Background:Small RNAs(sRNAs)extensively mediate gene-specific chromatin regulation in lower organisms.As a dominant type of functional sRNAs in mature mammals,microRNAs mainly regulate gene expression at posttranscrip...Background:Small RNAs(sRNAs)extensively mediate gene-specific chromatin regulation in lower organisms.As a dominant type of functional sRNAs in mature mammals,microRNAs mainly regulate gene expression at posttranscription level in the cytoplasm.Currently,whether there exists a type of nuclear-localized sRNAs mediating gene-specific epigenetic regulation in mature mammalian cells remains largely unclear.Here,we profiled sRNAs enriched in the nucleus and investigated their function in mediating genespecific epigenetic regulation in anti-tumor immunity.Methods:We established cytoplasmic and nuclear transcriptomes of sRNAs of dendritic cells(DCs)using high-throughput sequencing.Transcription abundances of sRNAs and mRNAs were analyzed by reverse transcriptionquantitative polymerase chain reaction(RT-qPCR)assay.The associations between sRNAs and Argonaute(AGO)proteins were detected by RNA immunoprecipitation analysis.Synthesized sRNAs and locked nucleic acid(LNA)-modified sRNA inhibitors were used to screen the function of sRNAs in innate immune cells.The effect of sRNA on the enrichment of either chromatin remodeler or histone modification at the gene promoter was analyzed by chromatin immunoprecipitation(ChIP)-qPCR assay.Chromatin accessibility qPCR assay was used to detect the accessibility of gene promoters.A B16 melanomabearing mouse model was established to determine the function of sRNAs in tumor-associated macrophages(TAMs)and their effect on tumor growth.Results:We identified a new class of nucleus-localized sRNAs,named snRNA/snoRNA-derived nuclear RNAs(sdnRNAs).Some sdnRNAs were Dicerindependent and had no association with Argonaute proteins.sdnRNA-3,the most abundant Dicer-independent sdnRNAs identified in our analysis,was selected as a representative to examine the biological function of sdnRNAs.sdnRNA-3 selectively inhibited the transcription of Nos2 in macrophages during innate immune response by repressing the chromatin accessibility at Nos2 gene promoter.sdnRNA-3 promoted the enrichments of repressive chromatinremodeling regulator Mi-2βand the repressive histone modification H3K27me3 at Nos2 gene promoter.In the B16 melanoma mouse model,we found higher expression of sdnRNA-3 in M2 TAMs than M1 TAMs and DCs.Transfer of sdnRNA-3-silenced macrophages inhibited tumor growth with increased expression of inducible nitric oxide synthase(iNOS)in TAMs.Conclusions:Our results demonstrated that the sdnRNA-3 repressed the transcription of Nos2 by repressing chromatin accessibility at the promoter,providing new insights into the regulation of macrophage function in tumor immunity.展开更多
多发性肌炎(polymyositis,PM)是一种病因不明,主要损害近端横纹肌,以肌痛、肌无力、肌萎缩为主要表现的原发性炎性肌病。若伴有皮疹等皮肤表现,则称为皮肌炎(der-matomyositis,DM)。PM/DM被普遍认为是一种自身免疫性疾病,Reichlin与Arn...多发性肌炎(polymyositis,PM)是一种病因不明,主要损害近端横纹肌,以肌痛、肌无力、肌萎缩为主要表现的原发性炎性肌病。若伴有皮疹等皮肤表现,则称为皮肌炎(der-matomyositis,DM)。PM/DM被普遍认为是一种自身免疫性疾病,Reichlin与Arnett研究显示90％以上PM/DM患者体内存在着抗细胞核或抗胞浆成分的自身抗体。近年来,随着对肌炎患者自身抗体研究不断深入,人们发现了一类“肌炎特异性自身抗体(myositis specific autoantibodies,MSA)”。展开更多
基金This work was supported by the National Natural Science Foundation of China(81922032,31900660,81788101)the Young Elite Scientist Sponsorship Program by CAST(2018QNRC001).
文摘Background:Small RNAs(sRNAs)extensively mediate gene-specific chromatin regulation in lower organisms.As a dominant type of functional sRNAs in mature mammals,microRNAs mainly regulate gene expression at posttranscription level in the cytoplasm.Currently,whether there exists a type of nuclear-localized sRNAs mediating gene-specific epigenetic regulation in mature mammalian cells remains largely unclear.Here,we profiled sRNAs enriched in the nucleus and investigated their function in mediating genespecific epigenetic regulation in anti-tumor immunity.Methods:We established cytoplasmic and nuclear transcriptomes of sRNAs of dendritic cells(DCs)using high-throughput sequencing.Transcription abundances of sRNAs and mRNAs were analyzed by reverse transcriptionquantitative polymerase chain reaction(RT-qPCR)assay.The associations between sRNAs and Argonaute(AGO)proteins were detected by RNA immunoprecipitation analysis.Synthesized sRNAs and locked nucleic acid(LNA)-modified sRNA inhibitors were used to screen the function of sRNAs in innate immune cells.The effect of sRNA on the enrichment of either chromatin remodeler or histone modification at the gene promoter was analyzed by chromatin immunoprecipitation(ChIP)-qPCR assay.Chromatin accessibility qPCR assay was used to detect the accessibility of gene promoters.A B16 melanomabearing mouse model was established to determine the function of sRNAs in tumor-associated macrophages(TAMs)and their effect on tumor growth.Results:We identified a new class of nucleus-localized sRNAs,named snRNA/snoRNA-derived nuclear RNAs(sdnRNAs).Some sdnRNAs were Dicerindependent and had no association with Argonaute proteins.sdnRNA-3,the most abundant Dicer-independent sdnRNAs identified in our analysis,was selected as a representative to examine the biological function of sdnRNAs.sdnRNA-3 selectively inhibited the transcription of Nos2 in macrophages during innate immune response by repressing the chromatin accessibility at Nos2 gene promoter.sdnRNA-3 promoted the enrichments of repressive chromatinremodeling regulator Mi-2βand the repressive histone modification H3K27me3 at Nos2 gene promoter.In the B16 melanoma mouse model,we found higher expression of sdnRNA-3 in M2 TAMs than M1 TAMs and DCs.Transfer of sdnRNA-3-silenced macrophages inhibited tumor growth with increased expression of inducible nitric oxide synthase(iNOS)in TAMs.Conclusions:Our results demonstrated that the sdnRNA-3 repressed the transcription of Nos2 by repressing chromatin accessibility at the promoter,providing new insights into the regulation of macrophage function in tumor immunity.
文摘多发性肌炎(polymyositis,PM)是一种病因不明,主要损害近端横纹肌,以肌痛、肌无力、肌萎缩为主要表现的原发性炎性肌病。若伴有皮疹等皮肤表现,则称为皮肌炎(der-matomyositis,DM)。PM/DM被普遍认为是一种自身免疫性疾病,Reichlin与Arnett研究显示90％以上PM/DM患者体内存在着抗细胞核或抗胞浆成分的自身抗体。近年来,随着对肌炎患者自身抗体研究不断深入,人们发现了一类“肌炎特异性自身抗体(myositis specific autoantibodies,MSA)”。
