Asian journal of andrology最新文献

Abstract: Infertility is a global concern, and oligoasthenoteratozoospermia (OAT) is the most severe form of male infertility, characterized by reduced sperm count, decreased motility, and increased abnormal morphology. Multiple morphological abnormalities of the sperm flagella (MMAF) characterize the most severe type of OAT and are usually caused by loss-of-function mutations in the genes essential for vital aspects of sperm biology, including concentration, motility, and morphology. The fibrous sheath interacting protein 2 (FSIP2) plays an essential role in sperm flagellar structure and function by regulating such processes as intraflagellar transport and acrosome formation. The present study, employing whole-exome sequencing (WES), identified two FSIP2 mutations in one patient (patient 1), a homozygous missense (c.262C>A, p.P88T) and a homozygous frameshift mutation (c.10948_10951del, p.N3653Nfs*22), as well as a homozygous FSIP2 frameshift mutation (c.15982_15982del, p.I5328Lfs*33) in another patient (patient 2). The results of bioinformatics analysis indicate that the identified missense mutation (c.262C>A) is rare and predicted to have a deleterious effect on FSIP2. Transmission electron microscopy analysis of sperm revealed several abnormalities, including a disorganized mitochondrial sheath, absence of the central pair and some doublets of microtubules, and significant dysplasia of the fibrous sheath. Reverse transcription-polymerase chain reaction (RT-PCR) indicated significantly reduced FSIP2 messenger RNA (mRNA) levels in sperm lysate of the affected individuals. Immunofluorescence staining revealed a complete absence of FSIP2, A-kinase anchor protein 4 (AKAP4), sperm-associated antigen 6 (SPAG6), intraflagellar transport 20 (IFT20) and actin-like 7A (ACTL7A) proteins in the spermatozoa of patients. Thus, the novel FSIP2 variants identified in patient 1 and patient 2 are recognized as pathogenic mutations responsible for MMAF, providing valuable insights for genetic counseling and reproductive decision-making in affected males.

In the evaluation of male infertility, precise assessment of sperm functional competence has surpassed the requirements of conventional semen parameters. Existing computer-aided analysis systems are deficient at the molecular diagnostic level and also face challenges in live-cell fluorescence quantification. To address these issues, we have developed a novel integrated computational-imaging platform that combines a fine-tuned You Only Look Once version 8 (YOLOv8) architecture, tailored for the EVISEN dataset, with dual-probe fluorescence microscopy image segmentation, enabling simultaneous quantification of intracellular pH (pHi) and mitochondrial DNA G-quadruplexes (mtDNA G4s). By automating the localization of fluorescent foci, our algorithm systematically discriminates between the fluorescent signatures of the sperm head and principal piece, revealing correlations between fluorescence intensity ratios and sperm functional outcomes. This study demonstrates the potential of artificial intelligence (AI)-enhanced multimodal sperm analysis for molecular phenotyping of sperm functional competence. Integrating deep learning with live-cell fluorescence imaging, our platform offers a transformative tool for mechanistically informed diagnostics of male infertility.

Abstract: Recent studies have shown that shorter periods of ejaculatory abstinence may enhance certain sperm parameters, but the molecular mechanisms underlying these improvements are still unclear. This study explored whether reduced abstinence periods could improve semen quality, particularly for use in assisted reproductive technologies (ART). We analyzed semen samples from men with normal sperm counts ( n = 101) and those with low sperm motility or concentration ( n = 53) after 3-7 days of abstinence and then after 1-3 h of abstinence, obtained from the Reproductive & Genetic Hospital of CITIC-Xiangya (Changsha, China). Physiological and biochemical sperm parameters were evaluated, and the dynamics of transfer RNA (tRNA)-derived fragments (tRFs) were analyzed using deep RNA sequencing in five consecutive samples from men with normal sperm counts. Our results revealed significant improvement in sperm motility and a decrease in the DNA fragmentation index after the 1- to 3-h abstinence period. Additionally, we identified 245 differentially expressed tRFs, and the mitogen-activated protein kinase (MAPK) signaling pathway was the most enriched. Further investigations showed significant changes in tRF-Lys-TTT and its target gene mitogen-activated protein kinase kinase 2 ( MAP2K2 ), which indicates a role of tRFs in improving sperm function. These findings provide new insights into how shorter abstinence periods influence sperm quality and suggest that tRFs may serve as biomarkers for male fertility. This research highlights the potential for optimizing ART protocols and improving reproductive outcomes through molecular approaches that target sperm function.

Abstract: We aimed to assess the occlusive effectiveness of open-ended vasectomy with mucosal cautery and fascial interposition and to determine the factors associated with occlusion failure. We studied all vasectomies performed between September 1, 2020, and August 31, 2021, by four vasectomy surgeons from Quebec City, Quebec, Canada. Sociodemographic and clinical characteristics were extracted from the electronic medical records. Occlusive effectiveness was assessed in all men with at least one postvasectomy semen analysis (PVSA). The effectiveness criteria were adapted from those of the American Urological Association (AUA) vasectomy guideline. Among the 4000 eligible vasectomies, 2242 (56.1%) were followed by at least one PVSA, with 99 (4.4%) requiring more than one PVSA. Occlusive effectiveness was achieved in 2233 vasectomies (99.6%; 95% confidence interval [CI]: 99.3%-99.8%), with 2199 (98.1%) and 34 (1.5%) classified as confirmed and probable success, respectively. The final status of the three vasectomies (0.1%) was indeterminate. Occlusive failure was observed in six vasectomies (0.3%; 95% CI: 0.1%-0.6%). The four surgeons had a similar risk of failure. The only significant factor associated with failure was the difficulty in performing the vas occlusion reported by the surgeon (7.4% [2/27] vs 0.2% [4/2212]; relative risk = 41.0; 95% CI: 7.8-214.2). The high occlusive effectiveness observed in our study validates AUA recommendations, supporting the use of this technique. Difficulty in occlusion of the vas deferens, as reported by surgeons, was the only factor associated with vasectomy failure. This finding highlights the need for PVSA in such cases.

Abstract: Reactive oxygen species (ROS) play a dual role in mammalian spermatozoa. At high levels, they are detrimental to sperm function since they can promote oxidative stress that produces oxidation of protein, lipids, and sperm DNA. This oxidative damage is associated with male infertility. On the other hand, when ROS are produced at low levels, they participate in the redox signaling necessary for sperm capacitation. Capacitation-associated ROS are produced by the sperm oxidase, whose identity is still elusive, located in the plasma membrane of the spermatozoon. ROS, such as superoxide anion, hydrogen peroxide, nitric oxide, and peroxynitrite, activate protein kinases and inactivate protein phosphatases with the net increase of specific phosphorylation events. Peroxiredoxins (PRDXs), antioxidant enzymes that fight against oxidative stress, regulate redox signaling during capacitation. Among them, PRDX6, which possesses peroxidase and calcium-independent phospholipase A 2 (iPLA 2 ) activities, is the primary regulator of redox signaling and the antioxidant response in human spermatozoa. The lysophosphatidic acid signaling is essential to maintain sperm viability by activating the phosphatidylinositol 3-kinase/protein kinase (PI3K/AKT) pathway, and it is regulated by PRDX6 iPLA 2 , protein kinase C (PKC), and receptor-type protein tyrosine kinase. The understanding of redox signaling is crucial to pave the way for novel diagnostic tools and treatments of male infertility.

Abstract: The circadian clock is an important internal time regulatory system for a range of physiological and behavioral rhythms within living organisms. Testosterone, as one of the most critical sex hormones, is essential for the development of the reproductive system, maintenance of reproductive function, and the overall health of males. The secretion of testosterone in mammals is characterized by distinct circadian rhythms and is closely associated with the regulation of circadian clock genes. Here we review the central and peripheral regulatory mechanisms underlying the influence of circadian clock genes upon testosterone synthesis. We also examined the specific effects of these genes on the occurrence, development, and treatment of common male diseases, including late-onset hypogonadism, erectile dysfunction, male infertility, and prostate cancer.

Abstract: Lymphomas represent one of the most common malignant diseases in young men and an important issue is how treatments will affect their reproductive health. It has been hypothesized that chemotherapies, similarly to environmental chemicals, may alter the spermatogenic epigenome. Here, we report the genomic and epigenomic profiling of the sperm DNA from a 31-year-old Hodgkin lymphoma patient who faced recurrent spontaneous miscarriages in his couple 11-26 months after receiving chemotherapy with adriamycin, bleomycin, vinblastine, and dacarbazine (ABVD). In order to capture the potential deleterious impact of the ABVD treatment on mutational and methylation changes, we compared sperm DNA before and 26 months after chemotherapy with whole-genome sequencing (WGS) and reduced representation bisulfite sequencing (RRBS). The WGS analysis identified 403 variants following ABVD treatment, including 28 linked to genes crucial for embryogenesis. However, none were found in coding regions, indicating no impact of chemotherapy on protein function. The RRBS analysis identified 99 high-quality differentially methylated regions (hqDMRs) for which methylation status changed upon chemotherapy. Those hqDRMs were associated with 87 differentially methylated genes, among which 14 are known to be important or expressed during embryo development. While no variants were detected in coding regions, promoter regions of several genes potentially important for embryo development contained variants or displayed an altered methylated status. These might in turn modify the corresponding gene expression and thus affect their function during key stages of embryogenesis, leading to potential developmental disorders or miscarriages.

Abstract: This study explores whether the current external quality assessment (EQA) level and acceptable bias for basic semen analysis in China are clinically useful. We collected data of semen EQA from Andrology laboratories in the Hunan Province (China) in 2022 and searched for data in the published literature from January 2000 to December 2023 in China. On the basis of these data, we analyzed the coefficients of variation and acceptable biases of different quality control materials for basic semen analysis through robust statistics. We compared these findings with quality specifications based on biological variation from optimal, desirable, and minimum levels of bias to seek a unified and more suitable semen EQA bias evaluation standard for China's national conditions. Different sources of semen quality control material exhibited considerable variation in acceptable biases among laboratories, ranging from 8.2% to 56.9%. A total of 50.0% of the laboratories met the minimum quality specifications for progressive motility (PR), whereas 100.0% and 75.0% of laboratories met only the minimum quality specifications for sperm concentration and total motility (nonprogressive [NP] + PR), respectively. The Z value for sperm concentration and PR+NP was equivalent to the desirable performance specification, whereas the Z value for PR was equivalent only to the minimum performance specification. This study highlights the feasibility of operating external quality assessment schemes for basic semen analysis using quality specifications based on biological variation. These specifications should be unified among external quality control (EQC) centers based on biological variation.

Abstract: In contrast to the conventional spermiogram, metabolomics approaches give insights into the molecular composition of semen and may provide more detailed information on the fertility status of the respective donor. Given the intra-individual variability of spermiogram parameters between two donations, this study sought to elucidate the biological variability of the seminal plasma metabolome over an average period of 8 weeks. Two time-shifted semen samples from 15 healthy donors were compared by a targeted metabolomics approach utilizing the Biocrates AbsoluteIDQ p180 kit. Next to intraclass correlation coefficients (ICC), which represent a measure of reliability, coefficients of variation within individuals (CVW) and coefficients of variation between individuals (CVB) were calculated for each metabolite to demonstrate its stability. Furthermore, men were divided into two cohorts, a similar sperm concentration (SSC) and a differing sperm concentration (DSC) cohort, based on the observed variance in sperm concentration between the two semen donations. The ICC was higher in the SSC compared to the DSC cohort. The levels of 18 metabolites, primarily acylcarnitines, varied between the initial and subsequent donations. After subdivision into subgroups, only ornithine and phosphatidylcholine 40:5 exhibited differential levels between the two donations in the SSC group, compared to 14 metabolites in the DSC group. CVB was higher than CVW but both differed between the metabolite subclasses. Biogenic amines were identified as the least reliable analytes over time, exhibiting the highest CVW, compared to sphingomyelins, which demonstrated the highest reliability with the lowest variation. CVB was the highest for ether-bound glycerophosphatidylcholines and the lowest for amino acids.