Antagonizing interleukin-5 receptor ameliorates dextran sulfate sodium-induced experimental colitis in mice through reducing NLRP3 inflammasome activation.

Inflammatory bowel disease (IBD) is a condition characterized by inflammation in the gastrointestinal tract. Reducing intestinal inflammation is a promising approach for treating IBD. The nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome, a critical component of the innate immune system, is implicated in the pathogenesis of IBD. Therefore, inhibiting NLRP3 inflammasome activation is a potential therapeutic strategy for IBD. In this study, we investigated the effects of the interleukin-5 (IL-5) receptor antagonist YM-90709 on dextran sulfate sodium-induced experimental colitis in mice. We found that YM-90709 reduced the expressions of IL-1ß and caspase-1 p20 in the colon and ameliorated colitis. Furthermore, we identified YM-90709 as an effective agent for inhibiting NLRP3 inflammasome activation. Knockdown of IL-5 receptor or using an inhibitor of STAT5, a key transcription factor downstream of the IL-5/IL-5 receptor signal pathway, also reduced NLRP3 inflammasome-dependent IL-1ß release and ASC speck formation. Our study is the first to demonstrate that the NLRP3 inflammasome may be a downstream signal of IL-5/IL-5 receptor and that YM-90709 protects against IBD by inhibiting IL-5 receptor. These findings suggest a new strategy for regulating intestinal inflammation and managing IBD.

Naringenin ameliorates atopic dermatitis by inhibiting inflammation and enhancing immunity through the JAK2/STAT3 pathway.

OBJECTIVE: Atopic dermatitis (AD) is an inflammatory skin disease. Naringenin (Nar) possesses an anti-inflammatory property. This paper attempts to discuss the functional mechanism of Nar in AD mice through the Janus kinase 2 (JAK2)/signal transducer and activation of transcription 3 (STAT3) pathway. METHODS: Mouse models of DNFB-induced AD were established and treated with Nar, followed by intraperitoneal injection with the JAK2/STAT3 pathway activator Coumermycin A1. Dermatitis severity was scored and the thickness of right ear was measured. The pathological changes in dorsal skin tissues were observed by HE staining. The number of infiltrated mast cells and eosinophilic granulocytes was counted by TB staining. The serum IgE level and levels of TNF-α, IL-6, IFN-γ, IL-12, and IL-5 in dorsal skin tissues were measured by ELISA. The levels of p-JAK2, JAK2, p-STAT3, and STAT3 were determined by Western blot. RESULTS: Nar decreased dermatitis scores and right ear thickness, alleviated skin lesions, and reduced the number of infiltrated mast cells and eosinophilic granulocytes in AD mice. The serum IgE level and levels of TNF-α, IL-6, IFN-γ, IL-12, and IL-5 in dorsal skin tissues of AD mice were diminished after Nar treatment in a dose-dependent manner. Nar inhibited the activation of the JAK2/STAT3 pathway. The activation of the JAK2/STAT3 pathway partially nullified the therapeutic function of Nar on AD mice. CONCLUSION: Nar protects mice from AD by inhibiting inflammation and promoting immune responses through the inhibition of the JAK2/STAT3 pathway.

Allergen-induced NLRP3/caspase1/IL-18 signaling initiate eosinophilic esophagitis and respective inhibitors protect disease pathogenesis.

The current report describes a stepwise mechanistic pathway of NLRP3/caspase1/IL-18-regulated immune responses operational in eosinophilic esophagitis (EoE). We show that esophageal epithelial cells and macrophage-derived NLRP3 regulated IL-18 initiate the disease and induced IL-5 facilitates eosinophil growth and survival. We also found that A. fumigatus-exposed IL-18-/- mice or IL-18-neutralized mice are protected from EoE induction. Most importantly, we present that intravascular rIL-18 delivery to ΔdblGATA mice and CD2-IL-5 mice show the development of EoE characteristics feature like degranulated and intraepithelial eosinophils, basal cell hyperplasia, remodeling and fibrosis. Similarly, we show an induced NLRP3-caspase1-regulated IL-18 pathway is also operational in human EoE. Lastly, we present the evidence that inhibitors of NLRP3 and caspase-1 (MCC950, BHB, and VX-765) protect A. fumigatus- and corn-extract-induced EoE pathogenesis. In conclusion, the current study provides a new understanding by implicating NLRP3/caspase1-regulated IL-18 pathway in EoE pathogenesis. The study has the clinical significance and novel therapeutic strategy, which depletes only IL-18-responsive pathogenic eosinophils, not naïve IL-5-generated eosinophils critical for maintaining innate immunity.

Regulatory T-cells and IL-5 mediate pain outcomes in a preclinical model of chronic muscle pain.

Fibromyalgia (FM) is a chronic musculoskeletal pain disorder primarily diagnosed in women. Historically, clinical literature focusing on cytokines and immune cells has been inconsistent. However, recent key studies show several layers of immune system dysfunction in FM. Preclinically, studies of the immune system have focused on monocytes with little focus on other immune cells. Importantly, T-cells are implicated in the development and resolution of chronic pain states, particularly in females. Our previous work showed that monocytes from women with FM produced more interleukin 5 (IL-5) and systemic treatment of IL-5 reversed mechanical hypersensitivity in a preclinical model of FM. Typically, IL-5 is produced by TH2-cells, so in this study we assessed T-cell populations and cytokine production in female mice using the acid-induced chronic muscle pain model of FM before and after treatment with IL-5. Two unilateral injections of pH4.0 saline, five days apart, into the gastrocnemius muscle induce long-lasting widespread pain. We found that peripheral (blood) regulatory Thelper-cells (CD4+ FOXP3+) are downregulated in pH4.0-injected mice, with no differences in tissue (lymph nodes) or CD8+ T-cell populations. We tested the analgesic properties of IL-5 using a battery of spontaneous and evoked pain measures. Interestingly, IL-5 treatment induced place preference in mice previously injected with pH4.0 saline. Mice treated with IL-5 show limited changes in T-cell populations compared to controls, with a rescue in regulatory T-cells which positively correlates with improved mechanical hypersensitivity. The experiments in this study provide novel evidence that downregulation of regulatory T-cells play a role in chronic muscle pain pathology in the acidic saline model of FM and that IL-5 signaling is a promising target for future development of therapeutics.

Canavalia gladiata Pod Extract Mitigates Ovalbumin-Induced Asthma Onset in Male BALB/c Mice via Suppression of MAPK.

Asthma is one of the most common inflammatory diseases of the lung worldwide. There has been considerable progress in recent studies to treat and prevent allergic asthma, however, various side effects are still observed in clinical practice. Six-week-old male BALB/c mice were orally administered with either sword bean pod extracts (SBP; 100 or 300 mg/kg) or dexamethasone (DEX; 5 mg/kg) once daily over 3 weeks, followed by ovalbumin sensitization (OVA/Alum.; intraperitoneal administration, 50 µg/2 mg/per mouse). Scoring of lung inflammation was performed to observe pathological changes in response to SBP treatment compared to OVA/Alum.-induced lung injury. Additionally, inflammatory cytokines were quantified in serum, bronchoalveolar lavage fluid (BALF), and lung tissue using ELISA and Western blot analyses. SBP treatment significantly reduced the infiltration of inflammatory cells, and release of histamine, immunoglobulin E, and leukotriene in serum and BALF. Moreover, the therapeutic effect of SBP was also assessed to analyze the inflammatory changes in the lung tissues. SBP markedly suppressed the activation of the MAPK signaling pathway and the expression of key inflammatory proteins (e.g., TNF-α) and Th2 type cytokines (IL-5 and IL-13). SBP was effective in ameliorating the allergic inflammation against OVA/Alum.-induced asthma by suppressing pulmonary inflammation.

Orally administered solasodine, a steroidal glycoalkaloid, suppresses ovalbumin-induced exaggerated Th2-immune response in rat model of bronchial asthma.

Bronchial asthma is a chronic lung disorder, that affects an estimated 262 million people worldwide, thereby, causing a large socio-economic burden. Drug molecules from natural sources have exhibited a good promise in providing an alternative therapy in many chronic ailments. Solasodine, a glycoalkaloid has received an immense interest due to its large pharmacological and industrial value, however, its usefulness in asthma control has not been investigated till date. In this work, solasodine was tested for its ability to reverse several characteristics of bronchial asthma induced by intraperitoneal injection of ovalbumin (OVA) and aluminium hydroxide in experimental rats. Treating asthmatic animals with solasodine (1 mg/kg b.w. or 10 mg/kg b.w.) or dexamethasone (2.5 mg/kg b.w.) reversed OVA-induced airway hyperresponsiveness, infiltration of inflammatory cells and histamine levels in the airways. Furthermore, as compared to OVA-control rats, allergen-induced elevated levels of IgE, nitrites, nitric oxide, and pro-inflammatory mediators, including TNF-α, IL-1ß, LTD-4, and Th2-cytokines, particularly, IL-4, IL-5 were remarkably reduced in both bronchoalveolar lavage fluid and blood. These findings are supported by significant protection offered by various treatments against OVA-induced airway inflammation and mast cell degranulation in mesenteric tissues. Further, In-silico molecular docking studies performed to determine inhibitory potential of solasodine at IL-4 and IL-5, demonstrated strong affinity of phytocompound for these receptors than observed with antagonists previously reported. Results of current study imply that solasodine has therapeutic promise in allergic asthma, presumably due to its ability to prevent mast cell degranulation and consequent generation of histamine and Th2-associated cytokines in airways.

Immunomodulatory Effect of SINA 1.2 Therapy Protocol in Asthmatic Mice Model: A Combination of Oxymel and Sauna.

Alternative medicine, has become popular in asthmatic patients. We evaluated the immunomodulatory effects of SINA 1.2 therapy protocol derived from Persian medicine in an asthmatic mice model. Forty-two male BALB/c mice divided into six groups: one control (sham) and five sensitized groups (by parenteral injection of 20 µg ovalbumin in 100 µL normal saline plus 50 µL alum on days 1 and 14). Sensitized groups were as: untreated, budesonide (1 mg nebulized budesonide: 200 µg/puff every 5 min for 25 min), dry sauna (30 min, 37°C), oral oxymel (gavaged: 0.2 mL of the syrup plus 0.8 mL of water), and SINA protocol No.1.2 (oxymel followed by sauna) groups. Treatments were given for 10 days from day 23 to 33 then sacrificed. Significant gene expression reduction of interleukin(IL)-4, IL-5, and MUC5AC and increase of interferon(IFN)-γ and IFN-γ/IL-4 ratio and decreased perivascular and peribronchial inflammation, goblet cell hyperplasia, and subsequent mucus hypersecretion in SINA group were seen compared to untreated group. SINA lowered IL-5 and MUC5AC gene expression levels similar to the budesonide and acted better than budesonide in increasing IFN-γ gene expression up to normal level. Compared with the asthma group, sauna alone only affected MUC5AC and IFN-γ gene expressions and oxymel alone, only reduced IL-4 gene expression, perivascular and peribronchial inflammation, and mucus hypersecretion. It seems that SINA therapy alleviates asthma via immune modulation of pro-inflammatory cytokines and improvement of pathological changes in ovalbumin-induced asthma in mice, supporting the notion of innate healing power mentioned in Persian medicine literature.

[Effect of Echinococcus granulosus hydatid cyst fluid protein on allergic rhinitis induced by ovalbumin in mice].

OBJECTIVE: To investigate the protective effect of Echinococcus granulosus hydatid cyst fluid protein (HCFP) on ovalbumin (OVA)-induced allergic rhinitis (AR) in mice. METHODS: Twenty-four BALB/c mice at ages of 8 to 10 weeks, each weighing approximately 20 g, were randomly divided into four groups, including groups A (blank control group), B (blank intervention group), C (AR model group) and D (AR+HCFP intervention group), with 6 mice in each group. On days 0, 2, 4, 6, 8, 10 and 12, mice in groups A, B, C and D were injected with 200 µL sterile phosphate buffered saline (PBS), 200 µL sterile PBS containing 20 µg HCFP, 200 µL sterile PBS containing 50 µg OVA and 5 mg Al(OH)3 gel, and 200 µL sterile PBS containing 50 µg OVA, 5 mg Al(OH)3 gel and 20 µg HCFP, respectively. On days 14 to 20, mice in groups A, B, C and D were administered with 40 µL sterile PBS, 40 µL sterile PBS containing 20 µg HCFP, 40 µL sterile PBS containing 2 mg OVA and 40 µL sterile PBS containing 2 mg OVA and 20 µL HCFP by nasal drop, respectively. Mouse behavioral changes were observed and behavioral scores were estimated. The serum levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), IL-5, IL-10, transforming growth factor-ß (TGF-ß) and OVA-specific IgE antibody (OVA-sIgE) were measured using enzyme-linked immunosorbent assay (ELISA), and the pathological changes of mouse nasal mucosa were observed by hematoxylin and eosin (HE) staining. RESULTS: The mean behavioral score was significantly greater in Group C (6.83 ± 0.50) than in groups A (1.17 ± 0.52) and B (1.33 ± 0.52) (P < 0.05), while a lower mean behavioral score was estimated in Group D (3.50 ± 0.50) than in Group C (P < 0.05). There were significant differences among the groups in terms of serum IFN-γ (F = 4.08, P < 0.05), IL-4 (F = 275.90, P < 0.05), IL-5 (F = 96.82, P < 0.05), IL-10 (F = 77.67, P < 0.05), TGF-ß (F = 9.98, P < 0.05) and OVA-sIgE levels (F = 44.69, P < 0.05). The serum IFN-γ level was significantly lower in Group C than in groups A, B and C (P < 0.05), and the serum levels of IL-4, IL-5 and OVA-sIgE were significantly higher in Group C than in groups A, B and C (P < 0.05), while the serum IL-10 and TGF-ß levels were significantly greater in Group D than in Group C (P < 0.05). Microscopy showed apparent loss of nasal mucosa cilia, increased number and enlargement of goblet cells, interstitial edema and submucous vascular dilation in Group C, while the pathological changes of nasal mucosa were alleviated in Group D relative to Group C. CONCLUSIONS: E. granulosus HCFP has a protective activity against OVA-induced allergic rhinitis in mice.

Yanghe Decoction Effectively Alleviates Lung Injury and Immune Disorder in Asthmatic Mice Induced by Ovalbumin.

Objective: To probe into the ameliorative effect of Yanghe Decoction on pulmonary injury and immunologic derangement in asthmatic mice. Methods: C57BL/6 mice were randomized into control (Con), Model, and Yanghe Decoction (YHF) groups, with 12 in each. The asthma model of adult female mice was induced by ovalbumin in the Model group, and the YHF group was treated by Yanghe Decoction on the basis of asthma modeling. The Con group received the same amount of normal saline. Inspiratory resistance (Ri), expiratory resistance (Re), lung compliance (CL), and maximal voluntary ventilation (MVV) were measured after modeling. Lung tissue was collected for the measurement of interleukin (IL)-4, IL-5, IL-6, IL-10, IL-13, and tumor necrosis factor-α (TNF-α) by ELISA kits. Combined with HE staining and PAS staining, the pathological alterations of the lung in each group were observed, and CD4+, Th2, and Th1 contents were determined by flow cytometry (FCM). Results: The pulmonary function (PF) test revealed notably reduced Ri and Re as well as enhanced CL and MVV in asthmatic mice after the application of Yanghe Decoction. Yanghe Decoction dramatically ameliorated the pathological changes of lung tissue in asthmatic mice, as demonstrated by the staining results. ELISA results showed that Yanghe Decoction validly reduces lung tissue IL-4, IL-5, IL-6, IL-13, TNF-α and upregulates IL-10 in asthmatic mice. FCM indicated that Yanghe Decoction obviously reduced the number of Th1 and Th2 cells in asthmatic mice, although it caused the decrease of CD4+ cells, but the difference was not statistically significant. Conclusions: Yanghe Decoction can effectively ameliorate the inflammatory reaction, immune cell disorder, and PF injury in ovalbumin-induced asthmatic mice.

The consequences of not having eosinophils.

Several lines of evidence suggest that deficiency of eosinophils is not associated with any characteristic abnormality. Patients lacking eosinophils, in the setting of immunodeficiency or as a consequence of IgG-mediated eosinophil precursor destruction, do not display any distinguishing abnormalities related to eosinophil reduction. The observation that eosinophil-deficient mice do not display any distinctive syndrome or failure of their health is evidence that, under ordinary laboratory conditions, the eosinophil does not play a critical role in the well-being of mammals. Observations that monoclonal antibodies to interleukin-5 (IL-5) are well tolerated appear unsurprising in light of these findings. For example, patients with the hypereosinophilic syndrome have received mepolizumab, an anti-IL-5 monoclonal antibody, for as long as 6 years and have not developed any characteristic set of adverse events. Safety data for reslizumab, another anti-IL-5 monoclonal antibody, and benralizumab, a monoclonal antibody to the IL-5 receptor α-chain, are comparatively limited, especially for benralizumab, although reports of administration of these antibodies to humans suggest that they are well tolerated. Thus, data to the present suggest that reduction of eosinophils appears to have no characteristic ill effects on normal health, and monoclonal antibodies that deplete eosinophils have the potential to be widely employed in the treatment of eosinophil-associated diseases.

Evolution of inflammation in nonalcoholic fatty liver disease: the multiple parallel hits hypothesis.

Whereas in most cases a fatty liver remains free of inflammation, 10%-20% of patients who have fatty liver develop inflammation and fibrosis (nonalcoholic steatohepatitis [NASH]). Inflammation may precede steatosis in certain instances. Therefore, NASH could reflect a disease where inflammation is followed by steatosis. In contrast, NASH subsequent to simple steatosis may be the consequence of a failure of antilipotoxic protection. In both situations, many parallel hits derived from the gut and/or the adipose tissue may promote liver inflammation. Endoplasmic reticulum stress and related signaling networks, (adipo)cytokines, and innate immunity are emerging as central pathways that regulate key features of NASH.

Effects of anti-IL-5 monoclonal antibody on the murine model of nasal allergy.

IL-5 is known to be closely related to the infiltration, activation and proliferation of eosinophils. In this study, we evaluated the in vivo effects of anti-IL-5 monoclonal antibody (mAb) in the murine model of nasal allergy. The mAb treatment inhibited the antigen-induced late phase eosinophilia, but had no effects on the number of basophilic cells. It also inhibited early phase nasal symptoms, and tended to inhibit histamine hypersensitivity. These findings suggest that IL-5 plays an important role in the pathogenesis of allergic nasal disorders.

Effect of inhaled interleukin-5 on airway hyperreactivity and eosinophilia in asthmatics.

In order to investigate the role of interleukin-5 (IL-5) in airway hyperreactivity and eosinophilia, we observed the effect of inhaled recombinant human IL-5 on airway responsiveness to methacholine and cell populations in induced sputum in eight patients with allergic bronchial asthma using a placebo-controlled study design. Our results demonstrated that the inhalation of IL-5 did not alter lung function in allergic asthmatics. In the control experiments receiving either vehicle or 0.4 ng of endotoxin, methacholine PC20 values did not change nor did the numbers of eosinophils or eosinophil cationic protein (ECP) sputum values change from baseline. In contrast, after IL-5 inhalation, methacholine PC20 fell from baseline (0.90 +/- 166 mg/ml) to 0.32 +/- 1.63 mg/ml (p < 0.01) at 24 h, and to 0.55 +/- 1.49 mg/ml (p < 0.05) at 48 h. Accompanying this increased airway sensitivity was a significant eosinophilia and elevated concentrations of ECP in induced sputum. Our data provided direct evidence that IL-5 increases airway responsiveness and infiltration of activated eosinophils into the airway in patients with allergic bronchial asthma. It also could be concluded that the observed airway hyperreactivity and eosinophilia were not endotoxin related.