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-met...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
Objective:Middle ear cholesteatoma is a non-tumorous condition that typically leads to hearing loss,bone destruction,and other severe complications.Despite surgery being the primary treatment,the recurrence rate remai...Objective:Middle ear cholesteatoma is a non-tumorous condition that typically leads to hearing loss,bone destruction,and other severe complications.Despite surgery being the primary treatment,the recurrence rate remains high.Therefore,exploring the molecular mechanisms underlying cholesteatoma is crucial for discovering new therapeutic approaches.This study aims to explore the involvement of N6-methyladenosine(m^(6)A)methylation in long non-coding RNAs(lncRNAs)in the biological functions and related pathways of middle ear cholesteatoma.Methods:The m^(6)A modification patterns of lncRNA in middle ear cholesteatoma tissues(n=5)and normal post-auricular skin tissues(n=5)were analyzed using an lncRNA m^(6)A transcriptome microarray.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analyses were conducted to identify potential biological functions and signaling pathways involved in the pathogenesis of middle ear cholesteatoma.Methylated RNA immunoprecipitation(MeRIP)-PCR was used to validate the m^(6)A modifications in cholesteatoma and normal skin tissues.Results:Compared with normal skin tissues,1525 lncRNAs were differentially methylated in middle ear cholesteatoma tissues,with 1048 showing hypermethylation and 477 showing hypomethylation[fold change(FC)≥3 or<1/3,P<0.05].GO enrichment analysis indicated that hypermethylated lncRNAs were involved in protein phosphatase inhibitor activity,neuron-neuron synapse,and regulation ofα-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid(AMPA)receptor activity.Hypomethylated lncRNAs were associated with mRNA methyltransferase activity,secretory granule membrane,and mRNA methylation.KEGG analysis revealed that hypermethylated lncRNAs were mainly associated with 5 pathways:the Hedgehog signaling pathway,viral protein interaction with cytokines and cytokine receptors,mitogen-activated protein kinase(MAPK)signaling pathway,cytokine-cytokine receptor interaction,and adrenergic signaling in cardiomyocytes.Hypomethylated lncRNAs were mainly involved in 4 pathways:Renal cell carcinoma,tumor necrosis factor signaling pathway,transcriptional misregulation in cancer,and cytokine-cytokine receptor interaction.Additionally,MeRIP-PCR confirmed the changes in m^(6)A methylation levels in NR_033339,NR_122111,NR_130744,and NR_026800,consistent with microarray analysis.Real-time PCR also confirmed the significant upregulation of MAPK1 and NF-κB,key genes in the MAPK signaling pathway.Conclusion:This study reveals the m^(6)A modification patterns of lncRNAs in middle ear cholesteatoma,suggests a direction for further research into the role of lncRNA m^(6)A modification in the etiology of cholesteatoma.The findings provide potential therapeutic targets for the treatment of middle ear cholesteatoma.展开更多
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 r...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.展开更多
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
Objective:To explore the effects of N6-methyladenine(m^(6)A)modification-related genes,methyltransferase 14(METTL14),and YTH domain family protein 1(YTHDF1),on the proliferation,migration and apoptosis capabilities of...Objective:To explore the effects of N6-methyladenine(m^(6)A)modification-related genes,methyltransferase 14(METTL14),and YTH domain family protein 1(YTHDF1),on the proliferation,migration and apoptosis capabilities of cervical cancer cells and investigate their correlation with programmed cell death-ligand 1(PD-L1)expression.Methods:The expression levels of METTL14,YTHDF1 and PD-L1 in cervical cancer tissues and normal cervical tissues were analyzed using immunohistochemistry.Small interfering RNA(siRNA)was used to knock down the expression of METTL14 and YTHDF1 genes in cervical cancer cells,and the knockdown efficiency was validated by real-time fluorescent quantitative PCR(qPCR).After knockdown of METTL14 and YTHDF1,cell proliferation was assessed by CCK-8 assay,cell migration was examined by Transwell assay,cell apoptosis was detected by flow cytometry,and PD-L1 mRNA and protein expression were evaluated using qPCR and Western blotting,respectively.Results:Immunohistochemistry results demonstrated high expression of METTL14,YTHDF1,and PD-L1 in cervical cancer tissues.Knockdown of METTL14 and YTHDF1 significantly inhibited the proliferation and migration capabilities of cervical cancer cells,increased apoptosis,and downregulated PD-L1 mRNA and protein expression levels.Conclusion:m^(6)A methylation modification can affect the proliferation,migration and apoptosis of cervical cancer cells by regulating the expression of PD-L1 in cervical cancer cells.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
目的:探讨RNA m^(6)A甲基化修饰在脂肪细胞胰岛素抵抗中的作用及机制。方法:收集2型糖尿病患者术中赘余皮下脂肪组织,以非2型糖尿病患者同样组织为对照,检测组间RNA m^(6)A水平。高脂饮食诱导C57BL/6J小鼠构建胰岛素抵抗(in⁃sulin resis...目的:探讨RNA m^(6)A甲基化修饰在脂肪细胞胰岛素抵抗中的作用及机制。方法:收集2型糖尿病患者术中赘余皮下脂肪组织,以非2型糖尿病患者同样组织为对照,检测组间RNA m^(6)A水平。高脂饮食诱导C57BL/6J小鼠构建胰岛素抵抗(in⁃sulin resistance,IR)模型(HFD组,n=5,60%高脂饲料喂养16周),对照组10%低脂饲料喂养16周(CD组,n=5)。模型构建成功后,取附睾周围脂肪组织行表观转录组学m^(6)A甲基化修饰芯片检测,并借助MeRIP-qPCR实验、RT-qPCR以及RNA结合蛋白免疫沉淀测定(RNA Binding Protein Immunoprecipitation Assay,RIP)实验验证胰岛素信号转导相关基因变化;进一步观察METTL3小分子抑制剂STM2457对高脂饮食诱导下小鼠胰岛素信号转导基因的影响。结果:2型糖尿病患者和小鼠IR模型脂肪组织中总体m^(6)A修饰水平均升高(患者200 ng RNA t=-8.375,P<0.001;患者100 ng RNA t=-3.722,P=0.006;患者50 ng RNA t=-4.937;P=0.001;小鼠100 ng RNA t=-3.590,P=0.023;小鼠50 ng RNA t=-2.760,P=0.025)。表观转录组学检测证实IR的脂肪组织中1175个基因发生高m^(6)A修饰,55个基因发生低m^(6)A修饰,同时有182个基因呈现高m^(6)A修饰且低表达,包括AKT2、INSR、PIK3R1、ACACA、SREBF1等5个胰岛素信号转导关键基因,其中AKT2、INSR、ACACA、SREBF1等4个基因被确证并证实其与METTL3存在直接结合,其m^(6)A修饰水平受METTL3正向调控。STM2457作用下,胰岛素敏感性提高,且AKT2、INSR、ACACA、SREBF1转录水平上调,提示IR表型改善明显。结论:高脂饮食通过METTL3诱导脂肪细胞胰岛素信号转导基因AKT2、INSR、ACACA、SREBF1发生m^(6)A高甲基化修饰,诱导其低表达,阻滞胰岛素信号转导,进而参与诱发IR。展开更多
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.
基金supported by the National Natural Science Foundation(82071036,82000973)the Natural Science Foundation of Hunan Province(2022JJ30821,2019JJ50967)the Special Project for the Construction of Innovative Provinces in Hunan Province(2023SK4030),China。
文摘Objective:Middle ear cholesteatoma is a non-tumorous condition that typically leads to hearing loss,bone destruction,and other severe complications.Despite surgery being the primary treatment,the recurrence rate remains high.Therefore,exploring the molecular mechanisms underlying cholesteatoma is crucial for discovering new therapeutic approaches.This study aims to explore the involvement of N6-methyladenosine(m^(6)A)methylation in long non-coding RNAs(lncRNAs)in the biological functions and related pathways of middle ear cholesteatoma.Methods:The m^(6)A modification patterns of lncRNA in middle ear cholesteatoma tissues(n=5)and normal post-auricular skin tissues(n=5)were analyzed using an lncRNA m^(6)A transcriptome microarray.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analyses were conducted to identify potential biological functions and signaling pathways involved in the pathogenesis of middle ear cholesteatoma.Methylated RNA immunoprecipitation(MeRIP)-PCR was used to validate the m^(6)A modifications in cholesteatoma and normal skin tissues.Results:Compared with normal skin tissues,1525 lncRNAs were differentially methylated in middle ear cholesteatoma tissues,with 1048 showing hypermethylation and 477 showing hypomethylation[fold change(FC)≥3 or<1/3,P<0.05].GO enrichment analysis indicated that hypermethylated lncRNAs were involved in protein phosphatase inhibitor activity,neuron-neuron synapse,and regulation ofα-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid(AMPA)receptor activity.Hypomethylated lncRNAs were associated with mRNA methyltransferase activity,secretory granule membrane,and mRNA methylation.KEGG analysis revealed that hypermethylated lncRNAs were mainly associated with 5 pathways:the Hedgehog signaling pathway,viral protein interaction with cytokines and cytokine receptors,mitogen-activated protein kinase(MAPK)signaling pathway,cytokine-cytokine receptor interaction,and adrenergic signaling in cardiomyocytes.Hypomethylated lncRNAs were mainly involved in 4 pathways:Renal cell carcinoma,tumor necrosis factor signaling pathway,transcriptional misregulation in cancer,and cytokine-cytokine receptor interaction.Additionally,MeRIP-PCR confirmed the changes in m^(6)A methylation levels in NR_033339,NR_122111,NR_130744,and NR_026800,consistent with microarray analysis.Real-time PCR also confirmed the significant upregulation of MAPK1 and NF-κB,key genes in the MAPK signaling pathway.Conclusion:This study reveals the m^(6)A modification patterns of lncRNAs in middle ear cholesteatoma,suggests a direction for further research into the role of lncRNA m^(6)A modification in the etiology of cholesteatoma.The findings provide potential therapeutic targets for the treatment of middle ear cholesteatoma.
基金supported by the National Natural Science Foundation of China(31902298)the Shanxi Provincial Key Research and Development Program,China(2022ZDYF126)+2 种基金the Fund for Shanxi“1331 Project”,China(20211331-13)the Science and Technology Innovation Program of Shanxi Agricultural University,China(2017YJ10)the Special Research Fund of Shanxi Agricultural University for High-level Talents,China(2021XG001)。
文摘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.
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National Natural Science Foundation of China (No.81472431)Jiangsu Provincial Medical Key Talent Fund (No.ZDRCA2016072)Natural Science Foundation of Nanjing University of Traditional Chinese Medicine (No.XZR2020070)。
文摘Objective:To explore the effects of N6-methyladenine(m^(6)A)modification-related genes,methyltransferase 14(METTL14),and YTH domain family protein 1(YTHDF1),on the proliferation,migration and apoptosis capabilities of cervical cancer cells and investigate their correlation with programmed cell death-ligand 1(PD-L1)expression.Methods:The expression levels of METTL14,YTHDF1 and PD-L1 in cervical cancer tissues and normal cervical tissues were analyzed using immunohistochemistry.Small interfering RNA(siRNA)was used to knock down the expression of METTL14 and YTHDF1 genes in cervical cancer cells,and the knockdown efficiency was validated by real-time fluorescent quantitative PCR(qPCR).After knockdown of METTL14 and YTHDF1,cell proliferation was assessed by CCK-8 assay,cell migration was examined by Transwell assay,cell apoptosis was detected by flow cytometry,and PD-L1 mRNA and protein expression were evaluated using qPCR and Western blotting,respectively.Results:Immunohistochemistry results demonstrated high expression of METTL14,YTHDF1,and PD-L1 in cervical cancer tissues.Knockdown of METTL14 and YTHDF1 significantly inhibited the proliferation and migration capabilities of cervical cancer cells,increased apoptosis,and downregulated PD-L1 mRNA and protein expression levels.Conclusion:m^(6)A methylation modification can affect the proliferation,migration and apoptosis of cervical cancer cells by regulating the expression of PD-L1 in cervical cancer cells.
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.
文摘目的:探讨RNA m^(6)A甲基化修饰在脂肪细胞胰岛素抵抗中的作用及机制。方法:收集2型糖尿病患者术中赘余皮下脂肪组织,以非2型糖尿病患者同样组织为对照,检测组间RNA m^(6)A水平。高脂饮食诱导C57BL/6J小鼠构建胰岛素抵抗(in⁃sulin resistance,IR)模型(HFD组,n=5,60%高脂饲料喂养16周),对照组10%低脂饲料喂养16周(CD组,n=5)。模型构建成功后,取附睾周围脂肪组织行表观转录组学m^(6)A甲基化修饰芯片检测,并借助MeRIP-qPCR实验、RT-qPCR以及RNA结合蛋白免疫沉淀测定(RNA Binding Protein Immunoprecipitation Assay,RIP)实验验证胰岛素信号转导相关基因变化;进一步观察METTL3小分子抑制剂STM2457对高脂饮食诱导下小鼠胰岛素信号转导基因的影响。结果:2型糖尿病患者和小鼠IR模型脂肪组织中总体m^(6)A修饰水平均升高(患者200 ng RNA t=-8.375,P<0.001;患者100 ng RNA t=-3.722,P=0.006;患者50 ng RNA t=-4.937;P=0.001;小鼠100 ng RNA t=-3.590,P=0.023;小鼠50 ng RNA t=-2.760,P=0.025)。表观转录组学检测证实IR的脂肪组织中1175个基因发生高m^(6)A修饰,55个基因发生低m^(6)A修饰,同时有182个基因呈现高m^(6)A修饰且低表达,包括AKT2、INSR、PIK3R1、ACACA、SREBF1等5个胰岛素信号转导关键基因,其中AKT2、INSR、ACACA、SREBF1等4个基因被确证并证实其与METTL3存在直接结合,其m^(6)A修饰水平受METTL3正向调控。STM2457作用下,胰岛素敏感性提高,且AKT2、INSR、ACACA、SREBF1转录水平上调,提示IR表型改善明显。结论:高脂饮食通过METTL3诱导脂肪细胞胰岛素信号转导基因AKT2、INSR、ACACA、SREBF1发生m^(6)A高甲基化修饰,诱导其低表达,阻滞胰岛素信号转导,进而参与诱发IR。
