Intranasal Inhalation Research Articles

Assessment of the safety and anti-inflammatory effects of three Bacillus strains in the respiratory tract.

Chronic respiratory diseases are part of accumulating health problems partly due to worldwide increase in air pollution. By their antimicrobial and immunomodulatory properties, some probiotics constitute promising alternatives for the prevention and treatment of chronic respiratory diseases. We have isolated Bacillus strains from Korean fermented foods and selected three potentially probiotic strains (two Bacillus subtilis and one Bacillus amyloliquefaciens) based on safety, antimicrobial efficacy, activity against airborne pathogens and their immunomodulatory properties in vivo. Safety evaluation included in silico analysis for confirming absence of virulence genes. Safety for the respiratory tract was confirmed by an in vivo pathogenicity test using a murine model. Antimicrobial activity was displayed against several airborne pathogens. Potential antimicrobial metabolites such as 2,3-butanediol and propylene glycol were identified as possible antagonistic agents. Immunomodulatory properties in vitro were confirmed by upregulation of IL-10 expression in a macrophage cell line. Intranasal instillation and inhalation in an ovalbumin (OVA)-induced lung inflammation murine model reduced T helper type 2 (Th2) cytokines at transcriptional and protein levels in the lungs. The safety and potentially beneficial role of these Bacillus strains could be demonstrated for the respiratory tract of a murine model.

Morphological rearrangement of the metabolic link of the microcirculatory bed of guinea pigs lungs after sensitization with ovalbumin

The reaction of the lung microvessels is an urgent issue of morphology and medicine in general, as well as one of the insufficiently investigated points in the study of morphological changes in chronic allergic diseases of the respiratory system.
 The aim is to study the morphological changes in the vessels of the metabolic link of the microcirculation in the lungs of guinea pigs sensitized with ovalbumin.
 Materials and methods. We have studied the lungs of 48 guinea pigs, using histological and morphometric methods, under conditions of experimental ovalbumin-induced allergic inflammation, simulated by three-time subcutaneous sensitization and subsequent 8-day intranasal inhalation of ovalbumin. To estimate the structural and functional state of capillaries, the inner diameter of the vessels was determined.
 Results. A general regularity in the reactivity of the hemomicrocirculatory bed of guinea pig lungs in experimental ovalbumin-induced allergic inflammation was established, which consists in a significant structural and functional restructuring of the exchange vessels of the microcirculatory bed. Dysfunction of the capillaries endothelium is manifested by a change of vasodilatation to vasospasm, as evidenced by morphometric changes in the diameter of the capillaries lumen in the experimental groups, and an increase in the permeability of the capillaries wall, which is confirmed by edema and disorganization of the connective tissue component.
 Conclusions. Allergic inflammation leads to structural and functional reorganization of the metabolic link of the hemomicrocirculatory bed of guinea pig lungs, which has a multidirectional staging character depending on the duration of the experiment and is a manifestation of a violation of the compensatory-adaptive processes of hemomicrocirculation. The most pronounced changes in the form of a decrease in the diameter of the lumen of the blood capillaries of the lungs of guinea pigs by 23 % compared to the control are observed during the late period of the development of the allergic inflammatory process.

MicroRNA-21 Inhibition Suppresses Alveolar M2 Macrophages in an Ovalbumin-Induced Allergic Asthma Mice Model

PurposeMicroRNA-21 (miR-21) influences the Th2 immune pathway by suppressing the expressions of interleukin (IL)-12 and interferon (IFN)-γ. The effects of miR-21 suppression on alveolar macrophage polarization and airway inflammation are not known.MethodsBALB/c and miR-21 knockout (KO) mice were sensitized and challenged with ovalbumin (OVA). The anti-miR-21 antagomir was administered to BALB/c mice by intranasal inhalation from the day of OVA sensitization. Changes in cell counts, cytokine levels in bronchoalveolar lavage fluid (BALF), and airway hyperresponsiveness (AHR) were examined. Total, M1, and M2 macrophages were examined in the lung tissues by immunohistochemistry (IHC). M2 macrophages from the OVA mice lung were inhaled into the anti-miR-21 antagomir-treated asthmatic mice. Moreover, the polarization of M0 to M2 macrophages upon IL-4 stimulation was analyzed after anti-miR-21 antagomir transfection.ResultsThe miR-21 KO mice showed decreases in AHR, total cell and eosinophil counts in BALF, and in the levels of IL-4, IL-5, IL-10, and IL-13. Expression of IL-12 and IFN-γ were increased in the miR-21 KO mice. Peribronchial inflammation and goblet cell dysplasia were significantly decreased in the lung tissues of miR-21 KO OVA mice compared to the wild type OVA mice. IHC for M1, M2, and total macrophage in the lung tissues showed that miR-21 inhalation suppressed alveolar M2 macrophages in KO mice. M2 macrophage inhalation restored AHR and eosinophilic airway inflammation in the miR-21 antagomir-treated mice. Moreover, anti-miR-21 antagomir transfection decreased the expression of M2 markers and increased the expression of M1 markers in M0 macrophages after IL-4 stimulation.ConclusionsThe results suggest that miR-21 antagonism could suppress alveolar M2 macrophage polarization, decreasing not only the Th2 eosinophilic airway inflammation but also AHR and airway remodeling process.

Morphometric characteristics of distal airways of guinea pigs sensitized with ovalbumin

The reaction of the structural components of small bronchi and terminal bronchioles is the urgent issue of morphology and medicine in general, as well as one of the insufficiently studied issue in the study of morphological changes in the airways with allergic inflammation in the chronobiological aspect. The purpose of this work is to study the morphometric parameters of distal airways of guinea pigs sensitized with ovalbumin. We have studied the lung of 48 guinea pigs, using histological, morphometric and statistical methods under conditions of experimental ovalbumin-induced allergic inflammation, simulated by three times subcutaneous sensitization and subsequent 8-day intranasal inhalation of ovalbumin. The thickness of mucosa, muscular layer and adventitial layer was determined to assess morphometric parameters of bronchioles and terminal bronchioles. There are reactive changes in morphometric parameters of bronchioles on the 23rd and 30th days of observation, such as the thinning of mucosa and on the 36th day such as muscular-fibrous hyperplasia, accompanied by the narrowing of the bronchioles lumen. There are the most significant confirmed statistically changes in the terminal bronchioles on the 36th day of the experiment such as the thickening of mucosa and adventitial layer, accompanied by muscular hyperplasia and edema of the connective tissue stroma. Thus, sensitization and allergization with ovalbumin of experimental animals cause morpho-functional changes in the structural elements of the wall of bronchioles and terminal bronchioles, which have a staged, mainly multidirectional character and correspond to the main morphological manifestations of allergic inflammation with maximal changes in the late period of its development (the 36th day of the experiment).

Oral SARS-CoV-2 Inoculation Establishes Subclinical Respiratory Infection with Virus Shedding in Golden Syrian Hamsters

SummarySevere acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is transmitted largely by respiratory droplets or airborne aerosols. Despite being frequently found in the immediate environment and feces of patients, evidence supporting the oral acquisition of SARS-CoV-2 is unavailable. Using the Syrian hamster model, we demonstrate that the severity of pneumonia induced by the intranasal inhalation of SARS-CoV-2 increases with virus inoculum. SARS-CoV-2 retains its infectivity in vitro in simulated human-fed-gastric and fasted-intestinal fluid after 2 h. Oral inoculation with the highest intranasal inoculum (105 PFUs) causes mild pneumonia in 67% (4/6) of the animals, with no weight loss. The lung histopathology score and viral load are significantly lower than those infected by the lowest intranasal inoculum (100 PFUs). However, 83% of the oral infections (10/12 hamsters) have a level of detectable viral shedding from oral swabs and feces similar to that of intranasally infected hamsters. Our findings indicate that the oral acquisition of SARS-CoV-2 can establish subclinical respiratory infection with less efficiency.

Bioaccumulation of ytterbium oxide nanoparticles insinuate oxidative stress, inflammatory, and pathological lesions in ICR mice.

With the rapid development in nanoscience and nanotechnology, rare earth oxide nanomaterials (REO-NMs) have been increasingly used due to their unique physical and chemical characteristics. Despite the increasing applications of REO NPs, scarce information is available on their detrimental effects. In the current study, we investigate the toxic effect of ytterbium oxide nanoparticles (Yb2O3 NPs) in mouse model by using various techniques including inductively coupled plasma mass spectrometry (ICP-MS) analysis over 30days of exposure. Furthermore, we elucidated lung lavage fluid of mice for biochemical and cytological analysis, and lung tissues for histopathology to interpret the NP side effects. We observed a significant concentration of Yb2O3 NPs accumulated in the lung, liver, kidney, and heart tissues. Similarly, increased bioaccumulation of Yb content was found in the olfactory bulb compared to other reigns of brain. The cytological analysis of bronchoalveolar lavage fluid (BALF) revealed a significant elevation in the percentage of neutrophils and lymphocytes. Biochemical analysis showed an instilled Yb2O3 NPs, showing signs of oxidative damage through up-regulation of 60-87% of MDA while down-regulation of 20-40% of GSH-PX and GSH content. The toxicity pattern was more evident from histopathological observations. These interpretations provide enough evidence of bioaccumulation of Yb2O3 NPs in mice tissues. Overall, our findings reveal that acute exposure of Yb2O3 NPs through intranasal inhalation may cause toxicity via oxidative stress, which leads to a chronic inflammatory response. Graphical abstract Graphical illustrations of experimental findings.

Oral SARS-CoV-2 Inoculation Establishes Subclinical Respiratory Infection with Virus Shedding in Golden Syrian Hamsters

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is transmitted largely by respiratory droplets or airborne aerosols. Despite being frequently found in the immediate environment and faeces of patients, evidence supporting oral acquisition of SARS-CoV-2 is unavailable. Utilizing Syrian hamster model, we demonstrated that the severity of pneumonia induced by intranasal inhalation of SARS-CoV-2 increased with virus inoculum. SARS-CoV-2 retained its infectivity in vitro in simulated human fed-gastric and fasted-intestinal fluid after two hours. Oral inoculation with the highest intranasal inoculum (10 5 PFU) caused only mild pneumonia in 67% (4/6) of the animals with no clinical symptoms. The lung histopathology and viral load were significantly lower than those infected by the lowest intranasal inoculum (100 PFU). However, 83% oral infection (10/12 hamsters) had similar level of detectable viral shedding from oral swabs and faeces as intranasally infected hamsters. Our findings indicated oral acquisition of SARS-CoV-2 can establish asymptomatic respiratory infection with less efficiency.

Pbp1-Interacting Protein Mkt1 Regulates Virulence and Sexual Reproduction in Cryptococcus neoformans.

The Mkt1–Pbp1 complex promotes mating-type switching by regulating the translation of HO mRNA in Saccharomyces cerevisiae. Here, we performed in vivo immunoprecipitation assays and mass spectrometry analyses in the human fungal pathogen Cryptococcus neoformans to show that Pbp1, a poly(A)-binding protein-binding protein, interacts with Mkt1 containing a PIN like-domain. Association of Pbp1 with Mkt1 was confirmed by co-immunoprecipitation assays. Results of spot dilution growth assays showed that unlike pbp1 deletion mutant strains, mkt1 deletion mutant strains were not resistant to heat stress compared with wild-type. However, similar to the pbp1 deletion mutant strains, the mkt1 deletion mutants exhibited both, defective dikaryotic hyphal production and reduced pheromone gene (MFα1) expression during mating. In addition, deletion of mkt1 caused attenuated virulence in a murine intranasal inhalation model. Taken together, our findings reveal that Mkt1 plays a crucial role in sexual reproduction and virulence in C. neoformans.

Insufficient zinc intake enhances lung inflammation in response to agricultural organic dust exposure

Organic dust exposure particularly within hog confinement facilities is a significant cause of airway inflammation and lung disease. In a cohort of Midwestern veterans with COPD and agricultural work exposure we observed reduced zinc intakes which were associated with decreased lung function. Because insufficient zinc intake is common within the U.S. and a potent modulator of innate immune function, we sought to determine whether deficits in zinc intake would impact the airway inflammatory response to hog confinement facility dust extract (HDE). Adult male C57BL/6 mice were randomized to zinc deficient or matched zinc sufficient diets for 3 weeks and subsequently treated with intranasal HDE inhalation or saline once or daily for 3 weeks while maintained on specific diets. Lavage fluid and lung tissue was collected. Conditions of zinc deficiency were also studied in macrophages exposed to HDE. Single and repetitive HDE inhalation exposure resulted in increased influx of total cells and neutrophils, increased mediator hyper-responsiveness (TNFα, IL-6, CXCL1, and amphiregulin), and enhanced tissue pathology that was more pronounced in zinc deficient mice compared to normal dietary counterparts. Airway inflammation was most pronounced in zinc deficient mice treated with repetitive HDE for 3 weeks. Similarly, macrophages maintained in a zinc deficient environment exhibited increased CXCL1 and IL-23 production as a result of increased NF-κB activation.Conclusion: Given the relatively high incidence of dietary deficiencies in agriculture workers, we anticipate that zinc intake, or a lack thereof, may play an important role in modulating the host response to organic dust exposure.

Safety and sedative effect of intranasal dexmedetomidine in mandibular third molar surgery: a systematic review and meta-analysis.

ObjectiveThe focus of this meta-analysis was to assess the sedative effect and safety of intranasal dexmedetomidine (Dex) in mandibular third molar surgery.MethodsThe PubMed/Medline, Web of Science, Cochrane Library, and China National Knowledge Infrastructure databases were searched for studies published until May 1, 2018. Eligible studies were restricted to randomized controlled trials (RCTs) and controlled clinical trials. The evaluation indicators mainly included the bispectral index, observer assessment of alertness/sedation scale, systolic blood pressure, and heart rate. Data for each period in the Dex and control groups were pooled to evaluate its sedative effect and safety.ResultsFive RCTs met the inclusion criteria. This study included 363 patients: 158 patients received intranasal inhalation of Dex before surgery, and 158 patients were negative controls. The pooled results showed a good sedative effect during tooth extraction when intranasal inhalation of Dex was performed 30 minutes before third molar extraction (assessment of alertness/sedation, Dex vs control SMD −1.20, 95% CI −1.73 to −0.67, I2=0, P=0.95; bispectral index, Dex vs control SMD −11.68, 95% CI −19.49 to −3.87, I2=89%; P=0.0001), and parameters returned to normal within 90 minutes after inhalation. During the operation, blood pressure and heart rate decreased to some extent, but the decreases did not exceed 20% of the baseline, and all patients returned to normal conditions within 90 minutes after inhalation.ConclusionIntranasal inhalation of Dex 30 minutes before third molar extraction can provide a good sedative effect, and large-sample multicenter RCTs are needed to evaluate the analgesic effect of Dex.

Ovalbumin-sensitized mice have altered airway inflammation to agriculture organic dust

Agriculture exposures are associated with reducing the risk of allergy and asthma in early life; yet, repeated exposures later in life are associated with chronic bronchitis and obstructive pulmonary diseases. The objective of this study was to investigate the airway inflammatory response to organic dust extract (ODE) in mice with established ovalbumin (OVA)-induced experimental asthma. C57BL/6 mice were either OVA sensitized/aerosol-exposed or saline (Sal) sensitized/aerosol-challenged. Both groups were then subsequently challenged once with intranasal saline or swine confinement ODE to obtain 4 treatment groups of Sal-Sal, Sal-ODE, OVA-Sal, and OVA-ODE. Airway hyper-responsiveness (AHR) to methacholine, bronchiolar lavage fluid, lung tissues, and serum were collected. Intranasal inhalation of ODE in OVA-treated (asthmatic) mice (OVA-ODE) increased AHR and total cellular influx marked by elevated neutrophil and eosinophil counts. Flow cytometry analysis further demonstrated that populations of CD11chi dendritic cells (DC), CD3+ T cells, CD19+ B cells, and NKp46+ group 3 innate lymphoid cells (ILC3) were increased in lavage fluid of OVA-ODE mice as compared to ODE or OVA alone. Alveolar macrophages, DC, and T cells were significantly increased with co-exposure to OVA-ODE as compared to OVA alone. Lung ILC2 and ILC3 were only increased in OVA-Sal mice. Cytokine/chemokine levels varied with exposure to OVA-ODE reflecting an additive mixture of the pro- and allergic-inflammatory profiles. Collectively, ODE increased airway inflammatory cells and chemotactic mediator release in allergic (OVA) sensitized mice to suggest that persons with allergy/asthma be identified and warned prior to the occupational exposure of potentially worsening airway disease.

MyD88 controls airway epithelial Muc5ac expression during TLR activation conditions from agricultural organic dust exposure.

Inflammation from airborne microbes can overwhelm compensatory mucociliary clearance mechanisms, leading to mucous cell metaplasia. Toll-like receptor (TLR) activation via myeloid differentiation factor 88 (MyD88) signaling is central to pathogen responses. We have previously shown that agricultural organic dust extract (ODE), with abundant microbial component diversity, activates TLR-induced airway inflammation. With the use of an established model, C57BL/6J wild-type (WT) and global MyD88 knockout (KO) mice were treated with intranasal inhalation of ODE or saline, daily for 1 wk. ODE primarily increased mucin (Muc)5ac levels relative to Muc5b. Compared with ODE-challenged WT mice, ODE-challenged, MyD88-deficient mice demonstrated significantly increased Muc5ac immunostaining, protein levels by immunoblot, and expression by quantitative PCR. The enhanced Muc5ac levels in MyD88-deficient mice were not explained by differences in the differentiation program of airway secretory cells in naïve mice. Increased Muc5ac levels in MyD88-deficient mice were also not explained by augmented inflammation, IL-17A, or neutrophil elastase levels. Furthermore, the enhanced airway mucins in the MyD88-deficient mice were not due to defective secretion, as the mucin secretory capacity of MyD88-KO mice remained intact. Finally, ODE-induced Muc5ac levels were enhanced in MyD88-deficient airway epithelial cells in vitro. In conclusion, MyD88 deficiency enhances airway mucous cell metaplasia under environments with high TLR activation.

TARGETING THE TRANS-IL-6 SIGNALING PATHWAY TO REDUCE AGRICULTURE ORGANIC DUST EXPOSURE-INDUCED AIRWAY INFLAMMATION IN MICE

SESSION TITLE: Occupational and Environmental Lung Diseases SESSION TYPE: Original Investigation Posters PRESENTED ON: 10/10/2018 01:00 PM - 02:00 PM PURPOSE: Agricultural workers experience high rates of chronic inflammatory lung disease from inhalation of organic dusts. Interleukin (IL)-6 is an important cytokine linked to chronic lung disease and organic dust extract (ODE) exposure. IL-6 can activate either an anti-inflammatory (classic) or pro-inflammatory (trans) IL-6 signaling pathway. Blocking the trans-IL-6 pathway with a soluble gp130Fc protein may decrease inflammation and offer a future targeted therapy for agricultural workers. METHODS: C57BL/6 mice were pretreated with intraperitoneal injection of recombinant gp130Fc (2μg) or a vehicle control followed by intranasal inhalation of swine confinement facility ODE or a saline control daily for 9 days. Bronchoalveolar lavage fluid (BALF), lung tissue homogenates, and serum were collected for inflammatory, cellular, and cytokine analysis. Lungs were processed for histopathology and independently scored for inflammatory changes. Serum soluble-IL-6 receptor levels and serum IL-6 levels were used to determine whether gp130Fc treated animals obtained adequate therapy. Data collected from a minimum of 3 independent experiments with total of 8-12 mice per treatment group. RESULTS: ODE-induced neutrophil influx was not reduced by gp130Fc pre-treatments (p=0.61), but inflammatory mediators were decreased. Pretreatment with gp130Fc significantly reduced ODE-induced BALF levels of CXCL1 by 83% (p=0.021), CXCL2 by 102% (p=0.003), IL-6 by 86% (p=0.004), and TNF-α by 125% (p=0.009). In lung tissue, there was a significant increase in IL-12 by 72% (p=0.020), a non-significant decrease in IL-17 by 35% (p=0.400), and a non-significant increase in IL-13 by 38% (p=0.124). There were also non-significant reductions in ODE-induced lung histopathological inflammatory scoring marked by less alveolar inflammation (p=0.083), bronchial inflammation (p=0.083), and lymphoid aggregate development (p=0.100) in animals pretreated with gp130Fc. There were no differences in any outcome between vehicle injection+saline inhalation and gp130Fc injection+saline inhalation treatment groups. CONCLUSIONS: Targeting the trans-IL-6 signaling pathway by intraperitoneal administration of recombinant gp130Fc in mice prior to organic dust extract exposures attenuates the airway inflammatory response. The inhibitory effect of gp130Fc was predominately evident by reductions in ODE-induced inflammatory cytokines/chemokines and to a lesser degree in ODE-associated lung histopathology. CLINICAL IMPLICATIONS: In 2015 an estimated 2.05 million documented US citizens worked in agriculture. Of those who work with swine, up to 93% report development of respiratory symptoms. Chronic inflammatory lung disease has been well established in this sub-population. Identifying a targeted therapy, such as recombinant gp130Fc, that can prevent lung inflammation in these individuals could potentially offer an important clinical benefit. DISCLOSURES: No relevant relationships by Joseph Carrington, source=Web Response No relevant relationships by Amy Nelson, source=Web Response No relevant relationships by Jill Poole, source=Web Response No relevant relationships by Debra Romberger, source=Web Response No relevant relationships by Benjamin Swanson, source=Web Response

Sex differences impact the lung-bone inflammatory response to repetitive inhalant lipopolysaccharide exposures in mice

Skeletal health consequences associated with inflammatory diseases of the airways significantly contribute to morbidity. Sex differences have been described independently for lung and bone diseases. Repetitive inhalant exposure to lipopolysaccharide (LPS) induces bone loss and deterioration in male mice, but comparison effects in females are unknown. Using an intranasal inhalation exposure model, 8-week-old C57BL/6 male and female mice were treated daily with LPS (100 ng) or saline for 3 weeks. Bronchoalveolar lavage fluids, lung tissues, tibias, bone marrow cells, and blood were collected. LPS-induced airway neutrophil influx, interleukin (IL)-6 and neutrophil chemoattractant levels, and bronchiolar inflammation were exaggerated in male animals as compared to female mice. Trabecular bone micro-CT imaging and analysis of the proximal tibia were conducted. Inhalant LPS exposures lead to deterioration of bone quality only in male mice (not females) marked by decreased bone mineral density, bone volume/tissue volume ratio, trabecular thickness and number, and increased bone surface-to-bone volume ratio. Serum pentraxin-2 levels were modulated by sex differences and LPS exposure. In proof-of-concept studies, ovarectomized female mice demonstrated LPS-induced bone deterioration, and estradiol supplementation of ovarectomized female mice and control male mice protected against LPS-induced bone deterioration findings. Collectively, sex-specific differences exist in LPS-induced airway inflammatory consequences with significant differences found in bone quantity and quality parameters. Male mice demonstrated susceptibility to bone loss and female animals were protected, which was modulated by estrogen. Therefore, sex differences influence the biologic response in the lung-bone inflammatory axis in response to inhalant LPS exposures.

A role for B cells in organic dust induced lung inflammation

BackgroundAgriculture organic dust exposures induce lung disease with lymphoid aggregates comprised of both T and B cells. The precise role of B cells in mediating lung inflammation is unknown, yet might be relevant given the emerging role of B cells in obstructive pulmonary disease and associated autoimmunity.MethodsUsing an established animal model, C57BL/6 wild-type (WT) and B-cell receptor (BCR) knock-out (KO) mice were repetitively treated with intranasal inhalation of swine confinement organic dust extract (ODE) daily for 3 weeks and lavage fluid, lung tissues, and serum were collected.ResultsODE-induced neutrophil influx in lavage fluid was not reduced in BCR KO animals, but there was reduction in TNF-α, IL-6, CXCL1, and CXCL2 release. ODE-induced lymphoid aggregates failed to develop in BCR KO mice. There was a decrease in ODE-induced lung tissue CD11c+CD11b+ exudative macrophages and compensatory increase in CD8+ T cells in lavage fluid of BCR KO animals. Compared to saline, there was an expansion of conventional B2-, innate B1 (CD19+CD11b+CD5+/−)-, and memory (CD19+CD273+/-CD73+/−) B cells following ODE exposure in WT mice. Autoreactive responses including serum IgG anti-citrullinated protein antibody (ACPA) and anti-malondialdehyde-acetaldehyde (MAA) autoantibodies were increased in ODE treated WT mice as compared to saline control. B cells and serum immunoglobulins were not detected in BCR KO animals.ConclusionsLung tissue staining for citrullinated and MAA modified proteins were increased in ODE-treated WT animals, but not BCR KO mice. These studies show that agriculture organic dust induced lung inflammation is dependent upon B cells, and dust exposure induces an autoreactive response.

Association of Radon Background and Total Background Ionizing Radiation with Alzheimer’s Disease Deaths in U.S. States

Exposure of the brain to ionizing radiation might promote the development of Alzheimer's disease (AD). Analysis of AD death rates versus radon background radiation and total background radiation in U.S. states. Total background, radon background, cosmic and terrestrial background radiation measurements are from Assessment of Variations in Radiation Exposure in the United States and Report No. 160 - Ionizing Radiation Exposure of the Population of the United States. 2013 AD death rates by U.S. state are from the Alzheimer's Association. Radon background ionizing radiation was significantly correlated with AD death rate in 50 states and the District of Columbia (r = 0.467, p = 0.001). Total background ionizing radiation was also significantly correlated with AD death rate in 50 states and the District of Columbia (r = 0.452, p = 0.001). Multivariate linear regression weighted by state population demonstrated that AD death rate was significantly correlated with radon background (β= 0.169, p < 0.001), age (β= 0.231, p < 0.001), hypertension (β= 0.155, p < 0.001), and diabetes (β= 0.353, p < 0.001). Our findings, like other studies, suggest that ionizing radiation is a risk factor for AD. Intranasal inhalation of radon gas could subject the rhinencephalon and hippocampus to damaging radiation that initiates AD. The damage would accumulate over time, causing age to be a powerful risk factor.

Comparison of traditional intranasal and aerosol inhalation inoculation of guinea pigs with visualizing influenza virus

Influenza A virus has caused intermittent pandemics with potentially devastating consequences in human populations. Under natural conditions, influenza virus is mainly spread person-to-person through the air; however, in studies of influenza virology, the virus is typically intranasally instilled in the form of large liquid droplets. The dynamics of influenza virus infection and real-time progression of respiratory tract infection are still poorly understood, partly due to a lack of available efficient replication-competent viruses that stably express a reporter gene. To address this limitation, we constructed a replication-competent influenza A virus carrying a Gaussia luciferase reporter gene in the NA segment of the viral genome (IAV-Gluc). The recombinant virus (IAV-Gluc) stably expressed Gaussia luciferase, and the viral load in lungs was proportional to the fluorescence intensity. Although IAV-Gluc was less virulent than wild-type virus (PR8), it efficiently infected and replicated within murine lungs and was pathogenic in mice. After challenging guinea pigs with the equivalent doses of virus using two different methods, namely, intranasal (IN) inoculation and aerosol exposure (AR), it was found that the animals subjected to IN inoculation showed greater virus deposition in the lungs (12.27%) than those subjected to AR (1.34%), although the latter group exhibited more rapid viral replication within 48h. Combining the results of live-animal imaging and traditional techniques used to measure viral titer, we identified additional differences between IN inoculation and AR. For example, IN inoculation caused the virus to distribute in a punctate pattern throughout the lungs, whereas virus delivered through AR showed an even distribution pattern, which increased the efficiency of viral replication. Indeed, the replication efficiency of the AR group was 11,073-fold higher than the original deposition amount after 48h, whereas that of the IN group was only 15.4-fold higher than the original deposition amount after 24h.

Inhibition of MicroRNA-21 by an antagomir ameliorates allergic inflammation in a mouse model of asthma

ABSTRACTAim of the Study: MicroRNA-21 (miR-21) is up-regulated during allergic airway inflammation, reflecting a Th2 immune response. We investigated the effects of an miR-21 antagomir and its mechanism of action in a mouse model of acute bronchial asthma. Materials and Methods: BALB/c mice were sensitized and challenged with ovalbumin (OVA). The anti-miR-21 antagomir was administered by intranasal inhalation from the day of sensitization. Changes in cell counts, Th2 cytokine levels in bronchoalveolar (BAL) fluid, and airway hyper-responsiveness (AHR) were examined. Histopathological changes and expression levels of miR-21 in lung tissues were analyzed. The mechanism of action of the antagomir was investigated by counting CD4+/CD8− T cells in splenocytes and by measuring the expression levels of transcription factors associated with T cell polarization. Results: MiR-21 expression was selectively down-regulated in the lung tissues of mice treated with anti-miR-21. The antagomir suppressed AHR compared with that of the OVA-challenged and scrambled RNA-treated groups. It also reduced the total cell and eosinophil counts in BAL fluid and the levels of Th2 cytokines, including IL-4, IL-5, and IL-13. The direct target of miR-21, IL-12p35, was induced in the antagomir-treated group, decreasing the CD4+/CD8− T cell proportions in splenocytes. The levels of transcription factors involved in the Th2-signaling pathway were reduced in lung tissues on treatment with the antagomir. Conclusions: The miR-21 antagomir suppresses the development of allergic airway inflammation in a mouse model of acute bronchial asthma, inhibiting Th2 activation. These results suggest that this antagomir might be useful for treating bronchial asthma.

The natural product bergenin ameliorates lipopolysaccharide-induced acute lung injury by inhibiting NF-kappaB activition

Ethnopharmacological relevanceBergenin, an active constituent of the plants of the genus Bergenia, was reported to have anti-inflammatory effects in the treatment of chronic bronchitis and chronic gastritis clinically. However, its therapeutic effect on lipopolysaccharide (LPS)-induced acute lung injury (ALI) and its potential mechanisms of actions were still unknown. Aim of this studyTo evaluate the effect of bergenin on murine model of acute lung injury induced by LPS and also to explore its potential mechanisms. Materials and methodsHalf an hour and 12h after an intranasal inhalation of LPS, male BALB/c mice were treated with bergenin (50,100 and 200mg/kg) or dexamethasone (DEX, 5mg/kg) by gavage. Twenty-four hours after LPS exposure, the lung wet/dry ratio, histological changes, myeloperoxidase (MPO) in lung tissues, inflammatory cells (in BALF) and cytokines (in BALF and serum) were detected. Meanwhile, the protein expression of MyD88 and the phosphorylation of NF-κB p65 in lung tissue were analyzed using immunoblot analysis. Moreover, the nuclear translocation and the phosphorylation of NF-κB p65 in Raw264.7 cells were also analyzed. The viability of Raw264.7 cells was determined by MTT assay. ResultsResults showed that bergenin significantly decreased pulmonary edema, improved histological changes and reduced MPO activity in lung tissues. Moreover, bergenin obviously decreased inflammatory cells, IL-1β and IL-6 production in BALF, as well as IL-1β, TNF-α and IL-6 production in serum of LPS-induced ALI mice. Furthermore, bergenin markedly inhibited LPS-induced NF-κB p65 phosphorylation, as well as the expression of MyD88 but not the expression of NF-κB p65 in lung tissues. Additionally, bergenin also significantly inhibited the nuclear translocation and the phosphorylation of NF-κB p65 stimulated by LPS in Raw264.7 cells. ConclusionsThese findings suggested that bergenin had a therapeutic effect on LPS-induced ALI by inhibiting NF-κB activition.

Alcohol Inhibits Organic Dust-induced ICAM-1 Expression on Bronchial Epithelial Cells.

Aims: Exposure to dusts/bioaerosols in concentrated animal feeding operations (CAFOs) results in inflammatory lung diseases in workers. Hog CAFOs dust extract (HDE) increases expression of intercellular adhesion molecule-1 (ICAM-1), neutrophil adhesion, and TNFα release in bronchial epithelial cells. Alcohol consumption is increasingly recognized to impair lung immunity. We hypothesized that alcohol impairs HDE-induced TNFα, ICAM-1 expression and neutrophil adhesion by directly inhibiting TNFα converting enzyme (TACE) activity.MethodsBronchial epithelial cells (BEAS-2B) and primary human bronchial epithelial cells were pretreated with ethanol (EtOH) or TACE inhibitor. ICAM-1 surface expression, TNFα release, and TACE activity were analyzed following HDE stimulation. The effect of alcohol and TACE inhibition on HDE-regulated epithelial cell/neutrophil adhesion interactions was investigated. Finally, utilizing an established animal model, C57BL/6 mice were fed ad libitum ethanol (20%) in drinking water for 8 wk followed by daily intranasal inhalation of HDE or saline during the final two weeks. Mice were sacrificed and lung sections immunostained for ICAM-1.ResultsPretreatment with alcohol or TACE inhibitor significantly decreased HDE-induced ICAM-1 expression and TNFα release. HDE augmented neutrophil adhesion to epithelial cells, which was decreased with alcohol (32% decrease) or TACE inhibitor (55% decrease) pretreatment. TACE activity increased following HDE exposure, but TACE activity was inhibited following alcohol pretreatment. Alcohol-fed mice demonstrated decreased HDE-induced airway epithelium ICAM-1 expression.ConclusionsAlcohol diminishes HDE-induced ICAM-1 expression, TNFα release, and neutrophil adhesion via inhibition of TACE activity. These results suggest that alcohol may be an important modulator of lung innate immune responses following CAFO exposure.