Endothelial Sox17 promotes allergic airway inflammation

BACKGROUND

IL-33, levels of which are known to be increased in patients with eosinophilic asthma and which is suggested as a therapeutic target for it, activates endothelial cells in which Sry-related high-mobility-group box (Sox) 17, an endothelium-specific transcription factor, was upregulated.

OBJECTIVE

We investigated the relationship between Sox17 and IL-33 and the possible role of Sox17 in the pathogenesis of asthma using a mouse model of airway inflammation.

METHODS

We used ovalbumin (OVA) to induce airway inflammation in endothelium-specific Sox17 null mutant mice and used IL-33 neutralizing antibody to evaluate the interplay between IL-33 and Sox17. We evaluated airway inflammation and measured levels of various cytokines, chemokines, and adhesion molecules. We also carried out loss- or gain-of-function experiments for Sox17 in human endothelial cells.

RESULTS

Levels of IL-33 and Sox17 were significantly increased in the lungs of OVA-challenged mice. Anti-IL-33 neutralizing antibody treatment attenuated not only OVA-induced airway inflammation but also Sox17 expression in pulmonary endothelial cells. Importantly, endothelium-specific deletion of Sox17 resulted in significant alleviation of various clinical features of asthma, including airway inflammation, immune cell infiltration, cytokine/chemokine production, and airway hyperresponsiveness. Sox17 deletion also resulted in decreased densities of Ly6c^high monocytes and inflammatory dendritic cells in the lungs. In IL-33-stimulated human endothelial cells, Sox17 showed positive correlation with CCL2 and intercellular adhesion molecule 1 levels. Lastly, Sox17 promoted monocyte adhesion to endothelial cells and upregulated the extracellular signal-regulated kinase-signal transducer and activator of transcription 3 pathway.

CONCLUSION

Sox17 was regulated by IL-33, and its genetic ablation in endothelial cells resulted in alleviation of asthma-related pathophysiologic features. Sox17 might be a potential target for asthma management.

Association between thromboxane A2 receptor polymorphisms and asthma risk: A meta-analysis

OBJECTIVE

To determine whether there is an association between thromboxane A2 receptor (TBXA2R) gene polymorphisms (+924C/T and +795C/T) and asthma risk by conducting a meta-analysis.

DATA SOURCES

Pubmed, Embase, Chinese National Knowledge Infrastructure (CNKI) and Wanfang database were searched (updated May 1, 2015).

STUDY SELECTIONS

Articles evaluating the association between TBXA2R gene polymorphisms and asthma risk were selected.

RESULTS

A total of 7 studies on +924C/T polymorphism and 6 studies on +795C/T polymorphism were included in this meta-analysis. There was a significant association between TBXA2R +924C/T polymorphism and asthma risk in the recessive model (OR = 1.33, 95% CI = 1.01-1.75, P = 0.045). No significant association between +795C/T polymorphism and asthma risk in the overall population was demonstrated. In subgroup analyzes, significant association was observed in atopic asthma risk in the recessive model (OR = 1.43, 95% CI = 1.01-2.01, P = 0.043), but no significant association was found between TBXA2R +924C/T polymorphism and asthma risk in Asians (OR = 1.14, 95% CI = 0.80-1.63, P = 0.457). TBXA2R +795C/T polymorphism was associated with aspirin-intolerant asthma (AIA) risk when stratified by asthma subphenotype in the allelic model (OR = 1.30, 95% CI = 1.05-1.60, P = 0.014) and dominant model (OR = 1.50, 95% CI = 1.11-2.03, P = 0.008).

CONCLUSION

Our results suggested that TBXA2R +924C/T polymorphism is associated with asthma risk, and +795C/T polymorphism may be a risk factor for AIA. Larger-scale and well-designed studies are required to validate the association identified in the current meta-analysis.

Regulatory SNPs and transcriptional factor binding sites in ADRBK1, AKT3, ATF3, DIO2, TBXA2R and VEGFA

Abstract Regulatory single nucleotide polymorphisms (rSNPs) which change the transcriptional factor binding sites (TFBS) for transcriptional factors (TFs) to bind DNA were reviewed for the ADRBK1 (GRK2), AKT3, ATF3, DIO2, TBXA2R and VEGFA genes. Changes in the TFBS where TFs attach to regulate these genes may result in human sickness and disease. The highlights of this previous work were reviewed for these genes.