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The Journey of the Porcine Spermatozoa from Its Origin to the Fertilization Site: The Road In Vivo vs. In Vitro
Published in Juan Carlos Gardón, Katy Satué, Biotechnologies Applied to Animal Reproduction, 2020
Cristina Soriano-Úbeda, Francisco Alberto García-Vázquez, Carmen Matás
Sperm capacitation is a complex and lengthy physiological process that involves a combination of sequential and parallel molecular changes that affect both the spermatozoa head and tail (Suarez, 2007). It is a critical point to the acquisition of the ability of the spermatozoa to fertilize the oocyte.
Capacitation, the Acrosome Reaction, and Motility in Mammalian Sperm
Published in Claude Gagnon, Controls of Sperm Motility, 2020
Susan S. Suarez, John W. Pollard
Nearly 40 years after its discovery, the process of capacitation is still only incompletely understood. It is generally agreed that capacitation entails the loss of coating factors from the sperm surface, which results in the exposure of sites receptive to the induction of the acrosome reaction and fusion with the oocyte plasma membrane.20 Nevertheless, capacitation may be a complex process, involving other changes beyond this. Soon after capacitation was first described, it was considered in more general terms as the process that prepared spermatozoa for fertilization.21,22 This more generalized definition resulted in the inclusion of other physiological events under the umbrella of the term capacitation, as well as confusion about the requirements and processes of capacitation. Among these events were the acrosome reaction and the onset of hyperactivated motility. The acrosome reaction, required for the penetration of the zona pellucida and fusion with the oocyte plasma membrane, is now considered as a separate event that occurs after capacitation.3 Capacitation is a reversible process, but the acrosome reaction is not. Hyperactivation should also be considered as a separate event at this point for reasons presented here.
JAK-STAT pathway: Testicular development, spermatogenesis and fertility
Published in Rajender Singh, Molecular Signaling in Spermatogenesis and Male Infertility, 2019
JAK-STAT signaling may be one of the many pathways that are required by sperm in acquiring the ability to fertilize the ovum. The process of capacitation involves various biochemical and physiological changes, which involve an increase in membrane fluidity, Ca2+ concentration and protein tyrosine phosphorylation (83). Since both capacitation and the JAK-STAT pathway involve an increase in protein tyrosine phosphorylation, the extent of protein tyrosine phosphorylation of JAK and STAT proteins of capacitated spermatozoa in response to various cytokines was assessed. It was found that STAT1 and STAT4 in human spermatozoa undergo tyrosine phosphorylation in response to interferons (IFNα and IFNγ) and interleukin-12 (IL-12) (81). These results supported the existence of the JAK-STAT pathway in human spermatozoa.
Participation of signaling proteins in sperm hyperactivation
Published in Systems Biology in Reproductive Medicine, 2022
Joaquín Cordero-Martínez, Guadalupe Elizabeth Jimenez-Gutierrez, Charmina Aguirre-Alvarado, Verónica Alacántara-Farfán, Germán Chamorro-Cevallos, Ana L. Roa-Espitia, Enrique O. Hernández-González, Lorena Rodríguez-Páez
Capacitation is influenced by the activities of a wide variety of proteins. Soluble adenylyl cyclase (sAC) strongly influences the signaling cascade that controls sperm motility (Esposito et al. 2004; Buffone et al. 2014). sAC activity is modulated by the presence of HCO3− (Xie et al. 2006; Wang D et al. 2007), and its activation leads to the production of adenosine 3′,5′-cyclic monophosphate (cAMP), which in turn modulates the sperm-specific Na+/H+ exchanger (sNHE) (Wang D et al. 2007; Touré 2019). sNHE is an integral membrane protein that regulates the Na+/H+ exchange and pHi of rodent sperms during capacitation (Chen SR, Batool, et al. 2016; Zhang et al. 2017). The t-complex protein 11 (TCP11) is yet another protein that exerts strong influence over the signaling pathway such as cAMP/PKA and tyrosine phosphorylation and sperm motility (Castaneda et al. 2020).
What is the fertility-enhancing effect of tubal flushing? A hypothesis article
Published in Journal of Obstetrics and Gynaecology, 2022
Inez Roest, Amir M. Hajiyavand, Marlies Y. Bongers, Velja Mijatovic, Ben Willem J. Mol, Carolien A. M. Koks, Karl D. Dearn
The female genital tract contains oviductal fluid, produced by the transudate fluid from the systematic circulation and secretory ciliated epithelial cells within the oviduct (Li and Winuthayanon 2017). When the spermatozoa come into contact with the oviductal fluid, they undergo essential changes, starting with the capacitation process. As a result of this, the motility of the spermatozoa increases through hyperactivation. This process provides a vital force to overcome the attraction between the spermatozoa and the tubal-epithelium (see Figure 4). The epithelium itself also plays a crucial role in the spermatozoa’s detachment; however, this process’s mechanisms are unknown (Suarez and Pacey 2006). Oil-based contrast may reduce interfacial bonding during capacitation and hyperactivation, and therefore enhance the fertility outcomes. There are no studies available that tested this hypothesis.
Probiotic effects on sperm parameters, oxidative stress index, inflammatory factors and sex hormones in infertile men
Published in Human Fertility, 2022
Bijan Helli, Maria Kavianpour, Ehsan Ghaedi, Mohammadreza Dadfar, Hossein Khadem Haghighian
The human body system has a defensive system for dealing with free radicals called the antioxidant system (Forman et al., 2015). The imbalance between the produced free radical amounts and the antioxidant capacity causes oxidative stress (Bhattacharya, 2015). Reactive oxygen species (ROS) in physiological numbers are required for sperm motility, hyperactivation, capacitation, acrosome reaction and nuclear condensation. However, pathological levels of ROS can damage sperm function and reduce sperm motility, mainly through exhaustion of intracellular Adenosine triphosphate (ATP), and lipid peroxidation of the plasma membrane (Ayaz et al., 2018). In patients with infertility, the level of free radicals was significantly higher than that of healthy subjects and therefore, it seems that the reproductive capacity has a significant relationship with the intake of dietary antioxidants (Bui et al., 2018).