Andrology最新文献

Background: Asthenozoospermia, characterized by reduced sperm motility, is a common cause of male infertility. Multiple morphological abnormalities of the sperm flagella (MMAF) represent a severe and genetically heterogeneous form of asthenozoospermia. Over 50 genes have been associated, but approximately half of MMAF cases remain unexplained. DRC1, a gene involved in the nexin-dynein regulatory complex (N-DRC), has been linked to MMAF and primary ciliary dyskinesia (PCD), often with significant variability in clinical presentation.

Objectives: His study aimed to identify novel pathogenic DRC1 variants in MMAF patients, assess their impact on sperm flagellar structure, and evaluate intracytoplasmic sperm injection (ICSI) and pregnancy outcomes.

Materials and methods: A cohort of 196 non-syndromic MMAF patients was analyzed using whole exome sequencing (WES). Functional validation of candidate variants included immunofluorescence to assess protein expression and transmission electron microscopy (TEM) to identify ultrastructural abnormalities. Assisted reproductive therapy outcomes were also evaluated.

Results: WES identified a recurrent homozygous frameshift variant in DRC1 NM_145038.5: c.109dup; p.(Gln37ProfsTer30) in four patients (2%), all of North African origin, none of whom suffer from PCD-related symptoms. The variant caused a complete absence of DRC1 protein in spermatozoa. TEM showed flagellar abnormalities, with 10% of axonemal sections revealing peripheral doublet dissociation, suggesting N-DRC instability. ICSI resulted in a 68.5% fertilization rate, with three out of four couples successfully delivering healthy children.

Discussion and conclusion: The identification of a novel and recurrent pathogenic DRC1 variant broadens the mutation spectrum associated with MMAF. The absence of systemic PCD symptoms suggests that DRC1 deficiency may primarily affect spermatogenesis. Notably, the phenotypic spectrum might be influenced by the genetic background, varying across populations. Favorable ICSI outcomes, with a 68.5% fertilization rate and successful pregnancies in three out of four couples, highlight the effectiveness of assisted reproductive techniques for patients with this genetic defect.

Across six decades, androgenetics has consistently concentrated on discovering genetic causes and enhancing the molecular diagnostics of male infertility, disorders of sex development, and their broader implications on health, such as cancer and other comorbidities. Despite vast clinical knowledge, the training of andrologists often lacks fundamental basics in medical genetics. This work, as part of the Special Issue of Andrology "Genetics in Andrology", provides the core terminology in medical genetics and technological advancements in genomics, required to understand the ever-progressing research in the field. It also gives an overview of study designs and approaches that have frequently led to discoveries in androgenetics. The rapid progress in the methodological toolbox in human genetics is illustrated by numerous examples of impactful androgenetic studies over 60 years, and their clinical implications.

Background: 6-Nitrodopamine (6-ND) released from rat vas deferens acts an endogenous modulator of vas deferens contractility.

Objectives: To investigate whether rat isolated seminal vesicles (RISV) releases 6-ND, the mechanisms involved in the release, and the modulatory role of 6-ND on tissue contractility.

Methods: Rat seminal vesicles were removed and placed in Krebs-Henseleit's solution at 37°C for 30 min, and an aliquot was used to analyze the concentrations of 6-ND, dopamine, noradrenaline, and adrenaline by liquid chromatography with tandem mass spectrometry (LC-MS/MS). The effect of mechanical removal of the epithelium and the effects of pre-incubation of RISV strips with N^ω-nitro-L-arginine methyl ester (L-NAME; in combination or not with L-arginine), tetrodotoxin (TTX), GKT137831, and hydrogen peroxide (H₂O₂) on 6-ND release were evaluated. For functional studies, RISV strips were mounted in an organ bath and tied to an isometric force transducer. The expressions of tyrosine hydroxylase and endothelial nitric oxide synthase (eNOS, type III NOS) were investigated by immunohistochemistry and/or fluorescence in situ hybridization (FISH).

Results: 6-ND was the major released catecholamine from RISV strips compared with noradrenaline, adrenaline, and dopamine. Epithelium removal significantly reduced the release of 6-ND, noradrenaline and dopamine. In RISV strips obtained from animals chronically treated with L-NAME, the 6-ND release significantly reduced. Pre-incubation with L-NAME reduced 6-ND release, which was partly restored by co-incubation with L-arginine. Pre-incubation with TTX had no effect on the release of any catecholamine, whereas GKT137831 and H₂O₂ significantly increased 6-ND release. All catecholamines produced concentration-dependent RISV contractions, but 6-ND was approximately 30× less potent than the others. 6-ND (0.1 nM) significantly potentiated noradrenaline-, adrenaline-, and dopamine-induced contractions, with such potentiations inhibited by TTX. Immunohistochemistry and FISH assays in RISV tissues identified tyrosine hydroxylase in epithelial cells and eNOS expression in both epithelial and endothelial cells.

Discussion and conclusion: This is the first demonstration that epithelial-derived 6-ND modulates rat seminal vesicle contractility.

Background: Endocannabinoids like anandamide (AEA), among other lipids, are recognized signaling molecules that participate in reproductive events.

Objectives: Our aims were to characterize orphan G protein-coupled receptor (GPR55) presence; investigate GPR55 activation by AEA and determine GPR55 role in the bovine sperm function.

Materials and methods: GPR55 presence was assessed by immunocytochemistry. Protein kinase A (pPKA) and PKC (pPKC) substrates, pERK1/2, G/F-actin were determined by Western blotting, activation of RAC-1 by pull-down assay, F-actin and acrosomal exocytosis by fluorescence microscopy, sperm motility by optic microscopy and computer-aided sperm analysis and fertilizing ability by in vitro fertilization (IVF).

Results: We detected GPR55 in spermatozoa at T0, after incubation in non-capacitating and capacitating (presence of AEA) conditions and upon release from oviductal epithelia. AEA induced an increase in pPKA and pPKC, while CID16020046 (CID), selective GPR55 antagonist, prevented this effect. Incubation with H89, PKA inhibitor, significantly decreased pPKC, while Gö6983, a PKC inhibitor, partially reduced pPKA. pPKA remained elevated at 15- and 45-min incubation, while pPKC decreased at 15 and increased at 45 min. CID prevented pPKC increase at 5 and 45 min and decreased pPKA at 45 min. RAC-1 and F-actin increase induced by AEA was prevented by CID. Variations in two progressive motility kinematic parameters were observed with AEA and/or CID. Sperm pretreatment with AEA increased the rate of cleaved embryos and CID prevented this effect.

Discussion: We demonstrated that GPR55 activation by AEA induces time-dependent signaling pathways involving pPKA and pPKC during bovine sperm capacitation. AEA regulates actin polymerization through GPR55 activation, suggesting the receptor participates in cytoskeleton remodeling, and yielded higher IVF rates. Also, sperm pre-incubation with molecules like AEA involved in capacitation could improve the embryo development.

Conclusion: We have demonstrated GPR55 presence in bovine spermatozoa. The regulation of PKA and PKC and of molecules associated with cytoskeletal dynamics, such as RAC-1 and actin, by GPR55 is closely related to sperm motility and acrosomal exocytosis.

Background and objectives: Epididymal transit renders key competence to mammalian spermatozoa for fertilizing eggs. Generally, the two paralogs of glycogen synthase kinase 3, GSK3α and GSK3β, functionally overlap except in testis and sperm. We showed that GSK3α is essential for epididymal sperm maturation and fertilization. Male infertility is the only phenotype of mice with a global or testis-specific knockout (KO) of Gsk3α. Their sperm maturation is impaired, and sperm cannot fertilize eggs in vitro and in vivo. This suggests that GSK3α is a "male fertility kinase" in mammals and that GSK3α-selective inhibitor is a potential male contraceptive.

Materials and methods: A set of eight heterozygous Gsk3α(±) male mice received daily intraperitoneal injections of BRD0705, an isoform-selective GSK3α inhibitor, at 20 mg/kg body weight for 1 week. Five vehicle-treated and BRD0705-treated mice were tested for in vivo fertility and the remaining mice were sacrificed; their caudal spermatozoa were examined for motility and biochemical properties.

Results: The treated mice did not sire any pups while the control group sired 46 pups with a normal gestation period of 19-23 days. Continued fertility testing up to 6 weeks post-treatment, showed that the treated mice regained fertility siring 56 pups, with 76 in the control group. Sperm motility was impaired, its abnormal morphology increased during epididymal transit, Adenosine triphosphate (ATP) levels were low, and tyrosine-phosphorylation of hexokinase was absent: these phenotypes imitated those observed in Gsk3α KO mice. Tyrosine²⁷⁹-phosphorylation of GSK3α was reduced in sperm from the treated mice showing that the GSK3α activity was inhibited. The altered sperm phenotypes returned to normal following recovery of fertility.

Conclusions: Complete infertility resulted after 1 week of BRD0705-treatment and fertility recovered after cessation of the treatment. Work is ongoing to determine the minimum dose and treatment time and the testing of new compounds with increased selectivity and inhibitory activity against GSK3α.

Background: Although some studies have revealed the close relationship between leptin and premature ejaculation in clinical practice, whether and how leptin participates in the regulation of ejaculatory behaviors are still unknown.

Objective: To explore the role of leptin on ejaculatory behaviors and its underlying mechanism.

Materials and methods: Copulation behavior tests were performed after acute and chronic leptin administration at peripheral and central levels. To compare changes in sympathetic nervous system activity, lumbar sympathetic nervous activity, serum noradrenaline levels, and the distribution of sympathetic fibers in vas deferens and seminal vesicles were analyzed. Construction of virus vector, immunohistochemistry, and optogenetics techniques were used to explore the neural circuit mechanism. The density of dendritic spines in parvocellular region of paraventricular nucleus was measured by Golgi staining.

Results: Acute administration of leptin had no effect on ejaculation behavior in male mice. However, both mount latency and ejaculation latency were significantly shortened, even if serum leptin decreased to normal level, after chronic administration of leptin at peripheral or central level. Additionally, sympathetic fibers in vas deferens and seminal vesicles obviously increased, in which arcuate nucleus‒paraventricular nucleus circuit and glutamatergic neurons in paraventricular nucleus played an important role. Dendritic spine density in parvocellular region increased after chronic leptin administration.

Discussion and conclusion: The role of leptin in regulating ejaculation behavior was chronic, not acute, in which leptin chronically modulated sympathetic neuroplasticity via arcuate nucleus‒paraventricular nucleus circuit and glutamatergic neurons in paraventricular nucleus and promoted ejaculatory behaviors. Increased dendritic spine density in parvocellular region of paraventricular nucleus may be involved as well.

Background: In mammals, sperm fertilization potential relies on efficient progression within the female genital tract to reach and fertilize the oocyte. This fundamental property is supported by the flagellum, an evolutionarily conserved organelle, which contains dynein motor proteins that provide the mechanical force for sperm propulsion and motility. Primary motility of the sperm cells is acquired during their transit through the epididymis and hyperactivated motility is acquired throughout the journey in the female genital tract by a process called capacitation. These activation processes rely on the micro-environment of the genital tracts. In particular, during capacitation, a panoply of ion transporters located at the surface of the sperm cells mediate complex ion exchanges, which induce an increase in plasma membrane fluidity, the alkalinization of the cytoplasm and protein phosphorylation cascades that are compulsory for sperm hyperactivation and fertilization potential. As a consequence, both structural and functional defects of the sperm flagellum can affect sperm motility, resulting in asthenozoospermia, which constitutes the most predominant pathological condition associated with human male infertility.

Objectives: Herein, we have performed a literature review to provide a comprehensive description of the recent advances in the genetics of human asthenozoospermia.

Results and discussion: We describe the currently knowledge on gene mutations that affect sperm morphology and motility, namely, asthenoteratozoospermia; we also specify the gene mutations that exclusively affect sperm function and activation, resulting in functional asthenozoospermia. We discuss the benefit of this knowledge for patient and couple management, in terms of genetic counselling and diagnosis of male infertility as a sole phenotype or in association with ciliary defects. Last, we discuss the current strategies that have been initiated for the development of potential therapeutical and contraceptive strategies targeting genes that are essential for sperm function and activation.

Background: Evidence indicates a wide range of andrological alterations in patients with the Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) infection and Coronavirus Disease 2019 (COVID-19).

Aim: To provide an update on the andrological effects of SARS-CoV-2 infection and COVID-19.

Methods: PubMed/MEDLINE and Institutional websites were searched for randomized clinical trials, non-systematic reviews, systematic reviews, and meta-analyses.

Results: Fifty-four records were included from 2020 to 2024. The most representative paper categories were non-systematic reviews (n = 26) and systematic reviews/meta-analyses (n = 27). One randomized, prospective, phase 2 trial was also included. Eight topics were identified and discussed as follows: short- and long-term seminal changes attributable to SARS-CoV-2 infection or COVID-19; andrological effects of anti-SARS-CoV-2 vaccines; the potential impact of SARS-CoV-2 infection and COVID-19 on male fertility; the relationship between serum testosterone levels and COVID-19 prognosis in men; fertility care during the pandemic; urinary/genital male system tract impairment in SARS-CoV-2 infection and COVID-19; the effect of SARS-CoV-2 infection and COVID-19 on circulating levels of sex steroid hormones; the impact of SARS-CoV-2 and COVID-19 on sexual function and activity.

Discussion: SARS-CoV-2 can affect the whole testicular function through direct and indirect mechanisms, with a positive relation between the severity of SARS-CoV-2 infection and the level of deterioration of testicular function. Testicular function recovers along with the recovery from the disease. In vitro fertilization techniques ensure similar results in patients with or without previous SARS-CoV-2 infection or COVID-19. Immunization with anti-SARS-CoV-2 vaccines prevents andrological complaints due to naturally occurring infection. Erectile dysfunction and sexual dysfunction are frequently diagnosed in COVID-19 patients due to several contributing factors, including hormonal imbalance and psychosocial complaints related to the pandemic.

Background: The establishment of kinetochore-microtubule attachment is essential for error-free chromosome alignment and segregation during cell division. Defects in chromosome alignment result in chromosome instability, birth defects, and infertility. Kinesin-7 CENP-E mediates kinetochore-microtubule capture, chromosome alignment, and spindle assembly checkpoint in somatic cells, however, mechanisms of CENP-E in germ cells remain poorly understood.

Objectives: This study aimed to explore the functions of CENP-E in the proliferation and self-renewal of spermatogonia.

Materials and methods: A CENP-E heterozygous knockout strain was established in C57BL/6J mice using the CRISPR/Cas9 and Cre/LoxP system. Hematoxylin-eosin staining was performed to study the histology. The inhibition of CENP-E in the GC-1 spg cells was performed using the specific inhibitor GSK923295. The expression and localization of spermatogonial marker proteins were determined by immunofluorescence using confocal microscopy in the control and CENP-E^+/- heterozygous mouse testes. The protein expression level was analyzed using Western blot. The cell-cycle and apoptosis assay were measured using flow cytometry. In addition, karyotype analysis was performed using hypotonic preparation and chromosome spreading.

Results: Here, we reveal that CENP-E haploinsufficiency results in chromosome misalignment, spindle disorganization, and metaphase arrest in spermatogonia, which leads to the loss of spermatogonia, chromosomal instability, and spermatogenic disorders. Notably, CENP-E ablation leads to the activation of spindle assembly checkpoint and aneuploidy, which impairs the proliferation and self-renewal of spermatogonia.

Discussion and conclusion: CENP-E depletion disrupts the recruitment of key checkpoint proteins, including BubR1, Bub1, KIF2C, and Aurora B, indicating a causal relationship between chromosome misalignment and spindle assembly checkpoint activation in spermatogonia. Our findings demonstrate that CENP-E regulates kinetochore-microtubule attachment, chromosome alignment, and spindle assembly checkpoint in spermatogonia.