The role of TNF-α in the apoptotic process in blood platelets is unknown. In order to study the formation of apoptosis in platelets after incubation with TNF-α and/or ADP, several biomarkers were chosen: phosphatidylserine (PS) exposure and P-selectin binding; cGMP, Cyt-c, and Ca2+ levels and NOS activation; and gene and protein expression of caspase-3 and iNOS. Platelets were incubated with 100 pg/mL TNF-α and/or 50 mM iNOS specific inhibitor, such as at 1400 W for 1 h at 37 °C in the presence of 5 µM ADP. According to the results, the levels of PS exposure and P-selectin binding were significantly higher in TNF-α + ADP platelets, which decreased with the addition of 1400 W. A significant induction in cGMP, Cyt-c, and Ca2+ levels was observed in platelets treated with TNF-α + ADP. On the other hand, the upregulation of the apoptotic gene caspase-3 and iNOS expression levels in TNF-α-treated and ADP-activated platelets was significantly reversed with the addition of 1400 W. These data demonstrate that TNF-α promotes iNOS expression through caspase-3 stimulation in human platelets, and its concomitance leads to the triggering of apoptosis-mediated inflammation upon platelet activation.Keywords : Platelets, apoptosis, TNF-α, iNOS, caspase-3