Asthma Susceptibility Research Articles

GSDMB Gene Polymorphisms and Their Association with Asthma Susceptibility: A Systematic Review and Meta-Analysis of Case–Control Studies

Background: Asthma is a respiratory disorder influenced by genetic and environmental factors. The rs7216389 polymorphism in the gasdermin B (GSDMB) gene on chromosome 17q21 has been implicated in asthma susceptibility with conflicting results. This meta-analysis aims to bring forward new findings on the association between this polymorphism and asthma across diverse populations and its potential as a genetic marker for asthma risk. Methods: A systematic review and meta-analysis were conducted through March 2024, and odd ratios were calculated. Results: The meta-analysis included 22 studies with a total of 9012 asthma patients and 11,657 controls. The results show an OR = 1.24, 95% CI [1.13, 1.37], p < 0.00001. Subgroup analyses stratified by age and ethnicity between asthma patients with T alleles vs. C alleles demonstrated an association between having the T allele and asthma susceptibility across Asian, Caucasian, and American minorities, but not among Arabs. Young asthma patients with the dominant allele (T) showed higher asthma risk than those with C allele or heterozygote TC, and to a higher extent than for adults. Conclusions: This meta-analysis indicates the importance of genetic factors in asthma in certain ethnicities and underscores the potential utility of the rs7216389 polymorphism as a genetic marker for asthma risk assessment.

Allele-specific micro-RNA-mediated regulation of ADAM33 in childhood allergic asthma.

A disintegrin and metalloprotease 33 (ADAM33) is associated with asthma susceptibility, and its genetic variations impact susceptibility and disease severity. However, the mechanisms remain unclear. This study aimed to investigate ADAM33 single nucleotide polymorphisms (SNPs) in childhood asthma susceptibility and explore their regulatory mechanisms. Eleven selected SNPs in ADAM33 were genotyped and identified the association with asthma susceptibility. In the validation cohort, we measured plasma sADAM33 levels and compared them with disease severity among children with different SNP genotypes. Computational predictions identified miRNAs targeting the SNP, and the impact of the SNP on miRNA regulation was confirmed using a dual luciferase reporter system. Finally, we validated the regulatory role of miRNAs on ADAM33 expression using an in vitro model with upregulated ADAM33 expression. Only rs3918400 was associated with asthma susceptibility. In the validation cohort, children with allergic asthma exhibited higher plasma sADAM33 levels. Among asthmatic children, those with the rs3918400 CT/TT genotype had higher sADAM33 levels, poorer asthma control, more severe airway hyper-responsiveness, lower FEV1% and higher dust mite-specific IgE activity compared to those with the CC genotype. miR-3928-5p bound strongly to the rs3918400 C allele and effectively reduced ADAM33 protein expression in CC genotype cells. However, the binding affinity of miR-3928-5p to the T allele was weaker, resulting in diminished negative regulation of protein expression. The rs3918400 SNP affects the negative regulation of ADAM33 by miR-3928-5p, potentially participating in a complex interplay of processes related to childhood asthma susceptibility.

Polymorphism Of Orosomucoid-Like 3 ORMDL3 Rs4795405 C>T In Iraqi Patients with Asthma

The aim of this study was to investigate the association of polymorphism of Orosomucoid-like 3 ORMDL3 rs4795405 C/T gene to the susceptibility of asthma among Iraqi asthmatic patients. Forty-five asthmatic patients (23 males and 22 females), their age 19-70 years and 35 healthy controls( 18 males and 17 females) ,their age 18-71years were selected from Wasit Province using a convenient sampling method. Genetic polymorphism of Orosomucoid-like 3 ORMDL3 rs4795405 C>T was carried out using TaqMan -PCR. both patients and control groups, the distribution frequencies of genotypes and alleles of the rs4795405 C/T gene were in Hardy-Weinberg equilibrium (P<0.05) .The most common genotype in both control and asthma patients was the heterozygous genotype CT with a percentage of 67% and 66% respectively. The genotype CC was higher in the asthmatic group (20%) compared to the control group (14%). In contrast, genotype TT, the less predominant genotype, was less in the asthmatic group were less in asthmatic group (13%) compared control group (20%).The C allele was more frequent in asthma patients than in healthy controls (53.33%vs47.14%), whereas the T allele was frequent in healthy controls than in asthma patients (52.86% vs 46.67%) with no significant differences. The association analysis displayed that the individuals carrying the homozygous CC genotype were more likely to have a increased risk of asthma with OR=1.5(CI95% 0.4537to4.9593) ,P=0.5063.The heterozygous genotypes CT was not associated with asthma with OR=1.0 (CI95%0.4103 to2.6538 ),P=0.9288 . The TT genotype decreases the association with asthma OR=0.6 (CI950.1865 to2.0302), P =0.4253. These results suggested that the T allele might play a protective role against asthma whereas the C allele might consider a risk factor in asthma. The subgroup analysis revealed that the asthma risk of females with ORMDL3 CC genotype was 2.4 fold increases the risk of asthma OR=2.4889 (CI95% 0.5478to11.3081), P= 0.2377 The TC and TT genotype decreases the association with the disease with with OR = 0.8485 (CI 95% 0.2312to3.1142), P = 0.8044 and OR= 0.2121(CI95% 0.02 to2.2473)P =0.1979 respectively. Among males, ORMDL3 CT genotype ncreased asthmatic risk among patients’ males 1.3 fold, OR= 1.3333 (CI95%0.3433 to 5.1781), P=0.6777. The genotype CC decreases the association with the disease OR=0.3810 (CI95%0.0317to 4.5813), P=0.4469. While, the homozygous TT genotype was not associated with the disease OR=1.0294 (CI95% 0,2313 to4.5814), P=0.9696. The analysis of genetic model for Orosomucoid-lik 3 ORMDL3 rs4795405 showed the recessive model (CC+CT/ TT ) increased the association with the asthma OR=1.6250 P=0.4253.The Over-dominant model(CT+TT/ CC) and the dominant model(CT+TT/ CC) decreased the association with asthma OR=0.9583,P=0.9288and OR= 0.6667 ,P=0.5063 respectively.

Epigenetics and Asthma: A Systematic Review.

Asthma is a chronic respiratory condition characterized by the narrowing of the airways, causing difficulty in breathing. Its heritability has long been an area of research, and the study of genetics alone has not been sufficient in the explanation of both its heritability and susceptibility. The study of epigenetics, which is defined as "the study of heritable changes in gene expression that do not involve changes to the underlying DNA sequence," can be used to explain the heritability and susceptibility of asthma. These epigenetic alterations to our DNA are influenced by environmental factors which are already known as risk factors for asthma; these include factors such as diet, smoking, and air pollution. The epigenetic mechanisms work by altering gene transcription and therefore determine whether specific genes are expressed, such mechanisms include DNA methylation and histone acetylation.

Secretory IgA in breast milk protects against asthma through modulation of the gut microbiota

Asthma susceptibility is linked to dysbiosis in early-life gut microbiota, and the antibody secretory immunoglobulin (Ig)A (SIgA) is a key determinant of gut microbiota composition. SIgA is obtained through breast milk during the critical early-life window. We use a mouse model of SIgA deficiency and the house dust mite (HDM) model of asthma to elucidate the role of maternal SIgA in modulating the early-life gut microbiota and asthma protection. Mice that do not receive maternal SIgA display a transient bloom of segmented filamentous bacteria (SFB) in the small intestine during the early post-weaning period. Mice that do not receive maternal SIgA also display elevated T helper type 17 (Th17) cell activation in the intestine, which persists into adulthood and is associated with more severe inflammation in response to the HDM model of asthma. This study demonstrates a mechanism by which breast-milk-derived SIgA influences immune development and asthma susceptibility by modulating the early-life gut microbiota.

Causal relationship between Lipdome and Chronic Obstructive Pulmonary Disease and Asthma: Mendelian randomization

Genetic risk significantly influence susceptibility and heterogeneity of chronic obstructive pulmonary disease (COPD) and asthma, and increasing evidence suggests their close association with lipdome. However, their causal relationship remains unclear. In this study, we conducted a two-sample MR (Mendelian randomization) analysis using publicly available large-scale genome-wide association studies (GWAS) data to evaluate the causal impact of lipdome on COPD and asthma. The inverse variance weighted (IVW) method served as the primary analysis method, and multiple sensitivity and heterogeneity tests were performed to assess the reliability of the results. Finally, a Meta-analysis was conducted on lipdome with significant causal relationships to validate the robustness of the results. Our findings suggest that Sterol ester (27:1/18:2), Phosphatidylcholine (15:0_18:2), (16:0_18:2), (16:0_20:2), (17:0_18:2), (18:1_18:1), (18:1_18:2), (18:1_20:2), Triacylglycerol (54:3), and (56:4) levels are protective factors for COPD, while levels of Phosphatidylcholine (16:0_22:5), (18:0_20:4), and (O-16:0_20:4) are risk factors for COPD. Meta-analysis of lipids causally related to COPD also indicates significant results. Phosphatidylcholine (16:0_20:4), (16:0_22:5), and (18:0_20:4) levels are risk factors for asthma, while Phosphatidylcholine (18:1_18:2), (18:1_20:2), and Sphingomyelin (d38:1) levels are protective factors for asthma. However, the lack of statistical significance in the Meta-analysis may be due to heterogeneity in research methods and data statistics. This study indicates that 4 lipdome species have significant correlations with COPD and asthma. Phosphatidylcholine (18:1_18:2) and (18:1_20:2) are protective factors, while Phosphatidylcholine (16:0_22:5) and (18:0_20:4) are risk factors. Additionally, due to differences in molecular subtypes, phosphatidylcholine, sterol ester, and triacylglycerol exhibit differential effects on the diseases.

Causal associations among gut microbiota, 1400 plasma metabolites, and asthma: a two-sample Mendelian randomization study.

Emerging evidence indicates a correlation between imbalances in intestinal microbiota and changes in plasma metabolites in the progression of asthma. However, the causal link between these factors remains unclear. A two-sample Mendelian randomization (MR) study was employed to evaluate the potential causal connection between gut microbiota, plasma metabolites, and asthma susceptibility. Gut microbiota data from expansive genome-wide genotype studies and 16S fecal microbiome datasets were examined by the MiBioGen Alliance. Asthma data were procured from the FinnGen biobank analysis, while comprehensive Genome-Wide Association Studies (GWAS) summary statistics for plasma metabolites were derived from the NHGRI-EBI GWAS Catalog. Fluctuations in intestinal flora and plasma metabolites in asthma patients were evaluated using the weighted mode method. Additionally, pleiotropic and heterogeneity analyses were performed to ascertain the reliability of the findings. Upon examining the gut microbiota through MR with the IVW method, alongside tests for heterogeneity and pleiotropy, findings reveal a negative association between the abundance of the Christensenellaceae R.7 group and asthma risk. In contrast, the Bifidobacterium and Prevotella 7 genera exhibit a positive association with asthma risk, indicating they may be potential risk factors (p < 0.05). Furthermore, MR analysis of 1,400 metabolites employing Weighted median, IVW, and Weighted mode methods resulted in p-values below 0.05. Subsequent tests for pleiotropy and heterogeneity showed that the levels of 3,5-dichloro-2,6-dihydroxybenzoic acid have a negative correlation with asthma, whereas the phenylalanine to phosphate ratio has a positive correlation, suggesting their potential as risk factors for asthma (p < 0.05). The current Mendelian randomization study provides evidence supporting a potential causal link between specific gut microbiota taxa, plasma metabolites, and asthma. These findings offer novel perspectives for future research and the development of treatment and prevention strategies for asthma.

Impact of Interleukin-17 Receptor A Gene Variants on Asthma Susceptibility and Clinical Manifestations in Children and Adolescents.

Several single nucleotide polymorphisms (SNPs) in multiple interleukin receptor genes could be associated with asthma risk and/or phenotype. Interleukin-17 (IL-17) has been implicated in tissue inflammation and autoimmune diseases. As no previous studies have uncovered the potential role of IL17 receptor A (RA) gene variants in asthma risk, we aimed to explore the association of four IL17RA SNPs (i.e., rs4819554A/G, rs879577C/T, rs41323645G/A, and rs4819555C/T) with asthma susceptibility/phenotype in our region. TaqMan allelic discrimination analysis was used to genotype 192 individuals. We found that the rs4819554 G/G genotype significantly reduced disease risk in the codominant (OR = 0.15, 95%CI = 0.05-0.45, p < 0.001), dominant (OR = 0.49, 95%CI = 0.26-0.93, p = 0.028), and recessive (OR = 0.18, 95%CI = 0.07-0.52, p < 0.001) models. Similarly, rs879577 showed reduced disease risk associated with the T allele across all genetic models. However, the A allele of rs41323645 was associated with increased disease risk in all models. The G/A and A/A genotypes have higher ORs of 2.47 (95%CI = 1.19-5.14) and 3.86 (95%CI = 1.62-9.18), respectively. Similar trends are observed in the dominant 2.89 (95%CI = 1.47-5.68, p = 0.002) and recessive 2.34 (95%CI = 1.10-4.98, p = 0.025) models. For the rs4819555 variant, although there was no significant association identified under any models, carriers of the rs4819554*A demonstrated an association with a positive family history of asthma (71.4% in carriers vs. 27% in non-carriers; p = 0.025) and the use of relievers for >2 weeks (52.2% of carriers vs. 28.8% of non-carriers; p = 0.047). Meanwhile, the rs4819555*C carriers displayed a significant divergence in the asthma phenotype, specifically atopic asthma (83.3% vs. 61.1%; p = 0.007), showed a higher prevalence of chest tightness (88.9% vs. 61.5%; p = 0.029), and were more likely to report comorbidities (57.7% vs. 16.7%, p = 0.003). The most frequent haplotype in the asthma group was ACAC, with a frequency of 22.87% vs. 1.36% in the controls (p < 0.001). In conclusion, the studied IL17RA variants could be essential in asthma susceptibility and phenotype in children and adolescents.

Investigation of lactotransferrin messenger RNA expression levels as an anti–type 2 asthma biomarker

Lactotransferrin (LTF) has an immunomodulatory function, and its expression levels are associated with asthma susceptibility. We sought to investigate LTF messenger RNA (mRNA) expression levels in human bronchial epithelial cells (BECs) as an anti-type 2 (T2) asthma biomarker. Association analyses between LTF mRNA expression levels in BECs and asthma-related phenotypes were performed in the Severe Asthma Research Program (SARP) cross-sectional (n= 155) and longitudinal (n= 156) cohorts using a generalized linear model. Correlation analyses of mRNA expression levels between LTF and all other genes were performed by Spearman correlation. Low LTF mRNA expression levels were associated with asthma susceptibility and severity (P< .025), retrospective andprospective asthma exacerbations, and low lung function (P< 8.3×10-3). Low LTF mRNA expression levels were associated with high airway T2 inflammation biomarkers (sputum eosinophils and fractional exhaled nitric oxide; P<8.3×10-3) but were not associated with blood eosinophils or total serum IgE. LTF mRNA expression levels were negatively correlated with expression levels of TH2 or asthma-associated genes (POSTN, NOS2, and MUC5AC) and eosinophil-related genes (IL1RL1, CCL26, and IKZF2) and positively correlated with expression levels of TH1 and inflammation genes (IL12A, MUC5B, and CC16) and TH17-driven cytokines or chemokines for neutrophils (CXCL1,CXCL6, and CSF3) (P< 3.5×10-6). Low LTF mRNA expression levels in BECs are associated with asthma susceptibility, severity, and exacerbations through upregulation of airway T2 inflammation. LTF is a potential anti-T2 biomarker, and its expression levels may help determine the balance of eosinophilic and neutrophilic asthma.

High humidity and NO2 co-exposure exacerbates allergic asthma by increasing oxidative stress, inflammatory and TRP protein expressions in lung tissue

Allergic asthma is a chronic inflammatory airway disease with a high mortality rate and a rapidly increasing prevalence in recent decades that is closely linked to environmental change. Previous research found that high humidity (HH) and the traffic-related air pollutant NO2 both aggregated allergic asthma. Their combined effect and mechanisms on asthma exacerbation, however, are unknown. Our study aims to toxicologically clarify the role of HH (90%) and NO2 (5 ppm) on allergic asthma. Ninety male Balb/c mice were randomly assigned to one of six groups (n = 15 in each): saline control, ovalbumin (OVA)-sensitized, OVA + HH, OVA + NO2, OVA + HH + NO2, and OVA + HH + NO2+Capsazepine (CZP). After 38 days of treatment, the airway function, pathological changes in lung tissue, blood inflammatory cells, and oxidative stress and inflammatory biomarkers were comprehensively assessed. Co-exposure to HH and NO2 exacerbated histopathological changes and airway hyperresponsiveness, increased IgE, oxidative stress markers malonaldehyde (MDA) and allergic asthma-related inflammation markers (IL-1β, TNF-α and IL-17), and upregulated the expressions of the transient receptor potential (TRP) ion channels (TRPA1, TRPV1 and TRPV4). Our findings show that co-exposure to HH and NO2 disrupted the Th1/Th2 immune balance, promoting allergic airway inflammation and asthma susceptibility, and increasing TRPV1 expression, whereas CZP reduced TRPV1 expression and alleviated allergic asthma symptoms. Thus, therapeutic treatments that target the TRPV1 ion channel have the potential to effectively manage allergic asthma.

Genetic association of inflammatory marker GlycA with lung function and respiratory diseases

Association of circulating glycoprotein acetyls (GlycA), a systemic inflammation biomarker, with lung function and respiratory diseases remain to be investigated. We examined the genetic correlation, shared genetics, and potential causality of GlycA (N = 115,078) with lung function and respiratory diseases (N = 497,000). GlycA showed significant genetic correlation with FEV1 (rg = −0.14), FVC (rg = −0.18), asthma (rg = 0.21) and COPD (rg = 0.31). We consistently identified ten shared loci (including chr3p21.31 and chr8p23.1) at both SNP and gene level revealing potential shared biological mechanisms involving ubiquitination, immune response, Wnt/β-catenin signaling, cell growth and differentiation in tissues or cells including blood, epithelium, fibroblast, fetal thymus, and fetal intestine. Genetically elevated GlycA was significantly correlated with lung function and asthma susceptibility (354.13 ml decrement of FEV1, 442.28 ml decrement of FVC, and 144% increased risk of asthma per SD increment of GlycA) from MR analyses. Our findings provide insights into biological mechanisms of GlycA in relating to lung function, asthma, and COPD.

Association of TLR4 gene rs4986790 and rs4986791 polymorphisms with asthma susceptibility: meta-analysis and trial sequential analysis.

The current understanding of the correlation between TLR4 gene (toll-like receptor 4) rs4986790 and rs4986791 polymorphisms and asthma susceptibility is inconclusive, with studies and populations yielding conflicting results. Evaluate this relationship using meta-analysis and trial sequential analysis (TSA). Databases were systematically queried for relevant articles from the establishment of the database to 19 June 2023 adhering to predefined inclusion and exclusion criteria. Two authors independently conducted screening, data extraction, and quality evaluation. Meta-analysis and TSA were carried out using RevMan 5.4, StataMP 17.0, and TSA 0.9.5.10 Beta, with α=0.05. Subgroup analyses were conducted based on racial demographics. A sensitivity analysis was conducted employing a one-by-one exclusion method. Publication bias was assessed using the Begg and Egger tests. Association of asthma susceptibility with TLR4 gene rs4986790 and rs4986791 polymorphisms. 23 articles included 22 studies on the rs4986790 polymorphism and 11 studies on the rs4986791 polymorphism on the TLR4 gene. Out of 692 studies screened, 23 met the inclusion criteria. While the overall meta-analysis showed no significant association between the TLR4 rs4986790 polymorphism and asthma susceptibility, subgroup analysis revealed a significant link in the Caucasian population. A significant association was noted in the meta-analysis, particularly among Asian populations, on the rs4986791 polymorphism. The sensitivity analysis indicated that the meta-analysis results were relatively stable. Publication bias analysis revealed minimal influence from publication bias. However, TSA was underscored by the necessity for additional original studies to further validate specific outcomes. Our study underscores the ethnicity-specific impact on the relationship between TLR4 polymorphisms and asthma susceptibility. While the overall findings for rs4986790 were not significant, the association with the Caucasian population merits further investigation. Furthermore, rs4986791 demonstrated a significant correlation with asthma susceptibility, specifically among Asian populations. Our study predominantly examined the rs4986790 and rs4986791 polymorphisms, overlooking the potential influence of other genetic variants within TLR4.

ADAM33's Role in Asthma Pathogenesis: An Overview.

Asthma is a complex chronic respiratory disease characterized by airway hyperresponsiveness, inflammation, and obstruction. Many genes have been identified as associated with asthma but none with such substantial significance as the ADAM33 gene due to its role in airway remodeling and bronchial hyperresponsiveness. This review summarizes the current knowledge on the genetic and functional aspects of ADAM33 in asthma pathogenesis. We highlight its genetic variants associated with asthma susceptibility and severity, as well as the functional effects of ADAM33 on airway remodeling, smooth muscle cell proliferation, and its interplay with environmental factors. Additionally, we discuss the potential clinical implications of ADAM33 as a therapeutic target for asthma management.

Genetic Diversity in Bronchial Asthma Susceptibility: Exploring the Role of Vitamin D Receptor Gene Polymorphisms in Varied Geographic Contexts.

Bronchial asthma (BA) exhibits varying prevalence across global populations, prompting a comprehensive investigation into genetic and environmental determinants. Vitamin D is a potent immunomodulator capable of suppressing inflammatory signals in several cell types involved in the asthmatic response; it exerts effects on the immune system by binding to the nuclear vitamin D receptor (VDR). VDR gene genetic variations are affecting serum vitamin D levels with a possible role in the BA risk. The current study aimed to examine the complex interaction of various factors (genetic background, serum vitamin D levels, and geographic location) to identify differences in the influence of these factors on the susceptibility to asthma between populations at different latitudes. Focusing on Eastern European cohorts from Latvia and Lithuania and comparing them with published data on East Asian populations, we explore the impact of VDR gene polymorphisms on BA susceptibility. Genotyping four key VDR SNPs and assessing their association with 25-hydroxyvitamin D levels, our study unveils significant associations of the studied loci with the risk of asthma-both risk-reducing and increasing effects, differently distributed between Baltic and East Asian populations. The functional effects of in silico VDR gene genetic variations are also identified and discussed.

The gut-lung axis and asthma susceptibility in early life.

Asthma is the most common chronic disease among children, with more than 300 million cases worldwide. Over the past several decades, asthma incidence has grown, and epidemiological studies identify the modernized lifestyle as playing a strong contributing role in this phenomenon. In particular, lifestyle factors that modify the maternal gut microbiome during pregnancy, or the infant microbiome in early life, can act as developmental programming events which determine health or disease susceptibility later in life. Microbial colonization of the gut begins at birth, and factors such as delivery mode, breastfeeding, diet, antibiotic use, and exposure to environmental bacteria influence the development of the infant microbiome. Colonization of the gut microbiome is crucial for proper immune system development and disruptions to this process can predispose a child to asthma development. Here, we describe the importance of early-life events for shaping immune responses along the gut-lung axis and why they may provide a window of opportunity for asthma prevention.

Impacts of Matrix Metalloproteinase-9 Promoter Genotypes on Asthma Risk.

The overexpression of matrix metalloproteinase-9 (MMP9) has been observed in asthmatic patients, yet the role of MMP9 genotype in determining asthma susceptibility remains unresolved. This study aimed to elucidate the contribution of MMP9 promoter rs3918242 genotype to asthma risk in Taiwan. A cohort comprising 453 non-asthmatic healthy controls and 198 asthmatic cases was assembled, and the MMP9 rs3918242 genotypes were determined using polymerase chain reaction-restriction fragment length polymorphism methodology. Our findings indicated that people carrying the variant CT or TT genotype of MMP9 rs3918242 did not demonstrate an elevated risk of asthma compared to wild-type CC carriers (odds ratio=1.28 and 1.72, 95% confidence interval=0.87-1.87 and 0.72-4.13; p=0.2417 and 0.3201, respectively). Furthermore, individuals carrying the T allele at MMP9 rs3918242 did not exhibit a higher risk of asthma than those carrying the C allele (odds ratio=1.31, 95% confidence interval=0.96-1.79, p=0.0869). Interestingly, a positive association was observed between MMP9 rs3918242 CT or TT genotypes and the severity of asthma symptoms among asthmatic patients (p=0.0035). Although the T allele at MMP9 rs3918242 was not associated with asthma risk, it may serve as a predictor for asthma symptom severity. These findings warrant validation in larger and more diverse populations to further elucidate the significance of MMP9 in asthma etiology.

Association of GAB1 gene with asthma susceptibility and the efficacy of inhaled corticosteroids in children

Asthma is a polygenic disease that may onset during childhood. Inhaled corticosteroids (ICS) are the main therapy in asthma, although their efficacy varies among individuals. Nuclear factor κB (NF-κB) is an important target of ICS treatment of asthma. Recent research has reported that GRB2 associated binding protein 1 (GAB1) gene may participate in the pathogenesis of asthma by regulating the NF-κB pathway. Therefore, we used the technique of an improved multiplex ligation detection reaction to sequence GAB1 gene and investigated the involvement of Single-nucleotide variants (SNVs) in GAB1 gene in asthma and ICS efficacy in asthmatic children. We found no differences between asthma cases and controls in allele or genotype frequencies of GAB1. Haplotype analysis showed an increased tendency for AGGAGC frequency in asthma patients compared with controls (OR = 2.69, p = 0.018). The percentage of EOS and genotype distribution of rs1397527 were associated (p = 0.007). The EOS percentage was higher in GT genotype when compared to the GG genotype (5.50 vs 3.00, Bonferroni adjusted p = 0.005). After 12-weeks ICS treatment, GAB1 rs1397527 TT and GT genotype carriers had a smaller change in forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) than GG carriers (p = 0.009), and rs3805236 GG and AG genotype carriers also had a smaller change in FEV1/FVC than AA carriers (p = 0.025). For ICS response, the frequency of GG genotype of rs1397527 was significantly higher in good responders (p = 0.038). The generalized multifactor dimensionality reduction (GMDR) analysis showed a best significant four-order model (rs1397527, allergen exposure, environmental tobacco smoke exposure, and pet exposure) involving gene-environment interactions (p = 0.001). In summary, we found that GAB1 SNVs were not associated with asthma susceptibility. Haplotype AGGAGC was a risk factor for asthma. GAB1 variants were associated with eosinophils and ICS response in asthmatics. Furthermore, gene-environment interaction was observed.

IL-23 contributes to Particulate Matter induced allergic asthma in the early life of mice and promotes asthma susceptibility.

Air pollutant exposure leads to and exacerbates respiratory diseases. Particulate Matter (PM) is a major deleterious factor in the pathophysiology of asthma. Nonetheless, studies on the effects and mechanisms of exposure in the early life of mice remain unresolved. This study aimed to investigate changes in allergic phenotypes and effects on allergen-specific memory T cells resulting from co-exposure of mice in the early life to PM and house dust mites (HDM) and to explore the role of interleukin-23 (IL-23) in this process. PM and low-dose HDM were administered intranasally in 4-day-old C57BL/6 mice. After confirming an increase in IL-23 expression in mouse lung tissues, changes in the asthma phenotype and lung effector/memory Th2 or Th17 cells were evaluated after intranasal administration of anti-IL-23 antibody (Ab) during co-exposure to PM and HDM. Evaluation was performed up to 7weeks after the last administration. Co-exposure to PM and low-dose HDM resulted in increases in airway hyperresponsiveness (AHR), eosinophils, neutrophils, and persistent Th2/Th17 effector/memory cells, which were all inhibited by anti-IL-23 Ab administration. When low-dose HDM was administered twice after a 7-week rest, mice exposed to PM and HDM during the previous early life period exhibited re-increases AHR, eosinophil count, HDM-specific IgG1, and effector/memory Th2 and Th17 cell populations. However, anti-IL-23 Ab administration during the early life period resulted in inhibition. Co-exposure to PM and low-dose HDM reinforced the allergic phenotypes and allergen-specific memory responses in early life of mice. During this process, IL-23 contributes to the enhancement of effector/memory Th2/Th17 cells and allergic phenotypes. KEY MESSAGES: PM-induced IL-23 expression, allergic responses in HDMinstilled mice of early life period. PM-induced effector/memory Th2/Th17 cells in HDMinstilled mice of early life period. Inhibition of IL-23 reduced the increase in allergic responses. Inhibition of IL-23 reduced the increase in allergic responses. After the resting period, HDM administration showed re-increase in allergic responses. Inhibition of IL-23 reduced the HDM-recall allergic responses.

The effect of genetic variation and mRNA expression of interleukin-17A gene on susceptibility to asthma.

Analyzing the genetic variation and mRNA expression of interleukin-17A (IL-17A) gene and its impact on asthma susceptibility was the purpose of this study. 120 asthma patients were selected as the asthma group, and another 120 healthy individuals who underwent physical examination were selected as the health group; Compare the cytokine levels and mRNA expression of IL-17A between two groups, as well as the clinical indicator total immunoglobulin E (TIgE) levels; The genotype and allele distribution frequency of IL-17A Single-nucleotide polymorphism locus rs2275913 and rs8193036 were compared between the two groups; Compare the serum IL-17A and TIgE levels of different genotypes at rs2275913 and rs8193036 loci; and logistic regression was used to evaluate the impact of IL-17A on asthma susceptibility. The serum levels of IL-17A, TIgE, and IL-17AmRNA expression in the asthma group were higher than those in the healthy group (P<0.05). There were three genotypes of AA, AG and GG at rs2275913 locus, and the frequency distribution between the two groups was significant (P<0.05), and the frequency of A Allele frequency in asthma group was higher than that in healthy group (P<0.05). There are three genotypes of CC, CT, and TT at the rs8193036 locus, and there was no significant difference in the frequency distribution between the two groups (P>0.05). There is no difference in the frequency distribution of alleles C and T between the two groups (P>0.05). The levels of IL-17A and TIgE in the rs2275913AA genotype were higher than those in the AG and GG genotypes (P<0.05); There was no difference in IL-17A and TIgE levels among different genotypes of rs8193036 (P>0.05). The rs2275913 polymorphism was associated with asthma susceptibility and is an independent risk parameter for asthma susceptibility. Upregulation of serum IL-17A and TIgE, as well as overexpression of IL-17A mRNA, were closely related to asthma susceptibility in asthma patients. The rs2275913 polymorphism had a significant role in increasing the risk of asthma, and variant allele A may be a susceptibility factor for increasing asthma risk.

A missing jigsaw within the hygiene hypothesis: Low-dose bisphenol A exposure attenuates lipopolysaccharide-induced asthma protection.

The rising occurrence of allergic asthma in early life across industrialized countries suggests that environmental factors play a crucial role in determining asthma susceptibility and severity. While prior exposure to microbial lipopolysaccharides (LPSs) has been found to offer protection against allergic asthma, infants residing in urban environments are increasingly exposed to environmental pollutants. Utilizing limulus lysate test screens and virtual screening models, we identified pollutants that can modulate LPS bioactivity. This investigation revealed that bisphenol A (BPA), a chemical commonly used in numerous household items and previously implicated in obesity and cancer, effectively neutralizes LPS. In-depth mechanistic analyses showed that BPA specifically binds to the lipid A component of LPS, leading to inactivation. This interaction eliminates the immunostimulatory activity of LPS, making mice more susceptible to house dust mite (HDM)-induced allergic asthma. BPA reactivates lung epithelial cells, consequently amplifying type 2 responses to HDMs in dendritic cells. This chemical interplay provides new insights into the pathophysiology of asthma in relation to human exposure. Understanding the intricate relationships between environmental chemicals and microbial antigens, as well as their impacts on innate immunity, is critical for the development of intervention strategies to address immune disorders resulting from urbanization.