title: The relationship between the metabolism of sphingomyelin species and the hemolysis of sheep erythrocytes induced by Clostridium perfringens alpha-toxin.
abstract: Clostridium perfringens alpha-toxin induces the hemolysis of sheep erythrocytes by activating the metabolism of sphingomyelin (SM) via a GTP binding protein in membranes. alpha-Toxin stimulated the formation of 15-N-nervonoyl sphingosine (C24:1-ceramide), which was identified by positive ion fast atom bombardment-MS and 1H-NMR spectroscopy. C24:1-ceramide stimulated the toxin-induced hemolysis of saponin-pretreated sheep erythrocytes and increased the production of sphingosine 1-phosphate (S1P) in the cells, but N-lignoceroyl sphingosine did not. These events elicited by the toxin in the presence of C24:1-ceramide were significantly attenuated by treatment with dihydrosphingosine, a sphingosine kinase inhibitor. TLC showed that the level of C24:1-ceramide was highest among the ceramides with an unsaturated bond in the fatty acyl chain in the detergent-resistant membranes (DRMs). The toxin specifically bound to DRMs rich in cholesterol, resulting in the hydrolysis of N-nervonoic sphingomyelin (C24:1-SM) in DRMs. Treatment of the cells with pertussis toxin (PT) inhibited the alpha-toxin-induced formation of C24:1-ceramide from C24:1-SM in DRMs and hemolysis, indicating that endogenous sphingomyelinase, which hydrolyzes C24:1-SM to C24:1-ceramide, is controlled by PT-sensitive GTP binding protein in membranes. These results show that the toxin-induced metabolism of C24:1-SM to S1P in DRMs plays an important role in the toxin-induced hemolysis of sheep erythrocytes.
authors.affiliation: Department of Microbiology, Faculty of Pharmaceutical Science, Tokushima Bunri University, Tokushima, Japan.
authors.forename: Masataka
authors.initials: M
authors.lastname: Oda
authors.forename: Takayuki
authors.initials: T
authors.lastname: Matsuno
authors.forename: Ryouta
authors.initials: R
authors.lastname: Shiihara
authors.forename: Sadayuki
authors.initials: S
authors.lastname: Ochi
authors.forename: Rieko
authors.initials: R
authors.lastname: Yamauchi
authors.forename: Yuki
authors.initials: Y
authors.lastname: Saito
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Imagawa
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nagahama
authors.forename: Mugio
authors.initials: M
authors.lastname: Nishizawa
authors.forename: Jun
authors.initials: J
authors.lastname: Sakurai
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000633:toxicity*; D002135:Calcium-Binding Proteins / Q000633:toxicity*; D003902:Detergents / Q000494:pharmacology; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000502:physiology; D004912:Erythrocytes / Q000187:drug effects / Q000502:physiology*; D006461:Hemolysis; D007700:Kinetics; D012756:Sheep; D013109:Sphingomyelins / Q000378:metabolism*; D013110:Sphingosine / Q000031:analogs & derivatives / Q000494:pharmacology; D010738:Type C Phospholipases / Q000633:toxicity*
chemical_list: D001427:Bacterial Toxins; D002135:Calcium-Binding Proteins; D003902:Detergents; D013109:Sphingomyelins; D010738:Type C Phospholipases; C040649:alpha toxin, Clostridium perfringens; D013110:Sphingosine