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Biology of Reproduction Dec 2022Methods for standard in vitro fertilization have been difficult to establish in the horse. We evaluated whether prolonged sperm pre-incubation would support subsequent...
Methods for standard in vitro fertilization have been difficult to establish in the horse. We evaluated whether prolonged sperm pre-incubation would support subsequent fertilization. Fresh sperm were pre-incubated with penicillamine, hypotaurine, and epinephrine (PHE) for 22 h. Co-incubation of cumulus-oocyte complexes (COCs) for 6 h yielded 43% fertilization; culture of presumptive embryos yielded 21% blastocysts. Sperm incubated similarly, but without PHE, did not fertilize oocytes. Use of extended semen in the system yielded 54% blastocysts and was applied in subsequent experiments. Transfer of three in vitro fertilization-produced blastocysts to recipient mares resulted in birth of three normal foals. When sperm were pre-incubated for 22 h, 47-79% of oocytes were fertilized after 1 h of co-incubation. Sperm pre-incubated for 15 min or 6 h before co-incubation yielded no fertilization at 1 h, suggesting that capacitation in this system requires between 6 and 22 h. Sperm assessed after 15 min, 6 h, or 22 h pre-incubation showed increasing protein tyrosine phosphorylation of the midpiece, equatorial band, and apical head; this pattern differed from that induced by high pH conditions and may denote functional equine sperm capacitation. Use of the final devised system, i.e., extended semen, with 22 h of sperm pre-incubation and 3 h of COC co-incubation, yielded 90% fertilization with a blastocyst rate of 74%. This is the first report of efficient and repeatable standard in vitro fertilization in the horse and the first report of in vitro production of blastocysts and resulting foals after in vitro fertilization.
Topics: Horses; Animals; Female; Male; Semen; Fertilization in Vitro; Spermatozoa; Blastocyst; Sperm Capacitation; Oocytes; Penicillamine; Epinephrine
PubMed: 36106756
DOI: 10.1093/biolre/ioac172 -
Frontiers in Cell and Developmental... 2022In mammals, sperm acquire fertilization ability after a series of physiological and biochemical changes, collectively known as capacitation, that occur inside the female...
In mammals, sperm acquire fertilization ability after a series of physiological and biochemical changes, collectively known as capacitation, that occur inside the female reproductive tract. In addition to other requirements, sperm bioenergetic metabolism has been identified as a fundamental component in the acquisition of capacitation. Mammalian sperm produce ATP through two main metabolic processes, oxidative phosphorylation (OXPHOS) and aerobic glycolysis that are localized to two different flagellar compartments, the midpiece, and the principal piece, respectively. In mouse sperm, the occurrence of many events associated with capacitation relies on the activity of these two energy-producing pathways, leading to the hypothesis that some of these events may impose changes in sperm energetic demands. In the present study, we used extracellular flux analysis to evaluate changes in glycolytic and respiratory parameters of murine sperm that occur as a consequence of capacitation. Furthermore, we examined whether these variations affect sperm ATP sustainability. Our results show that capacitation promotes a shift in the usage ratio of the two main metabolic pathways, from oxidative to glycolytic. However, this metabolic rewiring does not seem to affect the rate at which the sperm consume ATP. We conclude that the probable function of the metabolic switch is to increase the ATP supply in the distal flagellar regions, thus sustaining the energetic demands that arise from capacitation.
PubMed: 36081906
DOI: 10.3389/fcell.2022.950979 -
International Journal of Molecular... Aug 2022Glutathione peroxidase 4 (Gpx4) and arachidonic acid 15 lipoxygenase (Alox15) are counterplayers in oxidative lipid metabolism and both enzymes have been implicated in...
Glutathione peroxidase 4 (Gpx4) and arachidonic acid 15 lipoxygenase (Alox15) are counterplayers in oxidative lipid metabolism and both enzymes have been implicated in spermatogenesis. However, the roles of the two proteins in acrosomal exocytosis have not been explored in detail. Here we characterized Gpx4 distribution in mouse sperm and detected the enzyme not only in the midpiece of the resting sperm but also at the anterior region of the head, where the acrosome is localized. During sperm capacitation, Gpx4 translocated to the post-acrosomal compartment. Sperm from Gpx4 mice heterozygously expressing a catalytically silent enzyme displayed an increased expression of phosphotyrosyl proteins, impaired acrosomal exocytosis after in vitro capacitation and were not suitable for in vitro fertilization. Alox15-deficient sperm showed normal acrosome reactions but when crossed into a Gpx4-deficient background spontaneous acrosomal exocytosis was observed during capacitation and these cells were even less suitable for in vitro fertilization. Taken together, our data indicate that heterozygous expression of a catalytically silent Gpx4 variant impairs acrosomal exocytosis and in vitro fertilization. Alox15 deficiency hardly impacted the acrosome reaction but when crossed into the Gpx4-deficient background spontaneous acrosomal exocytosis was induced. The detailed molecular mechanisms for the observed effects may be related to the compromised redox homeostasis.
Topics: Acrosome; Acrosome Reaction; Animals; Arachidonate 15-Lipoxygenase; Exocytosis; Fertilization in Vitro; Male; Mice; Phospholipid Hydroperoxide Glutathione Peroxidase; Semen; Spermatozoa
PubMed: 36077303
DOI: 10.3390/ijms23179907 -
The World Journal of Men's Health Jan 2023To clarify (phospho-) glycogen synthase kinase-3 (GSK3) isoform variants in the germline and soma of human testes and spermatozoa.
PURPOSE
To clarify (phospho-) glycogen synthase kinase-3 (GSK3) isoform variants in the germline and soma of human testes and spermatozoa.
MATERIALS AND METHODS
GSK3 isoform variants in normospermatogenic and Sertoli cell-only (SCO) testicular biopsies and spermatozoa were examined.
RESULTS
In normospermatogenic testes, GSK3α and GSK3β variants 1 and 2 different in low complexity region (LCR) were expressed and their levels were decreased in SCO testes. β variant 3 was only expressed in SCO testes. GSK3β as well as GSK3α, the dominant isoforms in testes were decreased in SCO testes. In normospermatogenic testes, GSK3β were found in spermatogonia and markedly decreased in meiotic germ cells in which GSK3α was dominant. p-GSK3α/β were marginal in spermatogonia and early spermatocytes. In SCO testes, GSK3α/β immunoreactivity in seminiferous epithelia was weaker than those of normospermatogenic testes whereas p-GSK3α/β(Ser) immunoreactivity was visibly increased in Sertoli cells. GSK3α was dominant in ejaculated spermatozoa in which GSK3α and p-GSK3α(Ser) were found in the head, midpiece, and tail. In acrosome-reacted spermatozoa, GSK3α was found in the equatorial region of head, midpiece, and tail, and p-GSK3α(Ser) was only found in midpiece. During sperm capacitation, p-GSK3α(Ser) was significantly increased together with phosphotyrosine proteins and motility.
CONCLUSIONS
In human male germ cells, GSK3 isoforms different in LCRs switch from GSK3β to GSK3α during meiotic entry, suggesting the isoform-specific roles of GSK3α and GSK3β in meiosis and stemness or proliferation of spermatogonia, respectively. In dormant Sertoli cells of SCO testes kinase activity of GSK3 might be downregulated via inhibitory phosphorylation. In spermatozoa, inhibitory phosphorylation of GSK3α might be coupled with activation of motility during capacitation.
PubMed: 36047078
DOI: 10.5534/wjmh.220108 -
Scientific Reports Aug 2022Aucubin (AU) is one of the widespread compounds belonging to the group of iridoid glycosides, which possesses numerous beneficial properties. Nonylphenol (NP), is a...
Aucubin (AU) is one of the widespread compounds belonging to the group of iridoid glycosides, which possesses numerous beneficial properties. Nonylphenol (NP), is a synthetic environmental toxicant that has the potential to cause male infertility through excessive production of reactive oxygen species. In the current study, the remedial potential of Aucubin was assessed against NP-generated testicular damage in male rats. Animals were distributed into four groups and treated for 56 days in this study. Control-group (0.1% DMSO + food), NP group (100 µg/kg), NP + AU group (100 µg/kg + 5 mg/kg) and AU group (5 mg/kg). NP exposure significantly (p < 0.05) reduced the activity of antioxidant enzymes i.e., glutathione reductase, catalase (CAT), superoxide dismutase, glutathione peroxidase (GPx), and total protein content (TPC), whereas the level of reactive oxygen species (ROS) and thiobarbituric acid reactive substances (TBARS) was enhanced substantially (p < 0.05). Treatment with AU substantially (p < 0.05) recovered activities of antioxidant enzymes, TPC, ROS, and TBARS levels. Moreover, decrease in the levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), plasma testosterone, sperm count, motility, sperm membrane integrity, and the number of spermatocytes of different stages along with the level of steroidogenic enzymes i.e., 17β-hydroxysteroid dehydrogenase (17β-HSD), 3β-hydroxysteroid dehydrogenase (3β-HSD), and B-cell lymphoma 2 (Bcl-2) by NP administration were recovered to control values by AU treatment. However, AU mitigated the sperm abnormalities (head/midpiece/tail), the number of dead sperms, and proapoptotic proteins i.e., Bcl-2 associated X protein (Bax), caspase-9, and caspase-3 that were increased by NP. Besides, AU treatment recovered the NP-induced potential histopathological alterations in the testicular tissues such as the height of epithelium, seminiferous tubules diameter as well as the height of tunica propria. Overall, NP-induced toxicity was effectively recuperated by the AU administration. These results indicate that AU might be considered as a potential protective agent against testicular damage. The observed protection may be due to its antioxidant, anti-apoptotic, anti-inflammatory and androgenic potential.
Topics: Animals; Antioxidants; Glycosides; Iridoid Glucosides; Iridoids; Male; Oxidative Stress; Phenols; Proto-Oncogene Proteins c-bcl-2; Rats; Reactive Oxygen Species; Semen; Testis; Testosterone; Thiobarbituric Acid Reactive Substances
PubMed: 35962184
DOI: 10.1038/s41598-022-18148-1 -
International Journal of Molecular... Jul 2022The sperm flagellum is essential for male fertility. Multiple morphological abnormalities of the sperm flagella (MMAF) is a severe form of asthenoteratozoospermia. MMAF...
The sperm flagellum is essential for male fertility. Multiple morphological abnormalities of the sperm flagella (MMAF) is a severe form of asthenoteratozoospermia. MMAF phenotypes are understood to result from pathogenic variants of genes from multiple families including AKAP, DANI, DNAH, RSPH, CCDC, CFAP, TTC, and LRRC, among others. The Leucine-rich repeat protein (LRRC) family includes two members reported to cause MMAF phenotypes: and . Despite vigorous research towards understanding the pathogenesis of MMAF-related diseases, many genes remain unknown underlying the flagellum biogenesis. Here, we found that Leucine-rich repeat containing 46 (LRRC46) is specifically expressed in the testes of adult mice, and show that LRRC46 is essential for sperm flagellum biogenesis. Both scanning electron microscopy (SEM) and Papanicolaou staining (PS) presents that the knockout of in mice resulted in typical MMAF phenotypes, including sperm with short, coiled, and irregular flagella. The male KO mice had reduced total sperm counts, impaired sperm motility, and were completely infertile. No reproductive phenotypes were detected in female mice. Immunofluorescence (IF) assays showed that LRRC46 was present throughout the entire flagella of control sperm, albeit with evident concentration at the mid-piece. Transmission electron microscopy (TEM) demonstrated striking flagellar defects with axonemal and mitochondrial sheath malformations. About the important part of the Materials and Methods, SEM and PS were used to observe the typical MMAF-related irregular flagella morphological phenotypes, TEM was used to further inspect the sperm flagellum defects in ultrastructure, and IF was chosen to confirm the location of protein. Our study suggests that LRRC46 is an essential protein for sperm flagellum biogenesis, and its mutations might be associated with MMAF that causes male infertility. Thus, our study provides insights for understanding developmental processes underlying sperm flagellum formation and contribute to further observe the pathogenic genes that cause male infertility.
Topics: Abnormalities, Multiple; Animals; Female; Fertility; Flagella; Humans; Infertility, Male; Male; Mice; Mutation; Proteins; Semen; Sperm Motility; Sperm Tail; Spermatogenesis; Spermatozoa; Exome Sequencing
PubMed: 35955660
DOI: 10.3390/ijms23158525 -
Theriogenology Sep 2022The expression of aquaglyceroporin 3 (AQP-3) has been demonstrated in the spermatozoa of several mammalian species and its role has been associated with cryotolerance....
The expression of aquaglyceroporin 3 (AQP-3) has been demonstrated in the spermatozoa of several mammalian species and its role has been associated with cryotolerance. Post-thaw sperm quality from individual dromedary males with different response to freezing-thawing process was evaluated through sperm head morphometry. In order to understand the cellular mechanisms affected by cryoinjury we have explored the presence and distribution of sperm AQP-3 using western blotting and immunocytochemistry. WB showed different intensity of the specific signal bands at 28 kDa. Immunofluorescence assessments allowed us to identify five different and clear AQP-3 distribution patterns of labelling in the sperm plasma membrane; acrosome, post-acrosome, mid-piece, and principal and final tail. Although expression of AQP-3 varied among male ejaculates, the individual sperm response to freeze-thawing was not associated with AQP-3 expression. Thus, AQP3 expressions do not seem like a reliable predictor of sperm response to freeze-thawing process in this species. This work is the first to describe the morphometric characteristics of the heads of dromedary spermatozoa. No correlation was found between sperm head dimensions and sperm quality variables after freeze-thawing suggesting that dromedary camel sperm head morphometry is also not a reliable predictor of cryosurvival.
Topics: Animals; Aquaporin 3; Camelus; Cryopreservation; Male; Semen Preservation; Sperm Head; Sperm Motility; Spermatozoa
PubMed: 35797755
DOI: 10.1016/j.theriogenology.2022.06.029 -
Toxicology Research Jun 2022Male reproductive damage is one of the most adverse side effects of doxorubicin (DOX). Isorhamnetin is a natural flavonoid, which displays remarkable antioxidant...
BACKGROUND
Male reproductive damage is one of the most adverse side effects of doxorubicin (DOX). Isorhamnetin is a natural flavonoid, which displays remarkable antioxidant potential.
OBJECTIVE
The current research was designed to assess the protective effects of Isorhamnetin against DOX-instigated testicular damages.
METHODS
Adult male Wistar rats (n=32) were divided into 4 groups: control, DOX (3 mg/kg i.p. 3 doses each after 1 week), DOX + Isorhamnetin (3 mg/kg 3 doses each after 1 week +10 mg/kg i.p. daily for 28 days, respectively), and Isorhamnetin (10 mg/kg i.p. per day). After 28 days of treatment, biochemical, spermatogenic, steroidogenic, hormonal, proapoptotic, antiapoptotic, and histopathological parameters were estimated.
RESULTS
DOX exposure significantly decreased the activity of acid phosphatase, lactate dehydrogenase, and gamma-glutamyl transferase. Furthermore, DOX substantially decreased the activities of antioxidant enzymes, i.e. catalase, superoxide dismutase, glutathione reductase, and glutathione peroxidase along with protein content, whereas it increased the malondialdehyde level. It also reduced sperm progressive motility, viability, the number of hypoosmotic tail swelled spermatozoa, and epididymis sperm count and increased the sperm morphological anomalies (head, midpiece, and tail). Besides, it decreased the levels of follicle-stimulating hormone, luteinizing hormone, and plasma testosterone and lowered the expression of steroidogenic enzymes (3β-hydroxysteroid dehydrogenase, 17β-hydroxysteroid dehydrogenase, and steroidogenic acute regulatory protein) and testicular antiapoptotic marker (B-cell lymphoma 2) but increased the expression of proapoptotic markers (BCL2-associated X protein and caspase-3) along with histopathological impairments. However, isorhamnetin prevented all the damages caused by DOX.
CONCLUSION
Conclusively, Isorhamnetin can be used as a powerful mitigating agent to avert DOX-induced testicular damages.
PubMed: 35782651
DOI: 10.1093/toxres/tfac024 -
International Journal of Molecular... Mar 2022Angiotensin-converting enzyme 2 (ACE2) is a protein widely expressed in numerous cell types, with different biological roles mainly related to the renin-angiotensin...
Angiotensin-converting enzyme 2 (ACE2) is a protein widely expressed in numerous cell types, with different biological roles mainly related to the renin-angiotensin system. Recently, ACE2 has been in the spotlight due to its involvement in the SARS-CoV-2 entry into cells. There are no data available regarding the expression of ACE2 and its short-ACE2 isoform at the protein level on human spermatozoa. Here, protein expression was demonstrated by western blot and the percentage of sperm displaying surface ACE2 was assessed by flow cytometry. Immunocytochemistry assays showed that full-length ACE2 was mainly expressed in sperm midpiece, while short ACE2 was preferentially distributed on the equatorial and post-acrosomal region of the sperm head. To our knowledge, this is the first study demonstrating the expression of protein ACE2 on spermatozoa. Further studies are warranted to determine the role of ACE2 isoforms in male reproduction.
Topics: Angiotensin-Converting Enzyme 2; COVID-19; Humans; Male; Protein Isoforms; SARS-CoV-2; Spermatozoa
PubMed: 35409054
DOI: 10.3390/ijms23073694 -
The Journal of Experimental Biology May 2022Sperm traits can influence fertilisation success, but there is still much we do not understand about sperm condition dependence, that is, how much sperm traits depend on...
Sperm traits can influence fertilisation success, but there is still much we do not understand about sperm condition dependence, that is, how much sperm traits depend on the male's energy acquisition and allocation. This is especially pronounced in avian taxa, despite extensive observational studies and sampling in wild populations. In this study, we collected sperm samples before and after experimentally reducing diet quality of wild-derived captive zebra finches in small mixed-sex groups, which we compared with individuals on a control diet. We measured the length of sperm components (head, midpiece, flagellum and total sperm length), the proportion of sperm with normal morphology, the proportion of sperm that were progressively motile and sperm swimming velocity (curvilinear velocity; VCL). The only sperm trait we found to be impacted by reduced diet quality was a significant decrease in sperm midpiece length. This is consistent with emerging evidence in other non-model systems, as well the fact that diet can alter mitochondrial density and structure in other tissue types. There was also a significant decrease in sperm velocity and the proportion of motile sperm over the course of the experiment for both experimental groups (i.e. unrelated to diet). This decrease in sperm velocity with largely unchanged sperm morphology emphasizes that there are other important determinants of sperm velocity, likely including seminal fluid composition.
Topics: Animals; Diet; Finches; Flagella; Male; Sperm Motility; Spermatozoa
PubMed: 35403680
DOI: 10.1242/jeb.243715