Objective:Breast cancer is the most common malignancy in women and is characterized by a high recurrence rate that severely impacts patient survival.Regulatory T cells(Tregs)in the tumor microenvironment(TME)promote i...Objective:Breast cancer is the most common malignancy in women and is characterized by a high recurrence rate that severely impacts patient survival.Regulatory T cells(Tregs)in the tumor microenvironment(TME)promote immune evasion and metastasis,increasing recurrence risk.This study determined how the epigenetic regulators,DNMT3A and METTL7A,modulate Treg infiltration via the DDR1/STAT3/CXCL5 axis and influence breast cancer recurrence and prognosis.Methods:RNA sequencing(RNA-seq)was used to identify differentially expressed genes(DEGs),followed by Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment.Machine learning algorithms,including least absolute shrinkage and selection operator(LASSO),supported vector machine-recursive feature elimination(SVM-RFE)and ElasticNet identified DDR1 as a key gene.Validation included RT-qPCR,western blot,MSP,MeRIP-qPCR,and Co-IP to assess epigenetic regulation.Functional assays(CCK-8,Transwell,and Treg differentiation/chemotaxis)and xenograft models evaluated the role of DDR1 in tumor progression and recurrence.Results:DNMT3A upregulated DDR1 via DNA methylation,while METTL7A enhanced DDR1 mRNA stability via m6A modification.Co-regulation activated the DDR1/STAT3/CXCL5 axis,which boosted cancer cell proliferation,migration,and invasion.CXCL5 secretion increased Treg infiltration and accelerated tumor growth in vivo.DDR1 silencing reversed these effects,confirming that DDR1 has a pivotal role in breast cancer recurrence.Conclusion:DNMT3A and METTL7A were shown to cooperatively regulate DDR1 via DNA/m6A methylation,which drives Tregmediated immune suppression and recurrence.This study provided novel insights and therapeutic targets for breast cancer prognosis and treatment.展开更多
目的:探讨甲基化转移酶3(methyltransferase-like 3,METTL3)联合程序死亡配体1(programmed death ligand 1,PD-L1检测在非小细胞肺癌(non-small cell lung cancer,NSCLC)患者程序性细胞死亡蛋白1(programmed death cell protein 1,PD-1...目的:探讨甲基化转移酶3(methyltransferase-like 3,METTL3)联合程序死亡配体1(programmed death ligand 1,PD-L1检测在非小细胞肺癌(non-small cell lung cancer,NSCLC)患者程序性细胞死亡蛋白1(programmed death cell protein 1,PD-1)抑制剂治疗效果和预后预测中的价值。方法:收集NSCLC患者原发病灶组织蜡块标本,免疫组织化学检测PD-L1、METTL3的蛋白表达情况,并分析其与NSCLC患者PD-1抑制剂治疗效果和预后间的联系。结果:符合入组标准的患者共228例;其中,METTL3蛋白的表达情况与病理类型、美国东部肿瘤合作组织(Eastern American Oncology Collaborative Group,ECOG)评分、治疗方案、治疗效果以及实体瘤疗效评价标准(response evaluation criteria in solid tumors,RECIST)等因素有关;METTL3蛋白高表达患者的中位无进展生存期(progression-free-survival,PFS)为12.33个月,METTL3蛋白低或无表达患者的中位PFS为6.50个月;在接受PD-1抑制剂治疗的NSCLC患者中,METTL3蛋白高表达患者有较长的PFS;METTL3蛋白高表达患者的中位总体生存期(overall-survival,OS)为23.54个月,METTL3蛋白低或无表达患者的中位OS为20.93个月,METTL3蛋白高表达与较长的OS相关。结论:METTL3蛋白可能为预测NSCLC PD-1抑制剂免疫治疗效果的标志物。展开更多
目的探讨METTL14通过调控巨噬细胞分化抑制宫颈癌病理性发展及相关机制。方法检测宫颈癌病变样本METTL14 m RNA和蛋白,以及IL-6、iNOS、Arg-1和CD206表达变化。PMA诱导THP-1细胞转化为巨噬细胞,慢病毒过表达或抑制METTL14表达,检测IL-6...目的探讨METTL14通过调控巨噬细胞分化抑制宫颈癌病理性发展及相关机制。方法检测宫颈癌病变样本METTL14 m RNA和蛋白,以及IL-6、iNOS、Arg-1和CD206表达变化。PMA诱导THP-1细胞转化为巨噬细胞,慢病毒过表达或抑制METTL14表达,检测IL-6、iNO、Arg-1和CD206表达变化以及PI3K/AKT/GSK3β/β-catenin信号通路相关蛋白表达情况。随后加入PI3K/AKT/GSK3β/β-catenin信号通路激动剂和抑制剂,检测过表达或抑制METTL14后,巨噬细胞IL-6、iNO、Arg-1和CD206表达变化,并取其上清制成条件培养基,孵育Hela细胞,检测细胞凋亡和增殖情况。结果1)宫颈癌病变组织中METTL14 mRNA和蛋白表达降低(P<0.05),巨噬细胞M1型标志物IL-6和iNOS表达明显降低(P<0.05),而M2型标志物Arg-1和CD206表达明显升高(P<0.05)。2)巨噬细胞过表达METTL14后,IL-6和iNOS表达明显升高(P<0.05),而Arg-1和CD206表达明显降低(P<0.05),M1/M2比例升高;抑制METTL14表达后,M1型标志物降低(P<0.05),M2型标志物升高(P<0.05),M1/M2比例降低。3)巨噬细胞中转染OE-METTL14慢病毒组PI3K/AKT/GSK3β/β-catenin信号通路被抑制(P<0.05);加入PI3K/AKT激动剂后,M1型标志物降低而M2型标记物升高(P<0.05),M1/M2比例降低;OE-METTL14可逆转此趋势。Sh-METTL14慢病毒组PI3K/AKT/GSK3β/β-catenin信号通路被激活(P<0.05),加入PI3K/AKT抑制剂后,M1型标志物升高而M2型标记物降低(P<0.05),M1/M2比例升高;Sh-METTL14可逆转此趋势。4)取转染OE-METTL14慢病毒后的巨噬细胞上清培养Hela细胞,可见细胞凋亡明显增多(P<0.05),增殖明显减少(P<0.05)。Sh-METTL14组的Hela细胞则表现出细胞凋亡减少(P<0.05),增殖增多(P<0.05)。结论METTL14通过PI3K/AKT/GSK3β/β-catenin信号通路调控巨噬细胞分化可能有促进宫颈癌细胞凋亡,抑制增殖的作用。展开更多
In non-small cell lung cancer(NSCLC),the heterogeneity promotes drug resistance,and the restricted expression of programmed death-ligand 1(PD-L1)limits the immunotherapy benefits.Based on the mechanisms related to tra...In non-small cell lung cancer(NSCLC),the heterogeneity promotes drug resistance,and the restricted expression of programmed death-ligand 1(PD-L1)limits the immunotherapy benefits.Based on the mechanisms related to translation regulation and the association with PD-L1 of methyltransferaselike 3(METTL3),the novel small-molecule inhibitor STM2457 is assumed to be useful for the treatment of NSCLC.We evaluated the efficacy of STM2457 in vivo and in vitro and confirmed the effects of its inhibition on disease progression.Next,we explored the effect of STM2457 on METTL3 and revealed its effects on the inhibition of catalytic activity and upregulation of METTL3 protein expression.Importantly,we described the genome-wide characteristics of multiple omics data acquired from RNA sequencing,ribosome profiling,and methylated RNA immunoprecipitation sequencing data under STM2457 treatment or METTL3 knockout.We also constructed a model for the regulation of the translation of METTL3 and PD-L1.Finally,we found PD-L1 upregulation by STM2457 in vivo and in vitro.In conclusion,STM2457 is a potential novel suppressor based on its inhibitory effect on tumor progression and may be able to overcome the heterogeneity based on its impact on the translatome.Furthermore,it can improve the immunotherapy outcomes based on PDL1 upregulation in NSCLC.展开更多
Spinal cord injury is a severe neurological condition with limited neuronal regeneration and functional recovery.Currently,no effective treatments exist to improve spinal cord injury prognosis.Neuronal guidance protei...Spinal cord injury is a severe neurological condition with limited neuronal regeneration and functional recovery.Currently,no effective treatments exist to improve spinal cord injury prognosis.Neuronal guidance proteins are a diverse group of molecules that play crucial roles in axon and dendrite growth during nervous system development.Increasing evidence highlights their regulatory functions in spinal cord injury.This review provides a brief overview of the modulation patterns of key neuronal guidance proteins in neuronal axon growth during nervous system formation and subsequently focuses on their roles in neuronal regeneration and functional recovery following spinal cord injury.Neuronal guidance proteins include,but are not limited to,semaphorins and their receptors,plexins;netrins and their receptors,deleted in colorectal cancer and UNC5;Eph receptors and their ligands,ephrins;Slit and its receptor,Robo;repulsive guidance molecules and their receptor,neogenin;Wnt proteins and their receptor,Frizzled;and protocadherins.Localized Netrin-1 at the injury site inhibits motor axon regeneration after adult spinal cord injury while promoting oligodendrocyte growth.Slit2 enhances synapse formation in the injured spinal cord of rats.EphA7 regulates acute apoptosis in the early pathophysiological stages of spinal cord injury,while ephrinA1 plays a role in the nervous system’s injury response,with its reduced expression leading to impaired motor function in rats.EphA3 is upregulated following spinal cord injury,promoting an inhibitory environment for axonal regeneration.After spinal cord injury,bidirectional activation of ephrinB2 and EphB2 in astrocytes and fibroblasts results in the formation of a dense astrocyte-meningeal fibroblast scar.EphB1/ephrinB1 signaling mediates pain processing in spinal cord injury by regulating calpain-1 and caspase-3 in neurons.EphB3 expression increases in white matter after spinal cord injury,further inhibiting axon regeneration.Sema3A,expressed by neurons and fibroblasts in the scar surrounding the injury,inhibits motor neuron and sensory nerve growth after spinal cord injury.Sema4D suppresses neuronal axon myelination and axon regeneration,while its inhibition significantly enhances axon regeneration and motor recovery.Sema7A is involved in glial scar formation and may influence serotonin channel remodeling,thereby affecting motor coordination.Given these findings,the local or systemic application of neuronal guidance proteins represents a promising avenue for spinal cord injury treatment.展开更多
N6-methyladenosine(m^(6)A)plays crucial roles in development and cellular reprogramming.During embryonic development,pluripotency transitions from a naïve to a primed state,and modeling the reverse primed-to-na&#...N6-methyladenosine(m^(6)A)plays crucial roles in development and cellular reprogramming.During embryonic development,pluripotency transitions from a naïve to a primed state,and modeling the reverse primed-to-naïve transition(PNT)provides a valuable framework for investigating pluripotency regulation.Here,we show that inhibiting METTL3 significantly promotes PNT in an m^(6)A-dependent manner.Mechanistically,we found that suppressing METTL3 and YTHDF2 prolongs the lifetimes of pluripotency-associated mRNAs,such as Nanog and Sox2,during PNT.In addition,Gstp1 was identified as a downstream target of METTL3 inhibition and YTHDF2 knockout.Gstp1 overexpression enhances PNT,whereas its inhibition impedes the transition.Overall,our findings suggest that YTHDF2 facilitates the removal of pluripotency gene transcripts and Gstp1,thereby promoting PNT reprogramming through m^(6)A-mediated posttranscriptional control.展开更多
The development and homeostasis of intestinal epithelium are mediated by actively proliferating Lgr5^(+)stem cells,which pos-sess a remarkable self-renewal and differentiation capacity.Recently,our study demonstrated ...The development and homeostasis of intestinal epithelium are mediated by actively proliferating Lgr5^(+)stem cells,which pos-sess a remarkable self-renewal and differentiation capacity.Recently,our study demonstrated that N^(6)-methyladenosine(m^(6)A)methylation was essential for the survival of colonic stem cells.Here,we show that methyltransferase-like 3(METTL3)expression is downregulated in the colon mucosa in ulcerative colitis(UC)patients and strongly associated with the differentiation and maturation of goblet cells during inflammation.In mice,depletion of Mettl3 significantly inhibits the self-renewal and differentiation of Lgr5^(+)stem cells,especially the differentiation and maturation of goblet cells,resulting in intestinal dysplasia and spontaneous inflammation.Mechanistically,Mettl3 deletion-mediated m^(6)A loss facilitates the expression levels of growth factor receptor binding protein 10(Grb10)and interferon-related developmental regulator 1(Ifrd1)via increasing their messenger RNA stability.We further demonstrate that the levels of GRB10 and IFRD1 are negatively correlated with METTL3 level in UC samples.Collectively,our data indicate that METTL3 enhances the self-renewal and differentiation of Lgr5^(+)stem cells during intestinal development and inflammation,and thus it may be a potential therapeutic target for UC treatment.展开更多
Intestinal epithelial cells(IECs)are pivotal for maintaining intestinal homeostasis through self-renewal,proliferation,differentiation,and regulated cell death.While apoptosis and necroptosis are recognized as distinc...Intestinal epithelial cells(IECs)are pivotal for maintaining intestinal homeostasis through self-renewal,proliferation,differentiation,and regulated cell death.While apoptosis and necroptosis are recognized as distinct pathways,their intricate interplay remains elusive.In this study,we report that Mettl3-mediatedm6A modification maintains intesti-nal homeostasis by impeding epithelial cell death.Mettl3 knockout induces both apoptosis and necroptosis in IECs.Targeting different modes of cell death with specific inhibitors unveils that RIPK1 kinase activity is critical for the cell death triggered by Mettl3 knockout.Mechanistically,this occurs via them6A-mediated transcriptional regulation of Atf3,a transcription factor that directly binds to Cflar,the gene encoding the anti-cell death protein cFLIP.cFLIP inhibits RIPK1 activity,thereby suppressing downstream apoptotic and necroptotic signaling.Together,these find-ings delineate the essential role of the METTL3-ATF3-cFLIP axis in homeostatic regulation of the intestinal epithelium by blocking RIPK1 activity.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.82060479)Key Research and Development Program of Ningxia Hui Autonomous Region(Grant No.2021BEG03062)Ningxia Natural Science Fund Key Project(Grant No.2024AAC02080).
文摘Objective:Breast cancer is the most common malignancy in women and is characterized by a high recurrence rate that severely impacts patient survival.Regulatory T cells(Tregs)in the tumor microenvironment(TME)promote immune evasion and metastasis,increasing recurrence risk.This study determined how the epigenetic regulators,DNMT3A and METTL7A,modulate Treg infiltration via the DDR1/STAT3/CXCL5 axis and influence breast cancer recurrence and prognosis.Methods:RNA sequencing(RNA-seq)was used to identify differentially expressed genes(DEGs),followed by Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment.Machine learning algorithms,including least absolute shrinkage and selection operator(LASSO),supported vector machine-recursive feature elimination(SVM-RFE)and ElasticNet identified DDR1 as a key gene.Validation included RT-qPCR,western blot,MSP,MeRIP-qPCR,and Co-IP to assess epigenetic regulation.Functional assays(CCK-8,Transwell,and Treg differentiation/chemotaxis)and xenograft models evaluated the role of DDR1 in tumor progression and recurrence.Results:DNMT3A upregulated DDR1 via DNA methylation,while METTL7A enhanced DDR1 mRNA stability via m6A modification.Co-regulation activated the DDR1/STAT3/CXCL5 axis,which boosted cancer cell proliferation,migration,and invasion.CXCL5 secretion increased Treg infiltration and accelerated tumor growth in vivo.DDR1 silencing reversed these effects,confirming that DDR1 has a pivotal role in breast cancer recurrence.Conclusion:DNMT3A and METTL7A were shown to cooperatively regulate DDR1 via DNA/m6A methylation,which drives Tregmediated immune suppression and recurrence.This study provided novel insights and therapeutic targets for breast cancer prognosis and treatment.
文摘目的:探讨甲基化转移酶3(methyltransferase-like 3,METTL3)联合程序死亡配体1(programmed death ligand 1,PD-L1检测在非小细胞肺癌(non-small cell lung cancer,NSCLC)患者程序性细胞死亡蛋白1(programmed death cell protein 1,PD-1)抑制剂治疗效果和预后预测中的价值。方法:收集NSCLC患者原发病灶组织蜡块标本,免疫组织化学检测PD-L1、METTL3的蛋白表达情况,并分析其与NSCLC患者PD-1抑制剂治疗效果和预后间的联系。结果:符合入组标准的患者共228例;其中,METTL3蛋白的表达情况与病理类型、美国东部肿瘤合作组织(Eastern American Oncology Collaborative Group,ECOG)评分、治疗方案、治疗效果以及实体瘤疗效评价标准(response evaluation criteria in solid tumors,RECIST)等因素有关;METTL3蛋白高表达患者的中位无进展生存期(progression-free-survival,PFS)为12.33个月,METTL3蛋白低或无表达患者的中位PFS为6.50个月;在接受PD-1抑制剂治疗的NSCLC患者中,METTL3蛋白高表达患者有较长的PFS;METTL3蛋白高表达患者的中位总体生存期(overall-survival,OS)为23.54个月,METTL3蛋白低或无表达患者的中位OS为20.93个月,METTL3蛋白高表达与较长的OS相关。结论:METTL3蛋白可能为预测NSCLC PD-1抑制剂免疫治疗效果的标志物。
文摘目的探讨METTL14通过调控巨噬细胞分化抑制宫颈癌病理性发展及相关机制。方法检测宫颈癌病变样本METTL14 m RNA和蛋白,以及IL-6、iNOS、Arg-1和CD206表达变化。PMA诱导THP-1细胞转化为巨噬细胞,慢病毒过表达或抑制METTL14表达,检测IL-6、iNO、Arg-1和CD206表达变化以及PI3K/AKT/GSK3β/β-catenin信号通路相关蛋白表达情况。随后加入PI3K/AKT/GSK3β/β-catenin信号通路激动剂和抑制剂,检测过表达或抑制METTL14后,巨噬细胞IL-6、iNO、Arg-1和CD206表达变化,并取其上清制成条件培养基,孵育Hela细胞,检测细胞凋亡和增殖情况。结果1)宫颈癌病变组织中METTL14 mRNA和蛋白表达降低(P<0.05),巨噬细胞M1型标志物IL-6和iNOS表达明显降低(P<0.05),而M2型标志物Arg-1和CD206表达明显升高(P<0.05)。2)巨噬细胞过表达METTL14后,IL-6和iNOS表达明显升高(P<0.05),而Arg-1和CD206表达明显降低(P<0.05),M1/M2比例升高;抑制METTL14表达后,M1型标志物降低(P<0.05),M2型标志物升高(P<0.05),M1/M2比例降低。3)巨噬细胞中转染OE-METTL14慢病毒组PI3K/AKT/GSK3β/β-catenin信号通路被抑制(P<0.05);加入PI3K/AKT激动剂后,M1型标志物降低而M2型标记物升高(P<0.05),M1/M2比例降低;OE-METTL14可逆转此趋势。Sh-METTL14慢病毒组PI3K/AKT/GSK3β/β-catenin信号通路被激活(P<0.05),加入PI3K/AKT抑制剂后,M1型标志物升高而M2型标记物降低(P<0.05),M1/M2比例升高;Sh-METTL14可逆转此趋势。4)取转染OE-METTL14慢病毒后的巨噬细胞上清培养Hela细胞,可见细胞凋亡明显增多(P<0.05),增殖明显减少(P<0.05)。Sh-METTL14组的Hela细胞则表现出细胞凋亡减少(P<0.05),增殖增多(P<0.05)。结论METTL14通过PI3K/AKT/GSK3β/β-catenin信号通路调控巨噬细胞分化可能有促进宫颈癌细胞凋亡,抑制增殖的作用。
基金supported by the National Natural Science Foundation of China(Grant No.:82072593).
文摘In non-small cell lung cancer(NSCLC),the heterogeneity promotes drug resistance,and the restricted expression of programmed death-ligand 1(PD-L1)limits the immunotherapy benefits.Based on the mechanisms related to translation regulation and the association with PD-L1 of methyltransferaselike 3(METTL3),the novel small-molecule inhibitor STM2457 is assumed to be useful for the treatment of NSCLC.We evaluated the efficacy of STM2457 in vivo and in vitro and confirmed the effects of its inhibition on disease progression.Next,we explored the effect of STM2457 on METTL3 and revealed its effects on the inhibition of catalytic activity and upregulation of METTL3 protein expression.Importantly,we described the genome-wide characteristics of multiple omics data acquired from RNA sequencing,ribosome profiling,and methylated RNA immunoprecipitation sequencing data under STM2457 treatment or METTL3 knockout.We also constructed a model for the regulation of the translation of METTL3 and PD-L1.Finally,we found PD-L1 upregulation by STM2457 in vivo and in vitro.In conclusion,STM2457 is a potential novel suppressor based on its inhibitory effect on tumor progression and may be able to overcome the heterogeneity based on its impact on the translatome.Furthermore,it can improve the immunotherapy outcomes based on PDL1 upregulation in NSCLC.
基金supported by Shenzhen University General Hospital Scientific Research Project,No.SUGH2019QD002Shenzhen Science and Technology Development Foundation,No.20220810173216001(both to ZS).
文摘Spinal cord injury is a severe neurological condition with limited neuronal regeneration and functional recovery.Currently,no effective treatments exist to improve spinal cord injury prognosis.Neuronal guidance proteins are a diverse group of molecules that play crucial roles in axon and dendrite growth during nervous system development.Increasing evidence highlights their regulatory functions in spinal cord injury.This review provides a brief overview of the modulation patterns of key neuronal guidance proteins in neuronal axon growth during nervous system formation and subsequently focuses on their roles in neuronal regeneration and functional recovery following spinal cord injury.Neuronal guidance proteins include,but are not limited to,semaphorins and their receptors,plexins;netrins and their receptors,deleted in colorectal cancer and UNC5;Eph receptors and their ligands,ephrins;Slit and its receptor,Robo;repulsive guidance molecules and their receptor,neogenin;Wnt proteins and their receptor,Frizzled;and protocadherins.Localized Netrin-1 at the injury site inhibits motor axon regeneration after adult spinal cord injury while promoting oligodendrocyte growth.Slit2 enhances synapse formation in the injured spinal cord of rats.EphA7 regulates acute apoptosis in the early pathophysiological stages of spinal cord injury,while ephrinA1 plays a role in the nervous system’s injury response,with its reduced expression leading to impaired motor function in rats.EphA3 is upregulated following spinal cord injury,promoting an inhibitory environment for axonal regeneration.After spinal cord injury,bidirectional activation of ephrinB2 and EphB2 in astrocytes and fibroblasts results in the formation of a dense astrocyte-meningeal fibroblast scar.EphB1/ephrinB1 signaling mediates pain processing in spinal cord injury by regulating calpain-1 and caspase-3 in neurons.EphB3 expression increases in white matter after spinal cord injury,further inhibiting axon regeneration.Sema3A,expressed by neurons and fibroblasts in the scar surrounding the injury,inhibits motor neuron and sensory nerve growth after spinal cord injury.Sema4D suppresses neuronal axon myelination and axon regeneration,while its inhibition significantly enhances axon regeneration and motor recovery.Sema7A is involved in glial scar formation and may influence serotonin channel remodeling,thereby affecting motor coordination.Given these findings,the local or systemic application of neuronal guidance proteins represents a promising avenue for spinal cord injury treatment.
基金supported by the National Key R&D Program of China(2021YFA1102200,2024YFA1802300 and 2024YFA1107000)The National Natural Science Foundation of China(32225012)+4 种基金Major Project of Guangzhou National Laboratory(GZNL2023A02005)Guangdong Basic and Applied Basic Research Foundation(2025A1515012426,2023A1515010420)Science and Technology Projects in Guangzhou(2023A04J0724)Science and Technology Planning Project of Guangdong Province,China(2023B1212060050,2023B1212120009)Health@InnoHK Program launched by Innovation Technology Commission of the Hong Kong SAR,P.R.China.
文摘N6-methyladenosine(m^(6)A)plays crucial roles in development and cellular reprogramming.During embryonic development,pluripotency transitions from a naïve to a primed state,and modeling the reverse primed-to-naïve transition(PNT)provides a valuable framework for investigating pluripotency regulation.Here,we show that inhibiting METTL3 significantly promotes PNT in an m^(6)A-dependent manner.Mechanistically,we found that suppressing METTL3 and YTHDF2 prolongs the lifetimes of pluripotency-associated mRNAs,such as Nanog and Sox2,during PNT.In addition,Gstp1 was identified as a downstream target of METTL3 inhibition and YTHDF2 knockout.Gstp1 overexpression enhances PNT,whereas its inhibition impedes the transition.Overall,our findings suggest that YTHDF2 facilitates the removal of pluripotency gene transcripts and Gstp1,thereby promoting PNT reprogramming through m^(6)A-mediated posttranscriptional control.
基金supported by grants from the National Natural Science Foundation of China(82202017,32470951,82273214,and 82200119)the Shanghai Science and Technology Commission(22ZR1439600 and 20JC1410100)+2 种基金the Medical Talent Plan of High-level Local Universities in Shanghai(KJ3-0221-22-6338)Chongqing Medical University High-level Talent Introduction and Research Launch Fund(R2062)the Fundamental Research Funds for the Central Universities.
文摘The development and homeostasis of intestinal epithelium are mediated by actively proliferating Lgr5^(+)stem cells,which pos-sess a remarkable self-renewal and differentiation capacity.Recently,our study demonstrated that N^(6)-methyladenosine(m^(6)A)methylation was essential for the survival of colonic stem cells.Here,we show that methyltransferase-like 3(METTL3)expression is downregulated in the colon mucosa in ulcerative colitis(UC)patients and strongly associated with the differentiation and maturation of goblet cells during inflammation.In mice,depletion of Mettl3 significantly inhibits the self-renewal and differentiation of Lgr5^(+)stem cells,especially the differentiation and maturation of goblet cells,resulting in intestinal dysplasia and spontaneous inflammation.Mechanistically,Mettl3 deletion-mediated m^(6)A loss facilitates the expression levels of growth factor receptor binding protein 10(Grb10)and interferon-related developmental regulator 1(Ifrd1)via increasing their messenger RNA stability.We further demonstrate that the levels of GRB10 and IFRD1 are negatively correlated with METTL3 level in UC samples.Collectively,our data indicate that METTL3 enhances the self-renewal and differentiation of Lgr5^(+)stem cells during intestinal development and inflammation,and thus it may be a potential therapeutic target for UC treatment.
基金National Natural Science Foundation of China(31988101 to YGC,92354306 to YL)National Key Research and Development Program of China(2023YFA1800603)+2 种基金Natural Science Foundation of Jiangxi Province(20224ACB209001)Beijing Science and Technology Plan(Z231100007223006)Shenzhen Medical Research Fund(B2302022)to YGC.
文摘Intestinal epithelial cells(IECs)are pivotal for maintaining intestinal homeostasis through self-renewal,proliferation,differentiation,and regulated cell death.While apoptosis and necroptosis are recognized as distinct pathways,their intricate interplay remains elusive.In this study,we report that Mettl3-mediatedm6A modification maintains intesti-nal homeostasis by impeding epithelial cell death.Mettl3 knockout induces both apoptosis and necroptosis in IECs.Targeting different modes of cell death with specific inhibitors unveils that RIPK1 kinase activity is critical for the cell death triggered by Mettl3 knockout.Mechanistically,this occurs via them6A-mediated transcriptional regulation of Atf3,a transcription factor that directly binds to Cflar,the gene encoding the anti-cell death protein cFLIP.cFLIP inhibits RIPK1 activity,thereby suppressing downstream apoptotic and necroptotic signaling.Together,these find-ings delineate the essential role of the METTL3-ATF3-cFLIP axis in homeostatic regulation of the intestinal epithelium by blocking RIPK1 activity.
