scholarly journals Mechanism of sperm capacitation and the acrosome reaction: role of protein kinases

2012 ◽  
Vol 14 (6) ◽  
pp. 816-821 ◽  
Author(s):  
Debby Ickowicz ◽  
Maya Finkelstein ◽  
Haim Breitbart
2012 ◽  
Vol 1 (1) ◽  
pp. 18
Author(s):  
Amrit Kaur Bansal ◽  
Ranjna Sundhey Cheema ◽  
Vinod Kumar Gandotra

The aim of this paper was to investigate the antioxidant effect of Mn2+ (200 mM) on the sperm capacitation and acrosome reaction of fresh and chilled cattle bull semen. It has been found that Mn2+ supplementation improves (P≤0.05) the motility at 0, 2, 4 and 6 h of incubation. MDA (malondialdehyde), end product of lipid peroxidation, decreases significantly (P≤0.05) with the supplementation of manganese at 0- and 6-hr of incubation both in fresh and chilled semen. Manganese also increases acrosome reaction significantly (P≤0.05) both in fresh and chilled semen at 0, 4 and 6 h of incubation. Therefore, our findings suggest the role of Mn2+supplementation in improving the quality of cattle bull semen by its scavenging property<em> i.e.</em> reduction in the production of reactive oxygen species during its storage at 4°C or incubation at 37°C for capacitation.


1991 ◽  
Vol 278 (1) ◽  
pp. 25-28 ◽  
Author(s):  
S Rubinstein ◽  
H Breitbart

The binding properties of seminal polyamines to ram spermatozoa and their possible role in sperm capacitation and the acrosome reaction were studied. Binding and release of [14C]spermine from ram spermatozoa occurred at a rate faster than in somatic cells and were not energy-dependent. Release of bound spermine was further facilitated by heparin, a constituent of the female reproductive tract which was reported to induce capacitation and the acrosome reaction. High- and low-affinity polyamine-binding sites were identified, of which the high-affinity site was specific to polyamines with three or more amino groups. We also found that spermine inhibited the acrosome reaction and propose that it is the major seminal decapacitating factor. Since precise timing of capacitation and the acrosome reaction are critical for successful fertilization, it is suggested that the role of seminal spermine is to prevent premature capacitation and the acrosome reaction.


2011 ◽  
Vol 85 (Suppl_1) ◽  
pp. 378-378 ◽  
Author(s):  
Xiaojing Yang ◽  
Ian Garrison ◽  
Zhongchao Jia ◽  
Catherine Lachance ◽  
Pierre Leclerc ◽  
...  

2020 ◽  
Vol 7 (2) ◽  
pp. 205-211
Author(s):  
Kaynat Fatima ◽  
Syed Tasleem Raza ◽  
Ale Eba ◽  
Sanchita Srivastava ◽  
Farzana Mahdi

The function of protein kinases is to transfer a γ-phosphate group from ATP to serine, threonine, or tyrosine residues. Many of these kinases are linked to the initiation and development of human cancer. The recent development of small molecule kinase inhibitors for the treatment of different types of cancer in clinical therapy has proven successful. Significantly, after the G-protein-coupled receptors, protein kinases are the second most active category of drug targets. Imatinib mesylate was the first tyrosine kinase inhibitor (TKI), approved for chronic myeloid leukemia (CML) treatment. Imatinib induces appropriate responses in ~60% of patients; with ~20% discontinuing therapy due to sensitivity, and ~20% developing drug resistance. The introduction of newer TKIs such as, nilotinib, dasatinib, bosutinib, and ponatinib has provided patients with multiple options. Such agents are more active, have specific profiles of side effects and are more likely to reach the necessary milestones. First-line treatment decisions must be focused on CML risk, patient preferences and comorbidities. Given the excellent result, half of the patients eventually fail to seek first-line treatment (due to discomfort or resistance), with many of them needing a third or even further therapy lines. In the present review, we will address the role of tyrosine kinase inhibitors in therapy for chronic myeloid leukemia.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rasoul Kowsar ◽  
Shahrzad Ronasi ◽  
Nima Sadeghi ◽  
Khaled Sadeghi ◽  
Akio Miyamoto

AbstractUpon insemination, sperm cells are exposed to components of the female reproductive tract (FRT) fluids, such as urea and epidermal growth factor (EGF). It has been shown that both urea and EGF use EGF receptor signaling and produce reactive oxygen species (ROS) that are required at certain levels for sperm capacitation and acrosome reaction. We therefore hypothesized that during bovine sperm capacitation, a high level of urea and EGF could interfere with sperm function through overproduction of ROS. High-level urea (40 mg/dl urea is equal to 18.8 mg/dl of blood urea nitrogen) significantly increased ROS production and TUNEL-positive sperm (sperm DNA fragmentation, sDF) percentage, but decreased HOS test score, progressive motility, acrosome reaction and capacitation. The EGF reversed the negative effects of urea on all sperm parameters, with the exception of ROS production and DNA fragmentation, which were higher in urea-EGF-incubated sperm than in control-sperm. The developmental competence of oocytes inseminated with urea-EGF-incubated sperm was significantly reduced compared to the control. A close association of ROS production or sDF with 0-pronuclear and sperm non-capacitation rates was found in the network analysis. In conclusion, EGF enhanced urea-reduced sperm motility; however, it failed to reduce urea-increased sperm ROS or sDF levels and to enhance subsequent oocyte competence. The data suggests that any study to improve sperm quality should be followed by a follow-up assessment of the fertilization outcome.


Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 875
Author(s):  
Gerald Thiel ◽  
Tobias Schmidt ◽  
Oliver G. Rössler

Ca2+ ions function as second messengers regulating many intracellular events, including neurotransmitter release, exocytosis, muscle contraction, metabolism and gene transcription. Cells of a multicellular organism express a variety of cell-surface receptors and channels that trigger an increase of the intracellular Ca2+ concentration upon stimulation. The elevated Ca2+ concentration is not uniformly distributed within the cytoplasm but is organized in subcellular microdomains with high and low concentrations of Ca2+ at different locations in the cell. Ca2+ ions are stored and released by intracellular organelles that change the concentration and distribution of Ca2+ ions. A major function of the rise in intracellular Ca2+ is the change of the genetic expression pattern of the cell via the activation of Ca2+-responsive transcription factors. It has been proposed that Ca2+-responsive transcription factors are differently affected by a rise in cytoplasmic versus nuclear Ca2+. Moreover, it has been suggested that the mode of entry determines whether an influx of Ca2+ leads to the stimulation of gene transcription. A rise in cytoplasmic Ca2+ induces an intracellular signaling cascade, involving the activation of the Ca2+/calmodulin-dependent protein phosphatase calcineurin and various protein kinases (protein kinase C, extracellular signal-regulated protein kinase, Ca2+/calmodulin-dependent protein kinases). In this review article, we discuss the concept of gene regulation via elevated Ca2+ concentration in the cytoplasm and the nucleus, the role of Ca2+ entry and the role of enzymes as signal transducers. We give particular emphasis to the regulation of gene transcription by calcineurin, linking protein dephosphorylation with Ca2+ signaling and gene expression.


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