Modulation of ROS production in human leukocytes by ganglioside micelles
Braz. j. med. biol. res
;
43(10): 942-949, Oct. 2010. ilus
Article
Dans Anglais
| LILACS
| ID: lil-561222
ABSTRACT
Recent studies have reported that exogenous gangliosides, the sialic acid-containing glycosphingolipids, are able to modulate many cellular functions. We examined the effect of micelles of mono- and trisialoganglioside GM1 and GT1b on the production of reactive oxygen species by stimulated human polymorphonuclear neutrophils using different spectroscopic methods. The results indicated that exogenous gangliosides did not influence extracellular superoxide anion (O2.-) generation by polymorphonuclear neutrophils activated by receptor-dependent formyl-methionyl-leucyl-phenylalanine. However, when neutrophils were stimulated by receptor-bypassing phorbol 12-myristate 13-acetate (PMA), gangliosides above their critical micellar concentrations prolonged the lag time preceding the production in a concentration-dependent way, without affecting total extracellular O2.- generation detected by superoxide dismutase-inhibitable cytochrome c reduction. The effect of ganglioside GT1b (100 µM) on the increase in lag time was shown to be significant by means of both superoxide dismutase-inhibitable cytochrome c reduction assay and electron paramagnetic resonance spectroscopy (P < 0.0001 and P < 0.005, respectively). The observed phenomena can be attributed to the ability of ganglioside micelles attached to the cell surface to slow down PMA uptake, thus increasing the diffusion barrier and consequently delaying membrane events responsible for PMA-stimulated O2.- production.
Texte intégral:
Disponible
Indice:
LILAS (Amériques)
Sujet Principal:
Superoxide dismutase
/
Espèces réactives de l'oxygène
/
Ganglioside GM1
/
Gangliosides
/
Granulocytes neutrophiles
Limites du sujet:
Humains
langue:
Anglais
Texte intégral:
Braz. j. med. biol. res
Thème du journal:
Biologie
/
Médicament
Année:
2010
Type:
Article
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