Deletion of BRCC3 ameliorates airway inflammation in asthma by inhibiting the activation of NLRP3 inflammasome.

BRCA1/BRCA2-containing complex subunit 3 (BRCC3) serves as a deubiquitinating enzyme contributing to multiple inflammation-related disorders. However, the role of BRCC3 in modulating airway inflammation in asthma has not been investigated. This study aimed to examine the role of BRCC3 in airway inflammation using a mouse model of asthma induced by ovalbumin (OVA). BRCC3 levels were found to be elevated in mice with asthma. BRCC3 knockout (KO) mice demonstrated a notable improvement in pathological changes, accompanied by reduced levels of inflammatory cell infiltration and inflammatory cytokines, compared to wild-type (WT) mice following OVA challenge. The NLRP3 inflammasome was high activated in asthmatic mice, which was restrained by BRCC3 KO, as companied by a decrease in NLRP3, ASC, cleaved Caspase-1, cleaved Gasdermin D (GSDMD), IL-1β, and IL-18. In vitro studies demonstrated BRCC3 levels increased in airway epithelial cells in response to house dust mite (HDM) stimulation, depending on the dose and duration of exposure. Silencing BRCC3 in airway epithelial cells protected against HDM-induced cell injury and inflammation, along with inhibiting the NLRP3 inflammasome and pyroptosis. Conversely, the overexpression of BRCC3 in airway epithelial cells worsened DM-induced cell injury and inflammation while also enhancing the NLRP3 inflammasome and pyroptosis. Further investigations revealed that silencing BRCC3 increased the ubiquitination of NLRP3, whereas overexpressing BRCC3 decreased it. Pharmacological inhibition of the NLRP3 inflammasome diminished the effects of BRCC3 overexpression on the inflammation and pyroptosis induced by HDM in airway epithelial cells. Overall, these findings underscore the importance of BRCC3 in the pathogenesis of asthma. Deletion of BRCC3 alleviates airway inflammation in asthma by impeding the activation of the NLRP3 inflammasome, thus indicating that BRCC3 could serve as a potential target for asthma therapy.

Wang H ，Chen Y ，Zhang J ，Wang N ，Tian T ... -  《-》

HDAC10 switches NLRP3 modification from acetylation to ubiquitination and attenuates acute inflammatory diseases.

The NOD-like receptor protein (NLRP)3 inflammasome is at the signaling hub center to instigate inflammation in response to pathogen infection or oxidative stress, and its tight control is pivotal for immune defense against infection while avoiding parallel intensive inflammatory tissue injury. Acetylation of NLRP3 is critical for the full activation of NLRP3 inflammasome, while the precise regulation of the acetylation and deacetylation circuit of NLRP3 protein remained to be fully understood. The interaction between histone deacetylase 10 (HDAC10) and NLRP3 was detected by immunoprecipitation and western blot in the HDAC10 and NLRP3 overexpressing cells. The role of HDAC10 in NLRP3 inflammasome activation was measured by immunofluorescence, real-time PCR and immunoblotting assay in peritoneal macrophages and bone marrow-derived macrophages after the stimulation with LPS and ATP. To investigate the role of HDAC10 in NLRP3-involved inflammatory diseases, the Hdac10 knockout (Hdac10-/-) mice were used to construct the LPS-induced acute endotoxemia model and folic acid-induced acute tubular necrosis model. Tissue injury level was analyzed by hematoxylin and eosin staining, and the serum level of IL-1β was measured by enzyme-linked immunosorbent assay (ELISA). The conservative analysis and immunoprecipitation assay were performed to screen the precise catalytic site regulated by HDAC10 responsible for the switching from the acetylation to ubiquitination of NLRP3. Here we demonstrated that HDAC10 directly interacted with NLRP3 and induced the deacetylation of NLRP3, thus leading to the inhibition of NLRP3 inflammasome and alleviation of NLRP3 inflammasome-mediated acute inflammatory injury. Further investigation demonstrated that HDAC10 directly induced the deacetylation of NLRP3 at K496 residue, thus switching NLRP3 acetylation to the ubiquitination modification, resulting in the proteasomal degradation of NLRP3 protein. Thus, this study identified HDAC10 as a new eraser for NLRP3 acetylation, and HDAC10 attenuated NLRP3 inflammasome involved acute inflammation via directly deacetylating NLRP3. This study indicated that HDAC10 switched NLRP3 modification from acetylation to ubiquitination and attenuated acute inflammatory diseases, thus it provided a potential therapeutic strategy for NLRP3 inflammasome-associated diseases by targeting HDAC10.

Yang M ，Qin Z ，Lin Y ，Ma D ，Sun C ，Xuan H ，Cui X ，Ma W ，Zhu X ，Han L ... -  《Cell Communication and Signaling》

BRCC3-Mediated NLRP3 Deubiquitylation Promotes Inflammasome Activation and Atherosclerosis in Tet2 Clonal Hematopoiesis.

Yalcinkaya M ，Liu W ，Thomas LA ，Olszewska M ，Xiao T ，Abramowicz S ，Papapetrou EP ，Westerterp M ，Wang N ，Tabas I ，Tall AR ... -  《-》

DMRT3-mediated lncRNA OIP5-AS1 promotes the pyroptosis of bronchial epithelial cells by binding with EIF4A3 to enhance YAP mRNA stability.

Asthma is featured by persistent airway inflammation. Long noncoding RNAs (lncRNAs) are reported to play critical roles in asthma. However, the function of Opa interacting protein 5-antisense 1 (OIP5-AS1) in pyroptosis during the development of asthma remains unexplored. The blood samples of asthma patients (n = 32) as well as the baseline characteristics of asthma patients or healthy people were collected. An in vivo model of asthma was established using house dust mites (HDM). To mimic asthma in vitro, BEAS-2B cells were treated with HDM. Cell pyroptosis and apoptosis were examined by flow cytometry. The levels of interleukin-1 beta (IL-1β) and interleukin-18 (IL-18) were detected by enzyme-linked immunosorbent assay (ELISA). The binding among messenger RNAs (mRNAs) was assessed by chromatin immunoprecipitation (ChIP), dual luciferase report assay, RNA immunoprecipitation (RIP), co-immunoprecipitation (Co-IP), and RNA pull-down assay, respectively. The cellular localization was observed by fluorescence in situ hybridization (FISH) staining. The level of OIP5-AS1 was upregulated in asthma patients. HDM induced pyroptosis and increased the levels of IL-18, IL-1β, and lactate dehydrogenase (LDH) in BEAS-2B cells, which was obviously reversed by OIP5-AS1 knockdown. Consistently, the expressions of NOD-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), c-caspase 1, and pyroptosis-related gasdermin D-1 (GSDMD-1) in BEAS-2B cells were upregulated by HDM treatment, while these phenomena were partially abolished by silencing of OIP5-AS1. Moreover, HDM promoted the progression of asthma in vivo, which was rescued by the downregulation of OIP5-AS1. OIP5-AS1 silencing decreased HDM-induced cell pyroptosis by inactivation of NLRP3. More importantly, OIP5-AS1 promoted the mRNA stability of yes-associated protein (YAP) via binding with eukaryotic translation initiation factor 4A3 (EIF4A3), and OIP5-AS1 was transcriptionally upregulated by doublesex and mab-3 related transcription factor 3 (DMRT3). DMRT3-mediated OIP5-AS1 aggravated the progression of asthma by mediation of the EIF4A3/YAP axis, which might provide a new therapeutic strategy against asthma.

Liu Y ，Zheng Y ，Wei C ，Cai X ... -  《-》

Silencing TRIM8 alleviates allergic asthma and suppressing Th2 differentiation through inhibiting NF-κB/NLRP3 signaling pathway.

Allergic asthma is a primary type of asthma and characterized by T helper 2 (Th2) cells -mediated inflammation. Tripartite motif containing 8 (TRIM8) protein is involved in immunoreaction and inflammatory response in many diseases. However, its role in allergic asthma remains unclear. Medical databank showed that TRIM8 was increased in lung of ovalbumin (OVA)-challenged mice. This study aimed to elucidate the effects of TRIM8 on allergic asthma and Th2 development. Asthma were induced by OVA challenge in mice, and the adenovirus vector loaded with TRIM8 knockdown sequence was delivered into asthma mice by nasal inhalation. The percentage of Th2 cells in lung was assessed by flow cytometric analysis, and the contents of Th2 cytokines (interleukin (IL)-4, IL-5 and IL-13) in bronchoalveolar lavage fluid (BALF) were assessed with ELISA. In vitro Th2 induction was performed in CD4+ cells from mouse spleen, the expression of Th2 molecules (IL-4, IL-5 and GATA binding protein 3 (GATA3)) were measured by real-time PCR. In addition, the nuclear factor-kappa B (NF-κB)/nucleotide-binding oligomerization domain, leucine rich repeat and pyrin domain containing 3 (NLRP3) signaling was determined. TRIM8 was highly expressed in the lung tissues of asthmatic mice and Th2-induced CD4+ cells. OVA challenge-induced Th2 development and Th2 cytokine secretion were restrained by silencing of TRIM8 in vivo. Similarly, the Th2 differentiation in vitro was also suppressed by TRIM8 knockdown. TRIM8 inhibited the NF-κB/NLRP3 activity by blocking transforming growth factor-beta-activated kinase 1 (TAK1), and the effects of TRIM8 were abrogated by overexpression of NLRP3. Silencing TRIM8 relieved the asthmatic injury in mice and excessive Th2 development via inhibiting the NF-κB/NLRP3 pathway. It is indicated that TRIM8 may contribute to the airway inflammation in allergic asthma via activating the NF-κB/NLRP3 signaling pathway. The current study provided a novel potential target for allergic asthma treatment.

Tang Y ，Zhao Y ，Guan Y ，Xue L ，Guo J ，Zhao T ，Guan Y ，Tong S ，Che C ... -  《-》