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The Journal of Cell Biology Mar 2024Proper compartmentalization of the sperm flagellum is essential for fertility. The annulus is a septin-based ring that demarcates the midpiece (MP) and the principal...
Proper compartmentalization of the sperm flagellum is essential for fertility. The annulus is a septin-based ring that demarcates the midpiece (MP) and the principal piece (PP). It is assembled at the flagellar base, migrates caudally, and halts upon arriving at the PP. However, the mechanisms governing annulus positioning remain unknown. We report that a Chibby3 (Cby3)/Cby1-interacting BAR domain-containing 1 (ciBAR1) complex is required for this process. Ablation of either gene in mice results in male fertility defects, caused by kinked sperm flagella with the annulus mispositioned in the PP. Cby3 and ciBAR1 interact and colocalize to the annulus near the curved membrane invagination at the flagellar pocket. In the absence of Cby3, periannular membranes appear to be deformed, allowing the annulus to migrate over the fibrous sheath into the PP. Collectively, our results suggest that the Cby3/ciBAR1 complex regulates local membrane properties to position the annulus at the MP/PP junction.
Topics: Animals; Male; Mice; Cilia; Cytoskeleton; Semen; Sperm Tail; Spermatogenesis; Nuclear Proteins; Carrier Proteins
PubMed: 38197861
DOI: 10.1083/jcb.202307147 -
BioRxiv : the Preprint Server For... Feb 2024Desmosterol and cholesterol are essential lipid components of the sperm plasma membrane. Cholesterol efflux is required for capacitation, a process through which sperm...
Desmosterol and cholesterol are essential lipid components of the sperm plasma membrane. Cholesterol efflux is required for capacitation, a process through which sperm acquire fertilizing ability. In this study, using a transgenic mouse model overexpressing 24-dehydrocholesterol reductase (DHCR24), an enzyme in the sterol biosynthesis pathway responsible for the conversion of desmosterol to cholesterol, we show that disruption of sterol homeostasis during spermatogenesis led to defective sperm morphology characterized by incomplete mitochondrial packing in the midpiece, reduced sperm count and motility, and a decline in male fertility with increasing paternal age, without changes in body fat composition. Sperm depleted of desmosterol exhibit inefficiency in the acrosome reaction, metabolic dysfunction, and an inability to fertilize the egg. These findings provide molecular insights into sterol homeostasis for sperm capacitation and its impact on male fertility.
PubMed: 38187697
DOI: 10.1101/2023.12.21.572851 -
Environmental Science and Pollution... Feb 2024Polystyrene microplastics (PSMPs) have emerged as a ubiquitous environmental toxicant that affects different organs including testes. Ginkgetin (GNG) is a biflavonoid...
Pharmacotherapeutic potential of ginkgetin against polystyrene microplastics-instigated testicular toxicity in rats: A biochemical, spermatological, and histopathological assessment.
Polystyrene microplastics (PSMPs) have emerged as a ubiquitous environmental toxicant that affects different organs including testes. Ginkgetin (GNG) is a biflavonoid that shows antioxidant properties. The current research was undertaken to evaluate the ameliorative potential of GNG against PSMPs-instigated testicular damages. Forty-eight albino rats (male) were randomly divided into 4 equal groups: control, PSMPs-treated group (0.01 mgkg), GNG + PSMPs-exposed group (25 mgkg + 0.01 mgkg), and only GNG-supplemented group (25 mgkg). After 56 days of treatment, it was revealed that PSMPs significantly reduced the activity of glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GSR), while concurrently augmented the levels of lipid peroxidation marker, i.e., malondialdehyde (MDA) along with reactive oxygen species (ROS). Rats administered with PSMPs showed a significant reduction in the spermatogenic indices (sperm count, viability, and motility), HOS coiled tail sperm along with increased sperm structural deformities, i.e., tail, head, and mid-piece. Additionally, PSMPs exposure decreased the levels of testosterone, luteinizing (LH), and follicle-stimulating hormones (FSH). Besides, administration of PSMPs reduced the steroidogenic enzymes (13β-HSD, StAR, and 17β-HSD) and Bcl-2 expression, while augmented the caspase-3 and Bax expression. PSMPs also elevated the levels of inflammatory markers (IL-6, IL-1β, TNF-α, and NF-κB) and activity of COX-2 in the testes. Furthermore, PSMPs treatment induced various histopathological damages in the testes of rats. Therefore, findings of the current study suggested that GNG effectively mitigated the PSMPs-induced testicular toxicity owing to its chemoprotective potential possibly through its anti-inflammatory, antioxidant, anti-apoptotic, and androgenic properties.
Topics: Rats; Male; Animals; Testis; Antioxidants; Biflavonoids; Microplastics; Plastics; Polystyrenes; Oxidative Stress; Rats, Wistar; Semen; Testosterone
PubMed: 38182957
DOI: 10.1007/s11356-023-31662-7 -
Theriogenology Mar 2024Liquid storage of turkey semen without the loss of fertilizing ability is of practical interest to the poultry industry. However, fertility rates from liquid-stored...
Liquid storage of turkey semen without the loss of fertilizing ability is of practical interest to the poultry industry. However, fertility rates from liquid-stored turkey semen decline within a few hours. A clear cause of the decline in spermatozoa quality remains unidentified. Therefore, the purpose of the present study was to monitor the dynamics of proteomic changes in spermatozoa during 48 h of liquid storage by 2-dimensional difference in-gel electrophoresis coupled with matrix-assisted laser desorption/ionization mass spectrometry. A total of 57 protein spots were differentially expressed between fresh and stored spermatozoa; 42 spots were more and 15 were less abundant after 48 h of semen storage. Raw proteomic data are available via ProteomeXchange with identifier PXD043050. The selected differentially expressed proteins (DEPs) were validated by western blotting and localized in specific spermatozoa structures by immunofluorescence, such as the head (acrosin and tubulin α), midpiece (acrosin, aconitate hydratase 2, and glycerol-3-phosphate dehydrogenase) and tail (tubulin α). Most of the DEPs that changed in response to liquid storage were related to flagellum-dependent cell motility, energy derivation through oxidation of organic compounds and induction of fertilization, suggesting the complexity of the processes leading to the decrease in stored semen quality. The damaging effect of liquid storage on spermatozoa flagellum manifested as more microtubule proteins, such as tubulins and tektins, most likely formed by posttranslational modifications, tubulin α relocation from the tail to the sperm head, which appeared after 48 h of semen storage, and decreases in fibrous shelf proteins at the same time. Motility could be affected by dysregulation of Ca-binding proteins and disturbances in energy metabolism in spermatozoa flagellum. Regarding sperm mitochondria, DEPs involved in energy derivation through the oxidation of organic compounds indicated disturbances in fatty acid beta oxidation and the tricarboxylic acid cycle as possible reasons for energy deficiency during liquid storage. Disturbances in acrosin and 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase zeta may be involved in rapid declines in the fertility potential of stored turkey spermatozoa. These results showed the complexity of the processes leading to a decrease in stored semen quality and broadened knowledge of the detrimental effects of liquid storage on turkey spermatozoa physiology.
Topics: Male; Animals; Semen; Semen Analysis; Acrosin; Tubulin; Proteomics; Sperm Motility; Semen Preservation; Spermatozoa; Turkeys
PubMed: 38159387
DOI: 10.1016/j.theriogenology.2023.12.026 -
Biology of Reproduction Apr 2024The protein kinase A (PKA) signaling pathway, which mediates protein phosphorylation, is important for sperm motility and male fertility. This process relies on A-kinase...
The protein kinase A (PKA) signaling pathway, which mediates protein phosphorylation, is important for sperm motility and male fertility. This process relies on A-kinase anchoring proteins that organize PKA and its signalosomes within specific subcellular compartments. Previously, it was found that the absence of A-kinase anchoring protein 3 (AKAP3) leads to multiple morphological abnormalities in mouse sperm. But how AKAP3 regulates sperm motility is yet to be elucidated. AKAP3 has two amphipathic domains, here named dual and RI, in its N-terminus. These domains are responsible for binding regulatory subunits I alpha (RIα) and II alpha (RIIα) of PKA and for RIα only, respectively. Here, we generated mutant mice lacking the dual and RI domains of AKAP3. It was found that the deletion of these domains caused male mouse infertile, accompanied by mild defects in the fibrous sheath of sperm tails. Additionally, the levels of serine/threonine phosphorylation of PKA substrates and tyrosine phosphorylation decreased in the mutant sperm, which exhibited a defect in hyperactivation under capacitation conditions. The protein levels of PKA subunits remained unchanged. But, interestingly, the regulatory subunit RIα was mis-localized from principal piece to midpiece of sperm tail, whereas this was not observed for RIIα. Further protein-protein interaction assays revealed a preference for AKAP3 to bind RIα over RIIα. Collectively, our findings suggest that AKAP3 is important for sperm hyperactivity by regulating type-I PKA signaling pathway mediated protein phosphorylation via its dual and RI domains.
Topics: Animals; Male; Mice; A Kinase Anchor Proteins; Cyclic AMP-Dependent Protein Kinase Type I; Cyclic AMP-Dependent Protein Kinases; Fertility; Semen; Signal Transduction; Sperm Motility; Spermatozoa; Sperm Capacitation
PubMed: 38145487
DOI: 10.1093/biolre/ioad180 -
Biomedicines Dec 2023Nerve growth factor (NGF) signalling affects spermatogenesis and mature sperm traits. In this paper, we aimed to evaluate the distribution and the role of NGF and its...
Nerve growth factor (NGF) signalling affects spermatogenesis and mature sperm traits. In this paper, we aimed to evaluate the distribution and the role of NGF and its receptors (p75 and TrKA) on the reproductive apparatus (testis and epididymis) and sperm of fertile men (F) and men with different pathologies, namely varicocele (V) and urogenital infections (UGIs). We collected semen samples from 21 individuals (31-40 years old) subdivided as follows: V ( = 7), UGIs ( = 7), and F ( = 7). We submitted the semen samples to bacteriological analysis, leucocyte identification, and analysis of sperm parameters (concentration, motility, morphology, and viability). We determined the seminal plasma levels of NGF, interleukin 1β (IL-1β), and F-isoprostanes (F-IsoPs), and the gene and protein expression of NGF receptors on sperm. We also used immunofluorescence to examine NGF receptors on ejaculated sperm, testis, and epididymis. As expected, fertile men showed better sperm parameters as well as lower levels of NGF, FIsoPs, and IL-1β compared with men with infertility. Notably, in normal sperm, p75 and TrKA were localised throughout the entire tail. TrKA was also found in the post-acrosomal sheath. This localisation appeared different in patients with infertility: in particular, there was a strong p75 signal in the midpiece and the cytoplasmic residue or coiled tails of altered ejaculated sperm. In line with these findings, NGF receptors were intensely expressed in the epididymis and interstitial tissue of the testis. These data suggest the distinctive involvement of NGF and its receptors in the physiology of sperm from fertile men and men with infertility, indicating a possible role for new targeted treatment strategies.
PubMed: 38137566
DOI: 10.3390/biomedicines11123345 -
Impact of Z chromosome inversions on gene expression in testis and liver tissues in the zebra finch.Molecular Ecology Dec 2023Chromosomal inversions have been identified in many natural populations and can be responsible for novel traits and rapid adaptation. In zebra finch, a large region on...
Chromosomal inversions have been identified in many natural populations and can be responsible for novel traits and rapid adaptation. In zebra finch, a large region on the Z chromosome has been subject to multiple inversions, which have pleiotropic effects on multiple traits but especially on sperm phenotypes, such as midpiece and flagellum length. To understand the effect, the Z inversion has on these traits, we examined testis and liver transcriptomes of young males at different maturation times. We compared gene expression differences among three inversion karyotypes: AA, B*B* and AB*, where B* denotes the inverted regions on Z with respect to A. In testis, 794 differentially expressed genes were found and most of them were located on chromosome Z. They were functionally enriched for sperm-related traits. We also identified clusters of co-expressed genes that matched with the inversion-related sperm phenotypes. In liver, there were some enriched functions and some overrepresentation on chromosome Z with similar location as in testis. In both tissues, the overrepresented genes were located near the distal end of Z but also in the middle of the chromosome. For the heterokaryotype, we observed several genes with one allele being dominantly expressed, similar to expression patterns in one or the other homokaryotype. This was confirmed with SNPs for three genes, and interestingly one gene, DMGDH, had allele-specific expression originating mainly from one inversion haplotype in the testis, yet both inversion haplotypes were expressed equally in the liver. This karyotype-specific difference in tissue-specific expression suggests a pleiotropic effect of the inversion and thus suggests a mechanism for divergent phenotypic effects resulting from an inversion.
PubMed: 38126688
DOI: 10.1111/mec.17236 -
Cureus Nov 2023The purpose of this study is to examine whether 5-hydroxytryptamine (5-HT, also known as serotonin) regulates human sperm motility, focusing on 5-HT receptors....
The purpose of this study is to examine whether 5-hydroxytryptamine (5-HT, also known as serotonin) regulates human sperm motility, focusing on 5-HT receptors. Immunofluorescent staining revealed the existence of seven types of 5-HT receptors with a heterogeneous pattern of reactive sites. In detail, 5-HT, 5-HT, and 5-HT were detected in the post-acrosomal and mid-piece regions. The 5-HT and 5-HT receptors were mainly localized in the equatorial segment. 5-HT and 5-HT receptors were present in the neck and post-acrosomal regions. When examining the effects of 5-HT receptor antagonists on sperm motility, only the 5-HT receptor antagonist significantly reduced sperm motility. This suggests that the 5-HT receptor may have a regulatory function in sperm motility. Eventually, progressive motility should be attenuated to penetrate the oocyte for fertilization. The current study indicated heterogenous expression patterns and plausible functions of 5-HT receptors in human sperm.
PubMed: 38033435
DOI: 10.7759/cureus.49530 -
Veterinary Sciences Nov 2023This study aimed to investigate the relationship between the sperm quality and the osteopontin (OPN) concentration in the prostates of Malakli shepherd dogs. Ejaculates...
This study aimed to investigate the relationship between the sperm quality and the osteopontin (OPN) concentration in the prostates of Malakli shepherd dogs. Ejaculates were collected once by digital manipulation from 39 male dogs aged between 2 and 4 years and older. The first and third fractions of the ejaculate were centrifuged at 5000× for 30 min, and supernatants were stored at -80 °C for further analysis of OPN using a double-antibody sandwich method (SEA899CA, Cloude-Clone Corp, Houston, TX, USA). Meanwhile, the second fractions were evaluated for sperm motility, concentration, viability, and rate of abnormal spermatozoa (head, acrosome, midpiece and tail abnormalities). The average concentration of OPN was 8.7 ± 5.2 ng/mL, and it differed significantly between the 1st 10.4 ± 5.3 ng/mL and 3rd 7.4 ± 5 ng/mL fractions. According to ROC (receiver operating characteristic curve) analysis, the OPN concentration had a better diagnostic ability for sperm motility ( < 0.001) than for the rate of abnormal spermatozoa ( < 0.05). Additionally, the OPN concentration was negatively correlated with poor sperm morphology and motility. In conclusion, the OPN concentration in prostate-derived secretions may be a possible marker of sperm quality in dogs. Further research could explore the involvement of OPN in sperm motility during cryopreservation and in vivo fertility.
PubMed: 37999469
DOI: 10.3390/vetsci10110646 -
Toxicology and Applied Pharmacology Dec 2023Aflatoxin B (AFB) is the most hazardous aflatoxin that causes significant damage to the male reproductive system. Genkwanin (GNK) is a bioactive flavonoid that shows...
Aflatoxin B (AFB) is the most hazardous aflatoxin that causes significant damage to the male reproductive system. Genkwanin (GNK) is a bioactive flavonoid that shows antioxidant and anti-inflammatory potential. Therefore, the current study was planned to evaluate the effects of GNK against AFB-induced testicular toxicity. Forty-eight male rats were distributed into four groups (n = 12 rats). AFB (50 μg/kg) and GNK (20 mg/kg) were administered to the rats for eight weeks. Results of the current study revealed that AFB exposure induced adverse effects on the Nrf2/Keap1 pathway and reduced the expressions and activities of antioxidant enzymes. Additionally, it increased the levels of oxidative stress markers. Furthermore, expressions of steroidogenic enzymes were down-regulated by AFB intoxication. Besides, AFB exposure reduced the levels of gonadotropins and plasma testosterone, which subsequently reduced the epididymal sperm count, motility, and hypo-osmotic swelled (HOS) sperms, while increasing the number of dead sperms and causing morphological anomalies of the head, midpiece, and tail of the sperms. In addition, AFB decreased the activities of testicular function marker enzymes and the levels of inflammatory markers. Moreover, it severely affected the apoptotic profile by up-regulating the expressions of Bax and Casp3, while down-regulating the Bcl2 expression. Besides, AFB significantly damaged the histoarchitecture of testicular tissues. However, GNK treatment reversed all the AFB-induced damages in the rats. Taken together, the current study reports the potential use of GNK as a therapeutic agent to prevent AFB-induced testicular toxicity due to its antioxidant, anti-inflammatory, and anti-apoptotic properties.
Topics: Male; Rats; Animals; Antioxidants; Aflatoxin B1; Kelch-Like ECH-Associated Protein 1; NF-E2-Related Factor 2; Semen; Oxidative Stress; Anti-Inflammatory Agents
PubMed: 37980962
DOI: 10.1016/j.taap.2023.116750