N6-methyladenosine(m6A)is a reversible epigenetic modification, which is one of the most abundant modifiers in eukaryotic cells and has been commonly reported in messenger RNAs and non-coding RNAs. The processing modi...N6-methyladenosine(m6A)is a reversible epigenetic modification, which is one of the most abundant modifiers in eukaryotic cells and has been commonly reported in messenger RNAs and non-coding RNAs. The processing modification of m6A regulates RNA transcription, processing, splicing, degradation, and translation, and plays an important role in the biological process of tumors. Circular RNA, which lacks the 5' cap structure, has been mistakenly regarded as a "junk sequence" generated by accidental shearing during the transcription process. However, it has been found that circRNAs can be involved in tumor invasion and metastasis through microRNAs, binding proteins, translated peptides, and m6A modifications. In this paper, we reviewed the role of m6A modifications in circRNA regulation and their functions in hepatocellular carcinoma and discussed their potential clinical applications and future development in this field.展开更多
N6-methyladenosine(m6A)modification is a reversible process promoted by“writers”,inhibited by“erasers”,and processed by“readers”.During the last decade,increasing emphasis has been placed on the underlying roles...N6-methyladenosine(m6A)modification is a reversible process promoted by“writers”,inhibited by“erasers”,and processed by“readers”.During the last decade,increasing emphasis has been placed on the underlying roles of m6A modification owing to their great importance in biological significance.The abnormal regulation of m6A modification will lead to aberrant cellular behavior and various diseases.Recently,studies have demonstrated that m6A modification is closely associated with the genesis and progression of ocular surface diseases(OSDs).This review focus on the role of m6A modification and research progress in OSDs including fungal keratitis,herpes simplex keratitis,immunerelated keratoconjunctival diseases,pterygium,ocular chemical burns,and Graves’ophthalmopathy,which may provide new insights into and prospective applications for OSDs.展开更多
AIM:To characterize the N6-methyladenosine(m6A)modification patterns in long non-coding RNAs(lncRNAs)in sporadic congenital cataract(CC)and age-related cataract(ARC).METHODS:Anterior capsule of the lens were collected...AIM:To characterize the N6-methyladenosine(m6A)modification patterns in long non-coding RNAs(lncRNAs)in sporadic congenital cataract(CC)and age-related cataract(ARC).METHODS:Anterior capsule of the lens were collected from patients with CC and ARC.Methylated RNA immunoprecipitation with next-generation sequencing and RNA sequencing were performed to identify m6A-tagged lncRNAs and lncRNAs expression.Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses and Gene Ontology annotation were used to predict potential functions of the m6A-lncRNAs.RESULTS:Large amount of m6A peaks within lncRNA were identified for both CC and ARC,while the level was much higher in ARC(49870 peaks)than that in CC(18688 peaks),yet those difference between ARC in younger age group(ARC-1)and ARC in elder age group(ARC-2)was quite slight.A total of 1305 hypermethylated and 1178 hypomethylated lncRNAs,as well as 182 differential expressed lncRNAs were exhibited in ARC compared with CC.On the other hand,5893 hypermethylated and 5213 hypomethylated lncRNAs,as well as 155 significantly altered lncRNA were identified in ARC-2 compared with ARC-1.Altered lncRNAs in ARC were mainly associated with the organization and biogenesis of intracellular organelles,as well as nucleotide excision repair.CONCLUSION:Our results for the first time present an overview of the m6A methylomes of lncRNA in CC and ARC,providing a solid basis and uncovering a new insight to reveal the potential pathogenic mechanism of CC and ARC.展开更多
N6-methyladenosine(m6A)is an important RNA methylation modification involved in regulating diverse biological processes across multiple species.Hence,the identification of m6A modification sites provides valuable insi...N6-methyladenosine(m6A)is an important RNA methylation modification involved in regulating diverse biological processes across multiple species.Hence,the identification of m6A modification sites provides valuable insight into the biological mechanisms of complex diseases at the post-transcriptional level.Although a variety of identification algorithms have been proposed recently,most of them capture the features of m6A modification sites by focusing on the sequential dependencies of nucleotides at different positions in RNA sequences,while ignoring the structural dependencies of nucleotides in their threedimensional structures.To overcome this issue,we propose a cross-species end-to-end deep learning model,namely CR-NSSD,which conduct a cross-domain representation learning process integrating nucleotide structural and sequential dependencies for RNA m6A site identification.Specifically,CR-NSSD first obtains the pre-coded representations of RNA sequences by incorporating the position information into single-nucleotide states with chaos game representation theory.It then constructs a crossdomain reconstruction encoder to learn the sequential and structural dependencies between nucleotides.By minimizing the reconstruction and binary cross-entropy losses,CR-NSSD is trained to complete the task of m6A site identification.Extensive experiments have demonstrated the promising performance of CR-NSSD by comparing it with several state-of-the-art m6A identification algorithms.Moreover,the results of cross-species prediction indicate that the integration of sequential and structural dependencies allows CR-NSSD to capture general features of m6A modification sites among different species,thus improving the accuracy of cross-species identification.展开更多
BACKGROUND Through experimental research on the biological function of GATA6-AS1,it was confirmed that GATA6-AS1 can inhibit the proliferation,invasion,and migration of gastric cancer cells,suggesting that GATA6-AS1 p...BACKGROUND Through experimental research on the biological function of GATA6-AS1,it was confirmed that GATA6-AS1 can inhibit the proliferation,invasion,and migration of gastric cancer cells,suggesting that GATA6-AS1 plays a role as an anti-oncogene in the occurrence and development of gastric cancer.Further experi-ments confirmed that the overexpression of fat mass and obesity-associated protein(FTO)inhibited the expression of GATA6-AS1,thereby promoting the occurrence and development of gastric cancer.AIM To investigate the effects of GATA6-AS1 on the proliferation,invasion and migration of gastric cancer cells and its mechanism of action.METHODS We used bioinformatics methods to analyze the Cancer Genome Atlas(https://portal.gdc.cancer.gov/.The Cancer Genome Atlas)and download expression data for GATA6-AS1 in gastric cancer tissue and normal tissue.We also constructed a GATA6-AS1 lentivirus overexpression vector which was transfected into gastric cancer cells to investigate its effects on proliferation,migration and invasion,and thereby clarify the expression of GATA6-AS1 in gastric cancer and its biological role in the genesis and development of gastric cancer.Next,we used a database(http://starbase.sysu.edu.cn/starbase2/)to analysis GATA6-AS1 whether by m6A methylation modify regulation and predict the methyltransferases that may methylate GATA6-AS1.Furthermore,RNA immunoprecipitation experiments confirmed that GATA6-AS1 was able to bind to the m6A methylation modification enzyme.These data allowed us to clarify the ability of m6A methylase to influence the action of GATA6-AS1 and its role in the occurrence and development of gastric cancer.RESULTS Low expression levels of GATA6-AS1 were detected in gastric cancer.We also determined the effects of GATA6-AS1 overexpression on the biological function of gastric cancer cells.GATA6-AS1 had strong binding ability with the m6A demethylase FTO,which was expressed at high levels in gastric cancer and negatively correlated with the expression of GATA6-AS1.Following transfection with siRNA to knock down the expression of FTO,the expression levels of GATA6-AS1 were up-regulated.Finally,the proliferation,migration and invasion of gastric cancer cells were all inhibited following the knockdown of FTO expression.CONCLUSION During the occurrence and development of gastric cancer,the overexpression of FTO may inhibit the expression of GATA6-AS1,thus promoting the proliferation and metastasis of gastric cancer.展开更多
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 mRNA...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.展开更多
A novel lysozyme named β-1, 4-N, 6-O-diacetylmuramidase R2 was purified and characterized from Streptomyces griseus. The molecular weight of the enzyme was determined by MALDI-TOF-MS as 23.5 kDa. The N-terminal amino...A novel lysozyme named β-1, 4-N, 6-O-diacetylmuramidase R2 was purified and characterized from Streptomyces griseus. The molecular weight of the enzyme was determined by MALDI-TOF-MS as 23.5 kDa. The N-terminal amino acid sequence was DTSGVQGIDVSHWQG. Chemical modification of β-1, 4-N, 6-O-diacetylmuramidase R2 indicated that sulfhydryl group and carbamidine of arginine residues are not essential for the activity of the enzyme, but lysine residues and imidazole of histidine residues are essential for the activity. The number of essential tryptophan and carboxyl groups was found that only one tryptophan residue and three carboxyl groups in the active site.展开更多
N^(6)-methyladenosine(m^(6)A)RNA modification is widely perceived as the most abundant and common modification in transcripts.This modification is dynamically regulated by specific m^(6)A“writers”,“erasers”and“re...N^(6)-methyladenosine(m^(6)A)RNA modification is widely perceived as the most abundant and common modification in transcripts.This modification is dynamically regulated by specific m^(6)A“writers”,“erasers”and“readers”and is reportedly involved in the occurrence and development of many diseases.Since m^(6)A RNA modification was discovered in the 1970s,with the progress of relevant research technologies,an increasing number of functions of m^(6)A have been reported,and a preliminary understanding of m^(6)A has been obtained.In this review,we summarize the mechanisms through which m^(6)A RNA modification is regulated from the perspectives of expression,posttranslational modification and protein interaction.In addition,we also summarize how external and internal environmental factors affect m^(6)A RNA modification and its functions in tumors.The mechanisms through which m^(6)A methylases,m^(6)A demethylases and m^(6)A-binding proteins are regulated are complicated and have not been fully elucidated.Therefore,we hope to promote further research in this field by summarizing these mechanisms and look forward to the future application of m^(6)A in tumors.展开更多
基金Key Project Research and Development Plan of Hainan Province(No.ZDYF2020134,ZDYF2022SHFZ283)Natural Science Foundation of Hainan Province(No.821QN391)。
文摘N6-methyladenosine(m6A)is a reversible epigenetic modification, which is one of the most abundant modifiers in eukaryotic cells and has been commonly reported in messenger RNAs and non-coding RNAs. The processing modification of m6A regulates RNA transcription, processing, splicing, degradation, and translation, and plays an important role in the biological process of tumors. Circular RNA, which lacks the 5' cap structure, has been mistakenly regarded as a "junk sequence" generated by accidental shearing during the transcription process. However, it has been found that circRNAs can be involved in tumor invasion and metastasis through microRNAs, binding proteins, translated peptides, and m6A modifications. In this paper, we reviewed the role of m6A modifications in circRNA regulation and their functions in hepatocellular carcinoma and discussed their potential clinical applications and future development in this field.
基金Supported by Project of Shanghai Science and Technology (No.20ZR1443600)。
文摘N6-methyladenosine(m6A)modification is a reversible process promoted by“writers”,inhibited by“erasers”,and processed by“readers”.During the last decade,increasing emphasis has been placed on the underlying roles of m6A modification owing to their great importance in biological significance.The abnormal regulation of m6A modification will lead to aberrant cellular behavior and various diseases.Recently,studies have demonstrated that m6A modification is closely associated with the genesis and progression of ocular surface diseases(OSDs).This review focus on the role of m6A modification and research progress in OSDs including fungal keratitis,herpes simplex keratitis,immunerelated keratoconjunctival diseases,pterygium,ocular chemical burns,and Graves’ophthalmopathy,which may provide new insights into and prospective applications for OSDs.
基金Supported by the National Natural Science Foundation of China(No.82171069No.82371070)+3 种基金Shanghai Science and Technology Committee(No.22015820200)Shanghai Municipal Health Commission Innovative Medical Device Application Demonstration Project(No.23SHS03500-03)Project of Shanghai Municipal Commission of Health and Family Planning(No.202140224)Grants from Interdisciplinary Program of Shanghai Jiao Tong University(No.YG2021QN52).
文摘AIM:To characterize the N6-methyladenosine(m6A)modification patterns in long non-coding RNAs(lncRNAs)in sporadic congenital cataract(CC)and age-related cataract(ARC).METHODS:Anterior capsule of the lens were collected from patients with CC and ARC.Methylated RNA immunoprecipitation with next-generation sequencing and RNA sequencing were performed to identify m6A-tagged lncRNAs and lncRNAs expression.Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses and Gene Ontology annotation were used to predict potential functions of the m6A-lncRNAs.RESULTS:Large amount of m6A peaks within lncRNA were identified for both CC and ARC,while the level was much higher in ARC(49870 peaks)than that in CC(18688 peaks),yet those difference between ARC in younger age group(ARC-1)and ARC in elder age group(ARC-2)was quite slight.A total of 1305 hypermethylated and 1178 hypomethylated lncRNAs,as well as 182 differential expressed lncRNAs were exhibited in ARC compared with CC.On the other hand,5893 hypermethylated and 5213 hypomethylated lncRNAs,as well as 155 significantly altered lncRNA were identified in ARC-2 compared with ARC-1.Altered lncRNAs in ARC were mainly associated with the organization and biogenesis of intracellular organelles,as well as nucleotide excision repair.CONCLUSION:Our results for the first time present an overview of the m6A methylomes of lncRNA in CC and ARC,providing a solid basis and uncovering a new insight to reveal the potential pathogenic mechanism of CC and ARC.
基金supported in part by the National Natural Science Foundation of China(62373348)the Natural Science Foundation of Xinjiang Uygur Autonomous Region(2021D01D05)+1 种基金the Tianshan Talent Training Program(2023TSYCLJ0021)the Pioneer Hundred Talents Program of Chinese Academy of Sciences.
文摘N6-methyladenosine(m6A)is an important RNA methylation modification involved in regulating diverse biological processes across multiple species.Hence,the identification of m6A modification sites provides valuable insight into the biological mechanisms of complex diseases at the post-transcriptional level.Although a variety of identification algorithms have been proposed recently,most of them capture the features of m6A modification sites by focusing on the sequential dependencies of nucleotides at different positions in RNA sequences,while ignoring the structural dependencies of nucleotides in their threedimensional structures.To overcome this issue,we propose a cross-species end-to-end deep learning model,namely CR-NSSD,which conduct a cross-domain representation learning process integrating nucleotide structural and sequential dependencies for RNA m6A site identification.Specifically,CR-NSSD first obtains the pre-coded representations of RNA sequences by incorporating the position information into single-nucleotide states with chaos game representation theory.It then constructs a crossdomain reconstruction encoder to learn the sequential and structural dependencies between nucleotides.By minimizing the reconstruction and binary cross-entropy losses,CR-NSSD is trained to complete the task of m6A site identification.Extensive experiments have demonstrated the promising performance of CR-NSSD by comparing it with several state-of-the-art m6A identification algorithms.Moreover,the results of cross-species prediction indicate that the integration of sequential and structural dependencies allows CR-NSSD to capture general features of m6A modification sites among different species,thus improving the accuracy of cross-species identification.
基金Natural Science Foundation of Shandong Province,No.ZR2020MH207 and No.ZR2020MH251.
文摘BACKGROUND Through experimental research on the biological function of GATA6-AS1,it was confirmed that GATA6-AS1 can inhibit the proliferation,invasion,and migration of gastric cancer cells,suggesting that GATA6-AS1 plays a role as an anti-oncogene in the occurrence and development of gastric cancer.Further experi-ments confirmed that the overexpression of fat mass and obesity-associated protein(FTO)inhibited the expression of GATA6-AS1,thereby promoting the occurrence and development of gastric cancer.AIM To investigate the effects of GATA6-AS1 on the proliferation,invasion and migration of gastric cancer cells and its mechanism of action.METHODS We used bioinformatics methods to analyze the Cancer Genome Atlas(https://portal.gdc.cancer.gov/.The Cancer Genome Atlas)and download expression data for GATA6-AS1 in gastric cancer tissue and normal tissue.We also constructed a GATA6-AS1 lentivirus overexpression vector which was transfected into gastric cancer cells to investigate its effects on proliferation,migration and invasion,and thereby clarify the expression of GATA6-AS1 in gastric cancer and its biological role in the genesis and development of gastric cancer.Next,we used a database(http://starbase.sysu.edu.cn/starbase2/)to analysis GATA6-AS1 whether by m6A methylation modify regulation and predict the methyltransferases that may methylate GATA6-AS1.Furthermore,RNA immunoprecipitation experiments confirmed that GATA6-AS1 was able to bind to the m6A methylation modification enzyme.These data allowed us to clarify the ability of m6A methylase to influence the action of GATA6-AS1 and its role in the occurrence and development of gastric cancer.RESULTS Low expression levels of GATA6-AS1 were detected in gastric cancer.We also determined the effects of GATA6-AS1 overexpression on the biological function of gastric cancer cells.GATA6-AS1 had strong binding ability with the m6A demethylase FTO,which was expressed at high levels in gastric cancer and negatively correlated with the expression of GATA6-AS1.Following transfection with siRNA to knock down the expression of FTO,the expression levels of GATA6-AS1 were up-regulated.Finally,the proliferation,migration and invasion of gastric cancer cells were all inhibited following the knockdown of FTO expression.CONCLUSION During the occurrence and development of gastric cancer,the overexpression of FTO may inhibit the expression of GATA6-AS1,thus promoting the proliferation and metastasis of gastric cancer.
基金funded by Notingham University and the Neuroscience Support Group Charity,UK(to HMK)supported by a CONACYT PhD scholarshipMD?was supported by the Postdoctoral Research Fellowship Program of TUBITAK。
文摘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.
基金The authors were grateful to the National Natural Science Foundation of China(No.30470050)Natural Science Foundation of Shandong Province(No.z2005d02)for financial support,
文摘A novel lysozyme named β-1, 4-N, 6-O-diacetylmuramidase R2 was purified and characterized from Streptomyces griseus. The molecular weight of the enzyme was determined by MALDI-TOF-MS as 23.5 kDa. The N-terminal amino acid sequence was DTSGVQGIDVSHWQG. Chemical modification of β-1, 4-N, 6-O-diacetylmuramidase R2 indicated that sulfhydryl group and carbamidine of arginine residues are not essential for the activity of the enzyme, but lysine residues and imidazole of histidine residues are essential for the activity. The number of essential tryptophan and carboxyl groups was found that only one tryptophan residue and three carboxyl groups in the active site.
基金supported by the Research Project of Jiangsu Commission of Health(China)(No.K2019019).
文摘N^(6)-methyladenosine(m^(6)A)RNA modification is widely perceived as the most abundant and common modification in transcripts.This modification is dynamically regulated by specific m^(6)A“writers”,“erasers”and“readers”and is reportedly involved in the occurrence and development of many diseases.Since m^(6)A RNA modification was discovered in the 1970s,with the progress of relevant research technologies,an increasing number of functions of m^(6)A have been reported,and a preliminary understanding of m^(6)A has been obtained.In this review,we summarize the mechanisms through which m^(6)A RNA modification is regulated from the perspectives of expression,posttranslational modification and protein interaction.In addition,we also summarize how external and internal environmental factors affect m^(6)A RNA modification and its functions in tumors.The mechanisms through which m^(6)A methylases,m^(6)A demethylases and m^(6)A-binding proteins are regulated are complicated and have not been fully elucidated.Therefore,we hope to promote further research in this field by summarizing these mechanisms and look forward to the future application of m^(6)A in tumors.
