New insights into developmental biology of Eimeria tenella revealed by comparative analysis of mRNA N6-methyladenosine modification between unsporulated oocysts and sporulated oocysts

Evidence showed that N6-methyladenosine(m^(6)A)modification plays a pivotal role in influencing RNA fate and is strongly associated with cell growth and developmental processes in many species.However,no information regarding m^(6)A modification in Eimeria tenella is currently available.In the present study,we surveyed the transcriptome-wide prevalence of m^(6)A in sporulated oocysts and unsporulated oocysts of E.tenella.Methylated RNA immunoprecipitation sequencing(MeRIP-seq)analysis showed that m^(6)A modification was most abundant in the coding sequences,followed by stop codon.There were 3,903 hypermethylated and 3,178 hypomethylated mRNAs in sporulated oocysts compared with unsporulated oocysts.Further joint analysis suggested that m^(6)A modification of the majority of genes was positively correlated with mRNA expression.The mRNA relative expression and m^(6)A level of the selected genes were confirmed by quantitative reverse transcription PCR(RT-qPCR)and MeRIP-qPCR.GO and KEGG analysis indicated that differentially m^(6)A methylated genes(DMMGs)with significant differences in mRNA expression were closely related to processes such as regulation of gene expression,epigenetic,microtubule,autophagy-other and TOR signaling.Moreover,a total of 96 DMMGs without significant differences in mRNA expression showed significant differences at protein level.GO and pathway enrichment analysis of the 96 genes showed that RNA methylation may be involved in cell biosynthesis and metabolism of E.tenella.We firstly present a map of RNA m^(6)A modification in E.tenella,which provides significant insights into developmental biology of E.tenella.

RNA modification by M6A methylation in cardiovascular diseases: Current trends and future directions

N6-methyladenosine(M6A)is the most common modification in eukaryotic RNAs for the regulation of RNA transcription,processing,splicing,degradation,and translation.RNA modification by M6A is dynamically reversible,involving methylated transferase,demethylase,and methylated reading protein.M6A-mediated gene regulation involves cell differentiation,metastasis,apoptosis,and proliferation.Dysregulation of M6A can lead to various diseases.Cardiovascular disease(CVD)seriously endangers human health and brings great social burden.Seeking effective prevention and treatment strategies for CVD is a challenge to both fundamentalists and clinicians.Substantial evidence has suggested the key role of M6A modification in the development of CVDs.This review summarizes the mechanism of M6A RNA modification and the latest research progress in respect with its role in CVDs,including atherosclerosis,coronary artery disease,myocardial infarction and cardiac remodeling,myocardial ischemia-reperfusion injury,heart failure,hypertension,and aortic aneurysm,and the potential applications of the findings to CVDs,thereby providing new ideas and approaches for the diagnosis and therapy of CVDs.

Aberrant expression of enzymes regulating m^6A mRNA methylation: implication in cancer

N^6-methyladenosine(m^6 A) is an essential RNA modification that regulates key cellular processes, including stem cell renewal,cellular differentiation, and response to DNA damage. Unsurprisingly, aberrant m^6 A methylation has been implicated in the development and maintenance of diverse human cancers. Altered m^6 A levels affect RNA processing, mRNA degradation, and translation of mRNAs into proteins, thereby disrupting gene expression regulation and promoting tumorigenesis. Recent studies have reported that the abnormal expression of m^6 A regulatory enzymes affects m^6 A abundance and consequently dysregulates the expression of tumor suppressor genes and oncogenes, including MYC, SOCS2, ADAM19, and PTEN. In this review, we discuss the specific roles of m^6 A missing space "writers", "erasers", and "readers" in normal physiology and how their altered expression promotes tumorigenesis. We also describe the potential of exploiting the aberrant expression of these enzymes for cancer diagnosis, prognosis, and the development of novel therapies.

METTL3-mediated m^(6)A RNA methylation regulates dorsal lingual epithelium homeostasis

The dorsal lingual epithelium,which is composed of taste buds and keratinocytes differentiated from K14^(+)basal cells,discriminates taste compounds and maintains the epithelial barrier.N6-methyladenosine(m^(6)A)is the most abundant mRNA modification in eukaryotic cells.How METTL3-mediated m^(6)A modification regulates K14^(+)basal cell fate during dorsal lingual epithelium formation and regeneration remains unclear.Here we show knockout of Mettl3 in K14^(+)cells reduced the taste buds and enhanced keratinocytes.Deletion of Mettl3 led to increased basal cell proliferation and decreased cell division in taste buds.Conditional Mettl3 knock-in mice showed little impact on taste buds or keratinization,but displayed increased proliferation of cells around taste buds in a protective manner during post-irradiation recovery.Mechanically,we revealed that the most frequent m^(6)A modifications were enriched in Hippo and Wnt signaling,and specific peaks were observed near the stop codons of Lats1 and FZD7.Our study elucidates that METTL3 is essential for taste bud formation and could promote the quantity recovery of taste bud after radiation.

Lipid metabolism and m^(6)A RNA methylation are altered in lambs supplemented rumen-protected methionine and lysine in a low-protein diet

Background:Methionine or lysine has been reported to influence DNA methylation and fat metabolism,but their combined effects in N6-methyl-adenosine(m^(6)A)RNA methylation remain unclarified.The combined effects of rumen-protected methionine and lysine(RML)in a low-protein(LP)diet on lipid metabolism,m^(6)A RNA methylation,and fatty acid(FA)profiles in the liver and muscle of lambs were investigated.Sixty-three male lambs were divided into three treatment groups,three pens per group and seven lambs per pen.The lambs were fed a 14.5%crude protein(CP)diet(adequate protein[NP]),12.5%CP diet(LP),and a LP diet plus RML(LP+RML)for 60 d.Results:The results showed that the addition of RML in a LP diet tended to lower the concentrations of plasma leptin(P=0.07),triglyceride(P=0.05),and non-esterified FA(P=0.08).Feeding a LP diet increased the enzyme activity or m RNA expression of lipogenic enzymes and decreased lipolytic enzymes compared with the NP diet.This effect was reversed by supplementation of RML with a LP diet.The inclusion of RML in a LP diet affected the polyunsaturated fatty acids(PUFA),n-3 PUFA,and n-6 PUFA in the liver but not in the muscle,which might be linked with altered expression of FA desaturase-1(FADS1)and acetyl-Co A carboxylase(ACC).A LP diet supplemented with RML increased(P<0.05)total m^(6)A levels in the liver and muscle and were accompanied by decreased expression of fat mass and obesity-associated protein(FTO)and alk B homologue 5(ALKBH5).The m RNA expressions of methyltransferase-like 3(METTL3)and methyltransferase-like 14(METTL14)in the LP+RML diet group were lower than those in the other two groups.Supplementation of RML with a LP diet affected only liver YTH domain family(YTHDF2)proteins(P<0.05)and muscle YTHDF3(P=0.09),which can be explained by limited m^(6)Abinding proteins that were mediated in m RNA fate.Conclusions:Our findings showed that the inclusion of RML in a LP diet could alter fat deposition through modulations of lipogenesis and lipolysis in the liver and muscle.These changes in fat metabolism may be associated with the modification of m^(6)A RNA methylation.

Dysregulation of RNA modification systems in clinical populations with neurocognitive disorders

The study of modified RNA known as epitranscriptomics has become increasingly relevant in our understanding of disease-modifying mechanisms.Methylation of N6 adenosine(m^(6)A)and C5 cytosine(m^(5)C)bases occur on mRNAs,tRNA,mt-tRNA,and rRNA species as well as non-coding RNAs.With emerging knowledge of RNA binding proteins that act as writer,reader,and eraser effector proteins,comes a new understanding of physiological processes controlled by these systems.Such processes when spatiotemporally disrupted within cellular nanodomains in highly specialized tissues such as the brain,give rise to different forms of disease.In this review,we discuss accumulating evidence that changes in the m^(6)A and m^(5)C methylation systems contribute to neurocognitive disorders.Early studies first identified mutations within FMR1 to cause intellectual disability Fragile X syndromes several years before FMR1 was identified as an m^(6)A RNA reader protein.Subsequently,familial mutations within the m^(6)A writer gene METTL5,m^(5)C writer genes NSUN2,NSUN3,NSUN5,and NSUN6,as well as THOC2 and THOC6 that form a protein complex with the m^(5)C reader protein ALYREF,were recognized to cause intellectual development disorders.Similarly,differences in expression of the m^(5)C writer and reader effector proteins,NSUN6,NSUN7,and ALYREF in brain tissue are indicated in individuals with Alzheimer's disease,individuals with a high neuropathological load or have suffered traumatic brain injury.Likewise,an abundance of m^(6)A reader and anti-reader proteins are reported to change across brain regions in Lewy bodies diseases,Alzheimer's disease,and individuals with high cognitive reserve.m^(6)A-modified RNAs are also reported significantly more abundant in dementia with Lewy bodies brain tissue but significantly reduced in Parkinson's disease tissue,whilst modified RNAs are misplaced within diseased cells,particularly where synapses are located.In parahippocampal brain tissue,m^(6)A modification is enriched in transcripts associated with psychiatric disorders including conditions with clear cognitive deficits.These findings indicate a diverse set of molecular mechanisms are influenced by RNA methylation systems that can cause neuronal and synaptic dysfunction underlying neurocognitive disorders.Targeting these RNA modification systems brings new prospects for neural regenerative therapies.

Regulations of m^(6)A methylation on tomato fruit chilling injury

Tomato fruit are sensitive to chilling injury(CI)during cold storage.Several factors have been discovered to be involved in chilling injury of tomato fruit.Plant hormones play an important regulatory role,however,the relationship between chilling injury and N6-methyladenosine(m^(6)A)methylation of transcripts in plant hormone pathways has not been reported yet.In order to clarify the complex regulatory mechanism of m^(6)A methylation on chilling injury in tomato fruit,Nanopore direct RNA sequencing was employed.A large number of enzymes and transcription factors were found to be involved in the regulation process of fruit chilling injury,which were associated with plant hormone,such as 1-aminocyclopropane 1-carboxylate synthase(ACS),aspartate aminotransferase(AST),auxin response factor(ARF2),ethylene response factor 2(ERF2),gibberellin 20-oxidase-3(GA20ox)and jasmonic acid(JA).By conjoint analysis of the differential expression transcripts related to chilling injury andm^(6)Amethylation differential expression transcripts 41 differential expression transcripts were identified involved in chilling injury including 1-aminocyclopropane-1-carboxylate oxidase(ACO)and pectinesterase(PE)were down-regulated and heat shock cognate 70 kD protein 2(cpHSC70),HSP70-binding protein(HspBP)and salicylic acid-binding protein 2(SABP2)were up-regulated.Our results will provide a deeper understanding for chilling injury regulatory mechanism and post-harvest cold storage of tomato fruit.

m^(6)A修饰对药物代谢酶和药物转运体的调控作用

m^(6)A修饰是RNA甲基化修饰中最丰富的一种修饰,受甲基转移酶和去甲基化酶的动态调控,被m^(6)A识别蛋白识别并结合后可影响mRNA的剪切、稳定性和翻译等生物学过程来调控靶基因的表达。最近的研究发现,m^(6)A修饰可通过多种途径来调控药物代谢酶和药物转运体表达,进而影响机体对药物的代谢速率或影响细胞中的药物浓度,最终导致药物治疗效果发生变化。该文综述了m^(6)A修饰调控药物代谢酶和药物转运体分子机制的研究进展,以期为临床上的合理用药、个体化用药提供新思路。

m^6A RNA甲基化在非小细胞肺癌中的研究进展

m^6A修饰是真核生物mRNA中最丰富的修饰之一,该过程受m^6A甲基转移酶和去甲基化酶的共同调控。m^6A修饰后的RNA能够被m^6A识别蛋白特异性识别并结合,进而介导RNA的剪接、成熟、出核、降解和翻译等。目前国内外对于m^6A修饰及其相关蛋白如何参与非小细胞肺癌发生发展的研究,主要集中于细胞恶性增殖、迁移、侵袭、转移和耐药等方面。m^6A修饰相关蛋白在肺癌组织标本和血液循环肿瘤细胞(circulating tumor cell, CTC)中表达异常,有望成为肺癌诊断和预后判断的潜在分子标志物。本文围绕m^6A修饰相关蛋白的组成、作用方式、在非小细胞肺癌恶性进展中的生物学功能,以及针对m^6A修饰的靶向治疗等方面的研究进展进行综述,旨在为非小细胞肺癌的早期临床诊断和靶向药物的开发提供新思路。

m^(6)A及m^(5)C甲基化修饰通过促进细胞增殖与转移影响癌症的发生和发展

在RNA中已经发现了170多种化学修饰,RNA甲基化修饰是一个重要的转录后修饰过程,N6-甲基腺苷(m^(6)A)和5-甲基胞嘧啶(m^(5)C)普遍存在于真核生物和原核生物中,使得RNA甲基化在调控基因表达进而影响细胞生物活性的研究越来越受到重视。与细胞增殖和转移有关的信号通路调控肿瘤免疫、代谢等细胞活动,并在调节器官大小、组织再生和干细胞自我更新中起着关键作用,影响癌症的发生和发展。在本综述中,我们讨论m^(6)A及m^(5)C甲基化修饰通过一些热门通路调控癌症的发生和发展,这为我们从RNA甲基化的角度理解疾病和寻找新的治疗方法提供了新的理论基础。

RNA m^(6)A修饰在肺部疾病中的研究进展

N^(6)-甲基腺苷(N^(6)-methyladenosine,m^(6)A)修饰是指RNA中腺苷的第6位氮原子处发生的甲基化修饰。在已发现的RNA修饰中,m^(6)A修饰被认为是真核生物mRNA中最常见的修饰类型。此外,这种甲基化修饰也可发生在rRNA、tRNA、miRNA、circRNA和lncRNA[1]。

Prognostic Evaluation for Oral Squamous Cell Carcinoma:A Novel Method Based on m6A Methylation Regulators

Objective:This study aimed to examine a novel method for prognostic evaluation of patients with oral squamous cell carcinoma(OSCC)based on the expression of heterogeneous nuclear ribonucleoprotein C(HNRNPC),YTH domain-binding protein 2(YTHDF2),and methyltransferase 14(METTL14).Methods:We obtained the RNA sequence and clinical information of OSCC patients from The Cancer Genome Atlas database.An optical method was established by the least absolute shrinkage and selection operator Cox regression algorithm,which was used to calculate the risk score of every sample.In addition,all samples(n=239)were classified into high-risk(n=119)and low-risk(n=120)groups,and the overall survival(OS)time and clinical characteristics were compared between groups.Moreover,bioinformatics analysis was carried out.Gene set enrichment analysis was performed to investigate the signaling pathways of HNRNPC,YTHDF2,and METTL14.Results:The two groups showed significantly different OS time,tumor grades,tumor stages,and pathologic T stages(P<0.05).The receiver operating characteristic analysis identified that our method was effective and it was more accurate than use of age,gender,tumor grade,tumor stage,pathologic T stage,and pathologic N stage in OSCC prognostic prediction.Gene set enrichment analysis revealed that HNRNPC,YTHDF2,and METTL14 were mainly associated with ubiquitin-mediated proteolysis,cell cycle,RNA degradation,and spliceosome signaling pathways.Conclusion:The method based on the expression of HNRNPC,YTHDF2,and METTL14 can predict the prognosis of patients with OSCC independently,and its prognostic value is better than that of clinicopathological characteristic indicators.

m^(6)A甲基化在肺癌发生发展中调控机制的研究进展

N6-甲基腺嘌呤修饰(N^(6)-methyladenosine,m^(6)A)是真核细胞中最常见的RNA修饰形式之一,属于表观遗传学修饰的范畴,涉及多种肿瘤的发生和发展。肺癌是全球癌症死亡率最高的恶性肿瘤之一,其发病机制复杂,且早期诊断困难,治疗手段有限。m^(6)A修饰在肺癌中发挥重要作用,相关分子的表达异常导致m^(6)A修饰的失调,从而影响到肺癌的发展。这一现象提示m^(6)A修饰相关分子可能成为肺癌治疗的潜在靶点或诊断标志物。因此,本文综述了m^(6A)修饰在肺癌发生发展过程中的作用,探讨了其与肺癌细胞生物行为及微环境的关系,并讨论了m^(6)A修饰与肺癌相关信号通路之间的相互作用,为深入理解m^(6)A甲基化在肺癌发生和发展中的作用提供了宝贵的参考,对于开发新的诊断和治疗策略具有重要意义。

m^(6)A RNA甲基化修饰在常见心血管疾病和心肌肥大中的研究进展

心血管疾病是影响全球伤残调整生命年和导致死亡的主要原因。最近研究报道,mRNA最普遍的内部修饰N6-腺苷酸甲基化(m^(6)A)在心血管疾病中发挥重要作用。本文概述了m^(6)A RNA甲基化修饰的关键酶及动态调节过程,重点阐述了m^(6)A RNA甲基化在心肌肥大和心力衰竭、高血压、冠状动脉粥样硬化性心脏病、心律失常等常见心血管疾病中的研究进展,并对m^(6)A RNA甲基化新技术进行了讨论。

The landscape of epigenetic regulation and therapeutic application of N^(6)-methyladenosine modifications in non-coding RNAs

RNA N^(6)-methyladenosine(m^(6)A)methylation is the most abundant and conserved RNA modification in eukaryotes.It participates in the regulation of RNA metabolism and various pathophysiological processes.Non-coding RNAs(ncRNAs)are defined as small or long transcripts which do not encode proteins and display numerous biological regulatory functions.Similar to mRNAs,m^(6)A deposition is observed in ncRNAs.Studying RNA m^(6)A modifications on ncRNAs is of great importance specifically to deepen our understanding of their biological roles and clinical implications.In this review,we summarized the recent research findings regarding the mutual regulation between RNA m^(6)A modification and ncRNAs(with a specific focus on microRNAs,long non-coding RNAs,and circular RNAs)and their functions.We also discussed the challenges of m^(6)A-containing ncRNAs and RNA m^(6)A as therapeutic targets in human diseases and their future perspective in translational roles.

Regulation of m^(6)Am RNA modification and its implications in human diseases

N6,2′-O-dimethyladenosine(m^(6)Am)is a prevalent modification frequently found at the 5′cap-adjacent adenosine of messenger RNAs(mRNAs)and small nuclear RNAs(snRNAs)and the internal adenosine of snRNAs.This dynamic and reversible modification is under the regulation of methyltransferases phosphorylated CTD interacting factor 1 and methyltransferase-like protein 4,along with the demethylase fat mass and obesity-associated protein.m^(6)Am RNA modification plays a crucial role in the regulation of pre-mRNA splicing,mRNA stability,and translation,thereby influencing gene expression.In recent years,there has been growing interest in exploring the functions of m^(6)Am and its relevance to human diseases.In this review,we provide a comprehensive overview of the current knowledge concerning m^(6)Am,with a focus on m^(6)Am-modifying enzymes,sequencing approaches for its detection,and its impacts on pre-mRNA splicing,mRNA stability,and translation regulation.Furthermore,we highlight the roles of m^(6)Am in the context of obesity,viral infections,and cancers,unravelling its underlying regulatory mechanisms.

The role of m^(6)A RNA methylation in autoimmune diseases: Novel therapeutic opportunities

N6-methyladenosine m^(6)A modifications,as one of the most common forms of in-ternal RNA chemical modifications in eukaryotic cells,have gained increasing attention in recent years.The m^(6)A RNA modifications exert various crucial roles in various biological pro-cesses,such as embryonic development,neurogenesis,circadian rhythms,and tumorigenesis.Recent advances have highlighted that m^(6)A RNA modification plays an important role in im-mune response,especially in the initiation and progression of autoimmune diseases.In this re-view,we summarized the regulatory mechanisms of m^(6)A methylation and its biological functions in the immune system and mainly focused on recent progress in research on the po-tential role of m^(6)A RNA methylation in the pathogenesis of autoimmune diseases,thus providing possible biomarkers and potential targets for the prevention and treatment of auto-immunediseases.

Dynamic RNA methylation modifications and their regulatory role in mammalian development and diseases

Among over 170 different types of chemical modifications on RNA nucleobases identified so far,RNA methylation is the major type of epitranscriptomic modifications existing on almost all types of RNAs,and has been demonstrated to participate in the entire process of RNA metabolism,including transcription,pre-mRNA alternative splicing and maturation,mRNA nucleus export,mRNA degradation and stabilization,mRNA translation.Attributing to the development of high-throughput detection technologies and the identification of both dynamic regulators and recognition proteins,mechanisms of RNA methylation modification in regulating the normal development of the organism as well as various disease occurrence and developmental abnormalities upon RNA methylation dysregulation have become increasingly clear.Here,we particularly focus on three types of RNA methylations:N^(6)-methylcytosine(m^(6)A),5-methylcytosine(m^(5)C),and N^(7)-methyladenosine(m^(7)G).We summarize the elements related to their dynamic installment and removal,specific binding proteins,and the development of high-throughput detection technologies.Then,for a comprehensive understanding of their biological significance,we also overview the latest knowledge on the underlying mechanisms and key roles of these three mRNA methylation modifications in gametogenesis,embryonic development,immune system development,as well as disease and tumor progression.

m^(6)A修饰在肝细胞癌发生发展及治疗中作用的研究进展

肝细胞癌(hepatocellular carcinoma,HCC)是世界上第六大最常见的恶性肿瘤,也是肿瘤相关死亡的第四大原因[1]。据报道,2018年全球新增病例约841000例,死亡病例约781000例[2]。由于其早期症状隐匿,多数患者确诊时已处于疾病晚期,因此HCC的发病率与死亡率之比接近1[3]。目前,HCC潜在的分子发病机制在很大程度上尚不清楚[4]。探索HCC发生发展的分子机制对HCC早期诊断、精准治疗至关重要。

RNA N^(6)-腺苷酸甲基化修饰及其生物学功能

N^(6)-腺苷酸甲基化(N^(6)-methyladenosine,m^(6)A)是真核生物mRNA的一种转录后修饰,是一个动态可逆过程,由甲基转移酶、去甲基化酶和结合蛋白催化,介导真核生物的各种生物学过程,参与多种细胞基因表达调控和疾病的病理过程。近年来,随着人们对RNA修饰认识的不断深入和和高通量测序技术的发展,人们对m^(6)A甲基化修饰在细胞分化、动物生长发育、疾病的发生等生物学功能的探索也越来越迫切。作者介绍了m^(6)A甲基化修饰的特征及其相关的3种酶、m^(6)A修饰的检测技术,及其在mRNA调控、干细胞分化、肿瘤发生和转移上的生物学功能,简述了m^(6)A甲基化修饰对畜禽(如猪、鸡)生长发育方面的调控,最后对m^(6)A甲基化修饰在未来的研究方向及发展前景做出展望,以期为后续m^(6)A甲基化修饰在动物生长过程中的深入研究和预防治疗疾病上的应用提供参考。