title: Ganglioside GT1b protects human spermatozoa from hydrogen peroxide-induced DNA and membrane damage.
abstract: We have reported previously that various gangliosides, the sialic acid containing glycosphingolipids, provide protection against sperm injury caused by reactive oxygen species (ROS). In this study, we investigated the effect of treatment of human spermatozoa with ganglioside GT1b on hydrogen peroxide (H(2)O(2))-induced DNA fragmentation and plasma membrane damage. Single-cell gel electrophoresis (Comet assay) used in the assessment of sperm DNA integrity showed that in vitro supplemented GT1b (100 microm) significantly reduced DNA damage induced by H(2)O(2) (200 microm) (p < 0.05). Measurements of Annexin V binding in combination with the propidium iodide vital dye labelling demonstrated that the spermatozoa pre-treated with GT1b exhibited a significant increase (p < 0.05) in the percentage of live cells with intact membrane and decreased phosphatidylserine translocation after exposure to H(2)O(2). Flow cytometry using the intracellular ROS-sensitive fluorescence dichlorodihydrofluorescein diacetate dye employed to investigate the transport of the extracellularly supplied H(2)O(2) into the cell interior revealed that ganglioside GT1b completely inhibited the passage of H(2)O(2) through the sperm membrane. These results suggest that ganglioside GT1b may protect human spermatozoa from H(2)O(2)-induced damage by rendering sperm membrane more hydrophobic, thus inhibiting the diffusion of H(2)O(2) across the membrane.
authors.affiliation: Department for Cell Biochemistry, Vuk Vrhovac University Clinic for Diabetes, Zagreb, Croatia. mirjana.gavella@idb.hr
authors.forename: Mirjana
authors.initials: M
authors.lastname: Gavella
authors.forename: Verica
authors.initials: V
authors.lastname: Garaj-Vrhovac
authors.forename: Vaskresenija
authors.initials: V
authors.lastname: Lipovac
authors.forename: Mariastefania
authors.initials: M
authors.lastname: Antica
authors.forename: Goran
authors.initials: G
authors.lastname: Gajski
authors.forename: Nikica
authors.initials: N
authors.lastname: Car
mesh_terms: D017304:Annexin A5 / Q000378:metabolism / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D022082:Cellular Structures / Q000378:metabolism; D020552:Comet Assay; D004247:DNA; D004249:DNA Damage; D053938:DNA Fragmentation / Q000187:drug effects; D005732:Gangliosides / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D006859:Hydrogen / Q000378:metabolism / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000378:metabolism / Q000494:pharmacology*; D008297:Male; D010545:Peroxides; D010718:Phosphatidylserines / Q000378:metabolism / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism / Q000494:pharmacology; D013094:Spermatozoa / Q000187:drug effects*
chemical_list: D017304:Annexin A5; C057755:DNA hydroperoxide; D005732:Gangliosides; D010545:Peroxides; D010718:Phosphatidylserines; D017382:Reactive Oxygen Species; C016481:trisialoganglioside GT1; D006859:Hydrogen; D004247:DNA; D006861:Hydrogen Peroxide