Successful spermatogenesis requires marked DNA condensation, chromatin remodeling via the histone-to-protamine transition, and maintenance of specific DNA methylation (DNAm) patterns. DNA fragmentation index (DFI), a marker of sperm DNA damage, and high DNA stainability (HDS), a marker of incomplete protamination, have been linked to poor reproductive outcomes. However, their relationship with sperm DNAm patterns remains largely unknown. The objective of this study was to investigate sperm DNAm profiles that are associated with sperm chromatin structure, assessed by DFI and HDS. This nested cross-sectional study assessed sperm DNAm using the EPIC V1 Infinium Methylation Beadchip from 376 participants from the general population enrolled in the prospective preconception pregnancy cohort: Longitudinal Investigation of Fertility and the Environment (LIFE) Study. DFI and HDS were measured with the sperm chromatin structure assay (SCSA). Linear regression (CpGassoc) and generalized estimating equations (Aclust2.0) algorithms, adjusted for male age and methylation at DLK1 and corrected for genomic inflation, were used to identify differentially methylated CpGs (DMCs) and regions (DMRs), respectively. Enrichment analysis of DMCs and DMRs across genic features, transcription factor (TF) binding motifs, and regions of histone retention was performed, as well as functional enrichment to elucidate biological relevance. DFI was not associated with sperm DNAm. HDS was associated with 18,187 DMCs and 1,241 DMRs (q<0.05), which were predominantly hypermethylated. Functional enrichment analysis revealed HDS-associated DNAm at genes involved in male reproduction and development-related pathways, such as male gamete generation, DNAm in gamete generation, male meiotic nuclear division, and epithelial tube morphogenesis. DMCs and DMRs were enriched in 39 TF binding sites (q<0.05), including those for master regulators of the cell cycle and pluripotency. HDS-associated DMCs and DMRs were also enriched in regions with retained testis-specific histone-variant-TH2B (absolute fold change >2; p<0.05). This is the first study, to our knowledge, to report associations between HDS and sperm DNAm profiles enriched in genomic regions important for spermatogenesis and male reproduction, as well as regions with retained TH2B. Despite the cross-sectional nature of the study, these findings suggest potential epigenetic communication between DNAm and chromatin remodeling during spermatogenesis, which may also involve intermediate histone proteins such as TH2B.
The development of targeted therapies is an unmet clinical need for testicular cancer, especially for those patients that do not respond to platinum-based therapy. While testicular germ cell tumors (TGCTs) are generally curable, a significant number of patients develop refractory metastatic disease, underscoring an urgent need for the discovery of novel therapeutic targets. Epigenetic dysregulation and activation of LINE1 retrotransposons are frequent in seminoma due to genome hypomethylation. Beyond retrotransposition, LINE1 elements can regulate gene expression through bidirectional promoter activity and generate antisense transcripts. As LINE1 activity is tightly controlled by PIWI-interacting RNAs (piRNAs), we investigated whether disruption of this pathway may contribute to TGCTs tumorigenesis by impacting on the expression of LINE1-derived lncRNAs with oncogenic activity. Through integrated analyses, we identified a novel oncogenic axis involving transposable element (TE)-derived lncRNAs associated with dysregulated piRNA expression. A TGCT-specific piRNA signature was identified and mapping of piRNAs to LINE1 sequences identified piR-hsa-7221 as a transcriptional regulator of the lncRNA CASC9 in seminoma. The effect of piR-hsa-7221 was mediated by binding to a complementary LIPA5 sequence and regulating the expression of CASC9 driven by the LINE1 antisense promoter. Loss of piR-hsa-7221 resulted in CASC9 upregulation and oncogenic activity, which was reduced by CASC9 silencing, leading to decreased cancer cell proliferation and invasion, as well as increased sensitivity to cisplatin treatment. Transcriptomic analysis linked these effects to the regulation of the cell cycle, developmental pathways, extracellular matrix, hormone metabolism and immune responses, with WNT signalling emerging as a key downstream target. This study describes a novel epigenetic mechanism in TGCTs involving piRNA-mediated regulation of LINE1-derived oncogenic lncRNAs. This mechanism provides new insights into seminoma pathogenesis and identifies the piR-hsa-7221 and CASC9 axis, together with associated gene networks as potential biomarkers and therapeutic targets.
Kagami-Ogata syndrome (KOS14) is a rare 14q32-related imprinting disorder. Since existing clinical data have mostly been limited to infancy and early childhood, long-term growth, maturation patterns, and neurodevelopmental outcomes remain poorly understood. In this study, we aimed to characterize the comprehensive clinical spectrum of KOS14. We obtained detailed clinical findings in 67 Japanese patients with molecularly confirmed KOS14 (37 with paternal uniparental disomy for chromosome 14 [UPD(14)pat], 17 with epimutation, 12 with deletions, and one with UPD(14)pat or epimutation). Polyhydramnios, placentomegaly, characteristic facial features with depressed nasal bridge, full cheeks, and protruding philtrum, and bell-shaped small thorax with coat-hanger appearance of the ribs were identified in nearly all patients. The characteristic face and coat-hanger appearance of the ribs remained diagnostic from infancy through adulthood. Respiratory distress was present in all patients at birth. The median duration of respiratory support was approximately 6 months, although support persisted beyond school age in around 5
Obesity is associated with various age-related diseases, including diabetes, atherosclerosis, and cancer, and it has been proposed that obesity accelerates biological aging. Epigenetic age acceleration (EAA), derived from DNA methylation-based epigenetic clocks, is a biomarker of biological aging, lifespan, and disease. We assessed whether metabolic and atherosclerotic complications are associated with EAA in individuals with overweight or obesity, and we explored potential inflammatory and metabolic underlying pathways. Cross-sectional observational cohort study in 299 individuals (median age 67.0 years) with a BMI > 27 kg/m2. We assessed vascular stiffness with pulse wave velocity (PWV), and carotid atherosclerosis by ultrasound. We calculated associations between EAA and MetS, vascular stiffness, and atherosclerosis. We explored underlying mechanisms by measuring circulating cytokines and adipokines, immune cell profiles, and adipose tissue (AT) inflammation. MetS presence was strongly associated with EAA according to the GrimAge and GrimAge2 clocks. EAA was also associated with circulating cytokine concentrations, and circulating monocytes, but not with AT inflammation. The association between MetS and EAA was partly mediated by reduced circulating adiponectin and increased monocyte counts. EAA was associated with increased PWV, intima media thickness, and carotid atherosclerosis, but for these latter two associations significance disappeared after adjustment of classical cardiovascular risk factors. Findings were replicated in an independent cohort of 563 people living with HIV with a BMI > 27 kg/m2. These findings suggest that metabolic complications of obesity and systemic inflammation are associated with EAA, highlighting metabolic dysfunction as a potential contributor to premature biological aging in obesity, and EAA as a biomarker for metabolic and vascular complications in individuals with obesity.
Cholangiocarcinoma (CCA) is a malignant tumor originating from the biliary epithelium, with global incidence and mortality rates on the rise. Due to difficulties in early diagnosis and the fact that most patients are diagnosed at an advanced stage, the prognosis for CCA is extremely poor. Currently, gemcitabine combined with cisplatin serves as the first-line regimen for advanced CCA, but its clinical efficacy is significantly limited by drug resistance. Therefore, there is an urgent need to identify new therapeutic targets. Epigenetic abnormalities are a critical feature in the development and progression of CCA, among which the imbalance of histone acetylation and deacetylation is particularly crucial. Histone Deacetylase 1 (HDAC1), as a core member of class I HDAC family, is frequently overexpressed in CCA and closely associated with adverse patient outcomes. Various HDAC inhibitors have shown effectiveness in inhibiting tumor cell growth and inducing cell death, and the combination therapy of HDAC inhibitors with other anticancer drugs has demonstrated broad prospects. Thus, HDAC1 represents a promising epigenetic target in CCA treatment. In-depth analysis of the specific molecular mechanisms of HDAC1 in cholangiocarcinoma, development of highly selective HDAC1 inhibitors and exploration of optimized combination strategies of HDAC1 inhibitors with chemotherapy, immunotherapy and other targeted therapies can provide more precise and effective treatment options for CCA patients, thereby improving their prognosis.
