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Several studies have associated the epitranscriptomic RNA modification of N6-methyladenosine (m 6 A) with cardiovascular diseases; however, how m 6 A modification affects cardiomyocyte pyroptosis after myocardial infarction (MI) remains unknown. Here, we showed that AlkB homolog 5 (ALKBH5), an m 6 A demethylase, is crucial in cardiomyocyte pyroptosis after MI. We used MI rat and mouse models, a cell hypoxia model of rat primary cardiomyocytes (RCMs), and rat embryonic ventricle cell line (H9c2) to explore the functional role of m 6 A modification and ALKBH5 in the heart and cardiomyocytes. Using plasmids and small interfering RNAs, the expressions of ALKBH5 and NOD-like receptor family pyrin domain-containing 3 (NLRP3) were determined to study their functions in regulating cardiomyocyte m 6 A and pyroptosis, respectively. We characterized the role of ALKBH5, which exhibited elevated expression in the ischemic heart tissue of rats and mice and hypoxic cardiomyocytes (RCMs and H9c2 cells). ALKBH5 knockdown alleviated hypoxia-induced H9c2 cell pyroptosis by inhibiting NLRP3 inflammasome activation, whereas ALKBH5 overexpression had the opposite effect. NLRP3 knockdown alleviated hypoxia-induced H9c2 cardiomyocyte pyroptosis by inhibiting ALKBH5 expression, whereas NLRP3 overexpression had the opposite effect. Mechanistically, ALKBH5 mediated m 6 A modification of NLRP3 mRNA in an IGF2BP2-dependent manner, and NLRP3, as a nuclear transcription factor, regulated the ALKBH5 transcription process. Targeting the ALKBH5-NLRP3 loop with the small-molecule inhibitors alleviated cardiomyocyte pyroptosis. Our results highlight that ALKBH5-NLRP3 forms a positive feedback loop that promotes cardiomyocyte pyroptosis after MI. Therefore, inhibiting the ALKBH5-NLRP3 loop is a potential strategy for treating cardiovascular diseases., Competing Interests: Declaration of competing interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in, or the review of, the manuscript entitled., (Copyright © 2024 Elsevier B.V. All rights reserved.)

N6-methyladenosine (m6A) is one of the most prevalent epigenetic modifications in eukaryotic cells. It regulates RNA function and stability by modifying RNA methylation through writers, erasers, and readers. As a result, m6A plays a critical role in a wide range of biological processes. Inflammation is a common and fundamental pathological process. Numerous studies have investigated the role of m6A modifications in inflammatory diseases. This review highlights the mechanisms by which m6A contributes to inflammation, focusing on pathogen-induced infectious diseases, autoimmune disorders, allergic conditions, and metabolic disorder-related inflammatory diseases., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

N6-methyladenosine (m6A) is the most prevalent RNA modification and a multifaceted regulator capable of affecting various aspects of mRNA metabolism, thereby playing important roles in numerous physiological processes. However, it is still unknown whether, when, and to what extent m6A modulation are implicated in the immune response of an economically important aquaculture fish, half-smooth tongue sole (Cynoglossus semilaevis). Herein, we systematically profiled and characterized the m6A epitranscriptome and transcriptome in C. semilaevis after the infection of Vibrio anguillarum. We demonstrated that m6A could be modulated as early as 4-h post infection (hpi), and the overall intensity of m6A methylation was enhanced following infection. Both conservative and novel motifs were uncovered from the m6A modification sites. Furthermore, differentially m6A methylated genes (DMGs) and differentially expressed genes (DEGs) were identified, and functional enrichment revealed multiple immune-related pathways, especially the FoxO signaling pathway which showed significance in every comparison. Joint analysis highlighted the remarkedly dynamic role of m6A on gene expression, i.e. early on, m6A mainly prioritized the down-regulation of specific genes, and later, it switched gears to promote expression of another set of genes. Moreover, key candidate genes, mainly involved in immunity and energy metabolism, were identified. Validations were performed by qPCR and MeRIP-qPCR. To our limited knowledge, this is the first study comprehensively characterizing the global m6A atlas in aquaculture fish species. The presented results provide new insights into the dynamics of m6A modifications in the transcriptome of the half-smooth tongue sole following bacterial infection, and further studies are warranted to elucidate the functional significance of these changes in depth., Competing Interests: Declaration of competing interest No potential conflict of interest was reported by the authors., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Diabetic retinopathy (DR) is the major ocular complication of diabetes caused by chronic hyperglycemia, which leads to incurable blindness. Currently, the effectiveness of therapeutic interventions is limited. This study aimed to investigate the function of piezo-type mechanosensitive ion channel component 1 (PIEZO1) and its potential regulatory mechanism in DR progression. PIEZO1 expression was up-regulated in the retinal tissues of streptozotocin-induced diabetic mice and high-glucose (HG)-triggered Müller cells. Functionally, the knockdown of PIEZO1 improved the abnormal retinal function of diabetic mice and impeded inflammatory cytokine secretion and gliosis of Müller cells under HG conditions. Mechanistic investigations using RNA immunoprecipitation-real-time quantitative PCR, methylation RNA immunoprecipitation-real-time quantitative PCR, and luciferase reporter assays demonstrated that PIEZO1 was a downstream target of methyltransferase-like 3 (METTL3). METTL3-mediated N 6 -methyladenosine (m 6 A) modification within the coding sequence of PIEZO1 mRNA significantly shortened its half-life. In HG-stimulated cells, there was a negative regulatory relationship between PIEZO1 and YTH (YT521-B homology) domain family 2 (YTHDF2), a recognized m 6 A reader. The loss of YTHDF2 resulted in an extended half-life of PIEZO1 in cells with overexpression of METTL3, indicating that the effect of METTL3 on the mRNA stability of PIEZO1 was dependent on YTHDF2. Taken together, this study demonstrated the protective role of the PIEZO1 silencing in DR development, and that the degradation of PIEZO1 mRNA is accelerated by METTL3/YTHDF2-mediated m 6 A modification., Competing Interests: Disclosure Statement None declared., (Copyright © 2025 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Acute myelogenous leukemia (AML)-derived mesenchymal stem cells (MSCs) (AML-MSCs) have been identified to play a significant role in AML progression. The functions of MSCs mainly depend on their paracrine action. Here, we investigated whether AML-MSCs functioned in AML cells by transferring METTL14 (Methyltransferase 14) into AML cells via exosomes. Functional analyses were conducted using MTT assay, 5-ethynyl-2-deoxyuridine assay and flow cytometry. qRT-PCR and western blot analyses detected levels of mRNAs and proteins. Exosomes (exo) were isolated from AML-MSCs by ultracentrifugation. The m6A modification profile was determined by methylated RNA immunoprecipitation (MeRIP) assay. The interaction between Insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) and Rho Kinase 1 (ROCK1) was validated using RIP assay. AML-MSCs incubation promoted the proliferation and radioresistance in AML cells. Moreover, AML-MSCs incubation led to increases in m6A levels and METTL14 levels in AML cells. METTL14 was transferred into AML cells by packaging into exosomes of AML-MSCs. The knockdown of METTL14 in AML-MSCs exosomes could reduce the proliferation and radioresistance in AML cells. Mechanistically, METTL14 induced ROCK1 m6A modification and stabilized its expression by an m6A-IGF2BP3-dependent mechanism. Rescue assay showed that ROCK1 overexpression reversed the inhibitory effects of METTL14 silencing in AML-MSCs exosomes on AML cell proliferation and radioresistance. Exosome-shuttled METTL14 from AML-MSCs promoted proliferation and conferred radioresistance in AML cells by stabilizing ROCK1 expression via an m6A-IGF2BP3-dependent mechanism., (© 2024 Wiley Periodicals LLC.)

Background: Breast cancer is the most frequently diagnosed cancer among women worldwide with high morbidity and mortality. Previous studies have indicated that RNA-binding motif protein-15 (RBM15), an N6-methyladenosine (m6A) writer, is implicated in the growth of breast cancer cells. Herein, we aimed to explore the function and detailed mechanism of RBM15 in breast cancer., Methods: In this research, UALCAN databases were applied to analyze the expression of RBM15 or Karyopherin-2 alpha (KPNA2) in BRCA. RBM15 and KPNA2 mRNA levels were determined using real-time quantitative polymerase chain reaction (RT-qPCR) assay. RBM15, KPNA2, and Programmed cell death ligand 1 (PD-L1) protein levels were measured using western blot. Cell proliferation, migration, and invasion were assessed using 5-ethynyl-2'-deoxyuridine (EdU) and Transwell assays. The biological role of RBM15 on breast cancer tumor growth was verified using the xenograft tumor model in vivo. Effects of breast cancer cells on the proliferation and apoptosis of CD8 + T cells were analyzed using flow cytometry. Interaction between RBM15 and KPNA2 was validated using methylated RNA immunoprecipitation (MeRIP) and dual-luciferase reporter assays., Results: RBM15 and KPNA2 were highly expressed in breast cancer tissues and cell lines. Furthermore, RBM15 silencing might suppress breast cancer cell proliferation, migration, invasion, and lymphocyte immunity in vitro, as well as block tumor growth in vivo. At the molecular level, RBM15 might improve the stability and expression of KPNA2 mRNA via m6A methylation., Conclusion: RBM15 might contribute to the malignant progression and immune escape of breast cancer cells partly by modulating the stability of KPNA2 mRNA, providing a promising therapeutic target for breast cancer., Competing Interests: Disclosure The authors have stated that they have no conflicts of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

N6‑methyladenosine (m 6 A) is one of the most universal, abundant and conserved types of internal post‑transcriptional modifications in eukaryotic RNA, and is involved in nuclear RNA export, RNA splicing, mRNA stability, gene expression, microRNA biogenesis and long non‑coding RNA metabolism. AlkB homologue 5 (ALKBH5) acts as a m6A demethylase to regulate a wide variety of biological processes closely associated with tumour progression, tumour metastasis, tumour immunity and tumour drug resistance. ALKBH5 serves a crucial role in human digestive system tumours, mainly through post‑transcriptional regulation of m 6 A modification. The present review discusses progress in the study of the m6A demethylase ALKBH5 in gastrointestinal tract cancer, summarizes the potential molecular mechanisms of ALKBH5 dysregulation in gastrointestinal tract cancer, and discusses the significance of ALKBH5‑targeted therapy, which may provide novel ideas for future clinical prognosis prediction, biomarker identification and precise treatment.

Myasthenia gravis (MG) is an autoimmune disease mediated by autoantibodies. The important roles of circRNAs modified by m6A methylation have been reported in the pathogenesis of other autoimmune diseases, but remain unclear in MG. To address this point, we collected peripheral blood mononuclear cells from six MG patients and six healthy controls and performed m6A‑circRNA epitranscriptomic microarray and RNA sequencing. Differentially m6A-modified circRNAs and differentially expressed genes (DEGs) were analyzed. A network was constructed containing 17 circRNAs, 30 miRNAs, and 34 DEGs. The GSE85452 dataset was downloaded. DEGs that were differentially expressed in the GSE85452 dataset were selected as seed genes. Finally, four candidate m6A-modified circRNAs (hsa_circ_0084735, hsa_circ_0018652, hsa_circ_0025731, and hsa_circ_0030997) were identified through a random walk with restart. We found that they had different degree correlations with different immune cells. The results of MeRIP-qPCR showed that the m6A methylated levels of hsa_circ_0084735 and hsa_circ_0025731 were downregulated in MG patients, while the other two circRNAs were not significantly different between MG and control group. For the first time, we explored the pathogenesis of MG at the epigenetic transcriptome level. Our results will open new perspectives for MG research and identify potential biomarkers and therapeutic targets for MG., Competing Interests: Declarations. Ethics Approval and Consent to Participate: The studies involving human participants were reviewed and approved by the Ethics Committee of Tangdu Hospital, the Fourth Military Medical University (202006–23). The patients/participants provided their written informed consent to participate in this study. Consent for Publication: Not applicable. Competing Interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Whether maternal hypertension contributes to the enhanced susceptibility to vascular remodeling in adult offspring through epigenetic mechanisms remains unclear. We aimed to address this gap in the literature using a transgenerational mouse model., Methods: Gestational hypertension was induced in pregnant mice using chronic angiotensin II infusion. Blood pressure was monitored using the tail-cuff method. Two months post-delivery, an N 6 -methyladenosine epitranscriptomic microarray analysis was performed on the carotid arteries of second-generation mice. A unilateral carotid artery injury model was used to study the postinjury vascular response in vivo. Furthermore, carotid ultrasonography, immunohistochemistry, and molecular biological parameters were assessed in adult offspring., Results: Exposure to maternal hypertension decreased the birth weight of live pups and increased the fetal death rate. Compared with normal offspring, adult offspring with hypertension had wire-induced injury that led to greater vascular remodeling, which was associated with aggravated inflammation imbalance, fibrosis, and oxidative stress. In addition, aberrant N 6 -methyladenosine methylation, increased N 6 -methyladenosine levels, and increased METTL3 (methyltransferase-like 3) expression were detected in the vessels of offspring with hypertension. Maternal METTL3 deficiency increased the birth weight of live pups with hypertension, improved vascular dysfunction, and alleviated vascular inflammation in adult offspring with hypertension after injury., Conclusions: Maternal hypertension can induce transgenerational transmission of enhanced susceptibility to vascular remodeling, and the possible underlying mechanism is associated with altered METTL3-mediated N 6 -methyladenosine methylation. Therefore, this study reveals the role of epigenetic effects across generations and provides new insights into vascular remodeling causes., Competing Interests: None.

Non-small cell lung cancer (NSCLC) has emerged as one of the most prevalent malignancies worldwide. N6-methyladenosine (m 6 A) methylation, a pervasive epigenetic modification in long noncoding RNAs (lncRNAs), plays a crucial role in NSCLC progression. Here, we report that m 6 A modification and the expression of the lncRNA stem cell inhibitory RNA transcript (SCIRT) was significantly upregulated in NSCLC tissues and cells. Functional analysis revealed that SCIRT enhanced NSCLC cell proliferation, migration, invasion, and epithelial‒mesenchymal transition. The m 6 A modification of SCIRT can be installed by METTL3, which enhanced the stability of this lncRNA. Notably, SCIRT overexpression in response to DNA double-strand breaks (DSBs) sensitized cells to camptothecin (CPT) and impairs DNA homologous recombination repair. SCIRT directly interacted with SFPQ in vitro and was primarily localized in the nucleus. Furthermore, ectopic SCIRT expression upregulated SFPQ and activated the PI3K/Akt pathway following CPT treatment, suggesting an unexpected role of SCIRT in facilitating SFPQ-mediated DSB repair. In brief, our findings highlight the oncogenic role of SCIRT in NSCLC by binding SFPQ and activating PI3K/Akt signaling, presenting a promising therapeutic target for personalized NSCLC treatment., Competing Interests: Declarations. Ethics approval and consent to participate: This study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the Ethics Committee of Harbin Medical University Cancer Hospital. All participants involved in these studies provided their informed consent. Consent to publish: Informed consent was obtained from all individual participants included in the study. Competing interests: The authors declare that they have no conflict of interest., (© 2025. The Author(s).)

Esophageal cancer is a major malignancy with a high incidence and poor prognosis. To elucidate the mechanisms underlying its progression, particularly with respect to cell division and spindle orientation, we investigated the role of m6A modifications and the centrosomal protein CEP170. Using m6A-seq and RNA-seq of esophageal cancer tissues and adjacent normal tissues, we identified significant alterations in m6A modifications and gene expression, highlighting the upregulation and m6A enrichment of CEP170 in tumor tissues. Functional assays, including cell cycle synchronization, qPCR, immunoblotting, immunofluorescence, coimmunoprecipitation, methylated RNA immunoprecipitation, and cell proliferation assays, demonstrated that CEP170 plays a critical role in mitotic progression and spindle orientation. m6A-seq and RNA-seq revealed significant alterations in m6A modifications and gene expression in esophageal cancer. CEP170 was upregulated and highly enriched in m6A modifications in tumor tissues. Functional assays revealed that CEP170 plays a critical role in proper mitotic progression and spindle orientation. Knockdown of CEP170 led to spindle misorientation and impaired the stability of astral microtubules. Additionally, CEP170 affected the localization of the dynein/dynactin motor complex in the cell cortex. METTL3 was upregulated in tumor tissues and regulated CEP170 expression. RNA-seq upon CEP170 depletion revealed that ASPM was significantly downregulated, indicating its involvement as a downstream target of CEP170 in regulating cell proliferation and mitosis. Our findings provide novel insights into the molecular mechanisms by which CEP170 and m6A modifications regulate esophageal cancer progression, revealing that CEP170 is a potential therapeutic target., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Arsenic is a widespread environmental carcinogen, and its carcinogenic mechanism has been the focus of toxicology. N 6 -methyladenosine (m 6 A) binding protein YTH domain family protein 2 (YTHDF2) performs various biological functions by degrading m 6 A-modified mRNAs. However, the m 6 A-modified target mRNA of YTHDF2 in regulating arsenic carcinogenesis remains largely unknown. To explore the effect of YTHDF2 in regulating arsenic carcinogenicity, we exposed the human keratinocyte HaCaT cells to 1 μM sodium arsenite for 50 generations to create a cell model of arsenic carcinogenesis (HaCaT-T). Our results demonstrated that YTHDF2 protein levels were higher in HaCaT-T cells than HaCaT cells, and knockdown of YTHDF2 significantly inhibited arsenic-induced malignant phenotypes. In addition, m 6 A levels in HaCaT-T cells were remarkably elevated, accompanied by abnormal expression of m 6 A methyltransferases and m 6 A demethylases. Mechanistically, YTHDF2 bound to p53-induced death domain protein 1 (PIDD1) mRNA in an m 6 A-dependent manner, thereby promoting the degradation of PIDD1 mRNA. Moreover, the decay of PIDD1 mRNA inhibited the formation of PIDDosome complex that is essential for activating the apoptosis initiator caspase-2, leading to a decrease in caspase-2-dependent mitochondrial apoptosis and subsequently promoting the malignant phenotypes of HaCaT-T cells. Collectively, our study reveals the role of YTHDF2 in arsenic-induced malignant phenotypes of human keratinocytes through direct interaction with PIDD1 mRNA in an m 6 A-dependent manner, which provides new insight into the precise mechanism underlying arsenic-induced skin cancer., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

N 6 -methyladenosine (m 6 A) in eukaryotic RNA is an epigenetic modification that is critical for RNA metabolism, gene expression regulation, and the development of organisms. Aberrant expression of m 6 A components appears in a variety of human diseases. RNA m 6 A modification in Drosophila has proven to be involved in sex determination regulated by Sxl and may affect X chromosome expression through the MSL complex. The dosage-related effects under the condition of genomic imbalance (i.e. aneuploidy) are related to various epigenetic regulatory mechanisms. Here, we investigated the roles of RNA m 6 A modification in unbalanced genomes using aneuploid Drosophila . The results showed that the expression of m 6 A components changed significantly under genomic imbalance, and affected the abundance and genome-wide distribution of m 6 A, which may be related to the developmental abnormalities of aneuploids. The relationships between methylation status and classical dosage effect, dosage compensation, and inverse dosage effect were also studied. In addition, we demonstrated that RNA m 6 A methylation may affect dosage-dependent gene regulation through dosage-sensitive modifiers, alternative splicing, the MSL complex, and other processes. More interestingly, there seems to be a close relationship between MSL complex and RNA m 6 A modification. It is found that ectopically overexpressed MSL complex, especially the levels of H4K16Ac through MOF, could influence the expression levels of m 6 A modification and genomic imbalance may be involved in this interaction. We found that m 6 A could affect the levels of H4K16Ac through MOF, a component of the MSL complex, and that genomic imbalance may be involved in this interaction. Altogether, our work reveals the dynamic and regulatory role of RNA m 6 A modification in unbalanced genomes, and may shed new light on the mechanisms of aneuploidy-related developmental abnormalities and diseases., Competing Interests: SZ, RW, KL, SG, XL, JW, LZ, LS No competing interests declared, (© 2024, Zhang, Wang et al.)

Osteosarcoma (OS) is the most commonly diagnosed primary malignant bone tumor in children and adolescents. Despite significant advancements in therapeutic strategies against OS over the past few decades, the prognosis for this disease remains poor, largely due to its high invasiveness and challenges associated with its treatment. N6-methyladenosine (m6A) modification is one of the most abundant epigenetic modifications of RNAs, and many studies have highlighted its crucial role in OS. This article provides a comprehensive summary and introduction to m6A regulators, including methyltransferases, demethylases, and binding proteins. The article emphasizes how regulated m6A modifications can either promote or inhibit OS. It also delves into the mechanisms by which m6A-modified messenger RNAs (mRNAs) and noncoding RNAs (ncRNAs) participate in signaling pathways such as the Wnt/β-catenin, PI3K/AKT, and STAT3 pathways, and discusses these mechanisms in detail. Given the abnormal expression of m6A regulators in OS, the article also explores their potential applications as biomarkers or therapeutic targets in clinical settings. It is anticipated that this review will provide new insights into the diagnosis and treatment of OS., Competing Interests: Declarations. Competing Interests: The authors have no relevant financial or non-financial interests to disclose. Ethical approval: Not applicable. Consent to participate: Not applicable. Consent to publication: Not applicable., (© 2025. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Fat mass and obesity-associated protein (FTO) was the first m6A demethylase identified, which is responsible for eliminating m6A modifications in target RNAs. While it is well-established that numerous cytosolic and nuclear proteins undergo O-GlcNAcylation, the possibility of FTO being O-GlcNAcylated and its functional implications remain unclear. This study found that a negative correlation between FTO expression and O-GlcNAcylation in patients with myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). The decreased O-GlcNAcylation on FTO can result in diminished m6A modification of SRY-related high mobility group box 4 (SOX4). This led to the promotion of cell apoptosis and inhibition of cell proliferation in MDS/AML. The O-GlcNAcylation of FTO stabilized SOX4 transcripts in an m6A-dependent manner, resulting in increased AKT and MAPK phosphorylation and decreased cell apoptosis. Inhibiting FTO O-GlcNAcylation significantly slowed AML progression in vitro, a finding supported by clinical data in MDS/AML patients. In conclusion, our study highlights the crucial role of FTO O-GlcNAcylation in RNA m6A methylation and the progression of MDS/AML, thereby providing a potential therapeutic avenue for these formidable diseases., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Long-term durable remission in patients with B cell malignancies following chimeric antigen receptor (CAR)-T cell immunotherapy remains unsatisfactory, often due to antigen escape. Malignant B cell transformation and oncogenic growth relies on efficient ATP synthesis, although the underlying mechanisms remain unclear. Here, we report that YTHDF2 facilitates energy supply and antigen escape in B cell malignancies, and its overexpression alone is sufficient to cause B cell transformation and tumorigenesis. Mechanistically, YTHDF2 functions as a dual reader where it stabilizes mRNAs as a 5-methylcytosine (m 5 C) reader via recruiting PABPC1, thereby enhancing their expression and ATP synthesis. Concomitantly, YTHDF2 also promotes immune evasion by destabilizing other mRNAs as an N 6 -methyladenosine (m 6 A) reader. Small-molecule-mediated targeting of YTHDF2 suppresses aggressive B cell malignancies and sensitizes them to CAR-T cell therapy., Competing Interests: Declaration of interests Z.C., X.D., and J.C. have filed a patent application related to this work., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Hydrogen sulfide (H 2 S) is an endogenous gasotransmitter with cardioprotective and antiviral effects. In this work, new cysteine-selective nucleoside-H 2 S-donor hybrid molecules were prepared by conjugating nucleoside biomolecules with a thiol-activatable dithioacetyl group. 5'-Dithioacetate derivatives were synthesized from the canonical nucleosides (uridine, adenosine, cytidine, guanosine and thymidine), and the putative 5'-thio metabolites were also produced from uridine and adenosine. According to our measurements made with an H 2 S-specific sensor, nucleoside dithioacetates are moderately fast H 2 S donors, the guanosine derivative showed the fastest kinetics and the adenosine derivative the slowest. The antioxidant activity of 5'-thionucleosides is significantly higher than that of trolox, but lower than that of ascorbic acid, while intact dithioacetates have no remarkable antioxidant effect. In human Calu cells, the guanosine derivative showed a moderate anti-SARS-CoV-2 effect which was also confirmed by virus yield reduction assay. Dithioacetyl-adenosine and its metabolite showed similar acute cardiac effects as adenosine, however, it is noteworthy that both 5'-thio modified adenosines increased left ventricular ejection fraction or stroke volume, which was not observed with native adenosine., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Glioblastoma (GBM) is the most malignant type of glioma with a very poor prognosis. N6-methyladenosine (m6A) is well-documented to be involved in GBM progression, and FTO is a demethylase. GSTO1 is also associated with tumor progression. This study aimed to investigate the impact of FTO and GSTO1 on GBM progression and the regulation of FTO on m6A modification of GSTO1. T98G cell phenotypes including proliferation and apoptosis were analyzed by cell counting kit 8, colony formation assay, and flow cytometry. The regulation of m6A methylation mediated by FTO was evaluated by methylated RNA immunoprecipitation, RNA immunoprecipitation, and dual-luciferase reporter assay. The results showed that FTO expression was downregulated in GBM. Overexpression of FTO inhibited cell proliferation and facilitated apoptosis in vitro. Additionally, GSTO1 expression was elevated in GBM, and knockdown of GSTO1 suppressed cell proliferation and promoted apoptosis and oxidative stress. Moreover, FTO inhibited m6A methylation of GSTO1 and reduced the stability of GSTO1. Overexpression of GSTO1 abrogated T98G cellular processes mediated by FTO. The in vivo experiments showed that FTO inhibited tumor growth by downregulating GSTO1 expression. In conclusion, FTO decelerates GBM progression by inducing apoptosis through suppressing m6A methylation of GSTO1., Competing Interests: Declarations. Ethics Approval and Consent to Participate: The Ethics Committee of Chun’an First People’s Hospital approved the implementation of this study.All patients provided written informed consent. All operating processes were performed in line with the principles of the Declaration of Helsinki. All animal experiments should comply with the ARRIVE guidelines. Consent for Publication: Not applicable. Competing Interests: The authors declare no competing interests., (© 2025. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: In recent years, the emphasis has shifted to understanding the role of N1-methyladenosine (m1A) in tumor progression as little is known about its regulatory effect on mRNA and its role in the metastasis of colorectal cancer (CRC)., Methods: We performed methylated RNA immunoprecipitation sequencing of tumor tissues and tumor-adjacent normal tissues from three patients with CRC to determine the m1A profile of mRNA in CRC. The expression of diaphanous-related formin 3 (DIAPH3) and its correlation with clinicopathological characteristics of CRC were evaluated using immunohistochemistry and online datasets. The role of DIAPH3 in the migration and invasion of CRC cells was evaluated using wound healing assay, Transwell assay and xenograft metastatic model. The downstream targets of DIAPH3 were screened using mass spectrometry. By co-transfecting DIAPH3 siRNA and a keratin 19 (KRT19) ectopic plasmid into CRC cells, the role of DIAPH3-KRT19 signaling axis was confirmed., Results: The mRNA level of DIAPH3 and its m1A modifications increased simultaneously in the CRC tissues. In addition, high DIAPH3 expression in CRC tissues is significantly associated with metastasis and progression to an advanced stage. After the knockdown of DIAPH3, the migration and invasion capabilities of CRC cells suffered a notable decline, which could be rescued by overexpressing KRT19. In addition, the proteasome inhibitor MG132 could block the degradation of KRT19 induced by DIAPH3 silencing., Conclusions: Our study reveals that DIAPH3 mRNA was modified in CRC cells by m1A methylation. Silencing DIAPH3 suppresses the migration and invasion of CRC cells, potentially through the proteasome-dependent degradation of downstream KRT19., Competing Interests: Declarations. Conflict of interest: The authors declare no competing interests. Ethics approval: Human ethics approval was obtained from the Human Research Ethics Committee of the Second Affiliated Hospital, School of Medicine, Zhejiang University. Informed consent was obtained from all the participants. Animal experiments were approved by the Animal Care and Use Committee of the Second Affiliated Hospital, School of Medicine, Zhejiang University. Consent to participate: All CRC patients provided informed consent for specimen collection before surgery., (© 2025. The Author(s).)

Understanding the heterogeneity of epigenetic modifications within single cells is pivotal for unraveling the nature of the complexity of gene expression and cellular function. In this study, we have developed a strategy based on multichrome encoding and "AND" Boolean logic recognition for multiplexed, spatially resolved imaging of single-cell RNA epigenetic modifications, termed as PRoximity Exchange-assisted Encoding of Multichrome (PREEM). Through the implementation of this strategy, we can now map the expression and nuclear distribution of multiple site-specific RNA N6-methyladenosine (m 6 A) modifications at the single-molecule resolution level in single-cells, and reveal the previously unknown heterogeneity. Notably, we demonstrate how these patterns change after treatment with various drugs. Moreover, cyclic imaging with tailed DNA self-assembly further suggest the scalability and adaptability of PREEM's design. As an innovative epigenetic modification imaging tool, PREEM not only broadens the horizons of single-cell epigenetics research, enabling joint analysis of multiple targets beyond the limitations of imaging channels, but also reveals cell-to-cell variability, thereby enhancing our capacity to explore cellular functions., Competing Interests: Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Emerging evidence has shown that the N 6 -methyladenosine (m 6 A) modification of RNA plays key roles in tumorigenesis and the progression of various cancers. However, the potential roles of the m 6 A modification of long noncoding RNAs (lncRNAs) in pancreatic cancer (PaCa) are still unknown. To analyze the prognostic value of m 6 A-related lncRNAs in PaCa, an m6A-related lncRNA signature was constructed as a risk model via Pearson's correlation and univariate Cox regression analyses in The Cancer Genome Atlas (TCGA) database. The tumor microenvironment (TME), tumor mutation burden, and drug sensitivity of PaCa were investigated by m 6 A-related lncRNA risk score analyses. We established an m 6 A-related risk prognostic model consisting of five lncRNAs, namely, LINC01091, AC096733.2, AC092171.5, AC015660.1, and AC005332.6, which not only revealed significant differences in immune cell infiltration associated with the TME between the high-risk and low-risk groups but also predicted the potential benefit of immunotherapy for patients with PaCa. Drugs such as WZ8040, selumetinib, and bortezomib were also identified as more effective for high-risk patients. Our results indicate that the m 6 A-related lncRNA risk model could be an independent prognostic indicator, which may provide valuable insights for identifying therapeutic approaches for PaCa., Competing Interests: Declarations. Ethics approval and consent to participate: All human specimens were collected in accordance with the protocol approved by the Ethics Committees of Zhongshan Hospital (Xiamen) of Fudan University (B2024-018) and all the study subjects provided written informed consent to participate. Consent for publication: Not applicable. Competing interests: The authors have no financial interest., (© 2025. The Author(s).)

Background: Bladder cancer (BC) is a malignant tumor. Methyltransferase-like 7B (MEETL7B) is a methyltransferase and its role in BC has not yet been revealed., Method: Stable METTL7B knockdown or overexpression were achieved by lentiviral transduction in SW780 and TCCSUP cell lines. Xenografts tumors were established via subcutaneous injection of stable transfectants in BALB/c mice., Results: A database search indicated that METTL7B was elevated in BC and it was validated in BC cell lines. METTL7B silencing suppressed cell proliferation and tumorigenesis in vitro and in vivo. Besides, METTL7B knockdown induced cell cycle arrest in G1 phase with a reduction in cyclin D1(CCND1), CDK4, and CDK6 levels and an elevation in CDKN2D levels in cells. Considering that ferroptosis is emerging as a therapeutic target for cancer, and the possible relationship between METTL7B and antioxidant enzymes. We, here, examined that ectopic METTL7B expression abolished ferroptosis markers in cells raised by Erastin treatment, including the production of lipid ROS, the increased cellular iron and MDA content, the decreased gene expression of ACSL3, FANCD2, and FADS2, as well as the mitochondrial injury observed by electron microscopy. Mechanically, ectopic METTL7B expression promoted m 6 A modification on ACSL3 mRNA. Gain of functional experiment exhibited that METTL7B inhibited Erastin-induced ferroptosis via ACSL3. Overexpressed PLAGL2 is identified as a possible independent predictor in BC and bioinformatics predicted the potential binding sites between PLAGL2 and METTL7B promoter region. Dual luciferase and chromatin immunoprecipitation analysis provided evidence that PLAGL2 directly binds to METTL7B promoter region., Conclusions: METTL7B is involved in BC development and progression. METTL7B may mediate m 6 A modification on ACSL3 mRNA to negatively regulate ferroptosis in BC cells, which provides a potential therapeutic target for BC via ferroptosis., Competing Interests: Declarations. Ethics approval and consent to participate: The animal experiment was approved by the Ethics Committee of China Medical University. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Hakai protein (CBLL1 gene) was identified as an E3 ubiquitin ligase of E-cadherin complex, inducing its ubiquitination and degradation, thus inducing epithelial-to-mesenchymal transition. Most of the knowledge about the protein was associated to its E3 ubiquitin ligase canonical role. However, important recent published research has highlighted the noncanonical role of Hakai, independent of its E3 ubiquitin ligase activity, underscoring its involvement in the N 6 -methyladenosine (m 6 A) writer complex and its impact on the methylation of RNA. The involvement of Hakai in this mRNA modification process has renewed the relevance of this protein as an important contributor in cancer. Moreover, Hakai potential as a cancer biomarker and its prognostic value in malignant disease also emphasize its untapped potential in precision medicine, which would also be discussed in detail in our review. The development of the first small-molecule inhibitor that targets its atypical substrate binding domain is a promising step that could eventually lead to patient benefit, and we would cover its discovery and ongoing efforts toward its use in clinic., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare that they have no competing interests., (© 2025. The Author(s).)

Microplastics are prevalent in aquatic ecosystems, impacting various forms of aquatic life, including fish. In this study, Rainbow trout (Oncorhynchus mykiss) were exposed to two concentrations of microplastics (0 and 500 μg/L) over a 14-day period, during which a comprehensive analysis was conducted to assess the liver accumulation of microplastics and their effects on oxidative stress, the liver response, and transcriptomics. Our findings indicated that microplastics significantly accumulated in the liver and activated the antioxidant system in fish by enhancing the activity of antioxidant enzymes. Histological lesions were also observed in the liver of the fish. Furthermore, microplastics induced alterations in the expression of hepatic N 6 -methyladenosine readers, specifically downregulating IGF2BP1 (encoding insulin like growth factor 2 mRNA binding protein 1) and upregulating YTHDF2 (encoding YTH N 6 -methyladenosine RNA binding protein F2), which in turn decreased mRNA stability and reduced the expression of C-myc and other regulatory factors involved in the cell cycle and proliferation. This sequence of events resulted in slowed cell proliferation, the induction of cell cycle arrest, and the promotion of cellular senescence. This study offers valuable insights into the toxicological mechanisms of microplastics and enhances our understanding of the threats that plastic pollution poses to freshwater organisms., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2025 Elsevier B.V. All rights reserved.)

Ovarian cancer (OC) is a heterogeneous cancer. In contrast to other tumor cells, which rely primarily on aerobic glycolysis (Warburg effect) as their energy source, oxidative phosphorylation (OXPHOS) is also one of its major metabolic modes. Piwi-interacting RNAs (piRNAs) play a regulatory function in various biological processes in tumor cells. However, the role and mechanisms of piRNAs in OC and mitochondrial OXPHOS remain to be elucidated. Here, we found that piR-26441 was aberrantly downregulated in OC, and its overexpression suppressed the malignant features of OC cells and tumor growth in a xenograft model. Moreover, overexpression of piR-26441 significantly reduced mitochondrial OXPHOS levels in OC cells. Furthermore, piR-26441 directly binds to and upregulates the expression of YTHDC1 in OC cells. piR-26441 also increased m6A levels, thereby interacting with YTHDC1 to destabilize the mRNA of TSFM. The resultant TSFM loss reduced mitochondrial complex I activity and mitochondrial OXPHOS, leading to mitochondrial dysfunction in OC cells, increased reactive oxygen species levels, and thus, DNA damage and apoptosis in OC cells, thereby inhibiting OC progression. Additionally, ago-piR-26441 suppressed tumor growth and mitochondrial metabolism in the patient-derived organoid model. Altogether, piR-26441 could inhibit OC cell growth via the YTHDC1/TSFM signaling axis, underscoring its significant importance in the context of OC, as well as offering potential as a therapeutic target., Competing Interests: Competing interests: The authors declare no competing interests. Ethics approval: The Ethics Committee of the Third Affiliated Hospital of Guangzhou Medical University (No: 2021-055) approved the use of human tissue in this study. All animal experiments were approved and conducted by Guangdong Medical Laboratory Animal Center (Approval No. B202208-8). We conformed with the Helsinki Declaration of 1975 (as revised in 2008) concerning Human and Animal Rights., (© 2025. The Author(s).)

Post-traumatic epilepsy (PTE) is a debilitating chronic outcome of traumatic brain injury (TBI). Although FTO has been reported as a possible intervention target of TBI, its precise roles in the PTE remain incompletely understood. Here we used mild or serious mice TBI model to probe the role and molecular mechanism of FTO in PTE. The results of electroencephalography showed that frequency of epilepsy in serious TBI model mice was more obvious. Using quantitative PCR (qPCR) and western blot analysis, we demonstrated that FTO and NR4A2 were downregulated, while m6A level of NR4A2 mRNA was upregulated in the hippocampus of serious TBI mice. Functionally, FTO overexpression was found to reduce epilepsy susceptibility, blood-brain barrier (BBB) disruption and neuronal damage in TBI mice, suggested a role for FTO in PTE. In addition, RNA-binding protein immunoprecipitation and dual-luciferase assay experiment showed that NR4A2 was a target of FTO, and FTO upregulated NR4A2 expression through m6A-YTHDF2 manner. Furthermore, the molecular and histological changes caused by FTO overexpression are markedly reversed by NR4A2 knockdown in TBI mice. Collectively, our results demonstrate that FTO alleviates epilepsy susceptibility and brain injury after TBI by mediating epigenetic up-regulation of NR4A2, which implicates it as a potential therapeutic target for PTE., Competing Interests: Declarations. Ethical approval: This study was approved by the Institutional Animal Committee of The Second Xiangya Hospital of Central South University (No. 20220659). Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Epitranscriptomic modifications, particularly N6-methyladenosine (m 6 A), are crucial regulators of gene expression, influencing processes such as RNA stability, splicing, and translation. Traditional computational methods for detecting m 6 A from Nanopore direct RNA sequencing (DRS) data are constrained by their reliance on experimentally validated labels, often resulting in the underestimation of modification sites. Here, we introduce pum6a, an innovative attention-based framework that integrates positive and unlabeled multi-instance learning (MIL) to address the challenges of incomplete labeling and missing read-level annotations. By combining electrical signal features with base alignment data and employing a weighted Noisy-OR probability mechanism, pum6a achieves enhanced sensitivity and accuracy in m 6 A detection, particularly in low-coverage loci. Pum6a outperforms existing methods in identifying m 6 A sites across various cell lines and species, without requiring extensive parameter tuning. We further apply pum6a to study the dynamic regulation of m 6 A demethylases in gastric cancer under hypoxia, revealing distinct roles for FTO and ALKBH5 in modulating m 6 A modifications and uncovering key insights into m 6 A -mediated transcript stability. Our findings highlight the potential of pum6a as a powerful tool for advancing the understanding of epitranscriptomic regulation in health and disease, paving the way for biotechnological and therapeutic applications., Competing Interests: Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

The diverse radiation types in medical treatments and the natural environment elicit complex biological effects on both cancerous and non-cancerous tissues. Radiation therapy (RT) induces oncological responses, from molecular to phenotypic alterations, while simultaneously exerting toxic effects on healthy tissue. N 6 -methyladenosine (m 6 A), a prevalent modification on coding and non-coding RNAs, is a key epigenetic mark established by a set of evolutionarily conserved enzymes. The interplay between m 6 A modification and radiobiology of cancerous and non-cancerous tissues merits in-depth investigation. This review summarizes the roles of m 6 A in the biological effects induced by ionizing radiation and ultraviolet (UV) radiation. It begins with an overview of m 6 A modification and its detection methods, followed by a detailed examination of how m 6 A dynamically regulates the sensitivity of cancerous tissues to RT, the injury response in non-cancerous tissues, and the toxicological effects of UV exposure. Notably, this review underscores the importance of novel regulatory mechanisms of m 6 A and their potential clinical applications in identifying epigenetically modulated radiation-associated biomarkers for cancer therapy and estimation of radiation dosages. In conclusion, enzyme-mediated m 6 A-modification triggers alterations in target gene expression by affecting the metabolism of the modified RNAs, thus modulating progression and radiosensitivity in cancerous tissues, as well as radiation effects on normal tissues. Several promising avenues for future research are further discussed. This review highlights the importance of m 6 A modification in the context of radiation biology. Targeting epi-transcriptomic molecules might potentially provide a novel strategy for enhancing the radiosensitivity of cancerous tissues and mitigating radiation-induced injury to normal tissues., Competing Interests: No potential conflicts of interest are disclosed., (Copyright © 2024 The Authors.)

The N6-methyladenosine (m6A) modification serves as an essential epigenetic regulator in eukaryotic cells, playing a significant role in tumorigenesis and cancer progression. However, the detailed biological functions and underlying mechanisms of m6A regulation in gastric cancer (GC) are poorly understood. Our research revealed that the m6A demethylase ALKBH5 was markedly downregulated in GC tissues, which was associated with poor patient prognosis. Functional studies demonstrated that suppressing ALKBH5 expression enhanced GC cell proliferation, migration, and invasion. Mechanistically, ALKBH5 removed m6A modifications from the 5' uncapped and polyadenylated transcripts (UPTs) of WRAP53. This demethylation decreased WRAP53 stability and translation efficiency. The lower level of WRAP53 disrupts the interaction between USP6 and RALBP1 protein, promoting RALBP1 degradation and thereby suppressing the PI3K/Akt/mTOR signaling cascade, ultimately attenuating the progression of GC. These findings highlight the pivotal role of ALKBH5-mediated m6A demethylation in inhibiting GC progression and the potential role of ALKBH5 as a promising biomarker and therapeutic target for GC intervention., Competing Interests: Declarations. Ethics approval and consent to participate: This study was approved by the Institutional Review Board of Sun Yat-Sen University Cancer Center. All animal experiments were approved by the Institutional Animal Care and Use Committee, Sun Yat-sen University Cancer Center (L102022024080C). Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Background and Aims: Ischemic heart disease (IHD) presents a significant global health challenge, with myocardial ischemia-reperfusion injury (MIRI) being a major pathophysiological contributor and lacking effective interventions. While aerobic exercise training (AET) enhances cardiovascular health, its protective mechanism in MIRI remains elusive. This study aims to elucidate the protective effect of AET in MIRI and its underlying mechanism., Methods: A mouse model of AET and MIRI was established to evaluate basic indices, cardiac ultrasound, and myocardial injury markers. Dot Blot, qRT-PCR, and Western blot were employed to assess m 6 A RNA methylation levels and related protein expression in myocardial tissue. In vitro, primary cardiomyocyte culture was utilized to mimic MIRI, evaluating cell viability, mitochondrial membrane potential, etc. Finally, myocardial tissues of MIRI mice were immunoprecipitated for m 6 A RNA methylation and sequenced to analyze related signaling pathways., Key Results: AET significantly improved cardiac function and mitigated myocardial injury and fibrosis. Moreover, AET protected myocardium from MIRI by reducing m 6 A RNA methylation levels and modulating METTL3 expression. In vitro experiments demonstrated that the decrease in m 6 A RNA methylation levels and METTL3 expression conferred resistance to hypoxia/reoxygenation-induced injury. Furthermore, sequencing results indicated elevated myocardial tissue m 6 A RNA methylation levels during MIRI, activation of the Nrf2-related signaling pathway, and AET-mediated regulation of the Nrf2/HO-1 signaling pathway, thereby attenuating MIRI through modulation of METTL3-related m 6 A methylation., Conclusion and Significance: AET attenuates MIRI by reducing the level of METTL3-related m 6 A RNA methylation in cardiomyocytes and activating the Nrf2/HO-1 antioxidant signaling pathway. This finding provides a novel insight and strategy for the prevention and treatment of IHD, holding significant clinical implications., Competing Interests: Declaration of competing interest No potential conflict of interest relevant to this article was reported., (Copyright © 2024. Published by Elsevier Inc.)

Organ fibrosis, a common consequence of chronic tissue injury, presents a significant health challenge. Recent research has revealed the regulatory role of N6-methyladenosine (m6A) RNA modification in fibrosis of various organs, including the lung, liver, kidney, and heart. In this comprehensive review, we summarize the latest findings on the mechanisms and functions of m6A modification in organ fibrosis. By highlighting the potential of m6A modification as a therapeutic target, our goal is to encourage further research in this emerging field and support advancements in the clinical treatment of organ fibrosis., (© The Author(s) 2025. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Aims: Regular exercise promotes the beiging and metabolic adaptations of white adipose tissue (WAT) through the cumulative transcriptional responses that occur after each exercise session. However, the effects of a single bout of acute exercise and the role of N 6 -methyladenosine (m 6 A) in these adaptations remain unclear. We aim to investigate this further., Materials and Methods: We constructed mouse models for chronic (8 weeks of running) and acute (single 1-hour run) exercise to study the effects on white adipose tissue (WAT) metabolism and beiging through metabolic phenotyping and transcriptome sequencing. Additionally, we explored the impact of acute exercise on WAT m 6 A modification and target genes, combining m 6 A regulators with cell models to elucidate the role of m 6 A in WAT exercise adaptation., Key Findings: Here, we reveal that upregulated m 6 A modification after acute exercise induces the formation of glycolytic beige fat (g-beige fat) in WAT. Mechanistically, the metabolite β-hydroxybutyrate (BHBA) secreted after acute exercise upregulates m 6 A modification in WAT. This enhances m 6 A-dependent translation of the histone acetyltransferase CREBBP, promoting the transcription of key beiging genes by increasing chromatin accessibility. Pharmacologically elevating circulating BHBA mimics the metabolic response induced by acute exercise, upregulating m 6 A modification and its downstream signals. Additionally, BHBA exhibits long-term effects, improving metabolic homeostasis in obesity by promoting thermogenesis in WAT., Significance: Our results reveal the role of metabolites in WAT metabolic adaptation through m 6 A-mediated chromatin accessibility after acute exercise, providing a novel therapeutic target for regulating WAT metabolism from a nutritional epigenetics perspective., Competing Interests: Declaration of competing interest The authors declare that they have no competing interest., (Copyright © 2024. Published by Elsevier Inc.)

Alterations in mitochondrial function are the linchpin in numerous disease states including in the development of chemotherapy-induced neuropathic pain (CIPN), a major dose-limiting toxicity of widely used chemotherapeutic cytotoxins. In CIPN, mitochondrial dysfunction is characterized by deficits in mitochondrial bioenergetics (e.g., decreased ATP production) that are thought to drive the degeneration of the peripheral nerve sensory axon terminal sensory arbors in the skin (the intraepidermal nerve fibers; IENFs) and induce abnormal spontaneous discharge in peripheral nerve sensory axons. Preserving mitochondrial function is anticipated to prevent CIPN. We have now discovered that the G-protein-coupled receptor, A 3 adenosine receptor subtype (A 3 AR), is expressed on the mitochondrial outer membrane. Ex vivo application of a highly selective A 3 AR agonist, MRS5980, to saphenous nerve microfilaments harvested from male oxaliplatin-treated rats reversed the loss in ATP production underscoring mitoprotective effects resulting from A 3 AR activation on mitochondria. Moreover, in vivo administration of A 3 AR agonists to rats during oxaliplatin treatment was associated with reduced IENF loss and a lower incidence of spontaneous discharge in peripheral afferent axons. These effects are accompanied by improved mitochondrial ATP production in primary afferent sensory axons and overall inhibition of the development of neuropathic pain. These data identify for the first time mitochondrial A 3 AR and indicate that activation of A 3 AR protects mitochondrial function in primary afferent sensory axons against chemotherapy-induced neurotoxicity. Repurposing A 3 AR agonists that are already in clinical trials as anticancer agents as adjunct to chemotherapeutics will address a major unmet medical need for which there are no FDA-approved drugs., (Copyright © 2024 the authors.)

Intrahepatic cholangiocarcinoma (ICC) is a primary invasive malignant tumor. This study was conducted to explore the role of methyltransferase-like 3 (METTL3)-mediated m6A modification in ICC cells and provide novel targets for ICC treatment. Levels of METTL3/YTH N6-methyladenosine RNA binding protein 2 (YTHDF2)/Nedd4 family interacting protein 1 (NDFIP1) in cells were determined. Cell viability, proliferation, invasion, and migration were evaluated. The enrichments of METTL3, YTHDF2, and m6A on NDFIP1 mRNA were analyzed. The mRNA stability was determined. Inhibition of YTHDF2 or NDFIP1 was combined with si-METTL3 to confirm the mechanism. The role of METTL3 in vivo was verified. METTL3 was overexpressed in ICC cells. METTL3 silencing suppressed ICC cell malignant behaviors, which were reversed by METTL3 overexpression. METTL3 increased m6A modification on NDFIP1 mRNA, facilitated YTHDF2 recognition of m6A, and promoted NDFIP1 mRNA degradation, thereby suppressing NDFIP1 expression. YTHDF2 inhibition increased NDFIP1 mRNA levels. NDFIP1 downregulation partially reversed the inhibitory effects of si-METTL3 on ICC cell behaviors, while NDFIP1 overexpression partially reversed the promotive effects of METTL3 on ICC cell behaviors. METTL3 downregulation suppressed ICC growth by increasing NDFIP1 expression. In conclusion, METTL3 aggravates ICC cell proliferation, invasion, and migration by promoting the degradation of NDFIP1 mRNA in a YTHDF2-dependent manner., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest to disclose., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: N6 methyladenosine (m6A) regulates the ferroptosis in different diseases. However, there is no report about the role of the m6A regulator in the ferroptosis process of septic cardiomyopathy (SCM). This study aims to find the potential m6A regulator that participates in the ferroptosis process of SCM., Methods: Genes related to m6A were identified through bioinformatics analysis in GSE142615. Then, the expression of Rrp8, Trmt6, Trmt61a, Ythdf1, and ZC3H13 was detected in lipopolysaccharide (LPS)-treated HL-1 cells using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). After overexpression or interference with ZC3H13, Cell Counting Kit-8 measured cell proliferation, flow cytometry detected apoptosis and reactive oxygen species (ROS) accumulation was observed. Then, we identified the potential downstream genes of ZC3H13 through further bioinformatics analysis followed by qRT-PCR and western blotting validation., Results: There were five differentially expressed genes related to m6A, including Rrp8, Trmt6, Trmt61a, Ythdf1, and ZC3H13. The expression of Rrp8, Trmt6, Trmt61a, Ythdf1, and ZC3H13 mRNA was significantly up-regulated in the LPS-treated HL-1 cells, with ZC3H13 having the highest expression. Furthermore, overexpression of ZC3H13 inhibited the proliferation of HL-1 cells and promoted apoptosis and ROS accumulation. While, interfering with ZC3H13 promoted the proliferation of LPS-treated HL-1 cells, and reduced apoptosis and ROS accumulation. Additionally, si-ZC3H13 promoted the expression of Pnn, GPX4, and SLC7A11; while inhibiting the expression of Rbm25 and Caspase 3., Conclusions: In a word, the silence of ZC3H13 increased the proliferation and ferroptosis-related protein expression, decreased apoptosis and ROS accumulation, as well as maybe by regulating Pnn and Rbm25 expression., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Acute lung injury (ALI) is a severe condition with multifaceted causes, including inflammation and oxidative stress. This research investigates the influence of m6A (N6-methyladenosine) modification on GBP4, a protein pivotal for macrophage polarization, a critical immune response in ALI., Methods: Utilizing a mouse model to induce ALI, the study analyzed GBP4 expression in alveolar macrophages. By overexpressing or knocking down GBP4, the study assessed its impact on M1 macrophage polarization. The role of YTHDF1 was also explored through knockdown experiments to determine its effect on GBP4 expression and macrophage polarization., Results: Increased GBP4 expression was noted in ALI model mice, promoting M1 macrophage polarization. YTHDF1 was found to enhance GBP4 expression by recognizing m6A sites on its mRNA, which was linked to reduced inflammation in MLE-12 cells upon YTHDF1 knockdown., Conclusion: The study emphasizes the crucial roles of GBP4 and YTHDF1 in ALI development and immune response regulation. It suggests m6A modification as a potential therapeutic target, contributing to the understanding of ALI's molecular mechanisms and guiding future treatment strategies., Competing Interests: Declarations. Ethics approval: Mice used in this study were housed with free access to food and water under protocols approved by the Zhengzhou University Institutional Animal Care and Use Committee (2020-KY-462). Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Background: Recent studies indicate that N6-methyladenosine (m 6 A) RNA modification may regulate ferroptosis in cancer cells, while its molecular mechanisms require further investigation., Methods: Liquid Chromatography-Tandem Mass Spectrometry (HPLC/MS/MS) was used to detect changes in m 6 A levels in cells. Transmission electron microscopy and flow cytometry were used to detect mitochondrial reactive oxygen species (ROS). RNA sequencing (RNA-seq) was employed to analyze the factors regulating ferroptosis. Chromatin immunoprecipitation (ChIP) was used to assess the binding of regulatory factors to the SLC7A11 promoter, and a Dual-Luciferase reporter assay measured promoter activity of SLC7A11. The dm 6 ACRISPR system was utilized for the demethylation of specific transcripts. The Cancer Genome Atlas Program (TCGA) database and immunohistochemistry validated the role of the METTL3/SLC7A11 axis in cancer progression., Results: The m 6 A methyltransferase METTL3 was upregulated during cancer cell ferroptosis and facilitated erastin-induced ferroptosis by enhancing mitochondrial ROS. Mechanistic studies showed that METTL3 negatively regulated the transcription and promoter activity of SLC7A11. Specifically, METTL3 induced H3K27 trimethylation of the SLC7A11 promoter by suppressing the mRNA stability of H3K27 demethylases KDM6B. Furthermore, METTL3 suppressed the expression of GATA3, which regulated SLC7A11 transcription by binding to the putative site at - 597 to - 590 of the SLC7A11 promoter. METTL3 decreased the precursor mRNA stability of GATA3 through m 6 A/YTHDF2-dependent recruitment of the 3'-5' exoribonuclease Dis3L2. Targeted demethylation of KDM6B and GATA3 m 6 A using the dm 6 ACRISPR system significantly increased the expression of SLC7A11. Moreover, the transcription factor YY1 was responsible for erastin-induced upregulation of METTL3 by binding to its promoter-proximal site. In vivo and clinical data supported the positive roles of the METTL3/SLC7A11 axis in tumor growth and progression., Conclusions: METTL3 regulated the transcription of SLC7A11 through GATA3 and KDM6B to modulate ferroptosis in an m 6 A-dependent manner. This study provides a novel potential strategy and experimental support for the future treatment of cancer., Competing Interests: Declarations. Ethics approval and consent to participate: All animal experiments complied with the Zhongshan School of Medicine Policy on the Care and Use of Laboratory Animals. Consent for publication: Not applicable. Competing interests: The authors declare that they have no competing interests., (© 2025. The Author(s).)

Ethnopharmacological Relevance: Gan-Jiang-Ling-Zhu (GJLZ) decoction, a classical Chinese herbal prescription, can be applied for the treatment of metabolic diseases including liver steatosis. Although GJLZ decoction has been widely applied clinically for thousands of years, the mechanism of GJLZ decoction behind treatment of nonalcoholic steatohepatitis (NASH) remains relatively unelucidated., Aim of the Study: To elucidate the efficacy of GJLZ decoction in the treatment of NASH and to investigate its underlying mechanisms from an epigenetic perspective., Materials and Methods: The quality control of chemical components in GJLZ decoction was conducted. C57BL/6J mice with NASH were induced by feeding them a choline-deficient-high-fat-diet (CDHFD), along with GJLZ decoction intervention for 4 weeks. Then NASH phenotypes including histological steatosis, inflammation, hepatic apoptosis, fibrosis, serum liver enzyme and lipid level were measured. N6-methyladenosine (m 6 A) and transcriptome sequencing were performed. Levels and functions of methyltransferases and different genes were performed by quantitative polymerase chain reaction, immunofluorescence, gene knockdown, oil red O staining and western blotting., Results: GJLZ decoction significantly reduced liver weight, liver index and improved hepatic steatosis, and inflammation, as well as inhibited hepatic apoptosis and fibrosis. Moreover, GJLZ decoction significantly reduced the levels of lactate dehydrogenase, aminotransferase, triglyceride, aspartate aminotransferase, and inhibited levels of interleukin 6 and tumor necrosis factor α. Transcriptome and m 6 A sequencing revealed the landscape of transcriptome and m 6 A modification influenced by NASH and the following GJLZ decoction intervention. Eleven differential genes were identified, and GJLZ markedly promoted m 6 A level of UDP glucuronosyltransferase family 2 member A3 (Ugt2a3), to promote its expression. Additionally, GJLZ significantly promoted methyltransferase 14 (METTL14) expression, whereas METTL14 knockdown aggravated hepatocellular steatosis. Finally, METTL14 knockdown significantly reduced the level of Ugt2a3 by promoting its degradation, whereas, Ugt2a3 overexpression could markedly inhibit hepatocellular steatosis., Conclusions: GJLZ decoction demonstrates potential in alleviating CDHFD-induced NASH by modulating the METTL14-m 6 A-Ugt2a3 axis, offering a novel therapeutic approach for NASH treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

N6-methyladenosine (m6A) modification is a key methylation modification involved in reproductive processes. Myostatin gene editing (MT) in cattle is known to enhance muscle mass and productivity. However, the changes in m6A modification in MT bull sperm remain poorly understood. In the MT and wild-type (WT) groups, we identified 25,542 and 22,253 m6A peaks, respectively, mainly concentrated in the coding sequence (CDS) and 3' untranslated region (UTR) of genes. The MT group showed an increase in gene transcription, but there was no significant difference in the overall m6A peaks pattern. There was also no significant difference in m6A motif and chromosome distribution between MT and WT groups. Most genes had less m6A modification sites. A total of 1120 m6A peaks were significantly different, corresponding to 1053 differentially m6A-methylated genes (DMMGs). These DMMGs are mainly associated with G protein-coupled receptor signaling pathways and the overall composition of the cell membrane. Furthermore, an MCL clustering analysis of 111 differentially m6A-methylated and expressed genes identified seven key genes ( RHOA , DAAM1 , EXOC4 , GNA12 , PRICKLE1 , SCN1A, and STXBP5L ), with the cytoskeleton and migration-related gene, RHOA , being the most important gene located at the center of the gene network. However, the analysis of sperm morphology and motility indicated no significant changes in semen volume, sperm count, sperm viability, plasma membrane integrity, acrosome membrane integrity, or mitochondrial membrane integrity. This study provides a map of m6A methylation in spermatozoa from MT and WT bulls, identifies key differential m6A genes that are affected by the myostatin gene but do not affect sperm morphology and viability in MT bulls, and provides a theoretical basis for the breeding quality of MT bulls.

Utilizing base-conversion (BC) techniques, single-base resolution profiling of RNA and DNA modifications has significantly advanced. BC strategies range from one-way conversions (e.g. cytosine-to-thymine for 5-methylcytosine, adenine-to-guanine for N6-methyladenosine), to multi-way conversions (e.g. adenine to cytosine/guanine/thymine for N1-methyladenosine) and deletion-induced conversions (e.g. pseudouridine-to-deletion). Existing sequence aligners struggle with these diverse conversions, often leading to misaligning or inefficiency. We introduce BASAL (BAse-conversion Sequencing ALigner), which leverages bit-masking technology to accurately calculate mismatch penalties and supports all BC strategies. BASAL outperforms state-of-the-art tools in both mapping accuracy and efficiency. Through simulated and real data testing, along with experimental validation, we demonstrate that BASAL excels at identifying reliable modification sites. Moreover, BASAL enhances single-cell m6A analysis, revealing cell subpopulations and a cell evolutionary direction that align with biological functions, which other aligners fall short. BASAL's versatility establishes it as a universal aligner for RNA and DNA modification sequencing, facilitating groundbreaking discoveries in epigenomics and epitranscriptomics., (© The Author(s) 2024. Published by Oxford University Press on behalf of Nucleic Acids Research.)

Background: Osteoarthritis (OA) is a chronic degenerative joint disease characterized by the breakdown of cartilage and extracellular matrix (ECM). The degradation of ECM in chondrocytes plays a crucial role in OA pathogenesis, but the underlying molecular mechanisms remain largely unclear., Methods: A sodium monoiodoacetate (MIA) mouse model was used to mimic OA. ECM integrity was accessed by Hematoxylin and Eosin (H&E) staining, Safranin O/fast green staining, and microcomputerized tomography. Enzyme-linked immunosorbent assay measured circulating proinflammatory cytokines. Reverse transcription-quantitative polymerase chain reaction and western blotting analyzed mRNA and protein expression levels. RNA and chromatin immunoprecipitation evaluated RNA-protein and DNA-protein interactions., Results: MIA mice showed significant upregulation of the RNA m 6 A demethylase ALKBH5 (alkylated DNA repair protein AlkB homolog 5), the transcription factor Runx2 (runt-related transcription factor 2), and matrix-degrading enzymes Mmps (matrix metallopeptidase) and Adamts(s) (a disintegrin and metalloproteinase with thrombospondin motifs). In vitro, proinflammatory cytokines induced these proteins in chondrocytes. Mechanically, Alkbh5 cooperated with Ythdf1 (YTH N6-methyladenosine RNA binding protein 1) in the inflammatory microenvironment to regulate the expression and stability of RUNX2 mRNA. Runx2, in turn, activated the expression of MMPs and ADAMTSs, promoting ECM degradation in chondrocytes, thereby contributing to OA progression. Notably, inhibition of Alkbh5 and Runx2 in MIA-treated mice significantly alleviated the pathological progression of OA., Conclusion: Our results reveal a novel mechanism of OA pathogenesis and suggest that targeting Alkbh5 and Runx2 may represent a new therapeutic strategy for OA treatment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Infectious spleen and kidney necrosis virus (ISKNV) is a highly virulent and rapidly transmissible fish virus that poses threats to the aquaculture of a wide variety of freshwater and marine fish. N6-methyladenosine (m 6 A), recognized as a common epigenetic modification of RNA, plays an important regulatory role during viral infection. However, the impact of m 6 A RNA methylation on the pathogenicity of ISKNV remains unexplored. Here, methylated RNA immunoprecipitation sequencing (MeRIP-seq) coupled with RNA sequencing (RNA-seq) was used to systematically detect variations in m 6 A methylation and gene expression between ISKNV-infected and noninfected MFF-1 cells, followed by functional enrichment and co-expression joint analysis. The findings revealed that the m 6 A methylation peaks were located mainly in coding sequences (CDSs), with more than 90% of the transcripts containing 1-5 m 6 A peaks. Through MeRIP-seq, 4361 differentially m 6 A-methylated mRNAs were identified. Gene enrichment analysis revealed that m 6 A-related genes were enriched in biological processes and pathways such as gene expression, cellular structure, immune responses, and cell death. Co-expression analysis revealed that the genes differentially expressed at both the mRNA and m 6 A modification levels were enriched in pathways such as the hippo, ErbB, and JAK-STAT pathways. The m 6 A modification at the genome-wide transcription level of ISKNV was subsequently shown to be pronounced in several pivotal genes, such as putative vascular endothelial growth factor, ribonucleotide reductase small subunit, and E3 ubiquitin ligase. This study comprehensively describes the m 6 A expression profile in ISKNV- and ISKNV-infected MFF-1 cells, providing a basis for investigating the role of m 6 A modification during ISKNV infection., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

N 6 -methyladenosine (m 6 A) is among the most abundant mRNA modifications, yet its cell-type-specific regulatory roles remain unclear. Here we show that m 6 A methyltransferase-like 14 (METTL14) differentially regulates transcriptome in brown versus white adipose tissue (BAT and WAT), leading to divergent metabolic outcomes. In humans and mice with insulin resistance, METTL14 expression differs significantly from BAT and WAT in the context of its correlation with insulin sensitivity. Mettl14-knockout in BAT promotes prostaglandin secretion, improving systemic insulin sensitivity. Conversely, Mettl14-knockout in WAT triggers adipocyte apoptosis and systemic insulin resistance. m 6 A-seq and RNA-seq integration revealed upregulated prostaglandin biosynthesis pathways in BAT and apoptotic pathways in WAT with Mettl14 deficiency. Stable METTL14-knockout hBAs/hWAs show METTL14-mediated m 6 A promotes mRNA decay of PTGES2 and CBR1 in hBAs and TRAIL and TNFR1 in hWAs. These data shed light on the ability of m 6 A to impact metabolism in a cell-type-specific manner with implications for influencing the pathophysiology of metabolic diseases., Competing Interests: Competing interests: R.N.K. is on the scientific advisory board of Novo Nordisk, Biomea and REDD. C.H. is a scientific founder and a member of the scientific advisory board of Accent Therapeutics. M.B. received honoraria as a consultant and speaker from Amgen, AstraZeneca, Bayer, Boehringer Ingelheim, Daiichi-Sankyo, Lilly, Novo Nordisk, Novartis, and Sanofi. The remaining authors have no conflicts of interest., (© 2025. The Author(s).)

Over 170 types of chemical modifications have been identified in cellular RNAs across the three domains of life. Modified RNA is eventually degraded to constituent nucleosides, and in mammals, modified nucleosides are released into the extracellular space. By contrast, the fate of modified nucleosides in bacteria remains unknown. In this study, we performed liquid chromatography-mass spectroscopy (LC-MS) analysis of modified nucleosides from the RNA of 23 pathogenic bacteria, revealing 2-methyladenosine (m 2 A) as a common bacteria-specific modified nucleoside detected in all bacterial RNAs. Under normal culture conditions, bacteria did not actively release most modified nucleoside species, but robustly released nucleosides, including m 2 A, following addition of antibiotics or immune cells. These results indicate that m 2 A is released following bacterial lysis. Intraperitoneal injection of mice with m 2 A increased detectable levels of m 2 A in the urine, indicating that mammals can effectively excrete m 2 A. Additionally, mice infected with wild-type E. coli showed higher levels of m 2 A in their urine than mice infected by m 2 A-deficient rlmN KO E. coli . This suggests that m 2 A from the infected bacteria is excreted in the urine. Lastly, clinical studies using urine samples from febrile patients revealed significantly elevated levels of m 2 A during bacterial infections, and these values did not correlate with inflammation severity markers, such as white blood count (WBC) and C-reactive protein (CRP). This study reports the mammalian metabolism of modified nucleosides derived from bacterial RNA, and the elevation of urinary m 2 A in patients with bacterial infections., Importance: This study reveals the differences in the fate and release of modified nucleosides in bacteria and mammals. Additionally, our study highlights that external bacteria-damaging factors, such as antibiotics and phagocytosis by host immune cells, promote the release of bacteria-specific modified nucleosides. Furthermore, we found that m 2 A was elevated in the urine from animal models of bacterial infection and the urine of patients with bacterial infections. Collectively, this work spans basic biology and clinical science, offering valuable insights into the fate of modified nucleosides in bacterial systems and their relevance to infectious diseases., Competing Interests: The authors declare no conflict of interest.

As the most abundant eukaryotic mRNA modification, N 6 -methyladenosine (m 6 A) plays a crucial role in regulating multiple biological processes. This methylation is regulated by methyltransferases and demethylases. However, the regulatory role and mode of action of m 6 A demethylases in fungi remain poorly understood. In this study, we demonstrate that CpALKBH is a demethylase in Cryphonectria parasitica that removes m 6 A modification from single-stranded RNA in vitro . The deletion of CpALKBH resulted in a significant increase in the m 6 A methylation levels, along with decreases in the growth rate, sporulation, and virulence in C. parasitica . Additionally, CpZap1-a transcription factor-was identified as a downstream target of CpALKBH demethylase based on RNA sequencing analysis. We confirmed that CpALKBH demethylase regulates CpZap1 mRNA stability in an m 6 A-dependent manner. Furthermore, through MazF assay, we found that methylation of CpZap1 at position 1935A is regulated by both CpALKBH demethylase and CpMTA1 methyltransferase. CpZap1 significantly influences the fungal phenotype and virulence, thereby restoring the abnormal phenotype observed in ∆ CpALKBH mutants. Collectively, our findings highlight the essential role of CpALKBH as an m 6 A demethylase in the development and virulence of C. parasitica , while also elucidating the molecular mechanisms through which m 6 A modification impacts CpZap1 mRNA stability., Importance: N 6 -methyladenosine (m 6 A) is the most abundant eukaryotic mRNA modification and is involved in various biological processes. Methyltransferases and demethylases regulate the m 6 A modification, but the regulatory role of m 6 A demethylases in fungi remains poorly understood. Here, we demonstrated that CpALKBH functions as a demethylase in Cryphonectria parasitica . The deletion of CpALKBH leads to a significant increase in m 6 A levels and a reduction in fungal growth, sporulation, and virulence. We identified CpZap1 as a downstream target of CpALKBH, with CpALKBH regulating CpZap1 mRNA stability in an m 6 A-dependent manner. Additionally, our findings indicate that methylation at position 1935A of CpZap1 is regulated by both the CpALKBH demethylase and the CpMTA1 methyltransferase. Given its critical role in fungal development and virulence, overexpression of CpZap1 can rescue abnormal phenotypes of ∆ CpALKBH mutant. Overall, these findings contribute to improving our understanding of the role of m 6 A demethylase in fungi., Competing Interests: The authors declare no conflict of interest.

The most effective method for mapping N6-methyladenosine (m 6 A) is m 6 A RNA immunoprecipitation sequencing (MeRIP-seq). The quality of MeRIP-seq relies on various factors, with the anti-m 6 A antibody being a crucial determinant. However, comprehensive research on anti-m 6 A antibody selection and optimal concentrations for different tissues has been limited. In this study, we optimized the concentration of five different anti-m 6 A antibodies across various tissues. Our findings demonstrated that 5 µg of Millipore antibodies (ABE572 and MABE1006) performed well, starting from 15 µg total RNA from the liver, while 1.25 µg of Cell Signaling Technology antibodies (CST) (#56593) was suitable for low-input total RNA. In summary, we provide a significant guideline for anti-m 6 A antibody selection in MeRIP sequencing for different tissues, especially in the context of low-input RNA., Competing Interests: Declarations. Competing interests: The authors declare no competing interests. Ethics approval and consent to participate: The study was approved by the Medical Ethical Committee of Suzhou Municipal Hospital with the number of 2019-003 and all participants provided written informed consent. Consent for publication: Not applicable., (© 2025. The Author(s).)

Objective: Arthritis is a class of diseases, characterized by joint and surrounding inflammation, accompanied by joint swelling, pain, dysfunction. According to different factors, arthritis can be divided into osteoarthritis, rheumatoid arthritis, ankylosing spondylitis and so on. N6-methyladenosine (m6A) is the most common internal modification of eukaryotic mRNA and is involved in splicing, stabilization, output and degradation of RNA metabolism. This review systematically summarized current insights into the mechanism of m6A in arthritis., Methods: The studies related to the involvement of m6A in the pathogenesis of arthritis reported in PubMed, Google scholar, and other open source literatures were investigated to evaluate the important roles of m6A in arhtritis, and the clinical relevances., Results and Conclusions: M6A methylation regulators play the roles of writers, erasers, and readers, are crucial for regulating gene expression, and play important roles in many biological processes such as virus replication and cell differentiation. In addition, more and more studies have shown that m6A is closely related to the development of arthritis. As a new therapeutic target for arthritis, m6A has a wide influence on the pathological mechanism of arthritis. However, further research is needed to determine how m6A affects arthritis pathology and its use in target therapy and diagnosis., Competing Interests: Declarations. Competing interests: The authors declare no competing interests. Ethics declarations: Not applicable., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Although glycosidic bonds in purines typically involve the N9 position, the chemical synthesis of adenosine produces N7-ribofuranosyladenine (7A) as a kinetically favorable ribosylation product. Similarly, in the synthesis of LNA-adenosine (AL), a minor product, N7-LNA-adenosine (7AL), is observed. While extensive research has focused on investigating the properties of N9-regioisomers of adenosine, 7A has been largely overlooked and considered as a side-product. In this study, we conducted comprehensive experimental and computational investigations to elucidate the structural and thermodynamic properties of 7A and 7AL. Our results reveal that 7A and 7AL primarily enhance the thermodynamic stability of 1 × 1 mismatches when paired with purines but decrease stability when paired with pyrimidines. Utilizing nuclear magnetic resonance and computational techniques, we discovered that 1 × 1 7A:A and 7AL:A prefer anti-anti conformations, while 1 × 1 7A:G and 7AL:G prefer syn-anti orientations, both forming two hydrogen bond states, resulting in enhanced duplex stabilities. Altogether, these findings underscore the unique properties of 7A and 7AL when incorporated in RNA, which could advance structure-based RNA studies and potentially be utilized to modulate binding affinity, selectivity and biostability of RNA molecules., (© The Author(s) 2024. Published by Oxford University Press on behalf of Nucleic Acids Research.)

Circular RNAs (circRNAs) are covalently closed RNAs that are present in all eukaryotes tested. Recent RNA sequencing (RNA-seq) analyses indicate that although generally less abundant than messenger RNAs (mRNAs), over 1.8 million circRNA isoforms exist in humans, much more than the number of currently known mRNA isoforms. Most circRNAs are generated through backsplicing that depends on pre-mRNA structures, which are influenced by intronic elements, for example, primate-specific Alu elements, leading to species-specific circRNAs. CircRNAs are mostly cytosolic, stable and some were shown to influence cells by sequestering miRNAs and RNA-binding proteins. We review the increasing evidence that circRNAs are translated into proteins using several cap-independent translational mechanisms, that include internal ribosomal entry sites, N6-methyladenosine RNA modification, adenosine to inosine RNA editing and interaction with the eIF4A3 component of the exon junction complex. CircRNAs are translated under conditions that favor cap-independent translation, notably in cancer and generate proteins that are shorter than mRNA-encoded proteins, which can acquire new functions relevant in diseases., (© The Author(s) 2024. Published by Oxford University Press on behalf of Nucleic Acids Research.)

A-to-I RNA editing is the most common non-transient epitranscriptome modification. It plays several roles in human physiology and has been linked to several disorders. Large-scale deep transcriptome sequencing has fostered the characterization of A-to-I editing at the single nucleotide level and the development of dedicated computational resources. REDIportal is a unique and specialized database collecting ∼16 million of putative A-to-I editing sites designed to face the current challenges of epitranscriptomics. Its running version has been enriched with sites from the TCGA project (using data from 31 studies). REDIportal provides an accurate, sustainable and accessible tool enriched with interconnections with widespread ELIXIR core resources such as Ensembl, RNAcentral, UniProt and PRIDE. Additionally, REDIportal now includes information regarding RNA editing in putative double-stranded RNAs, relevant for the immune-related roles of editing, as well as an extended catalog of recoding events. Finally, we report a reliability score per site calculated using a deep learning model trained using a huge collection of positive and negative instances. REDIportal is available at http://srv00.recas.ba.infn.it/atlas/., (© The Author(s) 2024. Published by Oxford University Press on behalf of Nucleic Acids Research.)