NLRP3 inflammasome activity is upregulated in an in-vitro model of COPD exacerbation.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is an inflammatory disease characterized by a progressive and irreversible deterioration of lung function. Exacerbations of COPD have prolonged negative effects on pulmonary function and a major impact on health status and outcomes. NLRP3 inflammasome is a cardinal component of the inflammatory response, with marked evidence in stable and exacerbations of COPD. The aim of our study was to evaluate the NLRP3 inflammasome activity during COPD exacerbation by using an in vitro model. METHODS: A549 cells were stimulated with different concentrations (10%, 4%, 2%) of cigarette smoke extract (CSE) with or without LPS (0.1µg/ml) for 24 hours. Cell viability was assessed by using XTT test. Levels of inflammatory cytokines (IL-8, MCP-1, and IL-1ß) were measured by ELISA and the activity level of NLRP-3 was evaluated by flow cytometry. RESULTS: Cells exposed to CSE present an increase in inflammatory cytokines (IL-8 and MCP-1) production in a dose-dependent manner. Incubation with LPS to these cells results in higher levels of IL-8 and MCP-1 compared to stimulation of CSE alone. NLRP3 inflammasome activity and IL-1ß levels were significantly increased in cells exposed to both CSE and LPS compared to CSE alone. CONCLUSIONS: NLRP3 inflammasome is upregulated in an in-vitro model of COPD and COPD exacerbation. Our findings provide novel biomarkers for COPD exacerbation and may present new targets for future research.

Epicutaneous Exposure to Peanut Oil Induces Systemic and Pulmonary Allergic Reaction in Mice.

BACKGROUND: The prevalence of peanut allergy (PA) is constantly on the rise. Atopic dermatitis (AD) is a major risk factor for developing food allergy. Some bath oils and skin creams used for treating AD contain peanut oil, and it has been suggested that exposure to peanut allergens through a disrupted skin barrier is a potential cause of PA. Our aim was to investigate whether application of peanut oil to irritated skin causes a systemic or respiratory allergic response to peanuts in an animal model. METHODS: BALB/c mice underwent epicutaneous sensitization with either peanut oil (PM, n = 9) or phosphate buffered solution (controls, n = 9) daily for 5 consecutive days. Ten days after the last exposure the mice were challenged with intranasal peanut protein for 5 consecutive days. Bronchial alveolar lavage fluid was collected for cellular studies and measurement of cytokine levels. Sera were collected for immunoglobulin E (IgE) measurement. RESULTS: Epicutaneous peanut oil sensitization increased leukocyte and eosinophil counts and interleukin-13 levels (p = 0.003, p = 0.0006 and p = 0.03, respectively), in addition to increasing total serum IgE (p = 0.03). CONCLUSIONS: The results suggest that topical application of peanut oil may play a role in the etiology of PA.

Aging leads to impaired epicutaneous sensitization that causes attenuated allergy and pulmonary inflammation in mice.

Aging is associated with altered decreased barrier function in the skin, which can lead to different types of immunoglobulin E (IgE)-mediated sensitization to environmental allergens. Yet, allergen-specific respiratory sensitization among the elderly is not well described. The aim of this study was to investigate the effect of aging on allergic pulmonary inflammation induced by epicutaneous sensitization of mechanically irritated skin in mice. For this purpose, 6-week-, 6-month-, and 18-month-old female BALB/c mice, underwent epicutaneous sensitization with ovalbumin (OVA) or phosphate buffered saline (PBS), followed by an inhaled OVA challenge. Blood OVA-specific IgE levels measured after epicutaneous sensitization, as well as, bronchial alveolar lavage fluids (BALF) leucocyte, eosinophil, and cytokine levels measured after OVA inhalation challenge were similar among the 6-week-old (young) and 6-month-old (adult) groups. However, significantly decreased levels of systemic OVA IgE, and BALF leukocyte, eosinophil and T helper cell type 2 cytokine levels, were measured after OVA inhalation challenge in elderly (18-month-old) mice compared to the other groups of mice. In addition, interleukin-10 (IL-10), a regulatory suppressor cytokine, was more abundant in the BALF of the elderly group after epicutaneous sensitization and inhalation challenge. Our results suggest that elderly mice have a reduced allergic response to induced sensitization with OVA, possibly regulated by increased IL-10 levels.

Topical tacrolimus for the management of acute allergic conjunctivitis in a mouse model.

BACKGROUND: Acute allergic conjunctivitis is a constantly challenging condition that often requires steroids for effective management. Alternative treatment options are needed due to the potential side effects of steroids. Tacrolimus has been used for vernal/atopic conjunctivitis. The aim of our study was to investigate the therapeutic effect of topical administration of 0.03 % tacrolimus (eye drops or ointment) in comparison to 0.1 % dexamethasone in a mouse model of acute allergic conjunctivitis. METHODS: BALB/c mice were sensitized by an intraperitoneal injection of 10 µg/0.2 ml ovalbumin (OVA) absorbed on ALUM (2.0 mg) on days 1 and 8. They were challenged by topical instillation of 2 µl of 15 % OVA (absorbed in 10 % glycerol) twice daily, on days 15-21. Treatment was administered twice daily on days 17-21. Mice were randomly assigned topical treatment groups: Group 1, 0.1 % dexamethasone drops; Group 2, 0.03 % tacrolimus drops; Group 3, 0.03 % tacrolimus ointment; Group 4 PBS drops (control). On day 22 all mice underwent clinical evaluation, blood sampling for IgE levels, and conjunctivas were removed for eosinophil counting. RESULTS: IgE and OVA-specific IgE levels were similar among all groups, demonstrating induction of allergic reaction in all mice. Significantly lower clinical scores were found among all treated groups as compared to controls (P < 0.001), while no significant difference was found among the three treatment groups (P > 0.05). Conjunctival eosinophil counts were significantly lower in Group 1 (P < 0.05) as compared to the other groups. CONCLUSIONS: The clinical efficacy of topical 0.03 % tacrolimus was similar to 0.1 % dexamethasone for acute allergic conjunctivitis.