Aeroallergen Der p 2 induces apoptosis of bronchial epithelial BEAS-2B cells via activation of both intrinsic and extrinsic pathway

Mechanisms of airway epithelial injury and abnormal repair in asthma and COPD

The airway epithelium comprises of different cell types and acts as a physical barrier preventing pathogens, including inhaled particles and microbes, from entering the lungs. Goblet cells and submucosal glands produce mucus that traps pathogens, which are expelled from the respiratory tract by ciliated cells. Basal cells act as progenitor cells, differentiating into different epithelial cell types, to maintain homeostasis following injury. Adherens and tight junctions between cells maintain the epithelial barrier function and regulate the movement of molecules across it. In this review we discuss how abnormal epithelial structure and function, caused by chronic injury and abnormal repair, drives airway disease and specifically asthma and chronic obstructive pulmonary disease (COPD). In both diseases, inhaled allergens, pollutants and microbes disrupt junctional complexes and promote cell death, impairing the barrier function and leading to increased penetration of pathogens and a constant airway immune response. In asthma, the inflammatory response precipitates the epithelial injury and drives abnormal basal cell differentiation. This leads to reduced ciliated cells, goblet cell hyperplasia and increased epithelial mesenchymal transition, which contribute to impaired mucociliary clearance and airway remodelling. In COPD, chronic oxidative stress and inflammation trigger premature epithelial cell senescence, which contributes to loss of epithelial integrity and airway inflammation and remodelling. Increased numbers of basal cells showing deregulated differentiation, contributes to ciliary dysfunction and mucous hyperproduction in COPD airways. Defective antioxidant, antiviral and damage repair mechanisms, possibly due to genetic or epigenetic factors, may confer susceptibility to airway epithelial dysfunction in these diseases. The current evidence suggests that a constant cycle of injury and abnormal repair of the epithelium drives chronic airway inflammation and remodelling in asthma and COPD. Mechanistic understanding of injury susceptibility and damage response may lead to improved therapies for these diseases.

Phytochemistry and pharmacology of Armeniacae semen Amarum: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Armeniacae Semen Amarum (Prunus armeniaca L. var. ansu Maxim., Ku xingren, bitter almond, ASA) is an important medicine in Traditional Chinese Medicine (TCM). It is widely used because of its remarkable curative effect in relieving cough and asthma, moistening intestines and defecating.

AIM OF THE REVIEW

This review aims to enlighten the deeper knowledge about ASA, giving a comprehensive overview of its traditional uses, phytochemistry, pharmacology and toxicology for future investigation of plant-based drugs and therapeutic applications.

MATERIALS AND METHODS

The databases used are Web of Science, PubMed, Baidu academic, Google academic, CNKI, Wanfang and VIP . In addition, detailed information on ASA was obtained from relevant monographs such as Chinese Pharmacopoeia.

RESULTS

The active components of ASA mainly include amygdalin, bitter almond oil, essential oil, protein, vitamin, trace elements and carbohydrates. The pharmacological studies have shown that ASA has beneficial effects such as antitussive, antiasthmatic, anti-inflammatory, analgesic, antioxidant, antitumour, cardioprotective, antifibrotic, immune regulatory, bowel relaxation, insecticidal, etc. CONCLUSIONS: Many reports have been published on ASA's various active ingredients and biological uses. However, only a few reviews on its phytoconstituents and pharmacological uses. In addition, the exploration and development of ASA in other fields also deserve more attention in future research.

Emerging Roles of Non-Coding RNAs in Childhood Asthma

Asthma is a chronic airway inflammatory disease in children characterized by airway inflammation, airway hyperresponsiveness and airway remodeling. Childhood asthma is usually associated with allergy and atopy, unlike adult asthma, which is commonly associated with obesity, smoking, etc. The pathogenesis and diagnosis of childhood asthma also remains more challenging than adult asthma, such as many diseases showing similar symptoms may coexist and be confused with asthma. In terms of the treatment, although most childhood asthma can potentially be self-managed and controlled with drugs, approximately 5-10% of children suffer from severe uncontrolled asthma, which carries significant health and socioeconomic burdens. Therefore, it is necessary to explore the pathogenesis of childhood asthma from a new perspective. Studies have revealed that non-coding RNAs (ncRNAs) are involved in the regulation of respiratory diseases. In addition, altered expression of ncRNAs in blood, and in condensate of sputum or exhalation affects the progression of asthma via regulating immune response. In this review, we outline the regulation and pathogenesis of asthma and summarize the role of ncRNAs in childhood asthma. We also hold promise that ncRNAs may be used for the development of biomarkers and support a new therapeutic strategy for childhood asthma.

House dust mite-derived allergens effect on matrix metalloproteases in airway epithelial cells

Aim of the Study: Many allergens have protease activities. Although the immunomodulatory effects of these antigens are well known, the effects attributed to their protease activities are not thoroughly investigated. We set out to determine the effects of house dust mite (HDM) allergens with varying protease activities on bronchial epithelial cell functions. Materials and methods: BEAS-2B cells were maintained in ALI-culture and stimulated with Der p1 (cysteine protease), Der p6 (serine protease), and Der p2 (non-protease) with and without specific protease inhibitors or heat denaturation. Cell viability and epithelial permeability were measured with MTT and paracellular flux assay, respectively. The effect of heat denaturation on allergen structure was examined using in silico models. Matrix metalloproteinases (MMPs) were investigated at the transcription (qPCR), protein (ELISA), and functional (zymography) levels. Results: Epithelial permeability increased only after Der p6 but not after Der p1 or Der p2 stimulation. Der p2 increased both MMP-2 and MMP-9 expression, while Der p1 increased only MMP-9 expression. The heat-denatured form of Der p1 unexpectedly increased MMP-9 gene expression, which, through the use of in silico models, was attributed to its ability to change receptor connections by the formation of new electrostatic and hydrogen bonds. IL-8 and GM-CSF production were increased after Der p1 and Der p2 but decreased after Der p6 stimulation. IL-6 decreased after Der p1 but increased following stimulation with Der p6 and heat-denatured Der p2. Conclusion: Allergens in house dust mites are capable of inducing various changes in the epithelial cell functions by virtue of their protease activities.

Cord blood soluble Fas ligand linked to allergic rhinitis and lung function in seven-year-old children

BACKGROUND

Serum or cord blood soluble Fas ligand (FasL) has been related to asthma, allergic rhinitis, and atopic dermatitis in cross-sectional and short-term follow-up studies. However, the association of cord blood soluble FasL with long-term allergic outcomes has seldom been investigated.

METHODS

The Prediction of Allergies in Taiwanese Children birth cohort study recruited healthy newborns upon delivery. At birth, blood was collected from the umbilical cords of these children, and the cord blood soluble Fas ligand levels were measured. At the age of seven years, the allergic outcome of each child was diagnosed by pediatric allergists and pulmonologists. Tests were conducted to measure the specific immunoglobulin E, fractional exhaled nitric oxide (FeNO), and pulmonary function levels of each child.

RESULTS

Cord blood soluble FasL levels were higher in seven-year-old children with allergic rhinitis (Odds ratio [OR] = 2.41, p = 0.012) and expiratory airway obstruction (the highest forced expiratory volume in 1 second/forced vital capacity < 90%, OR = 2.11, p = 0.022). The FeNO and Dermatophagoides pteronyssinus-specific immunoglobulin E levels of seven-year-old children were positively correlated with cord blood soluble FasL levels (p = 0.006 and 0.02, respectively).

CONCLUSION

In this birth cohort, the cord blood soluble FasL levels were associated with allergic rhinitis, obstructive-type lung function, FeNO, and house dust mite sensitization in 7-year-old children. The cord blood soluble FasL level might be used as a predictor for allergic diseases in children who are 7 years old.

Herb pair of Ephedrae Herba-Armeniacae Semen Amarum alleviates airway injury in asthmatic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Ephedrae Herba (EH, Ephedra sinica Stapf.) and Armeniacae Semen Amarum (ASA, Prunus armeniaca L. var. ansu Maxim.) have been used to treat asthma, cold, fever, and cough in China for thousands of years.

AIM OF THE STUDY

In this study, we aimed to investigate the optimal ratio of EH and ASA compatibility (EAC) to reduce airway injury in asthmatic rats and its possible mechanism.

METHODS

Rats were sensitized with a mixture of acetylcholine chloride and histamine bisphosphate 1 h before sensitization by intragastric administration of EAC or dexamethasone or saline for 7 days. Subsequently, the ultrastructure of rat airway epithelial tissue changes, apoptosis of the airway epithelial cells, and the expression of mRNA and protein of EGRF and Bcl-2 were detected.

RESULTS

Transmission electron microscope: EAC (groups C and E) had the most prominent effect on repairing airway epithelial cells' ultrastructural changes in asthmatic rats. TUNEL: dexamethasone and EAC (groups B、C、E and F) inhibited the apoptosis of airway epithelial cells in asthmatic rats (P < 0.05). In situ hybridization: EAC (group E) inhibited the overexpression of EGFR and Bcl-2 mRNA (P < 0.05).Western Blotting: EAC (groups A、B、C、E and F) inhibited the upregulation of airway epithelial EGFR and Bcl-2 protein expression (P < 0.01).

CONCLUSIONS

Our findings indicate that EAC can inhibit abnormal changes in airway epithelial structure and apoptosis of airway epithelial cells, thereby alleviating airway injury. In this study, the best combination of EH and ASA to alleviate airway epithelial injury in asthmatic rats was group E (EH: ASA = 8: 4.5).

MiR-20a-5p suppressed TGF-β1-triggered apoptosis of human bronchial epithelial BEAS-2B cells by targeting STAT3

Apoptosis of bronchial epithelial cells contributes to lung diseases, including asthma. Although miR-20a-5p is reportedly downregulated in the bronchial epithelia of asthmatic patients, its function and mechanism still need to be explored. Here, we explored how miR-20a-5p affects human bronchial epithelial cells stimulated with transforming growth factor (TGF)-β₁. Using qRT-PCR, we observed downregulated miR-20a-5p levels in these cells. After transfecting miR-20a-5p mimics or inhibitors into human bronchial epithelium BEAS-2B cells, a Cell Counting Kit-8 assay and flow cytometry analysis showed that the mimics mitigated suppression of cell viability and acceleration of apoptosis that was triggered by TGF-β₁, whereas the inhibitors exerted the opposite effects. TGF-β₁ induced a decrease in expression of Bcl-2 and an increase in expression of Bax, both of which were inhibited by miR-20a-5p mimics and further enhanced by miR-20a-5p inhibitors. Further study verified that miR-20a-5p targeted the signal transducer and activator of transcription 3 (STAT3) and the STAT3 level was inversely related to the miR-20a-5p level. Furthermore, STAT3 overexpression partly counteracted the miR-20a-5p-induced anti-apoptotic effect in TGF-β1-treated BEAS-2B cells. In summary, this study suggested that miR-20a-5p restrained apoptosis in TGF-β1-stimulated BEAS-2B cells by targeting STAT3. MiR-20a-5p thus may be a novel therapeutic target for asthma treatment.

Ursolic Acid Protected Lung of Rats From Damage Induced by Cigarette Smoke Extract

Background: We found previously that ursolic acid (UA) administration could alleviate cigarette smoke-induced emphysema in rats partly through the unfolded protein response (UPR) PERK-CHOP and Nrf2 pathways, thus alleviating endoplasmic reticulum stress (ERS)-associated oxidative stress and cell apoptosis. We hypothesized that other UPR pathways may play similar roles in cigarette smoke extract (CSE)-induced emphysema. So, we sought to investigate the dynamic changes and effects of UPR and the downstream apoptotic pathways. Further, we investigated whether UA could alleviate CSE-induced emphysema and airway remodelling in rats, whether and when it exerts its effects through UPR pathways as well as Smads pathways.

Methods: One hundred eight Sprague Dawley (SD) rats were randomly divided into three groups: Sham group, CSE group, and UA group, and each group was further divided into three subgroups, administered CSE (vehicle) for 2, 3, or 4 weeks; each subgroup had 12 rats. We examined pathological changes, analyzed the three UPR signaling pathways and subsequent ERS, intrinsic and extrinsic apoptotic pathway indicators, as well as activation of Smad2,3 molecules in rat lungs.

Results: Exposure to CSE for 3 or 4 weeks could apparently induce emphysema and airway remodeling in rats, including gross and microscopic changes, alteration of mean alveolar number (MAN), mean linear intercept (MLI), and mean airway thickness in lung tissue sections. UA intervention could significantly alleviate CSE-induced emphysema and airway remodeling in rats. UA exerted its effects through ameliorating apoptosis by down regulating UPR signalling pathways and subsequent apoptosis pathways, as well as, downregulating p-Smad2 and p-Smad3 molecules.

Conclusions: UA attenuated CSE-induced emphysema and airway remodeling, exerting its effects partly through regulation of three UPR pathways, amelioration downstream apoptotic pathways, and alleviating activation of Smad2 and Smad3.

Bergapten induces G1 arrest of non‑small cell lung cancer cells, associated with the p53‑mediated cascade

The principal subtype of lung cancer, non‑small cell lung cancer (NSCLC) is a life‑threatening malignancy that causes high mortality rates. Bergapten (5‑methoxypsoralen) has been identified to possess anticancer activity against a number of carcinomas. In the present study, the effects of bergapten on NSCLC cells were investigated. The cell viability was determined by MTT assay. Cell cycle distribution was analyzed using flow cytometry. Protein expression and kinase cascade were demonstrated using western blot analysis. The results demonstrated that treatment with bergapten (50 µM for 48 h) inhibited the viability of A549 and NCI‑H460 NSCLC cells to 79.1±2.8% and 74.5±3.1%, respectively, compared with the controls. It was identified that bergapten induced G1 phase accumulation in A549 and NCI‑H460 cells between ~58 and 75% (P<0.01). In addition, bergapten significantly increased the sub‑G1 phase ratio to ~9% (P<0.05) in the two cell types. Further investigation demonstrated that bergapten upregulated the expression of cellular tumor antigen p53 (p53) and its downstream proteins cyclin‑dependent kinase inhibitor 1 and cyclin‑dependent kinase inhibitor 1B, whereas, it downregulated the expression of cyclin D1 and CDK4. Overall, these results suggested that bergapten may inhibit cell viability and trigger G1 arrest and apoptosis in A549 and NCI‑H460 cells, which may be attributed to the activation of p53‑mediated cascades. Therefore, bergapten may be beneficial for NSCLC treatment.

miR-155 Modulates Cockroach Allergen- and Oxidative Stress-Induced Cyclooxygenase-2 in Asthma

Exposure to cockroach allergen is a strong risk factor for developing asthma. Asthma has been associated with allergen-induced airway epithelial damage and heightened oxidant stress. In this study, we investigated cockroach allergen-induced oxidative stress in airway epithelium and its underlying mechanisms. We found that cockroach extract (CRE) could induce reactive oxygen species (ROS) production, particularly mitochondrial-derived ROS, in human bronchial epithelial cells. We then used the RT² Profiler PCR array and identified that cyclooxygenase-2 (COX-2) was the most significantly upregulated gene related to CRE-induced oxidative stress. miR-155, predicted to target COX-2, was increased in CRE-treated human bronchial epithelial cells, and was showed to regulate COX-2 expression. Moreover, miR-155 can bind COX-2, induce COX-2 reporter activity, and maintain mRNA stability. Furthermore, CRE-treated miR-155^-/- mice showed reduced levels of ROS and COX-2 expression in lung tissues and PGE₂ in bronchoalveolar lavage fluid compared with wild-type mice. These miR-155^-/- mice also showed reduced lung inflammation and Th2/Th17 cytokines. In contrast, when miR-155^-/- mice were transfected with adeno-associated virus carrying miR-155, the phenotypic changes in CRE-treated miR-155^-/- mice were remarkably reversed, including ROS, COX-2 expression, lung inflammation, and Th2/Th17 cytokines. Importantly, plasma miR-155 levels were elevated in severe asthmatics when compared with nonasthmatics or mild-to-moderate asthmatics. These increased plasma miR-155 levels were also observed in asthmatics with cockroach allergy compared with those without cockroach allergy. Collectively, these findings suggest that COX-2 is a major gene related to cockroach allergen-induced oxidative stress and highlight a novel role of miR-155 in regulating the ROS-COX-2 axis in asthma.

PI3K, p38 and JAK/STAT signalling in bronchial tissue from patients with asthma following allergen challenge

Background

Inhaled allergen challenges are often used to evaluate novel asthma treatments in early phase clinical trials. Current novel therapeutic targets in asthma include phosphoinositide 3-kinases (PI3K) delta and gamma, p38 mitogen-activated protein kinase (p38) and Janus kinase/Signal Transducer and Activator of Transcription (JAK/STAT) signalling pathways. The activation of these pathways following allergen exposure in atopic asthma patients it is not known.

Methods

We collected bronchial biopsies from 11 atopic asthma patients at baseline and after allergen challenge to investigate biomarkers of PI3K, p38 MAPK and JAK/STAT activation by immunohistochemistry. Cell counts and levels of eosinophil cationic protein and interleukin-5 were also assessed in sputum and bronchoalvelar lavage.

Results

Biopsies collected post-allergen had an increased percentage of epithelial cells expressing phospho-p38 (17.5 vs 25.6%, p = 0.04), and increased numbers of sub-epithelial cells expressing phospho-STAT5 (122.2 vs 540.6 cells/mm², p = 0.01) and the PI3K marker phospho-ribosomal protein S6 (180.7 vs 777.3 cells/mm^2,p = 0.005). Type 2 inflammation was increased in the airways post allergen, with elevated levels of eosinophils, interleukin-5 and eosinophil cationic protein.

Conclusions

Future clinical trials of novel kinase inhibitors could use the allergen challenge model in proof of concept studies, while employing these biomarkers to investigate pharmacological inhibition in the lungs.

Gallic acid induces G1 phase arrest and apoptosis of triple-negative breast cancer cell MDA-MB-231 via p38 mitogen-activated protein kinase/p21/p27 axis

Gallic acid (GA) possesses potential antitumoral activity on different types of malignancies. In this study, we aimed to explore the antitumoral effects of GA on triple-negative breast cancer (TNBC) cells, the breast cancer cells showing resistance to hormonal therapy or HER2 receptor targeting therapy. We observed that GA treatment significantly decreased the cell viability of human TNBC cell line MDA-MB-231 and HS578T in a dose-dependent manner. In addition, GA exerted a relative lower cytotoxicity on noncancer breast fibroblast MCF-10F. Next, we analyzed the changes of cell-cycle distribution in response to GA treatment and found that GA led to an increase of G0/G1 and sub-G1 phase ratio in MDA-MB-231 cells. We further explored the crucial mediators controlling cell cycle and inducing apoptotic signaling, and the findings showed that GA downregulated cyclin D1/CDK4 and cyclin E/CDK2, upregulated p21and p27, and induced activation of caspase-9 and caspase-3. In addition, we demonstrated that p38 mitogen-activated protein kinase was involved in the GA-mediated cell-cycle arrest and apoptosis. Collectively, our findings indicate that GA inhibits the cell viability of TNBC cells, which may attribute to the G1 phase arrest and cellular apoptosis via p38 mitogen-activated protein kinase/p21/p27 axis. Thus, we suggest that GA could be beneficial to TNBC treatment.

Aeroallergen Der p 2 promotes motility of human non-small cell lung cancer cells via toll-like receptor-mediated up-regulation of urokinase-type plasminogen activator and integrin/focal adhesion kinase signaling

House dust mite (HDM) allergens are one of the major causes leading to respiratory hypersensitiveness and airway remodeling. Here we hypothesized that a major HDM allergen Der p 2 could increase cell motility and invasiveness of non-small cell lung cancer (NSCLC) cells. Our results showed that low dose (1 and 3 μg/mL) recombinant Der p 2 protein (DP2) enhanced the migration and invasiveness of human NSCLC cell A549, H1299 and CL1-5, but nonsignificantly altered their growth. Further investigation revealed that integrin αV level was increased and its downstream signaling including focal adhesion kinase (FAK) and paxillin were activated in A549 cells exposed to DP2. In parallel, DP2 also activated the FAK-associated signaling effectors such as Src, phosphatidyl inositol 3-kinase (PI3K), AKT, p38 mitogen-activated protein kinase (P38), extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK). Our findings also revealed that DP2 increased expression level of urokinase type plasminogen-activated kinase (uPA) and uPA receptor (uPAR), and subsequently enhanced the binding of uPAR to integrin αV. Moreover, the involvement of toll-like receptor 2/4 (TLR2/4)-triggered ERK1/2 activation in the increased expression of uPA and uPAR was also demonstrated. Collectively, these findings indicate that DP2 can enhance cell motility and invasiveness of NSCLC cells, attributing to TLR2/4-ERK1/2 activation, increased uPA and uPAR expression, enhanced binding of uPAR to integrin αV, and the consequent FAK signaling cascades. Thus, we suggest that DP2 may exacerbate NSCLC via promoting metastatic ability of carcinoma cell.