Mislocalization of Runt-related transcription factor 3 results in airway inflammation and airway hyper-responsiveness in a murine asthma model

Decoding bronchopulmonary dysplasia in premature infants through an epigenetic lens

This review provides a comprehensive overview of the evolving insights into the epigenetic mechanisms associated with bronchopulmonary dysplasia (BPD). It specifically highlights the roles of DNA methylation, histone modifications, and RNA regulation in the development of BPD in premature infants. BPD results from complex interactions among genetic factors, environmental exposures, and neonatal stressors. Key findings suggest that intrauterine hypoxia, hyperoxia, and nutrition can lead to epigenetic alterations, affecting gene expression and methylation, which may serve as biomarkers for early BPD detection. RUNX3 is identified as a critical transcription factor influencing lung development and inflammation, while changes in DNA methylation and histone dynamics in cord blood are linked to immune dysregulation associated with BPD. The role of m6A RNA methylation regulators from the IGF2BP family affects mRNA stability and gene expression relevant to BPD. Additionally, specific histones and microRNAs, particularly from the miR-17∼92 cluster, are implicated in pulmonary development and vascular regulation. Long non-coding RNAs (lncRNAs), such as MALAT1, also play a role in gene regulation via competitive endogenous RNA networks, indicating their potential as biomarkers and therapeutic targets. The interplay of these epigenetic mechanisms underscores the need for further research to develop targeted interventions aimed at reducing BPD severity and enhancing health outcomes for at-risk neonates.

Safranal restores RUNX3-mediated immunoregulation by inhibiting the NLRP3 inflammasome in allergic asthma

Safranal is an active ingredient with pharmacological anti-inflammatory effects derived from Crocus sativus essential oil. To explore the comprehensive effects of Safranal on airway inflammation, airway hyperreactivity, and remodeling and its potential mechanisms through the allergic asthma model, an in vitro model of ASMC cells stimulated by TNF-α was established. The cells were transfected with si-RUNX3 and RUNX3 overexpression plasmids, and DEX was used as a positive control. The expression of RUNX3 was detected by western blot and immunofluorescence. The levels of inflammatory factors were measured by ELISA, while flow cytometry detected the anti-apoptotic effects and ROS production. Subsequently, OVA-sensitized WT mice and RUNX3-KO mice were administered with DEX and Safranal for 2 weeks to establish a mouse model of allergic asthma, and changes in airway hyperresponsiveness, inflammatory manifestations, and airway remodeling were detected. The mechanism of Safranal was verified by detecting the expression of RUNX3, inflammation, and fibrosis-related proteins in the lung tissues. By modulating the NLRP3/Caspase-1 pathway, Safranal significantly alleviated the negative effects caused by RUNX3 suppression in vivo and in vitro. We propose that Safranal is a potential active compound for the treatment of asthma, and its clinical application value in allergic asthma should be further explored.

SLAMF7 is a key molecule that promotes M1 polarization in lung tissue macrophages of high-fat diet-fed asthma mice model

OBJECTIVE

Investigating the regulatory role of Signaling lymphocyte activation molecule family 7 (SLAMF7) in the pathogenesis of asthma in a high fat-fed (HFD) mouse model, providing targets for treating obese asthma.

METHODS

We constructed a mouse model of obese asthma, and Quantitative real-time RT-PCR (qPCR) for the detection of mRNA levels of SLAMF7 and M1 polarization markers of macrophages. Lung tissue levels of SLAMF7 protein, macrophage M1 polarization markers, and neutrophil markers were measured by Western blotting. The proportions of SLAMF7+ macrophages and neutrophils in bronchoalveolar lavage fluid (BALF) were determined by flow cytometry. Neutrophil inflammatory cytokine levels were determined by Enzyme-linked immunosorbent assay (ELISA). Immunofluorescence performed the colocalization of SLAMF7 and inducible nitric oxide synthase (iNOS). The regulation of SLAMF7 on M1 polarization of macrophages was verified by cell experiments.

RESULTS

The group of HFD asthmatic mice had more severe airway inflammation and mucus secretion. They also had higher SLAMF7 levels, airway neutrophil inflammation and M1 polarization of macrophages in lung tissue. SLAMF7 overexpression increased M1 polarization, and SLAMF7 knockdown decreased M1 polarization. The expression change of SLAMF7 affects the expression of NR4A1 and RUNX3, inhibiting NR4A1 and promoting RUNX3.

CONCLUSION

SLAMF7 expression is increased in obese asthma mice, accompanied by neutrophil infiltration and enhanced M1 polarization. SLAMF7 promotes M1 polarization may be through the NR4A1-RUNX3 axis, suppressing NR4A1, and promoting RUNX3.

Oxidative Stress-Mediated RUNX3 Mislocalization Occurs Via Jun Activation Domain-Binding Protein 1 and Histone Modification

Runt domain transcription factor 3 (RUNX3) suppresses many different cancer types and is disabled by mutations, epigenetic repression, or cytoplasmic mislocalization. In this study, we investigated whether oxidative stress is associated with RUNX3 accumulation from the nucleus to the cytoplasm in terms of histone modification. Oxidative stress elevated histone deacetylase (HDAC) level and lowered that of histone acetyltransferase. In addition, oxidative stress decreased the expression of mixed lineage leukemia (MLL), a histone methyltransferase, but increased the expression of euchromatic histone-lysine N-methyltransferase 2 (EHMT2/G9a), which is also a histone methyltransferase. Moreover, oxidative stress-induced RUNX3 phosphorylation, Src activation, and Jun activation domain-binding protein 1 (JAB1) expression were inhibited by knockdown of HDAC and G9a, restoring the nuclear localization of RUNX3 under oxidative stress. Cytoplasmic RUNX3 localization was followed by oxidative stress-induced histone modification, activated Src along with RUNX3 phosphorylation, and induction of JAB1, resulting in RUNX3 inactivation.

CD109 on Dendritic Cells Regulates Airway Hyperreactivity and Eosinophilic Airway Inflammation

Asthma is a chronic airway inflammatory disease characterized by airway hyperreactivity (AHR) and eosinophilic airway inflammation. Dendritic cells (DCs) are essential for the development of asthma via presenting allergens, causing T-helper cell type 2 (Th2) skewing and eosinophil inflammation. Recent studies have revealed that CD109, a glycosylphosphatidylinositol-anchored glycoprotein, is involved in the pathogenesis of inflammatory diseases such as rheumatoid arthritis and psoriasis. However, no study has addressed the role of CD109 in asthma. This study sought to address the role of CD109 on DCs in the development of AHR and allergic inflammation. CD109-deficient mice (CD109^-/-) were sensitized with house dust mite or ovalbumin and compared with wild-type mice for induction of AHR and allergic inflammation. CD109-deficient mice had reduced AHR and eosinophilic inflammation together with lower Th2 cytokine expression compared with wild-type mice. Interestingly, CD109 expression was induced in lung conventional DC2s (cDC2s), but not lung cDC1s, upon allergic challenge. Lung cDC2s from CD109^-/- mice had a poor ability to induce cytokine production in ex vivo DC-T cell cocultures with high expression of RUNX3 (runt-related transcription factor 3), resulting in suppression of Th2 differentiation. Adoptive transfer of bone marrow-derived CD109^-/- DCs loaded with house dust mite failed to develop AHR and eosinophilic inflammation. Finally, administration of monoclonal anti-CD109 antibody reduced airway eosinophils and significantly decreased AHR. Our results suggest the involvement of CD109 in asthma pathogenesis. CD109 is a novel therapeutic target for asthma.

Runx Transcription Factors in T Cells-What Is Beyond Thymic Development?

Runx proteins (also known as Runt-domain transcription factors) have been studied for a long time as key regulators of cellular differentiation. RUNX2 has been described as essential for osteogenesis, whereas RUNX1 and RUNX3 are known to control blood cell development during different stages of cell lineage specification. However, recent studies show evidence of complex relationships between RUNX proteins, chromatin-modifying machinery, the cytoskeleton and different transcription factors in various non-embryonic contexts, including mature T cell homeostasis, inflammation and cancer. In this review, we discuss the diversity of Runx functions in mature T helper cells, such as production of cytokines and chemokines by different CD4 T cell populations; apoptosis; and immunologic memory acquisition. We then briefly cover recent findings about the contribution of RUNX1, RUNX2 and RUNX3 to various immunologic diseases. Finally, we discuss areas that require further study to better understand the role that Runx proteins play in inflammation and immunity.

Fine particulate matter induces airway inflammation by disturbing the balance between Th1/Th2 and regulation of GATA3 and Runx3 expression in BALB/c mice

The present study aimed to examine the effects of 2.5 µm particulate matter (PM2.5) on airway inflammation and to investigate the possible underlying mechanism. Specifically, the focus was on the imbalance of T helper (Th)1/Th2 cells and the dysregulated expression of transcription factors, including trans-acting T cell-specific transcription factor 3 (GATA3), runt-related transcription factor 3 (Runx3) and T-box transcription factor TBX21 (T-bet). In this study, ambient PM2.5 was collected and analyzed, male BALB/c mice were sensitized and treated with PBS, ovalbumin (OVA), PM2.5 or OVA + PM2.5. The effects of PM2.5 alone or PM2.5 + OVA on immunopathological changes, the expression of transcription factors GATA3, Runx3 and T-bet, and the imbalance of Th1/Th2 were investigated. It was found that PM2.5 + OVA co-exposure significantly enhanced inflammatory cell infiltration, increased higher tracheal secretions in lung tissue and upregulated respiratory resistance response to acetylcholine compared with PM2.5 or OVA single exposure and control groups. In addition, higher protein and mRNA expression levels of Th2 inflammatory mediators interleukin (IL)-4, IL-5 and IL-13 in bronchoalveolar lavage fluid were observed in PM2.5 + OVA treated mice, whereas the expression levels of GATA3 and STAT6 were exhibited in mice exposed to OVA + PM2.5 compared with the OVA and PM2.5 groups. By contrast, PM2.5 exposure decreased the protein and mRNA expression levels of Th1 cytokine interferon-γ and transcription factors Runx3 and T-bet, especially among asthmatic mice, different from OVA group, PM2.5 exposure only failed to influence the expression of T-bet. To conclude, PM2.5 exposure evoked the allergic airway inflammation response, especially in the asthmatic mouse model and led to Th1/Th2 imbalance. These effects worked mainly by upregulating GATA3 and downregulating Runx3. These data suggested that Runx3 may play an important role in PM2.5-aggravated asthma in BALB/c mice.

Methylation-dependent transcriptional repression of RUNX3 by KCNQ1OT1 regulates mouse cardiac microvascular endothelial cell viability and inflammatory response following myocardial infarction

Myocardial infarction (MI) is a major contributor to death and disability throughout the world. Increasing evidence shows that long noncoding RNAs (lncRNAs) are involved in the progression of MI. Here, we hypothesized that lncRNA potassium voltage-gated channel subfamily q member 1 overlapping transcript 1 (KCNQ1OT1) could affect the development of MI via regulation of Runt-related transcription factor (RUNX)3 by methylation. Initially, by ligation of the left anterior descending coronary artery, an acute MI (AMI) mouse model was established to collect the cardiac microvascular endothelial cells (CMECs), which revealed a high KCNQ1OT1 expression and a low RUNX3 expression with its high methylation. After that, KCNQ1OT1 knockdown or RUNX3 overexpression were transduced into the CMECs in order to detect their role in CMEC proliferation, apoptosis, and inflammatory response. Moreover, we assessed their interaction with the inflammatory Notch pathway, by determining the expression of Jagged 1, Hey1, Hes1, Notch intracellular domain, and Notch1. It was observed that after KCNQ1OT1 knockdown, the proliferation of AMI-CMECs was promoted, whereas their apoptosis was inhibited, accompanied by reduced level of inflammatory factors. These trends could also be achieved by RUNX3 overexpression via the Notch pathway. Finally, the regulation of DNA methyltransferase (DNMT)1-dependent methylation in RUNX3 by KCNQ1OT1 was determined, suggesting that KCNQ1OT1 could result in down-regulated RUNX3 expression through promoted RUNX3 methylation caused by recruiting DNMT1. Overall, this study demonstrates that KCNQ1OT1 silencing inhibits RUNX3 methylation, thereby offering protection against CMEC injury and inflammatory response in AMI, which may serve as a promising target for the disease treatment. -Wang, Y., Yang, X., Jiang, A., Wang, W., Li, J., Wen, J. Methylation-dependent transcriptional repression of RUNX3 by KCNQ1OT1 regulates mouse cardiac microvascular endothelial cell viability and inflammatory response following myocardial infarction.

Methylation Landscape of RUNX3 Promoter Region as a Predictive Marker for Th1/Th2 Imbalance in Bronchiolitis

Background

The methylation status of RUNX3 promoter region, its impact on RUNX3 gene expression, and Th1/Th2 imbalance are unknown in bronchiolitis. This study aimed to explore the predictors of bronchiolitis developing into asthma.

Material/Methods

The methylation status of RUNX3 promoter was assessed using Illumina HiSeq platform method. The relative RUNX3 mRNA levels in PBMCs were measured by qRT-PCR. Serum IL-4 and IFN-γ concentrations were measured by ELISA.

Results

A series of sites with significantly higher levels of methylation as compared to their corresponding controls were identified, including 24 sites in group Ba vs. group Cn, 13 sites in group Ba vs. group Ca, 7 sites in group Ba vs. group Bn, 16 sites in group Bn vs. group Cn, 11 sites in group Ca vs. group Cn, and 23 sites in group B vs. group C; P<0.05. The relative mRNA levels in group Ba were significantly lower than those in groups Cn, Ca, Bn; P<0.05. The serum IL-4 concentrations in group Ba were significantly higher than those in group Cn; P<0.05. The serum IFN-γ concentrations in group Ba were significantly lower than those in groups Cn, Ca, Bn; P<0.05. Correlation analysis showed that differentially methylated RUNX3 promoter region sites were significantly negatively correlated with levels of relative RUNX3 mRNA and IFN-γ, and were significantly positively correlated with IL-4 levels.

Conclusions

The methylation status of RUNX3 promoter region plays a role in Th1/Th2 imbalance by silencing RUNX3 gene expression, which can serve as predictive marker for the development of bronchiolitis into asthma.

Astragalus membranaceus improves therapeutic efficacy of asthmatic children by regulating the balance of Treg/Th17 cells

Astragalus membranaceus may be a potential therapy for childhood asthma but its driving mechanism remains elusive. The main components of A. membranaceus were identified by HPLC. The children with asthma remission were divided into two combination group (control group, the combination of budesonide and terbutaline) and A. membranaceus group (treatment group, the combination of budesonide, terbutaline and A. membranaceus). The therapeutic results were compared between two groups after 3-month therapy. Porcine peripheral blood mononuclear cells (PBMCs) were isolated from venous blood by using density gradient centrifugation on percoll. The levels of FoxP3, EGF-β, IL-17 and IL-23 from PBMCs and serum IgE were measured. The relative percentage of Treg/Th17 cells was determined using flow cytometry. The main components of A. membranaceus were calycosin-7-O-glucoside, isoquercitrin, ononin, calycosin, quercetin, genistein, kaempferol, isorhamnetin and formononetin, all of which may contribute to asthma therapy. Lung function was significantly improved in the treatment group when compared with a control group (P < 0.05). The efficacy in preventing the occurrence of childhood asthma was higher in the treatment group than the control group (P < 0.05). The levels of IgE, IL-17 and IL-23 were reduced significantly in the treatment group when compared with the control group, while the levels of FoxP3 and TGF-β were increased in the treatment group when compared with the control group (P < 0.05). A. membranaceus increased the percentage of Treg cells and reduced the percentage of Th17 cells. A. membranaceus is potential natural product for improving the therapeutic efficacy of combination therapy of budesonide and terbutaline for the children with asthma remission by modulating the balance of Treg/Th17 cells.

The correlation between Runx3 and bronchial asthma

Runx3, a member of the Runt-related transcription factor family, has attracted extensive attention due to its important role in the development of immune systems, especially in the differentiation of T cells. Accumulated evidence indicated that altered expression of Runx3 regulates a variety of target genes in different tissues/cells. Studies in animal models suggested that Runx3 may regulate the development of T cell lineage including those of innate lymphoid cells, Treg cells and dendritic cells, which may contribute to the development of hypersensitivity and asthma. Specifically, Runx3 modulates Th1/Th2 balance and hence, the production of interleukins, which induce inflammatory responses. Understanding the roles and mechanisms of Runx3 in the regulation of immune function provides a basis for the design of novel preventive and treatment models for bronchial asthma. This article reviews published data from cell lines, animal models, and patients, concerning the relationship between Runx3 expression alteration and asthma. Epigenetic regulation of Runx3 by DNA hypermethylation and microRNA, and the implication of these pathways in asthma are also discussed.