DNA methyltransferases(DNMTs)are an evolutionarily conserved family of DNA methylases,transferring a methyl group onto the fifth carbon of a cytosine residue.The mammalian DNMT family includes three major members that...DNA methyltransferases(DNMTs)are an evolutionarily conserved family of DNA methylases,transferring a methyl group onto the fifth carbon of a cytosine residue.The mammalian DNMT family includes three major members that have functional methylation activities,termed DNMT1,DNMT3A,and DNMT3B.DNMT3A and DNMT3B are responsible for methylation establishment,whereas DNMT1 maintains methylation during DNA replication.Accumulating evidence demonstrates that regulation of DNAmethylation by DNMTs is critical for normal hematopoiesis.Aberrant DNA methylation due to DNMT dysregulation and mutations is known as an important molecular event of hematological malignancies,such as DNMT3A mutations in acute myeloid leukemia.In this reviewwe first describe the basic methylation mechanisms of DNMTs and their functions in lymphocyte maturation and differentiation,We then discuss the current understanding of DNA methylation heterogeneity in leukemia and lymphoma to highlight the importance of studying DNA methylation targets.We also discuss DNMT mu-tations and pathogenic roles in human leukemia and lymphoma.We summarize the recent understanding of how DNMTs interact with transcription factors or cofactors to repress the expression of tumor suppressor genes.Firnally.we highlight current clinical studies using DNMT inhibitors for the treatment of these hematological malignancies.展开更多
Chemically modified cellular co-factors that provide function,such as immobilization or incorporation of fluorescent dyes,are valuable probes of biological activity.A convenient route to obtain S-adenosyl methionine（...Chemically modified cellular co-factors that provide function,such as immobilization or incorporation of fluorescent dyes,are valuable probes of biological activity.A convenient route to obtain S-adenosyl methionine（AdoMet） analogues modified at N-6 adenosine to feature a linker terminating in azide functionality is described herein.Subsequent decoration of such AdoMet analogues with guanidinium terminated linkers leads to novel potential bisubstrate inhibitors for protein arginine methyltrans-ferases, PRMTs.展开更多
DNA methyltransferases 1 (DNMT1) has been looked as crucial targets against various types of cancers. MD simulations have advanced to a point where the atomic level information of biological macromolecule (protein or ...DNA methyltransferases 1 (DNMT1) has been looked as crucial targets against various types of cancers. MD simulations have advanced to a point where the atomic level information of biological macromolecule (protein or DNA-protein or protein-protein) can easily be advantageous to predict the functionality. In this study we utilize xanthomicrol and galloyl compounds to investigate potential compounds for the inhibition of DNMT1, and the results of these two compounds are compared with drug decitabine. Xanthomicrol and galloyl are found to dock successfully within the active site of DNMT1. A comparison of the inhibitory potential of screened xanthomicrol inhibited DNMT1 approximately is identical with those of their corresponding drugs, decitabine. The stability of the DNMT1 with the best docked xanthomicrol, were further analysed in molecular dynamics (MD) simulation and compared with those of the respective drugs namely decitabine which revealed stabilization of these complexes within 300 ns of simulation with better stability of DNMT1.展开更多
Background:Colorectal cancer(CRC)is one of the most frequently diagnosed cancers.In many cases,the poor prognosis of advanced CRC is associated with resistance to treatment with chemotherapeutic drugs such as 5-Fluoro...Background:Colorectal cancer(CRC)is one of the most frequently diagnosed cancers.In many cases,the poor prognosis of advanced CRC is associated with resistance to treatment with chemotherapeutic drugs such as 5-Fluorouracil(5-FU).The epithelial-to-mesenchymal transition(EMT)and dysregulation in protein methylation are two mechanisms associated with chemoresistance in many cancers.This study looked into the effect of 5-FU dose escalation on EMT and protein methylation in CRC.Materials and Methods:HCT-116,Caco-2,and DLD-1 CRC cell lines were exposed to dose escalation treatment of 5-FU.The motility and invasive potentials of the cells before and after treatment with 5-FU were investigated through wound healing and invasion assays.This was followed by aWestern blot which analyzed the protein expressions of the epithelial marker E-cadherin,mesenchymal marker vimentin,and the EMT transcription factor(EMTTF),the snail family transcriptional repressor 1(Snail)in the parental and desensitized cells.Western blotting was also conducted to study the protein expressions of the protein methyltransferases(PMTs),Euchromatic histone lysine methyltransferase 2(EHMT2/G9A),protein arginine methyltransferase(PRMT5),and SET domain containing 7/9(SETD7/9)along with the global lysine and arginine methylation profiles.Results:The dose escalation method generated 5-FU desensitized CRC cells with distinct morphological features and increased tolerance to high doses of 5-FU.The 5-FU desensitized cells experienced a decrease in migration and invasion when compared to the parental cells.This was reflected in the observed reduction in E-cadherin,vimentin,and Snail in the desensitized cell lines.Additionally,the protein expressions of EHMT2/G9A,PRMT5,and SETD7/9 also decreased in the desensitized cells and global protein lysine and arginine methylation became dysregulated with 5-FU treatment.Conclusion:This study showed that continuous,dose-escalation treatment of 5-FU in CRC cells generated 5-FU desensitized cancer cells that seemed to be less aggressive than parental cells.展开更多
Mesenchymal stem cells （MSCs） are characterized by their self-renewing capacity and differentiation potential into multiple tissues. Thus, management of the differentiation capacities of MSCs is important for MSC-ba...Mesenchymal stem cells （MSCs） are characterized by their self-renewing capacity and differentiation potential into multiple tissues. Thus, management of the differentiation capacities of MSCs is important for MSC-based regenerative medicine, such as craniofacial bone regeneration, and in new treatments for metabolic bone diseases, such as osteoporosis. In recent years, histone modification has been a growing topic in the field of MSC lineage specification, in which the Su（var）3-9, enhancer-of-zeste, trithorax （SET） domain-containing family and the Jumonji C （JmjC） domain-containing family represent the major histone lysine methyltransferases （KMTs） and histone lysine demethylases （KDMs）, respectively. In this review, we summarize the current understanding of the epigenetic mechanisms by which SET domain-containine KMTs and JmiC domain-containinlz KDMs balance the osteogenic and adipogenic differentiation of MSCs.展开更多
The limited regenerative capacity of neuronal cells requires tight orchestration of cell death and survival regulation in the context of longevity, age-associated diseases as well as during the development of the nerv...The limited regenerative capacity of neuronal cells requires tight orchestration of cell death and survival regulation in the context of longevity, age-associated diseases as well as during the development of the nervous system. Subordinate to genetic networks epigenetic mechanisms like DNA methylation and histone modifications are involved in the regulation of neuronal development, function and aging. DNA methylation by DNA methyltransferases （DNMTs）, mostly correlated with gene silencing, is a dynamic and reversible process. In addition to their canonical actions performing cytosine methylation, DNMTs influence gene expression by interactions with histone modifying enzymes or complexes increasing the complexity of epigenetic transcriptional networks. DNMTs are expressed in neuronal progenitors, post-mi- totic as well as adult neurons. In this review, we discuss the role and mode of actions of DNMTs including downstream networks in the regulation of neuronal survival in the developing and aging nervous system and its relevance for associated disorders.展开更多
Bisperoxo(1,10-phenanthroline) oxovanadate(BpV) can reportedly block the cell cycle. The present study examined whether BpV alters gene expression by affecting DNA methyltransferases(DNMTs), which would impact the cel...Bisperoxo(1,10-phenanthroline) oxovanadate(BpV) can reportedly block the cell cycle. The present study examined whether BpV alters gene expression by affecting DNA methyltransferases(DNMTs), which would impact the cell cycle. Immortalized mouse hippocampal neuronal precursor cells(HT_(22)) were treated with 0.3 or 3 μM BpV. Proliferation, morphology, and viability of HT_(22) cells were detected with an IncuCyte real-time video imaging system or inverted microscope and 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethonyphenol)-2-(4-sulfophenyl)-2H-tetrazolium, respectively. mRNA and protein expression of DNMTs and p21 in HT_(22) cells was detected by real-time polymerase chain reaction and immunoblotting, respectively. In addition, DNMT activity was measured with an enzyme-linked immunosorbent assay. Effects of BpV on the cell cycle were analyzed using flow cytometry. Results demonstrated that treatment with 0.3 μM BpV did not affect cell proliferation, morphology, or viability; however, treatment with 3 μM BpV decreased cell viability, increased expression of both DNMT3B mRNA and protein, and inhibited the proliferation of HT_(22) cells; and 3 μM BpV also blocked the cell cycle and increased expression of the regulatory factor p21 by increasing DNMT expression in mouse hippocampal neurons.展开更多
DNA methylation is an important epigenetic regulation mechanism,which is catalyzed by DNA methyltransferases.In this study,eight DNA methyltransferase genes were identified in grape genome to analyze the selective pre...DNA methylation is an important epigenetic regulation mechanism,which is catalyzed by DNA methyltransferases.In this study,eight DNA methyltransferase genes were identified in grape genome to analyze the selective pressure,gene expression and codon usage bias.The results showed grape DNA methyltransferase MET subfamily underwent relatively strong purifying selection during evolution,while chromomethylase CMT subfamily underwent positive selection during evolution.Under different abiotic(heat,drought or cold)stresses,the expression level of many grape DNA methyltransferase genes changed significantly.The expression level of these genes might be related with cis-regulatory elements of their promoters.The results of codon usage bias analysis showed that synonymous codon bias existed in grape DNA methyltransferase gene family,which might be affected by mutation pressure.These results laid a solid foundation for in-depth study of DNA methyltransferases in grape.展开更多
The reversible and precise temporal and spatial regulation of histone lysine methyltransferases(KMTs)is essential for epigenome homeostasis.The dysregulation of KMTs is associated with tumor initiation,metastasis,chem...The reversible and precise temporal and spatial regulation of histone lysine methyltransferases(KMTs)is essential for epigenome homeostasis.The dysregulation of KMTs is associated with tumor initiation,metastasis,chemoresistance,invasiveness,and the immune microenvironment.Therapeutically,their promising effects are being evaluated in diversified preclinical and clinical trials,demonstrating encouraging outcomes in multiple malignancies.In this review,we have updated recent understandings of KMTs'functions and the development of their targeted inhibitors.First,we provide an updated overview of the regulatory roles of several KMT activities in oncogenesis,tumor suppression,and immune regulation.In addition,we summarize the current targeting strategies in different cancer types and multiple ongoing clinical trials of combination therapies with KMT inhibitors.In summary,we endeavor to depict the regulation of KMT-mediated epigenetic landscape and provide potential epigenetic targets in the treatment of cancers.展开更多
DNA methylation is a crucial epigenetic regulatory mechanism that can modify chromatin structure,DNA conformation,DNA stability,and the interactions between DNA and proteins,thereby controlling gene expression.It has ...DNA methylation is a crucial epigenetic regulatory mechanism that can modify chromatin structure,DNA conformation,DNA stability,and the interactions between DNA and proteins,thereby controlling gene expression.It has been shown to play a significant role in pathological processes such as fibrosis and tumorigenesis.DNA methyltransferases(DNMTs)are key players in this process.This study aims to investigate the role of DNMTs in the development of urinary system diseases,such as renal fibrosis and prostate cancer,revealing how they regulate gene expression by modulating DNA methylation levels,thereby significantly promoting the progression of these diseases.Additionally,this review explores their potential clinical applications as therapeutic targets,which may offer new research directions for understanding the pathogenesis and treatment of urinary system diseases in the future.展开更多
Transfer RNA methyltransferases(tRNA MTases)catalyze site-specific methylation on tRNAs,a critical process that ensures the stability and functionality of tRNA molecules,thereby maintaining cellular homeostasis of tRN...Transfer RNA methyltransferases(tRNA MTases)catalyze site-specific methylation on tRNAs,a critical process that ensures the stability and functionality of tRNA molecules,thereby maintaining cellular homeostasis of tRNA methylation.Recent studies have illuminated the structural diversity,specific substrate recognition,and conserved catalytic mechanisms of tRNA MTases,revealing how their dysregulation contributes to various diseases,including cancers and neurodevelopmental disorders.This review integrates these advances,exploring the challenges of achieving precise substrate recognition and modification in the context of complex and specific tRNA modification landscape,while emphasizing the crucial role of tRNA MTases in disease pathogenesis.The identification of small-molecule inhibitors targeting specific tRNA MTases marks a promising step toward the development of novel therapies.With continued research into the broader biological functions and regulatory mechanisms of tRNA MTases,these insights hold great potential to drive clinical advancements and therapeutic innovations.展开更多
The beneficial effects of folic acid(FA)on intestinal barrier function are well recognized,however the underlying molecular mechanisms remain largely unexplored.This study aimed to investigate the effects of dietary F...The beneficial effects of folic acid(FA)on intestinal barrier function are well recognized,however the underlying molecular mechanisms remain largely unexplored.This study aimed to investigate the effects of dietary FA on intestinal epithelial function in grass carp,and to reveal the potential molecular mechanism.The total of 450 healthy grass carp(686.83±1.31 g)were randomly divided into 6 groups(18 barrels,25 fish per barrel),and fed diets containing levels of FA(0.57,1.11,1.53,2.08,2.64,and 3.15 mg/kg diet)for 8 weeks.The results showed that,compared with the control group,a dietary FA level of 1.11 mg/kg significantly significantly increased FBW,PWG,WG,SGR and FI,as well as FA and methionine cycling in grass carp(P<0.05).Dietary FA also promoted the intestinal barrier function and proliferation of intestinal epithelial cells(P<0.05).Further,dietary FA increased the protein levels of the DNA methyltransferase(DNMT)family and the protein phosphatase 2A(PP2A)-p38 signaling pathway was significantly activated in fish fed the 1.11 mg/kg FA diet(P<0.05).In conclusion,dietary FA improved intestinal epithelial function in grass carp by modulating the expression of DNMTs and activating the PP2A-p38 signaling pathway.Based on percent weight gain,the optimal requirement of FA for sub-adult grass carp(686.8-1264.7 g)was estimated to be 1.03 mg/kg.展开更多
Histone lysine methyltransferases(HKMTs)deposit methyl groups onto lysine residues on histones and play important roles in regulating chromatin structure and gene expression.The structures and functions of HKMTs have ...Histone lysine methyltransferases(HKMTs)deposit methyl groups onto lysine residues on histones and play important roles in regulating chromatin structure and gene expression.The structures and functions of HKMTs have been extensively investigated in recent decades,significantly advancing our understanding of the dynamic regulation of histone methylation.Here,we review the recent progress in structural studies of representative HKMTs in complex with nucleosomes(H3K4,H3K27,H3K36,H3K79,and H4K20 methyltransferases),with emphasis on the molecular mechanisms of nucleosome recognition and trans-histone crosstalk by these HKMTs.These structural studies inform HKMTs'roles in tumorigenesis and provide the foundations for developing new therapeutic approachestargetingHKMTs incancers.展开更多
Background Normal testicular development is essential for maintaining male fertility and reproductive performance in livestock.Leydig cells(LCs)play a central role in testicular physiology;however,the epigenetic mecha...Background Normal testicular development is essential for maintaining male fertility and reproductive performance in livestock.Leydig cells(LCs)play a central role in testicular physiology;however,the epigenetic mechanisms regulating their development remain largely unclear.Methyltransferase-like 3(METTL3),a key m^(6)A methylation enzyme,and micro RNAs are increasingly recognised as critical regulators of this process.Results METTL3 expression in goat LCs markedly decreased during testicular development.This downregulation reduced m^(6)A modification on pri-miR-145,impairing Di George syndrome critical region 8-mediated processing and resulting in decreased levels of mature mi R-145-3p.This reduction in mi R-145-3p increased the expression of phosphoenolpyruvate carboxykinase 1(PCK1),which activated gluconeogenesis,increased intracellular glucose levels,and increased mitochondrial membrane potential.Consequently,this metabolic shift upregulated cell cyclerelated genes(cyclin B1 and cyclin E2),promoting LC proliferation and testicular growth.Conclusions Our findings demonstrate that the METTL3/mi R-145-3p/PCK1 axis is a key regulatory pathway linking epigenetic modification to the metabolic activity and proliferation of LCs.This mechanism provides novel insights into the molecular control of testicular development in male goats and may offer new targets for improving male reproductive capacity in livestock.展开更多
Rubisco and fructose-1,6-bisphosphate aldolases （FBAs） are involved in CO2 fixation in chloroplasts. Both enzymes are trimethylated at a specific lysine residue by the chloroplastic protein methyltransferase LSMT. G...Rubisco and fructose-1,6-bisphosphate aldolases （FBAs） are involved in CO2 fixation in chloroplasts. Both enzymes are trimethylated at a specific lysine residue by the chloroplastic protein methyltransferase LSMT. Genes coding LSMT are present in all plant genomes but the methylation status of the substrates varies in a species-specific manner. For example, chloroplastic FBAs are naturally trimethylated in both Pisum sati- vum and Arabidopsis thaliana, whereas the Rubisco large subunit is trimethylated only in the former spe- cies. The in vivo methylation status of aldolases and Rubisco matches the catalytic properties of AtLSMT and PsLSMT, which are able to trimethylate FBAs or FBAs and Rubisco, respectively. Here, we created chimera and site-directed mutants of monofunctional AtLSMT and bifunctional PsLSMT to identify the molecular determinants responsible for substrate specificity. Our results indicate that the His-Ala/Pro- Trp triad located in the central part of LSMT enzymes is the key motif to confer the capacity to trimethylate Rubisco. Two of the critical residues are located on a surface loop outside the methyltransferase catalytic site. We observed a strict correlation between the presence of the triad motif and the in vivo methylation status of Rubisco. The distribution of the motif into a phylogenetic tree further suggests that the ancestral function of LSMT was FBA trimethylation. In a recent event during higher plant evolution, this function evolved in ancestors of Fabaceae, Cucurbitaceae, and Rosaceae to include Rubisco as an additional substrate to the archetypal enzyme. Our study provides insight into mechanisms by which SET-domain protein methyltransferases evolve new substrate specificity.展开更多
Recently,two studies published in Nature identified genetic changes in the nuclear receptor-binding SET domain protein(NSD)family of histone methyltransferases as oncogenic drivers in some malignancies,and revealed th...Recently,two studies published in Nature identified genetic changes in the nuclear receptor-binding SET domain protein(NSD)family of histone methyltransferases as oncogenic drivers in some malignancies,and revealed the nucleosome-based recognition and histone-modification mechanisms of NSD2 and NSD3.展开更多
Hypoxemia is a common pathological state characterized by low oxygen saturation in the blood.This condition compromises mucosal barrier integrity particularly in the gut and oral cavity.However,the mechanisms underlyi...Hypoxemia is a common pathological state characterized by low oxygen saturation in the blood.This condition compromises mucosal barrier integrity particularly in the gut and oral cavity.However,the mechanisms underlying this association remain unclear.This study used periodontitis as a model to investigate the role of platelet activation in oral mucosal immunopathology under hypoxic conditions.Hypoxia upregulated methyltransferase-like protein 4(METTL4)expression in platelets,resulting in N6-methyladenine modification of mitochondrial DNA(mtDNA).This modification impaired mitochondrial transcriptional factor A-dependent cytosolic mtDNA degradation,leading to cytosolic mtDNA accumulation.Excess cytosolic mt-DNA aberrantly activated the cGAS-STING pathway in platelets.This resulted in excessive platelet activation and neutrophil extracellular trap formation that ultimately exacerbated periodontitis.Targeting platelet METTL4 and its downstream pathways offers a potential strategy for managing oral mucosa immunopathology.Further research is needed to examine its broader implications for mucosal inflammation under hypoxic conditions.展开更多
Objective To investigate the effects of calprotectin(S100A8/A9)on the biological activity of acute myeloid leukemia(AML)cells harboring a DNA methyltransferase 3A(DNMT3A)mutation and to explore the underlying molecula...Objective To investigate the effects of calprotectin(S100A8/A9)on the biological activity of acute myeloid leukemia(AML)cells harboring a DNA methyltransferase 3A(DNMT3A)mutation and to explore the underlying molecular mechanisms involved.Methods AML monoclonal cell lines harboring the DNMT3A^(R882H) mutation were generated via lentiviral transduction and limiting dilution.RNA sequencing was used for differential gene expression analysis,followed by bioinformatic pathway enrichment and gene correlation analyses.The biological effects of paquinimod,a selective S100A8/A9 inhibitor,on DNMT3A^(R882H) AML cells were assessed via Cell Counting Kit(CCK-8)proliferation assays,Annexin V/PI staining,cell cycle analysis,cell adhesion assays,and transwell migration assays.Results Differential gene expression analysis revealed 442 upregulated and 535 downregulated genes in DNMT3A-mutated(DNMT3A^(mut))cells compared with those in DNMT3A wild-type(DNMT3A^(wt))cells,with the S100A8/A9 complex recurrently enriched in Reactome pathway analysis.Compared with healthy controls,patients with AML presented increased expression of S100A8 and S100A9 and increased expression of DNMT3A^(mut) cells relative to DNMT3A^(wt) cells,which was correlated with poor prognosis in patients with AML.There were no notable differences in proliferation among the DNMT3A^(mut),DNMT3A^(wt),and empty vector cells under normal or starvation conditions.However,paquinimod treatment notably inhibited the proliferation,migration,and adhesion of DNMT3A^(mut) AML cells in a dose-dependent manner,causing G0/G1 cell cycle arrest,whereas no significant effects on apoptosis were observed.Paquinimod also downregulated key adhesion molecules,including intercellular adhesion molecule 1(ICAM-1),vascular cell adhesion molecule 1(VCAM-1),monocyte chemoattractant protein-1(MCP-1),and matrix metalloproteinase-2(MMP-2).Additionally,S100A8 and S100A9 expression was upregulated in a dose-dependent manner in response to cytarabine treatment.Conclusion Elevated S100A8/A9 expression contributes to the abnormal proliferation,migration,adhesion,and chemoresistance of DNMT3A^(mut) AML cells.Targeting S100A8/A9 alone or in combination with other treatments represents a promising therapeutic strategy for DNMT3A^(mut) AML.展开更多
Spinal cord injury typically causes corticospinal tract disruption.Although the disrupted corticospinal tract can self-regenerate to a certain degree,the underlying mechanism of this process is still unclear.N6-methyl...Spinal cord injury typically causes corticospinal tract disruption.Although the disrupted corticospinal tract can self-regenerate to a certain degree,the underlying mechanism of this process is still unclear.N6-methyladenosine(m^(6)A)modifications are the most common form of epigenetic regulation at the RNA level and play an essential role in biological processes.However,whether m^(6)A modifications participate in corticospinal tract regeneration after spinal cord injury remains unknown.We found that expression of methyltransferase 14 protein(METTL14)in the locomotor cortex was high after spinal cord injury and accompanied by elevated m^(6)A levels.Knockdown of Mettl14 in the locomotor cortex was not favorable for corticospinal tract regeneration and neurological recovery after spinal cord injury.Through bioinformatics analysis and methylated RNA immunoprecipitation-quantitative polymerase chain reaction,we found that METTL14 regulated Trib2 expression in an m^(6)A-regulated manner,thereby activating the mitogen-activated protein kinase pathway and promoting corticospinal tract regeneration.Finally,we administered syringin,a stabilizer of METTL14,using molecular docking.Results confirmed that syringin can promote corticospinal tract regeneration and facilitate neurological recovery by stabilizing METTL14.Findings from this study reveal that m^(6)A modification is involved in the regulation of corticospinal tract regeneration after spinal cord injury.展开更多
基金the National lnstitutes of Health/National Cancer Institute(NlH/NCT)grant RO1 CA187299(L.R.)。
文摘DNA methyltransferases(DNMTs)are an evolutionarily conserved family of DNA methylases,transferring a methyl group onto the fifth carbon of a cytosine residue.The mammalian DNMT family includes three major members that have functional methylation activities,termed DNMT1,DNMT3A,and DNMT3B.DNMT3A and DNMT3B are responsible for methylation establishment,whereas DNMT1 maintains methylation during DNA replication.Accumulating evidence demonstrates that regulation of DNAmethylation by DNMTs is critical for normal hematopoiesis.Aberrant DNA methylation due to DNMT dysregulation and mutations is known as an important molecular event of hematological malignancies,such as DNMT3A mutations in acute myeloid leukemia.In this reviewwe first describe the basic methylation mechanisms of DNMTs and their functions in lymphocyte maturation and differentiation,We then discuss the current understanding of DNA methylation heterogeneity in leukemia and lymphoma to highlight the importance of studying DNA methylation targets.We also discuss DNMT mu-tations and pathogenic roles in human leukemia and lymphoma.We summarize the recent understanding of how DNMTs interact with transcription factors or cofactors to repress the expression of tumor suppressor genes.Firnally.we highlight current clinical studies using DNMT inhibitors for the treatment of these hematological malignancies.
基金financially supported by the Medical Research Council Grant(No.G0700840)
文摘Chemically modified cellular co-factors that provide function,such as immobilization or incorporation of fluorescent dyes,are valuable probes of biological activity.A convenient route to obtain S-adenosyl methionine（AdoMet） analogues modified at N-6 adenosine to feature a linker terminating in azide functionality is described herein.Subsequent decoration of such AdoMet analogues with guanidinium terminated linkers leads to novel potential bisubstrate inhibitors for protein arginine methyltrans-ferases, PRMTs.
文摘DNA methyltransferases 1 (DNMT1) has been looked as crucial targets against various types of cancers. MD simulations have advanced to a point where the atomic level information of biological macromolecule (protein or DNA-protein or protein-protein) can easily be advantageous to predict the functionality. In this study we utilize xanthomicrol and galloyl compounds to investigate potential compounds for the inhibition of DNMT1, and the results of these two compounds are compared with drug decitabine. Xanthomicrol and galloyl are found to dock successfully within the active site of DNMT1. A comparison of the inhibitory potential of screened xanthomicrol inhibited DNMT1 approximately is identical with those of their corresponding drugs, decitabine. The stability of the DNMT1 with the best docked xanthomicrol, were further analysed in molecular dynamics (MD) simulation and compared with those of the respective drugs namely decitabine which revealed stabilization of these complexes within 300 ns of simulation with better stability of DNMT1.
基金supported through the Faculty of Medicine and Surgery Award 2021 University of Malta(awarded to K.F).
文摘Background:Colorectal cancer(CRC)is one of the most frequently diagnosed cancers.In many cases,the poor prognosis of advanced CRC is associated with resistance to treatment with chemotherapeutic drugs such as 5-Fluorouracil(5-FU).The epithelial-to-mesenchymal transition(EMT)and dysregulation in protein methylation are two mechanisms associated with chemoresistance in many cancers.This study looked into the effect of 5-FU dose escalation on EMT and protein methylation in CRC.Materials and Methods:HCT-116,Caco-2,and DLD-1 CRC cell lines were exposed to dose escalation treatment of 5-FU.The motility and invasive potentials of the cells before and after treatment with 5-FU were investigated through wound healing and invasion assays.This was followed by aWestern blot which analyzed the protein expressions of the epithelial marker E-cadherin,mesenchymal marker vimentin,and the EMT transcription factor(EMTTF),the snail family transcriptional repressor 1(Snail)in the parental and desensitized cells.Western blotting was also conducted to study the protein expressions of the protein methyltransferases(PMTs),Euchromatic histone lysine methyltransferase 2(EHMT2/G9A),protein arginine methyltransferase(PRMT5),and SET domain containing 7/9(SETD7/9)along with the global lysine and arginine methylation profiles.Results:The dose escalation method generated 5-FU desensitized CRC cells with distinct morphological features and increased tolerance to high doses of 5-FU.The 5-FU desensitized cells experienced a decrease in migration and invasion when compared to the parental cells.This was reflected in the observed reduction in E-cadherin,vimentin,and Snail in the desensitized cell lines.Additionally,the protein expressions of EHMT2/G9A,PRMT5,and SETD7/9 also decreased in the desensitized cells and global protein lysine and arginine methylation became dysregulated with 5-FU treatment.Conclusion:This study showed that continuous,dose-escalation treatment of 5-FU in CRC cells generated 5-FU desensitized cancer cells that seemed to be less aggressive than parental cells.
基金supported by the National Institute of Dental and Craniofacial Research grants, K08DE024603-02, DE019412, and DE01651a grant from 111 Project of MOE, Chinasupported by Open Fund of State Key Laboratory of Oral Diseases, Sichuan University
文摘Mesenchymal stem cells （MSCs） are characterized by their self-renewing capacity and differentiation potential into multiple tissues. Thus, management of the differentiation capacities of MSCs is important for MSC-based regenerative medicine, such as craniofacial bone regeneration, and in new treatments for metabolic bone diseases, such as osteoporosis. In recent years, histone modification has been a growing topic in the field of MSC lineage specification, in which the Su（var）3-9, enhancer-of-zeste, trithorax （SET） domain-containing family and the Jumonji C （JmjC） domain-containing family represent the major histone lysine methyltransferases （KMTs） and histone lysine demethylases （KDMs）, respectively. In this review, we summarize the current understanding of the epigenetic mechanisms by which SET domain-containine KMTs and JmiC domain-containinlz KDMs balance the osteogenic and adipogenic differentiation of MSCs.
文摘The limited regenerative capacity of neuronal cells requires tight orchestration of cell death and survival regulation in the context of longevity, age-associated diseases as well as during the development of the nervous system. Subordinate to genetic networks epigenetic mechanisms like DNA methylation and histone modifications are involved in the regulation of neuronal development, function and aging. DNA methylation by DNA methyltransferases （DNMTs）, mostly correlated with gene silencing, is a dynamic and reversible process. In addition to their canonical actions performing cytosine methylation, DNMTs influence gene expression by interactions with histone modifying enzymes or complexes increasing the complexity of epigenetic transcriptional networks. DNMTs are expressed in neuronal progenitors, post-mi- totic as well as adult neurons. In this review, we discuss the role and mode of actions of DNMTs including downstream networks in the regulation of neuronal survival in the developing and aging nervous system and its relevance for associated disorders.
基金supported by the National Natural Science Foundation of China,No.81160244,81360316,81460283,81660307(all to GS)the Inner Mongolia Science Foundation of China,No.2018LH08078(to GS),2016MS(LH)0307(to SYJ)+4 种基金the Baotou Health Foundation,China,No.WSJJ2016008(to SYJ)the Inner Mongolia Educational Research Foundation of China,No.NJZY207(to GS),NJZY17243(to SCY),NJZY17250(to XLL),NJZY17251(to SYJ)the Baotou Medical College Foundation of China,No.BYJJ-DF201602,BYJJ-YF201615,BSJJ201617,BYJJ-QM201633,BYJJ-QM201656,BYJJ201502(to GS)the Science and Technology Planning Project of Baotou of China,No.CX2017-5(to GS)the National Key R&D Program of China,No.2017YFC1308405(to GS)
文摘Bisperoxo(1,10-phenanthroline) oxovanadate(BpV) can reportedly block the cell cycle. The present study examined whether BpV alters gene expression by affecting DNA methyltransferases(DNMTs), which would impact the cell cycle. Immortalized mouse hippocampal neuronal precursor cells(HT_(22)) were treated with 0.3 or 3 μM BpV. Proliferation, morphology, and viability of HT_(22) cells were detected with an IncuCyte real-time video imaging system or inverted microscope and 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethonyphenol)-2-(4-sulfophenyl)-2H-tetrazolium, respectively. mRNA and protein expression of DNMTs and p21 in HT_(22) cells was detected by real-time polymerase chain reaction and immunoblotting, respectively. In addition, DNMT activity was measured with an enzyme-linked immunosorbent assay. Effects of BpV on the cell cycle were analyzed using flow cytometry. Results demonstrated that treatment with 0.3 μM BpV did not affect cell proliferation, morphology, or viability; however, treatment with 3 μM BpV decreased cell viability, increased expression of both DNMT3B mRNA and protein, and inhibited the proliferation of HT_(22) cells; and 3 μM BpV also blocked the cell cycle and increased expression of the regulatory factor p21 by increasing DNMT expression in mouse hippocampal neurons.
基金Supported by Major Agricultural Application Technology Innovation Project of Shandong Province"Research and Application of Precision Control of Maturation and Product Innovation of Featured Brewing Grape"Major Agricultural Application Technology Innovation Project of Shandong Province"Development of Landmark Wines and Integrated Application of Key Technologies in Shandong Province"Agricultural Scientific and Technological Innovation Project of Shandong Academy of Agricultural Sciences(CXGC2016D01)
文摘DNA methylation is an important epigenetic regulation mechanism,which is catalyzed by DNA methyltransferases.In this study,eight DNA methyltransferase genes were identified in grape genome to analyze the selective pressure,gene expression and codon usage bias.The results showed grape DNA methyltransferase MET subfamily underwent relatively strong purifying selection during evolution,while chromomethylase CMT subfamily underwent positive selection during evolution.Under different abiotic(heat,drought or cold)stresses,the expression level of many grape DNA methyltransferase genes changed significantly.The expression level of these genes might be related with cis-regulatory elements of their promoters.The results of codon usage bias analysis showed that synonymous codon bias existed in grape DNA methyltransferase gene family,which might be affected by mutation pressure.These results laid a solid foundation for in-depth study of DNA methyltransferases in grape.
基金the Science and Technology Commission of Shanghai,China(Grant Nos.:20DZ2270800 and 19JC1410200)Innovative Research Team of High-Level Local Universities in Shanghai,China(Grant No.:SHSMU-ZDCX20210900)the National Natural Science Foundation of China(Grant No.:82073889).
文摘The reversible and precise temporal and spatial regulation of histone lysine methyltransferases(KMTs)is essential for epigenome homeostasis.The dysregulation of KMTs is associated with tumor initiation,metastasis,chemoresistance,invasiveness,and the immune microenvironment.Therapeutically,their promising effects are being evaluated in diversified preclinical and clinical trials,demonstrating encouraging outcomes in multiple malignancies.In this review,we have updated recent understandings of KMTs'functions and the development of their targeted inhibitors.First,we provide an updated overview of the regulatory roles of several KMT activities in oncogenesis,tumor suppression,and immune regulation.In addition,we summarize the current targeting strategies in different cancer types and multiple ongoing clinical trials of combination therapies with KMT inhibitors.In summary,we endeavor to depict the regulation of KMT-mediated epigenetic landscape and provide potential epigenetic targets in the treatment of cancers.
基金The Anqing Medical Self-Financing Program,Grant/Award Number:2024Z4002。
文摘DNA methylation is a crucial epigenetic regulatory mechanism that can modify chromatin structure,DNA conformation,DNA stability,and the interactions between DNA and proteins,thereby controlling gene expression.It has been shown to play a significant role in pathological processes such as fibrosis and tumorigenesis.DNA methyltransferases(DNMTs)are key players in this process.This study aims to investigate the role of DNMTs in the development of urinary system diseases,such as renal fibrosis and prostate cancer,revealing how they regulate gene expression by modulating DNA methylation levels,thereby significantly promoting the progression of these diseases.Additionally,this review explores their potential clinical applications as therapeutic targets,which may offer new research directions for understanding the pathogenesis and treatment of urinary system diseases in the future.
基金supported by the National Natural Science Foundation of China(32401073)。
文摘Transfer RNA methyltransferases(tRNA MTases)catalyze site-specific methylation on tRNAs,a critical process that ensures the stability and functionality of tRNA molecules,thereby maintaining cellular homeostasis of tRNA methylation.Recent studies have illuminated the structural diversity,specific substrate recognition,and conserved catalytic mechanisms of tRNA MTases,revealing how their dysregulation contributes to various diseases,including cancers and neurodevelopmental disorders.This review integrates these advances,exploring the challenges of achieving precise substrate recognition and modification in the context of complex and specific tRNA modification landscape,while emphasizing the crucial role of tRNA MTases in disease pathogenesis.The identification of small-molecule inhibitors targeting specific tRNA MTases marks a promising step toward the development of novel therapies.With continued research into the broader biological functions and regulatory mechanisms of tRNA MTases,these insights hold great potential to drive clinical advancements and therapeutic innovations.
基金The earmarked fund for CARS(CARS-45),National Science Fund for Distinguished Young Scholars of China(32425056)the National Key R&D Program of China(2023YFD2400600)Sichuan Innovation Team of National Modern Agricultural Industry Technology System(SCCXTD-2024-15).
文摘The beneficial effects of folic acid(FA)on intestinal barrier function are well recognized,however the underlying molecular mechanisms remain largely unexplored.This study aimed to investigate the effects of dietary FA on intestinal epithelial function in grass carp,and to reveal the potential molecular mechanism.The total of 450 healthy grass carp(686.83±1.31 g)were randomly divided into 6 groups(18 barrels,25 fish per barrel),and fed diets containing levels of FA(0.57,1.11,1.53,2.08,2.64,and 3.15 mg/kg diet)for 8 weeks.The results showed that,compared with the control group,a dietary FA level of 1.11 mg/kg significantly significantly increased FBW,PWG,WG,SGR and FI,as well as FA and methionine cycling in grass carp(P<0.05).Dietary FA also promoted the intestinal barrier function and proliferation of intestinal epithelial cells(P<0.05).Further,dietary FA increased the protein levels of the DNA methyltransferase(DNMT)family and the protein phosphatase 2A(PP2A)-p38 signaling pathway was significantly activated in fish fed the 1.11 mg/kg FA diet(P<0.05).In conclusion,dietary FA improved intestinal epithelial function in grass carp by modulating the expression of DNMTs and activating the PP2A-p38 signaling pathway.Based on percent weight gain,the optimal requirement of FA for sub-adult grass carp(686.8-1264.7 g)was estimated to be 1.03 mg/kg.
基金supported by grants from the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB37010303 to Y.C.)the National Natural Science Foundation of China(31670748,31970576 to Y.C.,and 32071195 and 31900934 to Y.L.)+1 种基金the Young Elite Scientist Sponsorship Program by Chinese Association for Science and Technology(YESS20170198 to Y.L.)the National Postdoctoral Program for Innovative Talents(Bx201700263 to Y.L.).
文摘Histone lysine methyltransferases(HKMTs)deposit methyl groups onto lysine residues on histones and play important roles in regulating chromatin structure and gene expression.The structures and functions of HKMTs have been extensively investigated in recent decades,significantly advancing our understanding of the dynamic regulation of histone methylation.Here,we review the recent progress in structural studies of representative HKMTs in complex with nucleosomes(H3K4,H3K27,H3K36,H3K79,and H4K20 methyltransferases),with emphasis on the molecular mechanisms of nucleosome recognition and trans-histone crosstalk by these HKMTs.These structural studies inform HKMTs'roles in tumorigenesis and provide the foundations for developing new therapeutic approachestargetingHKMTs incancers.
基金supported by the National Natural Science Foundation of China(32260835)Guizhou High-level Innovative Talents Project(Qiankehe Platform Talents[2022]021-1)+2 种基金Guizhou Province Mutton Sheep Genetic Improvement and Innovative Utilization Science and Technology Innovation Talent Team Project(Qian Kehe Platform Talent-CXTD[2023]025)the Natural Science Special Research Fund of Guizhou University(Gui Da Te Gang He Zi[2025]12)Project on the Development of a Technical Support System for the Meat Sheep Industry in Guizhou Province(GZRYCYJSTX-02)。
文摘Background Normal testicular development is essential for maintaining male fertility and reproductive performance in livestock.Leydig cells(LCs)play a central role in testicular physiology;however,the epigenetic mechanisms regulating their development remain largely unclear.Methyltransferase-like 3(METTL3),a key m^(6)A methylation enzyme,and micro RNAs are increasingly recognised as critical regulators of this process.Results METTL3 expression in goat LCs markedly decreased during testicular development.This downregulation reduced m^(6)A modification on pri-miR-145,impairing Di George syndrome critical region 8-mediated processing and resulting in decreased levels of mature mi R-145-3p.This reduction in mi R-145-3p increased the expression of phosphoenolpyruvate carboxykinase 1(PCK1),which activated gluconeogenesis,increased intracellular glucose levels,and increased mitochondrial membrane potential.Consequently,this metabolic shift upregulated cell cyclerelated genes(cyclin B1 and cyclin E2),promoting LC proliferation and testicular growth.Conclusions Our findings demonstrate that the METTL3/mi R-145-3p/PCK1 axis is a key regulatory pathway linking epigenetic modification to the metabolic activity and proliferation of LCs.This mechanism provides novel insights into the molecular control of testicular development in male goats and may offer new targets for improving male reproductive capacity in livestock.
文摘Rubisco and fructose-1,6-bisphosphate aldolases （FBAs） are involved in CO2 fixation in chloroplasts. Both enzymes are trimethylated at a specific lysine residue by the chloroplastic protein methyltransferase LSMT. Genes coding LSMT are present in all plant genomes but the methylation status of the substrates varies in a species-specific manner. For example, chloroplastic FBAs are naturally trimethylated in both Pisum sati- vum and Arabidopsis thaliana, whereas the Rubisco large subunit is trimethylated only in the former spe- cies. The in vivo methylation status of aldolases and Rubisco matches the catalytic properties of AtLSMT and PsLSMT, which are able to trimethylate FBAs or FBAs and Rubisco, respectively. Here, we created chimera and site-directed mutants of monofunctional AtLSMT and bifunctional PsLSMT to identify the molecular determinants responsible for substrate specificity. Our results indicate that the His-Ala/Pro- Trp triad located in the central part of LSMT enzymes is the key motif to confer the capacity to trimethylate Rubisco. Two of the critical residues are located on a surface loop outside the methyltransferase catalytic site. We observed a strict correlation between the presence of the triad motif and the in vivo methylation status of Rubisco. The distribution of the motif into a phylogenetic tree further suggests that the ancestral function of LSMT was FBA trimethylation. In a recent event during higher plant evolution, this function evolved in ancestors of Fabaceae, Cucurbitaceae, and Rosaceae to include Rubisco as an additional substrate to the archetypal enzyme. Our study provides insight into mechanisms by which SET-domain protein methyltransferases evolve new substrate specificity.
基金This work was supported by the National Natural Science Foundation of China(81702286)the Research Fund of Science&Technology Department of Sichuan Province(2021YJ0134,2018JY0652)the Open Project of Radiation Oncology Key Laboratory of Sichuan Province(2020FSZLX04).
文摘Recently,two studies published in Nature identified genetic changes in the nuclear receptor-binding SET domain protein(NSD)family of histone methyltransferases as oncogenic drivers in some malignancies,and revealed the nucleosome-based recognition and histone-modification mechanisms of NSD2 and NSD3.
基金supported by the National Natural Science Foundation of China(82325012)the Youth Fund of the National Natural Science Foundation of China(82301043)+1 种基金the Natural Science Basic Research Program of Shaanxi (Program No.2024JC-YBQN-0980)the Shaanxi Key Scientific and Technological Innovation Team(2020TD-033).
文摘Hypoxemia is a common pathological state characterized by low oxygen saturation in the blood.This condition compromises mucosal barrier integrity particularly in the gut and oral cavity.However,the mechanisms underlying this association remain unclear.This study used periodontitis as a model to investigate the role of platelet activation in oral mucosal immunopathology under hypoxic conditions.Hypoxia upregulated methyltransferase-like protein 4(METTL4)expression in platelets,resulting in N6-methyladenine modification of mitochondrial DNA(mtDNA).This modification impaired mitochondrial transcriptional factor A-dependent cytosolic mtDNA degradation,leading to cytosolic mtDNA accumulation.Excess cytosolic mt-DNA aberrantly activated the cGAS-STING pathway in platelets.This resulted in excessive platelet activation and neutrophil extracellular trap formation that ultimately exacerbated periodontitis.Targeting platelet METTL4 and its downstream pathways offers a potential strategy for managing oral mucosa immunopathology.Further research is needed to examine its broader implications for mucosal inflammation under hypoxic conditions.
基金funded by the National Natural Science Foundation of China(Grant No.82270177)the China Medicine Education Association 2024 Medical Science and Technology Research Project(Grant No.2024KTZ035).
文摘Objective To investigate the effects of calprotectin(S100A8/A9)on the biological activity of acute myeloid leukemia(AML)cells harboring a DNA methyltransferase 3A(DNMT3A)mutation and to explore the underlying molecular mechanisms involved.Methods AML monoclonal cell lines harboring the DNMT3A^(R882H) mutation were generated via lentiviral transduction and limiting dilution.RNA sequencing was used for differential gene expression analysis,followed by bioinformatic pathway enrichment and gene correlation analyses.The biological effects of paquinimod,a selective S100A8/A9 inhibitor,on DNMT3A^(R882H) AML cells were assessed via Cell Counting Kit(CCK-8)proliferation assays,Annexin V/PI staining,cell cycle analysis,cell adhesion assays,and transwell migration assays.Results Differential gene expression analysis revealed 442 upregulated and 535 downregulated genes in DNMT3A-mutated(DNMT3A^(mut))cells compared with those in DNMT3A wild-type(DNMT3A^(wt))cells,with the S100A8/A9 complex recurrently enriched in Reactome pathway analysis.Compared with healthy controls,patients with AML presented increased expression of S100A8 and S100A9 and increased expression of DNMT3A^(mut) cells relative to DNMT3A^(wt) cells,which was correlated with poor prognosis in patients with AML.There were no notable differences in proliferation among the DNMT3A^(mut),DNMT3A^(wt),and empty vector cells under normal or starvation conditions.However,paquinimod treatment notably inhibited the proliferation,migration,and adhesion of DNMT3A^(mut) AML cells in a dose-dependent manner,causing G0/G1 cell cycle arrest,whereas no significant effects on apoptosis were observed.Paquinimod also downregulated key adhesion molecules,including intercellular adhesion molecule 1(ICAM-1),vascular cell adhesion molecule 1(VCAM-1),monocyte chemoattractant protein-1(MCP-1),and matrix metalloproteinase-2(MMP-2).Additionally,S100A8 and S100A9 expression was upregulated in a dose-dependent manner in response to cytarabine treatment.Conclusion Elevated S100A8/A9 expression contributes to the abnormal proliferation,migration,adhesion,and chemoresistance of DNMT3A^(mut) AML cells.Targeting S100A8/A9 alone or in combination with other treatments represents a promising therapeutic strategy for DNMT3A^(mut) AML.
基金supported by the National Natural Science Foundation of China,Nos.82030071(to JH),82272495(to YC)Science and Technology Major Project of Changsha,No.kh2103008(to JH)Graduate Students’Independent Innovative Projects of Hunan Province,No.CX20230311(to YJ)。
文摘Spinal cord injury typically causes corticospinal tract disruption.Although the disrupted corticospinal tract can self-regenerate to a certain degree,the underlying mechanism of this process is still unclear.N6-methyladenosine(m^(6)A)modifications are the most common form of epigenetic regulation at the RNA level and play an essential role in biological processes.However,whether m^(6)A modifications participate in corticospinal tract regeneration after spinal cord injury remains unknown.We found that expression of methyltransferase 14 protein(METTL14)in the locomotor cortex was high after spinal cord injury and accompanied by elevated m^(6)A levels.Knockdown of Mettl14 in the locomotor cortex was not favorable for corticospinal tract regeneration and neurological recovery after spinal cord injury.Through bioinformatics analysis and methylated RNA immunoprecipitation-quantitative polymerase chain reaction,we found that METTL14 regulated Trib2 expression in an m^(6)A-regulated manner,thereby activating the mitogen-activated protein kinase pathway and promoting corticospinal tract regeneration.Finally,we administered syringin,a stabilizer of METTL14,using molecular docking.Results confirmed that syringin can promote corticospinal tract regeneration and facilitate neurological recovery by stabilizing METTL14.Findings from this study reveal that m^(6)A modification is involved in the regulation of corticospinal tract regeneration after spinal cord injury.
