Background:Dendritic cells(DCs)play a pivotal role in antigen presentation and regulating adaptive immune responses in asthma pathophysiology.However,the underlying molecular mechanisms remain incompletely understood....Background:Dendritic cells(DCs)play a pivotal role in antigen presentation and regulating adaptive immune responses in asthma pathophysiology.However,the underlying molecular mechanisms remain incompletely understood.Methods:Bioinformatics analysis of the GSE27011 dataset identified differentially expressed genes associated with pediatric asthma.An ovalbumin(OVA)-induced asthma mouse model and an Rfx5 knockdown model were established.RFX5 expression was assessed in DCs from patients with asthma and asthmatic mouse lung tissues using qRT-PCR,Western blotting,and immunohistochemistry.The regulatory effects of regulatory factor X5(RFX5)on histone deacetylase 2(HDAC2),class II major histocompatibility complex transactivator(CIITA),and major histocompatibility complex class II molecules(MHC II)expression,as well as its influence on lung tissue integrity,airway resistance,cytokine profiles,and immune cell infiltration,were analyzed.Co-immunoprecipitation and chromatin immunoprecipitation assays were performed to explore the interaction between RFX5 and HDAC2.Results:During asthma progression,RFX5 expression was upregulated,while HDAC2 levels were reduced in DCs.Rfx5 knockdown significantly alleviated lung pathology and inflammation,decreased granulocyte and lymphocyte counts,and lowered levels of pro-inflammatory cytokines interleukin 6(IL-6),tumor necrosis factor-alpha(TNF-α),and interleukin-1β(IL-1β).In contrast,the expression of anti-inflammatory cytokines such as interleukin 4(IL-4),interleukin 10(IL-10),interleukin 18(IL-18),and prostaglandin E2(PGE2)was elevated,along with an increase in CIITA and MHC II gene transcription.Further analysis revealed a direct association between HDAC2 and the RFX5 promoter region.Conclusion:During asthma pathogenesis,allergens may upregulate RFX5 expression in DCs,enhancing its interaction with HDAC2,thereby alleviating the HDAC2-mediated effect.This process promotes the transcription of MHC II-associated genes and facilitates antigen presentation,ultimately driving asthma initiation and progression.This study elucidates the role of the RFX5/HDAC2 signaling pathway in the regulation of antigen presentation in pediatric asthma.展开更多
Metabolic dysfunction-associated steatohepatitis(MASH),a severe type of metabolic dysfunction-associated steatotic liver disease(MASLD),is a leading etiology of end-stage liver disease worldwide,posing significant hea...Metabolic dysfunction-associated steatohepatitis(MASH),a severe type of metabolic dysfunction-associated steatotic liver disease(MASLD),is a leading etiology of end-stage liver disease worldwide,posing significant health and economic burdens.microRNA-320(miR-320),a ubiquitously expressed and evolutionarily conserved miRNA,has been reported to regulate lipid metabolism;however,whether and how miR-320 affects MASH development remains unclear.By performing miR-320 in situ hybridization with RNAscope,we observed a notable downregulation of miR-320 in hepatocytes during MASH,correlating with disease severity.Most importantly,miR-320 downregulation in hepatocytes exacerbated MASH progression as demonstrated that hepatocyte-specific miR-320 deficient mice were more susceptible to high-fat,high-fructose,high-cholesterol diet(HFHC)or choline-deficient,amino acid-defined,high-fat diet(CDAHFD)-induced MASH compared with control littermates.Conversely,restoration of miR-320 in hepatocytes ameliorated MASH-related steatosis and fibrosis by injection of adeno-associated virus 8(AAV8)carrying miR-320 in different types of diet-induced MASH models.Mechanistic studies revealed that miR-320 specifically regulated fibroblast growth factor 1(FGF1)production in hepatocytes by inhibiting regulator factor X1(RFX1)expression.Notably,knockdown of Rfx1in hepatocytes mitigated MASH by enhancing FGF1-mediated AMPK activation.Our findings underscore the therapeutic potential of hepatic miR-320 supplementation in MASH treatment by inhibiting RFX1-mediated FGF1 suppression.展开更多
基金supported by the 2021 Jiangxi Provincial Department of Science and Technology Applied Research Cultivation Plan Project(No.20212BAG70005,Yahui Wu)2021 Science and Technology Special Project and Social Development Project in Ji’an City,Jiangxi Province(No.20211-025242,Yahui Wu).
文摘Background:Dendritic cells(DCs)play a pivotal role in antigen presentation and regulating adaptive immune responses in asthma pathophysiology.However,the underlying molecular mechanisms remain incompletely understood.Methods:Bioinformatics analysis of the GSE27011 dataset identified differentially expressed genes associated with pediatric asthma.An ovalbumin(OVA)-induced asthma mouse model and an Rfx5 knockdown model were established.RFX5 expression was assessed in DCs from patients with asthma and asthmatic mouse lung tissues using qRT-PCR,Western blotting,and immunohistochemistry.The regulatory effects of regulatory factor X5(RFX5)on histone deacetylase 2(HDAC2),class II major histocompatibility complex transactivator(CIITA),and major histocompatibility complex class II molecules(MHC II)expression,as well as its influence on lung tissue integrity,airway resistance,cytokine profiles,and immune cell infiltration,were analyzed.Co-immunoprecipitation and chromatin immunoprecipitation assays were performed to explore the interaction between RFX5 and HDAC2.Results:During asthma progression,RFX5 expression was upregulated,while HDAC2 levels were reduced in DCs.Rfx5 knockdown significantly alleviated lung pathology and inflammation,decreased granulocyte and lymphocyte counts,and lowered levels of pro-inflammatory cytokines interleukin 6(IL-6),tumor necrosis factor-alpha(TNF-α),and interleukin-1β(IL-1β).In contrast,the expression of anti-inflammatory cytokines such as interleukin 4(IL-4),interleukin 10(IL-10),interleukin 18(IL-18),and prostaglandin E2(PGE2)was elevated,along with an increase in CIITA and MHC II gene transcription.Further analysis revealed a direct association between HDAC2 and the RFX5 promoter region.Conclusion:During asthma pathogenesis,allergens may upregulate RFX5 expression in DCs,enhancing its interaction with HDAC2,thereby alleviating the HDAC2-mediated effect.This process promotes the transcription of MHC II-associated genes and facilitates antigen presentation,ultimately driving asthma initiation and progression.This study elucidates the role of the RFX5/HDAC2 signaling pathway in the regulation of antigen presentation in pediatric asthma.
基金supported by the National Natural Science Foundation of China(82300657 and 82270601)the National Key Research and Development Program of China(2023YFA1800804)the Natural Science Foundation of Shanghai(22ZR1473800,China).
文摘Metabolic dysfunction-associated steatohepatitis(MASH),a severe type of metabolic dysfunction-associated steatotic liver disease(MASLD),is a leading etiology of end-stage liver disease worldwide,posing significant health and economic burdens.microRNA-320(miR-320),a ubiquitously expressed and evolutionarily conserved miRNA,has been reported to regulate lipid metabolism;however,whether and how miR-320 affects MASH development remains unclear.By performing miR-320 in situ hybridization with RNAscope,we observed a notable downregulation of miR-320 in hepatocytes during MASH,correlating with disease severity.Most importantly,miR-320 downregulation in hepatocytes exacerbated MASH progression as demonstrated that hepatocyte-specific miR-320 deficient mice were more susceptible to high-fat,high-fructose,high-cholesterol diet(HFHC)or choline-deficient,amino acid-defined,high-fat diet(CDAHFD)-induced MASH compared with control littermates.Conversely,restoration of miR-320 in hepatocytes ameliorated MASH-related steatosis and fibrosis by injection of adeno-associated virus 8(AAV8)carrying miR-320 in different types of diet-induced MASH models.Mechanistic studies revealed that miR-320 specifically regulated fibroblast growth factor 1(FGF1)production in hepatocytes by inhibiting regulator factor X1(RFX1)expression.Notably,knockdown of Rfx1in hepatocytes mitigated MASH by enhancing FGF1-mediated AMPK activation.Our findings underscore the therapeutic potential of hepatic miR-320 supplementation in MASH treatment by inhibiting RFX1-mediated FGF1 suppression.
文摘【目的】研究转录因子RFX1对大鼠胰腺星状细胞LTC-14分泌细胞外基质(extracellular matrix,ECM)的影响,并探究其分子机制。【方法】在LTC-14细胞中过表达Flag-RFX1质粒,并加入脂多糖(lipopolysaccharide,LPS)诱导,通过western blotting检测Flag-RFX1对Toll样受体4(Toll-like receptor 4,TLR4)、髓样分化蛋白88(myeloid differentiation factor 88,MyD88)、核因子κB-p65(nuclear factorκB-p65,NF-κB-p65)、磷酸化NF-κB-p65(phosphorylation of nuclear factorκB-p65,p-NF-κB-p65)、NF-κB抑制蛋白α(inhibitor of nuclear factor kappa B alpha,IκBα)、磷酸化IκBα(phosphorylation of inhibitor of nuclear factor kappa B alpha,p-IκBα)蛋白表达的影响,ELISA检测ECM中Ⅰ型胶原蛋白(collagenⅠ,COL-Ⅰ)、Ⅲ型胶原蛋白(collagenⅢ,COL-Ⅲ)、纤连蛋白(fibronectin,FN)和肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)的分泌水平。在LTC-14细胞中浓度依赖性地过表达Flag-RFX1质粒,western blotting和ELISA实验检测上述因子的变化。【结果】LPS诱导的LTC-14细胞中TLR4、MyD88、p-NF-κB-p65、NF-κB-p65和IκBα蛋白表达水平均升高(P<0.05),p-IκBα蛋白表达水平降低(P<0.05),且Col-Ⅰ、Col-Ⅲ、FN和TNF-α的分泌水平升高(P<0.05);而过表达Flag-RFX1质粒后,LPS诱导的LTC-14细胞中上述指标表达水平均逆转(P<0.05);并且,Flag-RFX1呈浓度依赖性地下调TLR4、MyD88、NF-κB-p65和IκBα的蛋白表达,上调p-IκBα的蛋白表达水平,浓度依赖性地抑制Col-Ⅰ、Col-Ⅲ、FN和TNF-α的分泌。【结论】转录因子RFX1通过抑制TLR4/MyD88/NF-κB-p65信号通路下调胰腺星状细胞分泌的ECM中Col-Ⅰ、Col-Ⅲ、FN和TNF-α的表达水平。
