Unraveling the independent role of METTL3 in m6A modification and tumor progression in esophageal squamous cell carcinoma.

METTL3 and METTL14 are traditionally posited to assemble the m6A methyltransferase complex in a stoichiometric 1:1 ratio, modulating mRNA fate via m6A modifications. Nevertheless, recent investigations reveal inconsistent expression levels and prognostic significance of METTL3 and METTL14 across various tumor types, challenging their consistent functional engagement in neoplastic contexts. A pan-cancer analysis leveraging The Cancer Genome Atlas (TCGA) data has identified pronounced disparities in the expression patterns, functional roles, and correlations with tumor burden between METTL3 and METTL14, particularly in esophageal squamous cell carcinoma (ESCC). Knockdown experiments of METTL3 in EC109 cells markedly suppress cell proliferation both in vitro and in vivo, whereas METTL14 knockdown shows a comparatively muted effect on proliferation and does not significantly alter METTL3 protein levels. mRNA sequencing indicates that METTL3 singularly governs the expression of 1615 genes, with only 776 genes co-regulated with METTL14. Additionally, immunofluorescence co-localization studies suggest discrepancies in cellular localization between METTL3 and METTL14. High-performance liquid chromatography-mass spectrometry (HPLC-MS) analyses demonstrate that METTL3 uniquely associates with the Nop56p-linked pre-rRNA complex and mRNA splicing machinery, independent of METTL14. Preliminary bioinformatics and multi-omics investigations reveal that METTL3's autonomous role in modulating tumor cell proliferation and its involvement in mRNA splicing are potentially pivotal molecular mechanisms. Our study lays both experimental and theoretical groundwork for a deeper understanding of the m6A methyltransferase complex and the development of targeted tumor therapies focusing on METTL3.

Deciphering m6A methylation in monocyte-mediated cardiac fibrosis and monocyte-hitchhiked erythrocyte microvesicle biohybrid therapy.

Rationale: Device implantation frequently triggers cardiac remodeling and fibrosis, with monocyte-driven inflammatory responses precipitating arrhythmias. This study investigates the role of m6A modification enzymes METTL3 and METTL14 in these responses and explores a novel therapeutic strategy targeting these modifications to mitigate cardiac remodeling and fibrosis. Methods: Peripheral blood mononuclear cells (PBMCs) were collected from patients with ventricular septal defects (VSD) who developed conduction blocks post-occluder implantation. The expression of METTL3 and METTL14 in PBMCs was measured. METTL3 and METTL14 deficiencies were induced to evaluate their effect on angiotensin II (Ang II)-induced myocardial inflammation and fibrosis. m6A modifications were analyzed using methylated RNA immunoprecipitation followed by quantitative PCR. NF-κB pathway activity and levels of monocyte migration and fibrogenesis markers (CXCR2 and TGF-ß1) were assessed. An erythrocyte microvesicle-based nanomedicine delivery system was developed to target activated monocytes, utilizing the METTL3 inhibitor STM2457. Cardiac function was evaluated via echocardiography. Results: Significant upregulation of METTL3 and METTL14 was observed in PBMCs from patients with VSD occluder implantation-associated persistent conduction block. Deficiencies in METTL3 and METTL14 significantly reduced Ang II-induced myocardial inflammation and fibrosis by decreasing m6A modification on MyD88 and TGF-ß1 mRNAs. This disruption reduced NF-κB pathway activation, lowered CXCR2 and TGF-ß1 levels, attenuated monocyte migration and fibrogenesis, and alleviated cardiac remodeling. The erythrocyte microvesicle-based nanomedicine delivery system effectively targeted inflamed cardiac tissue, reducing inflammation and fibrosis and improving cardiac function. Conclusion: Inhibiting METTL3 and METTL14 in monocytes disrupts the NF-κB feedback loop, decreases monocyte migration and fibrogenesis, and improves cardiac function. Targeting m6A modifications of monocytes with STM2457, delivered via erythrocyte microvesicles, reduces inflammation and fibrosis, offering a promising therapeutic strategy for cardiac remodeling associated with device implantation.

[The Roles of N6-Methyladenosine Modification and Its Regulators in Male Reproduction]. / N6-ç”²åŸºè ºå˜Œå‘¤ä¿®é¥°åŠå ¶è°ƒæŽ§å› å­åœ¨ç”·æ€§ç”Ÿæ®–ä¸­çš„ä½œç”¨.

Infertility affects an estimated 10 to 15 percent of couples worldwide, with approximately half of the cases attributed to male-related issues. Most men diagnosed with infertility exhibit symptoms such as oligospermia, asthenospermia, azoospermia, and compromised sperm quality. Spermatogenesis is a complex and tightly coordinated process of germ cell differentiation, precisely regulated at transcriptional, posttranscriptional, and translational levels to ensure stage-specific gene expression during the development of spermatogenic cells and normal spermiogenesis. N6-methyladenosine (m6A) stands out as the most prevalent modification on eukaryotic mRNA, playing pivotal roles in various biological processes, including mRNA splicing, transportation, and translation. RNA methylation modification is a dynamic and reversible process primarily mediated by "writers", removed by "erasers", and recognized by "readers". In mammals, the aberrant methylation modification of m6A on mRNA is associated with a variety of diseases, including male infertility. However, the precise involvement of disrupted m6A modification in the pathogenesis of human male infertility remains unresolved. Intriguingly, a significant correlation has been found between the expression levels of m6A regulators in the testis and the severity of sperm concentration, motility, and morphology. Aberrant expression patterns of m6A regulatory proteins have been detected in anomalous human semen samples, including those of oligospermia, asthenozoospermia, and azoospermia. Furthermore, the examination of both sperm samples and testicular tissues revealed abnormal mRNA m6A modification, leading to reduced sperm motility and concentration in infertile men. Consequently, it is hypothesized that dysregulation of m6A modification might serve as an integral link in the mechanism of male infertility. This paper presents a comprehensive review of the recent discoveries regarding the spatial and temporal expression dynamics of m6A regulators in testicular tissues and the correlation between deregulated m6A regulators and human male infertility. Previous studies predominantly utilized constitutive or conditional knockout animal models for testicular phenotypic investigations. However, gene suppression in additional tissues could potentially influence the testis in constitutive knockout models. Furthermore, considering the compromised spermatogenesis observed in constitutive animals, distinguishing between the indirect effects of gene depletion on testicular development and its direct impact on the spermatogenic process is challenging, due to their intricate relationship. Such confounding factors might compromise the validity of the findings. To address this challenge, an inducible and conditional gene knockout model may serve as a superior approach. To date, nearly all reported studies have concentrated solely on the level changes of m6A and its regulators in germs cells, while the understanding of the function of m6A modification in testicular somatic cells remains limited. Testicular somatic cells, including peritubular myoid cells, Sertoli cells, and Leydig cells, play indispensable roles during spermatogenesis. Hence, comprehensive exploration of m6A modification within these cells as an additional crucial regulatory mechanism is warranted. In addition, exploration into the presence of unique methylation mechanisms or m6A regulatory factors within the testes is warranted. To elucidate the role of m6A modification in germ cells and testicular somatic cells, detailed experimental strategies need to be implemented. Among them, manipulation of the levels of key enzymes involved in m6A methylation and demethylation might be the most effective approach. Moreover, comprehensive analysis of the gene expression profiles involved in various signaling pathways, such as Wnt/ß-catenin, Ras/MAPK, and Hippo, in m6A-modified germ cells and testicular somatic cells can provide more insight into its regulatory role in the spermatogenesis process. Further research in this area could provide valuable insights for developing innovative strategies to treat male infertility. Finally, considering the mitigation impact of m6A imbalance regulation on disease, investigation concerning whether restoring the equilibrium of m6A modification regulation can restore normal spermatogenesis function is essential, potentially elucidating the pivotal clinical significance of m6A modulation in male infertility.

[Calcium Dibutyryl Adenosine Cyclophosphate Enhances the Effect of Metoprolol in Treating Older Adults With Heart Failure Combined With Arrhythmia]. / äºŒä¸é °çŽ¯ç£·è ºè‹·é’™å¯å¢žå¼ºç¾Žæ‰˜æ´›å°”å¯¹è€å¹´å¿ƒåŠ›è¡°ç«­åˆå¹¶å¿ƒå¾‹å¤±å¸¸æ‚£è€ çš„æ²»ç–—æ•ˆæžœ.

Objective: To explore the effect and safety of calcium dibutyryl adenosine cyclophosphate (dbcAMP-Ca) combined with metoprolol in the treatment of older adults with heart failure combined with arrhythmia. Methods: A total of 102 elderly patients with heart failure combined with arrhythmia were enrolled in our hospital between February 2021 and April 2023. The list of patients enrolled was entered into a random database by independent staffs not involved in the study and random assignment sequences were generated by the SAS9.4 software. Then, the 102 elderly patients were divided into a control group ( n=51) and an experimental group ( n=51). Patients in the control group were given metoprolol at an initial dose of 6.25 mg/d, which was gradually increased to the target dose of 25 mg/d. Patients in the experimental group were given 40 mg of dbcAMP-Ca once a day via intravenous drip in addition to the treatment given to the control group. Both groups were treated for 4 weeks. The rate of effective response to clinical treatment (the number of cases achieving significant effects and those achieving some effects divided by the total number of cases in the group) was defined as the main outcome index. Secondary indexes included cardiac function, heart rate variability, exercise ability, hemorheology, myocardial injury indexes, inflammatory indexes, and the occurrence of adverse reactions. Results: The rate of effective response to clinical treatment was higher in the experimental group than that in the control group (94.12% [48/51] vs. 78.43% [40/51], P<0.05). After treatment, the left ventricular end-diastolic and end-systolic dimensions (LVEDD and LVESD) and the interventricular septal thickness (IVS) were lower in the experimental group than those in the control group, while the left ventricular ejection fraction (LVEF) and the stroke volume (SV) were higher in the experimental group than those in the control group ( P<0.05). In terms of heart rate variability after treatment, the standard deviation of all the normal-to-normal intervals/the average of all the normal-to-normal intervals (SDNN/SDANN), the percentage of NN50 in the total number of normal-to-normal intervals (PNN50%), and the root mean square of the differences between adjacent normal-to-normal intervals/root mean square differences of successive R-R intervals (RMSSD) were higher in the experimental group than those in the control group ( P<0.05). In terms of exercise capacity after treatment, the subjects in the experimental group covered more distance in the 6-min walk test than those in the control group did ( P<0.05). In terms of the hemorheology indexes after treatment, the levels of platelet aggregation rate (PAgT), fibrinogen (FIB), erythrocyte sedimentation rate (ESR), and whole blood viscosity (ηb) were lower in the experimental group than those in the control group ( P<0.05). In terms of the myocardial injury indexes after treatment, the levels of serum N-terminal pro-brain natriuretic peptide (NT-pro BNP) and cardiac troponin I (cTnI) were lower in the experimental group than those in the control group, while the levels of insulin-like growth factor 1 (IGF-1) and cardiotrophin 1 (CT-1) were higher in the experimental group than those in the control group ( P<0.05). In terms of the inflammatory indexes after treatment, the levels of interleukin-6 (IL-6), high-sensitive C-reactive protein (hs-CRP), and tumor necrosis factor-α (TNF-α) were lower in the experimental group than those in the control group ( P<0.05). The incidence of adverse reactions in the experimental group (9.80%) and that in the control group (7.84%) were comparable ( P>0.05). Conclusion: The use of dbcAMP-Ca in addition to metoprolol can effectively improve cardiac function, heart rate variability, and exercise tolerance, while inhibiting inflammatory response in elderly patients with heart failure combined with arrhythmia, with high medication safety. The combination medication shows better safety and therapeutic effects than those of metoprolol used alone.

N6-methyladenosine modification of circMARK2 enhances cytoplasmic export and stabilizes LIN28B, contributing to the progression of Wilms tumor.

BACKGROUND: The potential involvement of circular RNAs (circRNAs) and N6-methyladenosine (m6A) modification in the progression of Wilms tumor (WT) has not been fully elucidated. This study investigates the regulatory mechanisms and clinical significance of m6A-modified circMARK2 and its role in WT progression. METHODS: We identified dysregulated circRNAs through deep sequencing and validated their expression by qRT-PCR in WT tissues. The biological functions of circMARK2 were assessed using clone formation, transwell migration, and orthotopic animal models. To dissect the underlying mechanisms, we employed RNA immunoprecipitation, RNA pull-down, dual-luciferase reporter assays, Western blotting, and immunofluorescence and immunohistochemical staining. RESULTS: CircMARK2, upregulated in WT tissues, was found to be m6A-modified and promoted cytoplasmic export. It facilitated WT progression by stabilizing LIN28B mRNA through the circMARK2/IGF2BP2 interaction. In vitro and in vivo studies demonstrated that circMARK2 enhances the malignant behavior of WT cells. Clinically, higher circMARK2 levels in tumor tissues of WT patients were linked to increased tumor aggressiveness and reduced survival rates. CONCLUSIONS: Our study provides the first comprehensive evidence that m6A-modified circMARK2 contributes to WT progression by enhancing LIN28B mRNA stability, promoting cellular aggressiveness. CircMARK2 emerges as a potential biomarker for prognosis and a promising target for therapeutic intervention in WT, underscoring the clinical relevance of m6A modification in pediatric renal cancer.

m6A- and m5C- modified lncRNAs orchestrate the prognosis in cutaneous melanoma and m6A- modified LINC00893 regulates cutaneous melanoma cell metastasis.

BACKGROUND: As the most important modifications on the RNA level, N6-methyladenosine (m6A-) and 5-methylcytosine (m5C-) modification could have a direct influence on the RNAs. Long non-coding RNAs (lncRNAs) could also be modified by methylcytosine modification. Compared with mRNAs, the function of lncRNAs could be more potent to some extent in biological processes like tumorigenesis. Until now, rare reports have been done associated with cutaneous melanoma. Herein, we wonder if the m6A- and m5C- modified lncRNAs could influence the immune landscape and prognosis in melanoma, and we also want to find some lncRNAs which could directly affect the malignant behaviors of melanoma. METHODS: Systematically, we explored the expression pattern of m6A- and m5C- modified lncRNAs in melanoma from datasets including UCSC Xena and NCBI GEO, and the prognostic lncRNAs were selected. Then, according to the expression pattern of lncRNAs, melanoma samples from these datasets were divided into several subtypes. Prognostic model, nomogram survival model, drug sensitivity, GO, and KEGG pathway analysis were performed. Furthermore, among several selected lncRNAs, we identified one lncRNA named LINC00893 and investigated its expression pattern and its biological function in melanoma cell lines. RESULTS: We identified 27 m6A- and m5C- related lncRNAs which were significantly associated with survival, and we made a subtype analysis of melanoma samples based on these 27 lncRNAs. Among the two subtypes, we found differences of immune cells infiltration between these two subtypes. Then, LASSO algorithm was used to screen the optimized lncRNAs combination including ZNF252P-AS1, MIAT, FAM13A-AS1, LINC-PINT, LINC00893, AGAP2-AS1, OIP5-AS1, and SEMA6A-AS1. We also found that there was a significant correlation between the different risk groups predicted based on RS model and the actual prognosis. The nomogram survival model based on independent survival prognostic factors was also constructed. Besides, sensitivity to chemotherapeutic agents, GO and KEGG analysis were performed. In different risk groups, a total of 14 drug molecules with different distributions were obtained, which included AZD6482, AZD7762, AZD8055, camptothecin, dasatinib, erlotinib, gefitinib, gemcitabine, GSK269962A, nilotinib, rapamycin, and sorafenib. A total of 55 significantly related biological processes and 17 KEGG signaling pathways were screened. At last, we noticed that LINC00893 had a relatively lower expression in melanoma tissue and cell lines compared with adjacent tissues and epidermal melanocyte, and down-regulation of LINC00893 could promote the malignant behavior of melanoma cells in A875 and MV3. In these two melanoma cell lines, down-regulation of m6A-related molecules like YTHDF3 and METTL3 could promote the expression of LINC00893. CONCLUSION: We made an analysis of m6A- and m5C- related lncRNAs in melanoma samples and a prediction of these lncRNAs' role in prognosis, tumor microenvironment, immune infiltration, and clinicopathological features. We also found that LINC00893, which is potentially regulated by m6A modification, could serve as a tumor-suppressor in melanoma and play an inhibitory role in melanoma metastasis.

M6A modification and T cells in adipose tissue inflammation.

Adipose tissue in the obese state can lead to low-grade chronic inflammation while inducing or exacerbating obesity-related metabolic diseases and impairing overall health.T cells, which are essential immune cells similar to macrophages, are widely distributed in adipose tissue and perform their immunomodulatory function; they also cross-talk with other cells in the vascular stromal fraction. Based on a large number of studies, it has been found that N6 methyl adenine (m6A) is one of the most representative of epigenetic modifications, which affects the crosstalk between T cells, as well as other immune cells, in several ways and plays an important role in the development of adipose tissue inflammation and related metabolic diseases. In this review, we first provide an overview of the widespread presence of T cells in adipose tissue and summarize the key role of T cells in adipose tissue inflammation. Next, we explored the effects of m6A modifications on T cells in adipose tissue from the perspective of adipose tissue inflammation. Finally, we discuss the impact of m6a-regulated crosstalk between T cells and immune cells on the prospects for improving adipose tissue inflammation research, providing additional new ideas for the treatment of obesity.

ADAR-Mediated A>I(G) RNA Editing in the Genotoxic Drug Response of Breast Cancer.

Epitranscriptomics is a field that delves into post-transcriptional changes. Among these modifications, the conversion of adenosine to inosine, traduced as guanosine (A>I(G)), is one of the known RNA-editing mechanisms, catalyzed by ADARs. This type of RNA editing is the most common type of editing in mammals and contributes to biological diversity. Disruption in the A>I(G) RNA-editing balance has been linked to diseases, including several types of cancer. Drug resistance in patients with cancer represents a significant public health concern, contributing to increased mortality rates resulting from therapy non-responsiveness and disease progression, representing the greatest challenge for researchers in this field. The A>I(G) RNA editing is involved in several mechanisms over the immunotherapy and genotoxic drug response and drug resistance. This review investigates the relationship between ADAR1 and specific A>I(G) RNA-edited sites, focusing particularly on breast cancer, and the impact of these sites on DNA damage repair and the immune response over anti-cancer therapy. We address the underlying mechanisms, bioinformatics, and in vitro strategies for the identification and validation of A>I(G) RNA-edited sites. We gathered databases related to A>I(G) RNA editing and cancer and discussed the potential clinical and research implications of understanding A>I(G) RNA-editing patterns. Understanding the intricate role of ADAR1-mediated A>I(G) RNA editing in breast cancer holds significant promise for the development of personalized treatment approaches tailored to individual patients' A>I(G) RNA-editing profiles.

Elevated WTAP promotes hyperinflammation by increasing m6A modification in inflammatory disease models.

Emerging evidence has linked the dysregulation of N6-methyladenosine (m6A) modification to inflammation and inflammatory diseases, but the underlying mechanism still needs investigation. Here, we found that high levels of m6A modification in a variety of hyperinflammatory states are p65-dependent because Wilms tumor 1-associated protein (WTAP), a key component of the "writer" complex, is transcriptionally regulated by p65, and its overexpression can lead to increased levels of m6A modification. Mechanistically, upregulated WTAP is more prone to phase separation to facilitate the aggregation of the writer complex to nuclear speckles and the deposition of m6A marks on transcriptionally active inflammatory transcripts, thereby accelerating the proinflammatory response. Further, a myeloid deficiency in WTAP attenuates the severity of LPS-induced sepsis and DSS-induced IBD. Thus, the proinflammatory effect of WTAP is a general risk-increasing mechanism, and interrupting the assembly of the m6A writer complex to reduce the global m6A levels by targeting the phase separation of WTAP may be a potential and promising therapeutic strategy for alleviating hyperinflammation.

Identification of differential m6A RNA methylomes and ALKBH5 as a potential prevention target in the developmental neurotoxicity induced by multiple sevoflurane exposures.

Sevoflurane, as a commonly used inhaled anesthetic for pediatric patients, has been reported that multiple sevoflurane exposures are associated with a greater risk of developing neurocognitive disorder. N6-Methyladenosine (m6A), as the most common mRNA modification in eukaryotes, has emerged as a crucial regulator of brain function in processes involving synaptic plasticity, learning and memory, and neurodevelopment. Nevertheless, the relevance of m6A RNA methylation in the multiple sevoflurane exposure-induced developmental neurotoxicity remains mostly elusive. Herein, we evaluated the genome-wide m6A RNA modification and gene expression in hippocampus of mice that received with multiple sevoflurane exposures using m6A-sequencing (m6A-seq) and RNA-sequencing (RNA-seq). We discovered 19 genes with differences in the m6A methylated modification and differential expression in the hippocampus. Among these genes, we determined that a total of nine differential expressed genes may be closely associated with the occurrence of developmental neurotoxicity induced by multiple sevoflurane exposures. We further found that the alkB homolog 5 (ALKBH5), but not methyltransferase-like 3 (METTL3) and Wilms tumor 1-associated protein (WTAP), were increased in the hippocampus of mice that received with multiple sevoflurane exposures. And the IOX1, as an inhibitor of ALKBH5, significantly improved the learning and memory defects and reduced neuronal damage in the hippocampus of mice induced by multiple sevoflurane exposures. The current study revealed the role of m6A methylated modification and m6A-related regulators in sevoflurane-induced cognitive impairment, which might provide a novel insight into identifying biomarkers and therapeutic strategies for inhaled anesthetic-induced developmental neurotoxicity.

Unlocking the adenosine receptor mechanism of the tumour immune microenvironment.

The suppressive tumour microenvironment significantly hinders the efficacy of immunotherapy in treating solid tumors. In this context, stromal cells, such as tumour-associated fibroblasts, undergo changes that include an increase in the number and function of immunosuppressive cells. Adenosine, a factor that promotes tumour growth, is produced from ATP breakdown and is markedly elevated in the tumour microenvironment. It acts through specific binding to adenosine receptors, with A2A and A2B adenosine receptor being primary drivers of immunosuppression. This paper presents the roles of various adenosine receptors in different tumour microenvironments. This review focus on the function of adenosine receptors in the stromal cells and non-cellular components of the tumour microenvironment. Additionally, we summarize and discuss recent advances and potential trends in using adenosine receptor antagonists combined with immunotherapy.

Inhibition of Vascular Smooth Muscle Cell Proliferation by ENPP1: The Role of CD73 and the Adenosine Signaling Axis.

The Ectonucleotide Pyrophosphatase/Phosphodiesterase 1 (ENPP1) ectoenzyme regulates vascular intimal proliferation and mineralization of bone and soft tissues. ENPP1 variants cause Generalized Arterial Calcification of Infancy (GACI), a rare genetic disorder characterized by ectopic calcification, intimal proliferation, and stenosis of large- and medium-sized arteries. ENPP1 hydrolyzes extracellular ATP to pyrophosphate (PPi) and AMP. AMP is the precursor of adenosine, which has been implicated in the control of neointimal formation. Herein, we demonstrate that an ENPP1-Fc recombinant therapeutic inhibits proliferation of vascular smooth muscle cells (VSMCs) in vitro and in vivo. Addition of ENPP1 and ATP to cultured VSMCs generated AMP, which was metabolized to adenosine. It also significantly decreased cell proliferation. AMP or adenosine alone inhibited VSMC growth. Inhibition of ecto-5'-nucleotidase CD73 decreased adenosine accumulation and suppressed the anti-proliferative effects of ENPP1/ATP. Addition of AMP increased cAMP synthesis and phosphorylation of VASP at Ser157. This AMP-mediated cAMP increase was abrogated by CD73 inhibitors or by A2aR and A2bR antagonists. Ligation of the carotid artery promoted neointimal hyperplasia in wild-type mice, which was exacerbated in ENPP1-deficient ttw/ttw mice. Prophylactic or therapeutic treatments with ENPP1 significantly reduced intimal hyperplasia not only in ttw/ttw but also in wild-type mice. These findings provide the first insight into the mechanism of the anti-proliferative effect of ENPP1 and broaden its potential therapeutic applications beyond enzyme replacement therapy.

The m6A-ncRNAs axis in diabetes complications: novel mechanism and therapeutic potential.

Diabetes, a multifaceted metabolic disorder, poses a significant global health burden with its increasing prevalence and associated complications, such as diabetic nephropathy, diabetic retinopathy, diabetic cardiomyopathy, and diabetic angiopathy. Recent studies have highlighted the intricate interplay between N6-methyladenosine (m6A) and non-coding RNAs (ncRNAs) in key pathways implicated in these diabetes complications, like cell apoptosis, oxidative stress, and inflammation. Thus, understanding the mechanistic insights into how m6A dysregulation impacts the expression and function of ncRNAs opens new avenues for therapeutic interventions targeting the m6A-ncRNAs axis in diabetes complications. This review explores the regulatory roles of m6A modifications and ncRNAs, and stresses the role of the m6A-ncRNA axis in diabetes complications, providing a therapeutic potential for these diseases.

Characterization of m6A Modifiers and RNA Modifications in Uterine Fibroids.

Uterine leiomyoma or fibroids are prevalent noncancerous tumors of the uterine muscle layer, yet their origin and development remain poorly understood. We analyzed RNA expression profiles of 15 epigenetic mediators in uterine fibroids compared to myometrium using publicly available RNA sequencing (RNA-seq) data. To validate our findings, we performed RT-qPCR on a separate cohort of uterine fibroids targeting these modifiers confirming our RNA-seq data. We then examined protein profiles of key N6-methyladenosine (m6A) modifiers in fibroids and their matched myometrium, showing no significant differences in concordance with our RNA expression profiles. To determine RNA modification abundance, mRNA and small RNA from fibroids and matched myometrium were analyzed by ultra-high performance liquid chromatography-mass spectrometry identifying prevalent m6A and 11 other known modifiers. However, no aberrant expression in fibroids was detected. We then mined a previously published dataset and identified differential expression of m6A modifiers that were specific to fibroid genetic subtype. Our analysis also identified m6A consensus motifs on genes previously identified to be dysregulated in uterine fibroids. Overall, using state-of-the-art mass spectrometry, RNA expression, and protein profiles, we characterized and identified differentially expressed m6A modifiers in relation to driver mutations. Despite the use of several different approaches, we identified limited differential expression of RNA modifiers and associated modifications in uterine fibroids. However, considering the highly heterogenous genomic and cellular nature of fibroids, and the possible contribution of single molecule m6A modifications to fibroid pathology, there is a need for greater in-depth characterization of m6A marks and modifiers in a larger and diverse patient cohort.

METTL14 promotes lipid metabolism reprogramming and sustains nasopharyngeal carcinoma progression via enhancing m6A modification of ANKRD22 mRNA.

BACKGROUND: N6-methyladenosine (m6A) modification is essential for modulating RNA processing as well as expression, particularly in the context of malignant tumour progression. However, the exploration of m6A modification in nasopharyngeal carcinoma (NPC) remains very limited. METHODS: RNA m6A levels were analysed in NPC using m6A dot blot assay. The expression level of methyltransferase-like 14 (METTL14) within NPC tissues was analysed from public databases as well as RT-qPCR and immunohistochemistry. The influences on METTL14 expression on NPC proliferation and metastasis were explored via in vitro as well as in vivo functional assays. Targeted genes of METTL14 were screened using the m6A and gene expression profiling microarray data. Actinomycin D treatment and polysome analysis were used to detect the half-life and translational efficiency of ANKRD22. Flow cytometry, immunofluorescence and immunoprecipitation were used to validate the role of ANKRD22 on lipid metabolism in NPC cells. ChIP-qPCR analysis of H3K27AC signalling near the promoters of METTL14, GINS3, POLE2, PLEK2 and FERMT1 genes. RESULTS: We revealed METTL14, in NPC, correlating with poor patient prognosis. In vitro and in vivo assays indicated METTL14 actively promoted NPC cells proliferation and metastasis. METTL14 catalysed m6A modification on ANKRD22 messenger ribonucleic acid (mRNA), recognized by the reader IGF2BP2, leading to increased mRNA stability and higher translational efficiency. Moreover, ANKRD22, a metabolism-related protein on mitochondria, interacted with SLC25A1 to enhance citrate transport, elevating intracellular acetyl-CoA content. This dual impact of ANKRD22 promoted lipid metabolism reprogramming and cellular lipid synthesis while upregulating the expression of genes associated with the cell cycle (GINS3 and POLE2) and the cytoskeleton (PLEK2 and FERMT1) through heightened epigenetic histone acetylation levels in the nucleus. Intriguingly, our findings highlighted elevated ANKRD22-mediated histone H3 lysine 27 acetylation (H3K27AC) signals near the METTL14 promoter, which contributes to a positive feedback loop perpetuating malignant progression in NPC. CONCLUSIONS: The identified METTL14-ANKRD22-SLC25A1 axis emerges as a promising therapeutic target for NPC, and also these molecules may serve as novel diagnostic biomarkers.

Silencing of FTO inhibits oxidative stress to relieve neuropathic pain by m6A modification of GPR177.

BACKGROUND: Neuropathic pain (NP) is a challenging health condition owing to its complex nature and associated multiple etiologies. The occurrence of NP involves the abnormal activity of neurons mediated by oxidative stress (OS). Previous research has demonstrated that m6A methylation plays a role in the regulatory pathway of NP. This study aimed to investigate the specific molecular pathways through which m6A methylation modifiers alleviate NP. METHODS: For this purpose, an NO rat model was developed via spared nerve injury (SNI), followed by quantifying the animal's pain assessment via paw withdrawal threshold (PWT) and paw withdrawal latency (PWL). The OS in SNI rats was evaluated by measuring reactive oxygen species, superoxide dismutase, and catalase (CAT) in spinal cord tissues. Moreover, quantitative-real-time polymerase chain reaction and western blot analysis were employed for detecting fat mass and obesity-associated (FTO) and GPR177 levels, while m6A levels of GPR117 were analyzed via MeRIP. RESULTS: The results indicated an enhanced OS with highly expressed FTO in spinal cord tissue samples, where knocking down Fto effectively relieved NP and OS in SNI rats. Mechanistic investigations revealed that Fto-mediated reduction of Grp177 m6A modification was involved in the WNT5a/TRPV1 axis-mediated OS remission of NP. Moreover, in vitro experiment results indicated that YTHDF2 was an important m6A methylated reading protein for this process. CONCLUSIONS: Fto silencing leads to increased m6A methylation of Grp177 through a YTHDF2-dependent mechanism, resulting in decreased Grp177 stability and ultimately reducing NP in rats by OS suppression.

m6A-dependent mature miR-151-5p accelerates the malignant process of HNSCC by targeting LYPD3.

miRNA has emerged as a crucial regulator in various of pathological and physiological processes, yet its precise mechanism of action the detailed mechanism of their action in Head and neck squamous cell carcinoma (HNSCC) remains incompletely understood. This study sheds light on the role of mi-151-5p, revealing its significantly elevated expression in tumor cells, which notably enhances the invasion and migration of HNSCC cells. This effect is achieved through directly targeting LY6/PLAUR Domain Containing 3 (LYPD3) by miR-151-5p, involving complementary binding to the 3'-untranslated regions (3'-UTR) in the mRNA of LYPD3. Consequently, this interaction accelerates the metastasis of HNSCC. Notably, clinical observations indicate a correlation between high expression of miR-151-5p and low levels of LYPD3 in clinical settings are correlated with poor prognosis of HNSCC patients. Furthermore, our investigation demonstrates that glycosylation of LYPD3 modulates its subcellular localization and reinforces its role in suppressing HNSCC metastasis. Additionally, we uncover a potential regulatory mechanism involving the facilitation of miR-151-5p maturation and accumulation through N6-methyladenosine (m6A) modification. This process is orchestrated by methyltransferase-like 3 (METTL3) and mediated by a newly identified reader, heterogeneous nuclear ribonucleoprotein U (hnRNP U). These findings collectively underscore the significance of the METTL3/miR-151-5p/LYPD3 axis serves as a prominent driver in the malignant progression of HNSCC.

METTL3-m6A methylation inhibits the proliferation and viability of type II alveolar epithelial cells in acute lung injury by enhancing the stability and translation efficiency of Pten mRNA.

BACKGROUND: The pathogenesis of acute lung injury (ALI) involves a severe inflammatory response, leading to significant morbidity and mortality. N6-methylation of adenosine (m6A), an abundant mRNA nucleotide modification, plays a crucial role in regulating mRNA metabolism and function. However, the precise impact of m6A modifications on the progression of ALI remains elusive. METHODS: ALI models were induced by either intraperitoneal injection of lipopolysaccharide (LPS) into C57BL/6 mice or the LPS-treated alveolar type II epithelial cells (AECII) in vitro. The viability and proliferation of AECII were assessed using CCK-8 and EdU assays. The whole-body plethysmography was used to record the general respiratory functions. M6A RNA methylation level of AECII after LPS insults was detected, and then the "writer" of m6A modifications was screened. Afterwards, we successfully identified the targets that underwent m6A methylation mediated by METTL3, a methyltransferase-like enzyme. Last, we evaluated the regulatory role of METTL3-medited m6A methylation at phosphatase and tensin homolog (Pten) in ALI, by assessing the proliferation, viability and inflammation of AECII. RESULTS: LPS induced marked damages in respiratory functions and cellular injuries of AECII. The m6A modification level in mRNA and the expression of METTL3, an m6A methyltransferase, exhibited a notable rise in both lung tissues of ALI mice and cultured AECII cells subjected to LPS treatment. METTL3 knockdown or inhibition improved the viability and proliferation of LPS-treated AECII, and also reduced the m6A modification level. In addition, the stability and translation of Pten mRNA were enhanced by METTL3-mediated m6A modification, and over-expression of PTEN reversed the protective effect of METTL3 knockdown in the LPS-treated AECII. CONCLUSIONS: The progression of ALI can be attributed to the elevated levels of METTL3 in AECII, as it promotes the stability and translation of Pten mRNA through m6A modification. This suggests that targeting METTL3 could offer a novel approach for treating ALI.

Comprehensive landscape of m6A regulator-related gene patterns and tumor microenvironment infiltration characterization in gastric cancer.

The epigenetic regulation of N6-methyladenosine (m6A) has attracted considerable interest in tumor research, but the potential roles of m6A regulator-related genes, remain largely unknown within the context of gastric cancer (GC) and tumor microenvironment (TME). Here, a comprehensive strategy of data mining and computational biology utilizing multiple datasets based on 28 m6A regulators (including novel anti-readers) was employed to identify m6A regulator-related genes and patterns and elucidate their underlying mechanisms in GC. Subsequently, a scoring system was constructed to evaluate individual prognosis and immunotherapy response. Three distinct m6A regulator-related patterns were identified through the unsupervised clustering of 56 m6A regulator-related genes (all significantly associated with GC prognosis). TME characterization revealed that these patterns highly corresponded to immune-inflamed, immune-excluded, and immune-desert phenotypes, and their TME characteristics were highly consistent with different clinical outcomes and biological processes. Additionally, an m6A-related scoring system was developed to quantify the m6A modification pattern of individual samples. Low scores indicated high survival rates and high levels of immune activation, whereas high scores indicated stromal activation and tumor malignancy. Furthermore, the m6A-related scores were correlated with tumor mutation loads and various clinical traits, including molecular or histological subtypes and clinical stage or grade, and the score had predictive values across all digestive system tumors and even in all tumor types. Notably, a low score was linked to improved responses to anti-PD-1/L1 and anti-CTLA4 immunotherapy in three independent cohorts. This study has expanded the important role of m6A regulator-related genes in shaping TME diversity and clinical/biological traits of GC. The developed scoring system could help develop more effective immunotherapy strategies and personalized treatment guidance.

Construction of m6A-Related Gene Prediction Model and Subtype Analysis in Non-Obstructive Azoospermia Based on Bioinformatics.

PURPOSE: Non-obstructive azoospermia (NOA) is a severe and common cause of male infertility. Currently, the most reliable predictor of sperm retrieval success in NOA is histopathology, but preoperative testicular biopsy often increases the difficulty of sperm retrieval surgery. This study aims to explore the characteristics of N6-methyladenosine (m6A) modification in NOA patients and investigate the potential biomarkers and molecular mechanisms for pathological diagnosis and treatment of NOA using m6A-related genes. METHODS: NOA-related datasets were downloaded from the GEO database. Based on the results of LASSO regression analysis, a prediction model was established from differentially expressed m6A-related genes, and the predictive performance of the model was evaluated using ROC curves. Cluster analysis was performed based on differentially expressed m6A-related genes to evaluate the differences in different m6A modification patterns in terms of differentially expressed genes (DEGs), biological features, and immune features. RESULTS: There were significant differences in eight m6A-related genes between NOA samples and healthy controls. The ROC curves showed excellent predictive performance for the diagnostic models constructed with ALKBH5 and FTO. DEGs of two m6A modification subtypes indicated the influence of m6A-related genes in the biological processes of mitosis and meiosis in NOA patients, and there were significant immune differences between the two subtypes. CONCLUSION: The NOA pathological diagnostic models constructed with FTO and ALKBH5 have good predictive ability. We have identified two different m6A modification subtypes, which may help predict sperm retrieval success rate and treatment selection in NOA patients.