DNMT1抑制对树突状细胞的表观遗传重编程减轻过敏性气道炎症中的Th2偏斜
2025/10/31
摘要
背景：过敏性哮喘由Th2极化免疫反应驱动，但树突状细胞（DC）介导的Th2偏斜背后的表观遗传机制尚不明确。
方法：使用屋尘螨（DME）诱导的小鼠哮喘模型，我们结合药理学DNMT1抑制（5-氮杂-2′-脱氧胞苷，5-azadC）、DC特异性Dnmt1消融（Dnmt1fl/fl Itgax-Cre小鼠）、染色质免疫沉淀（ChIP）、实时定量PCR（RT-qPCR）和泛素化分析，以解析DC中IL-12b和TIM4的甲基化依赖性调控。
结果：致敏增加了DNMT1在Il12b启动子区的占据，诱导高甲基化（与初始状态相比增加2.5倍，p < 0.001）并抑制IL-12b表达（减少60%，p < 0.001）。使用5-azadC抑制DNMT1或遗传性Dnmt1消融恢复了IL-12b水平（p < 0.01），减少了支气管肺泡灌洗液（BALF）中的Th2细胞因子（40–60%）、嗜酸性粒细胞（62%）和肥大细胞介质（p < 0.01），并减轻了气道炎症。IL-12b通过Trim28介导的K48连接泛素化促进TIM4降解（p < 0.01），而Il12b缺陷则维持TIM4表达和Th2极化。DNMT1在Il12b启动子区的富集与TIM4上调相关（r = 0.87，p < 0.01），形成一个自我强化的循环，该循环可被Timd4敲低破坏。
结论：DC中的DNMT1通过沉默Il12b和稳定TIM4来协调Th2极化，这使DNMT1抑制剂和TIM4靶向疗法成为重新平衡哮喘中Th1/Th2反应的新策略。
Epigenetic reprogramming of dendritic cells by DNMT1 inhibition attenuates Th2 skewing in allergic airway inflammation
J.Xue, Y. Wu, Z. Liu, S. Duan, Y. Ji, R. Dong, et al.
Abstract
BACKGROUND:Allergic asthma is driven by Th2-polarized immune responses, yet the epigenetic mechanisms underlying dendritic cell (DC)-mediated Th2 skewing remain unclear.
METHODS:Using a house dust mite (DME)-induced murine asthma model, we combined pharmacological DNMT1 inhibition (5-Aza-2′-deoxycytidine, 5-azadC), DC-specific Dnmt1 ablation (Dnmt1fl/fl Itgax-Cre mice), chromatin immunoprecipitation (ChIP), RT-qPCR, and ubiquitination assays to dissect methylation-dependent regulation of IL-12b and TIM4 in DCs.
RESULTS: Sensitization increased DNMT1 occupancy at the Il12b promoter, inducing hypermethylation (2.5-fold vs. naïve, p < 0.001) and suppressing IL-12b expression (60% reduction, p < 0.001). DNMT1 inhibition with 5-azadC or genetic Dnmt1 ablation restored IL-12b levels (p < 0.01), reduced BALF Th2 cytokines (40–60%), eosinophils (62%), and mast cell mediators (p < 0.01), and attenuated airway inflammation. IL-12b promoted TIM4 degradation via Trim28 mediated K48-linked ubiquitination (p < 0.01), while Il12b deficiency sustained TIM4 expression and Th2 polarization. DNMT1 enrichment at the Il12b promoter correlated with TIM4 upregulation (r = 0.87, p < 0.01), forming a self reinforcing loop disrupted by Timd4 knockdown.
CONCLUSION:DNMT1 in DCs orchestrates Th2 polarization via Il12b silencing and TIM4 stabilization, positioning DNMT1 inhibitors and TIM4-targeted therapies as novel strategies to rebalance Th1/Th2 responses in asthma.
背景：过敏性哮喘由Th2极化免疫反应驱动，但树突状细胞（DC）介导的Th2偏斜背后的表观遗传机制尚不明确。
方法：使用屋尘螨（DME）诱导的小鼠哮喘模型，我们结合药理学DNMT1抑制（5-氮杂-2′-脱氧胞苷，5-azadC）、DC特异性Dnmt1消融（Dnmt1fl/fl Itgax-Cre小鼠）、染色质免疫沉淀（ChIP）、实时定量PCR（RT-qPCR）和泛素化分析，以解析DC中IL-12b和TIM4的甲基化依赖性调控。
结果：致敏增加了DNMT1在Il12b启动子区的占据，诱导高甲基化（与初始状态相比增加2.5倍，p < 0.001）并抑制IL-12b表达（减少60%，p < 0.001）。使用5-azadC抑制DNMT1或遗传性Dnmt1消融恢复了IL-12b水平（p < 0.01），减少了支气管肺泡灌洗液（BALF）中的Th2细胞因子（40–60%）、嗜酸性粒细胞（62%）和肥大细胞介质（p < 0.01），并减轻了气道炎症。IL-12b通过Trim28介导的K48连接泛素化促进TIM4降解（p < 0.01），而Il12b缺陷则维持TIM4表达和Th2极化。DNMT1在Il12b启动子区的富集与TIM4上调相关（r = 0.87，p < 0.01），形成一个自我强化的循环，该循环可被Timd4敲低破坏。
结论：DC中的DNMT1通过沉默Il12b和稳定TIM4来协调Th2极化，这使DNMT1抑制剂和TIM4靶向疗法成为重新平衡哮喘中Th1/Th2反应的新策略。
（中日友好医院呼吸与危重症医学科 李春晓 摘译 林江涛 审校）
（Cell Commun Signal 2025 Vol. 23 Issue 1 Pages 459 DOI: 10.1186/s12964-025-02467-7）
（Cell Commun Signal 2025 Vol. 23 Issue 1 Pages 459 DOI: 10.1186/s12964-025-02467-7）
Epigenetic reprogramming of dendritic cells by DNMT1 inhibition attenuates Th2 skewing in allergic airway inflammation
J.Xue, Y. Wu, Z. Liu, S. Duan, Y. Ji, R. Dong, et al.
Abstract
BACKGROUND:Allergic asthma is driven by Th2-polarized immune responses, yet the epigenetic mechanisms underlying dendritic cell (DC)-mediated Th2 skewing remain unclear.
METHODS:Using a house dust mite (DME)-induced murine asthma model, we combined pharmacological DNMT1 inhibition (5-Aza-2′-deoxycytidine, 5-azadC), DC-specific Dnmt1 ablation (Dnmt1fl/fl Itgax-Cre mice), chromatin immunoprecipitation (ChIP), RT-qPCR, and ubiquitination assays to dissect methylation-dependent regulation of IL-12b and TIM4 in DCs.
RESULTS: Sensitization increased DNMT1 occupancy at the Il12b promoter, inducing hypermethylation (2.5-fold vs. naïve, p < 0.001) and suppressing IL-12b expression (60% reduction, p < 0.001). DNMT1 inhibition with 5-azadC or genetic Dnmt1 ablation restored IL-12b levels (p < 0.01), reduced BALF Th2 cytokines (40–60%), eosinophils (62%), and mast cell mediators (p < 0.01), and attenuated airway inflammation. IL-12b promoted TIM4 degradation via Trim28 mediated K48-linked ubiquitination (p < 0.01), while Il12b deficiency sustained TIM4 expression and Th2 polarization. DNMT1 enrichment at the Il12b promoter correlated with TIM4 upregulation (r = 0.87, p < 0.01), forming a self reinforcing loop disrupted by Timd4 knockdown.
CONCLUSION:DNMT1 in DCs orchestrates Th2 polarization via Il12b silencing and TIM4 stabilization, positioning DNMT1 inhibitors and TIM4-targeted therapies as novel strategies to rebalance Th1/Th2 responses in asthma.
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Linarin 通过 ALDH2 调节保护哮喘诱导的气道上皮铁死亡和炎症
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