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Fertility and Sterility Apr 2023To obtain de novo male gametes capable of inducing full preimplantation blastocyst development using a novel three-dimensional (3D) culture system.
OBJECTIVE
To obtain de novo male gametes capable of inducing full preimplantation blastocyst development using a novel three-dimensional (3D) culture system.
DESIGN
Mouse embryonic stem cells (mESCs) were spherified by plunging in sodium alginate followed by calcium chloride, delineating a 3D environment that simulates the seminiferous tubule. As a control, mESCs cultured on two-dimensional plates were used. Plates and spheres containing mESCs from both methods were exposed to Activin-A, bFGF, and KSR followed by exposure to BMP4, LIF, SCF, and EGF to promote differentiation into male germ-like cells.
MAIN OUTCOME MEASURES
Cells were assessed for VASA, DAZL, and BOULE on days 3 and 10. Cells were later injected into activated oocytes and monitored using time-lapse imaging on days 15, 22, 29, and 36. Control conceptuses generated using mature epididymal spermatozoa were also monitored via time-lapse imaging.
RESULTS
On day 3, cells differentiated on plates expressed VASA at 1% and DAZL at 29%. In spheres, VASA was expressed at a rate of 15% and DAZL at a rate of 45% (P<.001). On day 10, cells differentiated on plates had VASA expression of 7%, DAZL of 23%, and BOULE of only 0.5%. Cells differentiated into spheres expressed VASA at a rate of 20%, DAZL at 43%, and BOULE at 10% (P<.001). Subsequent differentiation in spheres on day 3 exhibited a DAZL (expressed in spermatogonia) expression of 43% and a VASA (further spermatogenesis progression) expression of 15%. On day 10, DAZL and VASA expressions were reassessed and increased to 45% and 18%, respectively. BOULE, a marker expressed solely in postmeiotic spermatocytes, was expressed at 8%, whereas acrosin was expressed in spermatids at 2%. On day 15, VASA expression plateaued at 17%, BOULE peaked at 10%, and acrosin reached 5%. On day 22, expression of VASA increased to 19%, BOULE decreased to 8%, and acrosin peaked at 7%. On day 29, VASA expression peaked at 20%, BOULE dropped to 2%, and acrosin remained stable at 7%. On day 36, VASA expression remained at 13%, whereas BOULE and acrosin expression decreased to 0% and 1%, respectively. The control cohort attained 88.4% fertilization and 76.9% blastocyst rates. De novo gametes achieved fertilization rates of 35.0%, 61.1%, 81.8%, and 50.0% on days 15, 22, 29, and 36, respectively. Neogametes-generated blastocyst rates were 5.0%, 16.7%, 36.4%, and 8.3% for days 15, 22, 29, and 36, respectively.
CONCLUSION
Our novel 3D differentiation model can generate functional gametes and is aimed at obviating the need for allogeneic/xenogeneic transplantation. The decreased overall marker expression and the reduced blastocyst development indicated that intrasphere germ cell differentiation correlated with the length of mouse spermatogenesis at approximately 30 days. Future experiments will be conducted to confirm the reproducibility of our findings and the eventual generation of offspring.
Topics: Male; Animals; Mice; Acrosin; Haploidy; Reproducibility of Results; Spermatozoa; Spermatogenesis; Spermatocytes
PubMed: 36706828
DOI: 10.1016/j.fertnstert.2023.01.021 -
Andrologia Feb 2021Mitochondria have multiple functions, including synthesis of adenine triphosphate, production of reactive oxygen species, calcium signalling, thermogenesis and... (Review)
Review
Mitochondria have multiple functions, including synthesis of adenine triphosphate, production of reactive oxygen species, calcium signalling, thermogenesis and apoptosis. Mitochondria have a significant contribution in regulating the various physiological aspects of reproductive function, from spermatogenesis up to fertilisation. Mitochondrial functionality and intact mitochondrial membrane potential are a pre-requisite for sperm motility, hyperactivation, capacitation, acrosin activity, acrosome reaction and DNA integrity. Optimal mitochondrial activity is therefore crucial for human sperm function and semen quality. However, the precise role of mitochondria in spermatozoa remains to be fully explored. Defects in sperm mitochondrial function severely impair the maintenance of energy production required for sperm motility and may be an underlying cause of asthenozoospermia. Sperm mtDNA is susceptible to oxidative damage and mutations that could compromise sperm function leading to infertility. Males with abnormal semen parameters have increased mtDNA copy number and reduced mtDNA integrity. This review discusses the role of mitochondria in sperm function, along with the causes and impact of its dysfunction on male fertility. Greater understanding of sperm mitochondrial function and its correlation with sperm quality could provide further insights into their contribution in the assessment of the infertile male.
Topics: DNA, Mitochondrial; Humans; Infertility, Male; Male; Mitochondria; Semen Analysis; Sperm Motility; Spermatozoa
PubMed: 32510691
DOI: 10.1111/and.13666 -
Andrology Oct 2023Previously, we reported that cysteine-rich secretory protein 2 is involved in high molecular weight complexes in boar spermatozoa. These cysteine-rich secretory protein...
BACKGROUND
Previously, we reported that cysteine-rich secretory protein 2 is involved in high molecular weight complexes in boar spermatozoa. These cysteine-rich secretory protein 2protein complexes are formed at the last phase of sperm formation in the testis and play a role in sperm shaping and functioning.
OBJECTIVES
This study aimed to identify cysteine-rich secretory protein 2 interacting partners. These binding partner interactions were investigated under different conditions, namely, non-capacitating conditions, after the induction of in vitro sperm capacitation and subsequently during an ionophore A23187-induced acrosome reaction.
MATERIALS AND METHODS
The incubated pig sperm samples were subjected to protein extraction. Extracted proteins were subjected to blue native gel electrophoresis and native immunoblots. Immunoreactive gel bands were excised and subjected to liquid chromatography-mass spectrometry (LC-MS) analysis for protein identification. Protein extracts were also subjected to CRISP2 immunoprecipitation and analyzed by LC-MS for protein identification. The most prominent cystein-rich secretory protein 2 interacting proteins that appeared in both independent LC-MS analyses were studied with a functional in situ proximity interaction assay to validate their property to interact with cystein-rich secretory protein 2 in pig sperm.
RESULTS
Blue native gel electrophoresis and native immunoblots revealed that cystein-rich secretory protein 2 was present within a ∼150 kDa protein complex under all three conditions. Interrogation of cystein-rich secretory-protein 2-immunoreactive bands from blue native gels as well as cystein-rich secretory protein 2 immunoprecipitated products using mass spectrometry consistently revealed that, beyond cystein-rich secretory protein 2, acrosin and acrosin binding protein were among the most abundant interacting proteins and did interact under all three conditions. Co-immunoprecipitation and immunoblotting indicated that cystein-rich secretory protein 2 interacted with pro-acrosin (∼53 kDa) and Aacrosin binding protein under all three conditions and additionally to acrosin (∼35 kDa) after capacitation and the acrosome reaction. The colocalization of these interacting proteins with cystein-rich secretory protein 2 was assessed via in situ proximity ligation assays. The colocalization signal of cystein-rich secretory protein 2 and acrosin in the acrosome seemed dispersed after capacitation but was consistently present in the sperm tail under all conditions. The fluorescent foci of cystein-rich secretory protein 2 and acrsin binding protein colocalization appeared to be redistributed within the sperm head from the anterior acrosome to the post-acrosomal sheath region upon capacitation.
DISCUSSION AND CONCLUSION
These results suggest that CRISP2 may act as a scaffold for protein complex formation and dissociation to ensure the correct positioning of proteins required for the acrosome reaction and zona pellucida penetration.
Topics: Male; Animals; Swine; Acrosin; Cysteine; Semen; Spermatozoa; Proteins; Acrosome; Sperm Capacitation; Protein Binding
PubMed: 36815564
DOI: 10.1111/andr.13413 -
Biomolecules Sep 2023The global trend of rising (male) infertility is concerning, and the unidentifiable causes in half of the cases, the so-called unknown origin male infertility (UOMI),...
The global trend of rising (male) infertility is concerning, and the unidentifiable causes in half of the cases, the so-called unknown origin male infertility (UOMI), demands a better understanding and assessment of both external/internal factors and mechanisms potentially involved. In this work, it was our aim to obtain new insight on UOMI, specifically on idiopathic (ID) and Unexplained male infertility (UMI), relying on a detailed evaluation of the male gamete, including functional, metabolic and proteomic aspects. For this purpose, 1114 semen samples, from males in couples seeking infertility treatment, were collected at the Reproductive Medicine Unit from the Centro Hospitalar e Universitário de Coimbra (CHUC), from July 2018-July 2022. Based on the couples' clinical data, seminal/hormonal analysis, and strict eligibility criteria, samples were categorized in 3 groups, control (CTRL), ID and UMI. Lifestyle factors and anxiety/depression symptoms were assessed via survey. Sperm samples were evaluated functionally, mitochondrially and using proteomics. The results of Assisted Reproduction Techniques were assessed whenever available. According to our results, ID patients presented the worst sperm functional profile, while UMI patients were similar to controls. The proteomic analysis revealed 145 differentially expressed proteins, 8 of which were specifically altered in ID and UMI samples. Acrosin (ACRO) and sperm acrosome membrane-associated protein 4 (SACA4) were downregulated in ID patients while laminin subunit beta-2 (LAMB2), mannose 6-phosphate isomerase (MPI), ATP-dependent 6-phosphofructokinase liver type (PFKAL), STAR domain-containing protein 10 (STA10), serotransferrin (TRFE) and exportin-2 (XPO2) were downregulated in UMI patients. Using random forest analysis, SACA4 and LAMB2 were identified as the sperm proteins with a higher chance of distinguishing ID and UMI patients, and their function and expression variation were in accordance with the functional results. No alterations were observed in terms of lifestyle and psychological factors among the 3 groups. These findings obtained in an experimental setting based on 3 well-defined groups of subjects, might help to validate new biomarkers for unknown origin male infertility (ID and UMI) that, in the future, can be used to improve diagnostics and treatments.
Topics: Humans; Male; Semen; Semen Analysis; Proteomics; Spermatozoa; Infertility, Male
PubMed: 37892144
DOI: 10.3390/biom13101462 -
Human Reproduction (Oxford, England) Jun 2023Does a homozygous nonsense mutation in ACR lead to total fertilization failure (TFF) resulting in male infertility in humans?
STUDY QUESTION
Does a homozygous nonsense mutation in ACR lead to total fertilization failure (TFF) resulting in male infertility in humans?
SUMMARY ANSWER
A novel homozygous nonsense mutation of ACR (c.167G>A, p.Trp56X) was identified in two infertile brothers and shown to cause human TFF.
WHAT IS KNOWN ALREADY
ACROSIN, encoded by ACR, is a major acrosomal enzyme expressed only in the acrosome of the sperm head. Inhibition of acrosin prevents sperm penetration of the zona pellucida (ZP) in several species, including humans. Acr-knockout in hamsters causes male infertility with completely blocked fertilization. Of note, there are no reports of ACR mutations associated with TFF in humans.
STUDY DESIGN, SIZE, DURATION
Whole-exome sequencing (WES) was used for the identification of pathogenic genes for male factor TFF in eight involved couples.
PARTICIPANTS/MATERIALS, SETTING, METHODS
Data from eight infertile couples who had experienced TFF during their IVF or ICSI attempts were collected. Functional assays were used to verify the pathogenicity of the potential genetic factors identified by WES. Subzonal insemination (SUZI) and IVF assays were performed to determine the exact pathogenesis of TFF caused by deficiencies in ACROSIN.
MAIN RESULTS AND THE ROLE OF CHANCE
A novel homozygous nonsense mutation in ACR, c.167G>A, p.Trp56X, was identified in two additional primary infertile brothers whose parents were first cousins. This rare mutation caused ACROSIN deficiency and acrosomal ultrastructural defects in the affected sperm. Spermatozoa lacking ACROSIN were unable to penetrate the ZP, rather than hampering sperm binding, disrupting gamete fusion, or preventing oocyte activation. These findings were supported by the fertilization success of SUZI and ICSI attempts, as well as the normal expression of ACTL7A and PLCζ in the mutant sperm, suggesting that ICSI without remedial assisted oocyte activation is an optimal treatment for ARCOSIN-deficient TFF.
LIMITATIONS, REASONS FOR CAUTION
The absence of another independent pedigree to support our argument is a limitation of this study.
WIDER IMPLICATIONS OF THE FINDINGS
The findings expand our understanding of the genes involved in human TFF, providing information for appropriate genetic counseling and fertility guidance for these patients.
STUDY FUNDING/COMPETING INTEREST(S)
This study was supported by the National Natural Science Foundation of China (grant no. 82201803, 81901541, 82271639, and 32000584), University Synergy Innovation Program of Anhui Province (GXXT-2019-044), and the Nonprofit Central Research Institute Fund of the Chinese Academy of Medical Sciences (grant no. 2019PT310002). The authors declare no conflicts of interest.
TRIAL REGISTRATION NUMBER
N/A.
Topics: Animals; Cricetinae; Humans; Male; Acrosin; Zona Pellucida; Codon, Nonsense; Semen; Spermatozoa; Sperm-Ovum Interactions; Infertility, Male
PubMed: 37004249
DOI: 10.1093/humrep/dead059 -
Heliyon Jul 2023Proton pump inhibitors (PPIs) were one of the most commonly used drugs in daily life. The adverse effects of long-term use of PPIs have aroused widespread controversy....
Proton pump inhibitors (PPIs) were one of the most commonly used drugs in daily life. The adverse effects of long-term use of PPIs have aroused widespread controversy. It was of great significance to explore the molecular mechanism of sperm abnormality caused by PPIs. The PPI group was given omeprazole by gavage for 28 days. After the omeprazole intervention, the caudal epididymis was dissected to obtain sperms, and the sperm was counted through the microscope, as the acrosomal integrity was observed through PNA-FITC staining. The expression of aquaporins were detected by immunofluorescence and western blot in the testis, epididymis and spermatozoa. The liver cytochrome enzyme was evaluated by immunohistochemistry and western blot. We detected the serum estrogen level by ELISA, and the level of alanine transaminase (ALT) were detected through microplate method. The sperm count in PPI group was less than control group ( < 0.05), and the sperm acrosin integrity in PPI group was lower than control group ( < 0.05). In the testis, the expression of aquaporin 3 and aquaporin 8 in PPI group was higher than control group ( < 0.05), while the expression of aquaporin 7 was lower than control group ( < 0.05). In the epididymal and sperm, the expression of aquaporin 3 and aquaporin 7 in PPI group was higher than control group ( < 0.05), while the expression of aquaporin 8 in PPI group was lower than control group ( < 0.05). Meanwhile, the liver cytochrome enzyme in PPI group were lower than control group ( < 0.05), and estrogen and ALT in PPI group were higher than control group (p < 0.05). PPI may lead to the up-regulation of estrogen by inhibiting the activity of cytochrome enzyme, and then lead to the dysfunction of sperm parameters and acrosin integrity by affecting aquaporins function.
PubMed: 37539124
DOI: 10.1016/j.heliyon.2023.e17911 -
Cell and Tissue Research Dec 2023Low acrosin activity (LAA) is associated with sperm function anomaly and poor outcomes of in vitro fertilization. In this study, we confirm that 993 semen samples with...
Low acrosin activity (LAA) is associated with sperm function anomaly and poor outcomes of in vitro fertilization. In this study, we confirm that 993 semen samples with LAA had a reduced sperm motility and low in vitro fertilization rate in comparison with 1332 normal controls (NC). Proteomic comparison between 11 LAA and 11 NC sperm samples identified 35 upregulated and 99 downregulated proteins in the LAA group. Indeed, proteomic data showed that acrosome enzymes Spam1 and Acrosin were among the downregulated proteins in the LAA group, which was validated by quantitative PCR and immunefluorescent staining of sperm cells. The KEEG pathway analysis revealed a deficiency of GSH and Gln biosynthesis in LAA sperm cells. Immunofluorescent staining of sperms and quantitative PCR verified downregulation of GLUL and GCLC, the key enzymes for GSH and Gln biosynthesis. Moreover, the results of ELISA assay confirmed low levels of GSH and Gln in LAA sperm cells. Mechanistic studies showed that addition of 10 mM HO to semen samples led to a significant reduction of acrosin activity and sperm motility, most possibly by triggering premature acrosome release. In contrast, the presence of 20 mM GSH blocked the oxidative effects of HO. Since GSH counteracts the oxidative stress and Gln participates in TCA cycling, their deficiency may affect the redox balance as well as energy production of sperm cells. These findings shed new light on the pathological mechanisms of infertility associated with LAA. Male infertility patients could benefit from GSH supplement by improvement of acrosin activity and other sperm functions.
Topics: Humans; Male; Acrosin; Acrosome; Hydrogen Peroxide; Proteins; Proteomics; Semen; Sperm Motility; Spermatozoa
PubMed: 37833433
DOI: 10.1007/s00441-023-03826-x -
Molecular Human Reproduction Mar 2021The encounter of oocyte and sperm is the key event initiating embryonic development in mammals. Crucial functions of this existential interaction are determined by...
The encounter of oocyte and sperm is the key event initiating embryonic development in mammals. Crucial functions of this existential interaction are determined by proteolytic enzymes, such as acrosin, carried in the sperm head acrosome, and ovastacin, stored in the oocyte cortical granules. Ovastacin is released upon fertilisation to cleave the zona pellucida, a glycoprotein matrix surrounding the oocyte. This limited proteolysis hardens the oocyte envelope, and thereby provides a definitive block against polyspermy and protects the developing embryo. On the other hand, acrosin, the renowned and most abundant acrosomal protease, has been thought to enable sperm to penetrate the oocyte envelope. Depending on the species, proteolytic cleavage of the zona pellucida by acrosin is either essential or conducive for fertilisation. However, the specific target cleavage sites and the resulting physiological consequences of this proteolysis remained obscure. Here, we treated native mouse zonae pellucidae with active acrosin and identified two cleavage sites in zona pellucida protein 1 (ZP1), five in ZP2 and one in ZP3 by mass spectrometry. Several of these sites are highly conserved in mammals. Remarkably, limited proteolysis by acrosin leads to zona pellucida remodelling rather than degradation. Thus, acrosin affects both sperm binding and mechanical resilience of the zona pellucida, as assessed by microscopy and nanoindentation measurements, respectively. Furthermore, we ascertained potential regulatory effects of acrosin, via activation of latent pro-ovastacin and inactivation of fetuin-B, a tight binding inhibitor of ovastacin. These results offer novel insights into the complex proteolytic network modifying the extracellular matrix of the mouse oocyte, which might apply also to other species.
Topics: Acrosin; Acrosome; Animals; Male; Mammals; Mice; Proteolysis; Sperm-Ovum Interactions; Spermatozoa; Zona Pellucida; Zona Pellucida Glycoproteins
PubMed: 33779727
DOI: 10.1093/molehr/gaab022 -
Biological Research Oct 2022Xenotransplantation has been primarily performed using fresh donor tissue to study testicular development for about 20 years, and whether the cultured tissue would be a...
BACKGROUND
Xenotransplantation has been primarily performed using fresh donor tissue to study testicular development for about 20 years, and whether the cultured tissue would be a suitable donor is unclear. In this study, we combined testicular culture and xenotransplantation into an integrative model and explored whether immature testicular tissue would survive and continue to develop in this model.
METHODS
In the new integrative model group, the testes of neonatal rats on postnatal day 8 (PND 8) were cultured for 4 days ex vivo and then were transplanted under the dorsal skin of castrated nude mice. The xenografted testes were resected on the 57th day after xenotransplantation and the testes of rats in the control group were harvested on PND 69. The survival state of testicular tissue was evaluated from morphological and functional perspectives including H&E staining, immunohistochemical staining of 8-OH-dG, immunofluorescence staining, TUNEL assay, ultrastructural study, gene expression and protein analysis.
RESULTS
(a) We found that complete spermatogenesis was established in the testes in the new integrative model group. Compared with the control in the same stage, the seminiferous epithelium in some tubules was a bit thinner and there were vacuoles in part of the tubules. Immunofluorescence staining revealed some ACROSIN-positive spermatids were present in seminiferous tubule of xenografted testes. TUNEL detection showed apoptotic cells and most of them were germ cells in the new integrative model group. 8-OH-dG immunohistochemistry showed strongly positive-stained in the seminiferous epithelium after xenotransplantation in comparison with the control group; (b) Compared with the control group, the expressions of FOXA3, DAZL, GFRα1, BOLL, SYCP3, CDC25A, LDHC, CREM and MKI67 in the new integrative model group were significantly elevated (P < 0.05), indicating that the testicular tissue was in an active differentiated and proliferative state; (c) Antioxidant gene detection showed that the expression of Nrf2, Keap1, NQO1 and SOD1 in the new integrative model group was significantly higher than those in the control group (P < 0.05), and DNA methyltransferase gene detection showed that the expression of DNMT3B was significantly elevated as well (P < 0.05).
CONCLUSION
The new integrative model could maintain the viability of immature testicular tissue and sustain the long-term survival in vivo with complete spermatogenesis. However, testicular genes expression was altered, vacuolation and thin seminiferous epithelium were still apparent in this model, manifesting that oxidative damage may contribute to the testicular development lesion and it needs further study in order to optimize this model.
Topics: 8-Hydroxy-2'-Deoxyguanosine; Acrosin; Animals; Antioxidants; Kelch-Like ECH-Associated Protein 1; Male; Methyltransferases; Mice; Mice, Nude; NF-E2-Related Factor 2; Rats; Spermatogenesis; Superoxide Dismutase-1; Testis
PubMed: 36195947
DOI: 10.1186/s40659-022-00398-y -
Asian Journal of Andrology Jan 2024The clinical applications of acrosin activity are limited. We analyzed 61 578 male partners in infertile couples who visited the outpatient department of the...
The clinical applications of acrosin activity are limited. We analyzed 61 578 male partners in infertile couples who visited the outpatient department of the Reproductive and Genetic Hospital of CITIC-Xiangya (Changsha, China) between August 2014 and December 2019 to determine the reference ranges and thresholds for acrosin activity in infertile Chinese men; to determine whether correlations exist between acrosin activity and age, sperm concentration, sperm morphology, or sperm motility; and to evaluate whether acrosin activity could serve as an effective prognostic indicator for choosing between in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) in the clinic. The cut-off value for the normal reference range of acrosin activity for male partners in infertile couples was 24.78 µIU per 10 6 sperm. There was no significant association between acrosin activity and age, sperm concentration, semen volume, total sperm count, progressive motility, or total motile spermatozoa. A weak positive correlation was found between acrosin activity and normal sperm morphology. There was a statistically significant difference in abnormal acrosome morphology between the group with high acrosin activity (>24.78 µIU per 10 6 sperm) and the group with low acrosin activity (<24.78 µIU per 10 6 sperm). The group with a low IVF fertilization rate had a high index of abnormal acrosomal morphology at 21.2%, while the group with a high IVF fertilization rate had a low index of 0.2%. At an acrosin activity of <24.78 µIU per 10 6 sperm, in one cycle of the same patient, the fertilization rate, normal fertilization rate, and good-quality embryo rate for ICSI were significantly higher than those for IVF. Therefore, the most promising application of acrosin activity could be in the selection of ICSI over IVF for infertile male patients with complete fertilization failure or a low fertilization rate.
Topics: Humans; Male; Acrosin; Infertility, Male; Sperm Injections, Intracytoplasmic; Adult; Spermatozoa; Fertilization in Vitro; Sperm Motility; Sperm Count; Female; Semen Analysis; Middle Aged
PubMed: 37695214
DOI: 10.4103/aja202337