Rapid killing of human neutrophils by the potent activator phorbol 12-myristate 13-acetate (PMA) accompanied by changes different from typical apoptosis or necrosis

Abstract

To elucidate the relationship between activation of neutrophils and their subsequent death, the effect of phorbol 12-myristate 13-acetate (PMA), a potent activator of neutrophils, was examined. PMA-treated neutrophils showed morphological changes quite different from those of typical apoptosis or necrosis. After fusion of the lobate nucleus, nuclear contents of chromatin uniformly decreased in compactness and soon after the nuclear envelope was broken. Even at this stage, cytoplasmic organelles did not undergo degeneration. Membrane permeability began increasing at 3 h of incubation with PMA, subsequent to nuclear change. Conventional agarose gel electrophoresis and pulsed field gel electrophoresis of DNA from PMA-treated neutrophils revealed no DNA degradation products smaller than 300 kbp. PKC inhibitors, staurosporine and H-7, prevented cytotoxicity by PMA. Furthermore, antioxidants, thiourea, dimethylthiourea, pyrrolidinethiocarbamate, and N-acetyl-L-cysteine, but not superoxide dismutase, were also active in preventing PMA cytotoxicity, suggesting that cell suicide resulting from PMA treatment is due to oxygen radicals, especially the hydroxyl radical. A certain population of neutrophils phagocytosing opsonized zymosan also showed changes similar to those observed in PMA-treated cells.

NADPH Oxidase-dependent Oxidation and Externalization of Phosphatidylserine during Apoptosis in Me2SO-differentiated HL-60 Cells

“…In fact, we observed that superoxide production was completely blocked by staurosporine in Me 2 SO-differentiated HL-60 cells stimulated by PMA. These findings concur with the previous observation that staurosporine prevents PMA-induced cytotoxicity in neutrophils (34). Thus, staurosporine is able to prevent NADPH oxidase-dependent oxidative stress and subsequent oxidantinduced apoptosis in Me 2 SO-differentiated HL-60 cells.…”

Flow cytometric quantitative determination of ingestion by phagocytes needs the distinguishing of overlapping populations of binding and ingesting cells

“…In those cases, a decreased TOT(inside) value may arise from TB quenching because the neutrophils' cell surface might become permeable as a consequence of uncontrolled cell death letting vital dyes, such as TB, through the membrane. There is evidence that uncontrolled cell death can be a consequence of increased intracellular production of oxygen radicals induced by phorbol 12-myristate 13-acetate or zymosan (37). In addition, extracellular oxygen radicals, whose concentration can increase quite high, may be able to damage the cell membrane.…”

Stem bark and flower extracts ofVismia caulifloraare highly effective antioxidants to human blood cells by preventing oxidative burst in neutrophils and oxidative damage in erythrocytes

“…PMA was used as neutrophil stimulator because its effect is closely analogous to that obtained during the phagocytic process with an activation of protein kinase C, which results in NADPH oxidase activation, with subsequent production of reactive species (Takei et al, 1996). The luminol probe reacts unspecifically with ROS and RNS (O , and therefore may be considered a useful tool to evaluate the Table 1.…”