The IL-1 axis is associated with airway inflammation after O3 exposure in allergic asthmatic patients

Inhalation of Spray-Dried Extract of Salvia rosmarinus Spenn Alleviates Lung Inflammatory, Oxidative, and Remodeling Changes in Asthmatic Rats

INTRODUCTION

For centuries, Salvia rosmarinus Spenn has been applied as folk medicine to cure different diseases due to its anti-inflammatory, antibacterial, antioxidant, antifungal, and antitumor effects. To find bioactive medicinal herbs exerting a protective effect on airway inflammation and remodeling, we assessed the anti-oxidative and anti-inflammatory effects of an aqueous spray-dried extract of Salvia rosmarinus Spenn. (rosemary) in an ovalbumin-induced asthmatic rat model.

METHODS

Rats were randomly divided into normal control (control), asthma, asthma+rosemary extract (RE) (13 mg/kg), asthma+RE (50 mg/kg), and asthma+budesonide groups. After 50 days, animals were anesthetized, and then blood, bronchoalveolar lavage fluid (BALF), and lung tissues were collected for subsequent serological and pathological studies. Histopathology of lung tissues was evaluated by H&E staining. The oxidative stress parameters and airway inflammation factors in BALF and lung tissue were explored.

RESULTS

Using thin layer chromatography, the presence of rosmarinic acid was confirmed in aqueous extract of rosemary. Furthermore, RE markedly decreased immunoglobulin E levels (50 mg/kg; p < 0.001 vs. asthma group) and inflammatory cytokines (50 mg/kg; p < 0.001 vs. asthma group) and increased antioxidant enzymes (50 mg/kg, p < 0.001 vs. asthma group). Furthermore, RE at a concentration of 50 mg/kg obviously reduced the number of inflammatory cells, goblet cells, and pathological changes compared to the asthma group.

CONCLUSION

The results showed that RE administration might prevent or alleviate allergic asthma-related pathological change, probably via antioxidant and anti-inflammatory mechanisms.

Unripe Rubus occidentalis, Ellagic Acid, and Urolithin A Attenuate Inflammatory Responses in IL-1β-Stimulated A549 Cells and PMA-Stimulated Differentiated HL-60 Cells

Unripe Rubus occidentalis (uRO) contains various natural polyphenols with beneficial physiological activities and is particularly rich in ellagic acid (EA). EA has ameliorated type 2 inflammation and airway hyperresponsiveness in animal models of eosinophilic asthma. EA is metabolized by the gut microbiota to urolithin A (UA), which exhibits anti-inflammatory properties. However, it remains unclear whether uRO, EA, and UA reduce inflammatory responses and oxidative stress in respiratory epithelial cells and neutrophils. In this study, inflammation was induced in A549 (human lung epithelial cells) and dHL-60 cells (neutrophil-like cells differentiated from human promyelocytic leukemia HL-60 cells) and treated with various concentrations of water extract of uRO (uRO-w), EA, and UA. EA, uRO-w and UA suppressed the inflammatory cytokine and chemokine levels and reduced the expression of matrix metalloproteinase-9 in A549 cells stimulated with IL-1β. As a result of analyzing the mechanism by which these inflammatory molecules are expressed, it was found that EA, uRO-w, and UA regulated corticosteroid-sensitive mitogen activated protein kinase, nuclear factor κB, and corticosteroid-insensitive AKT. In addition, uRO-w, EA, and UA significantly reduced reactive oxygen species levels in phorbol 12-myristate 13-acetate-stimulated dHL-60 cells and inhibited neutrophil extracellular trap formation. Therefore, our results suggest that uRO-w, EA, and UA are potential therapeutic agents for preventing and treating inflammatory respiratory diseases.

Treatment options in type-2 low asthma

Monoclonal antibodies targeting IgE or the type-2 cytokines interleukin (IL)-4, IL-5 and IL-13 are proving highly effective in reducing exacerbations and symptoms in people with severe allergic and eosinophilic asthma, respectively. However, these therapies are not appropriate for 30-50% of patients in severe asthma clinics who present with non-allergic, non-eosinophilic, "type-2 low" asthma. These patients constitute an important and common clinical asthma phenotype, driven by distinct, yet poorly understood pathobiological mechanisms. In this review we describe the heterogeneity and clinical characteristics of type-2 low asthma and summarise current knowledge on the underlying pathobiological mechanisms, which includes neutrophilic airway inflammation often associated with smoking, obesity and occupational exposures and may be driven by persistent bacterial infections and by activation of a recently described IL-6 pathway. We review the evidence base underlying existing treatment options for specific treatable traits that can be identified and addressed. We focus particularly on severe asthma as opposed to difficult-to-treat asthma, on emerging data on the identification of airway bacterial infection, on the increasing evidence base for the use of long-term low-dose macrolides, a critical appraisal of bronchial thermoplasty, and evidence for the use of biologics in type-2 low disease. Finally, we review ongoing research into other pathways including tumour necrosis factor, IL-17, resolvins, apolipoproteins, type I interferons, IL-6 and mast cells. We suggest that type-2 low disease frequently presents opportunities for identification and treatment of tractable clinical problems; it is currently a rapidly evolving field with potential for the development of novel targeted therapeutics.

Precision medicine in atopic diseases

PURPOSE OF REVIEW

To analyze the status of precision medicine in atopic diseases.

RECENT FINDINGS

Atopic diseases are increasingly recognized as heterogeneous in nature and they can be quite different in severity, response to therapy, triggers, genetic back ground, ancestral risk and type of inflammation. This significant variability in the landscape of atopic diseases is not reflected in the common treatment guidelines that follow 'one fits all' approach for their management. Such an approach is largely based on minimal 'phenotype' elements, such as severity of disease and response to therapy and does not reflect the information accumulate in the last 20 years about particular pathogenic pathways (endotypes) leading to disease (phenotypes) based on biomolecular analysis of the single individuals. Accumulating data have defined asthma allergic rhinitis, food allergy based on their endotypes and clinically relevant phenotypes. In general, atopic diseases can be largely classified as high or low Th2 inflammatory status, which may explain the severity and response to therapy.

SUMMARY

Precision medicine is aiming to use known endotype phenotype to guide specific individualized treatment. The work aimed in deep characterization of diseases to guide the disease management is crucial in light of the availability of ever more precise treatment able to target specific pathways.

Transcriptional Effects of Ozone and Impact on Airway Inflammation

Epidemiological and challenge studies in healthy subjects and in individuals with asthma highlight the health impact of environmental ozone even at levels considered safe. Acute ozone exposure in man results in sputum neutrophilia in 30% of subjects particularly young children, females, and those with ongoing cardiopulmonary disease. This may be associated with systemic inflammation although not in all cases. Chronic exposure amplifies these effects and can result in the formation of asthma-like symptoms and immunopathology. Asthmatic patients who respond to ozone (responders) induce a greater number of genes in bronchoalveolar (BAL) macrophages than healthy responders with up-regulation of inflammatory and immune pathways under the control of cytokines and chemokines and the enhanced expression of remodeling and repair programmes including those associated with protease imbalances and cell-cell adhesion. These pathways are under the control of several key transcription regulatory factors including nuclear factor (NF)-κB, anti-oxidant factors such as nuclear factor (erythroid-derived 2)-like 2 NRF2, the p38 mitogen activated protein kinase (MAPK), and priming of the immune system by up-regulating toll-like receptor (TLR) expression. Murine and cellular models of acute and chronic ozone exposure recapitulate the inflammatory effects seen in humans and enable the elucidation of key transcriptional pathways. These studies emphasize the importance of distinct transcriptional networks in driving the detrimental effects of ozone. Studies indicate the critical role of mediators including IL-1, IL-17, and IL-33 in driving ozone effects on airway inflammation, remodeling and hyperresponsiveness. Transcription analysis and proof of mechanisms studies will enable the development of drugs to ameliorate the effects of ozone exposure in susceptible individuals.

Effects of Exposure to Ozone on the Ocular Surface in an Experimental Model of Allergic Conjunctivitis

Based on previous findings that ozone can induce an inflammatory response in the ocular surface of an animal model and in cultured human conjunctival epithelial cells, we investigated whether exposure to ozone exacerbates symptoms of allergic conjunctivitis. We evaluated the effects of exposure to ozone on conjunctival chemosis, conjunctival injection, corneal and conjunctival fluorescein staining scores, production of inflammatory cytokines in tears, and aqueous tear production in a mouse model of allergic conjunctivitis. To validate our in vivo results, we used interleukin (IL)-1α-pretreated conjunctival epithelial cells as an in vitro substitute for the mouse model. We evaluated whether exposure to ozone increased the inflammatory response and altered oxidative status and mitochondrial function in IL-1α-pretreated conjunctival epithelial cells. In the in vivo study, ozone induced increases in conjunctival chemosis, conjunctival injection, corneal and conjunctival fluorescein staining scores, and production of inflammatory cytokines, accompanied by a decrease in tear volume. In the in vitro study, exposure to ozone led to additional increases in IL-6 and tumor necrosis factor-α mRNA levels, which were already induced by treatment with IL-1α. Ozone did not induce any changes in cell viability. Pretreatment with IL-1α increased the expression of manganese superoxide dismutase, and exposure to ozone led to additional increments in the expression of this antioxidant enzyme. Ozone did not induce any changes in mitochondrial activity or expression of mitochondrial enzymes and proteins related to mitochondrial function, with the exception of phosphor-mammalian target of rapamycin. Treatment with butylated hydroxyanisole, a free radical scavenger, attenuated the ozone-induced increases in IL-6 expression in IL-1α-pretreated conjunctival epithelial cells. Therefore, we conclude that exposure to ozone exacerbates the detrimental effects on the integrity of the ocular surface caused by conjunctival allergic reactions, and further increases the inflammatory response in IL-1α-pretreated conjunctival epithelial cells.