Characterization of Human Spermatic Subpopulations by ConA-Binding Sites and Tyrosine Phosphorylation during in vitro Capacitation and Acrosome Reaction

2021 ◽  
pp. 1-9
Author(s):  
Paula Sáez-Espinosa ◽  
Alba López-Huedo ◽  
Laura Robles-Gómez ◽  
Natalia Huerta-Retamal ◽  
Jon Aizpurua ◽  
...  
Keyword(s):  
Tyrosine Phosphorylation ◽  
Binding Sites ◽  
Acrosome Reaction ◽  
Equatorial Region ◽  
Time Dependent ◽  
Strong Connection ◽  
Binding Residues ◽  
The Relationship

Spermatozoa capacitation is a time-dependent physiological process essential for acquiring the fertilizing capacity. In this context, reorganization of spermatozoa surface sugars and tyrosine phosphorylation are some of the most important biochemical changes involved in capacitation. However, the relationship between these 2 biomarkers remains poorly defined. By cytofluorescence we simultaneously characterized the head concanavalin A (ConA)-binding sites and the flagellar tyrosine phosphorylation before capacitation, during different capacitation times (1 and 4 h), and after acrosome reaction induction in human spermatozoa. The results showed a strong connection between ConA-label patterns and tyrosine phosphorylation according to the spermatozoa capacitation time and acrosomal status. Specifically, the spermatozoa subpopulation with phosphotyrosine presented proper sugar location (label in acrosomal and postacrosomal region) just after 1 h of capacitation, while cells without phosphotyrosine needed 4 h to do it. Moreover, after induction of spermatozoa acrosome reaction, phosphorylation was significantly correlated (<i>p</i> &#x3c; 0.05) with the relocation of ConA-binding residues to the equatorial region, regardless of capacitation time. Overall, these observations provide novel insights regarding spermatozoa subpopulations based on essential physiological events like capacitation and acrosome reaction, which could have potential implications in the improvement of spermatozoa selection techniques.

Plasminogen Depletion during Streptokinase Treatment or Two-Chain Urokinase Incubation Correlates with Decreased Clot Lysability Ex Vivo and In Vitro

1993 ◽  
Vol 70 (06) ◽  
pp. 0998-1004 ◽  
Author(s):  
Páll T Önundarson ◽  
H Magnús Haraldsson ◽  
Lena Bergmann ◽  
Charles W Francis ◽  
Victor J Marder
Keyword(s):  
Myocardial Infarction ◽  
Ex Vivo ◽  
Time Dependent ◽  
State Variables ◽  
Thrombolytic Treatment ◽  
Direct Proportion ◽  
Plasmin Activity ◽  
Plasma Exposure ◽  
The Relationship

SummaryThe relationship between lytic state variables and ex vivo clot lysability was investigated in blood drawn from patients during streptokinase administration for acute myocardial infarction. A lytic state was already evident after 5 min of treatment and after 20 min the plasminogen concentration had decreased to 24%, antiplasmin to 7% and fibrinogen 0.2 g/1. Lysis of radiolabeled retracted clots in the patient plasmas decreased from 37 ± 8% after 5 min to 21 ± 8% at 10 min and was significantly lower (8 ± 9%, p <0.005) in samples drawn at 20, 40 and 80 min. Clot lysability correlated positively with the plasminogen concentration (r = 0.78, p = 0.003), but not with plasmin activity. Suspension of radiolabeled clots in normal plasma pre-exposed to 250 U/ml two-chain urokinase for varying time to induce an in vitro lytic state was also associated with decreasing clot lysability in direct proportion with the duration of prior plasma exposure to urokinase. The decreased lysability correlated with the time-dependent reduction in plasminogen concentration (r = 0.88, p <0.0005). Thus, clot lysability decreases in conjunction with the development of the lytic state and the associated plasminogen depletion. The lytic state may therefore limit reperfusion during thrombolytic treatment.

scholarly journals Pharmaceutical properties of 'sucupira' (Pterodon spp.)

2010 ◽  
Vol 46 (4) ◽  
pp. 607-616 ◽  
Author(s):  
Daiane Hansen ◽  
Mitsue Haraguchi ◽  
Antonio Alonso
Keyword(s):  
Biological Effects ◽  
Chemical Compounds ◽  
Experimental Models ◽  
Popular Medicine ◽  
Isolation And Characterization ◽  
Pharmaceutical Properties ◽  
The Relationship

The plant of the genus Pterodon (Fabaceae, Leguminosae), commonly known as 'sucupira' or 'faveira', are disseminated throughout the central region of Brazil and has frequently been used in popular medicine for its anti-rheumatic, analgesic, and anti-inflammatory properties. In recent years, interest in these plants has increased considerably. The biological effects of different phytoextracts and pure metabolites have been investigated in several experimental models in vivo and in vitro. The literature describes flavonoids, triterpene and steroids, while one paper presented studies with proteins isolated from the genus. This review provides an overview of phytochemical and pharmacological research in Pterodon, showing the main chemical compounds studied to date, and focusing on the relationship between these molecules and their biological activity. Furthermore, this study paves the way for more in-depth investigation, isolation and characterization of the molecules of this plant genus.

Testase 1 (ADAM 24) a plasma membrane-anchored sperm protease implicated in sperm function during epididymal maturation or fertilization

2001 ◽  
Vol 114 (9) ◽  
pp. 1787-1794 ◽  
Author(s):  
G.Z. Zhu ◽  
D.G. Myles ◽  
P. Primakoff
Keyword(s):  
Plasma Membrane ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Acrosome Reaction ◽  
Phosphorylation Site ◽  
Equatorial Region ◽  
Proteolytic Processing ◽  
Mature Sperm ◽  
Kinase C

Plasma membrane-anchored proteases have key roles in cell signaling, migration and refashioning the cell surface and its surroundings. We report the first example of a plasma membrane-anchored protease on mature sperm, testase 1 (ADAM 24). Unlike other studied sperm ADAMs (fertilin (α) and (β), cyritestin) whose metalloprotease domains are removed during sperm development, we found testase 1 retains an active metalloprotease domain, suggesting it acts as a protease on mature sperm. Testase 1 is a glycoprotein (molecular mass 88 kDa), localized to the equatorial region of the plasma membrane of cauda epididymal sperm. Typically, proteolytic removal of the pro-domain is an initial activation step for ADAM proteases. The pro-domain of the testase 1 precursor (108 kDa) is proteolytically removed as sperm transit the caput epididymis to produce processed (mature) testase 1 (88 kDa). Testase 1 is unique among all studied ADAMs in that its proteolytic processing occurs on the sperm plasma membrane instead of at an intracellular site (the Golgi). Using GST-fusion proteins and a synthetic testase 1 C-terminal peptide, we found that the cytoplasmic tail of testase 1 could be phosphorylated in vitro by protein kinase C (PKC). Thus testase 1 apparently has a cytoplasmic PKC phosphorylation site(s). Protein kinase C is known to stimulate other ADAMs' protease activity. Because events of the acrosome reaction include PKC activation, we speculate that testase 1 protease function could be important in sperm penetration of the zona pellucida after sperm PKC is activated during the acrosome reaction.

In vitro induction of the acrosome reaction in bull sperm and the relationship to field fertility using low-dose inseminations

2010 ◽  
Vol 73 (9) ◽  
pp. 1180-1191 ◽  
Author(s):  
A. Birck ◽  
P. Christensen ◽  
R. Labouriau ◽  
J. Pedersen ◽  
S. Borchersen
Keyword(s):  
Acrosome Reaction ◽  
Low Dose ◽  
Bull Sperm ◽  
The Relationship ◽  
In Vitro Induction

Localization and characterization of endothelin receptor binding sites in the rat brain visualized by in vitro autoradiography4

Neuroscience ◽  
1991 ◽  
Vol 42 (1) ◽  
pp. 245-260 ◽  
Author(s):  
M. Kohzuki ◽  
S.Y. Chai ◽  
G. Paxinos ◽  
A. Karavas ◽  
D.J. Casley ◽  
...  
Keyword(s):  
Rat Brain ◽  
Receptor Binding ◽  
Binding Sites ◽  
Endothelin Receptor

Structural characterization of new zinc(ii) complexes with N2O2 chelating thiosemicarbazidato ligands; investigation of the relationship between their DNA interaction and in vitro antiproliferative activity towards human cancer cells

2020 ◽  
Vol 44 (22) ◽  
pp. 9313-9320
Author(s):  
Büşra Kaya ◽  
Zehra Kübra Yılmaz ◽  
Onur Şahin ◽  
Belma Aslim ◽  
Bahri Ülküseven
Keyword(s):  
Cancer Cells ◽  
Antiproliferative Activity ◽  
Human Cancer ◽  
Dna Interaction ◽  
Antiproliferative Agents ◽  
Human Cancer Cells ◽  
Dna Targeting ◽  
The Relationship

New candidates to become DNA-targeting antiproliferative agents: Zinc(ii) complexes bearing N2O2-thiosemicarbazidato ligands.

scholarly journals Design, Synthesis and Characterization of a New Series of Fluorescent Metabotropic Glutamate Receptor Type 5 Negative Allosteric Modulators

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1532
Author(s):  
Víctor Fernández-Dueñas ◽  
Mingcheng Qian ◽  
Josep Argerich ◽  
Carolina Amaral ◽  
Martijn D.P. Risseeuw ◽  
...  
Keyword(s):  
Binding Sites ◽  
Metabotropic Glutamate Receptor ◽  
Allosteric Modulators ◽  
Design Synthesis ◽  
Metabotropic Glutamate ◽  
Animal Disease Models ◽  
Fluorescent Ligands ◽  
The Brain

In recent years, new drug discovery approaches based on novel pharmacological concepts have emerged. Allosteric modulators, for example, target receptors at sites other than the orthosteric binding sites and can modulate agonist-mediated activation. Interestingly, allosteric regulation may allow a fine-tuned regulation of unbalanced neurotransmitter’ systems, thus providing safe and effective treatments for a number of central nervous system diseases. The metabotropic glutamate type 5 receptor (mGlu5R) has been shown to possess a druggable allosteric binding domain. Accordingly, novel allosteric ligands are being explored in order to finely regulate glutamate neurotransmission, especially in the brain. However, before testing the activity of these new ligands in the clinic or even in animal disease models, it is common to characterize their ability to bind mGlu5Rs in vitro. Here, we have developed a new series of fluorescent ligands that, when used in a new NanoBRET-based binding assay, will facilitate screening for novel mGlu5R allosteric modulators.

scholarly journals Immunochemical characterization of two thyroid-stimulating hormone β-subunit epitopes

1995 ◽  
Vol 308 (1) ◽  
pp. 203-210 ◽  
Author(s):  
W D Fairlie ◽  
P G Stanton ◽  
M T W Hearn
Keyword(s):  
Receptor Binding ◽  
Binding Sites ◽  
Thyroid Stimulating Hormone ◽  
Beta Subunit ◽  
Human Thyroid ◽  
Lysine Residues ◽  
Sequence Region ◽  
The Relationship ◽  
Stimulating Hormone

The epitopes of human thyroid-stimulating hormone (hTSH) recognized by two murine monoclonal antibodies (MAbs), designated MAb 279 and MAb 299, have been characterized. These MAbs are highly specific for the beta-subunit of TSH. The epitope recognized by MAb 279 appears to be completely conserved between bovine and human TSH and partially conserved in the porcine species. The TSH beta-subunit epitope recognized by MAb 299 is only partially conserved between the human, bovine and porcine species. Both MAbs are capable of inhibiting the binding of TSH to its receptor in a TSH radioreceptor assay, indicating that the epitopes either coincide or are located close to the TSH beta-subunit receptor-binding sites. The carbohydrate moieties of the TSH beta-subunit appear to play little or no role in the epitope recognition by MAb 279 or MAb 299 while the integrity of the disulphide bonds are essential. The epitopic recognition may also involve lysine residues, as determined by the immunoreactivity with both MAbs following citraconylation of TSH. In addition, the amino acid sequence region between residues bTSH beta 34-44 could be excised by trypsin digestion of bovine TSH beta (bTSH beta) without eliminating epitopic recognition by either MAb. These results provide further insight into the relationship between the structure of the TSH beta-subunit epitopes and location of the receptor-binding sites.

scholarly journals Uterine flushings from women treated with levonorgestrel affect sperm functionality in vitro

Reproduction ◽  
2017 ◽  
Vol 154 (5) ◽  
pp. 607-614 ◽  
Author(s):  
Mayel Chirinos ◽  
Marta Durand ◽  
María Elena González-González ◽  
Gabriela Hernández-Silva ◽  
Israel Maldonado-Rosas ◽  
...  
Keyword(s):  
Tyrosine Phosphorylation ◽  
Emergency Contraception ◽  
Acrosome Reaction ◽  
Binding Capacity ◽  
Human Sperm ◽  
Contraceptive Efficacy ◽  
Serum Luteinizing Hormone ◽  
Emergency Contraceptive ◽  
Testosterone Derivative

Levonorgestrel (LNG), a synthetic 19 nor-testosterone derivative, is widely used for emergency contraception. It is well known that LNG prevents ovulation only when given prior to the surge of serum luteinizing hormone (LH) during the periovulatory phase of the menstrual cycle. This observation suggests that LNG, given its contraceptive efficacy, has additional effects other than those affecting ovulation. In this study, we have evaluated the effects on human sperm functionality of uterine flushings (UF) obtained from women at day LH + 1 of a control cycle (CTR-LH + 1) and after receiving LNG (LNG-LH + 1) two days before the surge of LH. Human sperm from normozoospermic donors were incubated with UF and protein tyrosine phosphorylation, sperm motility, acrosome reaction as well as zona pellucida (ZP) binding capacity were assessed. A significant decrease in total motility and tyrosine phosphorylation accompanied by an increase on spontaneous acrosome reaction was observed when sperm were incubated in the presence of LNG-LH + 1. None of these effects were mimicked by purified glycodelin A (GdA). Moreover, the addition of UF obtained during the periovulatory phase from LNG-treated women or the presence of purified GdA significantly decreased sperm-ZP binding. The data were compatible with changes affecting sperm capacitation, motility and interaction with the ZP. These results may offer evidence on additional mechanisms of action of LNG as an emergency contraceptive.

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