Propofol Attenuates Airway Inflammation in a Mast Cell-Dependent Mouse Model of Allergic Asthma by Inhibiting the Toll-like Receptor 4/Reactive Oxygen Species/Nuclear Factor κB Signaling Pathway

Immunomodulatory effect of glabridin in ovalbumin induced allergic asthma and its comparison with methylprednisolone in a preclinical rodent model

Glabridin, a polyphenolic flavonoid derived from Glycyrrhiza glabra (licorice) roots, has shown anti-inflammatory and antioxidant properties. The current study sought to investigate glabridin's immunomodulatory effect in ovalbumin induced allergic asthma. Healthy male Wistar rats were divided into five groups. Group I served as a control group. Asthma was induced in groups II- IV. Groups III and IV were treated with glabridin (40 mg/kg) and methylprednisolone (15 mg/kg), respectively. Inflammatory cells counts were determined in blood and bronchoalveolar lavage fluid (BALF). Serum IgE levels and levels of catalase, superoxide dismutase and glutathione peroxidase in lung homogenate were measured. The levels of mRNA expression of pro-inflammatory, anti-inflammatory and oxidative stress markers were analysed. Delayed type hypersensitivity (DTH) and acute toxicity of glabridin were also checked. Glabridin significantly decreased inflammatory cells in the blood and BALF. It increased the concentration of antioxidant enzymes catalase, superoxide dismutase and glutathione peroxidase. Glabridin markedly decreased serum IgE levels and DTH when compared to asthmatic rats. It significantly alleviated the expression of TNF-α, IL-4, IL-5, CXCL1, iNOS, and NF-κB. Administering 10 times the therapeutic dose of glabridin did not show any signs of acute toxicity. Findings suggest that glabridin has the potential to ameliorate allergic asthma and its effects are comparable to those of methylprednisolone. The immunomodulatory effect of glabridin might be contributed by the suppression of pro-inflammatory cytokines, oxidative stress markers, IgE antibodies, and elevation of antioxidant enzymes, suggesting future study and clinical trials to propose it as a candidate to treat allergic asthma.

Electroacupuncture-induced activation of GABAergic system alleviates airway inflammation in asthma model by suppressing TLR4/MyD88/NF-κB signaling pathway

BACKGROUND

Electroacupuncture (EA) has been shown to attenuate airway inflammation in asthmatic mice; however, the underlying mechanism is not fully understood. Studies have shown that EA can significantly increase the inhibitory neurotransmitter γ-aminobutyric acid (GABA) content in mice, and can also increase the expression level of GABA type A receptor (GABAAR). Furthermore, activating GABAAR may relieve inflammation in asthma by suppressing toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)/nuclear factor-kappa B (NF-κB) signaling pathway. Therefore, this study aimed to investigate the role of GABAergic system and TLR4/MyD88/NF-κB signaling pathway in asthmatic mice treated with EA.

METHODS

A mouse model of asthma was established, and a series of methods including Western blot and histological staining assessment were employed to detect the level of GABA, and expressions of GABAAR and TLR4/MyD88/NF-κB in lung tissue. In addition, GABAAR antagonist was used to further validate the role and mechanism of GABAergic system in mediating the therapeutic effect of EA in asthma.

RESULTS

The mouse model of asthma was established successfully, and EA was verified to alleviate airway inflammation in asthmatic mice. The release of GABA and the expression of GABAAR were significantly increased in asthmatic mice treated with EA compared with untreated asthmatic mice ( P  < 0.01), and the TLR4/MyD88/NF-κB signaling pathway was down-regulated. Moreover, inhibition of GABAAR attenuated the beneficial effects of EA in asthma, including the regulation of airway resistance and inflammation, as well as the inhibitory effects on TLR4/MyD88/NF-κB signaling pathway.

CONCLUSION

Our findings suggest that GABAergic system may be involved in mediating the therapeutic effect of EA in asthma, possibly by suppressing the TLR4/MyD88/NF-κB signaling pathway.

Effect of General Anesthesia Maintenance with Propofol or Sevoflurane on Fractional Exhaled Nitric Oxide and Eosinophil Blood Count: A Prospective, Single Blind, Randomized, Clinical Study on Patients Undergoing Thyroidectomy

Background: Nitric oxide (NO) is considered a means of detecting airway hyperresponsiveness, since even non-asthmatic patients experiencing bronchospasm intraoperatively or postoperatively display higher levels of exhaled NO. It can also be used as a non-invasive biomarker of lung inflammation and injury. This prospective, single-blind, randomized study aimed to evaluate the impact of two different anesthesia maintenance techniques on fractional exhaled nitric oxide (FeΝO) in patients without respiratory disease undergoing total thyroidectomy under general anesthesia. Methods: Sixty patients without respiratory disease, atopy or known allergies undergoing total thyroidectomy were randomly allocated to receive either inhalational anesthesia maintenance with sevoflurane at a concentration that maintained Bispectral Index (BIS) values between 40 and 50 intraoperatively or intravenous anesthesia maintenance with propofol 1% targeting the same BIS values. FeΝO was measured immediately preoperatively (baseline), postoperatively in the Postanesthesia Care Unit and at 24 h post-extubation with a portable device. Other variables measured were eosinophil blood count preoperatively and postoperatively and respiratory parameters intraoperatively. Results: Patients in both groups presented lower than baseline values of FeΝO measurements postoperatively, which returned to baseline measurements at 24 h post-extubation. In the peripheral blood, a decrease in the percentage of eosinophils was demonstrated, which was significant only in the propofol group. Respiratory lung mechanics were better maintained in the propofol group as compared to the sevoflurane group. None of the patients suffered intraoperative bronchospasm. Conclusions: Both propofol and sevoflurane lead to the temporary inhibition of NO exhalation. They also seem to attenuate systemic hypersensitivity response by reducing the eosinophil count in the peripheral blood, with propofol displaying a more pronounced effect and ensuring a more favorable mechanical ventilation profile as compared to sevoflurane. The attenuation of NO exhalation by both agents may be one of the underlying mechanisms in the reduction in airway hyperreactivity. The clinical significance of this fluctuation remains to be studied in patients with respiratory disease.

Propofol pretreatment alleviates mast cell degranulation by inhibiting SOC to protect the myocardium from ischemia-reperfusion injury

Propofol (PPF) has a protective effect on myocardial ischemia-reperfusion (I/R) injury (MIRI). The purpose of this study was to investigate whether the myocardial protective effect of propofol is related to the inhibition of mast cell degranulation and explore the possible mechanisms involved. Our in vivo results showed that compared with the sham group, cardiac function, infarct size, histopathological damage, apoptosis, and markers of myocardial necrosis were significantly increased in the ischemia-reperfusion group, and propofol pretreatment alleviated these effects. In the coculture system, propofol-treated mast cells reduced their tryptase activity, resulting in cardiomyocyte protective effects, such as decreased apoptosis of cardiomyocytes and decreased expression of myocardial necrosis markers. Finally, experimental results in vitro revealed that thapsigargin (TG) can increase mast cell degranulation, tryptase release, calcium ion concentration, and the expression of STIM1 and Orai1 induced by H/R, but propofol pretreatment can partially reverse the above effects. These results suggested that the cardioprotective effect of propofol is achieved in part by inhibiting calcium influx through store-operated Ca²⁺ channels (SOCs) and thus alleviating mast cell degranulation.

MicroRNA-885-3p alleviates bronchial epithelial cell injury induced by lipopolysaccharide via toll-like receptor 4

Airway inflammation is one of the typical pathological characteristics of asthma. MicroRNAs (miRNAs) play important roles in regulating inflammation. Nevertheless, miRNA-885-3p (miR-885-3p)’s role in asthmatic inflammation and the underlying mechanism need to be explained. In this work, miR-885-3p expression and toll-like receptor 4 (TLR4) expression in asthma patients’ plasma and lipopolysaccharide (LPS)-treated 16HBE cells were detected through quantitative real-time PCR. The interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels in 16HBE cell supernatant were examined via enzyme-linked immunosorbent assay. Cell counting kit-8 (CCK-8) assay and flow cytometry were employed to examine 16HBE cell viability and apoptosis, respectively. Western blotting was performed to examine the expression of TLR4, cleaved caspase-3, B-cell lymphoma-2 (Bcl-2), nuclear factor-kappa B (NF-κB) p65, Bcl-2-related X protein (Bax), phosphorylated (p)-NF-κB p65 and myeloid differentiation primitive-response protein 88 (MyD88) in 16HBE cells. Furthermore, the targeted relationship between TLR4 and miR-885-3p in 16HBE cells was determined through dual-luciferase reporter gene assay. Compared with healthy volunteers, miR-885-3p expression in acute asthma patients’ plasma was significantly downregulated. In 16HBE cells, the stimulation of LPS reduced miR-885-3p expression. MiR-885-3p overexpression reduced LPS-stimulated 16HBE cell injury by enhancing cell viability, and suppressing the levels of inflammatory factors and apoptosis. Furthermore, TLR4 was identified as miR-885-3p’s target gene. TLR4 overexpression weakened the impacts of miR-885-3p on LPS-stimulated cell injury and NF-κB-MyD88 signaling. In conclusion, miR-885-3p can reduce LPS-induced 16HBE cell damage, via targeting TLR4 to suppress the NF-κB-MyD88 pathway.

18β-Glycyrrhetinic acid suppresses allergic airway inflammation through NF-κB and Nrf2/HO-1 signaling pathways in asthma mice

18β-Glycyrrhetinic acid (18β-GA), the main bioactive component of Glycyrrhizae Radix, is considered a promising anti-inflammatory and antioxidant agent. Here, we evaluated the anti-inflammatory and antioxidant effects of 18β-GA in an ovalbumin (OVA)-induced asthma mouse model, and examined the role of NF-κB and Nrf2/HO-1 signaling pathways. The histopathological changes of lung tissue in mouse were assessed by histochemical staining and counting of inflammatory cells. The levels of IgE and inflammatory cytokines in the bronchoalveolar lavage fluid of mice were detected by ELISA. In OVA-induced asthmatic mice, 18β-GA treatment can significantly improve lung function and reduce lung inflammation including infiltration of inflammatory cells. In addition, 18β-GA reduced the OVA-induced NF-κB phosphorylation in lungs of mice while increasing the expression of Nrf2 and HO-1. These results indicate that 18β-GA protects OVA-induced allergic inflammation of airway by inhibiting phosphorylation of NF-κB and enhancing the Nrf2/HO-1 pathway, and serves as a potential treatment option for allergic inflammation of airway.

Cytokine-Induced JAK2-STAT3 Activates Tissue Regeneration under Systemic or Local Inflammation

We investigated the immune response mechanisms under systemic and local inflammation using mouse models whereby lipopolysaccharide (LPS) was administered intraperitoneally to induce systemic inflammation, and epicutaneous sensitization with ovalbumin was used to induce local inflammation. LPS increased the immune cell infiltration in the cardiac muscle near the aorta, alveoli, hepatic sinusoid, renal interstitium, and the submucosal layer of the duodenum. Similarly, ovalbumin increased the abundance of macrophages in the skin. Both LPS and ovalbumin induced NF-κB p65 and IκBα phosphorylation, as well as the expression of NF-κB target genes (TLR4, IL6, and TNFα). Additionally, both LPS and ovalbumin led to an increase in the absolute IL-1β, IL-6, and TNFα serum levels and cytokine-related janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) phosphorylation. Moreover, the activated JAK2/STAT3 signaling increased the number of Ki67-positive cells (proliferating cells) and development pathway target gene expression (regeneration) in the inflammation models. In conclusion, LPS and ovalbumin increase immune cell infiltration in tissues, NF-κB activation, cytokine levels in serum, cytokine-stimulated JAK2/STAT3 signaling, and tissue regeneration.

Propofol ameliorates ischemic brain injury by blocking TLR4 pathway in mice

Ischemic brain injury is one of the most serious perioperative complications. However, effective preventative methods have not yet been established. This study aimed to investigate whether propofol has neuroprotective effects against ischemic brain injury, with a specific focus on Toll-like receptor 4 (TLR4). Focal brain ischemia was induced via a combination of left common carotid artery occlusion and distal left middle cerebral artery coagulation in mice. Either propofol (10 mg/kg) or vehicle was intravenously injected 10 min prior to the induction of brain ischemia in wild-type and TLR4 knockout mice. Infarct volume, pro-inflammatory cytokine expression, inflammatory cell infiltration, and neurobehavioral function were assessed. Propofol administration significantly reduced infarct volume in wild-type mice (26.9 ± 2.7 vs 15.7 ± 2.0 mm³ at day 7), but not in TLR4 knockout mice. Compared with the control mice, the propofol-treated wild-type mice exhibited lower levels of IL-6 (0.57 ± 0.23 vs 1.00 ± 0.39 at 24 h), and smaller numbers of TLR4-expressing microglia in the penumbra (11.7 ± 3.1 vs 25.1 ± 4.7 cells/0.1 mm²). In conclusion, propofol administration prior to ischemic brain insult attenuated brain injury by blocking the TLR4-dependent pathway and suppressing pro-inflammatory cytokine production.

Effect of Theaflavin on Inflammatory and Remolding of Airway in the Asthma Mice

To study the effect of theaflavin on the airway’s inflammation and remodeling in mice with asthma. The mice were divided into the control, asthma model, and the theaflavin treatment groups to analyze the changes in pulmonary compliance and lung resistance of the mice with asthma to theaflavin treatment. The theaflavin treatment groups consisted of the low-dose (15 mg/kg theaflavin-intragastric administration), medium-dose (30 mg/kg), and high-dose (60 mg/kg) groups. Alveoli lavage liquid was gathered from the mice to count the number of inflammatory cells, and the levels of interleukin 4 (IL-4), interleukin 5 (IL-5), interleukin 13 (IL-13), and eotaxin were detected by ELISA. The levels of proteins, such as transforming growth factor-1 (TGF-1), alpha-smooth muscle actin (α-SMA), CyclinD1,CyclinD2, Toll-like receptors-4 (TLR4), myeloid differentiation factor 88 (MyD88), and NF-κBp65, which showed the performance of lung tissue was tested by Western blotting. Compared to the control group, the lung resistance of the asthma model mice was increased, and compliance was decreased after increasing concentrations of acetylcholine (Mch) stimulation. Compared to the asthma model group, the pulmonary resistance was decreased, and pulmonar compliance was increased according to the rising concentration of Mch in theaflavin-L, theaflavin-M and theaflavin-H mice. Compared to the control group, the number of cells, macrophages, acidophilic cells, lymph, and neutrophile granulocytes increased in the alveolar perfusion fluid of asthmatic mice. The level of interleukin 4, interleukin 5, interleukin 13, and eotaxin, TGF-β1, α-SMA, Cyclin D1, MyD88, TLR4, Cyclin D2, and NF-κBp65 proteins of the lung was also increased. Compared to the model group, the number of cells, macrophages, acidophilic cells, lymph, and neutrophile granulocytes were decreased successively in the alveolar lavage fluid in the theaflavin-L, theaflavin-M, and theaflavin-H mice. Meanwhile, the content of interleukin 4, interleukin 5, interleukin 13, and eotaxin were decreased successively, and the level of TGF-β1, α-SMA, Cyclin D1, MyD88, TLR4, Cyclin D2, and NF-κBp65 protein increased successively in the theaflavin-L, theaflavin-M, and theaflavin-H mice. Theaflavin has been found to reduce airway inflammation, impede airway remodeling, and decrease the TLR 4/MyD88/NF-κB signaling in asthmatic mice.

Edaravone alleviated propofol-induced neural injury in developing rats by BDNF/TrkB pathway

As a variety of free radical scavenger, edaravone has shown its potential in producing antioxidant, anti-inflammatory and neuroprotective effects in various disease models. However, the underlying mechanism behind the neuroprotective effects of edaravone remained unclear. This study is aimed at determining the effects of edaravone on neuroprotection and anti-inflammatory through a propofol-induced neural injury rat model. Firstly, an observation was made of apoptosis and neuroinflammation in the hippocampus of developing under the influence of propofol. It was found out that propofol could produce inflammatory effects in the hippocampus by enhancing the astrogliosis (GFAP) activation and elevating the level of neuronal nitric oxide synthase (nNOS), pro-inflammatory cytokines interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α). Meanwhile, the increase of apoptosis cells and the decrease of neurons (NeuN) were speculated to aggravate neural injury. Furthermore, it was demonstrated that edaravone intervention can reverse the neural apoptosis and inflammation. Additionally, the intraperitoneal injection of edaravone, the intraperitoneal injection of the brain-derived neurotrophic factor (BDNF)-mimicking small compound (7,8 dihydroxyflavone) and the intracranial injection of the exogenous BDNF were all respectively effective in alleviating the propofol-induced neural apoptosis and inflammation in the hippocampus. It was also found out that edaravone-activated downstream signalling through tyrosine kinase receptor B (TrkB) receptors in astrocyte, microglia and neuron. However, the neural injury of propofol had no impact on long-term learning and memory, except causing a short-term neurotoxicity. In conclusion, edaravone could alleviate the propofol-induced neural injury in developing rats through BDNF/TrkB pathway.

Therapeutic effects and mechanisms study of Hanchuan Zupa Granule in a Guinea pig model of cough variant asthma

ETHNOPHARMACOLOGICAL RELEVANCE

Hanchuan Zupa Granule (HCZP), a traditional Chinese ethnodrug, has the functions of supressing a cough, resolving phlegm, warming the lungs, and relieving asthma. In clinical practice employing traditional Chinese medicine (TCM), HCZP is commonly used to treat acute colds, cough and abnormal mucous asthma caused by a cold, or "Nai-Zi-Lai" in the Uygur language. Studies have confirmed the use of HCZP to treat cough variant asthma (CVA) and other respiratory diseases. However, the pharmacological mechanisms of HCZP remain unrevealed.

AIM OF THE STUDY

To investigate the anti-tussive and anti-asthmatic effects and the possible pharmacological mechanisms of HCZP in the treatment of CVA.

MATERIALS AND METHODS

A guinea pig CVA animal model was established by intraperitoneal injection of ovalbumin (OVA) combined with intraperitoneal injection of aluminium hydroxide adjuvant and atomized OVA. Meanwhile, guinea pigs with CVA received oral HCZP (at dosages of 0.571, 0.285 and 0.143 g/kg bodyweight). The number of coughs induced by aerosol capsaicin was recorded, and the airway hyperresponsiveness (AHR) of CVA guinea pigs was detected with the FinePointe series RC system. H&E staining of lung tissues was performed to observe pathological changes. ELISA was used to detect inflammatory cytokines. qRT-PCR and western blotting analyses were used to detect the expression of Th1-specific transcription factor (T-bet), Th2-specific transcription factor (GATA3), and Toll-like receptor 4 (TLR4) signal transduction elements. These methods were performed to assess the protective effects and the potential mechanisms of HCZP on CVA.

RESULTS

Great changes were found in the CVA guinea pig model after HCZP treatment. The number of coughs induced by capsaicin in guinea pigs decreased, the body weights of guinea pigs increased, and inflammation of the eosinophilic airway and AHR were reduced simultaneously. These results indicate that HCZP has a significant protective effect on CVA. A pharmacological study of HCZP showed that the levels of interleukin-4 (IL-4) and IL-5 and tumour necrosis factor-α (TNF-α) in serum decreased. The amount of interferon-γ (IFN-γ) increased, mRNA and protein expression of TLR4 and GATA3 weakened, and mRNA and protein expression of T-bet increased.

CONCLUSIONS

HCZP ameliorated the symptoms of guinea pigs with CVA induced by OVA by regulating the Th1/Th2 imbalance and TLR4 receptors.

Identification of biomarkers in common chronic lung diseases by co-expression networks and drug-target interactions analysis

Background

asthma, chronic obstructive pulmonary disease (COPD), and idiopathic pulmonary fibrosis (IPF) are three serious pulmonary diseases that contain common and unique characteristics. Therefore, the identification of biomarkers that differentiate these diseases is of importance for preventing misdiagnosis. In this regard, the present study aimed to identify the disorders at the early stages, based on lung transcriptomics data and drug-target interactions.

Methods

To this end, the differentially expressed genes were found in each disease. Then, WGCNA was utilized to find specific and consensus gene modules among the three diseases. Finally, the disease-disease similarity was analyzed, followed by determining candidate drug-target interactions.

Results

The results confirmed that the asthma lung transcriptome was more similar to COPD than IPF. In addition, the biomarkers were found in each disease and thus were proposed for further clinical validations. These genes included RBM42, STX5, and TRIM41 in asthma, CYP27A1, GM2A, LGALS9, SPI1, and NLRC4 in COPD, ATF3, PPP1R15A, ZFP36, SOCS3, NAMPT, and GADD45B in IPF, LRRC48 and CETN2 in asthma-COPD, COL15A1, GIMAP6, and JAM2 in asthma-IPF and LMO7, TSPAN13, LAMA3, and ANXA3 in COPD-IPF. Finally, analyzing drug-target networks suggested anti-inflammatory candidate drugs for treating the above mentioned diseases.

Conclusion

In general, the results revealed the unique and common biomarkers among three chronic lung diseases. Eventually, some drugs were suggested for treatment purposes.

Saxagliptin mitigates airway inflammation in a mouse model of acute asthma via modulation of NF-kB and TLR4

Saxagliptin (Saxa), a dipeptidyl dipeptidase-4 (DPP-4) inhibitor, is widely used for the treatment of type 2 diabetes mellitus. It has been documented to have immunomodulatory and anti-inflammatory actions. Our objective was to delineate the protective effect and the underlying mechanism of Saxa-in comparison with Dexamethasone (Dexa) - in airway inflammation induced by ovalbumin (OVA) in mice.

METHODS

Mice were OVA-sensitized and challenged for the induction of acute asthma. Mice were orally administrated Saxa or Dexa. Total and differential cell counts, lactate dehydrogenase (LDH) and total protein concentrations were assessed in bronchoalveolar lavage fluid (BALF). The toll-like receptor 4 (TLR4), nuclear factor-kappa B (NF-kB), reduced glutathione (GSH), and total nitrate/nitrite products (NOx) levels as well as myeloperoxidase (MPO) activity in lung tissues were measured. Histopathological examination of the lung specimens was carried out using the hematoxylin and eosin (H & E) staining.

RESULTS

Histopathological examination revealed that both Saxa and Dexa ameliorated OVA-induced inflammatory changes and significantly reduced total and differential leukocyte counts, LDH and total protein level in BALF upon comparison with OVA group. In addition, both treatments significantly mitigated OVA-induced oxidative stress as evidenced by diminished lung NOx level and MPO activity and elevated GSH level. The elevation of TLR4 and NF-kB levels in lung tissue were ameliorated by Saxa and Dexa administration.

CONCLUSION

Saxa had marked antiasthmatic effect in OVA-induced allergic asthma through modulation of TLR4 and NF-κB signaling. Also, Saxa may represent a promising therapeutic agent for acute allergic asthma.

FcεRI-HDAC3-MCP1 Signaling Axis Promotes Passive Anaphylaxis Mediated by Cellular Interactions

Anaphylaxis is an acute and life-threatening systemic reaction. Food, drug, aero-allergen and insect sting are known to induce anaphylaxis. Mast cells and basophils are known to mediate Immunoglobulin E (IgE)-dependent anaphylaxis, while macrophages, neutrophils and basophils mediate non IgE-dependent anaphylaxis. Histone deacetylases (HDACs) play various roles in biological processes by deacetylating histones and non-histones proteins. HDAC inhibitors can increase the acetylation of target proteins and affect various inflammatory diseases such as cancers and allergic diseases. HDAC3, a class I HDAC, is known to act as epigenetic and transcriptional regulators. It has been shown that HDAC3 can interact with the high-affinity Immunoglobulin E receptor (FcεRI), to mediate passive anaphylaxis and cellular interactions during passive anaphylaxis. Effects of HDAC3 on anaphylaxis, cellular interactions involving mast cells and macrophages during anaphylaxis, and any tumorigenic potential of cancer cells enhanced by mast cells will be discussed in this review. Roles of microRNAs that form negative feedback loops with hallmarks of anaphylaxis such as HDAC3 in anaphylaxis and cellular interactions will also be discussed. The roles of MCP1 regulated by HDAC3 in cellular interactions during anaphylaxis are discussed. Roles of exosomes in cellular interactions mediated by HDAC3 during anaphylaxis are also discussed. Thus, review might provide clues for development of drugs targeting passive anaphylaxis.

Cucurbitacin E ameliorates lipopolysaccharide-evoked injury, inflammation and MUC5AC expression in bronchial epithelial cells by restraining the HMGB1-TLR4-NF-κB signaling

Asthma is a chronic inflammatory disorder of airway affecting people from childhood to old age, and is characterized by airway epithelial dysfunction. Cucurbitacin E (CuE), a tetracyclic triterpene isolated from Cucurbitaceae plants, has been recently proved to exert anti-inflammation and immunology regulation activities. Nevertheless, its roles in asthma remains poorly defined. In the current study, CuE had little cytotoxicity on cell viability of human bronchial epithelial cell line BEAS-2B. Moreover, lipopolysaccharide (LPS) exposure inhibited cell viability and induced cell apoptosis, which was reversed following CuE pretreatment. Additionally, CuE administration suppressed LPS-induced inflammatory cytokine production, including TNF-α, IL-6, and IL-8. Simultaneously, supplementation with CuE decreased the transcripts and releases of mucin 5AC (MUC5AC) in LPS-treated BEAS-2B cells. Intriguingly, CuE inhibited LPS-evoked activation of the high-mobility group box1 (HMGB1)-TLR4-NF-κB signaling by reducing the expression of HMGB1, TLR4 and p-p65 NF-κB. Notably, restoring this pathway by elevating HMGB1 expression largely offset the protective function of CuE against LPS-triggered cell injury, inflammatory response and MUC5AC expression. Consequently, these findings highlight that CuE can ameliorate human bronchial epithelial cell insult and inflammation under LPS-simulated asthmatic conditions by blocking the HMGB1-TLR4-NF-κB signaling, thereby supporting its usefulness as a promising therapeutic agent against asthma.

Expression of suppressor of cytokine signaling 3 (SOCS3) and interleukin-6 (-174-G/C) polymorphism in atopic conditions

Hypersensitivity of the immune system is caused by elevated immunoglobulin E (IgE) levels in the serum, in response to a discrete allergen leading to allergic reactions. IgE-mediated inflammation is regulated by the cascade of defense related signaling molecules including interleukin-6 (IL-6) that plays pivotal role in the survival and maturation of mast cells during an allergic reaction. IL-6 mediated defense responses are tightly regulated by Suppressor of Cytokine Signaling 3 (SOCS3), an inhibitory molecules of Janus Kinase-Signal Transducers and Activators of Transcription (JAK-STAT) signaling, in a negative feedback mechanism. The given study focuses on the assessment of crosstalk between SOCS3 and IL-6 to unravel the molecular significance of SOCS3 and IL-6 in the diagnosis and prognosis of allergy. The expression study of SOCS3 through real-time PCR analysis revealed, a 5.9 mean fold increase in SOCS3 expression in atopic cases in comparison to control cases. Moreover, IL-6 has, also, been found significantly enhanced in the serum level of atopic cases (26.4 pg/ml) as compared to control cases (3.686 pg/ml). Female population was found to be at a higher risk to develop atopic condition than male population as females exhibited higher expression of both SOCS3 and IL-6 than males. Furthermore, the polymorphic study of IL-6 promoter region (IL-6 174-G/C) in atopic population has reasserted the importance of SOCS3 and IL-6 in the diagnosis and prognosis of allergy. Expression of SOCS3 and IL-6 serum levels were found to be highly correlated. Therefore establishing the role of IL-6 (-174-G/C) polymorphism on the expression of SOCS3 and IL-6 in atopic cases. Notably, the study established SOCS3 and IL-6 as potential targets for the diagnosis/prognosis of allergy and for the development of reliable therapeutic strategies to control atopic conditions in the near future.

Oral feeding of Lactobacillus bulgaricus N45.10 inhibits the lung inflammation and airway remodeling in murine allergic asthma: Relevance to the Th1/Th2 cytokines and STAT6/T-bet

Asthma is a chronic disease with impacts on public health. It affects the airways causing pulmonary inflammation mediated by CD4 T cells type Th2, eosinophilia, mucus hypersecretion, and elevated IgE. The unbalance between cytokines and transcription factors is an important feature in asthma. Probiotics has gaining highlight as a therapy for chronic diseases. Thus, we investigate the Lactobacillus bulgaricus (Lb) effect in murine allergic asthma. BALB/c-mice were sensitized to ovalbumin (OA) on days 0 and 7 and were challenged from day 14-28 with OA. Mice received Lb seven days prior to sensitization and it was kept until day 28. The Lb attenuated the eosinophils infiltration, mucus and collagen secretion, IgE production, pro-inflammatory cytokines, TLR4 expression, GATA3, STAT6 and RORγt in lung. Otherwise, Lb increased the anti-inflammatory cytokines, the T-bet and foxp3. Finally, Lb attenuated the allergic asthma-induced inflammation and airway remodeling by interfering on Th1/Th2 cytokines and STAT6/T-bet transcription factors.