Yang Liping, Chen Shengchuan, Xia Jingyan, Zhou Ying, Peng Linan, Fan Huimin, Han Yu, Duan Lihua, Cheng Genhong, Yang Heng, Xu Feng
Department of Infectious Diseases, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China.
Institute of Systems Medicine, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100005, China.
Cell Biosci. 2022 Jun 3;12(1):81. doi: 10.1186/s13578-022-00814-6.
As important enzymes regulating acetylation, histone deacetylases (HDACs) participate in a series of cell physiological process. However, the mechanisms responsible for individual HDAC family members in regulating innate immunity remained to be elucidated. Here we sought to reveal the mechanism of HDAC3 in regulating the inflammatory response of macrophages.
RNAseq was done to detect the transcriptional influence of HDAC3 on macrophages. Kyoto Encyclopedia of Genes and Genomes was used to reveal the change of signaling pathways after HDAC3 knockout. CHIPseq was done to detect the deacetylation modification of HDAC3 on chromosome. Western blot, immunofluorescence, and real-time quantitative PCR were used to measure the change of genes and proteins' levels. Mice were intratracheal instillation with lipopolysaccharide or Pseudomonas aeruginosa to determine the influence of HDAC3 on inflammatory response in vivo.
HDAC3-deficient macrophages had increased expression of cathepsins resulting from elevated histone acetylation. Over-expressed cathepsins such as cathepsin B (CTSB) caused remarkable degradation of receptor (TNFRSF)-interacting serine-threonine kinase 1 (RIP1), which reduced TNFα mediated NF-κB activation and inflammatory response. Consistently, mice with macrophage specific knockout of HDAC3 were impaired in inflammatory response and thereby susceptible to Pseudomonas aeruginosa infection.
HDAC3 was required for protecting RIP1 from degrading by CTSB in macrophages. Decreased RIP1 in HDAC3 knockout macrophages impaired TNFα mediated NF-κB activation. Our studies uncovered important roles of HDAC3 in the regulation of cathepsin-mediated lysosomal degradation and RIP1-mediated inflammatory response in macrophages as well as in host defense against bacterial infection.
组蛋白去乙酰化酶（HDACs）作为调节乙酰化的重要酶类，参与一系列细胞生理过程。然而，HDAC家族各成员在调节固有免疫中的作用机制仍有待阐明。在此，我们试图揭示HDAC3调节巨噬细胞炎症反应的机制。
进行RNA测序以检测HDAC3对巨噬细胞的转录影响。利用京都基因与基因组百科全书来揭示HDAC3基因敲除后信号通路的变化。进行染色质免疫沉淀测序以检测HDAC3在染色体上的去乙酰化修饰。采用蛋白质免疫印迹法、免疫荧光法和实时定量聚合酶链反应来检测基因和蛋白质水平的变化。通过气管内滴注脂多糖或铜绿假单胞菌来测定HDAC3对小鼠体内炎症反应的影响。
HDAC3缺陷型巨噬细胞中，由于组蛋白乙酰化增加，组织蛋白酶的表达升高。组织蛋白酶B（CTSB）等过表达的组织蛋白酶导致受体相互作用丝氨酸/苏氨酸激酶1（RIP1）显著降解，从而减少肿瘤坏死因子α（TNFα）介导的核因子κB（NF-κB）激活和炎症反应。同样，巨噬细胞特异性敲除HDAC3的小鼠炎症反应受损，因此易受铜绿假单胞菌感染。
HDAC3对于保护巨噬细胞中的RIP1不被CTSB降解是必需的。HDAC3基因敲除的巨噬细胞中RIP1减少，损害了TNFα介导的NF-κB激活。我们的研究揭示了HDAC3在调节巨噬细胞中组织蛋白酶介导的溶酶体降解和RIP1介导的炎症反应以及宿主抗细菌感染防御中的重要作用。
