Increased apoptosis of peripheral blood mononuclear cells in patients with perennial allergic asthma/rhinitis: relation to serum markers of apoptosis

5-Hydroxymethylfurfural Ameliorates Allergic Inflammation in HMC-1 Cells by Inactivating NF-κB and MAPK Signaling Pathways

Allergic inflammation is the foundation of multiple allergic disorders, such as allergic rhinitis and asthma. Mast cells are effector cells that initiate inflammatory response. 5-hydroxymethylfurfural (5-HMF), a furfural compound, is the heat-processed product of various fruit, foods, drinks, as well as some Chinese herbal medicines. 5-HMF was previously reported to inhibit mast cell activation. Our study aimed to explore the functions of 5-HMF in both phorbol 12-mystate 13-acetate (PMA) plus calcium ionophore (A23187)-induced allergic inflammation in human mast cell line HMC-1 and ovalbumin (OVA)-induced asthma mouse models. HMC-1 cells were pretreated with 5-HMF and then stimulated by PMA+A23187. The cytotoxicity of 5-HMF on HMC-1 cells was evaluated by MTT assay. Histamine content in cell supernatants was measured by the o-phthaldialdehyde spectrofluorometric procedure. Intracellular calcium was determined using the fluorescent dye Fura-2AM. The production and expression of pro-inflammatory cytokines were detected by ELISA and RT-qPCR. Caspase-1 colorimetric assay was employed to examine the enzymatic activity of caspase-1. Asthma mouse models were induced by OVA sensitization. The bronchoalveolar lavage fluid (BALF) and blood samples were collected for the detection of total and differential cell count as well as aspartate aminotransferase (AST), alanine aminotransferase (ALT), OVA-immunoglobulin E (OVA-IgE), OVA-immunoglobulin G1 (OVA-IgG1), and pro-inflammatory cytokine levels. The left lung of mouse was dissected for histopathological examination by hematoxylin and eosin (H&E) staining. The protein expression of pro-caspase-1 and the phosphorylation of NF-κB and MAPK pathway-associated molecules were assessed by Western blotting. Our findings revealed that 5-HMF efficiently suppressed the PMA+A23187-induced enhancement in histamine production and intracellular calcium in HMC-1 cells. Pro-inflammatory cytokine production and expression in HMC-1 cells were elevated after PMA plus A23187 stimulation, which, however, were inhibited by pretreatment of 5-HMF. Additionally, 5-HMF suppressed the activity of caspase-1 and the phosphorylation of NF-κB and MAPK-associated molecules including p65 NF-κB, p38 MAPK, ERK, and JNK in HMC-1 cells. In vivo experiments demonstrated that 5-HMF treatment reduced the lung/body weight index and total and differential (macrophages, neutrophils, lymphocytes, and eosinophils) cell counts in BALF of asthmatic mice, but exerted no influence on serum AST and ALT levels. Besides, 5-HMF reduced serum OVA-IgE and OVA-IgG1 levels, mitigated lung inflammation, and inhibited the NF-κB and MAPK signaling pathways in asthma mouse models. 5-HMF mitigates allergic inflammation in asthma by inactivating caspase-1 and NF-κB and MAPK signaling pathways.

NLRP3 inflammasome: A likely target for the treatment of allergic diseases

Allergic diseases, such as asthma, rhinitis, dermatitis, conjunctivitis, and anaphylaxis, have recently become a global public health concern. According to previous studies, the NLRP3 inflammasome is a multi-protein complex known to be associated with many inflammatory conditions. In response to allergens or allergen/damage-associated molecular signals, NLRP3 changes its conformation to allow the assembly of the NLRP3 inflammasome complex and activates caspase-1, which is an evolutionarily conserved enzyme that proteolytically cleaves other proteins, such as the precursors of the inflammatory cytokines IL-1β and IL-18. Subsequently, active caspase-1 cleaves pro-IL-1 and pro-IL-18. Recently, accumulating human and mouse experimental evidence has demonstrated that the NLRP3 inflammasome, IL-1β, and IL-18 are critically involved in the development of allergic diseases. Furthermore, the application of specific NLRP3 inflammasome inhibitors has been demonstrated in animal models. Therefore, these inhibitors may represent potential therapeutic methods for the management of clinical allergic disorders. This review summarizes findings related to the NLRP3 inflammasome and its related factors and concludes that specific NLRP3 inflammasome inhibitors may be potential therapeutic agents for allergic diseases.

Cysteine ameliorates allergic inflammatory reactions by suppressing thymic stromal lymphopoietin production in activated human mast cells

Thymic stromal lymphopoietin (TSLP) derived by mast cells is recognized as a critical factor in many allergic inflammatory disorders. Cysteine is a well-known amino acid which exhibits anti-inflammatory activities. However, the effect and mechanism of cysteine on TSLP production have not been investigated. Thus, we hypothesized that cysteine may regulate TSLP production from mast cells. To test this hypothesis, the anti-inflammatory effects and signaling pathways of cysteine were investigated in phorbol 12-myristate 13-acetate 4 and calcium ionophore A23187 (PMACI)-stimulated human mast cell line HMC-1. Cysteine dramatically attenuated the levels of TSLP of both mRNA and protein without cytotoxicity. Moreover, cysteine suppressed caspase-1 activation and nuclear factor-κB translocation. The phosphorylation of p38 and c-Jun N-terminal kinase was downregulated in all cases in PMACI-stimulated HMC-1 cells treated with cysteine. In addition, cysteine decreased PMACI-induced proinflammatory cytokines in terms of both protein and mRNA levels. In conclusion, cysteine regulates TSLP production by blocking caspase-1, nuclear factor-κB, p38, and c-Jun N-terminal kinase-dependent pathways in activated HMC-1 cells, suggesting its potential as a regulator of allergic inflammatory diseases.

The potential protective role of taurine against experimental allergic inflammation

AIMS

Taurine has been widely evaluated as a potential therapeutic agent in chronic inflammatory disorders and various infections. However, the potential role of taurine in regulating allergic inflammatory responses is currently unknown.

MATERIALS AND METHODS

The present study was designed to evaluate the in vitro effects of taurine on the levels of thymic stromal lymphopoietin (TSLP) and other pro-inflammatory cytokines and activation of caspase-1 and nuclear factor (NF)-κB as well as the phosphorylations of c-Jun N-terminal kinase (JNK) and p38 in phorbol 12-myristate 13-acetate and calcium ionophore A23187 (PMACI)-triggered human mast cell line, HMC-1 cells. Furthermore, we assessed the therapeutic effects of taurine on ovalbumin (OVA)-induced allergic rhinitis (AR) animal models.

KEY FINDINGS AND SIGNIFICANCE

Here, the obtained results showed that taurine dose-dependently inhibited the production and mRNA expression of TSLP and pro-inflammatory cytokines in HMC-1 cells exposed to PMACI. Taurine attenuated the phosphorylation of JNK and p38 in activated HMC-1 cells. Moreover, taurine brought a significant inhibition of the activities of NF-κB and caspase-1. In an OVA-induced AR animal model, the increased levels of nose rubbing, histamine, immunoglobulin E, TSLP, and interleukin IL-1β were dramatically reduced by the administration of taurine. In summary, taurine could serve as potential novel remedy of allergic inflammatory disorders.

Activation of Bcl-2-Caspase-9 Apoptosis Pathway in the Testis of Asthmatic Mice

BACKGROUND

Apoptosis plays a critical role in controlling the proliferation and differentiation of germ cells during spermatogenesis. Dysregulation of the fine-tuned balance may lead to the onset of testicular diseases. In this study, we investigated the activation status of apoptosis pathways in the testicular tissues under the background of an asthmatic mouse model.

METHODS

Ten BALB/c mice were divided into two groups: the acute asthma group and the control group. In the acute asthma group, ovalbumin (OVA)-sensitized mice were challenged with aerosolized OVA for 7 days, while the control group was treated with physiological saline. After that, both epididymis and testis were collected to determine the sperm count and motility. Apoptosis in the testis was evaluated by DNA ladder, immunochemistry and further by PCR array of apoptosis-related genes. Finally, the cleavage of caspase-3 and poly ADP-ribose polymerase (PARP) was determined by western blot and the enzymatic activities of caspase-9 and 3/7 were assessed using Caspase-Glo kits.

RESULTS

Compared with control mice, significant decreases in the body weight, testis weight, sperm count and motility were seen in the experimental group. DNA ladder and immunochemistry showed significant increase in apoptotic index of the asthmatic testis, whereas a decrease in mRNA expression of Bcl-2 and increases in Bax, BNIP3, caspase-9, and AIF were observed in the asthma group. Furthermore, protein levels of AIF were significantly upregulated, while the translational expression of Bcl-2 was downregulated markedly. Consistently, caspase-9 activity in the testis of asthma mice was significantly higher than that of the control group.

CONCLUSION

Collectively, these results showed that Bcl-2-caspase-9 apoptosis pathway was clearly activated in the testis of asthmatic mice with the increased expression of apoptosis-related genes and proteins. To our knowledge, this is the first report demonstrating that asthma could lead to the activation of the mitochondrial apoptosis signaling pathway in the mouse testis.

Protein-protein interaction network analysis and identifying regulation microRNAs in asthmatic children

BACKGROUND

Asthma is a chronic inflammatory airway disease, the incidence of which has increased recently. In order to identify the potential biomarkers for allergic asthma therapy, microarray data were analysed to find meaningful information.

METHODS

Microarray data GSE18965 were downloaded from Gene Expression Ominibus (GEO), including seven asthmatic epithelium samples from children with allergic asthma and nine healthy controls. Limma package was used to detect differentially expressed genes (DEGs) and the criteria were |log fold change|>0.5 and p value<0.05. We used Database for Annotation, Visualization and Integrated Discovery (DAVID) tool to perform GO function and KEGG pathway analysis. STRING database was used to construct protein-protein interaction (PPI) network. MicroRNA (miRNA) regulation network was constructed according to miRecords database.

RESULTS

We identified 274 DEGs in asthma epithelium samples comparing with healthy controls. There were 123 up-regulated DEGs and 151 down-regulated DEGs. PPI network analysis showed that TSPO, G6PD and TXN had higher degree. miRNA regulation network demonstrated that miR-16 and miR-15a had higher degree. The target genes of miRNAs were significantly enriched in the apoptosis function.

CONCLUSIONS

TSPO, G6PD and TXN, miR-16, miR-15a and apoptosis may be used as the targets for children's allergic asthma therapy.

Allergen-specific immunotherapy increases plasma gelsolin levels

BACKGROUND

It has been observed that patients with allergic asthma/rhinitis have increased apoptosis of peripheral blood cells. This study was designed to explore the idea that the markers of apoptosis may help predict the response of allergen immunotherapy.

METHODS

The Allergy Department of University Hospital, Malmö, Sweden, recruited a total of 58 young adults (<35 years) with a history of birch pollen/grass pollen-induced allergic rhinitis. Their diagnoses were verified by positive skin-prick tests and the presence of serum-specific immunoglobulin E antibodies toward birch and/or grass pollen. Plasma samples were obtained from 34 patients before the start of immunotherapy and 24 patients after treatment. The control group consisted of 38 nonallergic individuals. The levels of plasma gelsolin, soluble forms of Fas (sFas) and Fas ligand (Fas-L), the chemokine CCL17 (thymus- and activation-regulated chemokine), and tissue inhibitor of metalloprotease (TIMP) 1, were measured by enzyme-linked immunosorbent assay.

RESULTS

In patients receiving immunotherapy plasma gelsolin levels were higher relative to those without immunotherapy (the median level was 23.97 μg/mL [range, 18-35.8 μg/mL] versus 21.2 μg/mL [range, 13.9-29.8 μg/mL]; p = 0.012) and were similar to those of healthy controls (24.7 μg/mL [range, 17.4-35.3 μg/mL]). Plasma levels of sFas, Fas-L, CCL17, and TIMP-1 did not differ between study groups. Only in controls did the plasma gelsolin levels inversely correlate to the levels of soluble Fas.

CONCLUSION

Allergen-specific immunotherapy increases plasma levels of gelsolin, an antioxidant and antiapoptotic protein.

cFLIP expression is altered in severe corticosteroid-resistant asthma

Dysregulation of alternative splicing of mRNA precursors is known to contribute to numerous human diseases. In this study we carried out the first systematic search for asthma-associated changes in alternative splicing events, using a model of Aspergillus fumigatus (A. fumigatus)-sensitized mice and an exon junction microarray to detect potential changes in alternative splicing. One of the sensitization-associated changes identified in the search was a shift in alternative splicing of the mRNA encoding cFLIP, a modulator of the caspase-mediated extrinsic apoptosis pathway. Expanding these studies to human asthma patients, we discovered a significant decrease in the expression of both cFLIP isoforms in severe corticosteroid-resistant asthmatics. Although it is unclear whether these changes were due solely to differences in alternative splicing, these findings provide evidence that dysregulation of the extrinsic apoptosis pathway is part of the underlying immunopathogenesis of severe refractory asthma.

Inhibition of IL-32 and TSLP production through the attenuation of caspase-1 activation in an animal model of allergic rhinitis by Naju Jjok (Polygonum tinctorium)

In this study, we investigated the effects of Naju Jjok (Polygonum tinctorium Lour., NJJ) on interleukin (IL)-32 and thymic stromal lymphopoietin (TSLP) levels associated with allergic rhinitis (AR). Using female BALB/c mice, we created an animal model of ovalbumin (OVA)-induced AR. Prior to the callenge with OVA, the mice were administered, either nasally or orally with NJJ. In addition, we also used the eosinophilic cells line, Eol-1, stimulated with granulocyte‑macrophage colony-stimulation factor (GM-CSF). The mRNA and protein levels of inflammatory cytokines and markers [interleukin (IL)-32, IL-4, macrophage-inflammatory protein-2 (MIP-2), intercellular adhesion molecule-1 (ICAM-1), and cyclooxygenase-2 (COX-2)] were measured by RT-PCR and western blot analysis, respectively and serum levels were measured by ELISA. The increased levels of IL-32 in the mice with AR and in the stimulated eosinophilic cell line, Eol-1, were significantly reduced by NJJ. TSLP levels were also decreased following the oral administration of NJJ. Mice orally administered NJJ showed markedly alleviated clinical symptoms, such as a reduced number of nasal rubs, decreased spleen weight, decreased serum immunoglobulin E (IgE) levels and decreased serum histamine levels. The oral administration of NJJ significantly decreased the IL-4 levels, while increasing the interferon-γ levels in the spleen. The increased number of eosinophils and mast cells infiltrating the nasal mucosal tissue of the mice with AR were decreased following the oral administration of NJJ. NJJ effectively attenuated caspase-1 activity in the mice with AR and in the stimulated Eol-1 cells. The oral administration of NJJ significantly reduced the levels of inflammatory markers, such as MIP-2, ICAM-1 and COX-2. Furthermore, the intranasal administration of NJJ significantly reduced the early phase response to allergen exposure, such as nasal rubs, IgE production and histamine release, as well as the late phase responses, such as the expression of inflammatory markers. In conclusion, these data demonstrate that NJJ may play a regulatory role in nasal inflammation.

Inactivation of cystein-aspartic acid protease (caspase)-1 by saikosaponin A

This work investigates the anti-inflammatory mechanism of saikosaponin A (SA), a major component of Bupleurum falcatum LINNE. SA significantly inhibited phorbol myristate acetate (PMA) plus A23187-induced the production and expression of interleukin (IL)-6 and tumor necrosis factor (TNF)-α in human mast cell (HMC)-1 cells. SA suppressed PMA plus A23187-induced phosphorylation of extracellular signal-regulated kinase and p38. When HMC-1 cells were treated with SA, translocation of nuclear factor (NF)-κB/Rel A into nucleus and degradation of inhibitor of NF-κB (IκB) in cytoplasm were inhibited. SA decreased PMA plus A23187-induced cysteine-aspartic acid protease (caspase)-1 activity. IL-1β production was also inhibited by SA. Finally, SA significantly decreased the number of nasal rubs and serum TNF-α level in the ovalbumin-sensitized allergic rhinitis mouse model. The underlying mechanism involves, at least in part, inactivation of caspase-1, which provides new evidence for therapeutic application of SA to target inflammatory processes.

Distinct effects of imperatorin on allergic rhinitis: imperatorin inhibits caspase-1 activity in vivo and in vitro

Because imperatorin (IPT), the furanocoumarins exhibits anti-inflammatory activity, we reasoned that IPT might modulate the allergic rhinitis (AR). The aim of this study was to analyze the regulation of AR by IPT. Here, we show the effect and mechanism of IPT in an ovalbumin (OVA)-induced AR model. The number of rubs after the OVA challenge in the OVA-sensitized mice was significantly higher than that in the OVA-unsensitized mice. The increased number of rubs was inhibited by the oral administration of IPT. The increased levels of IgE and histamine in the OVA-sensitized mice were reduced by IPT administration. The levels of interferon-γ were enhanced, whereas the levels of interleukin (IL)-4 were reduced on the spleen tissue of the IPT-administered AR mice. Protein levels of IL-1β, macrophage inflammatory protein-2, intercellular adhesion molecule-1, and cyclooxygenase-2 were reduced by IPT administration in the nasal mucosa of the OVA-sensitized mice. In the IPT-administered mice, the number of eosinophils and mast cells infiltration increased by OVA-sensitization were also decreased. In addition, IPT inhibited caspase-1 activity in the same nasal mucosa tissue. In activated human mast cells, the receptor-interacting protein 2 (RIP2), IκB kinase (IKK)-β, nuclear factor-κB (NF-κB)/RelA, and caspase-1 activation were increased, but increased RIP2, IKK-β, NF-κB/RelA, and caspase-1 activation were inhibited by the treatment of IPT. In addition, IPT inhibited caspase-1 activity and IL-1β production in IgE-stimulated bone marrow-derived mast cells. We can conclude that IPT exerts significant effects by regulating of caspase-1 activation in AR animal and in vitro models.

Nasal tactile sensitivity in allergic rhinitis

CONCLUSION

These preliminary data show a decrease in nasal tactile sensitivity and point out interesting aspects of the nasal chronic inflammatory condition in allergic rhinitis.

OBJECTIVES

The aim of this study was to evaluate the effects of allergic rhinitis on nasal tactile sensitivity during the intercritical period.

METHODS

A total of 70 patients aged between 18 and 67 years (average 42 years), with a positive history of allergy caused by seasonal outdoor allergens, were included (group A). Patient outcome was assessed by the nasal monofilament test: a set of 20 Semmes-Weinstein monofilaments was used to detect nasal sensitivity for both nasal cavities. The sensitivity threshold was recorded as the minimum monofilament size with which patients could detect at least two of three stimuli.

RESULTS

When compared to the control group (group B), subjects in group A required a significantly (p < 0.05) higher stimulus to trigger a touch response in the monofilament test, for both the inferior (195.1 ± 0.39 mg vs 67.7 ± 0.19 mg) and middle turbinate (108.7 ± 0.23 mg vs 67.7 ± 0.19 mg).

Beneficial effects of chelidonic acid on a model of allergic rhinitis

Chelidonic acid (CA) is known as an inhibitor of the rat brain glutamate decarboxylase. However, the pharmacological effects of CA in allergic reactions have not yet been defined. Here, we show the effects and the mechanism of CA in the ovalbumin (OVA)-sensitized allergic rhinitis (AR) model. CA significantly decreased the number of nasal/ear rubs and increment of IgE levels in the AR mice. The level of interferon-γ was enhanced while the level of IL-4 was reduced on the spleen tissue of the CA-administered AR mice. Expressions of IL-1β and cyclooxygenase-2 were inhibited by CA administration in the nasal mucosa tissues. Infiltration of eosinophils and mast cells was decreased in the CA-administered AR mice. Furthermore, CA decreased the caspase-1 activity in the same nasal mucosa tissue and human mast cell line, HMC-1. Our results indicate that CA may attenuate allergic reaction by inhibition of caspase-1 activity.

Increased Spontaneous Ex Vivo Apoptosis and Subset Alterations in Peripheral Blood T Cells from Patients with Multiple Sclerosis

In order to characterize the immunophenotype and the lymphocyte apoptosis in multiple sclerosis (MS) patients, the peripheral blood lymphocytes of 46 MS patients and 12 healthy volunteers were studied by flow cytometry. Immunophenotypic alterations included significant increases in T CD4+ lymphocytes and reductions in the percentages of CD3+ and CD8+ T cells. After 24 h of culture spontaneous apoptosis was increased in almost T lymphocyte subsets from MS patients and it was significantly higher in those patients who had suffered more than two relapses in the two previous years. The incidence of spontaneous apoptosis was not dependent on FasL-Fas interactions and correlated with the percentages of cells positive for active caspases but not with percentages of Fas+ cells. The increased susceptibility to apoptosis of peripheral blood T lymphocytes from MS patients is difficult to reconcile with the previously proposed role of a defective lymphocyte apoptosis in the pathophysiology of MS.