Fatty acid binding protein 1 is related with development of aspirin-exacerbated respiratory disease

Long-Term Cryopreservation of Nasal Polyp Tissue in a Biobank for the Isolation and Culture of Primary Epithelial Cells

Epithelial cells may play an important role in the pathologic process of chronic rhinosinusitis with nasal polyps. Therefore, providing epithelial cells from a biobank could greatly contribute to further research. In the present work, the isolation of epithelial cells from long-term cryopreserved tissue is demonstrated. Polyp tissues were cryopreserved in a commercially available freezing medium with dimethyl sulfoxide and stored in liquid nitrogen. The outgrowth and proliferation of epithelial cells from cryopreserved tissue were evaluated and compared to that of fresh tissue. Flow cytometric analysis with anti-cytokeratin, anti-p63, and anti-Ki-67 was performed to identify epithelial cells and determine differentiation and proliferation. A functionality test was performed by determining type 2–relevant proteins, representatively thymic stromal lymphopoietin (TSLP) and periostin, using ELISA. Primary epithelial cells could be isolated from cryopreserved tissues. Cells from cryopreserved tissues showed comparable outgrowth and proliferation to that of fresh tissue. Isolated epithelial cells showed high cytokeratin, p63, and Ki-67 expression and secreted TSLP and periostin. In the present study, a method for long-term cryopreservation of polyp tissue was established, thereby enabling the isolation and cell culture of primary cell culture at a later time. Epithelial cell availability should be greatly improved by including this method in a biobank.

Current Insights on the Impact of Proteomics in Respiratory Allergies

Respiratory allergies affect humans worldwide, causing extensive morbidity and mortality. They include allergic rhinitis (AR), asthma, pollen food allergy syndrome (PFAS), aspirin-exacerbated respiratory disease (AERD), and nasal polyps (NPs). The study of respiratory allergic diseases requires new technologies for early and accurate diagnosis and treatment. Omics technologies provide the tools required to investigate DNA, RNA, proteins, and other molecular determinants. These technologies include genomics, transcriptomics, proteomics, and metabolomics. However, proteomics is one of the main approaches to studying allergic disorders' pathophysiology. Proteins are used to indicate normal biological processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention. In this field, the principal goal of proteomics has been to discover new proteins and use them in precision medicine. Multiple technologies have been applied to proteomics, but that most used for identifying, quantifying, and profiling proteins is mass spectrometry (MS). Over the last few years, proteomics has enabled the establishment of several proteins for diagnosing and treating respiratory allergic diseases.

Association analysis of ILVBL gene polymorphisms with aspirin-exacerbated respiratory disease in asthma

Background

We previously reported that the ILVBL gene on chromosome 19p13.1 was associated with the risk for aspirin-exacerbated respiratory disease (AERD) and the percent decline of forced expired volume in one second (FEV1) after an oral aspirin challenge test. In this study, we confirmed the association between polymorphisms and haplotypes of the ILVBL gene and the risk for AERD and its phenotype.

Methods

We recruited 141 AERD and 995 aspirin-tolerant asthmatic (ATA) subjects. All study subjects underwent an oral aspirin challenge (OAC). Nine single nucleotide polymorphisms (SNPs) with minor allele frequencies above 0.05, which were present in the region from 2 kb upstream to 0.5 kb downstream of ILVBL in Asian populations, were selected and genotyped.

Results

In an allelic association analysis, seven of nine SNPs were significantly associated with the risk for AERD after correction for multiple comparisons. In a codominant model, the five SNPs making up block2 (rs2240299, rs7507755, rs1468198, rs2074261, and rs13301) showed significant associations with the risk for AERD (corrected P = 0.001–0.004, OR = 0.59–0.64). Rs1468198 was also significantly associated with the percent decline in FEV1 in OAC tests after correction for multiple comparisons in the codominant model (corrected P = 0.033), but the other four SNPs in hapblock2 were not.

Conclusion

To the best of our knowledge, this is the first report of an association between SNPs on ILVBL and AERD. SNPs on ILVBL could be promising genetic markers of this condition.

Electronic supplementary material

The online version of this article (10.1186/s12890-017-0556-6) contains supplementary material, which is available to authorized users.

Aspirin induces IL-4 production: augmented IL-4 production in aspirin-exacerbated respiratory disease

Aspirin hypersensitivity is a hallmark of aspirin-exacerbated respiratory disease (AERD), a clinical syndrome characterized by the severe inflammation of the respiratory tract after ingestion of cyclooxygenase-1 inhibitors. We investigated the capacity of aspirin to induce interleukin-4 (IL-4) production in inflammatory cells relevant to AERD pathogenesis and examined the associated biochemical and molecular pathways. We also compared IL-4 production in peripheral blood mononuclear cells (PBMCs) from patients with AERD vs aspirin-tolerant asthma (ATA) upon exposure to aspirin. Aspirin induced IL-4 expression and activated the IL-4 promoter in a report assay. The capacity of aspirin to induce IL-4 expression correlated with its activity to activate mitogen-activated protein kinases, to form DNA-protein complexes on P elements in the IL-4 promoter and to synthesize nuclear factor of activated T cells, critical transcription factors for IL-4 transcription. Of clinical importance, aspirin upregulated IL-4 production twice as much in PBMCs from patients with AERD compared with PBMCs from patients with ATA. Our results suggest that IL-4 is an inflammatory component mediating intolerance reactions to aspirin, and thus is crucial for AERD pathogenesis.

Level of Fatty Acid Binding Protein 5 (FABP5) Is Increased in Sputum of Allergic Asthmatics and Links to Airway Remodeling and Inflammation

BACKGROUND

The inflammatory processes in the upper and lower airways in allergic rhinitis and asthma are similar. Induced sputum and nasal lavage fluid provide a non-invasive way to examine proteins involved in airway inflammation in these conditions.

OBJECTIVES

We conducted proteomic analyses of sputum and nasal lavage fluid samples to reveal differences in protein abundances and compositions between the asthma and rhinitis patients and to investigate potential underlying mechanisms.

METHODS

Induced sputum and nasal lavage fluid samples were collected from 172 subjects with 1) allergic rhinitis, 2) asthma combined with allergic rhinitis, 3) nonallergic rhinitis and 4) healthy controls. Proteome changes in 21 sputum samples were analysed with two-dimensional difference gel electrophoresis (2D-DIGE), and the found differentially regulated proteins identified with mass spectrometry. Immunological validation of identified proteins in the sputum and nasal lavage fluid samples was performed with Western blot and ELISA.

RESULTS

Altogether 31 different proteins were identified in the sputum proteome analysis, most of these were found also in the nasal lavage fluid. Fatty acid binding protein 5 (FABP5) was up-regulated in the sputum of asthmatics. Immunological validation in the whole study population confirmed the higher abundance levels of FABP5 in asthmatic subjects in both the sputum and nasal lavage fluid samples. In addition, the vascular endothelial growth factor (VEGF) level was increased in the nasal lavage fluid of asthmatics and there were positive correlations between FABP5 and VEGF levels (r=0.660, p<0.001) and concentrations of FABP5 and cysteinyl leukotriene (CysLT) (r=0.535, p<0.001) in the nasal lavage fluid.

CONCLUSIONS

FABP5 may contribute to the airway remodeling and inflammation in asthma by fine-tuning the levels of CysLTs, which induce VEGF production.

Changes in FABP1 and gastrin receptor expression in the testes of rats that have undergone electrical injury

Testicular trauma may occur due to accidental electrical injury. The aim of this study was to investigate alterations in the levels of fatty acid-binding protein 1 (FABP1) and gastrin receptor (gastrin R) in the testes following electrical injury. Sprague-Dawley rats were divided into control, fatal electrocution (220 V, 50 Hz, 60 sec) and electrical injury (220 V, 50 Hz, 60 sec) groups (n=8 per group). The animals in the fatal electrocution and electrical injury groups were deeply anesthetized with sodium pentobarbital prior to each treatment, in which the current was delivered via an anode connected to the left foreleg and a cathode to the right hindleg. The rats that survived were subsequently sacrificed by cervical dislocation. Control animals received cervical dislocation alone. Immunohistochemical analysis was performed to evaluate the protein expression of FABP1 and gastrin R in the testes. Sections were evaluated by digital image analysis. The expression levels of FABP1 and gastrin R were significantly increased following electrical injury, supported by an increase in the integrated optical density (IOD) when compared with that in the control group (P<0.05). However, no significant difference was found in FABP1 and gastrin R expression levels between the fatal electrocution and control groups. In summary, the protein expression levels of FABP1 and gastrin R were found to be significantly altered by electrical injury, suggesting that these two proteins may be important in underlying mechanisms of testicular injury during electrical injury. The findings indicate that such alterations would be reflected in abnormal testicular function.

Respiratory proteomics: from descriptive studies to personalized medicine

Respiratory diseases are highly prevalent and affect humankind worldwide, causing extensive morbidity and mortality with the environment playing an important role. Given the complex structure of the airways, sophisticated tools are required for early diagnosis; initial symptoms are nonspecific, and the clinical diagnosis is made frequently late. Over the past few years, proteomics has made high technological progress in mass-spectrometry-based protein identification and has allowed us to gain new insights into disease mechanisms and identify potential novel therapeutic targets. This review will highlight the contributions of proteomics toward the understanding of the respiratory proteome listing potential biomarkers and its potential application to the clinic. We also outline the contributions of proteomics to creating a personalized approach in respiratory medicine.

Association analysis of FABP1 gene polymorphisms with aspirin-exacerbated respiratory disease in asthma

Previously, we used a proteomic approach to demonstrate that the protein level of fatty acid-binding protein 1 (FABP1) is increased in nasal polyps in patients with aspirin-exacerbated respiratory disease (AERD). To reveal the genetic effect of FABP1 variants, we evaluated the association of FABP1 polymorphisms with the risk of AERD in 207 asthmatics with AERD and 1019 aspirin-tolerant asthmatics (ATA). Seven polymorphisms of FABP1 were selected from the National Center for Biotechnology Information (build 36) using minor allele frequency and linkage disequilibrium criteria. The genotype and haplotype distributions were not significantly different between the AERD and ATA groups in all of the genetic models. The percent decline of forced expiratory volume in 1 second (FEV1) after the oral aspirin challenge (OAC) test did not differ according to single-nucleotide polymorphism (SNP) genotypes. In haplotype analysis, asthmatic patients who were BL2ht2 homozygotes showed a greater decline in FEV1 after the OAC test than subjects who possessed 1 or no copy of BL2ht2 (P = 0.035). However, these observations were not significant after correction for multiple comparisons (corrected P value = 1.00). Neither genotype nor haplotype was associated with the presence of nasal polyposis in the study subjects. Although we did not find a significant association between the FABP1 polymorphisms and AERD, our data suggest that the 7 SNPs are not associated with the increased expression of FABP1 in asthmatic patients with AERD. Further studies of epigenetic factors that may contribute to the increased expression of FABP1 in AERD should be performed.

Eosinophil activation and novel mediators in the aspirin-induced nasal response in AERD

BACKGROUND

Eosinophil activation is the key feature of upper and lower airway inflammation in aspirin-exacerbated respiratory disease (AERD).

OBJECTIVE

To investigate the mechanism of eosinophil activation and identify novel inflammatory mediators using proteomics.

METHODS

Thirty-two asthmatic subjects were enrolled: 18 AERD patients who showed positive responses to the lysine-aspirin nasal provocation test (L-ASA NPT) and 14 aspirin-tolerant asthma (ATA) patients who showed negative responses to the L-ASA NPT (control group). Nasal lavage fluid (NLF) was collected before (baseline), at 10, 30 and 60 min (early response), and at 3 h (late response) after the L-ASA NPT. Eosinophil cationic protein (ECP) and cysteinyl leucotriene (CysLT) levels were measured using an ImmunoCAP system and ELISA respectively. To identify proteins involved in AERD, comparative proteomics was applied using NLFs collected before and after L-ASA NPTs in AERD patients. The clinical relevance of identified novel proteins was evaluated by ELISA using NLFs from the AERD and ATA groups.

RESULTS

Eosinophil cationic protein and CysLT levels both increased significantly during the early response in AERD. ECP levels increased until the late response in AERD, while CysLT levels were not significantly increased during the late response. Proteomic analysis showed up-regulation of apolipoprotein A1 (ApoA1), α2-macroglobulin (α2M) and ceruloplasmin (CP), with significant increases in NLF of AERD patients, which was significantly higher in AERD patients with chronic rhinosinusitis. Significant correlations were noted between ECP and CysLT, ApoA1, α2M and CP levels during the early response in AERD patients.

CONCLUSION

Eosinophil activation occurred in early and late responses after L-ASA NPT in upper airway mucosa of AERD patients, where ApoA1, α2M and CP as well as CysLT may be involved in eosinophilic inflammation.