scholarly journals Murine binder of sperm protein homolog 1: a new player in HDL-induced capacitation

Reproduction ◽  
2015 ◽  
Vol 149 (4) ◽  
pp. 367-376 ◽  
Author(s):  
Geneviève Plante ◽  
Puttaswamy Manjunath
Keyword(s):  
Specific Interaction ◽  
Main Function ◽  
Sperm Capacitation ◽  
Epididymal Sperm ◽  
Male Genital Tract ◽  
Direct Role ◽  
Bsp Proteins ◽  
Male Genital

Binder of sperm (BSP) proteins are ubiquitous among mammals and are exclusively expressed in male genital tract. The main function associated with BSP proteins is their ability to promote sperm capacitation. In mice, two proteins (BSP protein homolog 1 (BSPH1) and BSPH2) have been studied. Using recombinant strategies, BSPH1 was found to bind to epididymal sperm membranes and promote sperm capacitation in vitro. The goal of this study was to evaluate the role of native murine BSPH1 protein in sperm capacitation induced by BSA and HDLs. The effect of antibodies, antigen-binding fragments (Fabs), and F(ab′)2 specific for murine BSPH1 on BSA- and HDL-induced capacitation was tested. Results indicate that BSPH1 has no direct role in BSA-induced capacitation. However, antibodies, Fabs, and F(ab′)2 could block capacitation induced by HDLs and could inhibit the HDL-induced increase in tyrosine phosphorylation, suggesting a specific interaction between HDLs and BSPH1. Results indicate that murine BSPH1 proteins in mice could be a new important piece of the puzzle in sperm capacitation induced by HDLs. As murine BSPH1 is orthologous to human BSPH1, this study could also lead to new insights into the functions and the importance of the human protein in male fertility.Free French abstractA French translation of this abstract is freely available at http://www.reproduction-online.org/content/149/4/367/suppl/DC1.

scholarly journals Inhibition of hepatic deiodination of thyroxine is caused by selenium deficiency in rats

1987 ◽  
Vol 248 (2) ◽  
pp. 443-447 ◽  
Author(s):  
G J Beckett ◽  
S E Beddows ◽  
P C Morrice ◽  
F Nicol ◽  
J R Arthur
Keyword(s):  
Thyroid Hormones ◽  
Production Rate ◽  
Selenium Deficiency ◽  
Enzyme Complex ◽  
Measurable Effect ◽  
Direct Role ◽  
Mechanism Of Inhibition ◽  
Se Deficiency

Selenium (Se) deficiency produced up to a 14-fold decrease in hepatic tri-iodothyronine (T3) production from thyroxine (T4) in vitro. The T3 production rate could not be restored by the addition of a variety of cofactors, nor by the addition of control homogenate. The impairment in hepatic T3 production observed in Se deficiency was reflected in the concentrations of thyroid hormones circulating in plasma, T4 being increased approx. 40% and T3 being decreased by 30%. However, the fall in plasma T3 concentrations was smaller than might be expected in view of the marked decreased in T3 production. Se deficiency had no measurable effect on plasma reverse-tri-iodothyronine concentrations. The data suggest that Se deficiency produces an inhibition of both 5- and 5′-deiodination, consistent with the widely held view that these reactions are catalysed by the same enzyme complex. The mechanism of inhibition appears not be mediated by changes in thiol levels, but a direct role of Se in the activity of the deiodinase complex cannot be excluded.

scholarly journals Mutations affecting the tRNA-splicing endonuclease activity of Saccharomyces cerevisiae.

Genetics ◽  
1988 ◽  
Vol 118 (4) ◽  
pp. 609-617
Author(s):  
M Winey ◽  
M R Culbertson
Keyword(s):  
Growth Defect ◽  
Temperature Sensitive ◽  
Gene Products ◽  
Endonuclease Activity ◽  
Temperature Dependent ◽  
Direct Role ◽  
Trna Splicing

Abstract Two unlinked mutations that alter the enzyme activity of tRNA-splicing endonuclease have been identified in yeast. The sen1-1 mutation, which maps on chromosome 12, causes temperature-sensitive growth, reduced in vitro endonuclease activity, and in vivo accumulation of unspliced pre-tRNAs. The sen2-1 mutation does not confer a detectable growth defect, but causes a temperature-dependent reduction of in vitro endonuclease activity. Pre-tRNAs do not accumulate in sen2-1 strains. The in vitro enzyme activities of sen1-1 and sen2-1 complement in extracts from a heterozygous diploid, but fail to complement in mixed extracts from separate sen1-1 and sen2-1 haploid strains. These results suggest a direct role for SEN gene products in the enzymatic removal of introns from tRNA that is distinct from the role of other products known to affect tRNA splicing.

Assessment of binder of sperm protein 1 (BSP1) and heparin effects on in vitro capacitation and fertilization of bovine ejaculated and epididymal sperm

Zygote ◽  
2020 ◽  
Vol 28 (6) ◽  
pp. 489-494
Author(s):  
Paula Rodríguez-Villamil ◽  
Daiane Mentz ◽  
Felipe Ledur Ongaratto ◽  
Luis Henrique Aguiar ◽  
Jose Luiz Rodrigues ◽  
...  
Keyword(s):  
Control Group ◽  
Sperm Capacitation ◽  
Epididymal Sperm ◽  
Sperm Protein ◽  
Fertilization Rates ◽  
Bovine Sperm ◽  
Development Rates ◽  
Developmental Rates

SummaryThe present study evaluated the effect of binder of sperm protein 1 (BSP1) and/or heparin on in vitro bovine capacitation and fertilization rates using epididymal and ejaculated bovine sperm. Frozen–thawed sperm were selected and used in the following treatments. Control group: Fert-TALP medium without heparin; heparin (HEP) group: Fert-TALP with heparin (10 UI/ml); BSP1 group: Fert-TALP medium with BSP1 (10 µg/ml for ejaculated sperm; 40 µg/ml for epididymal sperm); HEP + BSP1 group: Fert-TALP medium with heparin (5 UI/ml) and BSP1 (5 µg/ml for ejaculated sperm; 20 µg/ml for epididymal sperm) and determined in vitro capacitation rates in different interval times (0, 15, 30 and 60 min) using the chlortetracycline fluorescence (CTC) method. Also, we evaluated the development rates of oocytes fertilized with ejaculated or epididymal sperm into the same treatments. Capacitation was greater and faster when ejaculated sperm were treated for 60 min with heparin compared with other treatments. However, developmental rates were similar in all treatments. For epididymal sperm, the treatments with BSP1 presented higher capacitation and fertilization rates compared with heparin (P < 0.05). The effects of heparin + BSP1 on capacitation and developmental rates did not cause any increase in capacitation or blastocyst rates compared with other groups for ejaculated or epididymal sperm. In conclusion, this study confirmed that either BSP1 and heparin can be used as capacitator agents for bovine ejaculated sperm during IVF. However, BSP1 seems to be more efficient compared with heparin for epididymal sperm. Furthermore, BSP1 and heparin have no synergic effects on sperm capacitation.

scholarly journals Transcription factor MBF-I interacts with metal regulatory elements of higher eucaryotic metallothionein genes.

1989 ◽  
Vol 9 (12) ◽  
pp. 5315-5323 ◽  
Author(s):  
J Imbert ◽  
M Zafarullah ◽  
V C Culotta ◽  
L Gedamu ◽  
D Hamer
Keyword(s):  
Gene Transcription ◽  
Regulatory Elements ◽  
Gene Promoters ◽  
Direct Role ◽  
Transcription In Vitro ◽  
Mouse Cells ◽  
Affinity Reagent

Metallothionein (MT) gene promoters in higher eucaryotes contain multiple metal regulatory elements (MREs) that are responsible for the metal induction of MT gene transcription. We identified and purified to near homogeneity a 74-kilodalton mouse nuclear protein that specifically binds to certain MRE sequences. This protein, MBF-I, was purified employing as an affinity reagent a trout MRE that is shown to be functional in mouse cells but which lacks the G+C-rich and SP1-like sequences found in many mammalian MT gene promoters. Using point-mutated MREs, we showed that there is a strong correlation between DNA binding in vitro and MT gene regulation in vivo, suggesting a direct role of MBF-I in MT gene transcription. We also showed that MBF-I can induce MT gene transcription in vitro in a mouse extract and that this stimulation requires zinc.

scholarly journals In vivo exposure to 17β-estradiol triggers premature sperm capacitation in cauda epididymis

Reproduction ◽  
2013 ◽  
Vol 145 (3) ◽  
pp. 255-263 ◽  
Author(s):  
Lukas Ded ◽  
Natasa Sebkova ◽  
Martina Cerna ◽  
Fatima Elzeinova ◽  
Pavla Dostalova ◽  
...  
Keyword(s):  
Reproductive Tract ◽  
Negative Impact ◽  
Reproductive Potential ◽  
Female Reproductive Tract ◽  
Sperm Capacitation ◽  
Epididymal Sperm ◽  
Knock Out ◽  
17Β Estradiol

Estrogens play a crucial role in spermatogenesis and estrogen receptor α knock-out male mice are infertile. It has been demonstrated that estrogens significantly increase the speed of capacitation in vitro; however this may lead to the reduction of reproductive potential due to the decreased ability of these sperm to undergo the acrosome reaction. To date the in vivo effect of estrogens on the ability of sperm to capacitate has not been investigated. Therefore, in this study, we exposed mice (n=24) to 17β-estradiol (E2) at the concentration of 20 ng/ml either during puberty from the fourth to seventh week of age (n=8), or continuously from birth for a period of 12 weeks (n=8) at which age the animals from both groups were killed. The capacitation status of epididymal and testicular sperm was analysed by tyrosine phosphorylation (TyrP) antibody (immunofluorescence and western blot) and chlortetracycline (CTC) assay. According to our results, in vivo exposure to increased E2 concentrations caused premature sperm capacitation in the epididymis. The effect of E2, however, seems reversible because after the termination of the exposure premature epididymal sperm capacitation is decreased in animals treated during puberty. Furthermore the changes in epididymal sperm capacitation status detected by TyrP and CTC positively correlate with plasma levels of E2 and the expression of the estrogen-dependent trefoil factor 1 (Tff1) gene in testicular tissue. Therefore, our data implicate that in vivo exposure to E2 under specific conditions leads to the premature capacitation of mouse sperm in epididymis with a potential negative impact on the sperm reproductive fitness in the female reproductive tract.

scholarly journals Wnt/beta-catenin signalling is dispensable for adult neural stem cell homeostasis and activation

2020 ◽  
Author(s):  
Sophie H. L. Austin ◽  
Lachlan Harris ◽  
Oana Paun ◽  
Piero Rigo ◽  
François Guillemot ◽  
...  
Keyword(s):  
Stem Cell ◽  
Beta Catenin ◽  
Dependent Manner ◽  
Direct Role ◽  
Adult Nscs ◽  
Hippocampal Networks ◽  
Dose Dependent

AbstractAdult mouse hippocampal neural stem cells (NSCs) generate new neurons that integrate into existing hippocampal networks and modulate mood and memory. These NSCs are largely quiescent and are stimulated by niche signals to activate and produce neurons. Wnt/β-catenin signalling acts at different steps along the hippocampal neurogenic lineage and has been shown to promote the proliferation of intermediate progenitor cells. However, whether it has a direct role in the regulation of NSCs still remains unclear. Here we used Wnt/β-catenin reporters and transcriptomic data from in vivo and in vitro models to show that both active and quiescent adult NSCs respond to Wnt/β-catenin signalling. Wnt/β-catenin stimulation instructed neuronal differentiation of active NSCs and promoted the activation or differentiation of quiescent NSCs in a dose-dependent manner. However, we found that inhibiting NSCs response to Wnt, by conditionally deleting β-catenin, did not affect their activation or maintenance of their stem cell characteristics. Together, our results indicate that whilst NSCs do respond to Wnt/β-catenin stimulation in a dose-dependent and state-specific manner, Wnt/β-catenin signalling is not cell-autonomously required to maintain NSC homeostasis, which could reconcile some of the contradictions in the literature as to the role of Wnt/β-catenin signalling in adult hippocampal NSCs.

The Role of Prostaglandins in the ADP-Induced Aggregation of Rabbit Platelets Shown by the Use of 15-Hydroxyprostaglandin Dehydrogenase

1978 ◽  
Vol 39 (03) ◽  
pp. 725-732 ◽  
Author(s):  
Robert B Wallis
Keyword(s):  
Platelet Rich Plasma ◽  
Shape Change ◽  
Rabbit Platelet ◽  
Direct Role ◽  
Initial Shape ◽  
Rabbit Platelets ◽  
Induced Aggregation ◽  
Aggregation Of Platelets

SummaryThe initial shape change and subsequent aggregation of platelets in citrated rabbit platelet-rich plasma caused by ADP in vitro was inhibited by 15-hydroxyprostaglandin dehydrogenase. This inhibition was NAD-dependent and was also seen when shape change and aggregation were initiated by sodium arachidonate or by collagen. The aggregation of gel-filtered rabbit platelets by thrombin was not, however, affected by removal of 15-hydroxyprostaglandins.Indomethacin was found to inhibit ADP-induced aggregation but at a concentration (250 μM) much higher than that required to inhibit collagen-induced aggregation. Moreover the platelet release reaction had not taken place 3 min after ADP stimulation. The direct role 15-hydroxyprostaglandin production in ADP-induced aggregation of rabbit platelets is proposed. The involvement of 15-hydroxyprostaglandins in platelet aggregation caused by other inducers is also discussed.

PDIA3 Reduce Glioma-associated Macrophage/microglia Pro-tumor Activation trough IL-6-STAT3-PDIA3 Pathway.

2020 ◽  
Author(s):  
Marta Chiavari ◽  
Gabriella Maria Pia Ciotti ◽  
Francesco Canonico ◽  
Fabio Altieri ◽  
Pierluigi Navarra ◽  
...  
Keyword(s):  
Overall Survival ◽  
Endoplasmic Reticulum ◽  
The Cancer Genome Atlas ◽  
Main Function ◽  
Physiological Processes ◽  
Relevant Role ◽  
Cancer Genome Atlas ◽  
Thiol Oxidoreductase

Abstract Background: Glioblastoma (GB - grade IV glioma) is the most aggressive and common cancer of central nervous system with an overall survival of 14-16 months. The GB tumor microenvironment includes cells of the innate immune system identified as glioma-associated microglia/macrophages (GAMs). It is known that between GAMs and GB cells there is a double interaction, but the role of GAMs is still poorly characterized. The endoplasmic reticulum (ER) protein ERp57, also known as PDIA3, is a thiol oxidoreductase with main function related on glycoprotein folding in endoplasmic reticulum. However, PDIA3 shows different functions. In fact, the various subcellular localizations and binding partners of PDIA3 affect numerous physiological processes and diseases: different regulation and modulation of PDIA3 has been reported in multiple pathologies including neurodegenerative diseases and cancer. Methods: In the present work, we evaluated in both GB cells and microglia-macrophage cells the expression of PDIA3 using specimens collected after surgical from 18 GB patients. In addition, we studied in vitro microglia-glioma interaction to determine the role of PDIA3 in viability and the activation of both GB and microglia cells. The study was carried using PDIA3-silenced T98G cells and/or using a pharmacological inhibitor of PDIA3 activity (Punicalagin-PUN).Results: We initially investigated the role of the PDIA3 in GB survival by inquiring The Cancer Genome Atlas dataset. The results indicated that 352 out of 690 patients reported over-expression of PDIA3, which significantly correlated with a ~55% reduction of overall survival. Subsequently, for the first time, we investigated the PDIA3 expression in the tumor and the nearby parenchyma of 18 GB patients and our data showed a significant upregulation (15% vs 10%) of ERp57/PDIA3 in GAMs of tumor specimens respect the microglia present in parenchyma. In addition, we show that conditioned medium (CMs) obtained from both wild type T98G and PDIA3 silenced T98G induced an activation of microglia cells, but the PDIA3 silenced-T98G CMs significant limited the microglia pro-tumor activation probably through a IL-6-STAT3-PDIA3 dependent mechanism. Conclusion: Our data support the relevant role of PDIA3 expression in GB pathology and link the different activation of microglia to a mechanism a IL-6-STAT3-PDIA3 dependent.

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