Molecular interaction network and pathway studies of ADAM33 potentially relevant to asthma

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.

Role of ADAM and ADAMTS proteases in pathological tissue remodeling

Pathological tissue remodeling is closely associated with the occurrence and aggravation of various diseases. A Disintegrin And Metalloproteinases (ADAM), as well as A Disintegrin And Metalloproteinase with ThromboSpondin motifs (ADAMTS), belong to zinc-dependent metalloproteinase superfamily, are involved in a range of pathological states, including cancer metastasis, inflammatory disorders, respiratory diseases and cardiovascular diseases. Mounting studies suggest that ADAM and ADAMTS proteases contribute to the development of tissue remodeling in various diseases, mainly through the regulation of cell proliferation, apoptosis, migration and extracellular matrix remodeling. This review focuses on the roles of ADAM and ADAMTS proteinases in diseases with pathological tissue remodeling, with particular emphasis on the molecular mechanisms through which ADAM and ADAMTS proteins mediate tissue remodeling. Some of these reported proteinases have defined protective or contributing roles in indicated diseases, while their underlying regulation is obscure. Future studies are warranted to better understand the catalytic and non-catalytic functions of ADAM and ADAMTS proteins, as well as to evaluate the efficacy of targeting these proteases in pathological tissue remodeling.

Association between ADAM33 Single-Nucleotide Polymorphisms and Treatment Response to Inhaled Corticosteroids and a Long-Acting Beta-Agonist in Asthma

ADAM33 has been linked to airway structural changes in patients with asthma, leading to airway hyperresponsiveness, narrowing, and ultimately poor treatment responsiveness. This study aimed to evaluate the genetic association of ADAM33 SNPs with asthma, disease severity, and treatment responsiveness to ICS+LABA in the South Indian population. In this case-control study (486 controls and 503 cases), we performed genotyping using MassArray for six SNPs of ADAM33, namely rs2280091, rs2787094, rs3918396, rs67044, rs2853209, and rs3918392. We studied the association with asthma and treatment responsiveness to ICS+LABA, using genotype, allele frequency distribution, and haplotype analysis. A significant clinical finding of the study was that certain patients in the disease severity group (moderate and mild) showed poor or no improvement after a three-month follow-up of regular ICS+LABA therapy. Of the studied ADAM33 SNPs, rs2853209 showed an association with asthma. The further analysis of asthma patients according to disease severity suggested an association between moderate disease and the minor allele "T" for rs2853209. The homozygous minor allele of SNP rs2787094 was found to be associated with poorer lung function and the least lung-function improvement after three months of ICS+LABA therapy. The haplotype analysis of six SNPs showed a significant association between the rs2853209 and rs3918396 blocks and asthma. ADAM33 gene polymorphism has clinical relevance in terms of disease association and response to treatment. SNP rs2853209 seemed most relevant to asthma, and SNP rs2787094 could be a genetic marker for predicting response to ICS+LABA therapy in the study population.

Role of microRNAs in type 2 diseases and allergen-specific immunotherapy

MicroRNAs (miRs) have gained scientific attention due to their importance in the pathophysiology of allergic diseases as well as their potential as biomarkers in allergen-specific treatment options. Their function as post-transcriptional regulators, controlling various cellular processes, is of high importance since any single miR can target multiple mRNAs, often within the same signalling pathway. MiRs can alter dysregulated expression of certain cellular responses and contribute to or cause, but in some cases prevent or repress, the development of various diseases. In this review article, we describe current research on the role of specific miRs in regulating immune responses in epithelial cells and specialized immune cells in response to various stimuli, in allergic diseases, and regulation in the therapeutic approach of allergen-specific immunotherapy (AIT). Despite the fact that AIT has been used successfully as a causative treatment option since more than a century, very little is known about the mechanisms of regulation and its connections with microRNAs. In order to fill this gap, this review aims to provide an overview of the current knowledge.

Integrin-α9β1 as a Novel Therapeutic Target for Refractory Diseases: Recent Progress and Insights

Integrins refer to heterodimers consisting of subunits α and β. They serve as receptors on cell membranes and interact with extracellular ligands to mediate intracellular molecular signals. One of the least-studied members of the integrin family is integrin-α9β1, which is widely distributed in various human tissues and organs. Integrin-α9β1 regulates the physiological state of cells through a variety of complex signaling pathways to participate in the specific pathological processes of some intractable diseases. In recent years, an increasing amount of research has focused on the role of α9β1 in the molecular mechanisms of different refractory diseases and its promising potential as a therapeutic target. Accordingly, this review introduces and summarizes recent research related to integrin-α9β1, describes the synergistic functions of α9β1 and its corresponding ligands in cancer, autoimmune diseases, nerve injury and thrombosis and, more importantly, highlights the potential of α9β1 as a distinctive target for the treatment of these intractable diseases.

Neurotrophic factors and their receptors in lung development and implications in lung diseases

Although lung innervation has been described by many studies in humans and rodents, the regulation of the respiratory system induced by neurotrophins is not fully understood. Here, we review current knowledge on the role of neurotrophins and the expression and function of their receptors in neurogenesis, vasculogenesis and during the embryonic development of the respiratory tree and highlight key implications relevant to respiratory diseases.

Haplotype analysis of ADAM33 polymorphisms in asthma: A pilot study

Background & objectives

ADAM33 is implicated as a potentially strong candidate gene for asthma and bronchial hyper-responsiveness. Many polymorphisms of ADAM33 have been studied along with ADAM33 expression in various cells of the lungs. Haplotype analysis also showed association with asthma in different populations across the world. Therefore, the aim of this study was to perform a comprehensive screening of ADAM33 polymorphisms in adult patients with asthma.

Methods

Thirty five polymorphisms of ADAM33 were genotyped in 55 patients with asthma and 53 controls. The association of single nucleotide polymorphisms (SNPs) and haplotypes with phenotypes of asthma was analysed.

Results

The genotype, minor allele frequency, odds ratio and Hardy-Weinberg equilibrium did not show any significant difference among cases and controls. No association was found between SNPs of ADAM33 with the severity of asthma. Correlation analysis of ADAM33 SNPs to the phenotypes, based on clinical variables and allergen sensitization, did not show significant difference. Haplotype analysis showed that rs2280090 and rs2280091 were associated with asthma in the patient group.

Interpretation & conclusions

Haplotype analysis showed an association of the two SNP variations with asthma. These SNPs lead to amino acid change and are prone to phosphorylation, which may affect expression levels and protein function of ADAM33 and asthma susceptibility.

YRNAs overexpression and potential implications in allergy

Background

Small non-coding RNAs (snRNAs) develop important functions related to epigenetic regulation. YRNAs are snRNAs involved in the initiation of DNA replication and RNA stability that regulate gene expression. They have been related to autoimmune, cancer and inflammatory diseases but never before to allergy. In this work we described for the first time in allergic patients the differential expression profile of YRNAs, their regulatory mechanisms and their potential as new diagnostic and therapeutic targets.

Methods

From a previous whole RNAseq study in B cells of allergic patients, differential expression profiles of coding and non-coding transcripts were obtained. To select the most differentially expressed non coding transcripts, fold change and p-values were analyzed. A validation of the expression differences detected was developed in an independent cohort of 304 individuals, 208 allergic patients and 96 controls by using qPCR. Potential binding and retrotransponibility capacity were characterized by in silico structural analysis. Using a novel bioinformatics approach, RNA targets identification, functional enrichment and network analyses were performed.

Results

We found that almost 70% of overexpressed non-coding transcripts in allergic patients corresponded to YRNAs. From the three more differentially overexpressed candidates, increased expression was independently confirmed in the peripheral blood of allergic patients. Structural analysis suggested a protein binding capacity decrease and an increase in retrotransponibility. Studies of RNA targets allowed the identification of sequences related to the immune mechanisms underlying allergy.

Conclusions

Overexpression of YRNAs is observed for the first time in allergic patients. Structural and functional information points to their implication on regulatory mechanisms of the disease.

Association between ADAM33 polymorphisms and asthma risk: a systematic review and meta-analysis

Background

Asthma is a common complex chronic, inflammatory polygenic disease with heterogeneous manifestations, affecting individuals of all age groups and posing an immense burden on healthcare resources. A number of studies have identified the association between a disintegrin and metalloprotease 33 (ADAM33) polymorphisms and asthma risk, however, the results still remain inconclusive. The objective of the present study was to identify the effect of ADAM33 variants in asthma susceptibility.

Methods

Eligible case-control studies published between January 2000 and June 2018 was searched and retrieved from online electronic databases. The odds ratio (OR) with its 95% confidence interval (CI) was employed to calculate the effect.

Results

A total of 63 case-control studies were finally screened out, including 13,280 asthma patients and 13,340 controls. Eleven SNPs of ADAM33 gene were identified. Our results detected a significant association between ADAM33 T2, Q1, F + 1 and AA genotype of T + 1 polymorphisms and asthma risk in total population. Subgroup analysis by ethnicities showed that the alleles and genotypes of T2, Q1 and F + 1 polymorphisms were associated with asthma susceptibility among Asian populations, while V4 polymorphism was associated with asthma among Caucasian populations. Subgroup analysis by ages showed that T2, F + 1 and ST + 4 polymorphisms were associated with childhood asthma, while Q1 and V4 polymorphisms were associated with asthma risk in adults. Subgroup analysis by asthma severity showed that only the G allele of ADAM33 T1 polymorphism was associated with the severity of asthma when compared with the controls. In addition, T2, Q1 and F + 1 polymorphisms of ADAM33 were significantly associated with increased the asthma risk in Chinese asthma patients.

Conclusions

Our results found that T2, Q1 and F + 1 polymorphisms of ADAM33 gene might contribute to asthma risk. Future well-designed case-control studies with large population and more ethnicities are still needed to estimate the association.

Identification of differentially expressed genes associated with asthma in children based on the bioanalysis of the regulatory network

Asthma, the most common chronic respiratory tract disease in children, is characterized by allergy, recurring airway obstruction and bronchospasm. The aim of the present study was to screen critical differentially expressed genes (DEGs) involved in asthma in children. Gene expression in different tissues was compared between asthmatic children and healthy control subjects in order to identify DEGs associated with asthma. Protein-protein interaction (PPI) networks were constructed for the DEGs and weighted gene co-expression network analysis methods were used to further determine the functional modules associated with DEGs in different tissue samples. In addition, the gene co-expression network was constructed. Gene Ontology function analysis and pathway analysis were conducted to identify critical DEGs. The results identified numerous DEGs from the different tissue samples, including 1,662 DEGs from nasal-epithelium tissue samples, 572 DEGs from peripheral blood (PB) samples and 146 DEGs from PB mononuclear cells samples. In the PPI network, F-box only protein 6 (FBXO6), histone deacetylase 1 (HDAC1) and amyloid β precursor protein (APP) were hub genes and served an important role in the process of asthma. In addition, proliferating cell nuclear antigen (PCNA), integrin α-4 (ITGA4), catenin α-1 (CTNNA1), nuclear factor-κB1 (NF-κB1) and mechanistic target of rapamycin (MTOR) may be critical DEGs involved in the progression of asthma in children. These results suggested that FBXO6, HDAC1 and APP may interact with PCNA, ITGA4, CTNNA1, NF-κB1 and mTOR in the progression of asthma in children.

Effects of IFN-γ on cell growth and the expression of ADAM33 gene in human embryonic lung Mrc-5 fibroblasts in vitro

OBJECTIVE

To investigate the effects of interferon-γ (IFN-γ) on the proliferation and viability of human embryonic lung Mrc-5 fibroblasts in vitro and the expression of the A Disintegrin and Metalloprotease 33 (ADAM33) gene and to explore the mechanism of airway remodeling.

METHODS

Mrc-5 fibroblasts were sensitized with Dermatophagoides farinae 1 (Derf1) in vitro to mimic in vivo conditions observed in bronchial asthma. An inverted fluorescence microscope was used to observe changes in cell morphology before and after treatment. The viability of Mrc-5 cells was tested using the Cell Counting kit-8 (CCK8). Expression of the ADAM33 gene and protein in Mrc-5 cells was assessed using qPCR and Western blotting, respectively.

RESULTS

Different concentrations of Derf1 increased cell growth and the expression of the ADAM33 gene in Mrc-5 cells, and these changes were most obvious in the 10 µg/ml group. In contrast, IFN-γ decreased cell growth and the expression of the ADAM33 gene in both Mrc-5 cells and Derf1-induced Mrc-5 cells, and these changes were most obvious in the 10 ng/ml group. The negative effects of 10 ng/ml IFN-γ were the most significant at 32 hours.

CONCLUSIONS

Derf1-induced Mrc-5 cells successfully imitated the in vivo conditions observed in patients with asthma. IFN-γ inhibited the proliferation and viability of Mrc-5 cells, and Derf1-induced Mrc-5 cells were more sensitive to IFN-γ treatment. IFN-γ treatment significantly downregulated the expression of the ADAM33 gene in a concentration- and time-dependent manner. IFN-γ may participate in airway remodeling in asthma by regulating the expression of the ADAM33 gene.

IL4Rα and ADAM33 as genetic markers in asthma exacerbations and type-2 inflammatory endotype

BACKGROUND

Genetic markers of susceptibility to asthma exacerbations in adults remain unclear.

OBJECTIVE

To identify genetic markers of asthma exacerbations, particularly in patients with type-2 inflammatory endotype.

METHODS

In this observational study of patients enrolled in the Kinki Hokuriku Airway disease Conference multicenter study, frequency of exacerbations requiring systemic corticosteroids during 2 years after enrolment and associated risk factors was determined. For genetic marker analysis, interleukin-4 receptor α (IL4RA) rs8832 and a disintegrin and metalloprotease 33 (ADAM33) S_2 (rs528557), T_1 (rs2280091), T_2 (rs2280090), and V_4 (rs2787094) variants were included. Elevated serum periostin levels at enrolment (≥95 ng/mL, defined as type-2 inflammatory endotype) were considered in the analysis.

RESULTS

Among 217 patients who were successfully followed up for 2 years after enrolment, 60 patients showed at least one asthma exacerbation during the 2 years. Airflow limitation (%FEV₁ <80%) and recent exacerbations but not genetic variants were identified as risk markers of exacerbations. A total of 27 patients showed type-2 inflammatory endotype (serum periostin ≥95 ng/mL at enrolment) and subsequent exacerbations; risk factors in these patients were airflow limitation (odds ratio, 6.51; 95% confidence interval (CI): 2.37-18.6; P=.0003), GG genotype of IL4RA rs8832 (odds ratio, 4.01; 95% CI: 1.47-11.0; P=.007), and A allele of ADAM33 T_2 (odds ratio, 2.81; 95% CI: 1.05-7.67; P=.04) by multivariate analysis. In addition, GG genotype of IL4RA rs8832 was associated with type-2 endotype, whereas A allele of ADAM33 T_2 was associated with mixed type of eosinophilic/type-2 and neutrophilic inflammations.

CONCLUSIONS AND CLINICAL RELEVANCE

IL4RA and ADAM33 variants may be risk markers of asthma exacerbations in type-2 inflammatory endotype. Precise endotyping may facilitate the identification of genetic risk markers of asthma exacerbations.