P 018 - Free radical pathway of 2-hexadecenal formation in cells and its biological role

Abstract

In our earlier studies it has been established that the action of gamma-, UV-irradiation and HOCl on aqueous deaerated sphingolipids dispersions causes destruction of studied biomolecules with the formation of 2-hexadecenal. HOCl has powerful cytotoxic properties because it is a strong oxidizer and a source of reactive chlorine species. We investigated the effect of HOCl on human erythrocytes, HEK293 and astroglial cells. For the sensitive quantitative analysis of 2-hexadecenal in cells we used extraction procedure and applied the method based on HPLC with fluorescence detector. We found that the HOCl-treatment of cells at concentrations from 10 µM to 1 mM provokes 2-hexadecenal formation. It has been found that 2-hexadecenal at micromolar concentrations regulates reactive oxygen species generation in human peripheral blood neutrophils stimulated by adhesion and fMLP, through reallocation of myeloperoxidase, phospholipase A2, cyclooxygenase and 5-lipoxygenase contributions to this process. 2-Hexadecenal modifies the functions of astroglial cells in culture by changing their morphological characteristics. This is associated with the redistribution of F-actin and the subsequent cytoskeleton reorganization. It results in cells’ mitotic and proliferative activity reduction through the initiation of apoptosis involving JNK and p38 mitogen-activated protein kinase pathways.