Effect of IL‑7 on Th17 cell responses in a mouse model of neutrophilic asthma

THE LEVEL OF REACTIVE OXYGEN SPECIES AS A MARKER OF ASTHMA SEVERITY IN CHILDREN

OBJECTIVE

The aim of the research was to assess the reactive oxygen species (ROS) levels in granulocytes of patients with asthma.

PATIENTS AND METHODS

Materials and methods: The study involved 35 children aged 5 to 17 years. 26 children with persistent asthma, partially controlled course in the period of exacerbation were divided into groups: 1 group - mild asthma (n = 12), group 2 - moderate asthma (n = 7) group 3 - severe asthma (n = 7) and control group included almost healthy children (n = 9). ROS levels in granulocytes were evaluated using BD FACSDiva™. The spirographic complex was used to assess the function of external respiration.

RESULTS

Results: The level of ROS in granulocytes of patients with severe asthma was significantly reduced compared with children in the control group and patients with mild and moderate asthma (p₁-₃ = 0.0003, p₂-₃ = 0.0017, p c-₃ = 0.0150). The concentration of ROS in granulocytes ≤ 285 a.u. was prognostically significant with high specificity and sensitivity with severe asthma.

CONCLUSION

Conclusions: The concentration of ROS levels in neutrophils in patients with severe asthma probably reflected the suppression of their products, which suggests the depletion of the reserve capacity of neutrophils. Decreased concentrations of reactive oxygen species in children with asthma can be considered as a possible marker of asthma severity.

Tiotropium bromide has a more potent effect than corticosteroid in the acute neutrophilic asthma mouse model

Background

Neutrophilic asthma (NeuA) is usually resistant to corticosteroids. Tiotropium bromide (TIO) is a bronchodilator that is used as an add-on therapy to inhaled corticosteroid and long-acting β2 agonist in asthma treatment. However, the role of TIO in NeuA is not fully known. Thus, the aim of this study was to evaluate the effect of TIO on NeuA compared to that of corticosteroids.

Methods

C57BL/6 female mice were sensitized with ovalbumin and lipopolysaccharide to induce neutrophilic inflammation. Dexamethasone (DEX) was administered on days 14, 17, 20, and 23. TIO was inhaled on days 21, 21, and 23. On day 24, mice were sacrificed. Airway hyper-responsiveness, levels of cytokines in bronchoalveolar lavage (BAL) and lung homogenates, and lung tissue histopathology were compared between the two groups.

Results

Neutrophil counts, T helper 2 cells (T_H2)/T_H17 cytokines, and pro-inflammatory cytokine in BAL fluids were elevated in the NeuA group. TIO group showed lower total cells, neutrophil counts, and eosinophil counts in BAL fluids than the DEX group (p<0.001, p<0.05, and p<0.001, respectively). Airway resistance was attenuated in the TIO group but elevated in the NeuA group (p<0.001). Total protein, interleukin (IL)-5, and IL-17A levels in BAL fluids were lower in the TIO group than in the NeuA group (all p<0.05).

Conclusion

TIO showed more potent effects than DEX in improving airway inflammation and attenuating airway resistance in NeuA.

AKR1C1 alleviates LPS‑induced ALI in mice by activating the JAK2/STAT3 signaling pathway

Acute lung injury (ALI) is a respiratory tract disease characterized by increased alveolar/capillary permeability, lung inflammation and structural damage to lung tissues, which can progress and transform into acute respiratory distress syndrome (ARDS). Although there are several treatment strategies available to manage this condition, there is still no specific cure for ALI. Aldo-keto reductase family 1 member C1 (AKR1C1) is a member of the aldo-keto reductase superfamily, and is a well-known Nrf2 target gene and an oxidative stress gene. The aim of the present study was to investigate the effects of AKR1C1 on a lipopolysaccharide (LPS)-induced ALI model. After mice received LPS treatment, the mRNA expression levels of AKR1C1 in the bronchoalveolar lavage fluid and serum were measured using reverse transcription-quantitative PCR and its relationship with the inflammatory factors and malondialdehyde levels were determined using correlation analysis. Next, AKR1C1 was overexpressed or knocked out in mice, and subsequently ALI was induced in mice using LPS. The severity of ALI, oxidative stress and inflammation in the lungs were measured, and the potential involvement of the Janus kinase 2 (JAK2)/signal transduction activator of transcription 3 (STAT3) signaling pathway was assessed by measuring the changes of lung injury parameters after the agonists of JAK2/STAT3 pathway, including interleukin (IL)-6 and colivelin, were administrated to mice. The results revealed that AKR1C1 expression was decreased in the LPS-induced ALI mouse model. AKR1C1 expression was inversely correlated with serum tumor necrosis factor-α, IL-6 and malondialdehyde levels, and positively correlated with serum IL-10 levels. AKR1C1 overexpression significantly attenuated lung injury, as shown by the changes in Evans blue leakage in the lung, lung wet/dry weight ratio, PaO₂/FIO₂ ratio, survival rate of mice and histological lung changes. In addition, the JAK2/STAT3 signaling pathway was significantly deactivated by AKR1C1^+/+. When AKR1C1^+/+ mice were treated with JAK2/STAT3 agonists, the effects of AKR1C1 overexpression on lung injury and oxidative stress were abolished. In conclusion, AKR1C1 may protect against oxidative stress and serve as a negative regulator of inflammation in ALI/ARDS. In addition, the JAK2/STAT3 signaling pathway could participate in the protective effects of AKR1C1 against ALI.

miR‑29a‑3p regulates the epithelial‑mesenchymal transition via the SPARC/ERK signaling pathway in human bronchial epithelial cells

Neutrophilic asthma (NA) is a subtype of asthma that responds poorly to corticosteroid treatment. In certain diseases, microRNA (miR)‑29a‑3p is considered to be a key regulatory molecule for remodeling of the extracellular matrix. However, the effect of miR‑29a‑3p on airway remodeling is unknown. The present study aimed to investigate the role of miR‑29a‑3p in NA. A mouse model of NA was established and these animals were compared to normal controls. Both groups of mice were subjected to lung function tests and histopathological analysis. Human bronchial epithelial cells (16HBE) were grown in culture and incubated with secreted protein acidic rich in cysteine (SPARC) and a miR‑29a‑3p mimic. The expression of miR‑29a‑3p, SPARC and epithelial‑mesenchymal transition (EMT)‑related markers were measured using reverse transcription‑quantitative PCR and western blotting. Luciferase reporter assay was performed to identify the direct regulatory relationship between miR‑29a‑3p and SPARC. miR‑29a‑3p expression was significantly decreased, while SPARC expression was increased in the NA mouse model with a phenotype of EMT. Overexpression of SPARC downregulated the expression of E‑cadherin, while it increased the expression of vimentin in 16HBE cells. miR‑29a‑3p administration reversed the SPARC‑induced effects on E‑cadherin and vimentin expression. Luciferase assays confirmed that SPARC was the target gene for miR‑29a‑3p. Furthermore, SPARC overexpression increased the protein expression of phosphorylated (p)‑ERK, while transfection with miR‑29a‑3p mimics significantly inhibited this increase. The data suggested that EMT in the NA mouse model was associated with decreased levels of miR‑29a‑3p and elevated SPARC. Furthermore, SPARC could induce the formation of EMT in 16HBE cells in vitro and this was directly targeted by miR‑29a‑3p and mediated by p‑ERK, suggesting that miR‑29a‑3p may participate in the airway remodeling of NA.

Induction of T helper 17 cell response by interleukin-7 in patients with primary cutaneous melanoma

Interleukin (IL)-7 plays a vital role in proliferation and activation of T cells, however, its signaling through CD127 is impaired in T cells in cancers and chronic infections. The mechanisms underlying T helper 17 (Th17) cell responses by IL-7 in melanoma remain not fully understood. The aim of this study was to assess the effect of IL-7 signaling on Th17 responses in patients with primary cutaneous melanoma. Healthy and primary cutaneous melanoma donors were selected for this study of Th17 cell function. IL-17+CD4+ Th17 cells and CD127 expression on Th17 cells were determined by flow cytometry. Cytokine level was measured by ELISA. Peripheral and tissue-infiltrating CD4+ T cells were isolated using magnetic beads, and then stimulated with IL-7 and/or signal transducer and activator of transcription 5 inhibitor. Activated signaling molecules were analyzed by flow cytometry. Peripheral and tumor-infiltrating Th17 cells percentage was decreased, while peripheral IL-7 level was also reduced in melanoma patients. There was no significant difference of CD127 expression on Th17 cells between melanoma patients and controls. Antiapoptotic protein Bcl-2 was downregulated, whereas proapoptotic protein-activated caspase-3 was upregulated in peripheral and tissue-infiltrating Th17 cells in melanoma patients. Higher concentration of IL-7 (10 ng/mL), but not lower IL-7 concentration (1 ng/mL), promoted Bcl-2 expression and decreased caspase-3 expression in Th17 cells in melanoma patients. Inhibition of signal transducer and activator of transcription 5 resulted in the downregulation of Bcl-2 while upregulation of caspase-3 in Th17 cells. The present data suggested that reduced IL-7 responsiveness might be insufficient for Th17 activation in patients with primary cutaneous melanoma.

sRAGE Inhibits the Mucus Hypersecretion in a Mouse Model with Neutrophilic Asthma

Background: Neutrophilic asthma (NA) may result in irreversible airflow limitations. Soluble advanced glycosylation receptor (sRAGE) has been shown to be associated with neutrophilic airway inflammation. However, the association between sRAGE and mucus hypersecretion in NA remains unknown. This study aims to assess the function of sRAGE on mucus hypersecretion.Methods: A NA mouse model was established and treated with adeno-associated virus 9 (AAV9)-sRAGE and inhibitors. Collagen deposition and goblet cell hyperplasia in the lungs were evaluated by periodic acid-Schiff (PAS) and Masson staining. sRAGE and mucin levels in bronchoalveolar lavage fluid were measured by ELISA. Pathway molecule expression levels were determined by RT-qPCR and western blotting.Results: The results showed that the NA mouse model exhibited airway mucus hypersecretion. Mice can be effectively transfected by AAV9-sRAGE via tail-vein injection and intranasal drip. AAV9-sRAGE increased the sRAGE levels but it inhibited the collagen deposition, the PAS score, as well as the expression of MUC5AC and MUC5B. Inhibitors of high-mobility group protein 1 (HMGB1), receptor for advanced glycation end product (RAGE) and phosphatidylinositol 3-kinase (PI3K) suppressed the MUC5AC levels in NA mice as well as in cultured HMGB1-induced human bronchial epithelial cells. Furthermore, the phospho- extracellular signal-regulated kinase (ERK) protein in NA was increased while the sRAGE intervention inhibited this elevation.Conclusions: These results suggest that sRAGE may be a potential target for the treatment of mucus hypersecretion in NA.

Relationship between Th17-mediated immunity and airway inflammation in childhood neutrophilic asthma

BACKGROUND

The pathogenetic mechanisms of neutrophilic asthma are not well understood now. Whether T helper (Th)17-mediated immunity contributes to the pathogenesis of neutrophilic asthma in human is still under investigation. The aim of this study was to explore the relationship between Th17-mediated immunity and airway inflammation in childhood neutrophilic asthma.

METHODS

Twenty-eight children with exacerbated asthma and without using any glucocorticoids were divided into three groups: eosinophilic asthma (EA, n = 12) group, neutrophilic asthma (NA, n = 10) group and paucigranulocytic asthma (PGA, n = 6) group according to the induced sputum cytology. Ten healthy children were recruited as healthy control (HC, n = 10) group. Peripheral Th17 and Th2 cells, and the expression of Ki-67 in peripheral Th17 cells were detected by flow cytometry. The mRNA expression of retinoic acid-related orphan receptor γt (RORγt) in peripheral blood mononuclear cells (PBMCs) was detected by qRT-PCR. The concentrations of IL-17, IL-8 and IL-5 in sputum, as well as IL-17 in plasma and culture supernatant of activated PBMCs were measured by ELISA.

RESULTS

The percentage of Th17 cells in peripheral Th cells, and the concentrations of IL-17, IL-8 in sputum, as well as IL-17 in culture supernatant of activated PBMCs were all increased in NA group, and positively correlated with neutrophil level in sputum and with each other. Also, the mRNA expression of RORγt in PBMCs and Ki-67 positivity in peripheral Th17 cells were both increased in NA group. The percentage of Th2 cells in peripheral Th cells, and the concentration of IL-5 in sputum were both increased in EA group, and positively correlated with eosinophil level in sputum and with each other.

CONCLUSIONS

Both Th17- and Th2-mediated immunity are involved in the pathogenesis of childhood asthma. There is predominance of Th17-mediated immunity and Th17 cells proliferation in childhood neutrophilic asthma.

TMT-based quantitative proteomics reveals suppression of SLC3A2 and ATP1A3 expression contributes to the inhibitory role of acupuncture on airway inflammation in an OVA-induced mouse asthma model

Asthma is a chronic airway inflammatory disease and acupuncture is frequently used in patients suffering from asthma in clinic. However, the regulatory mechanism of acupuncture treatment in asthma is not fully elucidated. We sought to investigate the effectiveness of acupuncture on asthma and the associated regulatory mechanism. An ovalbumin (OVA)-induced mouse asthma model was established and the effect of acupuncture on airway hyperresponsiveness (AHR), mucus hypersecretion and inflammation was assessed. Tandem mass tag (TMT)-based quantitative proteomics analysis of lung tissue and bioinformatics analysis were performed. Our results revealed that the OVA-induced mouse asthma model was successfully established with the significantly elevated AHR to methacholine (Mch), and acupuncture was effective in attenuation of AHR to Mch, peribronchial and perivascular inflammation and mucus production. The inflammatory cells around the airways, mucous secretion as well as levels of IgE, CCL5, CCL11, IL-17A in bronchoalveolar lavage fluid (BALF) and IL-4, IL-5 and IL-13 levels in serum were siginificantly inhibited by acupuncture. TMT-based quantitative proteomics analysis found that a total of 6078 quantifiable proteins were identified, and 564 (334 up-regulated and 230 down regulated) differentially expressed proteins (DEPs) were identified in OVA-induced asthma model group (A) versus normal control group (NC). Acupuncture treatment resulted in 667 DEPs (416 up-regulated and 251 down regulated) compared with A group, and 86 overlapping DEPs were identified in NC, A and AA groups. Among the 86 overlapping DEPs, we identified 41 DEPs regulated by acupuncture. Based on the above data, we performed a systematic bioinformatics analysis of the 41 DEPs, and results showed that these 41 DEPs were predominantly related to 4 KEGG pathways including SNARE interactions in vesicular transport, ferroptosis, endocrine and other factor-regulated calcium reabsorption, and protein digestion and absorption. DEPs of SLC3A2 and ATP1A3 expression levels were verified by immumohistochemical staining. Mice in OVA-induced asthma model group had elevated SLC3A2 and ATP1A3 expression and acupuncture had the ability to downregulate SLC3A2 and ATP1A3 protein expression. Furthermore, acupuncture reduced the MDA level and increased the GSH and SOD levels in the lung tissue. Taken together, our data suggested that acupuncture was effective in treating asthma by attenuation of AHR, mucus secretion and airway inflammation, and the mechanism was associated with regulation of ferroptosis, SLC3A2 and ATP1A3 protein expression as well as oxidative stress. Results from our experiments revealed the anti-inflammatory effect of acupuncture in OVA-induced mouse asthma model, leading to a more effective approach to be chosen by patients in clinic.