Effect of 4-hydroxynonenal, a lipid peroxidation product, on exocytosis in HL-60 cells.

Our work analysed the effect of 4-hydroxynonenal (HNE), a chemotactic aldehydic end-product of lipid peroxidation, on exocytosis in HL-60 cells. We measured the release of beta-glucuronidase, an enzyme of azurophil granules, from the cells incubated at 37 degrees C for 10 min in the presence of HNE concentrations ranging between 10(-8) and 10(-5) M. The release of lactate dehydrogenase was assayed to test cell viability. HNE (1 microM) was able to induce a significant and strong stimulation of beta-glucuronidase secretion without leading to cytotoxic effects. The finding that HNE could increase the exocytotic secretion from HL-60 cells together with its known chemotactic property supports the hypothesis that this lipid peroxidation product may play an important role as a chemical mediator of inflammation; moreover it is noteworthy that micromolar concentrations of HNE have actually been found in exudates from acute and chronic inflammations.