scholarly journals Capacitation-Induced Mitochondrial Activity Is Required for Sperm Fertilizing Ability in Mice by Modulating Hyperactivation

Author(s):  
María Milagros Giaccagli ◽  
Matías Daniel Gómez-Elías ◽  
Jael Dafne Herzfeld ◽  
Clara Isabel Marín-Briggiler ◽  
Patricia Sara Cuasnicú ◽  
...  

To become fully competent to fertilize an egg, mammalian sperm undergo a series of functional changes within the female tract, known as capacitation, that require an adequate supply and management of energy. However, the contribution of each ATP generating pathway to sustain the capacitation-associated changes remains unclear. Based on this, we investigated the role of mitochondrial activity in the acquisition of sperm fertilizing ability during capacitation in mice. For this purpose, the dynamics of the mitochondrial membrane potential (MMP) was studied by flow cytometry with the probe tetramethylrhodamine ethyl ester (TMRE). We observed a time-dependent increase in MMP only in capacitated sperm as well as a specific staining with the probe in the flagellar region where mitochondria are confined. The MMP rise was prevented when sperm were exposed to the mitochondrial uncoupler carbonyl cyanide m-chlorophenyl hydrazine (CCCP) or the protein kinase A (PKA) inhibitor H89 during capacitation, indicating that MMP increase is dependent on capacitation and H89-sensitive events. Results showed that whereas nearly all motile sperm were TMRE positive, immotile cells were mostly TMRE negative, supporting an association between high MMP and sperm motility. Furthermore, CCCP treatment during capacitation did not affect PKA substrate and tyrosine phosphorylations but produced a decrease in hyperactivation measured by computer assisted sperm analysis (CASA), similar to that observed after H89 exposure. In addition, CCCP inhibited the in vitro sperm fertilizing ability without affecting cumulus penetration and gamete fusion, indicating that the hyperactivation supported by mitochondrial function is needed mainly for zona pellucida penetration. Finally, complementary in vivo fertilization experiments further demonstrated the fundamental role of mitochondrial activity for sperm function. Altogether, our results show the physiological relevance of mitochondrial functionality for sperm fertilization competence.

Animals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1329
Author(s):  
Michele Di Iorio ◽  
Giusy Rusco ◽  
Roberta Iampietro ◽  
Lucia Maiuro ◽  
Achille Schiavone ◽  
...  

This study was designed to test the fertilizing ability of cryopreserved turkey semen, and here, two experiments were performed: an in vitro analysis to assess the effects of Tselutin and Lake diluents and an in vivo test to determine the fertility and hatching rates by also studying the feat of three insemination doses (250, 400 and 600 × 106 sperm/hen). Pooled semen samples were diluted with Tselutin or Lake extender which contained 20% of dimethylsulfoxide and 1 mM of Ficoll at final sperm concentration of 3 × 109 sperm/mL. Thereafter, semen was packaged into straws and frozen on liquid nitrogen. The post-thaw sperm quality was evaluated considering motility (computer-aided sperm analysis—CASA system) and membrane integrity (flow cytometry). Significantly higher values of progressive motility and some kinetic parameters in semen frozen with Lake were found. When we compared the extenders in vivo, no significant effects were detected, whilst sperm concentration significantly affected both fertility and hatching rates, with the best results obtained with the sperm concentration of 400 × 106 sperm/hen. From the results obtained, it emerged that the extender type only affected sperm motility characteristics, not the fertilizing ability of frozen-thawed semen, while inseminating dose markedly affected fertility and hatching rates.


2019 ◽  
Vol 1 (4) ◽  
pp. 36-40
Author(s):  
Michal Ďuračka

The use of antibiotics is a common part of animal biotechnologies. Especially, the use of antibiotics in semen extenders is necessary. However, the effect of antibiotics on the spermatozoa structure and function is still not completely examined. Therefore, the aim of our study was to investigate the effect of kanamycin on bovine spermatozoa at concentrations of 80 and 160 µg/mL during the 24 h in vitro cultivation. Semen samples were collected from clinically healthy Holstein-Friesian bulls. At times of 0, 2 and 24 h the motility assessment, mitochondrial activity, acrosomal and membrane integrity evaluation were performed. The sperm motility was measured using the Computer-assisted sperm analysis (CASA). Mitochondrial activity was evaluated through the Mitochondrial Toxicity Test (MTT). The acrosomal status was determined using the fast green/rose bengal staining on slides. Similarly, the membrane integrity was analysed using the eosin-nigrosin staining. Our results revealed the dose- and time-dependent effect of kanamycin under the in vitro conditions. In conclusion, the selected concentrations of kanamycin may have adverse effects on the motility, mitochondrial activity, acrosomal and membrane integrity during semen processing. Considering the relatively low concentrations used, we do not recommend to use kanamycin as a supplement in bovine semen extenders.


2017 ◽  
Vol 62 (No. 10) ◽  
pp. 435-445 ◽  
Author(s):  
A. Krejcárková ◽  
P. Folková ◽  
O. Šimoník ◽  
M. Šašková ◽  
R. Krejčířová ◽  
...  

Genistein (GEN) and zearalenone (ZEA), environmental oestrogens commonly present in feedstuff for pigs, are known for their effects on reproductive functions. The aim was to verify the in vitro effects of 0.5–20 µM concentrations of GEN, ZEA and its metabolite α-zearalenol (α-ZOL) on pig sperm motility. A dose-dependent increase of the immotile sperm amount against fast and medium-fast sperm clusters was observed with all three oestrogens from the lowest concentrations tested. Individual CASA (computer-assisted sperm analysis) parameters of motile sperms seemed to be less sensitive indicators. This should be considered especially in toxicological research on a sperm model. Background of inconsistencies in to date-published papers is discussed. The results shift the effective concentrations of ZEA, α-ZOL, and GEN to values achievable in vivo and raises the questions of risk assessment of these compounds in pig reproduction.


Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1037
Author(s):  
Yena Jung ◽  
Hyewon Bang ◽  
Young-Hyun Kim ◽  
Na-Eun Park ◽  
Young-Ho Park ◽  
...  

To elucidate the functional role of V-set and immunoglobulin domain-containing 1 (VSIG1) in spermatogenesis and fertilization, we knocked out (KO) VSIG1 in a mouse embryo using CRISPR/Cas9 (Clustered regularly interspaced short palindromic repeat/CRISPR-associated protein 9) -mediated genome editing. Reverse transcription PCR was performed using cDNA synthesized from VSIG1 KO testis RNA. Although Western blot analysis using a specific antibody to VSIG1 confirmed VSIG1 protein defects in the KO mice, hematoxylin-eosin staining analysis was similar in the KO and wild-type mice. Additionally, computer-assisted sperm analysis and in vitro fertilization experiments were conducted to confirm the activity and fertilization ability of sperm derived from the KO mouse. Mice lacking VSIG1 were viable and had no serious developmental defects. As they got older, the KO mice showed slightly higher weight loss, male mice lacking VSIG1 had functional testes, including normal sperm number and motility, and both male and female mice lacking VSIG1 were fertile. Our results from VSIG1 KO mice suggest that VSIG1 may not play essential roles in spermatogenesis and normal testis development, function, and maintenance. VSIG1 in sperm is dispensable for spermatogenesis and male fertility in mice. As several genes are known to possess slightly different functions depending on the species, the importance and molecular mechanism of VSIG1 in tissues of other species needs further investigation.


2019 ◽  
Author(s):  
CF Hung ◽  
S Holton ◽  
YH Chow ◽  
WC Liles ◽  
SA Gharib ◽  
...  

AbstractBackgroundWe previously reported on the role of pericyte-like cells as functional sentinel immune cells in lung injury. However, much about the biological role of pericytes in lung injury remains unknown. Lung pericyte-like cells are well-positioned to sense disruption to the epithelial barrier and coordinate local inflammatory responses due to their anatomic niche within the alveoli. In this report, we characterized transcriptional responses and functional changes in pericyte-like cells following activation by alveolar components from injured and uninjured lungs in a mouse model of acute lung injury (ALI).MethodsWe purified pericyte-like cells from lung digests using PDGFRβ as a selection marker and expanded them in culture as previously described (1). We induced sterile acute lung injury in mice with recombinant human Fas ligand (rhFasL) instillation followed by mechanical ventilation (1). We then collected bronchoalveolar lavage fluid (BALF) from injured and uninjured mice. Purified pericyte-like cells in culture were exposed to growth media only (control), BALF from uninjured mice, and BALF from injured mice for 6 and 24 h. RNA collected from these treatment conditions were processed for RNAseq. Targets of interest identified by pathway analysis were validated using in vitro and in vivo assays.ResultsWe observed robust global transcriptional changes in pericyte-like cells following treatment with uninjured and injured BALF at 6 h, but this response persisted for 24 h only after exposure to injured BALF. Functional enrichment analysis of pericytes treated with injured BALF revealed activation of immuno-inflammatory, cell migration and angiogenesis-related pathways, whereas processes associated with tissue development and remodeling were down-regulated. We validated select targets in the inflammatory, angiogenesis-related, and cell migratory pathways using functional biological assays in vitro and in vivo.ConclusionLung pericyte-like cells are highly responsive to alveolar compartment content from both uninjured and injured lungs, but injured BALF elicits a more sustained response. The inflammatory, angiogenic, and migratory changes exhibited by activated pericyte-like cells underscore the phenotypic plasticity of these specialized stromal cells in the setting of acute lung injury.


2021 ◽  
Vol 8 ◽  
Author(s):  
Fenglei Gao ◽  
Ping Wang ◽  
Kai Wang ◽  
Yushan Fan ◽  
Yuming Chen ◽  
...  

The proteins in the seminal plasma and on the sperm surface play important roles in sperm function and numerous reproductive processes. The cysteine-rich secretory proteins (CRISPs) are enriched biasedly in the male reproductive tract of mammals, and CRISP2 is the sole member of CRISPs produced during spermatogenesis; whereas the role of CRISP2 in fertilization and its association with fertility of boars are still unclear. This study aimed to investigate the relationship between the sperm CRISP2 and boar fertility, and explore its impact sperm fertilizing ability. The levels of CRISP2 protein in sperm were quantified by ELISA; correlation analysis was performed to evaluate the association between CRISP2 protein levels and boar reproductive parameters. Meanwhile, the expression of CRISP2 in boar reproductive organs and sperm, and the effects of CRISP2 on in vitro fertilization (IVF) were examined. The results showed that boars with high sperm levels of CRISP2 had high fertility. The protein levels of CRISP2 in sperm were positively correlated with the litter size (r = 0.412, p = 0.026), the number of live-born piglets (r = 0.421, p = 0.023) and the qualified piglets per litter (r = 0.381, p = 0.042). CRISP2 is specifically expressed in the testis and sperm of adult boars, and its location on sperm changed mainly from the post-acrosomal region to the apical segment of acrosome during capacitation. The cleavage rate was significantly decreased by adding the anti-CRISP2 antibody to the IVF medium, which indicates CRISP2 plays a critical role in fertilization. In conclusion, CRISP2 protein is specifically expressed in the adult testis and sperm and is associated with sperm fertilizing ability and boar fertility. Further mechanistic studies are warranted, in order to fully decipher the role of CRISP2 in the boar reproduction.


2021 ◽  
Author(s):  
Silvia Tiberti ◽  
Carlotta Catozzi ◽  
Caterina Scirgolea ◽  
Ottavio Croci ◽  
Mattia Ballerini ◽  
...  

Tumor contexture has emerged as a major determinant to establish prognosis and guide novel therapies and tumor infiltrating CD8+ T cells have been associated with a better prognosis in several solid tumors, including early-stage colorectal cancer (CRC). However, the tumor immune infiltrate is highly heterogeneous and understanding how the interplay between different immune cell compartments impacts on the clinical outcome is still in its infancy. Here, we describe in a prospective cohort a novel CD8+ T effector memory population, which is characterized by high levels of Granzyme K (GZMKhigh CD8+ TEM) and correlated with CD15high tumor infiltrating neutrophils. We provide both in vitro and in vivo evidence of the role of stromal cell-derived factor 1 (CXCL12/SDF-1) in driving functional changes on neutrophils at the tumor site, promoting their retention and increasing crosstalk with CD8+ T cells. Mechanistically, as a consequence of the interaction with neutrophils, CD8+ T cells are skewed towards a CD8+ TEM phenotype, producing high levels of GZMK, which in turn decreased E-cadherin pathway. The correlation of GZMKhigh CD8+ TEM and neutrophils with both tumor progression in mice and early relapse in CRC patients demonstrate the role of GZMKhigh CD8+ TEM in promoting malignancy. Indeed, a gene signature defining GZMKhigh CD8+ TEM was associated with worse prognosis on a larger independent cohort of CRC patients and a similar analysis was extended to lung cancer (TCGA). Overall, our results highlight the emergence of GZMKhigh CD8+ TEM in early-stage CRC tumors as a hallmark driven by the interaction with neutrophils, which could implement current patient stratification and be targeted by novel therapeutics.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10847
Author(s):  
Yangyang Wu ◽  
Ting Wang ◽  
Zigao Zhao ◽  
Siyu Liu ◽  
Cong Shen ◽  
...  

Background Retinoic Acid Induced Protein 14 (Rai14) is an evolutionarily conserved gene that is highly expressed in the testis. Previous experiments have reported that small interfering RNA (siRNA)-mediated gene knockdown (KD) of Rai14 in rat testis disrupted spermatid polarity and transport. Of note, a gene knockout (KO) model is considered the “gold standard” for in vivo assessment of crucial gene functions. Herein, we used CRISPR/Cas9-based gene editing to investigate the in vivo role of Rai14 in mouse testis. Methods Sperm concentration and motility were assayed using a computer-assisted sperm analysis (CASA) system. Histological and immunofluorescence (IF) staining and transmission electron microscopy (TEM) were used to visualize the effects of Rai14 KO in the testes and epididymides. Terminal deoxynucleotidyl transferase-dUTP nick-end labeling (TUNEL) was used to determine apoptotic cells. Gene transcript levels were calculated by real-time quantitative PCR. Results Rai14 KO in mice depicted normal fertility and complete spermatogenesis, which is in sharp contrast with the results reported previously in a Rai14 KD rat model. Sperm parameters and cellular apoptosis did not appear to differ between wild-type (WT) and KO group. Mechanistically, in contrast to the well-known role of Rai14 in modulating the dynamics of F-actin at the ectoplasmic specialization (ES) junction in the testis, morphological changes of ES junction exhibited no differences between Rai14 KO and WT testes. Moreover, the F-actin surrounded at the ES junction was also comparable between the two groups. Conclusion In summary, our study demonstrates that Rai14 is dispensable for mouse spermatogenesis and fertility. Although the results of this study were negative, the phenotypic information obtained herein provide an enhanced understanding of the role of Rai14 in the testis, and researchers may refer to these results to avoid conducting redundant experiments.


Author(s):  
Ludmila Curci ◽  
Guillermo Carvajal ◽  
Valeria Sulzyk ◽  
Soledad Natalia Gonzalez ◽  
Patricia S. Cuasnicú

Cation channel of sperm (CatSper), the main sperm-specific Ca2+ channel, plays a key role in mammalian fertilization, and it is essential for male fertility, becoming an attractive target for contraception. Based on this, in the present work, we investigated the effects of CatSper inactivation on in vitro and in vivo sperm fertilizing ability and the mechanisms underlying such effects. Exposure of cauda epididymal mouse sperm to different concentrations (1–20 μM) of the potent CatSper inhibitor HC-056456 (HC) during in vitro capacitation showed no effects on sperm viability but significantly affected Ca2+ entry into the cells, progressive motility, protein tyrosine phosphorylation, induced acrosome reaction, and hyperactivation, as well as the sperm’s ability to in vitro fertilize cumulus oocyte complexes and zona-free eggs. Whereas the presence of HC during gamete coincubation did not affect in vitro fertilization, exposure of either non-capacitating or already capacitated sperm to HC prior to gamete coincubation severely reduced fertilization, indicating that sperm function is affected by HC when the cells are incubated with the drug before sperm–egg interaction. Of note, insemination of HC-treated sperm into the uterus significantly or completely reduced the percentage of oviductal fertilized eggs showing, for the first time, the effects of a CatSper inhibitor on in vivo fertilization. These observations, together with the finding that HC affects sperm fertilizing ability independently of the sperm capacitation status, provide further insights on how CatSper regulates sperm function and represent a solid proof of concept for developing a male/female non-hormonal contraceptive based on the pharmacological blockage of CatSper activity.


2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.


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