Neutrophilic asthma is a steroid-resistant condition linked to immunometabolic dysregulation. While the NAD+-dependent deacetylase Sirtuin 6 (SIRT6) regulates immune responses, its role in neutrophilic asthma remains unknown. Utilizing multiple human samples and neutrophilic asthma murine model, we identify macrophage SIRT6 as a key regulator that governs airway neutrophil infiltration in severe asthma. Myeloid-specific Sirt6 deletion attenuates allergen-induced airway neutrophil infiltration by suppressing lactate dehydrogenase A (LDHA)-mediated lactate production and neutrophil-recruiting chemokines secretion. Mechanistically, SIRT6 directly interacts with LDHA and deacetylates LDHA at lysine 261 (K261) via SIRT6-N-terminal domain. Lactate accumulation promotes histone H4 lysine 12 (H4K12) lactylation, up-regulating Cxcl1 and Cxcl2 transcription to drive airway neutrophil infiltration. Importantly, we screen flavonoid astragalin as a specific SIRT6 inhibitor that attenuates airway neutrophil infiltration in severe asthmatic mice. Collectively, our findings reveal a critical role of the SIRT6-mediated metabolic reprogramming in neutrophilic asthma and establish SIRT6 as a promising therapeutic target.

Severe asthma frequently manifests as a neutrophilic phenotype associated with dysregulated Th17 cell response, yet the molecular mechanism regulating Th17 cell-driven pathology remain poorly defined. Here, we identified histone deacetylase (HDAC) 10 as a critical regulator of Th17 cell differentiation in severe asthma. HDAC10 expression in CD4+ T cells was upregulated in asthmatic mice and patients with asthma. CD4+ T cell-specific deletion of Hdac10 attenuated neutrophilic airway inflammation by dampening Th17 cell differentiation and subsequent IL-17A secretion. Mechanistically, HDAC10 directly bound to signal transducer and activator of transcription 3 (STAT3) and deacetylated it at lysine 631 (K631) in Th17 cells, a post-translational modification essential for Il-17a transcription and subsequent neutrophilic airway inflammation. Importantly, pharmacological inhibition of HDAC10 abrogated Th17 cell response and neutrophilic airway inflammation. Together, our findings reveal an unrecognized role for HDAC10 in governing Th17 cell pathogenicity, highlighting HDAC10 as a promising therapeutic target for severe asthma.

Chronic airway inflammation is a central driver of asthma pathogenesis, in which macrophages play a pivotal role. While autophagy is known to regulate macrophage function, the specific molecular mechanisms linking autophagy to allergic airway inflammation remain unclear. Here, we identify macrophage sirtuin 6 (SIRT6) as a critical regulator of autophagy and allergic inflammation in asthma. SIRT6 expression was elevated in lung tissues and macrophages from asthmatic mice. Myeloid-specific Sirt6 deletion attenuated allergic airway inflammation in asthma murine model. Mechanistically, SIRT6 promoted proinflammatory cytokine expression via autophagy-related 3 (ATG3)-mediated autophagy in macrophages. We further demonstrated that SIRT6 directly bound to ATG3 and deacetylated it at lysine 77 (K77), a modification required for driving the proinflammatory response. Importantly, pharmacological inhibition of SIRT6 with OSS_128167 suppressed macrophage autophagy and alleviated allergic inflammation. Our findings establish SIRT6 as a key promoter of allergic airway inflammation through ATG3 deacetylation and enhanced autophagy in macrophages, highlighting SIRT6 inhibition as a potential novel therapeutic strategy for asthma.

The differential diagnosis of tuberculous pleural effusion (TPE) and lung adenocarcinoma-associated malignant pleural effusion (LA-MPE) remains challenging. This study aimed to measure interleukin‑9 (IL‑9) levels in pleural fluid and evaluate its diagnostic utility in distinguishing between these two conditions. The study enrolled 105 patients with PE (51 TPE and 54 LA-MPE). IL-9 levels in pleural fluid were measured by enzyme-linked immunosorbent assay (ELISA). Receiver operating characteristic (ROC) curve analysis was employed to identify the optimal cutoff value and assess diagnostic performance, including area under the curve (AUC), sensitivity, and specificity, with adenosine deaminase (ADA) and carcinoembryonic antigen (CEA) as comparators. Internal cross-validation was conducted to examine model robustness, and decision curve analysis was used to evaluate the clinical net benefit of IL-9 alone and in combination with ADA and CEA. IL-9 levels were significantly elevated in TPE compared with LA-MPE (2828.13 vs. 310.55 ng/L, P < 0.001). At a cutoff of 748.47 ng/L, IL-9 distinguished TPE from LA-MPE with a sensitivity of 98.0

Dysregulated macrophage polarization is a pivotal driver of airway inflammation in asthma, yet the underlying molecular mechanisms remain incompletely understood. Here, we demonstrate that histone acetyltransferase KAT8 exacerbates allergic airway inflammation by promoting M2 macrophage polarization in asthma. KAT8 expression was significantly upregulated in lung macrophages of asthmatic mice and in bone marrow-derived macrophages (BMDMs) stimulated with house dust mite (HDM). Macrophage-specific KAT8 deficiency attenuated allergic airway inflammation and inhibited M2 macrophage polarization by suppressing signal transducer and activator of transcription 3 (STAT3) signaling. Mechanistically, KAT8 directly interacted with STAT3 and targeted it for acetylation, thereby driving M2 macrophage polarization. Importantly, pharmacological inhibition of KAT8 reduced M2 macrophage polarization and attenuated allergic airway inflammation. These findings establish KAT8 as a critical regulator of macrophage-driven allergic inflammation via STAT3 acetylation, highlighting its potential as a therapeutic target for asthma.

Macrophages play central role in driving airway inflammation during asthma pathogenesis, though the molecular mechanism governing their function remains incompletely understood. Here, we demonstrate that lysine acetyltransferase 8 (KAT8) plays a critical role in papain-induced neutrophilic airway inflammation through post-translational modification of poly(C)-binding protein 1 (PCBP1). We show that papain exposure significantly upregulates KAT8 expression in lung macrophages both in vivo and in vitro. Myeloid-specific Kat8 deficiency conferred protection against papain-induced airway inflammation, reducing CXCL1 and CXCL2 production and consequent neutrophil recruitment. Mechanistically, KAT8 interacted with PCBP1 via its C2HC zinc finger domain and acetylated it at lysine 119 (K119), an essential modification for CXCL1 and CXCL2 secretion. Moreover, KAT8 enhanced M1 macrophage polarization in papain-exposed mice. Importantly, pharmacological inhibition of KAT8 significantly attenuated neutrophil infiltration and allergic airway inflammation in vivo. Our findings establish KAT8 as a pivotal regulator of neutrophilic airway inflammation through PCBP1 acetylation and highlight the KAT8-PCBP1 axis as a promising therapeutic target for severe asthma.

Exposure to fine particulate matter (PM2.5) represents a leading environmental cause of pulmonary inflammation and diseases, yet the underlying cellular mechanisms remain incompletely understood. Here, we identify histone deacetylase 10 (HDAC10) in macrophages as a critical regulator of PM2.5-induced airway inflammation by governing autophagic flux. PM2.5 exposure upregulated HDAC10 expression specifically in lung macrophages both in vivo and in vitro. Myeloid-specific Hdac10 deletion markedly attenuated PM2.5-induced airway inflammation and inflammatory cytokine production by inhibiting macrophage autophagy. Mechanistically, HDAC10 interacted with Beclin1 and deacetylated it at lysine 5 (K5), a modification critical for autophagic flux and subsequent inflammatory responses. Pharmacological inhibition of HDAC10 with salvianolic acid B reduced Beclin1 deacetylation, suppressed macrophage autophagy, and ameliorated PM2.5-induced lung inflammation. Clinically, elevated HDAC10 expression and reduced Beclin1 acetylation were observed in lung tissues from chronic obstructive pulmonary disease (COPD) patients, where HDAC10 mRNA levels correlated positively with the heightened lung inflammation. Our findings reveal a previously unrecognized HDAC10-Beclin1 axis that links PM2.5 exposure to macrophage autophagy and pulmonary inflammation, providing potential therapeutic targets for PM2.5-related respiratory diseases.

Background Aberrant activation of macrophages is associated with pathogenesis of acute lung injury (ALI). However, the potential pathogenesis has not been explored. Objectives We aimed to identify whether histone deacetylase (HDAC) 10 is involved in lipopolysaccharide (LPS)-exposed ALI and reveal the underlying pathogenesis by which it promotes lung inflammation in LPS-exposed ALI via modifying P62 with deacetylation. Methods We constructed an ALI mice model stimulated with LPS to determine the positive effect of Hdac10 deficiency. Moreover, we cultured murine alveolar macrophage cell line (MH-S cells) and primary bone marrow-derived macrophages (BMDMs) to explore the pro-inflammatory activity and mechanism of HDAC10 after LPS challenge. Results HDAC10 expression was increased both in mice lung tissues and macrophage cell lines and promoted inflammatory cytokines production exposed to LPS. Hdac10 deficiency inhibited autophagy and inflammatory response after LPS stimulation. In vivo, Hdac10(fl/fl)-LysMCre mice considerably attenuated lung inflammation and inflammatory cytokines release exposed to LPS. Mechanistically, HDAC10 interacts with P62 and mediates P62 deacetylation at lysine 165 (K165), by which it promotes P62 expression and increases inflammatory cytokines production. Importantly, we identified that Salvianolic acid B (SAB), an HDAC10 inhibitor, reduces lung inflammatory response in LPS-stimulated ALI. Conclusion These results uncover a previously unknown role for HDAC10 in regulating P62 deacetylation and aggravating lung inflammation in LPS-induced ALI, implicating that targeting HDAC10 is an effective therapy for LPS-exposed ALI.

N6-methyladenosine (m6A) modification accounts for the most prevalent mRNA internal modification and has emerged as a widespread regulatory mechanism in multiple physiological processes. We address a role of methyltransferase-like protein 3 (METTL3) in neutrophil activation. METTL3 controls neutrophil release from bone marrow to circulation through surface expression of CXC chemokine receptor 2 (CXCR2) in a Toll-like receptor 4 (TLR4) signaling-dependent manner in lipopolysaccharide (LPS)-induced endotoxemia. We show that the mRNA of TLR4 is modified by m6A, exhibiting increased translation and slowed degradation simultaneously, leading to elevated protein levels of TLR4, which eventually promotes the TLR4 signaling activation of neutrophil. The reduced expression of TLR4 lowers cytokine secretion in METTL3-deleted neutrophils upon LPS stimulation through TLR4/Myd88/nuclear factor κB (NF-κB) signaling. Collectively, these data demonstrate that METTL3 modulation of TLR4 expression is a critical determinant of neutrophil activation in endotoxemia.

Steroid resistance represents a major clinical problem in the treatment of severe asthma, and therefore a better understanding of its pathogenesis is warranted. Recent studies indicated that histone deacetylase 2 (HDAC2) and interleukin 17A (IL-17A) play important roles in severe asthma. HDAC2 activity is reduced in patients with severe asthma and smoking-induced asthma, perhaps accounting for the amplified expression of inflammatory genes, which is associated with increased acetylation of glucocorticoid receptors. Neutrophilic inflammation contributes to severe asthma and may be related to T helper (Th) 17 rather than Th2 cytokines. IL-17A levels are elevated in severe asthma and correlate with the presence of neutrophils. Restoring the activity of HDAC2 or targeting the Th17 signaling pathway is a potential therapeutic approach to reverse steroid insensitivity.

Background: Perturbation of macrophage homeostasis is one of the key mechanisms of airway inflammation in asthma. However, the exact mechanisms remain poorly understood. Objectives: We sought to examine the role of histone deacetylase (HDAC) 10 as an epigenetic regulator that governs macrophage M2 program and promotes airway inflammation in asthma, and to elucidate the underlying mechanisms. Methods: Peripheral blood and airway biopsies were obtained from healthy individuals and asthmatic patients. Asthma was induced by exposure to allergen in mice with myeloid-specific deletion of Hdac10 (Hdac10fl/fl-LysMCre) mice. HDAC10 inhibitor Salvianolic acid B (SAB), STAT3 selective agonist Colivelin, and the specific PI3K/Akt activator 1,3-Dicaffeoylquinic acid (DA) were also used in asthmatic mice. For cell studies, THP1 cells, primary mouse bone marrow derived macrophage (BMDMs) were used and related signaling pathways was investigated. Results: HDAC10 expression was highly expressed by macrophages and promoted M2 macrophage activation and airway inflammation in asthmatic patients and mice. Hdac10fl/fl-LysMCre mice were protected from airway inflammation in experimental asthma model. Hdac10 deficiency significantly attenuated STAT3 expression and decreased M2 macrophage polarization following allergen exposure. Mechanistically, HDAC10 directly binds STAT3 for deacetylation in macrophages, by which it promotes STAT3 expression and activates the macrophage M2 program. Importantly, we identified SAB as a HDAC10 inhibitor that had protective effects against airway inflammation in mice. Conclusions: Our results revealed that HDAC10-STAT3 interaction governs macrophage polarization to promote airway inflammation in asthma, implicating HDAC10 as a therapeutic target.

Dysregulation of IL-17A is closely associated with airway inflammation and remodeling in severe asthma. However, the molecular mechanisms by which IL-17A is regulated remain unclear. Here we identify epithelial sirtuin 6 (SIRT6) as an epigenetic regulator that governs IL-17A pathogenicity in severe asthma. Mice with airway epithelial cell-specific deletion of Sirt6 are protected against allergen-induced airway inflammation and remodeling via inhibiting IL-17A-mediated inflammatory chemokines and mesenchymal reprogramming. Mechanistically, SIRT6 directly interacts with RORγt and mediates RORγt deacetylation at lysine 192 via its PPXY motifs. SIRT6 promotes RORγt recruitment to the IL-17A gene promoter and enhances its transcription. In severe asthma patients, high expression of SIRT6 positively correlates with airway remodeling and disease severity. SIRT6 inhibitor (OSS_128167) treatment significantly attenuates airway inflammation and remodeling in mice. Collectively, these results uncover a function for SIRT6 in regulating IL-17A pathogenicity in severe asthma, implicating SIRT6 as a potential therapeutic target for severe asthma.

目的 探讨膜联蛋白A1(Annexin A1)对肺成纤维细胞炎症反应、增殖及胶原沉积的作用.方法 分离小鼠原代肺成纤维细胞,利用不同浓度的Annexin A1干预肺成纤维细胞24h或48 h后,检测炎症因子、细胞增殖及胶原沉积表达.将C57/BL6小鼠分为对照组、Annexin A1干预组,每组6～8只.Annexin A1干预组每只小鼠气管滴注1 μg/50 μL Annexin A1重组因子,对照组每只小鼠气道滴注50 μL生理盐水,连续干预7d后取检.检测肺组织炎症因子、Ⅲ型胶原(CollagenⅢ)及气道平滑肌肌动蛋白(α-SMA)的表达.结果 与对照组比较,Annexin A1能促进肺成纤维细胞分泌IL-6、IL-8等炎症因子(均P＜0.05),促进成纤维细胞的增殖,CollagenⅢ合成和α-SMA表达增加(均P＜0.05).与对照组小鼠比较,Arnexin A1干预组小鼠的肺泡灌洗液细胞总数[(2.91±0.26)×104/mL vs.(7.03 ±0.48)×104/mL,t=7.432,P=0.008]及中性粒细胞数目明显升高[(0.12±0.04)×104/mL vs.(1.01±0.05)×104/mL,t=13.810,P＜0.001],炎症因子、胶原沉积及平滑肌表达也显著增加(均P ＜0.05).结论 Annexin A1具有诱导肺成纤维细胞的炎症反应、增殖及胶原沉积作用,提示可能在气道重构发病中起重要作用.

Background and aims: Currently, there are no definitive therapies for coronavirus disease 2019 (COVID-19). Gut microbial dysbiosis has been proved to be associated with COVID-19 severity and probiotics is an adjunctive therapy for COIVD-19. However, the potential benefit of probiotics in COVID-19 has not been studied. We aimed to assess the relationship of probiotics use with clinical outcomes in patients with COVID-19. Methods: We conducted a propensity-score matched retrospective cohort study of adult patients with COVID-19. Eligible patients received either probiotics plus standard care (probiotics group) or standard care alone (non-probiotics group). The primary outcome was the clinical improvement rate, which was compared among propensity-score matched groups and in the unmatched cohort. Secondary outcomes included the duration of viral shedding, fever, and hospital stay. Results: Among the propensity-score matched groups, probiotics use was related to clinical improvement rates (log-rank p = 0.028). This relationship was driven primarily by a shorter (days) time to clinical improvement [difference, −3 (−4 to −1), p = 0.022], reduction in duration of fever [−1.0 (−2.0 to 0.0), p = 0.025], viral shedding [−3 (−6 to −1), p < 0.001], and hospital stay [−3 (−5 to −1), p = 0.009]. Using the Cox model with time-varying exposure, use of probiotics remained independently related to better clinical improvement rate in the unmatched cohort. Conclusion: Our study suggested that probiotics use was related to improved clinical outcomes in patients with COVID-19. Further studies are required to validate the effect of probiotics in combating the COVID-19 pandemic.

目的 探讨大气细颗粒物(PM)增强香烟暴露小鼠炎症反应的机制.方法 用野生型(WT)及IL-17A基因敲除(IL-17A-/-)小鼠,按随机数字表法随机分为对照组、熏烟组、PM组、熏烟+PM组,每组6～8只.采用香烟烟雾暴露装置烟熏,气道滴注方法吸入PM,观察气道炎症反应,连续干预3个月后取检.用HE检测肺组织炎症浸润、用ELISA及RT-PCR检测肺组织炎症因子表达、免疫组化检测平滑肌表达、Masson染色观察胶原沉积及细胞流式检测分泌IL-17A的淋巴细胞类型.体外实验,用不同浓度的香烟提取物(CSE)和/或大气细微颗粒(PM)刺激人气道上皮(HBE)细胞,用IL-17A siRNA转染在HBE细胞中敲除IL-17A基因,用RT-PCR检测炎症因子表达.结果 与对照组、熏烟组及PM组比较,熏烟联合PM组小鼠肺组织炎症因子(CXCL1、TFG-β1、IL-6及IL-17A)、胶原沉积及平滑肌表达明显增高.相反,IL-17A-/-小鼠能缓解上述指标.流式细胞检测发现PM主要通过调控CD4+细胞促进IL-17A表达,增强熏烟诱导的炎症反应.在体外,CSE、PM分别干预HBE细胞均能诱导IL-6、IL-8表达,而CSE联合PM干预HBE细胞能进一步增加IL-6、IL-8表达.敲除HBE细胞IL-17A基因后,能缓解IL-6、IL-8表达.结论 PM能诱导IL-17A表达,加剧熏烟小鼠肺组织的炎症反应、胶原沉积及平滑肌增生,提示针对IL-17A信号通路靶向治疗可能对缓解PM导致的慢性阻塞性肺疾病急性加重有效.

Background We have reported that heparin-binding epidermal growth factor (HB-EGF) is increased in patients with chronic obstructive pulmonary disease (COPD) and associated with collagen deposition, but the mechanisms remain unclear. In the present study, we aimed to investigated the inflammatory cytokines secreted by bronchial epithelial cells following exposure to HB-EGF that promoted proliferation and migration of human lung fibroblast. Methods HB-EGF-induced inflammatory cytokines were assayed in two airway epithelial cells (primary human bronchial epithelial cells [HBECs] and BEAS-2B cells). Moreover, the culture supernatants derived from HB-EGF-treated HBECs and BEAS-2B cells were added to human primary lung fibroblasts. The effect of culture supernatants on proliferation and migration of fibroblasts was assessed. Results IL-8 expression was significantly increased in bronchial epithelial cells treated with HB-EGF, which was at least partially dependent on NF-kB pathways activation. HB-EGF-induced IL-8 was found to further promote lung fibroblasts proliferation and migration, and the effects were attenuated after neutralizing IL-8. Conclusions These findings suggest that HB-EGF may be involved in the pathology of airway fibrosis by induction of IL-8 from airway epithelium, subsequently causing lung fibroblasts proliferation and migration. Thus, inhibition of HBEGF and/or IL-8 production could prevent the development of airway fibrosis by modulating fibroblast activation.

Sirtuin 1 (SIRT1) is a class III histone deacetylase that exerts an anti-inflammatory effect in airway diseases. Activated macrophages play an important role in asthma. However, the roles of SIRT1 on allergic airway inflammation in macrophages remain largely unexplored. In this study, we aimed to determine the roles of SIRT1 on allergic airway inflammation in macrophages. The effect of myeloid-specific SIRT1 deletion (Sirt1fl/fl-LysMcre) on airway inflammation was assessed by using in vivo models of asthma following allergen exposure and in vitro culture of primary bone marrow–derived macrophages (BMDMs) exposed to house dust mite (HDM). We observed that Sirt1fl/fl-LysMcre mice substantially enhanced airway inflammation and mucus production in response to allergen exposure. Expression of chemokine ligand (CXCL) 2, interleukin (IL)-1β, and tumor necrosis factor (TNF)-α were reduced in BMDMs with myeloid-specific deletion of Sirt1 after stimulation of HDM. Moreover, SIRT1 suppressed the inflammatory cytokines expression in BMDMs partially via the ERK/p38 MAPK pathways. Our study demonstrated that SIRT1 suppresses the allergic airway inflammation in macrophages, and suggested that activation of SIRT1 in macrophages may represent therapeutic strategy for asthma.

OBJECTIVE:As a result of the pandemic of COVID-19, the public have been experiencing psychological distress. However, the prevalence of psychological distress during the COVID-19 pandemic remains unknown. Our objective was to evaluate the prevalence of psychological distress during COVID-19 outbreak and their risk factors, especially their internal paths and causality. METHODS:A nationwide cross-sectional survey of the prevalence of mental disorders was conducted. We used Hospital Anxiety and Depression Scale (HADS) to estimate the prevalence of anxiety and depression. The internal paths and the causality of the psychological health were analyzed using a structural equation modeling (SEM) approach. RESULTS:A total of 24,789 respondents completed the survey. We found that the overall prevalence of anxiety, depression, combination of anxiety, and depression were 51.6% (95% CI: 51.0-52.2), 47.5% (95% CI: 46.9-48.1), and 24.5% (95% CI: 24.0-25.0), respectively. The risk of psychological disorders in men was higher than that in women. The status of psychological health was different across different age groups, education levels, occupations, and income levels. The SEM analysis revealed that inadequate material supplies, low income, low education, lack of knowledge or confidence of the epidemic, and lack of exercise are major risk factors for psychological distress. CONCLUSIONS:The evidence from this survey poses serious challenges related to the high prevalence of psychological distress, but also offers strategies to deal with the mental health problems caused by the COVID-19 pandemic.

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