title: Astaxanthin Improves Human Sperm Capacitation by Inducing Lyn Displacement and Activation.
abstract: Astaxanthin (Asta), a photo-protective red pigment of the carotenoid family, is known for its multiple beneficial properties. In this study, the effects of Asta on isolated human sperm were evaluated. Capacitation involves a series of transformations to let sperm acquire the correct features for potential oocyte fertilization, including the generation of a controlled amount of reactive oxygen species (ROS), cholesterol depletion of the sperm outer membrane, and protein tyrosine phosphorylation (Tyr-P) process in the head region. Volunteers, with normal spermiogram values, were divided in two separate groups on the basis of their ability to generate the correct content of endogenous ROS. Both patient group (PG) and control group (CG) were analysed for Tyr-phosphorylation (Tyr-P) pattern and percentages of acrosome-reacted cells (ARC) and non-viable cells (NVC), in the presence or absence of Asta. In addition, the involvement of ROS on membrane reorganization and the presence of Lyn, a Src family kinase associated with lipid rafts, were investigated. Results show that Lyn is present in the membranes of human sperm, mainly confined in midpiece in resting conditions. Following capacitation, Lyn translocated to the head concomitantly with raft relocation, thus allowing the Tyr-P of head proteins. Asta succeeded to trigger Lyn translocation in PG sperm thus bypassing the impaired ROS-related mechanism for rafts and Lyn translocation. In this study, we showed an interdependence between ROS generation and lipid rafts and Lyn relocation leading the cells to undergo the successive acrosome reaction (AR). Asta, by ameliorating PG sperm functioning, may be utilised to decrease male idiopathic infertility.
authors: Department of Women's and Chilren's Health, University of Padova, Padova 35100, Italy. alessandra.andrisani@unipd.it.
authors: Alessandra
authors: A
authors: Andrisani
authors: Department of Molecular Medicine-Biological Chemistry, University of Padova, Padova 35129, Italy. gabriella.dona@unipd.it.
authors: Gabriella
authors: G
authors: Donà
authors: Department of Molecular Medicine-Biological Chemistry, University of Padova, Padova 35129, Italy. elena.tibaldi@unipd.it.
authors: Elena
authors: E
authors: Tibaldi
authors: Department of Molecular Medicine-Biological Chemistry, University of Padova, Padova 35129, Italy. annamaria.brunati@unipd.it.
authors: Anna Maria
authors: AM
authors: Brunati
authors: Department of Medicine-Endocrinology, University of Padova, Padova 35100, Italy. ChiaraSabbadin@libero.it.
authors: Chiara
authors: C
authors: Sabbadin
authors: Department of Medicine-Endocrinology, University of Padova, Padova 35100, Italy. decio.armanini@unipd.it.
authors: Decio
authors: D
authors: Armanini
authors: Department of Molecular Medicine-Microbiology Section, University of Padova, Padova 35129, Italy. gualtiero.alvisi@unipd.it.
authors: Gualtiero
authors: G
authors: Alvisi
authors: Department of Women's and Chilren's Health, University of Padova, Padova 35100, Italy. salvatore.gizzo@gmail.com.
authors: Salvatore
authors: S
authors: Gizzo
authors: Department of Women's and Chilren's Health, University of Padova, Padova 35100, Italy. guido.ambrosini@unipd.it.
authors: Guido
authors: G
authors: Ambrosini
authors: Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova 35129, Italy. eugenio.ragazzi@unipd.it.
authors: Eugenio
authors: E
authors: Ragazzi
authors: Department of Molecular Medicine-Biological Chemistry, University of Padova, Padova 35129, Italy. luciana.bordin@unipd.it.
authors: Luciana
authors: L
authors: Bordin
mesh_terms: D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D008297:Male; D021962:Membrane Microdomains / Q000187:drug effects* / Q000502:physiology; D021381:Protein Transport / Q000187:drug effects / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism; D013075:Sperm Capacitation / Q000187:drug effects*; D013094:Spermatozoa / Q000187:drug effects* / Q000502:physiology; D024341:Xanthophylls / Q000494:pharmacology; D019061:src-Family Kinases / Q000235:genetics / Q000378:metabolism*
chemical_list: D017382:Reactive Oxygen Species; D024341:Xanthophylls; C005948:astaxanthine; C060902:lyn protein-tyrosine kinase; D019061:src-Family Kinases
keywords: : astaxanthin; acrosome reaction; cholera toxin subunit B (CTB); human sperm capacitation; tyrosine kinase Lyn