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Summary: Eukaryotic translation initiation factors (eIFs) are the primary targets for overcoming RNA virus resistance in plants. In a previous study, we mapped a BjeIF2Bβ from Brassica juncea representing a new class of plant virus resistance genes associated with resistance to Turnip mosaic virus (TuMV). However, the mechanism underlying eIF2Bβ‐mediated virus resistance remains unclear. In this study, we discovered that the natural variation of BjeIF2Bβ in the allopolyploid B. juncea was inherited from one of its ancestors, B. rapa. By editing of eIF2Bβ, we were able to confer resistance to TuMV in B. juncea and in its sister species of B. napus. Additionally, we identified an N6‐methyladenosine (m6A) demethylation factor, BjALKBH9B, for interaction with BjeIF2Bβ, where BjALKBH9B co‐localized with both BjeIF2Bβ and TuMV. Furthermore, BjeIF2Bβ recruits BjALKBH9B to modify the m6A status of TuMV viral coat protein RNA, which lacks the ALKB homologue in its genomic RNA, thereby affecting viral infection. Our findings have applications for improving virus resistance in the Brassicaceae family through natural variation or genome editing of the eIF2Bβ. Moreover, we uncovered a non‐canonical translational control of viral mRNA in the host plant. [ABSTRACT FROM AUTHOR]

Purpose: To highlight the trends and frontiers of RNA methylation in cancer over the past 10 years. Methods: Research publications on RNA methylation in cancer were retrieved from the Web of Science Core Collection database. VOSviewer, CiteSpace, and Bibliometrix were used to conduct bibliometric and visualization analysis of countries, institutions, authors, journals, and keywords relevant to this field. Results: From 2014 to 2023, research on RNA methylation in cancer has developed rapidly, with an overall increase in the number of publications and citations. China (4320 papers, 115056citations), Sun Yat Sen University (274 papers, 15698 citations), and Zhang, Wei (48 papers, 893 citations) are respectively the countries, institutions, and authors with the highest number of published papers and citations. Frontiers in Oncology (182 papers, 2524 citations) and Molecular Cancer (69 papers, 9224 citations) are the journals with the highest number of published papers and citations in this field, respectively. Cooccurrence analysis of keywords indicates that the research topics can be divided into five clusters: Cluster one: The Role of RNA Methylation in Tumor Heterogeneity, Therapeutic Response, and Prognosis; Cluster two: The Role of Noncoding RNA in RNA Methylation and Tumors; Cluster three: Potential Therapeutic Targets of RNA Methylation in Tumors; Cluster four: The role of RNA methylation in tumor progression and metastasis: A case study of hepatocellular carcinoma and gastric cancer; Cluster five: Regulation mechanisms of m6A methylation in leukemia cell differentiation and tumorigenesis. Conclusion: This is the first comprehensive study using bibliometrics to analyze the trends and frontiers of RNA methylation in cancer over the past 10 years, pointing out promising research directions for the future and providing valuable references for researchers in this field. [ABSTRACT FROM AUTHOR]

N6‐methyladenosine (m6A) is the most prevalent internal modification of mRNA and plays an important role in regulating plant growth. However, there is still a lack of effective tools to precisely modify m6A sites of individual transcripts in plants. Here, programmable m6A editing tools are developed by combining CRISPR/dCas13(Rx) with the methyltransferase GhMTA (Targeted RNA Methylation Editor, TME) or the demethyltransferase GhALKBH10 (Targeted RNA Demethylation Editor, TDE). These editors enable efficient deposition or removal of m6A modifications at targeted sites of endo‐transcripts GhECA1 and GhDi19 within a broad editing window ranging from 0 to 46 nt. TDE editor significantly decreases m6A levels by 24%–76%, while the TME editor increases m6A enrichment, ranging from 1.37‐ to 2.51‐fold. Furthermore, installation and removal of m6A modifications play opposing roles in regulating GhECA1 and GhDi19 mRNA transcripts, which may be attributed to the fact that their m6A sites are located in different regions of the genes. Most importantly, targeting the GhDi19 transcript with TME editor plants results in a significant increase in root length and enhanced drought resistance. Collectively, these m6A editors can be applied to study the function of specific m6A modifications and have the potential for future applications in crop improvement. [ABSTRACT FROM AUTHOR]

As the role of RNA modification in gene expression regulation and human diseases, the "epitranscriptome" has been shown to be an important player in regulating many physiological and pathological processes. Meanwhile, the phenomenon of cancer drug resistance is becoming more and more frequent, especially in the case of cancer chemotherapy resistance. In recent years, research on relationship between post-transcriptional modification and cancer including drug resistance has become a hot topic, especially the methylation of the sixth nitrogen site of RNA adenosine-m6A (N6-methyladenosine). m6A modification is the most common post-transcriptional modification of eukaryotic mRNA, accounting for 80% of RNA methylation modifications. At the same time, several other modifications of RNA, such as N1-methyladenosine (m1A), 5-methylcytosine (m5C), 3-methylcytosine (m3C), pseudouridine (Ψ) and N7-methylguanosine (m7G) have also been demonstrated to be involved in cancer and drug resistance. This review mainly discusses the research progress of RNA modifications in the field of cancer and drug resistance and targeting of m6A regulators by small molecule modulators, providing reference for future study and development of combination therapy to reverse cancer drug resistance. [ABSTRACT FROM AUTHOR]

Summary Light is essential not only for photosynthesis but also for the regulation of various physiological and developmental processes in plants. While the mechanisms by which light regulates transcription and protein stability are well established, the effects of light on RNA methylation and their subsequent impact on plant growth and development are less understood. Upon exposure to blue light, the photoreceptor cryptochromes form nuclear speckles or nuclear bodies, termed CRY photobodies. The CRY2 photobodies undergo light‐induced homo‐oligomerization and liquid–liquid phase separation (LLPS), which are crucial for their physiological activity. Recent studies have proposed that blue light‐induced CRY2 LLPS increases the local concentration or directly enhances the biochemical activities of RNA N6‐methyladenosine (m6A) methyltransferases, thus, to regulate circadian clock and maintain Chl homeostasis through processes of RNA decay or translation. This review aimed to elucidate the functions of CRY2 and LLPS in RNA methylation, focusing on the light‐controlled reversible phase transitions regulon and the outstanding questions that remain in RNA methylation. [ABSTRACT FROM AUTHOR]

Prostate cancer (PCa) is one of the most prevalent and deadly cancers among men, particularly affecting men of African descent and contributing significantly to cancer-related morbidity and mortality worldwide. The disease varies widely, from slow-developing forms to highly aggressive or potentially fatal variants. Accurate risk stratification is crucial for making therapeutic decisions and designing adequate clinical trials. This review assesses a broad spectrum of diagnostic and prognostic biomarkers, many of which are incorporated into clinical guidelines, including the Prostate Health Index (PHI), 4Kscore, STHLM3, PCA3, SelectMDx, ExoDx Prostate Intelliscore (EPI), and MiPS. It also highlights emerging biomarkers with preclinical support, such as urinary non-coding RNAs and DNA methylation patterns. Additionally, the review explores the role of tumor-associated microbiota in PCa, offering new insights into its potential contributions to disease understanding. By examining the latest advancements in PCa biomarkers, this review enhances understanding their roles in disease management. [ABSTRACT FROM AUTHOR]

Effective prevention and treatment options for bone cancer-related pain (BCP) are lacking. In recent years, numerous studies have investigated the association between m6A epigenetic modifications and pain, revealing their significant role in pain initiation and maintenance. This study aimed to provide theoretical support for the treatment of BCP and to identify target drugs for future development. Specifically, we investigated the involvement of fat mass and obesity-related protein (FTO) in rat models of BCP by administering varying doses (1/5/10 mg/kg) of the FTO inhibitor meclofenamic acid (MA) and assessing changes in mechanical sensitivity through domain analysis, gait analysis, and open-field experiments. After successfully establishing the BCP model, we verified it by performing mechanical sensitivity assessments. We observed significantly increased expression levels of the demethylase FTO within the spinal dorsal horn accompanied by decreased m6A methylation levels in the model. Compared with untreated BCP rats, remarkably improved behavioral responses indicative of reduced pain were observed in the model rats after administration of 10 mg/kg MA, concomitant with decreased expression levels of FTO and increased m6A methylation levels. Compared with untreated BCP rats, the expression levels of p-ERK and pro-inflammatory cytokines were also significantly decreased after MA administration. Taken together, FTO can downregulate m6A methylation level and activate ERK/inflammatory cytokines signaling pathway to maintain BCP in rats. [ABSTRACT FROM AUTHOR]

Metabolic memory (MM) is a major factor in the delayed wound healing observed in diabetic patients. While "Nocardia rubrum cell wall skeleton" (Nr-CWS) is utilized to enhance macrophage proliferation in immune diseases, its impact on MM wounds in diabetes is unclear. This study demonstrates that transient hyperglycemia leads to prolonged damage in vascular endothelial cells by decreasing METTL3 expression, leading to decreased RNA methylation and impaired cellular metabolism. Remarkably, Nr-CWS application increases METTL3 levels in these cells, facilitating the recovery of cell function. Further in vivo and in vitro analyses demonstrate that transient hyperglycemia-induced reduction in METTL3 hinders RNA methylation of the downstream gene Cds2, impacting mitochondrial function and energy metabolism and consequently reducing angiogenic capacity in endothelial cells. This impairment significantly influences diabetic wound healing. Our findings highlight the profound impact of transient hyperglycemia on wound healing, establishing METTL3 as a significant role in vascular complications of diabetes. This study not only elucidates the pathophysiological mechanisms behind MM in diabetic wounds but also suggests Nr-CWS as a potential therapeutic agent, offering a novel approach for treating diabetic wounds. METTL3 regulates RNA methylation and mitochondrial function in diabetic wound healing, highlighting Nocardia rubra cell wall skeleton as a potential therapeutic agent for improving vascular recovery in hyperglycemia-impaired wounds. [ABSTRACT FROM AUTHOR]

SUMMARY: As a dynamic and reversible post‐transcriptional marker, N6‐methyladenosine (m6A) plays an important role in the regulation of biological functions, which are mediated by m6A pathway components including writers (MT‐A70, FIP37, VIR and HAKAI family), erasers (ALKBH family) and readers (YTH family). There is an urgent need for a comprehensive analysis of m6A pathway components across species at evolutionary levels. In this study, we identified 4062 m6A pathway components from 154 plant species including green algae, utilizing large‐scale phylogenetic to explore their origin and evolution. We discovered that the copy number of writers was conserved among different plant lineages, with notable expansions in the ALKBH and YTH families. Synteny network analysis revealed conserved genomic contexts and lineage‐specific transpositions. Furthermore, we used Direct RNA Sequencing (DRS) to reveal the Poly(A) length (PAL) and m6A ratio profiles in six angiosperms species, with a particular focus on the m6A pathway components. The ECT1/2‐Poeaece4 sub‐branches (YTH family) with unique genomic contexts exhibited significantly higher expression level than genes of other ECT1/2 poeaece sub‐branches (ECT1/2‐Poeaece1‐3), accompanied by lower m6A modification and PAL. Besides, conserved m6A sites distributed in CDS and 3′UTR were detected in the ECT1/2‐Poaceae4, and the dual‐luciferase assay further demonstrated that these conserved m6A sites in the 3′UTR negatively regulated the expression of Firefly luciferase (LUC) gene. Finally, we developed transcription factor regulatory networks for m6A pathway components, using yeast one‐hybrid assay demonstrated that PheBPC1 could interact with the PheECT1/2‐5 promoter. Overall, this study presents a comprehensive evolutionary and functional analysis of m6A pathway components and their modifications in plants, providing a valuable resource for future functional analysis in this field. Significance Statement: In this study, the authors identified m6A pathway components from 154 plant species including green algae, utilizing large‐scale phylogenetic to explore their origin and evolution. Furthermore, the authors used Direct RNA Sequencing (DRS) to reveal the Poly(A) length and m6A ratio profiles in six angiosperms species, with a particular focus on the m6A pathway components. [ABSTRACT FROM AUTHOR]

Background: Lack of insight into factors that determine purity and quality of human iPSC (hiPSC)-derived neo-cartilage precludes applications of this powerful technology toward regenerative solutions in the clinical setting. Here, we set out to generate methylome-wide landscapes of hiPSC-derived neo-cartilages from different tissues-of-origin and integrated transcriptome-wide data to identify dissimilarities in set points of methylation with associated transcription and the respective pathways in which these genes act. Methods: We applied in vitro chondrogenesis using hiPSCs generated from two different tissue sources: skin fibroblasts and articular cartilage. Upon differentiation toward chondrocytes, these are referred to as hFiCs and hCiC, respectively. Genome-wide DNA methylation and RNA sequencing datasets were generated of the hiPSC-derived neo-cartilages, and the epigenetically regulated transcriptome was compared to that of neo-cartilage deposited by human primary articular cartilage (hPAC). Results: Methylome-wide landscapes of neo-cartilages of hiPSCs reprogrammed from two different somatic tissues were 85% similar to that of hPACs. By integration of transcriptome-wide data, differences in transcriptionally active CpGs between hCiC relative to hPAC were prioritized. Among the CpG-gene pairs lower expressed in hCiCs relative to hPACs, we identified genes such as MGP, GDF5, and CHAD enriched in closely related pathways and involved in cartilage development that likely mark phenotypic differences in chondrocyte states. Vice versa, among the CpG-gene pairs higher expressed, we identified genes such as KIF1A or NKX2-2 enriched in neurogenic pathways and likely reflecting off target differentiation. Conclusions: We did not find significant variation between the neo-cartilages derived from hiPSCs of different tissue sources, suggesting that application of a robust differentiation protocol such as we applied here is more important as compared to the epigenetic memory of the cells of origin. Results of our study could be further exploited to improve quality, purity, and maturity of hiPSC-derived neo-cartilage matrix, ultimately to realize introduction of sustainable, hiPSC-derived neo-cartilage implantation into clinical practice. [ABSTRACT FROM AUTHOR]

N6-methyladenosine (m6A) is considered the most prevalent methylation modification in messenger RNA (mRNA) that critically impacts head and neck cancer (HNC) pathogenesis and development. Alterations of m6A methylation related proteins are closely related to the progression, therapeutic effect, and prognosis of HNC. The human innate immune system activates immune pathways through pattern recognition receptors, which can not only resist pathogen infection, but also play a vital role in tumor immunity. Emerging evidence has confirmed that m6A methylation affects the activation of innate immune pathways such as TLR, cGAS-STING, and NLR by regulating RNA metabolism, revealing its potential mechanisms in the innate immune response of tumor cells. However, the relevant research is still in its infancy. This review elaborates the biological significance of RNA m6A methylation in HNC and discusses its potential regulatory relationship with TLR, cGAS-STING, and NLR pathways, providing a new perspective for in-depth understanding of the role of RNA methylation in the innate immune mechanism and therapeutic application of HNC. [ABSTRACT FROM AUTHOR]

Background: Muscle-invasive bladder carcinoma (MIBC) is a serious and more advanced stage of bladder carcinoma. N6-Methyladenosine (m6A) is a dynamic and reversible modifications that primarily affects RNA stability and alternative splicing. The dysregulation of m6A in MIBC can be potential target for clinical interventions, but there have been limited studies on m6A modifications in MIBC and their associations with post-transcriptional regulatory processes. Methods: Paired tumor and adjacent-normal tissues were obtained from three patients with MIBC following radical cystectomy. The additional paired tissues for validation were obtained from patients underwent transurethral resection. Utilizing Nanopore direct-RNA sequencing, we characterized the m6A RNA methylation landscape in MIBC, with a focus on identifying post-transcriptional events potentially affected by changes in m6A sites. This included an examination of differential transcript usage, polyadenylation signal sites, and variations in poly(A) tail length, providing insights into the broader impact of m6A alterations on RNA processing in MIBC. Results: The prognostic-related m6A genes and m6A-risk model constructed by machine learning enables the stratification of high and low-risk patients with precision. A novel m6A modification site in the 3' untranslated region (3'UTR) of IGLL5 gene were identified, characterized by a lower m6A methylation ratio, elongated poly(A) tails, and a notable bias in transcript usage. Furthermore, we discovered two particular transcripts, VWA1-203 and CEBPB-201. VWA1-203 displayed diminished m6A methylation levels, a truncated 3'UTR, and an elongated poly(A) tail, whereas CEBPB-201 showed opposite trends, highlighting the complex interplay between m6A modifications and RNA processing. Source code was provided on GitHub (https://github.com/lelelililele/Nanopore-m6A-analysis). Conclusions: The state-of-the-art Nanopore direct-RNA sequencing and machine learning techniques enables comprehensive identification of m6A modification and provided insights into the potential post-transcriptional regulation mechanisms on the development and progression in MIBC. [ABSTRACT FROM AUTHOR]

Mounting evidence has implicated the RNA m6A methylation catalyzed by METTL3 in a wide range of physiological and pathological processes, including tumorigenesis. The detailed m6A landscape and molecular mechanism of METTL3 in prostate cancer (PCa) remains ill-defined. We find that METTL3 is overexpressed in PCa and correlates with worse patient survival. Functional studies establish METTL3 as an oncoprotein dependent on its m6A enzymatic activity in both AR+ and AR− PCa cells. To dissect the regulatory network of m6A pathway in PCa, we map the m6A landscape in clinical tumor samples using m6A-seq and identify genome-wide METTL3-binding transcripts via RIP-seq. Mechanistically, we discover RRBP1 as a direct METTL3 target in which METTL3 stabilizes RRBP1 mRNA in an m6A-dependent manner. RRBP1 positively correlates with METTL3 expression in PCa cohorts and exerts an oncogenic role in aggressive PCa cells. Leveraging the 3D structural protein-protein interaction between METTL3 and METTL14, we successfully develop two potential METTL3 peptide inhibitors (RM3 and RSM3) that effectively suppress cancer cell proliferation in vitro and tumor growth in vivo. Collectively, our study reveals a novel METTL3/m6A/RRBP1 axis in enhancing aggressive traits of PCa, which can be therapeutically targeted by small-peptide METTL3 antagonists. [ABSTRACT FROM AUTHOR]

ABSTRACT Genetic mechanisms have been at the forefront of our exploration into the substrate of adaptive evolution and phenotypic diversification. However, genetic variation only accounts for a fraction of phenotypic variation. In the last decade, the significance of RNA modification mechanisms has become more apparent in the context of organismal adaptation to rapidly changing environments. RNA m6A methylation, the most abundant form of RNA modification, is emerging as a potentially significant player in various biological processes. Despite its fundamental function to regulate other major post‐transcriptional mechanisms such as microRNA and alternative splicing, its role in ecology and evolution has been understudied. This review highlights the potential importance of m6A RNA methylation in ecological adaptation, emphasising the need for further research, especially in natural systems. We focus on how m6A not only affects mRNA fate but also influences miRNA‐mediated gene regulation and alternative splicing, potentially contributing to organismal adaptation. The aim of this review is to synthesise key background information to enhance our understanding of m6A mechanisms driving species survival in dynamic environments and motivate future research into the dynamics of adaptive RNA methylation. [ABSTRACT FROM AUTHOR]

Methylation, a key epigenetic modification, is essential for regulating gene expression and protein function without altering the DNA sequence, contributing to various biological processes, including gene transcription, embryonic development, and cellular functions. Methylation encompasses DNA methylation, RNA methylation and histone modification. Recent research indicates that DNA methylation is vital for establishing and maintaining normal brain functions by modulating the high-order structure of DNA. Alterations in the patterns of DNA methylation can exert significant impacts on both gene expression and cellular function, playing a role in the development of numerous diseases, such as neurological disorders, cardiovascular diseases as well as cancer. Our current understanding of the etiology of neurological diseases emphasizes a multifaceted process that includes neurodegenerative, neuroinflammatory, and neurovascular events. Epigenetic modifications, especially DNA methylation, are fundamental in the control of gene expression and are critical in the onset and progression of neurological disorders. Furthermore, we comprehensively overview the role and mechanism of DNA methylation in in various biological processes and gene regulation in neurological diseases. Understanding the mechanisms and dynamics of DNA methylation in neural development can provide valuable insights into human biology and potentially lead to novel therapies for various neurological diseases. [ABSTRACT FROM AUTHOR]

Background: Temporal lobe epilepsy (TLE), a prevalent chronic neurological disorder, affects millions of individuals and is often resistant to anti‐epileptic drugs. Increasing evidence has shown that acetylcholine (ACh) and cholinergic neurotransmission play a role in the pathophysiology of epilepsy. Tropisetron, an antiemetic drug used for chemotherapy in clinic, has displayed potential in the treatment of Alzheimer's disease, depression, and schizophrenia in animal models. However, as a partial agonist of α7 nicotinic acetylcholine receptors (α7nAChRs), whether tropisetron possesses the therapeutic potential for TLE has not yet been determined. Methods: In this study, tropisetron was intraperitoneally injected into pilocarpine‐induced epileptic rats for 3 weeks. Alpha‐bungarotoxin (α‐bgt), a specific α7nAChR antagonist, was applied to investigate the mechanism of tropisetron. Rats were assessed for spontaneous recurrent seizures (SRS) and cognitive function using video surveillance and Morris's water maze testing. Hippocampal impairment and synaptic structure were evaluated by Nissl staining, immunohistochemistry, and Golgi staining. Additionally, the levels of glutamate, γ‐aminobutyric acid (GABA), ACh, α7nAChRs, neuroinflammatory cytokines, glucocorticoids and their receptors, as well as synapse‐associated protein (F‐actin, cofilin‐1) were quantified. Results: The results showed that tropisetron significantly reduced SRS, improved cognitive function, alleviated hippocampal sclerosis, and concurrently suppressed synaptic remodeling and the m6A modification of cofilin‐1 in TLE rats. Furthermore, tropisetron lowered glutamate levels without affecting GABA levels, reduced neuroinflammation, and increased ACh levels and α7nAChR expression in the hippocampi of TLE rats. The effects of tropisetron treatment were counteracted by α‐bgt. Conclusion: In summary, these findings indicate that tropisetron exhibits an anti‐epileptic effect and provides neuroprotection in TLE rats through the activation of α7nAChRs. The potential mechanism may involve the reduction of glutamate levels, enhancement of cholinergic transmission, and suppression of synaptic remodeling. Consequently, the present study not only highlights the potential of tropisetron as an anti‐epileptic drug but also identifies α7nAChRs as a promising therapeutic target for the treatment of TLE. [ABSTRACT FROM AUTHOR]

The aim of study was to investigate whether CASP8 (CASPASE8) could be a biomarker for prognosis in neuroblastoma. The prognostic value of CASP8 was determined by analyzing CASP8 methylation status and gene expressions in the tumor tissues of 37 neuroblastoma patients. Bisulfite and quantitative multiplex-methylation-specific polymerase chain reaction (PCR) were used to identify the methylation status. CASP8 messenger ribonucleic acid (RNA) expression levels were determined using reverse transcriptase–quantitative PCR. CASP8 expression levels associated with prognostic value were also analyzed using the TARGET NBL (141 cases) database through PDX for Childhood Cancer Therapeutics (PCAT) and SEQC (498 cases) via the R2 platform. CASP8 methylation status was associated with risk groups, MYCN amplification, and 17q gain status. CASP8 expression was found to be statistically different between high- and low-risk neuroblastoma groups. Low expression of CASP8 was associated with MYCN amplification status. Low expression of CASP8 has shown statistically significant prognostic value through TARGET NBL and SEQC-498 data sets. CASP8 messenger RNA expressions and methylation status were associated with the MYCN amplified high-risk group in neuroblastoma. CASP8 messenger RNA expressions may be considered as a clinical prognostic marker in neuroblastoma. [ABSTRACT FROM AUTHOR]

Immunotherapy has made great progress in various solid tumors. However, the "cold" tumor immune microenvironment of microsatellite stable subtype colorectal cancer (MSS‐CRC) hinders the effectiveness of immunotherapy. Therefore, reshaping the immunosuppressive microenvironment and initiating efficient antitumor immune responses are critical for immunotherapy of MSS‐CRC. According to the analysis of clinical samples, it is found that the levels of fat mass and obesity‐associated protein (FTO) and M2‐like tumor‐associated macrophages (TAMs) infiltration are significantly elevated in CRC tissue, which has driven one to construct a targeted cationic liposome to simultaneously enhance the RNA methylation and inhibit the CD47 immune checkpoint expression of tumor cells in the hope of promoting the M1‐like TAMs polarization and phagocytosis. By upregulating the m6A modification of tumor cells, the lactate secretion is decreased to promote the TAMs repolarized into M1‐like. Meanwhile, CD47 siRNA codelivered by the cationic liposomes downregulates the expression of immune checkpoint CD47 on the cancer cell surface, which enhances the phagocytic ability of the M1‐like TAMs. The combination treatment scheme is expected to provide a new option for treating MSS‐CRC, which may also be extended for treating other immunologically "cold" tumors. [ABSTRACT FROM AUTHOR]

Targeting RNA m6A marks in apoptosis-related transcripts holds promise for RNA therapeutics. However, pathway-specific RNA m6A sites on pro- or antiapoptotic transcripts have not been fully unveiled, let alone characterized. This article summarizes the current knowledge and gaps in the cellular response modulated by apoptotic stimulus-specific RNA m6A marks. [ABSTRACT FROM AUTHOR]

m6A modification is the most abundant mRNA modifications and plays an integral role in various biological processes in eukaryotes. However, the role of m6A regulators in rheumatoid arthritis remains unknown. To determine the expression of m6A RNA methylation regulators in rheumatoid arthritis and their possible functional and prognostic value. In this study, we performed differential analysis in the comprehensive gene expression database GSE93272 dataset between non-rheumatoid arthritis patients and rheumatoid arthritis patients to obtain 15 important m6A regulators. A random forest model and lasso regression were used to screen the five most important m6A regulators to predict the risk of developing rheumatoid arthritis. After further validation using in vitro qPCR experiments, a nomogram model was developed based on the four most important m6A regulators (ELAVL1, WTAP, YTHDF1, and ALKBH5). Immuno-infiltration analysis and consensus clustering analysis were then performed. An analysis of the decision curve showed that the nomogram model could be beneficial to patients. According to selected important m6A regulators, patients with rheumatoid arthritis were classified into two m6A models (ClusterA and ClusterB) via consensus approach. Activated B cells, CD56dim natural killer cells, immature B cells, monocytes, natural killer T cells, and T lymphocytes were associated with ClusterA in immune infiltration analysis. Importantly, immune infiltration in patients with high ELAVL1 expression was strikingly similar to ClusterA. m6A regulators play a non-negligible role in the development of rheumatoid arthritis. A study of m6A patterns may provide future therapeutic options for rheumatoid arthritis. [ABSTRACT FROM AUTHOR]

Naked mole-rats, Heterocephalus glaber , are champion hypoxia-tolerant rodents that live under low oxygen conditions in their subterranean burrows. Detrimental effects of low oxygen can be mitigated through metabolic rate depression (MRD), metabolic reorganization, and global downregulation of nonessential cellular processes. Recent research has progressively implicated epigenetic modifications – rapid, reversible changes to gene expression that do not alter the DNA sequence itself – as major players in implementing and maintaining MRD. N6-adenosine (m6A) methylation is the most prevalent mammalian RNA modification and is responsible for pre-mRNA processing and mRNA export from the nucleus. Hence, m6A -mediated conformational changes alter the cellular fate of transcripts. The present study investigated the role of m6A RNA methylation responses to 24 h of hypoxia exposure in H. glaber cardiac tissue. Total protein levels of m6A writers/readers/erasers, m6A demethylase activity, and total m6A quantification were measured under normoxic vs. hypoxic conditions in H. glaber heart. While there was no change in either demethylase activity or total m6A content, many proteins of the m6A pathway were downregulated during hypoxia. Overall, m6A may not be a signature hypoxia-responsive characteristic in H. glaber heart, but downregulation of the protein machinery involved in m6A cycling points to an alternate biological involvement. Further research will explore other forms of RNA modifications and other epigenetic mechanisms to determine the controls on hypoxia endurance in this subterranean mammal. • Broadly, total protein levels of RNA m6A machinery decreased during hypoxia. • There was no change in demethylase activity or total m6A in normoxia vs. hypoxia. • There was a marked upregulation in eIF3a protein expression during hypoxia. • Upregulation of eIF3a may link to AMPK activation and/or mTOR inhibition. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the effect of the N6-methyladenosine (m6A) dependent ferroptosis on cisplatin-induced Sertoli cell injury. Materials and Methods: A cisplatin exposure mouse model was established by intraperitoneal injection of cisplatin in our study. TM4 cell lines was used for in vitro study. Ferroptosis was detected according to metabolomic analysis and a series of assays, including malondialdehyde, glutathione, and glutathione disulfide concentration detection, 2',7'-dichlorodihydrofluo-rescein diacetate and BODIPY 581/591 C11 probe detection, and transmission electron microscope imaging. Key ferroptosis-related genes were identified via transcriptomic analysis, western blot and immunohistochemistry. The m6A modification was demonstrated via m6A RNA immunoprecipitation and luciferase reporter assays. Immune cell infiltration was detected by mass cytometry, and verified by flow cytometry and immunofluorescence. Results: Ferroptosis, but not other types of programmed cell death, is a significant phenomenon in cisplatin-induced testis damage and Sertoli cell loss. Ferroptosis induced by cisplatin in Sertoli cell/TM4 cell is GPX4 independent but is regulated by SLC7A11 and ALOX12. Both SLC7A11 and ALOX12 are regulated via m6A dependent manner by METTL3. Furthermore, overexpressed ALOX12-12HETE pathway may result in macrophage polarization and inflammatory response in cisplatin exposure testis. Conclusions: Cisplatin-induced Sertoli cell injury via ferroptosis and promoted ferroptosis in an m6A dependent manner. m6A modification of both SLC7A11 and ALOX12 mRNA could result in ferroptosis in our in vitro model. Further, overexpressed ALOX12 can cause more production of 12-HETE, which may be responsible for testis inflammation caused by cisplatin. [ABSTRACT FROM AUTHOR]

Objective: N6‐methyladenosine (m6A) is the most prevalent modification of RNA in eukaryotes which is associated with many cellular processes and diseases. Here, our objective is to explore whether genetic variants in m6A modification genes are associated with the risk of non‐syndrome orofacial clefts (NSOCs). Methods: The transmission disequilibrium test (TDT) was performed to calculate the association between single nucleotide polymorphisms (SNPs) in m6A modification genes and NSOCs risk in 944 case‐parent trios. The function of SNP was predicted by HaploReg, RegulomeDB and histone enrichment data. The expression quantitative trait locus (eQTL) analysis was examined using Genotype‐Tissue Expression (GTEx) and eQTLGen. The role of gene in the development of NSOCs was assessed with correlation and enrichment analysis based on gene expression data in mice craniofacial tissue and zebrafish embryo. Results: We identified that rs8078195 (A > C) in METTL16 was suggestively associated with the increased risk of NSOCs (OR = 1.32, p = 1.80E − 03). The region surrounding rs8078195 was subjected to deoxyribonuclease hypersensitivity and enriched with multiple histone modifications. In addition, it had a significant eQTL effect with METTL16 in skin tissue and human peripheral blood, which played an important role in NSOCs development. Bioinformatic analysis indicated that METTL16 contributed to the development of NSOCs probably by regulating cell cycle process. Conclusions: Rs8078195 in METTL16 was associated with the occurrence of NSOCs. [ABSTRACT FROM AUTHOR]

N6-methyladenosine (m6A) is a RNA modification that can regulate post-transcriptional processes including RNA stability, translation, splicing, and nuclear export. In CD4+ lymphocytes, m6A modifications have been demonstrated to play a role in early differentiation processes. The role of m6A in CD4+ T cell activation and effector function remains incompletely understood. To assess the role of m6A in CD4+ T lymphocyte activation and function, we assessed the transcriptome-wide m6A landscape of human primary CD4+ T cells by methylated RNA immunoprecipitation sequencing. Stimulation of the T cells impacted the m6A pattern of hundreds of transcripts including tumor necrosis factor (TNF). m6A methylation was increased on TNF messenger RNA (mRNA) after activation, predominantly in the 3′ untranslated region of the transcript. Manipulation of m6A levels in primary human T cells, the directly affected the expression of TNF. Furthermore, we identified that the m6A reader protein YTHDF2 binds m6A-methylated TNF mRNA, and promotes its degradation. Taken together, this study demonstrates that TNF expression in CD4+ T lymphocytes is regulated via m6A and YTHDF2, thereby providing novel insight into the regulation of T cell effector functions. [ABSTRACT FROM AUTHOR]

Climate change has emerged as a crucial global issue that significantly threatens the survival of plants. In particular, low temperature (LT) is one of the critical environmental factors that influence plant morphological, physiological, and biochemical changes during both the vegetative and reproductive growth stages. LT, including abrupt drops in temperature, as well as winter conditions, can cause detrimental effects on the growth and development of tomato plants, ranging from sowing, transplanting, truss appearance, flowering, fertilization, flowering, fruit ripening, and yields. Therefore, it is imperative to understand the comprehensive mechanisms underlying the adaptation and acclimation of tomato plants to LT, from the morphological changes to the molecular levels. In this review, we discuss the previous and current knowledge of morphological, physiological, and biochemical changes, which contain vegetative and reproductive parameters involving the leaf length (LL), plant height (PH) stem diameter (SD), fruit set (FS), fruit ripening (FS), and fruit yield (FY), as well as photosynthetic parameters, cell membrane stability, osmolytes, and ROS homeostasis via antioxidants scavenging systems during LT stress in tomato plants. Moreover, we highlight recent advances in the understanding of molecular mechanisms, including LT perception, signaling transduction, gene regulation, and fruit ripening and epigenetic regulation. The comprehensive understanding of LT response provides a solid basis to develop the LT-resistant varieties for sustainable tomato production under the ever-changing temperature fluctuations. [ABSTRACT FROM AUTHOR]

New biomarkers for early diagnosis of gastric cancer (GC), the second leading cause of cancer‐related death, are urgently needed. IGFBP7, known to play various roles in multiple tumours, is complexly regulated across diverse cancer types, as evidenced by our pancancer analysis. Bioinformatics analysis revealed that IGFBP7 expression was related to patient prognosis, tumour clinicopathological characteristics, tumour stemness, microsatellite instability and immune cell infiltration, as well as the expression of oncogenes and immune checkpoints. GSEA links IGFBP7 to several cancer‐related pathways. IGFBP7 deficiency inhibited GC cell proliferation and migration in vitro. Furthermore, an in vivo nude mouse model revealed that IGFBP7 downregulation suppressed the tumorigenesis of GC cells. Western blotting analysis showed that the JAK1/2‐specific inhibitor ruxolitinib could rescue alterations induced by IGFBP7 overexpression in GC cells. Additionally, our bioinformatics analysis and in vitro assays suggested that IGFBP7 is regulated by DNA methylation at the genetic level and that the RNA m6A demethylase FTO modulates it at the posttranscriptional level. This study emphasizes the clinical relevance of IGFBP7 in GC and its influence on cell proliferation and migration via the JAK/STAT signalling pathway. This study also highlights the regulation of IGFBP7 in GC by DNA and m6A RNA methylation. [ABSTRACT FROM AUTHOR]

Resveratrol, a natural compound found in various plants, is known for its anti‐inflammatory, antioxidant, and senescence‐delaying properties. RNA N6‐methyladenosine (m6A) methylation plays a crucial role in oxidative stress and premature cellular senescence processes and is closely associated with age‐related disorders. However, the anti‐premature senescence via RNA m6A methylation mechanism of resveratrol is still not fully understood. In this study, based on premature senescence model of human embryonic lung fibroblasts (HEFs) induced by hydrogen peroxide (H2O2), a widely accepted model of premature senescence caused by oxidative stress, we explored the anti‐aging regulatory effects of resveratrol at the RNA m6A methylation level. Our data suggested that resveratrol significantly delayed premature senescence by increasing cell viability, reducing SA‐β‐gal blue staining rate, ROS levels, and senescence‐associated secretory phenotypes (SASP) expression in HEFs. Meanwhile, resveratrol increased the whole RNA methyltransferases activity and the overall m6A level during senescence. Furthermore, three genes CCND2, E2F1, and GADD45B have been identified as the main ones regulating premature by resveratrol. Specifically, it decreased E2F1, GADD45B RNA m6A methylation level, and increased CCND2 level in premature cells. Our study provided new clues for exploring the mechanism and application of resveratrol in the field of premature aging. [ABSTRACT FROM AUTHOR]

Background: N6-methyladenosine (m6A) modification of messenger RNA (mRNA) is crucial for liquid-liquid phase separation in mammals. Increasing evidence indicates that liquid-liquid phase separation in proteins and RNAs affects diabetic cardiomyopathy. However, the molecular mechanism by which m6A-mediated phase separation regulates diabetic cardiac fibrosis remains elusive. Methods: Leptin receptor-deficient mice (db/db), cardiac fibroblast-specific Notch1 conditional knockout (POSTN-Cre × Notch1flox/flox) mice, and Cre mice were used to induce diabetic cardiac fibrosis. Adeno-associated virus 9 carrying cardiac fibroblast-specific periostin (Postn) promoter-driven small hairpin RNA targeting Alkbh5, Ythdf2, or Notch1, and the phase separation inhibitor 1,6-hexanediol were administered to investigate their roles in diabetic cardiac fibrosis. Histological and biochemical analyses were performed to determine how Alkbh5 and Ythdf2 regulate Notch1 expression in diabetic cardiac fibrosis. NOTCH1 was reconstituted in ALKBH5- and YTHDF2-deficient cardiac fibroblasts and mouse hearts to study its effects on mitochondrial fission and diabetic cardiac fibrosis. Heart tissue samples from patients with diabetic cardiomyopathy were used to validate our findings. Results: In mice with diabetic cardiac fibrosis, decreased Notch1 expression was accompanied by high m6A mRNA levels and mitochondrial fission. Fibroblast-specific deletion of Notch1 enhanced mitochondrial fission and cardiac fibroblast proliferation and induced diabetic cardiac fibrosis in mice. Notch1 downregulation was associated with Alkbh5-mediated m6A demethylation in the 3'UTR of Notch1 mRNA and elevated m6A mRNA levels. These elevated m6A levels in Notch1 mRNA markedly enhanced YTHDF2 phase separation, increased the recognition of m6A residues in Notch1 mRNA by YTHDF2, and induced Notch1 degradation. Conversely, epitranscriptomic downregulation rescues Notch1 expression, resulting in the opposite effects. Human heart tissues from patients with diabetic cardiomyopathy were used to validate the findings in mice with diabetic cardiac fibrosis. Conclusions: We identified a novel epitranscriptomic mechanism by which m6A-mediated phase separation suppresses Notch1 expression, thereby promoting mitochondrial fission in diabetic cardiac fibrosis. Our findings provide new insights for the development of novel treatment approaches for patients with diabetic cardiac fibrosis. [ABSTRACT FROM AUTHOR]

N6-methyladensine (m6 A) has been identified as the best-characterized and the most abundant mRNA modification in eukaryotes. It can be dynamically regulated, removed, and recognized by its specific cellular components (respectively called "writers,""erasers,""readers") and have become a hot research field in a variety of biological processes and diseases. Currently, the underlying molecular mechanisms of m6 A epigenetic modification in diabetes mellitus (DM) and diabetic microvascular complications have not been extensively clarified. In this review, we focus on the effects and possible mechanisms of m6 A as possible potential biomarkers and therapeutic targets in the treatment of DM and diabetic microvascular complications. [ABSTRACT FROM AUTHOR]

Background: Methyltransferase 3 (METTL3) accelerates N6‐methyladenosine (m6A) modifications and affects cancer progression, including non‐small‐cell lung cancer (NSCLC). In this study, we aimed to explore the regulatory mechanisms of METTL3 underling NSCLC. Methods: Immunohistochemical assay, quantitative real‐time polymerase chain reaction (qRT‐PCR) assay, and western blot assay were conducted for gene expression. MTT assay and colony formation assay were performed to explore cell proliferation capacity. Cell apoptosis and THP‐1 cell polarization were estimated by flow cytometry analysis. Cell migration and invasion capacities were evaluated by transwell assay. Methylated RNA immunoprecipitation assay, dual‐luciferase reporter assay, actinomycin D treatment and RIP assay were performed to analyze the relationships of METTL3, insulin‐like growth factor 2 mRNA binding protein 1 (IGF2BP1), and transient receptor potential cation channel subfamily V member 1 (TRPV1). The functions of METTL3 and TRPV1 in vivo were investigated through establishing the murine xenograft model. Results: TRPV1 expression was upregulated in NSCLC and related poor prognosis. TRPV1 silencing inhibited NSCLC cell growth and metastasis, induced NSCLC cell apoptosis, and repressed M2 macrophage polarization. The results showed that METTL3 and IGF2BP1 could regulate TRPV1 expression through m6A methylation modification. Moreover, METTL3 deficiency inhibited NSCLC cell growth, metastasis, and M2 macrophage polarization and facilitated NSCLC cell apoptosis, while TRPV1 overexpression restored the impacts. In addition, METTL3 knockdown restrained tumor growth in vivo via regulating TRPV1 expression. Conclusion: METTL3 bound to IGF2BP1 and enhanced IGF2BP1's m6A recognition of TRPV1 mRNA, thereby promoting NSCLC cell growth and metastasis, and inhibiting M2 macrophage polarization. [ABSTRACT FROM AUTHOR]

Skeletal muscle development is spotlighted in mammals since it closely relates to animal health and economic benefits to the breeding industry. Researchers have successfully unveiled many regulatory factors and mechanisms involving myogenesis. However, the effect of N6-methyladenosine (m6A) modification, especially demethylase and its regulated genes, on muscle development remains to be further explored. Here, we found that the typical demethylase FTO (fat mass- and obesity-associated protein) was highly enriched in goats' longissimus dorsi (LD) muscles. In addition, the level of m6A modification on transcripts was negatively regulated by FTO during the proliferation of goat skeletal muscle satellite cells (MuSCs). Moreover, a deficiency of FTO in MuSCs significantly retarded their proliferation and promoted the expression of dystrophin-associated protein 1 (DAG1). m6A modifications of DAG1 mRNA were efficiently altered by FTO. Intriguingly, the results of DAG1 levels and its m6A enrichment from FB23-2 (FTO demethylase inhibitor)-treated cells were consistent with those of the FTO knockdown, indicating that the regulation of FTO on DAG1 depended on m6A modification. Further experiments showed that interfering FTO improved m6A modification at site DAG1-122, recognized by Insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) and consequently stabilized DAG1 transcripts. Our study suggests that FTO promotes the proliferation of MuSCs by regulating the expression of DAG1 through m6A modification. This will extend our knowledge of the m6A-related mechanism of skeletal muscle development in animals. [ABSTRACT FROM AUTHOR]

Myelodysplastic syndromes (MDS) are myeloid malignancies with heterogeneous genotypes and phenotypes, characterized by ineffective haematopoiesis and a high risk of progression towards acute myeloid leukaemia (AML). Prognosis for patients treated with hypomethylating agents (HMAs), as is azacytidine, the main drug used as frontline therapy for MDS is mostly based on cytogenetics and next generation sequencing (NGS) of the initial myeloid clone. Although the critical influence of the epigenetic landscape upon cancer cells survival and development as well on tumour environment establishment is currently recognized and approached within current clinical practice in MDS, the heterogenous response of the patients to epigenetic therapy is suggesting a more complex mechanism of action, as is the case of RNA methylation. In this sense, the newly emerging field of epitranscriptomics could provide a more comprehensive perspective upon the modulation of gene expression in malignancies, as is the proof‐of‐concept of MDS. We initially did RNA methylation sequencing on MDS patients (n = 6) treated with azacytidine and compared responders with non‐responders. Afterwards, the genes identified were assessed in vitro and afterwards validated on a larger cohort of MDS patients treated with azacytidine (n = 58). Our data show that a more accurate prognosis could be based on analysing the methylome and thus we used methylation sequencing to differentially split high‐grade MDS patients with identical demographical and cytogenetic features, between azacytidine responders and non‐responders. [ABSTRACT FROM AUTHOR]

Human umbilical cord mesenchymal stem cell-derived exosomes (hucMSC-Ex) have emerged as a new treatment strategy for inflammatory bowel disease (IBD) due to their immunoregulatory function. N6-methyladenosine (m6A) plays a crucial role in regulating intestinal immunity, especially in IBD where macrophages play an important role, although its mechanism is not yet fully understood. From this perspective, this research aimed to evaluate the effect of hucMSC-Ex on m6A modification of macrophages in IBD. In the process of alleviating inflammation, hucMSC-Ex promotes macrophage polarization toward the M2 type and regulates intracellular m6A levels by upregulating the expression of m6A "Writer" METTL3 and "Reader" YTHDF1. Solute Carrier Family 37 Member 2 (Slc37a2) was identified by Methylation RNA immunoprecipitation sequencing as the target molecule of the hucMSC-Ex. Mechanically, hucMSC-Ex promoted the binding of METTL3 to the Slc37a2 mRNA complex, and enhanced the binding of Slc37a2 to YTHDF1 to upregulate the intracellular expression of Slc37a2, thereby attenuating the pro-inflammatory function of macrophage. This study confirms the modulatory role of hucMSC-Ex on the m6A modification of macrophages in IBD, providing a new scientific basis for the treatment of IBD with hucMSC-Ex. [ABSTRACT FROM AUTHOR]

Gene expression is an intricate biological process that bridges gap between the genotype and the phenotype. Canonical and hereditable epigenetic mechanisms, such as histone and DNA modifications, regulate the release of genetic information encoded in DNA without altering the underlying sequence. Many other non-canonical players, such as chromatin regulators and noncoding RNAs, are also involved in regulating gene expression. Recently, RNA modifications (epitranscriptomics) have been shown to hold enormous potential in shaping cellular transcriptomes. However, their co-transcriptional nature and uncertain heritability mean that they fall outside the current definition of epigenetics, sparking an ongoing debate in the field. Here we will discuss the relationship between canonical and non-canonical epigenetic mechanisms that govern gene expression and offer our perspective on whether (or not) epitranscriptomic modifications can be classified as epigenetic mechanisms. [ABSTRACT FROM AUTHOR]

Neuroepithelial tumors with fusion of PLAGL1 or amplification of PLAGL1/PLAGL2 have recently been described often with ependymoma-like or embryonal histology respectively. To further evaluate emerging entities with PLAG-family genetic alterations, the histologic, molecular, clinical, and imaging features are described for 8 clinical cases encountered at St. Jude (EWSR1-PLAGL1 fusion n = 6; PLAGL1 amplification n = 1; PLAGL2 amplification n = 1). A histologic feature observed on initial resection in a subset (4/6) of supratentorial neuroepithelial tumors with EWSR1-PLAGL1 rearrangement was the presence of concurrent ependymal and ganglionic differentiation. This ranged from prominent clusters of ganglion cells within ependymoma/subependymoma-like areas, to interspersed ganglion cells of low to moderate frequency among otherwise ependymal-like histology, or focal areas with a ganglion cell component. When present, the combination of ependymal-like and ganglionic features within a supratentorial neuroepithelial tumor may raise consideration for an EWSR1-PLAGL1 fusion, and prompt initiation of appropriate molecular testing such as RNA sequencing and methylation profiling. One of the EWSR1-PLAGL1 fusion cases showed subclonal INI1 loss in a region containing small clusters of rhabdoid/embryonal cells, and developed a prominent ganglion cell component on recurrence. As such, EWSR1-PLAGL1 neuroepithelial tumors are a tumor type in which acquired inactivation of SMARCB1 and development of AT/RT features may occur and lead to clinical progression. In contrast, the PLAGL2 and PLAGL1 amplified cases showed either embryonal histology or contained an embryonal component with a significant degree of desmin staining, which could also serve to raise consideration for a PLAG entity when present. Continued compilation of associated clinical data and histopathologic findings will be critical for understanding emerging entities with PLAG-family genetic alterations. [ABSTRACT FROM AUTHOR]

The molecular mechanisms underlying age‐related declines in learning and long‐term memory are still not fully understood. To address this gap, our study focused on investigating the transcriptional landscape of a singularly identified motor neuron L7 in Aplysia, which is pivotal in a specific type of nonassociative learning known as sensitization of the siphon‐withdraw reflex. Employing total RNAseq analysis on a single isolated L7 motor neuron after short‐term or long‐term sensitization (LTS) training of Aplysia at 8, 10, and 12 months (representing mature, late mature, and senescent stages), we uncovered aberrant changes in transcriptional plasticity during the aging process. Our findings specifically highlight changes in the expression of messenger RNAs (mRNAs) that encode transcription factors, translation regulators, RNA methylation participants, and contributors to cytoskeletal rearrangements during learning and long noncoding RNAs (lncRNAs). Furthermore, our comparative gene expression analysis identified distinct transcriptional alterations in two other neurons, namely the motor neuron L11 and the giant cholinergic neuron R2, whose roles in LTS are not yet fully elucidated. Taken together, our analyses underscore cell type‐specific impairments in the expression of key components related to learning and memory within the transcriptome as organisms age, shedding light on the complex molecular mechanisms driving cognitive decline during aging. [ABSTRACT FROM AUTHOR]

N6-methyladenosine (m |$^{6}$| A) is a widely-studied methylation to messenger RNAs, which has been linked to diverse cellular processes and human diseases. Numerous databases that collate m |$^{6}$| A profiles of distinct cell types have been created to facilitate quick and easy mining of m |$^{6}$| A signatures associated with cell-specific phenotypes. However, these databases contain inherent complexities that have not been explicitly reported, which may lead to inaccurate identification and interpretation of m |$^{6}$| A-associated biology by end-users who are unaware of them. Here, we review various m |$^{6}$| A-related databases, and highlight several critical matters. In particular, differences in peak-calling pipelines across databases drive substantial variability in both peak number and coordinates with only moderate reproducibility, and the inclusion of peak calls from early m |$^{6}$| A sequencing protocols may lead to the reporting of false positives or negatives. The awareness of these matters will help end-users avoid the inclusion of potentially unreliable data in their studies and better utilize m |$^{6}$| A databases to derive biologically meaningful results. [ABSTRACT FROM AUTHOR]

RNA methylation plays a central regulatory role in plant biology and is a relatively new target for plant improvement efforts. In nearly all cases, perturbation of the RNA methylation machinery results in deleterious phenotypes. However, a recent landmark paper reported that transcriptome‐wide use of the human RNA demethylase FTO substantially increased the yield of rice and potatoes. Here, we have performed the first independent replication of those results and demonstrated broader transferability of the trait, finding increased flower and fruit count in the model species Arabidopsis thaliana. We also performed RNA‐seq of our FTO‐transgenic plants, which we analyzed in conjunction with previously published datasets to detect several previously unrecognized patterns in the functional and structural classification of the upregulated and downregulated genes. From these, we present mechanistic hypotheses to explain these surprising results with the goal of spurring more widespread interest in this promising new approach to plant engineering. [ABSTRACT FROM AUTHOR]

Main conclusion: This study revealed the transcriptome-wide m6A methylation profile under drought stress and found thatTaETC9 might regulate drought tolerance through mediating RNA methylation in wheat. Drought is one of the most destructive environmental constraints limiting crop growth and development. N6-methyladenosine (m6A) is a prevalent and important post-transcriptional modification in various eukaryotic RNA molecules, playing the crucial role in regulating drought response in plants. However, the significance of m6A in wheat (Triticum aestivum L.), particularly its involvment in drought response, remains underexplored. In this study, we investigated the transcriptome-wide m6A profile under drought stress using parallel m6A immunoprecipitation sequencing (MeRIP-seq). Totally, 4221 m6A peaks in 3733 m6A-modified genes were obtained, of which 373 methylated peaks exhibited differential expression between the control (CK) and drought-stressed treatments. These m6A loci were significantly enriched in proximity to stop codons and within the 3′-untranslated region. Integration of MeRIP-seq and RNA-seq revealed a positive correlation between m6A methylation and mRNA abundance and the genes displaying both differential methylation and expression were obtained. Finally, qRT-PCR analyses were further performed and the results found that the m6A-binding protein (TaETC9) showed significant up-regulation, while the m6A demethylase (TaALKBH10B) was significantly down-regulated under drought stress, contributing to increased m6A levels. Furthermore, the loss-of-function mutant of TaECT9 displayed significantly higher drought sensitivity compared to the wild type, highlighting its role in regulating drought tolerance. This study reported the first wheat m6A profile associated with drought stress, laying the groundwork for unraveling the potential role of RNA methylation in drought responses and enhancing stress tolerance in wheat through epigenetic approaches. [ABSTRACT FROM AUTHOR]

Abstract Background N 6-methyladenosine (m6A) modification of messenger RNA (mRNA) is crucial for liquid-liquid phase separation in mammals. Increasing evidence indicates that liquid-liquid phase separation in proteins and RNAs affects diabetic cardiomyopathy. However, the molecular mechanism by which m6A-mediated phase separation regulates diabetic cardiac fibrosis remains elusive. Methods Leptin receptor-deficient mice (db/db), cardiac fibroblast-specific Notch1 conditional knockout (POSTN-Cre × Notch1flox/flox) mice, and Cre mice were used to induce diabetic cardiac fibrosis. Adeno-associated virus 9 carrying cardiac fibroblast-specific periostin (Postn) promoter-driven small hairpin RNA targeting Alkbh5, Ythdf2, or Notch1, and the phase separation inhibitor 1,6-hexanediol were administered to investigate their roles in diabetic cardiac fibrosis. Histological and biochemical analyses were performed to determine how Alkbh5 and Ythdf2 regulate Notch1 expression in diabetic cardiac fibrosis. NOTCH1 was reconstituted in ALKBH5- and YTHDF2-deficient cardiac fibroblasts and mouse hearts to study its effects on mitochondrial fission and diabetic cardiac fibrosis. Heart tissue samples from patients with diabetic cardiomyopathy were used to validate our findings. Results In mice with diabetic cardiac fibrosis, decreased Notch1 expression was accompanied by high m6A mRNA levels and mitochondrial fission. Fibroblast-specific deletion of Notch1 enhanced mitochondrial fission and cardiac fibroblast proliferation and induced diabetic cardiac fibrosis in mice. Notch1 downregulation was associated with Alkbh5-mediated m6A demethylation in the 3’UTR of Notch1 mRNA and elevated m6A mRNA levels. These elevated m6A levels in Notch1 mRNA markedly enhanced YTHDF2 phase separation, increased the recognition of m6A residues in Notch1 mRNA by YTHDF2, and induced Notch1 degradation. Conversely, epitranscriptomic downregulation rescues Notch1 expression, resulting in the opposite effects. Human heart tissues from patients with diabetic cardiomyopathy were used to validate the findings in mice with diabetic cardiac fibrosis. Conclusions We identified a novel epitranscriptomic mechanism by which m6A-mediated phase separation suppresses Notch1 expression, thereby promoting mitochondrial fission in diabetic cardiac fibrosis. Our findings provide new insights for the development of novel treatment approaches for patients with diabetic cardiac fibrosis.

Abstract Breast cancer (BC) is a highly prevalent malignancy worldwide, with complex pathogenesis and treatment challenges. Research reveals that methyltransferase-like 3 (METTL3) is widely involved in the pathogenesis of several tumors through methylation of its target RNAs, and its role and mechanisms in BC are also extensively studied. In this review, we aim to provide a comprehensive interpretation of available studies and elucidate the relationship between METTL3 and BC. This review suggests that high levels of METTL3 are associated with the pathogenesis, poor prognosis, and drug resistance of BC, suggesting METTL3 as a potential diagnostic or prognostic biomarker and therapeutic target. Collectively, this review provides a comprehensive understanding of how METTL3 functions through RNA methylation, which provides a valuable reference for future fundamental studies and clinical applications.

Abstract RNA methylation, a prevalent post-transcriptional modification, has garnered considerable attention in research circles. It exerts regulatory control over diverse biological functions by modulating RNA splicing, translation, transport, and stability. Notably, studies have illuminated the substantial impact of RNA methylation on tumor immunity. The primary types of RNA methylation encompass N6-methyladenosine (m6A), 5-methylcytosine (m5C), N1-methyladenosine (m1A), and N7-methylguanosine (m7G), and 3-methylcytidine (m3C). Compelling evidence underscores the involvement of RNA methylation in regulating the tumor microenvironment (TME). By affecting RNA translation and stability through the "writers", "erasers" and "readers", RNA methylation exerts influence over the dysregulation of immune cells and immune factors. Consequently, RNA methylation plays a pivotal role in modulating tumor immunity and mediating various biological behaviors, encompassing proliferation, invasion, metastasis, etc. In this review, we discussed the mechanisms and functions of several RNA methylations, providing a comprehensive overview of their biological roles and underlying mechanisms within the tumor microenvironment and among immunocytes. By exploring how these RNA modifications mediate tumor immune evasion, we also examine their potential applications in immunotherapy. This review aims to provide novel insights and strategies for identifying novel targets in RNA methylation and advancing cancer immunotherapy efficacy.

Abstract The primary objective of this study is to understand the regulatory role of epigenetics in thyroid-associated ophthalmopathy (TAO) using multi-omics sequencing data. We utilized tRFs sequencing data, DNA methylation sequencing data, and lncRNA/circRNA/mRNA sequencing data, as well as several RNA methylation target prediction websites, to analyze the regulatory effect of DNA methylation, non-coding RNA, and RNA methylation on TAO-associated genes. Through differential expression analysis, we identified 1019 differentially expressed genes, 985 differentially methylated genes, and 2601 non-coding RNA. Functional analysis showed that differentially expressed genes were mostly associated with the PI3K signaling pathway and the IL17 signaling pathway. Genes regulated by DNA epigenetic regulatory networks were mainly related to the Cytokine-cytokine receptor interaction pathway, whereas genes regulated by RNA epigenetic regulatory networks were primarily related to the T cell receptor signaling pathway. Finally, our integrated regulatory network analysis revealed that epigenetics mainly impacts the occurrence of TAO through its effects on key pathways such as cell killing, cytokine production, and immune response. In summary, this study is the first to reveal a new mechanism underlying the development of TAO and provides new directions for future TAO research.

Protein methylation is a functionally important post-translational modification that occurs on diverse amino acid residues. The current proteomics approaches are inefficient to discover the methylation on residues other than Arg and Lys, which hinders the deep understanding of the functional role of rare protein methylation. Herein, we present a methyl-specific metabolic labeling approach for global methylome mapping, which enable the acquisition of methylome dataset covering diverse methylation types. Interestingly, of the identified methylation events, His methylation is found to be preferably occurred in C3H1 zinc fingers (ZFs). These His methylation events are determined to be Nπ specific and catalyzed by CARNMT1. The His methylation is found to stabilize the structure of ZFs. U2AF1 is used as a proof-of-concept to highlight the functional importance of His methylation in ZFs in RNA binding and RNA metabolism. The results of this study enable novel understanding of how protein methylation regulates cellular processes. Here the authors developed a methyl-specific metabolic labeling approach for global analysis covering diverse methylation types. His methylation is found in C3H1 zinc fingers. U2AF1 is used to highlight the role of His methylation in ZFs in RNA metabolism. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is a neurodegenerative disorder caused by a variety of factors, including age, genetic susceptibility, cardiovascular disease, traumatic brain injury, and environmental factors. The pathogenesis of AD is largely associated with the overproduction and accumulation of amyloid-β peptides and the hyperphosphorylation of tau protein in the brain. Recent studies have identified the presence of diverse pathogens, including viruses, bacteria, and parasites, in the tissues of AD patients, underscoring the critical role of central nervous system infections in inducing pathological changes associated with AD. Nevertheless, it remains unestablished about the specific mechanism by which infections lead to the occurrence of AD. As an important post-transcriptional RNA modification, RNA 5-methylcytosine (m5C) methylation regulates a wide range of biological processes, including RNA splicing, nuclear export, stability, and translation, therefore affecting cellular function. Moreover, it has been recently demonstrated that multiple pathogenic microbial infections are associated with the m5C methylation of the host. However, the role of m5C methylation in infectious AD is still uncertain. Therefore, this review discusses the mechanisms of pathogen-induced AD and summarizes research on the molecular mechanisms of m5C methylation in infectious AD, thereby providing new insight into exploring the mechanism underlying infectious AD. [ABSTRACT FROM AUTHOR]

Background: Tumor recurrence and mortality rates remain challenging in cancer patients despite comprehensive treatment. Neoadjuvant chemotherapy and immunotherapy aim to eliminate residual tumor cells, reducing the risk of recurrence. However, drug resistance during neoadjuvant therapy is a significant hurdle. Recent studies suggest a correlation between RNA methylation regulators (RMRs) and response to neoadjuvant therapy. Methods: Using a multi-center approach, we integrated advanced techniques such as single-cell transcriptomics, whole-genome sequencing, RNA sequencing, proteomics, machine learning, and in vivo/in vitro experiments. Analyzing pan-cancer cohorts, the association between neoadjuvant chemotherapy/immunotherapy effectiveness and RNA methylation using single-cell sequencing was investigated. Multi-omics analysis and machine learning algorithms identified genomic variations, transcriptional dysregulation, and prognostic relevance of RMRs, revealing distinct molecular subtypes guiding pan-cancer neoadjuvant therapy stratification. Results: Our analysis unveiled a strong link between neoadjuvant therapy efficacy and RNA methylation dynamics, supported by pan-cancer single-cell sequencing data. Integration of omics data and machine learning algorithms identified RMR genomic variations, transcriptional dysregulation, and prognostic implications in pan-cancer. High-RMR-expressing tumors displayed increased genomic alterations, an immunosuppressive microenvironment, poorer prognosis, and resistance to neoadjuvant therapy. Molecular investigations and in vivo/in vitro experiments have substantiated that the JAK inhibitor TG-101,209 exerts notable effects on the immune microenvironment of tumors, rendering high-RMR-expressing pan-cancer tumors, particularly in pancreatic cancer, more susceptible to chemotherapy and immunotherapy. Conclusions: This study emphasizes the pivotal role of RMRs in pan-cancer neoadjuvant therapy, serving as predictive biomarkers for monitoring the tumor microenvironment, patient prognosis, and therapeutic response. Distinct molecular subtypes of RMRs aid individualized stratification in neoadjuvant therapy. Combining TG-101,209 adjuvant therapy presents a promising strategy to enhance the sensitivity of high-RMR-expressing tumors to chemotherapy and immunotherapy. However, further validation studies are necessary to fully understand the clinical utility of RNA methylation regulators and their impact on patient outcomes. [ABSTRACT FROM AUTHOR]

N6‐methyladenosine (m6A) is the most abundant epitranscriptomic mark that regulates the fate of RNA molecules. Recent studies have revealed a bidirectional interaction between m6A modification and the circadian clock. However, the precise temporal dynamics of m6A global enrichment in the central circadian pacemaker have not been fully elucidated. Our study investigates the relationship between FTO demethylase and molecular clocks in primary cells of the suprachiasmatic nucleus (SCN). In addition, we examined the effects of lipopolysaccharide (LPS) on Fto expression and the role of FTO in LPS‐induced reactive oxygen species (ROS) production in primary SCN cell culture. We observed circadian rhythmicity in the global m6A levels, which mirrored the rhythmic expression of the Fto demethylase. Silencing FTO using siRNA reduced the mesor of Per2 rhythmicity in SCN primary cells and extended the period of the PER2 rhythm in SCN primary cell cultures from PER2::LUC mice. When examining the immune response, we discovered that exposure to LPS upregulated global m6A levels while downregulating Fto expression in SCN primary cell cultures. Interestingly, we found a loss of circadian rhythmicity in Fto expression following LPS treatment, indicating that the decrease of FTO levels may contribute to m6A upregulation without directly regulating its circadian rhythm. To explore potential protective mechanisms against neurotoxic inflammation, we examined ROS production following LPS treatment in SCN primary cell cultures pretreated with FTO siRNA. We observed a time‐dependent pattern of ROS induction, with significant peak at 32 h but not at 20 h after synchronization. Silencing the FTO demethylase abolished ROS induction following LPS exposure, supporting the hypothesis that FTO downregulation serves as a protective mechanism during LPS‐induced neuroinflammation in SCN primary cell cultures. [ABSTRACT FROM AUTHOR]

While the significance of N6-methyladenosine (m6A) in viral regulation has been extensively studied, the functions of 5-methylcytosine (m5C) modification in viral biology remain largely unexplored. In this study, we demonstrate that m5C is more abundant than m6A in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and provide a comprehensive profile of the m5C landscape of SARS-CoV-2 RNA. Knockout of NSUN2 reduces m5C levels in SARS-CoV-2 virion RNA and enhances viral replication. Nsun2 deficiency mice exhibited higher viral burden and more severe lung tissue damages. Combined RNA-Bis-seq and m5C-MeRIP-seq identified the NSUN2-dependent m5C-methylated cytosines across the positive-sense genomic RNA of SARS-CoV-2, and the mutations of these cytosines enhance RNA stability. The progeny SARS-CoV-2 virions from Nsun2 deficiency mice with low levels of m5C modification exhibited a stronger replication ability. Overall, our findings uncover the vital role played by NSUN2-mediated m5C modification during SARS-CoV-2 replication and propose a host antiviral strategy via epitranscriptomic addition of m5C methylation to SARS-CoV-2 RNA. [ABSTRACT FROM AUTHOR]

Background: N6-methyladenosine (m6A) is the most common internal RNA modification and is involved in regulation of RNA and protein expression. AlkB family member 5 (ALKBH5) is a m6A demethylase. Given the important role of m6A in biological mechanisms, m6A and its regulators, have been implicated in many disease processes, including cancer. However, the contribution of ALKBH5 to invasive breast cancer (BC) remains poorly understood. The aim of this study was to evaluate the clinicopathological value of ALKBH5 in BC. Methods: Publicly available data were used to investigate ALKBH5 mRNA alterations, prognostic significance, and association with clinical parameters at the genomic and transcriptomic level. Differentially expressed genes (DEGs) and enriched pathways with low or high ALKBH5 expression were investigated. Immunohistochemistry (IHC) was used to assess ALKBH5 protein expression in a large well-characterised BC series (n = 1327) to determine the clinical significance and association of ALKBH5 expression. Results: Reduced ALKBH5 mRNA expression was significantly associated with poor prognosis and unfavourable clinical parameters. ALKBH5 gene harboured few mutations and/or copy number alternations, but low ALKBH5 mRNA expression was seen. Patients with low ALKBH5 mRNA expression had a number of differentially expressed genes and enriched pathways, including the cytokine-cytokine receptor interaction pathway. Low ALKBH5 protein expression was significantly associated with unfavourable clinical parameters associated with tumour progression including larger tumour size and worse Nottingham Prognostic Index group. Conclusion: This study implicates ALKBH5 in BC and highlights the need for further functional studies to decipher the role of ALKBH5 and RNA m6A methylation in BC progression. [ABSTRACT FROM AUTHOR]

Background: Long noncoding RNAs (lncRNAs) and N6-methyladenosine (m6A) modification of RNA play pivotal roles in tumorigenesis and cancer progression. However, knowledge regarding the expression patterns of m6A-related lncRNAs and their corresponding m6A regulators in prostate cancer (PCa) is limited. This study aimed to delineate the landscape of m6A-related lncRNAs, develop a predictive model, and identify the critical m6A regulators of prognostic lncRNAs in PCa. Methods: Clinical and transcriptome data of PCa patients were downloaded from The Cancer Genome Atlas (TCGA) database. Prognostic m6A-related lncRNAs were subsequently identified through Pearson correlation and univariate Cox regression analyses. The prognostic lncRNAs were clustered into two groups by consensus clustering analysis, and a risk signature model was constructed using least absolute shrinkage and selection operator (LASSO) regression analysis of the lncRNAs. This model was evaluated using survival, clinicopathological, and immunological analyses. Furthermore, based on the constructed lncRNA-m6A regulatory network and RT-qPCR results, RBM15 was identified as a critical regulator of m6A-related lncRNAs. The biological roles of RBM15 in PCa were explored through bioinformatics analysis and biological experiments. Results: Thirty-four prognostic m6A-related lncRNAs were identified and categorized into two clusters with different expression patterns and survival outcomes in PCa patients. Seven m6A lncRNAs (AC105345.1, AL354989.1, AC138028.4, AC022211.1, AC020558.2, AC004076.2, and LINC02666) were selected to construct a risk signature with robust predictive ability for overall survival and were correlated with clinicopathological characteristics and the immune microenvironment of PCa patients. Among them, LINC02666 and AC022211.1 were regulated by RBM15. In addition, RBM15 expression correlated with PCa progression, survival, and the immune response. Patients with elevated RBM15 expression were more susceptible to the drug AMG-232. Moreover, silencing RBM15 decreased the viability of PCa cells and promoted apoptosis. Conclusion: RBM15 is involved in the regulation of prognostic lncRNAs in the risk signature and has a robust predictive ability for PCa, making it a promising biomarker in PCa. [ABSTRACT FROM AUTHOR]