The expression of osteopontin and its association with Clara cell 10 kDa protein in allergic rhinitis

SCGB1C1 Plays a Critical Role in Suppression of Allergic Airway Inflammation through the Induction of Regulatory T Cell Expansion

The nanosized vesicles secreted from various cell types into the surrounding extracellular space are called extracellular vesicles (EVs). Although mesenchymal stem cell-derived EVs are known to have immunomodulatory effects in asthmatic mice, the role of identified pulmonary genes in the suppression of allergic airway inflammation remains to be elucidated. Moreover, the major genes responsible for immune regulation in allergic airway diseases have not been well documented. This study aims to evaluate the immunomodulatory effects of secretoglobin family 1C member 1 (SCGB1C1) on asthmatic mouse models. C57BL/6 mice were sensitized to ovalbumin (OVA) using intraperitoneal injection and were intranasally challenged with OVA. To evaluate the effect of SCGB1C1 on allergic airway inflammation, 5 μg/50 μL of SCGB1C1 was administrated intranasally before an OVA challenge. We evaluated airway hyperresponsiveness (AHR), total inflammatory cells, eosinophils in the bronchoalveolar lavage fluid (BALF), lung histology, serum immunoglobulin (Ig), the cytokine profiles of BALF and lung-draining lymph nodes (LLN), and the T cell populations in LLNs. The intranasal administration of SCGB1C1 significantly inhibited AHR, the presence of eosinophils in BALF, eosinophilic inflammation, goblet cell hyperplasia in the lung, and serum total and allergen-specific IgE. SCGB1C1 treatment significantly decreased the expression of interleukin (IL)-5 in the BALF and IL-4 in the LLN, but significantly increased the expression of IL-10 and transforming growth factor (TGF)-β in the BALF. Furthermore, SCGB1C1 treatment notably increased the populations of CD4+CD25+Foxp3+ regulatory T cells (Tregs) in asthmatic mice. The intranasal administration of SCGB1C1 provides a significant reduction in allergic airway inflammation and improvement of lung function through the induction of Treg expansion. Therefore, SCGB1C1 may be the major regulator responsible for suppressing allergic airway inflammation.

Anti-Allergic and Anti-inflammatory Effects of Bakuchiol on Ovalbumin-Induced Allergic Rhinitis in Mice

Allergic rhinitis (AR) is a prevalent inflammatory disease primarily affecting the nasal mucosa and is caused by allergies. The common symptoms of AR include rhinorrhea, sneezing, itchy nose, congestion, teary eyes, and nasal rubbings. The present study assessed the beneficial properties of bakuchiol on OVA-induced AR in mice via the regulation of inflammatory responses. AR was induced by injecting (i.p.) OVA (50 µg) and aluminum hydroxide (1 mg) into mice at various time intervals. The bakuchiol treatment was done at dosages of 10 and 20 mg/kg with dexamethasone (2.5 mg/kg) as a positive control. The body weight and nasal symptoms were measured on the day of the last OVA challenge. For in vitro tests, mouse splenocytes were isolated, sensitized with 20 µL OVA, and then treated with 10 µM bakuchiol. The levels of pro-inflammatory cytokines, immunoglobulins, histamine, leukotriene C4 (LTC-4), and prostaglandin D2 (PGD2) were assayed using the corresponding assay kits. The assay kits were also used to analyze the status of oxidative stress markers. The Th1/Th2 cell proportion was assessed using flow cytometry. The bakuchiol (10 and 20 mg/kg) treatment reduced the nasal symptoms in AR mice. Bakuchiol decreased the levels of IL-4, IL-5, IL-13, Igs (IgE and IgG1), histamine, IL-10, IL-33, and TNF-α in AR mice. Bakuchiol also reduced PGDA and LTC-4 levels in the NLF of AR mice. The ROS and MDA levels were decreased, whereas boosted SOD activity was observed in the bakuchiol-treated AR mice. The eosinophil count was decreased in the nasal tissues of bakuchiol-treated AR mice. Bakuchiol also influenced the Th1 and Th2 cell proportions in AR mice. The present findings suggest that bakuchiol is effective against OVA-mediated allergic and inflammatory responses in AR mice through its strong anti-inflammatory properties.

Quercetin-Induced Enhancement of Nasal Epithelial Cells' Ability to Produce Clara Cell 10-kD Protein In Vitro and In Vivo

Background: Quercetin, a polyphenolic flavonoid found in various plants and foods, is known to have antioxidant, antiviral and anticancer effects. Although quercetin is well known to exert anti-inflammatory and anti-allergic effects, the precise mechanisms by which quercetin favorably modifies the clinical status of allergic diseases, such as allergic rhinitis (AR), remain unclear. The present study examined whether quercetin could modulate the production of the endogenous anti-inflammatory molecule, Clara cell 10-kD protein (CC10), in vitro and in vivo. Methods: Human nasal epithelial cells (1 × 10⁵ cells/mL) were stimulated with 20 ng/mL of tumor necrosis factor-alpha (TNF) in the presence of quercetin for 24 h. CC10 levels in culture supernatants were examined by ELISA. Sprague Dawley rats were sensitised with toluene 2,4-diisocyanate (TDI) by intranasal instillation of 10% TDI in ethyl acetate at a volume of 5.0 μL once daily for five days. This sensitisation procedure was repeated after an interval of two days. The rats were treated with different dosages of quercetin once daily for five days starting on the 5th day following the second sensitization. Nasal allergy-like symptoms induced by the bilateral application of 5.0 μL of 10% TDI were assessed by counting sneezing and nasal-rubbing behaviours for 10 min immediately after the TDI nasal challenge. The levels of CC10 in nasal lavage fluids obtained 6 h after TDI nasal challenge were examined using ELISA. Results: The treatment of cells with low doses of quercetin (<2.5 μM) scarcely affected TNF-induced CC10 production from nasal epithelial cells. However, the ability of nasal epithelial cells to produce CC10 after TNF stimulation significantly increased on treatment with quercetin doses (>5.0 μM). The oral administration of quercetin (>25 mg/kg) for five days significantly increased the CC10 content in nasal lavage fluids and attenuated the nasal symptoms induced by the TDI nasal challenge. Conclusions: Quercetin inhibits AR development by increasing the ability of nasal epithelial cells to produce CC10.

The Role and Clinical Relevance of Osteopontin in Allergic Airway Diseases

The airway epithelium is exposed to numerous external irritants including infectious agents, environmental allergens, and atmospheric pollutants, releasing epithelial cytokines including thymic stromal lymphopoietin (TSLP), IL-33, and IL-25 and initiating downstream type 2 (IL-4, IL-13, and IL-5) and IgE-driven pathways. These pathways trigger the initiation and progression of allergic airway diseases, including chronic rhinosinusitis with nasal polyps (CRSwNP), allergic rhinitis (AR), and allergic asthma. However, the use of biological agents that target downstream cytokines, such as IL-5, IL-4, and IL-13 receptors and IgE, might not be sufficient to manage some patients successfully. Instead of blocking downstream cytokines, targeting upstream epithelial cytokines has been proposed to address the complex immunologic networks associated with allergic airway diseases. Osteopontin (OPN), an extracellular matrix glyco-phosphoprotein, is a key mediator involved in Th1-related diseases, including systemic lupus erythematosus, multiple sclerosis, inflammatory bowel disease, and rheumatoid arthritis. Emerging evidence, including ours, indicates that epithelial-cell-derived OPN also plays an essential role in Th2-skewed airway diseases, including CRSwNP, AR, and allergic asthma involving the Th17 response. Therefore, we reviewed the current knowledge of epithelial-cell-derived OPN in the pathogenesis of three type-2-biased airway diseases and provided a direction for its future investigation and clinical relevance.

Club Cell Secretory Protein in Lung Disease: Emerging Concepts and Potential Therapeutics

Club cell secretory protein (CCSP), also known as secretoglobin 1A1 (gene name SCGB1A1), is one of the most abundant proteins in the lung, primarily produced by club cells of the distal airway epithelium. At baseline, CCSP is found in large concentrations in lung fluid specimens and can also be detected in the blood and urine. Obstructive lung diseases are generally associated with reduced CCSP levels, thought to be due to decreased CCSP production or club cell depletion. Conversely, several restrictive lung diseases have been found to have increased CCSP levels both in the lung and in the circulation, likely related to club cell dysregulation as well as increasedlung permeability. Recent studies demonstrate multiple mechanisms by which CCSP dampens acute and chronic lung inflammation. Given these anti-inflammatory effects, CCSP represents a novel potential therapeutic modality in lung disease.

Elevated serum osteopontin levels in patients with severe cutaneous adverse drug reactions

Osteopontin (OPN) was initially described as a protein involved in bone metabolism, but the roles played by OPN in the immune system and allergic reactions have attracted increasing attention. Here, we clarify the OPN-related dynamics of severe cutaneous adverse drug reactions, and assess whether the OPN level has utility for classifying such reactions and serving as a biomarker of severity. Serum OPN levels in patients with drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms (DIHS/DRESS), Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) and erythema multiforme-type drug reaction (EM-DR) were quantified by ELISA. The OPN sources were analyzed by dual immunofluorescence assay of DIHS, SJS/TEN and EM-DR biopsy specimens. The serum OPN levels of DIHS/DRESS patients (489.1 ± 37.0 ng/mL) and SJS/TEN patients (508.5 ± 47.8 ng/mL) were significantly higher compared with controls (314.4 ± 14.3 ng/mL; p < 0.001). After treatment, the serum OPN level of DIHS/DRESS patients decreased to that of controls. In addition, OPN levels in DIHS/DRESS patients and SJS/TEN patients were higher than in patients with EM-DR (Mann-Whitney U test, p < 0.05). However, when the Kruskal-Wallis test was used to compare the OPN levels among the three groups of patients, the difference was not significant (p = 0.055). Dual immunofluorescence assay revealed that T lymphocytes and macrophages were the main OPN sources in DIHS, SJS/TEN and EM-DR patients. These data suggest that the OPN level can be used to evaluate the severity of inflammation in patients experiencing drug reactions.

Nonylphenol exacerbates ovalbumin-induced allergic rhinitis via the TSLP-TSLPR/IL-7R pathway and JAK1/2-STAT3 signaling in a mouse model

Nonylphenol (NP) can be widely used as a plasticizer, surfactant, antioxidant, textile printing, dyeing additive, and pesticide emulsifier. Animal studies have shown that NP aggravates ovalbumin (OVA)-induced allergic rhinitis (AR); however, the exact mechanism underlying its action has not yet been detailed. This study aimed to explore the aggravation of the AR inflammatory response following NP exposure and its possible mechanism. The AR mouse model was constructed using OVA. Under NP exposure, allergic nasal symptoms were observed, eosinophil infiltration was assessed by Sirius red staining, and the levels of IL-4, IL-5, and IL-13 in nasal mucosa samples were detected using cytometric bead array. The mRNA levels of OX40/OX40L and GATA3 in nasal mucosa were detected by qPCR, and the expression levels of the TSLP and JAK1/2-STAT3 signaling pathway components were also identified. Our results suggest that NP exposure exacerbated allergic nasal symptoms and that eosinophils accumulated in nasal mucosa after OVA challenge. The levels of the typical T helper 2 cytokines, as well as the mRNA levels of OX40/OX40L and GATA3, were elevated in the nasal mucosa of OVA-challenged mice exposed to NP. In addition, NP exposure elevated the TSLP, TSLPR, IL-7R, p-JAK1, p-JAK2, and p-STAT3 levels in the nasal mucosa after OVA stimulation. Overall, the present study suggests NP can exacerbate OVA-induced AR inflammatory responses; furthermore, this aggravating effect of NP may be related to the TSLP-TSLPR/IL-7R and JAK1/2-STAT3 signaling pathways.

Secretoglobins in the big picture of immunoregulation in airway diseases

The proteins of the secretoglobin (SCGB) family are expressed by secretory tissues of barrier organs. They are embedded in immunoregulatory and anti-inflammatory processes of airway diseases. This review particularly illustrates the immune regulation of SCGBs by cytokines and their implication in the pathophysiology of airway diseases. The biology of SCGBs is a complex topic of increasing importance, as they are highly abundant in the respiratory tract and can also be detected in malignant tissues and as elements of immune control. In addition, SCGBs react to cytokines, they are embedded in Th1 and Th2 immune responses, and they are expressed in a manner dependent on cell maturation. The big picture of the SCGB family identifies these factors as critical elements of innate immune control at the epithelial barriers and highlights their potential for diagnostic assessment of epithelial activity. Some members of the SCGB family have so far only been superficially examined, but have high potential for translational research.

Health effects of exposure to chlorination by-products in swimming pools

Concerns have been raised regarding the potential negative effects on human health of water disinfectants used in swimming pools. Among the disinfection options, the approaches using chlorine-based products have been typically preferred. Chlorine readily reacts with natural organic matter that are introduced in the water mainly through the bathers, leading to the formation of potentially harmful chlorination by-products (CBPs). The formation of CBPs is of particular concern since some have been epidemiologically associated with the development of various clinical manifestations. The higher the concentration of volatile CBPs in the water, the higher their concentration in the air above the pool, and different routes of exposure to chemicals in swimming pools (water ingestion, skin absorption, and inhalation) contribute to the individual exposome. Some CBPs may affect the respiratory and skin health of those who stay indoor for long periods, such as swimming instructors, pool staff, and competitive swimmers. Whether those who use chlorinated pools as customers, particularly children, may also be affected has been a matter of debate. In this article, we discuss the current evidence regarding the health effects of both acute and chronic exposures in different populations (work-related exposures, intensive sports, and recreational attendance) and identify the main recommendations and unmet needs for research in this area.

Roles of Clara cell 10-kD protein and type 2 innate lymphoid cells in allergic rhinitis

This study examined the potential roles of CC10 (Clara cell 10-kD protein) and ILC2s (type 2 innate lymphoid cells) in allergic rhinitis (AR). After ovalbumin was used to construct the AR model, microarray analysis was performed to reveal the key differentially expressed genes. The phenotypic changes of nasal mucosa were examined by H&E staining. Western blot analysis, qRT-PCR, ELISA and immunohistochemistry were performed to identify the levels of cytokines. The lineage markers (CD127 and CD117) of ILC2s were detected using immunofluorescence. The microarray analysis and qRT-PCR results showed that CC10 overexpression inhibited the expression of A20, BAFF, and IL-4 R in vivo. Also, CC10 overexpression was found to ameliorate the damage of nasal mucosa in AR mice. Investigations revealed that the ILC2s were activated in AR mice and AR patients with high levels of IgE, IgG1, IL-4, IL-5, IL-13, IL-25, and IL-33. Moreover, CD127+ was found to activate ILC2s. However, CC10 overexpression suppressed the activation of ILC2s. In conclusion, this research suggested that CC10 could suppress the activation of ILC2s to attenuate the damage of nasal mucosa and that CD127+ may be a biomarker of the activation of ILC2s in AR mice and AR patients.

Anti-allergic and anti-inflammatory effects of resveratrol via inhibiting TXNIP-oxidative stress pathway in a mouse model of allergic rhinitis

Background

Allergic rhinitis (AR) is a type I hypersensitivity mediated by IgE in the nose. Thioredoxin-interacting protein (TXNIP) plays a pivotal role in the process of producing reactive oxygen species (ROS). Resveratrol is a TXNIP inhibitor. Nonetheless, its role and mechanism in AR are still undetermined. The present study aimed to explore the effect and mechanism of resveratrol on an ovalbumin (OVA) induced mouse model of AR.

Methods

AR murine model was established using OVA and administrated intranasally with resveratrol or N-acetylcysteine (NAC). Hematoxylin and eosin (HE) stain was used for evaluating eosinophils. Immunohistochemistry (IHC) staining and real-time PCR were employed to evaluate immunolabeling and mRNA expression of TXNIP in nasal mucosas of mice. Malondialdehyde (MDA) level and superoxide dismutase (SOD) activity in nasal tissue homogenates were measured using MDA and SOD Assay Kit. Concentrations of OVA-specific IgE and histamines in serum, and OVA-specific IgE, PGD2, LTC4, ECP, IL-4, IL-5, IL-6, IL-33 and TNF-α in nasal lavage fluid (NLF) were assayed by ELISA. In vitro studies, western blotting, real-time PCR, ELISA, ROS detecting dye DCFH-DA, MDA, and SOD Assay Kit were performed to evaluate the effects and mechanisms of OVA, resveratrol or NAC on spleen mononuclear cells.

Results

We found significant alternations of sneezing, nasal rubbing, inflammatory cytokines, eosinophil numbers, TXNIP, MDA, and SOD levels in resveratrol or NAC treated mice compared with untreated AR mice. In cultured spleen mononuclear cells, TXNIP, MDA, SOD, ROS and inflammatory cytokines levels were altered by OVA but reversed by resveratrol or NAC.

Conclusions

Resveratrol could effectively alleviate murine AR by inhibiting TXNIP-oxidative stress pathway.

Ameliorative effect of selective NLRP3 inflammasome inhibitor MCC950 in an ovalbumin-induced allergic rhinitis murine model

Allergic rhinitis (AR) is a complex IgE-mediated nasal allergic and inflammatory disease. Nucleotide-binding domain (NOD)-like receptor protein 3 (NLRP3) is essential in the process of allergic and inflammatory responses. MCC950 is a selective NLRP3 inhibitor. However, its role and mechanism in AR remains undetermined. The present study aimed to explore the effect and mechanism of MCC950 on an ovalbumin (OVA) induced mouse model of AR. The AR BALB/c mice were constructed using OVA and administrated intranasally with MCC950. Concentrations of OVA-specific IgE, histamines and leukotrienes C4 (LTC4) in serum, and OVA-specific IgE, ECP, IFN-γ, IL-4, IL-5, IL-13, IL-1β and IL-18 in nasal lavage fluid (NLF) were assayed by enzyme-linked immunosorbent assay (ELISA). Inflammatory cells were counted in NLF. HE and PAS staing were used for evaluating eosinophils and goblet cells. Immunohistochemistry (IHC) staining were employed to evaluate immunolabeling of NLRP3, Caspase-1, ASC, IL-1β and IL-18 in nasal mucosas of mice. Real-time PCR was conducted to assay NLRP3, Caspase-1, ASC, IL-1β and IL-18 mRNA levels. In vitro studies, western blotting, real-time PCR and ELISA were performed to evaluate the effects and mechanisms of OVA and NLRP3 inhibitor MCC950 on spleen mononuclear cells. We found significant downregulation of sneezing, nasal rubbing, inflammatory cytokines, inflammatory cells and NLRP3, Caspase-1, ASC, IL-1β and IL-18 expression in MCC950 treated mice compared with untreated AR mice. In spleen mononuclear cells culture and stimulation experiment, NLRP3, Caspase-1, ASC, IL-1β and IL-18 levels were upregulated by OVA but inhibited by MCC950. In conclusion, MCC950 could effectively exert its ameliorative effect in murine AR by inhibiting NLRP3 and leads to reduction of Caspase-1, ASC, IL-1β and IL-18, resulting in the attenuation of the allergic and inflammatory responses.

Ethanol extract of Dryopteris crassirhizoma alleviates allergic inflammation via inhibition of Th2 response and mast cell activation in a murine model of allergic rhinitis

ETHNOPHARMACOLOGICAL RELEVANCE

Dryopteris crassirhizoma (DC) is used as a traditional herbal remedy to treat various diseases, the tapeworm infection, common cold, and cancer in Korea, Japan, and China. DC also has the antioxidant anti-inflammatory and antibacterial activities. However, the anti-allergic inflammatory effect of DC and some of its mechanisms in allergic rhinitis model are unknown well.

AIM OF THIS STUDY

The purpose of this study is to investigate the anti-allergic inflammatory effect of DC on the allergic rhinitis model, mast cell activation and histamine release.

MATERIALS AND METHODS

Allergic rhinitis was induced in BALB/c mice by sensitization and challenge with ovalbumin (OVA). Different concentration of DC and dexamethasone was administrated by oral gavage on 1 h before the OVA challenge. Mice of the control group were treated with saline only. Then mice were evaluated for the presence of nasal mucosa inflammation, the production of allergen-specific cytokine response and the histology of nasal mucosa.

RESULTS

DC significantly ameliorated the nasal symptoms and the inflammation of nasal mucosa. DC also reduced the infiltration of eosinophils and mast cells in these tissues and the release of histamine in blood. Meanwhile, DC evidently inhibited the overproduction of Th2 cytokines and increased the Th1 and Treg cytokines in nasal lavage fluid by OVA. DC also reduced the levels of OVA-specific IgE, IgG1 and IgG2a in blood.

CONCLUSIONS

This study suggests that DC has a significant anti-allergic inflammatory effect in the nasal cavity. DC may have the therapeutic effect of allergic rhinitis.

Clara Cell 10 kDa Protein Alleviates Murine Hepatitis Virus Strain 3-Induced Fulminant Hepatitis by Inhibiting Fibrinogen-Like Protein 2 Expression

Background: Fulminant hepatitis (FH) is a serious threat to human life, accompanied by massive and rapid necroinflammation. Kupffer cells, the major immune cell population involved in innate immune responses, are considered to be central for FH. Fibrinogen-like protein 2 (Fgl2) is a pro-coagulant protein that is substantially induced in macrophages upon viral infection, and Fgl2 depletion represses murine hepatitis virus strain 3 (MHV-3) infection. Clara cell 10 kDa (CC10) protein is a secretory protein with anti-inflammatory properties in allergic rhinitis and asthma. However, its mechanisms of action and pathogenic roles in other disease are still unclear. In this study, we aimed to determine the role of CC10 in FH and the regulation of Fgl2 by CC10.

Methods: A mouse FH model was established by peritoneal injection of MHV-3. The mice received CC10 protein through tail vein injection before viral infection. Survival rate, liver function, liver histology, fibrin deposition, and necrosis were examined. The regulatory effect of CC10 on Fgl2 expression was investigated using THP-1 cells and mouse peritoneal macrophages in vitro.

Results: In the mouse FH model induced by MHV-3, the survival rate increased from 0 to 12.5% in the CC10 group compared to that in the saline-only control group. Meanwhile, the levels of ALT and AST in serum were significantly decreased and liver damage was reduced. Furthermore, hepatic Fgl2, TNF-α, and IL-1β expression was obviously downregulated together with fibrin deposition, and hepatocyte apoptosis was reduced after administration of CC10 protein. In vitro, CC10 was found to significantly inhibit the expression of Fgl2 in IFN-γ-treated THP-1 cells and MHV-3-infected mouse peritoneal macrophages by western blot and real-time PCR. However, there was no direct interaction between CC10 and Fgl2 as shown by co-immunoprecipitation. Microarray investigations suggested that HMG-box transcription factor 1 (HBP1) was significantly low in CC10-treated and IFN-γ-primed THP-1 cells. HBP1-siRNA treatment abrogated the inhibitory effect of CC10 on Fgl2 expression in Human Umbilical Vein Endothelial cells (HUVECs).

Conclusion:CC10 protects against MHV-3-induced FH via suppression of Fgl2 expression in macrophages. Such effects may be mediated by the transcription factor HBP1.

Circulating Clusterin and Osteopontin Levels in Asthma and Asthmatic Pregnancy

Asthma in pregnancy poses a risk of adverse outcomes. Osteopontin and clusterin emerged as asthma biomarkers; however, their circulating levels during pregnancy are unknown yet. This cross-sectional study investigated peripheral osteopontin and clusterin levels and their relationship to disease control in 26 asthmatic pregnant (AP), 22 asthmatic nonpregnant (ANP), and 25 healthy pregnant (HP) women and 12 healthy controls (HNP). Osteopontin levels of ANP and HNP were similar (2.142 [1.483-2.701] versus 2.075 [1.680-2.331] ng/mL, p = 0.7331). Pregnancy caused a marked elevation in both healthy (HP: 3.037 [2.439-4.015] ng/ml, p = 0.003 versus HNP) and asthmatic (AP: 2.693 [1.581-3.620] ng/ml) patients; thus the pregnant groups did not differ (p = 0.3541). Circulating clusterin levels were comparable in ANP and HNP (109.2 [95.59-116.3] versus 108.8 [97.94-115.3] µg/mL, p = 0.8730) and the level was lower in HP (98.80 [84.26-105.5] µg/mL, p = 0.0344 versus HNP). In contrast, the level was higher in AP (111.7 [98.84-125.6] µg/mL, p = 0.0091 versus HP). In ANP, a positive correlation of PEF (r = 0.3405; p = 0.0221) and a negative correlation of R_aw (r = -0.3723; p = 0.0128) to clusterin level were detected. Circulating osteopontin level increases in pregnancy regardless of concomitant well-controlled asthma, indicating its gestational role. Clusterin level decreases in healthy but not in asthmatic pregnancy and correlates directly with lung function.

MicroRNA let-7a up-regulates OPN expression in a mouse model of allergic rhinitis

Objective:

To investigate the effect of microRNA let-7a on OPN expression in a mouse model of allergic rhinitis.

Methods:

Thirty-two mature female C57BL/6 mice were randomly divided into four groups, with eight mice in each group: microRNA let-7a, microRNA control, OVA and phosphate-buffered saline groups. The microRNA let-7a, microRNA control and OVA groups were sensitised with OVA to establish a mouse model of allergic rhinitis. Nose-scratching events were counted. Nasal mucosa was used to evaluate histological changes of goblet cell hyperplasia. Interleukins 5 and 13 were detected. Interferon-γ levels in the nasal lavage fluid were assayed with enzyme-linked immunosorbent assay. OPN expression was estimated with polymerase chain reaction.

Results:

Compared with microRNA control mice, microRNA let-7a treated mice had a significantly increased number of nose-scratching events, nasal mucosal eosinophilia and goblet cell hyperplasia (p < 0.05), and significantly higher interleukins 5 and 13 in nasal mucosa (p < 0.05), but there was no significant difference in interferon-γ (p > 0.05). In addition, microRNA let-7a treated mice had significantly enhanced OPN expression in nasal mucosa (p < 0.05).

Conclusion:

MicroRNA let-7a can promote allergic rhinitis development partly by regulating OPN expression.

Pharmacokinetics and Differential Regulation of Cytochrome P450 Enzymes in Type 1 Allergic Mice

Type 1 allergic diseases are characterized by elevated production of specific immunoglobulin E (IgE) for each antigen and have become a significant health problem worldwide. This study investigated the effect of IgE-mediated allergy on drug pharmacokinetics. To further understand differential suppression of hepatic cytochrome P450 (P450) activity, we examined the inhibitory effect of nitric oxide (NO), a marker of allergic conditions. Seven days after primary sensitization (PS7) or secondary sensitization (SS7), hepatic CYP1A2, CYP2C, CYP2E1, and CYP3A activities were decreased to 45%-75% of the corresponding control; however, CYP2D activity was not downregulated. PS7 and SS7 did not change the expression levels of five P450 proteins. Disappearance of CYP1A2 and CYP2D substrates from the plasma was not significantly different between allergic mice and control mice. In contrast, the area under the curve of a CYP1A2-mediated metabolite in PS7 and SS7 mice was reduced by 50% of control values. Total clearances of a CYP2E1 substrate in PS7 and SS7 mice were significantly decreased to 70% and 50% respectively, of the control without altering plasma protein binding. Hepatic amounts of CYP1A2 and CYP2E1 substrates were enhanced by allergic induction, being responsible for each downregulated activity. NO scavenger treatment completely improved the downregulated P450 activities. Therefore, our data suggest that the onset of IgE-mediated allergy alters the pharmacokinetics of major P450-metabolic capacity-limited drugs except for CYP2D drugs. NO is highly expected to participate in regulatory mechanisms of the four P450 isoforms.

Decreased epithelial and plasma miR-181b-5p expression associates with airway eosinophilic inflammation in asthma

BACKGROUND

Airway eosinophilic inflammation is a pivotal feature of asthma. Epithelial cells play critical roles in airway eosinophilia. We hypothesized that epithelial microRNAs (miRNAs) are involved in airway eosinophilia.

OBJECTIVE

This study investigated the associations between epithelial and plasma miR-181b-5p and airway eosinophilic inflammation, and the possible mechanism by which miR-181b-5p participates in eosinophilic inflammation.

METHODS

Epithelial miRNAs expression was profiled by miRNA array in eight subjects with asthma and four healthy controls. Epithelial miR-181b-5p expression was confirmed by quantitative PCR in the subjects for array experiment and another cohort including 21 subjects with asthma and 10 controls. Plasma miR-181b-5p was determined by quantitative PCR in 72 subjects with asthma and 35 controls. Correlation assays between epithelial and plasma miR-181b-5p expression and airway eosinophilia were performed. The target of miR-181b-5p, SPP1, was predicted by online algorithms and verified in BEAS-2B cells. The role of miR-181b-5p in epithelial proinflammatory cytokine expression was examined in an in vitro system.

RESULTS

Epithelial miR-181b-5p expression was decreased in subjects with asthma. Epithelial miR-181b-5p levels were inversely correlated with sputum and bronchial submucosal eosinophilia. Plasma miR-181b-5p was decreased and correlated with epithelial miR-181b-5p in subjects with asthma. There was a strong inverse correlation between plasma miR-181b-5p and airway eosinophilia in subjects with asthma. Plasma miR-181b-5p was increased after inhaled corticosteroids treatment. We verified that SPP1 is a target of miR-181b-5p. In human bronchial epithelial cells, miR-181b-5p regulated IL-13-induced IL-1β and CCL11 expression by targeting SPP1. Dexamethasone restored IL-13-induced miR-181b-5p down-regulation and suppressed IL-13-induced SPP1, IL-1β and CCL11 expression.

CONCLUSIONS AND CLINICAL RELEVANCE

Epithelial and plasma miR-181b-5p are potential biomarkers for airway eosinophilia in asthma. MiR-181b-5p may participate in eosinophilic airway inflammation by regulating proinflammatory cytokines expression via targeting SPP1.

Correlation between Serum Osteopontin and miR-181a Levels in Allergic Rhinitis Children

Background. Osteopontin (OPN) has been proved to be associated with allergic airway inflammation. However, the roles of OPN and its regulation in childhood allergic rhinitis (AR) are poorly understood. Objective. This study aims to evaluate the expression of OPN and miR-181a in children with AR and their association with Th1/Th2 immune response. Methods. Children who suffered from AR were included along with control subjects. Serum was collected to examine the level of OPN and Th1/Th2 cytokines by enzyme-linked immunosorbent assay (ELISA) and the level of miR-181a by quantitative polymerase chain reaction (qPCR). Results. Children with AR had significantly higher serum levels of OPN and lower serum levels of miR-181a than healthy controls. Furthermore, serum levels of OPN were positively correlated with Th2 cytokine and negatively correlated with Th1 cytokine. On the contrary, miR-181a level had a negative correlation with IL-4/IL-5 and positive correlation with IFN-γ/IL-12. More importantly, there was also significant negative correlation between OPN and miR-181a. Conclusion. The OPN protein and miR-181a levels may serve as predictors of disease severity in childhood AR and appear to be promising targets for modulating AR.

Osteopontin promotes dendritic cell maturation and function in response to HBV antigens

Purpose

Dendritic cells (DCs) play critical roles in promoting innate and adaptive immunity in microbial infection. Functional impairment of DCs may mediate the suppression of viral-specific T-cell immune response in chronic hepatitis B (CHB) patients. Osteopontin (OPN) is involved in several liver diseases and infectious diseases. However, whether OPN affects DC function in hepatitis B virus (HBV) infection is unknown.

Methods

Twenty CHB patients and 20 healthy volunteers were recruited. OPN secreted by DCs was compared. Peripheral blood mononuclear cells cultured with OPN antibody were examined to study the costimulatory molecular expression and interleukin (IL)-12 production of DCs after HBV antigenic stimulation. OPN-deficient mice were used to investigate the influence of OPN on DC maturation and function after HBV antigenic stimulation in vitro and in vivo. Exogenous OPN was administrated to further verify the functioning of DCs from CHB patients upon HBV antigenic stimulation.

Results

We found that OPN production of DCs from CHB patients was significantly lower than those from healthy volunteers. The absence of OPN impaired IL-12 production and costimulatory molecular expression of DCs upon stimulation with HBV antigens. Defective DC function led to reduced activation of Th1 response to HBV antigens. In addition, OPN deficiency in DCs reduced the HBV antigen-induced inflammatory response in the liver of mice. Importantly, OPN administration significantly promoted the maturation of DCs from CHB patients in vitro.

Conclusion

These findings suggested that OPN could improve the maturation and functioning of DCs in the immune response to HBV antigens, which might be useful to further improve the effect of DC vaccine.

Increased osteopontin levels in children undergoing venom immunotherapy may serve as a marker of clinical efficacy

BACKGROUND

Venom immunotherapy (VIT) has its effect by modulating various mediators resulting in immune tolerance. The aim of this study was to measure changes in plasma osteopontin (OPN) and serum basal tryptase (sBT) levels over the course of 1 year of VIT in children with venom allergy.

METHODS

Children who suffered from a large local reaction (LLR) or a systemic reaction (SR) after insect stings were included along with control subjects. Measurements were performed before the initiation of VIT and 6 and 12 months after it had been started.

RESULTS

A total of 58 children (24 with SR, 18 with LLR and 16 control subjects) with a median age of 9.5 years (range 6.7-12.8) were enrolled. The plasma OPN levels of patients with LLR [median 1,477 ng/ml, interquartile range (IQR) 1,123-1,772] were significantly higher than patients with SR (882 ng/ml, 579-1,086; p < 0.001) and healthy control subjects (1,015 ng/ml, 815-1,203; p = 0.002). A significant increase in plasma OPN levels in children was determined after the 1-year VIT. The sBT levels of children with SR (4.1 ng/ml, 3.6-5.8) were significantly higher than children with LLR (3.1 ng/ml, 2.5-4.0) and control subjects (3.0 ng/ml, 2.9-3.8; p = 0.001). There was no significant change in the sBT levels of the patients after the 1-year VIT.

CONCLUSIONS

The results of our study showed higher baseline levels of OPN in children with LLR compared to control subjects and children with SR. In children with SR, OPN levels were increased after the 1-year VIT. Our results may suggest a possible association between OPN and successful VIT in children.

No effect of ablation of surfactant protein-D on acute cerebral infarction in mice

Background

Crosstalk between the immune system in the brain and the periphery may contribute to the long-term outcome both in experimental and clinical stroke. Although, the immune defense collectin surfactant protein-D (SP-D) is best known for its role in pulmonary innate immunity, SP-D is also known to be involved in extrapulmonary modulation of inflammation in mice. We investigated whether SP-D affected cerebral ischemic infarction and ischemia-induced inflammatory responses in mice.

Methods

The effect of SP-D was studied by comparing the size of ischemic infarction and the inflammatory and astroglial responses in SP-D knock out (KO) and wild type (WT) mice subjected to permanent middle cerebral artery occlusion. SP-D mRNA production was assessed in isolated cerebral arteries and in the whole brain by PCR, and SP-D protein in normal appearing and ischemic human brain by immunohistochemistry. Changes in plasma SP-D and TNF were assessed by ELISA and proximity ligation assay, respectively.

Results

Infarct volumetric analysis showed that ablation of SP-D had no effect on ischemic infarction one and five days after induction of ischemia. Further, ablation of SP-D had no effect on the ischemia-induced increase in TNF mRNA production one day after induction of ischemia; however the TNF response to the ischemic insult was affected at five days. SP-D mRNA was not detected in parenchymal brain cells in either naïve mice or in mice subjected to focal cerebral ischemia. However, SP-D mRNA was detected in middle cerebral artery cells in WT mice and SP-D protein in vascular cells both in normal appearing and ischemic human brain tissue. Measurements of the levels of SP-D and TNF in plasma in mice suggested that levels were unaffected by the ischemic insult. Microglial-leukocyte and astroglial responses were comparable in SP-D KO and WT mice.

Conclusions

SP-D synthesis in middle cerebral artery cells is consistent with SP-D conceivably leaking into the infarcted area and affecting local cytokine production. However, there was no SP-D synthesis in parenchymal brain cells and ablation of SP-D had no effect on ischemic cerebral infarction.

Elevated level of serum osteopontin in school-age children with asthma

BACKGROUND

The role of osteopontin (OPN) has not been elucidated in childhood asthma.

OBJECTIVE

Our purpose was to investigate whether OPN levels change due to allergic inflammation in pre-school and school-age children.

METHODS

In this prospective, cross-sectional study, 42 healthy children and a total of 51 children with asthma were recruited. OPN levels and its association with clinical and laboratory parameters were investigated in the study population. The asthma group were divided into two groups with respect to age, ≤ 5-years (n = 23) and >5-years (n = 28), and labelled Asthma Group 1 and Asthma Group 2, respectively. OPN levels were compared between subgroups.

RESULTS

Serum OPN levels were significantly higher in the asthma group when compared to the control group (p = 0.004). OPN levels were similar in Asthma Group 1 and control groups, whereas it was found to be higher in Asthma Group 2 (p>0.025, p = 0.001, respectively). In the >5-years age asthmatic group, OPN levels of the patients with allergic rhinitis (n = 15) were higher than those of the patients (n=13) without allergic rhinitis (p = 0.021).

CONCLUSION

The study underscores the relationship between childhood asthma and OPN as the first study in the literature. In this study we found that OPN, which plays a role in Th2 mediated inflammation, may also play a role in childhood asthma. The fact that OPN levels do not increase in preschool-age children with asthma might be due to the transient wheezing in this group.

Exogenous interleukin-10 alleviates allergic inflammation but inhibits local interleukin-10 expression in a mouse allergic rhinitis model

Background

Interleukin-10 (IL-10) has an important anti-inflammatory and immunoregulatory function, and its expression is negatively correlated with the development and severity of allergic rhinitis (AR). However, the in vivo effects of exogenous IL-10 on AR have not been studied and the mechanisms underlying the effects of IL-10 have not been fully understood. Here, we investigated the effects of intranasal administration of recombinant mouse (rm) IL-10 on the expression of Th responses and local IL-10 in a mouse model of AR induced by ovalbumin.

Results

Administration of rmIL-10 during challenge significantly reduced the number of eosinophils and mast cells, as well as Type 2 helper T (Th2) and Th17 cell related cytokine and transcription factor levels in the nasal mucosa and nasal lavage fluid in AR mice. The rmIL-10 treatment significantly inhibited the number of IL-10-positive cells and IL-10 mRNA expression in the nasal mucosa in AR mice.

Conclusion

Our results show that exogenous IL-10 administrated in challenge phase alleviates nasal allergic inflammation in AR mice, most likely by inhibiting Th2 and Th17 responses. It can also inhibit local IL-10 levels in the nasal mucosa. Our findings indicate that IL-10 may have the potential as an inhibitor of AR.

Suppression of osteopontin functions by levocetirizine, a histamine H1 receptor antagonist, in vitro

OBJECTIVES

Osteopontin (OPN), a multifunctional glycoprotein secreted from a wide variety of cells after inflammatory stimulation, is well accepted to contribute to the development of allergic diseases. However, the influence of histamine H1 receptor antagonists (antihistamines) on OPN functions is not well understood. The present study was undertaken to examine the influence of antihistamines on OPN functions in vitro.

METHODS

Human nasal epithelial cells (5 × 10(5) cells) were stimulated with 250 ng/mL OPN in the presence of either desloratadine (DL), fexofenadine (FEX), or levocetirizine (LCT). The levels of OPN, GM-CSF, Eotaxin, and RANTES in 24 h culture supernatants were examined by ELISA. The influence of LCT on mRNA expression and transcription factor activation in cells were also examined by real-time RT-PCR and ELISA, respectively.

KEY FINDINGS

The antihistamines examined significantly suppressed the production of GM-CSF, Eotaxin, and RANTES from cells after OPN stimulation. LCT also exhibited the suppression of mRNA expression for chemokines and transcription factor, NF- κ B and AP-1, activation, which were increased by the stimulation of cells with OPN.

CONCLUSIONS

The suppressive activity of LCT on OPN functions on nasal epithelial cells may be responsible for the attenuating effect of the agent on allergic diseases.

Clara cell 10-kD protein in inflammatory upper airway diseases

PURPOSE OF REVIEW

To discuss the role of Clara cell 10-kD protein (CC10), an anti-inflammatory and immunomodulatory molecule, in inflammatory upper airway diseases, particularly in allergic rhinitis and chronic rhinosinusitis (CRS).

RECENT FINDINGS

CC10 expression is downregulated in allergic rhinitis and CRS. CC10 can inhibit the expression of chitinase 3-like 1 protein and osteopontin in eosinophilic CRS and allergic rhinitis, respectively. CC10 can also suppress osteopontin-induced expression of Th2 and proinflammatory cytokines in airway epithelial cells, and CC10 gene transfection can inhibit NF-κB activity in airway epithelial cells. Proinflammatory and Th2 cytokines can diminish CC10 production, whereas Th1 cytokines and interleukin-10 can promote CC10 production in sinonasal mucosa. Allergen exposure leads to a transdifferentiation of CC10 secreting cells into trefoil factor family 1 secreting cells and/or goblet cells in upper airways, resulting in the diminished expression of CC10.

SUMMARY

Allergen exposure and Th2 milieu can suppress the expression of CC10 in upper airways. CC10 can inhibit Th2-dominated eosinophilic inflammation in upper airways via multiple pathways.

Clara cell 10-kDa protein inhibits T(H)17 responses through modulating dendritic cells in the setting of allergic rhinitis

BACKGROUND

T(H)17 responses have recently been implicated to play a role in allergic airway diseases, but their local expression in the setting of allergic rhinitis (AR) and their regulation in allergic airway diseases remain unclear.

OBJECTIVE

We sought to investigate the regulatory role of Clara cell 10-kDa protein (CC10), an endogenous regulator of airway inflammation, on T(H)17 responses in the setting of AR.

METHODS

Wild-type and homozygous CC10-null mice were used to establish an ovalbumin (OVA)-induced AR model. Human recombinant CC10 was given during sensitization or challenge. T(H)17 responses in human subjects and mice were examined by using flow cytometry, quantitative RT-PCR assay, immunohistochemistry, and ELISA. The direct effect of CC10 on T(H)17 cells and CD11c(+) dendritic cells (DCs) was studied by means of cell culture. Adoptive transfer was used to examine the influence of CC10-conditioned DCs on airway inflammation. The regulatory effect of CC10 on the expression of the CCL20 gene was tested by using the BEAS-2B cell line.

RESULTS

Compared with those of control subjects, T(H)17 responses were enhanced in the nasal mucosa of patients with AR. CC10-null mice with AR showed enhanced T(H)17 responses, and CC10 treatment significantly decreased T(H)17 responses. CC10 had no direct effect on in vitro T(H)17 cell differentiation. CC10 could significantly decrease the expression of OX40 ligand, IL-23, and IL-6 but enhance CD86 and TGF-β expression in DCs. Importantly, CC10 was able to inhibit T(H)17 cell polarization in the presence of OVA-pulsed DCs. CC10 pretreatment inhibited T(H)17 responses elicited by adoptive transfer of OVA-pulsed DCs. Furthermore, CC10 decreased the expression of CCL20 in BEAS-2B cells induced by inflammatory cytokines.

CONCLUSION

T(H)17 responses are enhanced in patients with AR, and CC10 inhibits T(H)17 responses through modulation of the function of DCs.

Mite allergen decreases DC-SIGN expression and modulates human dendritic cell differentiation and function in allergic asthma

House dust mites (HDMs) induce allergic asthma in sensitized individuals, although how HDMs activate immature mucosal dendritic cells (DCs) to render the T helper cell type 2 (Th2)-mediated immune response is unclear. In this study, our results showed a significant calcium-dependent lectin binding of Dermatophagoides pteronyssinus (Der p) extracts to DC-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN), the C-type lectin receptors (CLRs) of DCs. Moreover, monocyte-derived DCs (MDDCs) of Der p-sensitized asthmatics (AS) exhibited decreased expression of DC-SIGN, increased endocytosis, and impaired differentiation of DC precursors. The Der p-induced downregulation of DC-SIGN expression in the differentiation of immature MDDCs may be because of the internalization of Der p-DC-SIGN complex. MDDCs of AS produced more interleukin (IL)-6 and less IL-12p70 cytokines when stimulated with lipopolysaccharide (LPS) or Der p than those of nonallergic controls (NC). In the co-culture experiments, MDDCs pretreated with Der p induced GATA-3 expression and IL-4 cytokine productions in naive CD4(+) T cells. These effects of Der p on the differentiation and function of MDDCs could be partially blocked by anti-DC-SIGN antibodies. In conclusion, our results suggest a critical step of allergen sensitization that involves CLRs in the innate immune response of DCs, which may provide a therapeutic or preventive potential for allergic asthma.

Role of osteopontin, a multifunctional protein, in allergy and asthma

Osteopontin (OPN) is an extracellular matrix protein and immune modulator with a wide range of functions. OPN is recognized as a key cytokine in Th1 immune responses, yet its potential involvement in allergic/asthmatic responses has been investigated only recently. Current data from molecular and cellular studies and studies of OPN-deficient mice provide evidence that OPN plays multiple roles in the regulation of allergic responses, including regulation of IgE response, inflammatory cell migration, and the development of airway fibrosis and angiogenesis. These results suggest that OPN is a pleiotropic cytokine that functions both systemically and locally in tissue mucosa. Notably, OPN is able to exert its effects through different functional domains, and the secreted and intracellular forms of OPN may have distinct functions. Future research to elucidate all aspects of OPN function is needed to ultimately establish its role in the regulation of immune responses and various disease processes, including those critically involved in the development of allergies and asthma.

Osteopontin and allergic disease: pathophysiology and implications for diagnostics and therapy

Osteopontin (OPN) is a phosphoglycoprotein that is expressed by various immune cells in a secreted and intracellular form. It has cytokine, chemotactic and cell signaling functions enhancing Th1 and Th17 immunity and protects against apoptosis. Recent studies found OPN to be modulatory in cell-mediated and immediate-type allergic diseases. In allergic asthma, OPN enhances sensitization but downmodulates Th2-driven IL-4-dominated inflammation. The finding that OPN expression is augmented during specific immunotherapy supports a Th2 suppressive effect of OPN. In Th1-driven delayed-type allergy, such as allergic contact dermatitis, OPN supports dendritic cell migration and IL-12 expression and is secreted by T effector cells and keratinocytes, augmenting Th1-mediated allergy and supporting disease chronification. There are numerous missing links as to how OPN variants modulate allergic inflammation through different OPN receptors. OPN research in allergy is an interesting, rapidly expanding field that has high potential for translational research.

Transdifferentiation of Clara cell 10-kDa protein secreting cells in experimental allergic rhinitis

BACKGROUND

The reasons for the down-regulated Clara cell 10-kDa protein (CC10) expression in allergic rhinitis (AR) are unclear and the airway remodeling in AR has received little attention. This study explores epithelium remodeling and the change of CC10 secreting cells in AR by using a murine model.

METHODS

AR murine models were established by ovalbumin sensitization and challenge. In some mice, dexamethasone was given before each challenge. Histological changes of nasal mucosa were examined by means of hematoxylin and eosin and periodic acid-Schiff staining. CC10 and trefoil factor family (TFF) 1 expression were evaluated by immunohistochemistry.

RESULTS

In AR mice, both in turbinate and in septal mucosa, total cell number and the number of basal cells did not change; however, the number of dome-shaped cells decreased and the number of ciliated and goblet cells increased in turbinate mucosa, and the number of ciliated cells decreased and the number of goblet cells increased in septal mucosa. In turbinate mucosa, the number of CC10(+) cells (mainly dome-shaped cells) decreased whereas the number of TFF1(+) cells (mainly ciliated cells) increased. In septal mucosa, the number of CC10(+) and TFF1(+) cells (mainly ciliated cells) decreased simultaneously. Intermediate phenotypic goblet cells could express CC10 and TFF1. CC10 and TFF1 could be localized in the same cells. Dexamethasone reversed the changes of epithelium significantly.

CONCLUSION

Allergen exposure leads to a possible transdifferentiation of CC10 secreting cells into TFF1 secreting cells and/or goblet cells in upper airways. Nasal turbinate and septal epithelium display different patterns of transdifferentiation.