The role of SPINK5 in asthma related physiological events in the airway epithelium

Perinatal Exposure to Nicotine Alters Sperm RNA Profiles in Rats

Perinatal exposure to smoking has been associated with childhood asthma, one of the most common pediatric conditions affecting millions of children globally. Of great interest, this disease phenotype appears heritable as it can persist across multiple generations even in the absence of persistent exposure to smoking in subsequent generations. Although the molecular mechanisms underlying childhood asthma induced by perinatal exposure to smoking or nicotine remain elusive, an epigenetic mechanism has been proposed, which is supported by the data from our earlier analyses on germline DNA methylation (5mC) and histone marks (H3 and H4 acetylation). To further investigate the potential epigenetic inheritance of childhood asthma induced by perinatal nicotine exposure, we profiled both large and small RNAs in the sperm of F1 male rats. Our data revealed that perinatal exposure to nicotine leads to alterations in the profiles of sperm-borne RNAs, including mRNAs and small RNAs, and that rosiglitazone, a PPARγ agonist, can attenuate the effect of nicotine and reverse the sperm-borne RNA profiles of F1 male rats to close to placebo control levels.

CEBPB knockdown sensitizes nasopharyngeal carcinoma cells to cisplatin by promoting the expression of serine protease inhibitor Kazal-type 5

Serine protease inhibitor Kazal-type 5 (SPINK5) has been indicated to act as a prognostic predictor for patients with head and neck squamous cell carcinoma. However, its specific role in nasopharyngeal carcinoma (NPC), a malignancy that has a high propensity for chemoresistance, remains largely obscure. We, thus, sought to investigate the importance of SPINK5 expression in regulating chemoresistance in NPC. Differentially expressed genes in NPC were screened using the cancer genome atlas-head and neck squamous cell carcinoma database and microarray analysis. SPINK5 was downregulated in NPC tissues and cells. After SPINK5 upregulation, the cells treated with cisplatin showed reduced cell survival and the ability to migrate, invade and metastasize. Mechanistically, the transcription factors regulating SPINK5 were queried through the JASPAR website, followed by dual-luciferase and Chromatin immunoprecipitation assay validation. CCAAT enhancer-binding protein (CEBP) beta (CEBPB) bound to the SPINK5 promoter region in NPC cells. The silencing of CEBPB enhanced the expression of SPINK5. CEBPB overexpression reversed the inhibitory effects of cisplatin on NPC cell malignant phenotype in the presence of SPINK5 overexpression. In conclusion, CEBPB silencing promoted chemoresistance of NPC cells via activating SPINK5, signifying that targeting CEBPB was a new approach to enhance the chemotherapy efficacy in NPC.

Atopic dermatitis: Role of the skin barrier, environment, microbiome, and therapeutic agents

Atopic dermatitis (AD) is a chronic, inflammatory skin disorder characterized by eczematous and pruritic skin lesions. In recent decades, the prevalence of AD has increased worldwide, most notably in developing countries. The enormous progress in our understanding of the complex composition and functions of the epidermal barrier allows for a deeper appreciation of the active role that the skin barrier plays in the initiation and maintenance of skin inflammation. The epidermis forms a physical, chemical, immunological, neuro-sensory, and microbial barrier between the internal and external environment. Not only lesional, but also non-lesional areas of AD skin display many morphological, biochemical and functional differences compared with healthy skin. Supporting this notion, genetic defects affecting structural proteins of the skin barrier, including filaggrin, contribute to an increased risk of AD. There is evidence to suggest that natural environmental allergens and man-made pollutants are associated with an increased likelihood of developing AD. A compromised epidermal barrier predisposes the skin to increased permeability of these compounds. Numerous topical and systemic therapies for AD are currently available or in development; while anti-inflammatory therapy is central to the treatment of AD, some existing and novel therapies also appear to exert beneficial effects on skin barrier function. Further research on the skin barrier, particularly addressing epidermal differentiation and inflammation, lipid metabolism, and the role of bacterial communities for skin barrier function, will likely expand our understanding of the complex etiology of AD and lead to identification of novel targets and the development of new therapies.

A Novel Tumor Suppressor SPINK5 Serves as an Independent Prognostic Predictor for Patients with Head and Neck Squamous Cell Carcinoma

BACKGROUND

In our previous study, serine protease inhibitor Kazal-type 5 (SPINK5), which encodes the product of serine protease inhibitor lymphoepithelial Kazal-type-related inhibitor (LEKTI) was found to be down-regulated in head and neck squamous cell carcinoma (HNSCC) using oligonucleotide microarrays. However, the function and clinical implications of SPINK5/LEKTI remain obscure in HNSCC.

METHODS

The endogenous expression level of SPINK5/LEKTI was further verified in 9 HNSCC cell lines and HNSCCs by means of reverse transcription-polymerase chain reaction, real-time PCR, Western blotting and immunohistochemistry. The biological function of SPINK5/LEKTI was investigated in vitro and in vivo experiments. Kaplan-Meier survival analysis and Cox proportional hazards regression model were used to determine the correlation between SPINK5/LEKTI expression and clinical outcome.

RESULTS

Down-regulation expression of SPINK5/LEKTI was found in six out of nine HNSCC cell lines and in 85.7% HNSCC specimens (P<0.0001). Upon silencing of SPINK5/LEKTI, the cell proliferation, plate colony formation and cell invasion of WU-HN6 cells were significantly increased, while exogenous overexpression of SPINK5/LEKTI, the proliferation, plate colony and invasion of WU-HN13 and HN30 cells were remarkably inhibited with the arrest of G1 cell cycle (P=0.0001, P=0.003, respectively). HNSCC patients with lower LEKTI levels had significantly inferior overall survival compared to those patients with higher LEKTI (P=0.0017) by Kaplan-Meier survival analysis. Univariate and multivariate Cox proportional hazards regression model analysis revealed that LEKTI expression was an independent prognostic predictor for HNSCC patients (HR=0.114, 95% CI:0.044-0.292, P<0.001).

CONCLUSION

Our results demonstrate that SPINK5/LEKTI might be a tumor suppressor in HNSCCs and serve as an independent prognostic predictor for HNSCC patients.

Asthma: An Undermined State of Immunodeficiency

Asthma is a heterogeneous chronic respiratory disease characterized by an increased burden of infections. Respiratory tract infections associated with an increased risk for asthma especially when occurring in the first months of life, also represent the most common cause of asthma exacerbations. The association between asthma and the increased frequency of infections and microbiota dysbiosis might be explained by a common mechanism, such as an underlying immune system defect. Apart from the well-established association between primary immunodeficiencies and asthma, several alterations in the immune response following infection have also been observed in asthmatic patients. An impairment in lung epithelial barrier integrity exists and is associated with both an increased susceptibility to infections and the development of asthma. Asthmatic patients are also found to have a deficient interferon (IFN) response upon infection. Additionally, defects in Toll-like receptor (TLR) signaling are observed in asthma and are correlated with both recurrent infections and asthma development. In this review, we summarize the common pathophysiological background of asthma and infections, highlighting the importance of an underlying immune system defect that predispose individuals to recurrent infections and asthma.

Variation in doses and duration of particulate matter exposure in bronchial epithelial cells results in upregulation of different genes associated with airway disorders

Exposure to particulate matter < 2.5 μm (PM2.5) is associated with a variety of airway diseases. Although studies have demonstrated that high doses of PM2.5 cause cytotoxicity and changes to gene expression in bronchial epithelial cells, the effect of lower doses and repeated exposure to PM2.5 are less well studied. Here, we treated BEAS-2B cells with varying doses of PM2.5 for 1-7 days and examined the expression of a variety of genes implicated in airway disorders. At high doses, PM2.5 increased the expression of IL6, TNF, TSLP, CSF2, PTGS2, IL4R, and SPINK5. Other genes such as ADAM33, ORMDL3, DPP10 and CYP1A1, however, were increased by PM2.5 at much lower doses (≤1 μg/cm2). Repeated exposure to PM2.5 at 1 or 5 μg/cm2 every day for 7 days increased the sensitivity and magnitude of change for all of the aforementioned genes. Genes such as IL13 and TGFB1, increased only when cells were repeatedly exposed to PM2.5. Treatment with an antioxidant, or inhibitors to aryl hydrocarbon receptor or NF-κB attenuated the effect of PM2.5. These data demonstrate that PM2.5 exerts pleiotropic actions that differ by dose and duration that affect a variety of genes important to the development of airway disease.

Rhinovirus infection results in stronger and more persistent genomic dysregulation: Evidence for altered innate immune response in asthmatics at baseline, early in infection, and during convalescence

BACKGROUND

Rhinovirus (HRV) is associated with the large majority of virus-induced asthma exacerbations in children and young adults, but the mechanisms remain poorly defined.

METHODS

Asthmatics and non-asthmatic controls were inoculated with HRV-A16, and nasal epithelial samples were obtained 7 days before, 36 hours after, and 7 days after viral inoculation. RNA was extracted and subjected to RNA-seq analysis.

RESULTS

At baseline, 57 genes were differentially expressed between asthmatics and controls, and the asthmatics had decreased expression of viral replication inhibitors and increased expression of genes involved in inflammation. At 36 hours (before the emergence of peak symptoms), 1329 genes were significantly altered from baseline in the asthmatics compared to 62 genes in the controls. At this time point, asthmatics lacked an increase in IL-10 signaling observed in the controls. At 7 days following HRV inoculation, 222 genes were significantly dysregulated in the asthmatics, whereas only 4 genes were dysregulated among controls. At this time point, the controls but not asthmatics demonstrated upregulation of SPINK5.

CONCLUSIONS

As judged by the magnitude and persistence of dysregulated genes, asthmatics have a substantially different host response to HRV-A16 infection compared with non-asthmatic controls. Gene expression differences illuminate biologically plausible mechanisms that contribute to a better understanding of the pathogenesis of HRV-induced asthma exacerbations.

SPINK5 and ADRB2 haplotypes are risk factors for asthma in Mexican pediatric patients

BACKGROUND

Asthma is one of the most common respiratory diseases worldwide, and the complexity of its etiology has been widely documented. Chromosome 5q31-33 is one of the main loci implicated in asthma and asthma-related traits. IL13, CD14 and ADRB2, which are located in this risk locus, are among the genes most strongly associated with asthma susceptibility.

OBJECTIVES

This study evaluated whether single-nucleotide polymorphisms or haplotypes at 5q31-33 conferred risk for asthma in Mexican-Mestizo pediatric patients.

METHODS

We performed a case-controlled study including 851 individuals, 421 of them affected with childhood-onset asthma and 430 ethnically matched unaffected subjects. We used the TaqMan Allelic Discrimination Assay to genotype 20 single-nucleotide polymorphisms within IL5, RAD50, IL13, IL4, CD14, SPINK5, HTR4, ADRB2 and IL12B.

RESULTS

Although no association was detected for any risk allele, three SPINK5 haplotypes (GGCT: p = 6 × 10(-6); AATC: p = 0.0001; AGTT: p = 0.0001) and five ADRB2 haplotypes (AGGACC: p = 0.0014; AGGAAG: p = 0.0002; TGAGAG: p = 0.0001; AGGAAC: p = 0.0002; AAGGAG: p = 0.003) were associated with asthma. Notably, the AGTT SPINK5 haplotype exhibited a male gender-dependent association (p = 7.6 × 10(-5)).

CONCLUSION

Our results suggest that SPINK5 and ADRB2 haplotypes might play a role in the susceptibility to childhood-onset asthma.

Epistasis between serine protease inhibitor Kazal-type 5 (SPINK5) and thymic stromal lymphopoietin (TSLP) genes contributes to childhood asthma

BACKGROUND

Epithelial genes have previously been associated with asthma but only explain a small fraction of heritability. In part, this might be due to epistasis, which is often not considered.

OBJECTIVE

We sought to determine independent and epistatic associations between filaggrin (FLG), serine protease inhibitor Kazal-type 5 (SPINK5), and thymic stromal lymphopoietin (TSLP) gene variants and childhood asthma.

METHODS

Using a candidate gene approach, we genotyped 29 variants in FLG, SPINK5, and TSLP in asthmatic, allergic, and nonallergic nonasthmatic white and black children participating in the well-phenotyped Greater Cincinnati Pediatric Clinic Repository. Associations with asthma were also assessed in 6 replication populations.

RESULTS

We observed independent associations of variants in SPINK5 (P = .003) and TSLP (P = .006) with childhood asthma; a SPINK5 single nucleotide polymorphism was replicated. In subjects with 1 or more SPINK5 risk alleles, the absence of the TSLP protective minor alleles was associated with a significant increase in asthma (67% vs 53%, P = .0017). In contrast, the presence or absence of TSLP minor alleles did not affect asthma risk in subjects without the SPINK5 risk alleles. The SPINK5 and TSLP epistasis was replicated in a black population (P = .036) who did not display independent association with variants in these genes.

CONCLUSIONS

Our results support epistasis between SPINK5 and TSLP, which contributes to childhood asthma. These findings emphasize the importance of using biology to inform analyses to identify genetic susceptibility to complex diseases. The results from our study have clinical relevance and support that the therapeutic effects of anti-TSLP therapy in asthmatic patients might be dependent on SPINK5 genotype.

The impact of allergic rhinitis and asthma on human nasal and bronchial epithelial gene expression

Background

The link between upper and lower airways in patients with both asthma and allergic rhinitis is still poorly understood. As the biological complexity of these disorders can be captured by gene expression profiling we hypothesized that the clinical expression of rhinitis and/or asthma is related to differential gene expression between upper and lower airways epithelium.

Objective

Defining gene expression profiles of primary nasal and bronchial epithelial cells from the same individuals and examining the impact of allergic rhinitis with and without concomitant allergic asthma on expression profiles.

Methods

This cross-sectional study included 18 subjects (6 allergic asthma and allergic rhinitis; 6 allergic rhinitis; 6 healthy controls). The estimated false discovery rate comparing 6 subjects per group was approximately 5%. RNA was extracted from isolated and cultured epithelial cells from bronchial brushings and nasal biopsies, and analyzed by microarray (Affymetrix U133+ PM Genechip Array). Data were analysed using R and Bioconductor Limma package. For gene ontology GeneSpring GX12 was used.

Results

The study was successfully completed by 17 subjects (6 allergic asthma and allergic rhinitis; 5 allergic rhinitis; 6 healthy controls). Using correction for multiple testing, 1988 genes were differentially expressed between healthy lower and upper airway epithelium, whereas in allergic rhinitis with or without asthma this was only 40 and 301 genes, respectively. Genes influenced by allergic rhinitis with or without asthma were linked to lung development, remodeling, regulation of peptidases and normal epithelial barrier functions.

Conclusions

Differences in epithelial gene expression between the upper and lower airway epithelium, as observed in healthy subjects, largely disappear in patients with allergic rhinitis with or without asthma, whilst new differences emerge. The present data identify several pathways and genes that might be potential targets for future drug development.

Factors that predict the clinical reactivity and tolerance in children with cow's milk allergy

BACKGROUND

Specific IgE (sIgE) may be used for the diagnosis of cow's milk allergy (CMA) and as a guide to perform food challenge tests in patients with CMA. The effect of genetic variants on the prognosis of food allergy is largely unknown.

OBJECTIVE

To examine the performance of sIgE analysis and the utility of the genetic variants of CD14, STAT6, IL13, IL10, SPINK5, and TSLP in predicting the clinical course in children with CMA.

METHODS

Serum sIgE levels of 94 children who underwent open food challenges and 54 children with anaphylaxis due to cow's milk (CM) were retrospectively analyzed between January 2002 and May 2009. The genetic polymorphisms were determined in 72 children.

RESULTS

A total of 148 children were followed up for a median of 3.5 years, and 42 of the 94 challenge results were positive. The probability curves with 95% decision points were 2.8 kU/L for younger than 1 year, 11.1 for younger than 2 years, 11.7 for younger than 4 years, and 13.7 for younger than 6 years. Sixty-six children outgrew CMA during follow-up. Children with initial an CM sIgE level less than 6 kU/L outgrew CMA earlier than children with an initial CM sIgE level of 6 kU/L or higher (P < .001). The age of tolerance development for CM was significantly higher in children with the GG genotype at rs324015 of the STAT6 gene compared with those with the AA+AG genotype (2 years [range, 1.5-3.9 years] vs 1.2 years [range, 1.0-2.2 years]) (P = .02).

CONCLUSION

The decision points of sIgE obtained in different age groups may help to determine the likelihood of clinical reactivity more precisely. The results suggest that sIgE levels and STAT6 gene variants may be important determinants to predict longer persistence of CMA.

The role of SCCA1 in asthma related physiological events in the airway epithelium and the effect of promoter variants on asthma and gene function

BACKGROUND

Even though the systemic level of SCCA1, a serine protease inhibitor, was shown to be elevated in asthma, its physiological role is unknown.

OBJECTIVE

We sought to determine the effect of SCCA1 on apoptosis, cytokine expression and mucus production by A549 cells and define the effect of promoter variants on gene expression and association with asthma.

METHODS

SCCA levels were measured by ELISA. Promoter variants were determined by direct sequencing. 442 asthmatic children and 191 controls were genotyped by RFLP. The functional effect of the polymorphisms was assessed in transient transfection experiments using reporter constructs. A transcription factor ELISA was used for differential binding of GATA proteins to the variant region. The effects of SCCA1 on cytokine synthesis, mucus production and apoptosis were determined in A549 cells transfected with SCCA1 pcDNA vector. MUC5AC expression in A549 cells was determined with RT-PCR.

RESULTS

SCCA1 protein level was significantly higher in asthmatic children compared to healthy controls. Four polymorphisms SCCA1 promoter that were in linkage disequilibrium were associated with skin test positivity in asthmatic children and showed higher promoter activity and higher binding of GATA-2 and GATA-3 after IL-4 + IL-13 stimulation. IL-6, IL-8 levels were significantly higher in cells transfected with SCCA1 whereas RANTES increased only after IL-4 stimulation. Transfection of A549 cells with SCCA1 resulted in decreased MUC5AC expression and conferred protection against apoptosis.

CONCLUSION

Our results showed that SCCA1 has diverse effects on many of the cellular events that characterize asthma and its role extends beyond protease inhibition.