Search Results (858)

Background/Objectives: Synthetic stimulants represent the most prevalent subclass on the new psychoactive substances (NPSs) market. However, the toxicokinetic properties of M-ALPHA, a regioisomer of MDMA and N-methyl-cyclazodone a pemoline derivative, are not yet characterized. Methods: Therefore, this study investigated the metabolism of both NPSs in pooled liver S9 fraction and rat urine, characterized cytochrome P450 (CYP) kinetics and plasma protein binding (PPB), and assessed the CYP inhibition potential of M-ALPHA, using high-performance liquid chromatography coupled to high resolution tandem mass spectrometry (HPLC-HRMS/MS). Results: Four metabolites of M-ALPHA were detected including one phase I and three phase II metabolites, resulting from demethylenation followed by subsequent methylation or glucuronidation. For N-methyl-cyclazodone, one phase I metabolite formed via N-demethylation was identified. The primary enzymes involved in M-ALPHA metabolism were CYP2B6 and CYP2D6. Notably, M-ALPHA inhibited these enzymes to a strong or moderate extent, respectively. In contrast, the metabolism of N-methyl-cyclazodone was primarily mediated by CYP2A6. PPB studies indicated low-to-moderate binding for both compounds, suggesting that significant protein-binding interactions are unlikely. Conclusions: As M-ALPHA only formed metabolites that overlapped with those of MDMA, differing only by minor retention time shifts, reliable HPLC-HRMS/MS-based identification may be challenging in clinical and forensic toxicology settings as well as doping analysis. Furthermore, drug–drug interactions following polydrug use cannot be excluded for either NPS, particularly when co-ingested with other CYP substrates metabolized by the same isoforms. Full article

The DNA methyltransferases inhibitor 5-azacytidine (5AzC), clinically used to treat hematopoietic malignancies, can elevate genomic mutational burden, raising safety concerns. To define the epigenetic specificity and mutagenic consequences of 5AzC, we performed multi-omics analyses in Neurospora crassa. Our data showed that 5AzC caused a non-selective, genome-wide reduction in both 5-methylcytosine (5mC; ~50% decrease) and the heterochromatin mark H3K9me3 (~65% decrease), indicating broad off-target demethylation that may transiently benefit therapy yet compromise genome stability. Whole-genome sequencing (WGS) revealed a ~290-fold increase in mutation rate under 5AzC, with a pronounced C->G transversion bias, a spectrum typically associated with higher functional burden. Strikingly, 5AzC-induced mutations were enriched in H3K9me3-marked domains, particularly pericentromeric regions characterized by low 5mC but high H3K9me3. Genetic analyses showed that the loss of DNA methyltransferase DIM-2 reduced 5AzC-induced mutations by ~64%, while individual or combined knockout of the histone methyltransferase DIM-5 with DIM-2 led to an 85% reduction. Thus, mutagenesis was markedly amplified by DIM-2 and DIM-5, with DIM-2 activity dependent on DIM-5. Collectively, DIM-2 and DIM-5 accounted for nearly all A/T-site and ~80% of G/C-site mutations. These results reveal that 5AzC drives genome-wide loss of 5mC and H3K9me3, with mutagenesis preferentially targeting H3K9me3-enriched regions via DIM-2 and DIM-5. This work clarifies a mechanistic basis for 5AzC-associated genomic risk and highlights strategies for next-generation epigenetic therapies that preserve heterochromatin integrity while minimizing mutational load. Full article

Aflatoxin B1 (AFB1) is a potent mycotoxin threatening food and feed safety. Here, we report the identification and characterization of a Bacillus safensis-derived multicopper oxidase (BsaMCO) capable of efficient AFB1 detoxification. Recombinant BsaMCO exhibited robust in vitro activity, achieving >78% degradation of AFB1 under 24 h incubation at 37 °C. Optimization experiments revealed that enzyme concentration, pH, temperature, metal ions, and electron acceptors significantly influenced degradation efficiency, defining an operational window suitable for practical applications. LC–MS profiling suggested the presence of transformation products tentatively consistent with oxidative demethylation to aflatoxin P1 (AFP1) and with the formation of AFG2a-like products through subsequent hydration- and oxidation-related transformations. Molecular docking and 100 ns all-atom molecular dynamics (MD) simulations demonstrated stable binding of AFB1 in the T1 copper pocket. Van der Waals and electrostatic interactions, together with a persistent hydrogen bond at Gly323, facilitated single-electron transfer through the intramolecular T2/T3 copper cluster. Principal component and Gibbs free energy analyses confirmed a low-energy, stable conformational ensemble. HepG2 cell assays indicated that BsaMCO-degraded products substantially reduced cytotoxicity and apoptosis compared with native AFB1. Simulated feed experiments further validated enzymatic AFB1 degradation, with approximately 53% reduction after 24 h. Collectively, these findings establish BsaMCO as a safe and effective biocatalyst for AFB1 detoxification, providing mechanistic, structural, and cellular evidence supporting its application in food and feed safety. Full article

Triptolide (TPL), the core active component of the traditional Chinese medicinal herb Tripterygium wilfordii Hook F (TwHF), possesses a wide spectrum of pharmacological activities, including anti-inflammatory, neuroprotective, immunosuppressive, and anti-tumor activities. However, its clinical application is severely limited by significant reproductive toxicity, the mechanism of which remains poorly understood. Using an integrated analysis of MeRIP-seq and mRNA-seq data, coupled with experimental validation in HTR-8/SVneo cells, we systematically elucidated the molecular mechanism by which TPL induces trophoblast cell injury. Our findings revealed that TPL significantly altered intracellular N⁶-methyladenosine (m⁶A) modification and gene expression profiles, with 1774 genes displaying hypomethylation concurrent with mRNA upregulation. According to the functional enrichment analysis, these genes showed significant enrichment in several key pathways associated with reproduction, including autophagy, DNA damage response, mitochondrial outer membrane, and positive regulation of apoptotic process. Molecular docking further demonstrated direct and stable binding of TPL to key m⁶A regulators, leading to specific demethylation of targets including E2F1 and PPP1CC. This study uncovers a novel post-transcriptional mechanism where TPL disrupts m⁶A modification, thereby perturbing essential trophoblast functions and driving reproductive toxicity. Full article

Reproductive aging is characterized by progressive decline in ovarian reserve, reduced oocyte competence, and impaired endocrine coordination. Although these phenotypic changes are well documented, the molecular mechanisms that integrate aging-associated stress signals into coordinated ovarian dysfunction remain incompletely understood. Increasing evidence indicates that DNA methylation remodeling is closely associated with ovarian aging. Rather than representing isolated promoter-specific events, age-related methylation alterations may reflect progressive imbalance between DNA methyltransferases (DNMTs) and TET-mediated demethylation. Stress-responsive DNMT/TET dysregulation has been linked to distributed epigenetic remodeling across regulatory elements governing PI3K–AKT, TGF-β/SMAD, metabolic, and DNA damage response pathways in ovarian cell populations. We propose a network-level framework in which methylation drift preferentially affects highly connected regulatory hubs, potentially reducing transcriptional robustness and intercellular coordination within the follicular microenvironment. However, current human data remain largely correlative, and functional validation is required to determine whether methylation remodeling acts as a driver, amplifier, or biomarker of ovarian aging. Finally, we discuss translational implications, including circulating cell-free DNA signatures and epigenetic clock models, while emphasizing the importance of cell type-resolved and longitudinal studies. Collectively, the available evidence supports a model in which progressive DNMT/TET imbalance is associated with distributed pathway-level regulatory instability during ovarian aging. Full article

Background/Objectives: Eudesmin is a tetrahydrofurofuranoid lignan known for its diverse pharmacological activities, including anti-tumor, anti-inflammatory, and neuroprotective effects. However, its metabolism has not been well characterized. Methods: This study examined the in vitro metabolism of eudesmin using human and mouse hepatocytes, human liver microsomes, and recombinant drug-metabolizing enzymes. Liquid chromatography–high-resolution mass spectrometry combined with ion identity molecular networking enabled the comprehensive visualization and annotation of eudesmin metabolites. Results: Eudesmin exhibited moderate metabolic stability in human and mouse hepatocytes, with half-lives of 181.0 min and 132.9 min, and intrinsic clearance values of 27.7 mL/min/kg and 154.0 mL/min/kg, respectively. Incubation of eudesmin with human hepatocytes resulted in the formation of 13 metabolites, including five phase I metabolites (M1–M5) and eight phase II conjugates. Phase I metabolism was dominated by O-demethylation of the 3,4-dimethoxyphenyl moieties, yielding mono-O-demethylated (M1 and M2) and di-O-demethylated metabolites (M3 and M4), as well as a hydroxylated metabolite (M5). Enzyme phenotyping, kinetic analyses, and chemical inhibition experiments identified cytochrome P450 2C9 (CYP2C9) as the major contributor to O-demethylation, with additional contributions from CYP2C19, CYP2C8, CYP3A4, and CYP3A5, whereas hydroxylation was mediated primarily by CYP3A4 and CYP3A5. The O-demethylated metabolites subsequently underwent phase II metabolism, forming glucuronide conjugates of M1–M4 and sulfate conjugates of M1–M3, including a disulfate of M3. Uridine 5′-diphospho-glucuronosyltransferase and sulfotransferase screening revealed the involvement of multiple conjugative enzymes, indicating extensive and distributed phase II metabolism. Specifically, di-O-demethylated metabolites and their conjugates were detected in human hepatocytes but not in mouse hepatocytes, suggesting that the sequential O-demethylation pathway is limited in mice. Conclusions: This study characterizes eudesmin metabolism, with CYP2C9-mediated O-demethylation and significant species differences between humans and mice, and provides a basis for its further pharmaceutical development. Full article

Drought stress is a major abiotic factor limiting maize yield and stability. Although Jumonji C (JMJ) histone demethylases are known to regulate plant growth, development, and stress responses, their systematic characterization in maize has remained limited. Here, 27 ZmJMJ genes were identified in the maize genome through BLAST and conserved-domain analyses and classified into five subfamilies: JMJD6, KDM3/JHDM2, KDM4/JHDM3, KDM5/JARID1, and JmjC domain-only. Members within the same subfamily showed similar physicochemical properties, domain composition, and motif distribution, whereas clear divergence was observed among subfamilies. Chromosomal mapping revealed that ZmJMJ genes were unevenly distributed across nine chromosomes, with two interchromosomal homologous gene pairs, suggesting roles for segmental and/or whole-genome duplication in family expansion. Promoter analysis indicated widespread enrichment of elements related to light responsiveness, growth and development, and hormone and stress responses. Expression profiling showed that most ZmJMJ genes were highly expressed in leaves, while several displayed tissue specificity. Under drought stress, ZmJMJ17a, ZmJMJ17b, ZmJMJ28, and ZmJMJ32 were significantly induced, highlighting them as promising candidates for functional studies and molecular breeding for drought tolerance in maize. This study provides a foundation for elucidating the evolution and functions of the ZmJMJ family and identifies candidate genes for drought-related functional validation and molecular breeding. Full article

Background/Objectives: Early embryonic arrest during the cleavage stage (days 2–4) accounts for a substantial proportion of developmental failure in in vitro fertilization. This phenomenon remains poorly understood at the molecular level, even in chromosomally normal embryos identified by preimplantation genetic testing. This review aims to redefine cleavage-stage arrest from a passive energy deficit to a checkpoint-regulated endpoint caused by inadequate coordination among metabolism, transcriptome integrity, and stress-response pathways. Methods: We integrate evidence from long-read transcriptomics, metabolomics, epigenetics, and immunobiology relevant to pre-blastocyst development. These data are assembled into a unifying mechanistic framework and a clinically oriented stratification model, together with candidate multimodal readouts for early classification. Results: We propose a three-axis model linking: (i) metabolic–epigenetic insufficiency, including defective histone lactylation and impaired alpha-ketoglutarate-dependent DNA demethylation; (ii) isoform-level abnormalities, including intron retention and retrotransposon activation within a hidden transcriptomic landscape better resolved by long-read sequencing; and (iii) stress-related immune signaling, in which NLRP7 links alternative splicing and DNA-damage-response dysfunction with mitochondrial stress and p53-associated arrest. Within this framework, we distinguish three molecular arrest states: an early transition failure marked by defective maternal-to-embryonic reprogramming and severe splicing disruption; a metabolically quiescent state that may retain a limited rescue window; and a later stress-associated state characterized by senescence-like features, oxidative stress, and broad transcriptomic and genomic instability. Conclusions: Early embryo arrest should no longer be viewed as a nonspecific developmental failure, but as a mechanistically stratifiable condition with distinct metabolic, transcriptomic, and stress-associated trajectories. A diagnostic platform combining fluorescence lifetime imaging microscopy, long-read sequencing, and digital polymerase chain reaction may improve early mechanistic classification, help identify embryos with possible reversibility, and reduce uncertainty in embryo selection during in vitro fertilization. Full article

The secondary effluent from printing and dyeing wastewater contains recalcitrant organic pollutants, such as azo dye derivatives. Their persistence in aquatic environments not only creates ecological risks but also hampers the high-value reuse of reclaimed water. This study investigated the influence of typical binary anions on the degradation performance of low-concentration azo dye wastewater using a Ti/RuO₂-IrO₂ anode electrochemical oxidation system. The results demonstrated that maximum COD removal efficiency could reach 50.22%, and the controlling factors synergistically regulated the contribution and competition between Reactive Chlorine Species and free radicals. This led to a characteristic “rapid rise–decline–slow rebound” phenomenon in the COD removal rate, with the inflection points co-influenced by the current density, conductivity, and binary anion ratio of the electrochemical process. Furthermore, it alters the degradation pathway of the azo dye to “azo bond cleavage → demethylation/desulfonation → dehydroxylation/deamination oxidation → benzene ring opening”. Within a fixed duration of 60 min, the Response Surface Methodology model identified the optimal COD degradation conditions as follows: current density of 19.72 mA/cm², Cl⁻/SO₄²⁻ ratio of 5.40, and conductivity of 8.30 mS/cm. This research elucidates the differences between the electrochemical oxidation degradation pathway of low-concentration azo dye wastewater under the regulation of typical binary anions and the conventional pathway. It also reveals the regulatory effects of current density, conductivity, and binary anion ratio on the degradation patterns. Full article

Maclekarpine E is a minor alkaloid from Macleaya species with reported in vitro anti-inflammatory activity, but its in vivo metabolism remains unexplored. This study investigated the metabolic fate of maclekarpine E in rats and evaluated the potential pharmacological relevance of its metabolites. Maclekarpine E was orally administered to male Sprague-Dawley rats (250 mg/kg). Plasma, urine and feces were collected and analyzed by UPLC-Q-TOF-MS/MS. CYP phenotyping was performed using recombinant human enzymes. Molecular docking against ABCG2 and ABCC2 was conducted to assess potential interactions of all fecal compounds with these efflux transporters. Network pharmacology was employed to predict potential anti-ulcerative colitis-related targets of the metabolites, generating hypotheses for future experimental validation. Nineteen phase I metabolites were identified. Biotransformations included ring-opening, demethylation and oxidation. All 19 metabolites were detected in feces, nine in plasma and two in urine. No phase II conjugates were observed. CYP2C19 was the only significantly active isoform under the tested conditions, mediating approximately 16.5% substrate depletion (p < 0.05). All 20 fecal compounds bound ABCG2 (ΔG < −5.0 kcal/mol); 19 bound ABCC2. Network pharmacology yielded 57 overlapping targets with ulcerative colitis, enriched in PI3K-Akt and MAPK pathways. This study provides the first comprehensive metabolic profile of maclekarpine E in rats. The compound undergoes CYP2C19-mediated oxidation and is predominantly excreted into feces. Its fecal metabolites are potential ABCG2/ABCC2 substrates and may target UC-associated pathways based on network pharmacology predictions, warranting further experimental validation. Full article

Oxidative stress is a hallmark of carcinogenesis, yet the epigenetic mechanisms linking the lifestyle-based Oxidative Balance Score (OBS) to cancer risk remain poorly understood. This study investigated the epigenetic bridge between OBS and pan-cancer susceptibility using a multi-cohort approach integrating population-based and cancer genomic data. We calculated OBS based on 16 dietary and lifestyle factors (including dietary fiber, vitamins, minerals, physical activity, smoking, alcohol, and BMI) for 2749 participants from the Korean Genome and Epidemiology Study (KoGES) and identified OBS-associated CpG sites via epigenome-wide association analysis. These markers were validated against The Cancer Genome Atlas (TCGA) pan-cancer dataset using a novel Hybrid Pi-score (HyPi) to quantify the directional consistency between OBS-driven methylation in healthy individuals and cancer-specific epigenetic alterations across three clinical comparisons: normal vs. tumor, survival outcomes, and tumor stage. We observed profound sex-specific epigenetic signatures, with zero overlap in the top 200 OBS-associated CpG sites between males and females, underscoring fundamental sexual dimorphism in oxidative stress-epigenome interactions. Notably, the top 20 OBS-associated CpGs demonstrated strong directional consistency with multiple cancer types in TCGA, particularly in kidney renal clear cell carcinoma and lung adenocarcinoma, exhibiting methylation patterns inversely correlated with tumorigenesis. Mechanistically, these findings support the role of one-carbon metabolism and vitamin C-dependent DNA demethylation pathways in mediating OBS effects. Our study provides the first evidence of an epigenetic link between lifestyle-based oxidative balance and pan-cancer risk, highlighting the utility of the HyPi score as a novel sex-specific predictive biomarker for cancer prevention. These results suggest that optimizing oxidative balance through precision nutrition may epigenetically modulate cancer susceptibility, opening new avenues for personalized prevention strategies. Full article

Triazolopyrimidine sulfonamide herbicides, a prominent class of acetohydroxyacid synthase (AHAS) inhibitors, are exceptionally effective in controlling weeds in agricultural settings. To overcome metabolic resistance caused by the 5-demethylation of pyroxsulam, we sought to replace its 5-methoxy group on the triazolopyrimidine ring with alkyl substituents. This led to the synthesis of a series of N-(7-oxo-4,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidin-2-yl)arylsulfon-amides, which displayed significant structural diversification potential, culminating in the identification of the herbicidal hit compound I-20. However, the suboptimal lipophilicity compromised its herbicidal efficacy. To rectify this limitation, we modified the 7-carbonyl group to a tert-butoxy group, resulting in the highly active compound I-29. This compound demonstrated herbicidal activity comparable to or exceeding that of penoxsulam against various tested weeds, establishing it as a promising new lead compound and a candidate herbicide for further investigation. Subsequent studies revealed that I-29 exhibited a receptor binding mode and herbicidal activity profiles that closely aligned with those of penoxsulam. Moreover, its spatial structure was found to be even more conducive to inhibiting flavin adenine dinucleotide (FAD)-mediated AHAS activity. This research not only sheds light on addressing the challenge of 5-demethylation metabolic resistance in triazolopyrimidine sulfonamide herbicides but also offers new avenues for the development of AHAS-inhibiting triazolopyrimidine sulfonamide herbicides. Full article

Background/Objectives: Previous studies have suggested that lifestyle intervention (LSI) therapies involving diet and exercise can modulate DNA methylation; however, whether this occurs in severely obese hypogonadal men undergoing weight loss from diet and exercise remains unclear. Methods: In this study, we investigated the effects of weight loss from diet and exercise on global DNA methylation as well as on the mRNA expression of specific demethylation enzymes, DNMT1, DNMT3A, and DNMT3B—in peripheral blood mononuclear cells (PBMCs) and DNA methylation markers in DNA of severely obese hypogonadal men. This is a secondary analysis of samples of severely obese (body mass index of ≥35 kg/m²) hypogonadal men undergoing weight loss from diet and exercise in addition to an aromatase inhibitor (anastrozole) or placebo for a total of 12 months. Results: LSI therapy significantly reduced global DNA methylation and 5-methylcytosine (5-mC) levels, decreased DNMT1, DNMT3A, and DNMT3B (p < 0.05) mRNA levels and markedly decreased CEBPα, FTO, and PPARγ mRNA expression. The reduction in global methylation was independent of aromatase inhibitor use. Conclusions: In summary, our findings suggest that LSI induces epigenetic modifications in leukocytes, possibly through the regulation of DNMT gene expression. Future studies are warranted to clarify the mechanistic pathways linking lifestyle-induced epigenetic alterations to metabolic health outcomes. Full article

DNA polymerase beta (Polβ) is a 39 kDa, single polypeptide enzyme that possesses both gap tailoring and nucleotidyl transferase activity and is the key polymerase involved in base excision repair (BER) and the final steps of active gene demethylation. We demonstrated that residues in the mouse Polβ protein, L301 and V303, are critical for Polβ’s interaction with the BER scaffolding protein X-ray repair cross-complementing 1 (XRCC1), and mutation of these residues impairs Polβ’s ability to bind to XRCC1, negatively impacting BER complex assembly. We developed Polβ^{L301R-V303R/L301R-V303R} knock-in mice to explore how defects with this essential protein complex impact genome stability in the mouse. We found these mice to be viable and fertile yet exhibited a modest reduction in body weight. Here, we examined the protein and mRNA levels in tissues from wild-type (WT), heterozygous (HET), and homozygous (HOM) Polβ^{L301R-V303R/L301R-V303R} mice and the derived fibroblast cell lines. We show that HOM mice have significantly diminished Polβ protein levels, as compared to WT mice, in several tissues, yet Polβ mRNA levels were not significantly different, suggesting the decreased levels of Polβ protein could not be attributed to lower gene expression. Upon examination of Polβ stability in mouse ear fibroblasts derived from WT and HOM mice, results are consistent with human cell studies that the Polβ^L301R-V303R protein is unstable and undergoes proteasome-mediated degradation. Finally, we evaluated WT, and HOM, liver and brain genomic DNA samples for 5-methylcytosine/5-hydroxymethylcytosine (5mC/5hmC) levels by nanopore sequencing to investigate the impact of suppressed Polβ protein levels on active gene demethylation. As expected, we found tissue-specific trends in methylation, when comparing the brain and liver. However, we were unable to discern substantial differences in methylation levels between WT and HOM mice, suggesting that in the absence of external stressors, low Polβ levels do not impact methylation patterns. Full article

The human ALKBH gene family comprises nine Fe²⁺/α-ketoglutarate-dependent dioxygenases that catalyze the oxidative demethylation of DNA, RNA, and proteins, thereby influencing key cellular processes. Consequently, dysregulation of these enzymes has been implicated in various human diseases, particularly cancer. Although the transcriptomic profiles of certain members (e.g., ALKBH8, FTO) have been characterized, a comprehensive analysis of the entire ALKBH family remains unclear. In the present study, we investigated the alternative splice variants of the ALKBH genes through direct RNA sequencing across cancerous and non-cancerous cell lines. Novel splicing events were validated by NGS, while RT-qPCR was employed to assess transcript abundance and expression patterns. Additionally, in silico analysis was performed to predict the coding potential of the detected transcripts. Results: Bioinformatics analysis revealed previously uncharacterized alternative transcripts for the human ALKBH gene family members. Expression profiling demonstrated distinct expression patterns between cancerous and non-malignant cells, suggesting a potential role of these demethylases in tumor biology. The investigation of their coding capacity revealed that most of the newly detected transcripts were predicted to encode protein isoforms, highlighting the structural and predicted coding potential of the ALKBH family. Conclusions: Our findings provide the first comprehensive overview of the transcriptional diversity within the human ALKBH gene family. These results enhance our understanding of the demethylation mechanisms and their dysregulation in cancer. Full article