Nonobstructive azoospermia (NOA) is a severe and heterogeneous form of male factor infertility caused by dysfunction of spermatogenesis. Although various factors are well defined in the disruption of spermatogenesis, not all aspects due to the heterogeneity of the disorder have been determined yet. In this review, we focus on the recent findings and summarize the current data on epigenetic mechanisms such as DNA methylation and different metabolites produced during methylation and demethylation and various types of small noncoding RNAs involved in the pathogenesis of different groups of NOA.
Humans ; Azoospermia/metabolism* ; Male ; DNA Methylation/genetics* ; Epigenesis, Genetic ; Spermatogenesis/genetics* ; RNA, Small Untranslated/genetics*

Spermatogenesis is a fundamental process that requires a tightly controlled epigenetic event in spermatogonial stem cells (SSCs). The mechanisms underlying the transition from SSCs to sperm are largely unknown. Most studies utilize gene knockout mice to explain the mechanisms. However, the production of genetically engineered mice is costly and time-consuming. In this study, we presented a convenient research strategy using an RNA interference (RNAi) and testicular transplantation approach. Histone H3 lysine 9 (H3K9) methylation was dynamically regulated during spermatogenesis. As Jumonji domain-containing protein 1A (JMJD1A) and Jumonji domain-containing protein 2C (JMJD2C) demethylases catalyze histone H3 lysine 9 dimethylation (H3K9me2), we firstly analyzed the expression profile of the two demethylases and then investigated their function. Using the convenient research strategy, we showed that normal spermatogenesis is disrupted due to the downregulated expression of both demethylases. These results suggest that this strategy might be a simple and alternative approach for analyzing spermatogenesis relative to the gene knockout mice strategy.
Spermatogenesis/physiology* ; Animals ; Male ; Mice ; Epigenesis, Genetic ; Jumonji Domain-Containing Histone Demethylases/metabolism* ; Histones/metabolism* ; RNA Interference ; Testis/metabolism* ; Methylation ; Mice, Knockout ; Histone Demethylases

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.
Humans ; Male ; Hodgkin Disease/drug therapy* ; Adult ; DNA Methylation/drug effects* ; Bleomycin/therapeutic use* ; Spermatozoa/metabolism* ; Vinblastine/therapeutic use* ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; Abortion, Habitual/genetics* ; Doxorubicin/therapeutic use* ; Dacarbazine/therapeutic use* ; Female ; Pregnancy

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by social impairments, repetitive behaviors, and restricted interests. Studies have shown that it is more prevalent in males than females. Although this issue has attracted academic attention since the 20th century, the specific mechanisms underlying the gender differences in ASD remain unclear. This paper reviews the impact of gender differences in ASD, focusing on the female protective effect, DNA methylation, hormone levels, and clinical manifestations. It also discusses corresponding treatment options, particularly suggesting improvements in the diagnostic process, which is often overlooked, in order to provide valuable references for the clinical diagnosis and treatment of ASD.
Humans ; Autism Spectrum Disorder/genetics* ; Female ; Male ; DNA Methylation ; Sex Factors ; Sex Characteristics

OBJECTIVE: To investigate the whole-genome differential methylation profile of patients with high-altitude polycythemia (HAPC). METHODS: In this study, a total of 20 adult male patients with HAPC were included, including 10 Tibetan and 10 Han patients. The control group consisted of 20 healthy adult males, including 10 Tibetan and 10 Han patients. Peripheral blood was collected from each group for DNA extraction and quality inspection, and DNA libraries were constructed. The differential methylation regions (DMRs) between groups were detected using reduced representation bisulfite sequencing, with enriched regions compared to those of the control group. The differential enrichment regions were selected, and the intersection of the enriched regions was associated with genes. The methylation enrichment regions that differed significantly between groups were filtered based on the number of enriched samples in the enriched regions between the groups. GO, KEGG functional, and pathway analysis were performed on the differentially associated gene sets to reveal significant differences between the patients and control groups at the functional and pathway levels. RESULTS: In comparison with the control group, 17 152 sites with more than 25% difference and 15 558 sites with less than -25% difference were identified in Tibetan patients. The top 5 genes with the largest methylation differences between the two groups were MCCC2, RP3-399L15.3, ZNF621, RP11-394A14.2 and SLC39A10. The top significantly different pathways annotated in the differentially expressed genes pathway was serotonergic synapse. In comparison with the control group, 2 687 CpG sites with a greater than 25% difference and 2 602 CpG sites with a less than -25% difference were identified in Han patients. The top 5 genes with the largest methylation differences between the two groups were NAA25, CORO2B, PDC, ZNF853, and MLLT10. The top significantly different pathways annotated in the differentially expressed genes pathway were glutamatergic synapse, retrograde endocannabinoid signaling, Rap1 signaling pathway and cholinergic synapse. In comparison with the control group, 3 895 CpG sites with a greater than 25% difference and 3 969 CpG sites with a less than -25% difference were identified in HAPC patients. The maximum methylation difference between the two groups could reach 78.1%, while the minimum was -42.6%. The top 5 genes with the largest methylation differences between the two groups were MCCC2, ARSJ, CTNNA3, SLC39A10, and SWAP70. The top significantly different pathways annotated in the differentially expressed genes pathway was signaling pathways regulating pluripotency of stem cells. CONCLUSION The occurrence of HAPC may be related to abnormal changes in DNA methylation, and methylation sites may be helpful for the early diagnosis of HAPC.
Humans ; DNA Methylation ; Altitude ; Polycythemia/genetics* ; Male ; Adult ; CpG Islands

OBJECTIVE: To study the efficacy and prognosis of patients with myelodysplastic/myeloproliferative neoplasms (MDS/MPN) treated with hypomethylating agents (HMA), and to analyze the factors that may affect their efficacy and prognosis, in order to provide a clinical basis for the choice of treatment options for patients with MDS/MPN. METHODS: 35 patients with newly diagnosed MDS/MPN who received hypomethylating therapy from January 2018 to April 2024 in the Department of Hematology of Affiliated Hospital of Xuzhou Medical University were included. The patients were divided into decitabine group (15 cases) and azacitidine group (20 cases) according to the treatment regimen. The efficacy, median overall survival (OS), and median progression-free survival (PFS) of the patients after HMA treatment were evaluated. The differences in efficacy and survival between the two groups were compared, and factors affecting efficacy and prognosis of MDS/MPN patients were analyzed. RESULTS: The overall response rate (ORR) of the 35 MDS/MPN patients treated with HMA was 51.4%. The ORR was 73.3% in decitabine group and 35.0% in azacitidine group, with a statistically significant difference (P =0.041). Survival analysis showed that the median OS was 12 months and the median PFS was 10 months in the entire cohort of the patients. There was no difference in median OS between decitabine group and azacitidine group. The median PFS in decitabine group was 12 months, higher than that in azacitidine group (7 months), but the difference was not statistically significant (P =0.505). Multivariate analysis showed that the treatment regimen and platelet count were independent influencing factors for the efficacy of HAM treatment; The course and therapeutic efficacy of HMA treatment were independent influencing factors for OS in MDS/MPN patients. The main adverse reactions of HMA treatment were myelosuppression and pulmonary infection. Gastrointestinal reactions were more likely to occur in the azacitidine group than in the decitabine group, and the difference was statistically significant (P =0.027). CONCLUSION HMA treatment is effective and well-tolerated in some MDS/MPN patients. Decitabine shows superior efficacy compared with azacitidine and is less likely to cause gastrointestinal reactions. Patients who received ≥4 courses of HMAs and responded to hypomethylating therapy had longer OS.
Humans ; Prognosis ; Decitabine/therapeutic use* ; Azacitidine/therapeutic use* ; Male ; Female ; Myelodysplastic Syndromes/drug therapy* ; Middle Aged ; Myelodysplastic-Myeloproliferative Diseases/drug therapy* ; Antimetabolites, Antineoplastic/therapeutic use* ; Treatment Outcome ; Aged ; Myeloproliferative Disorders/drug therapy* ; Adult ; DNA Methylation

In recent years, with the development of single-cell sequencing technology, spatial transcriptome technology and in vivo tracing technology, scientists have a deeper understanding of scientific issues about the in vivo development, functional regulation and ex vivo expansion of hematopoietic stem cells (HSCs). Among them, epigenetic modification plays an important role in the development and fate decisions, function maintenance and ex vivo expansion of HSCs, which has become a research hotspot in the field of stem cells in recent years. This article reviews the recent research progress of epigenetic modification in the development, functional regulation and expansion of HSCs.
Hematopoietic Stem Cells ; Epigenesis, Genetic ; Humans ; DNA Methylation

Male factors contribute to infertility at roughly the same rate as female factors, and sperm DNA methylation in advanced-aged males directly affects semen parameters and significantly reduces fertility and increases the miscarriage rate of spouses. Many adverse outcomes of reproductive health are associated with advanced reproductive age of men, and few studies are reported on the influence of paternal age on the health of the offspring. The role of advanced age in human sperm DNA methylation variation and mechanism of its subsequent influence on the offspring health remain unclear. Attention should be paid to the influence of reproductive age on pregnancy outcomes in this population. This reviews focuses on the impacts of advanced male age on sperm DNA methylation and consequently on reproductive outcomes and the offspring, with elucidation of its underlying mechanisms, aiming to provide some more useful evidence for solving related clinical problems.
Humans ; DNA Methylation ; Male ; Spermatozoa/metabolism* ; Female ; Pregnancy ; Paternal Age ; Pregnancy Outcome ; Embryonic Development

BACKGROUND: Prolonged occupational noise exposure poses potential health risks, but its impact on mitochondrial DNA (mtDNA) damage and methylation patterns remains unclear. METHOD: We recruited 306 factory workers, using average binaural high-frequency hearing thresholds from pure-tone audiometry to assess noise exposure. MtDNA damage was evaluated through mitochondrial DNA copy number (mtDNAcn) and lesion rate, and mtDNA methylation changes were identified via pyrophosphate sequencing. RESULTS: There was a reduction in MT-RNR1 methylation of 4.52% (95% CI: -7.43% to -1.62%) among workers with abnormal hearing, whereas changes in the D-loop region were not statistically significant (β = -2.06%, 95% CI: -4.44% to 0.31%). MtDNAcn showed a negative association with MT-RNR1 methylation (β = -0.95, 95% CI: -1.23 to -0.66), while no significant link was found with D-loop methylation (β = -0.05, 95% CI: -0.58 to 0.48). Mediation analysis indicated a significant increase in mtDNAcn by 10.75 units (95% CI: 3.00 to 21.26) in those with abnormal hearing, with MT-RNR1 methylation mediating 35.9% of this effect. CONCLUSIONS These findings suggest that occupational noise exposure may influence compensatory increases in mtDNA content through altered MT-RNR1 methylation.
Humans ; DNA, Mitochondrial ; DNA Methylation ; Male ; Adult ; Noise, Occupational/adverse effects* ; Middle Aged ; Occupational Exposure/adverse effects* ; Biomarkers/blood* ; Female

Neuropsychiatric disorders arise from complex interactions between genetic and environmental factors. DNA methylation, a reversible and environmentally responsive epigenetic regulatory mechanism, serves as a crucial bridge linking environmental exposure, gene expression regulation, and neurobehavioral outcomes. During long-duration deep-space missions, astronauts face multiple stressors-including microgravity, cosmic radiation, circadian rhythm disruption, and social isolation, which can induce alterations in DNA methylation and increase the risk of neuropsychiatric disorders. Genome-wide DNA methylation research can be divided into 3 major methodological stages: Study design, sample preparation and detection, and data analysis, each of which can be applied to astronaut neuropsychiatric health monitoring. Systematic comparison of the Illumina MethylationEPIC array and whole-genome bisulfite sequencing reveals their complementary strengths in terms of genomic coverage, resolution, cost, and application scenarios: the array method is cost-effective and suitable for large-scale population studies and longitudinal monitoring, whereas sequencing provides higher resolution and coverage and is more suitable for constructing detailed methylation maps and characterizing individual variation. Furthermore, emerging technologies such as single-cell methylation sequencing, nanopore long-read sequencing, and machine-learning-based multi-omics integration are expected to greatly enhance the precision and interpretability of epigenetic studies. These methodological advances provide key support for establishing DNA-methylation-based monitoring systems for neuropsychiatric risk in astronauts and lay an epigenetic foundation for safeguarding neuropsychiatric health during future long-term deep-space missions.
DNA Methylation ; Humans ; Space Flight ; Mental Disorders/genetics* ; Epigenesis, Genetic ; Astronauts/psychology* ; Weightlessness/adverse effects* ; Epigenomics