Predictive signature of murine and human host response to typical and atypical pneumonia.

BACKGROUND: Pneumonia due to typical bacterial, atypical bacterial and viral pathogens can be difficult to clinically differentiate. Host response-based diagnostics are emerging as a complementary diagnostic strategy to pathogen detection. METHODS: We used murine models of typical bacterial, atypical bacterial and viral pneumonia to develop diagnostic signatures and understand the host's response to these types of infections. Mice were intranasally inoculated with Streptococcus pneumoniae, Mycoplasma pneumoniae, influenza or saline as a control. Peripheral blood gene expression analysis was performed at multiple time points. Differentially expressed genes were used to perform gene set enrichment analysis and generate diagnostic signatures. These murine-derived signatures were externally validated in silico using human gene expression data. The response to S. pneumoniae was the most rapid and robust. RESULTS: Mice infected with M. pneumoniae had a delayed response more similar to influenza-infected animals. Diagnostic signatures for the three types of infection had 0.94-1.00 area under the receiver operator curve (auROC). Validation in five human gene expression datasets revealed auROC of 0.82-0.96. DISCUSSION: This study identified discrete host responses to typical bacterial, atypical bacterial and viral aetiologies of pneumonia in mice. These signatures validated well in humans, highlighting the conserved nature of the host response to these pathogen classes.

Microsurgical clipping versus endovascular therapy for treating patients with middle cerebral artery aneurysms presenting with neurological ischemic symptoms.

Studies comparing different treatment methods in patients with middle cerebral artery (MCA) aneurysms in different subgroups of onset symptoms are lacking. It is necessary to explore the safety and efficacy of open surgical treatment and endovascular therapy in patients with MCA aneurysms in a specific population. This study aimed to compare microsurgical clipping versus endovascular therapy regarding complication rates and outcomes in patients with MCA aneurysms presenting with neurological ischemic symptoms. This was a retrospective cohort study in which 9656 patients with intracranial aneurysms were screened between January 2014 and July 2022. Further, 130 eligible patients were enrolled. The primary outcome was the incidence of serious adverse events (SAEs) within 30 days of treatment, whereas secondary outcomes included postprocedural target vessel-related stroke, disabling stroke or death, mortality, and aneurysm occlusion rate. Among the 130 included patients, 45 were treated with endovascular therapy and 85 with microsurgical clipping. The primary outcome of the incidence of SAEs within 30 days of treatment was significantly higher in the clipping group [clipping: 23.5%(20/85) vs endovascular: 8.9%(4/45), adjusted OR:4.05, 95% CI:1.20-13.70; P = 0.024]. The incidence of any neurological complications related to the treatment was significantly higher in the clipping group [clipping:32.9%(28/85) vs endovascular:15.6%(7/45); adjusted OR:3.49, 95%CI:1.18-10.26; P = 0.023]. Postprocedural target vessel-related stroke, disabling stroke or death, mortality rate, and complete occlusion rate did not differ significantly between the two groups. Endovascular therapy seemed to be safer in treating patients with MCA aneurysms presenting with neurological ischemic symptoms compared with microsurgical clipping, with a significantly lower incidence of SAEs within 30 days of treatment and any neurological complications related to the treatment during follow-up.

Characteristics, Performance and Microbial Response of Aerobic Granular Sludge for Treating Tetracycline Hypersaline Pharmaceutical Wastewater.

Salt-tolerant aerobic granular sludge(AGS) was successfully cultivated under the dual stress of tetracycline and 2.5% salinity, resulting in an average particle size of 435.0 ± 0.5 and exhibiting a chemical oxygen demand(COD) removal rate exceeding 80%, as well as excellent sedimentation performance. The analysis of metagenomics technology revealed a significant pattern of succession in the development of AGS. The proportion of Oleiagrimonas, a type of salt-tolerant bacteria, exhibited a gradual increase and reached 38.07% after 42 days, which indicated that an AGS system based on moderate halophilic bacteria was successfully constructed. The expression levels of targeted genes were found to be reduced across the entire AGS process and formation, as evidenced by qPCR analysis. The presence of int1 (7.67 log10 gene copies g-1 in 0 d sludge sample) enabled microbes to horizontally transfer ARGs genes along the AGS formation under the double pressure of TC and 2.5% salinity. These findings will enhance our understanding of ARG profiles and the development in AGS under tetracycline pressure, providing a foundation for guiding the use of AGS to treat hypersaline pharmaceutical wastewater.

Efficacy and safety of Pien Tze Huang capsules in patients with herpes zoster: A multicenter, randomized, double-blinded, and placebo-controlled trial.

BACKGROUND: Herpes zoster (HZ) is a common medical condition accompanied by several distressing symptoms, including acute pain. Pien Tze Huang (PZH) is a well-known traditional Chinese medicine (TCM) with numerous pharmacological effects, including antiviral properties, neuroprotection, and immunity regulation. PURPOSE: To investigate the efficacy and safety of PZH capsules in patients with HZ. STUDY DESIGN: A multicenter, double-blinded, randomized, and placebo-controlled trial from 8 hospitals in 5 cities of China. METHODS: Eligible participants were randomly assigned to the PZH capsule and placebo group at a 1:1 ratio. Treatment was conducted for 14 days with a window period of no more than 2 days. For the first 7 days, participants received antiviral drugs combined with PZH capsules (0.6 g/time, 3 times a day) or placebos. For the remaining 7 days, they were only treated with PZH capsules (0.6 g/time, 3 times a day) or placebos. RESULTS: We included 222 patients in the full analysis set (FAS), and 187 patients in the per protocol set (PPS). The change of numeric rating scale pain scores from baseline to the seventh day (±1 day) after treatment in the PZH capsule group was statistically superior to the placebo group (FAS: 2.33 vs. 1.71, 97.5%CI: 0.03 ∼ 1.19; PPS: 2.29 vs. 1.51, 97.5%CI: 0.18 ∼ 1.38). In the PPS, there was a significant difference in the time (days) of pain relief between the placebo group and the PZH capsule group (Mean (SD): 5.71 (3.76) vs. 4.69 (3.57), p = 0.046). On the seventh day (±1 day) after treatment, the level of CD8+ cells in the PZH capsule group were higher than those of the placebo group (FAS: Mean (SD): 24.08 (6.81) vs. 21.93 (8.19), p = 0.007; PPS: Mean (SD): 24.26 (6.93) vs. 22.15 (8.51), p = 0.012). The level of cytotoxic lymphocyte cells found similar results on the seventh day (±1 day) (FAS: Mean (SD): 12.17 (4.65) vs. 10.55 (4.15), p = 0.018; PPS: Mean (SD): 12.25 (4.65) vs. 10.11 (3.93), p = 0.002). No serious adverse events were noted and PZH capsules were well tolerated. CONCLUSION: PZH capsules confer therapeutic effects on HZ with the TCM symptom of stagnated heat of liver channel by substantially reducing the pain intensity, shortening the time of pain relief as well as regulating the immune function. On the basis of the efficacy and safety profiles, PZH capsules may be a promising complementary therapy for the treatment of HZ.

Eight new 2-(2-phenylethyl)chromone derivatives from agarwood of Aquilaria sinensis with anti-inflammatory activity.

Eight previously unknown 2-(2-phenylethyl)chromone derivatives, called aquichromones A - E (1-3, 5 and 6) and 8-epi-aquichromone C (4), including two pairs of enantiomers [(±)-1 and (±)-2] were isolated from the agarwood of Aquilaria sinensis. The structures and absolute stereochemistry of these natural products were elucidated by using spectroscopic and computational methods. The result of biological assay showed that two members of this group, 4 and 5, have significant dose-dependent anti-inflammatory activity.

Meroterpenoids from Ganoderma petchii inhibiting migration of triple negative breast cancer cells.

Ganoderpetchoids A-E and (-)-dayaolingzhiol H, six undescribed meroterpenoids, were isolated from Ganoderma petchii. Their structures including the relative configurations were identified by means of spectroscopic methods and 13C NMR calculations. Chiral separation of the new racemics was performed to afford their respective enantiomers. The absolute configurations of the new isolates were clarified by computational approaches, CD comparisons and X-ray diffraction analysis. Biological studies toward triple negative breast cancer indicated that (+)-6 and (-)-6 significantly inhibit the migration of MDA-MB-231 cell line.

Isolation and Characterization of trans-p-Hydroxycinnamoyl Meroterpenoids from Ganoderma sinensis.

Zizhines V, W, Y, Z, (±)-zizhines X, and Z1-Z3, and (±)-ganosinensol L, thirteen new compounds including four pairs of enantiomers and a known compound (-)-ganosinensol L, were isolated from the fruiting bodies of Ganoderma sinensis. Their structures were identified by spectroscopic, computational methods, and CD (circular dichroism spectroscopy) comparisons. Zizhines V-Z and Z1-Z3 are meroterpenoids consisting of the phenolic and the terpenoidal parts. All the compounds except zizhine Z3 bear a common trans-p-hydroxycinnamoyl group. Biological evaluation shows that (-)-zizhine Z1 inhibits cell migration in the MDA-MB-231 cell lines. The present study discloses the chemical profiling of G. sinensis and paves the way for its development as functional products to benefit chronic disorders.

VMP1 promotes exosome secretion and enhances 5-FU resistance in colon cancer cells.

BACKGROUND: Drug resistance of colon cancer cells is the key to affect the efficacy of colon cancer chemotherapy and lead to chemotherapy failure. Recent studies have found that exosomes play an important role in chemoresistance of colon cancer, while the expression of VMP1 may be involved in exosome secretion. METHOD: Drug sensitivity of colon cancer cells was detected by MTT. VMP1 expression levels were detected by qPCR and western blot. Expression of VMP1 was silenced in SW620 and HT-29 cell lines. Exosomes were isolated by ultracentrifugation, the particle size and concentration of exosomes were analyzed by NTA, and the morphology of exosomes was investigated by transmission electron microscopy. Exosome marker protein expression was detected by Western blot. The effect of exosomes on 5-FU sensitivity in SW620 and HT-29 cells was examined by MTT and western blot. RESULTS: VMP1 presented high expression in SW620 and HT-29 cells, their VMP1 gene and protein levels were significantly higher than those in SW480 and HCT116 cells, they were less sensitive to 5-FU, and exosome secretion was significantly reduced in SW620 and HT-29 cells after silencing of VMP1. Importantly, addition of exosomes to cells after silencing of VMP1 re-improved drug resistance. Co-incubation of exosomes secreted from SW620 and HT-29 cells with homologous cells significantly increased cell viability after 5-FU (50 µM) treatment, and increased the expression levels of the resistance protein ABCC1 and the anti-apoptotic protein Bcl-2. CONCLUSION: High expression of VMP1 in colon cancer cells is able to promote exosome secretion, which mediates the acquisition of more drug-resistant properties by cancer cells.

Wood smoke particle exposure in mice reduces the severity of influenza infection.

Elevated ambient temperatures and extreme weather events have increased the incidence of wildfires world-wide resulting in increased wood smoke particle (WSP). Epidemiologic data suggests that WSP exposure associates with exacerbations of respiratory diseases, and with increased respiratory viral infections. To assess the impact of WSP exposure on host response to viral pneumonia, we performed WSP exposures in rodents followed by infection with mouse adapted influenza (HINI-PR8). C57BL/6 male mice aged 6-8 weeks were challenged with WSP or PBS by oropharyngeal aspiration in acute (single dose) or sub-acute exposures (day 1, 3, 5, 7 and 10). Additional groups underwent sub-acute exposure followed by infection by influenza or heat-inactivated (HI) virus. Following exposures/infection, bronchoalveolar lavage (BAL) was performed to assess for total cell counts/differentials, total protein, protein carbonyls and hyaluronan. Lung tissue was assessed for viral counts by real time PCR. When compared to PBS, acute WSP exposure associated with an increase in airspace macrophages. Alternatively, sub-acute exposure resulted in a dose dependent increase in airspace neutrophils. Sub-acute WSP exposure followed by influenza infection was associated with improved respiratory viral outcomes including reduced weight loss and increased blood oxygen saturation, and decreased protein carbonyls and viral titers. Flow cytometry demonstrated dynamic changes in pulmonary macrophage and T cell subsets based on challenge with WSP and influenza. This data suggests that sub-acute WSP exposure can improve host response to acute influenza infection.

Development of thermo-photo sensitive genic male sterile lines in wheat using doubled haploid breeding.

BACKGROUND: Two-line hybrid wheat system using thermo-photo sensitive genic male sterility (TPSGMS) is currently the most promising approach for wheat heterosis utilization in China. However, during past 20 years only few TPSGMS lines were developed in hybrid wheat breeding, which has been the main limiting factor to create heterotic hybrids. Application of doubled haploid (DH) breeding provides a useful strategy to efficiently develop practically usable TPSGMS lines. RESULTS: F1s and selected F2 and F3 sterile plants of eight crosses made from two commercial TPSGMS lines were used to produce DH lines. We developed a total of 24 elite DH sterile lines with stable sterility, good outcrossing and yield potential, resistance to yellow rust and powdery mildew, as well as desirable plant height (50-60 cm). These DH lines were developed within 4 years through at least 1 year of evaluation. The stability of male sterility was confirmed for most (20/24) of these elite DH sterile lines by multiple tests in two or 3 years. These lines are expected to be used in hybrid wheat breeding. The percentage of elite lines developed from the tested DH lines produced from filial generations was in the order of F2 > F3 > F1. CONCLUSIONS: We demonstrate that coupling DH techniques with conventional breeding is an efficient strategy for accelerating the development of more practical wheat TPSGMS lines. Generation of DHs from F2 generation appeared to be the better choice considering the balance of shortening breeding time and overall breeding efficiency.

Liuweibuqi capsules improve pulmonary function in stable chronic obstructive pulmonary disease with lung-qi deficiency syndrome by regulating STAT4/STAT6 and MMP-9/TIMP-1.

Context: Liuweibuqi (LWBQ) capsule has been reported to influence symptoms of patients with chronic obstructive pulmonary disease (COPD); however, specific function of LWBQ capsules in COPD with lung-qi deficiency syndrome remains elusive.Objective: This study investigates effect of LWBQ capsules on STAT4/STAT6 and MMP-9/TIMP-1 expression and pulmonary function in stable COPD with lung-qi deficiency syndrome.Materials and methods: Totally, 429 patients diagnosed with stable COPD and lung-qi deficiency syndrome were treated with starch capsules (each time for 9 capsules), or different doses: low (each dose for 8 capsules and 1 LWBQ capsules), medium (each time for 6 capsules and 3 LWBQ capsules), or high (each time for 9 LWBQ capsules) of LWBQ capsules for 30 days, 3 times a day. Forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC% and DLco%pred were evaluated by pulmonary function meter. STAT4/STAT6 and MMP-9/TIMP-1 expression was assessed by RT-qPCR and western blot analysis, and serum concentrations of IL-4, IFN-γ and IL-6 by ELISA.Results: Spearman rank correlation analysis and ROC curve showed that STAT4/STAT6 and MMP-9/TIMP-1 affected pulmonary functions and curative effect of stable COPD with lung-qi deficiency syndrome. After LWBQ capsule treatment, FEV1, FVC, FEV1/FVC% and DLco%pred elevated; STAT4/STAT6, MMP-9/TIMP-1, IFN-γ and IL-6 expression declined whereas IL-4 expression increased (p < 0.05). Logistic regression analysis demonstrated that FEV1/FVC was negatively correlated with STAT4/STAT6 and MMP-9/TIMP-1 expression in COPD patients.Conclusions: LWBQ capsules play a beneficial role in pulmonary function of stable COPD with lung-qi deficiency syndrome via STAT4/STAT6 and MMP-9/TIMP-1.

Identification of a Novel Inhibitor of Human Rhinovirus Replication and Inflammation in Airway Epithelial Cells.

Human rhinovirus (RV), the major cause of the common cold, triggers the majority of acute airway exacerbations in patients with asthma and chronic obstructive pulmonary disease. Nitric oxide, and the related metabolite S-nitrosoglutathione, are produced in the airway epithelium via nitric oxide synthase (NOS) 2 and have been shown to function in host defense against RV infection. We hypothesized that inhibitors of the S-nitrosoglutathione-metabolizing enzyme, S-nitrosoglutathione reductase (GSNOR), might potentiate the antiviral properties of airway-derived NOS2. Using in vitro models of RV-A serotype 16 (RV-A16) and mNeonGreen-H1N1pr8 infection of human airway epithelial cells, we found that treatment with a previously characterized GSNOR inhibitor (4-[[2-[[(3-cyanophenyl)methyl]thio]-4-oxothieno-[3,2-d]pyrimidin-3(4H)-yl]methyl]-benzoic acid; referred to as C3m) decreased RV-A16 replication and expression of downstream proinflammatory and antiviral mediators (e.g., RANTES [regulated upon activation, normal T cell expressed and secreted], CXCL10, and Mx1), and increased Nrf2 (nuclear factor erythroid 2-related factor 2)-dependent genes (e.g., SQSTM1 and TrxR1). In contrast, C3m had no effect on influenza virus H1N1pr8 replication. Moreover, a structurally dissimilar GSNOR inhibitor (N6022) did not alter RV replication, suggesting that the properties of C3m may be specific to rhinovirus owing to an off-target effect. Consistent with this, C3m antiviral effects were not blocked by either NOS inhibition or GSNOR knockdown but appeared to be mediated by reduced intercellular adhesion molecule 1 transcription and increased shedding of soluble intercellular adhesion molecule 1 protein. Collectively these data show that C3m has novel antirhinoviral properties that may synergize with, but are unrelated to, its GSNOR inhibitor activity.

Effect of the S-nitrosoglutathione reductase inhibitor N6022 on bronchial hyperreactivity in asthma.

RATIONALE: Patients with asthma demonstrate depletion of the endogenous bronchodilator GSNO and upregulation of GSNOR. OBJECTIVES: An exploratory proof of concept clinical study of N6022 in mild asthma to determine the potential bronchoprotective effects of GSNOR inhibition. Mechanistic studies aimed to provide translational evidence of effect. METHODS: Fourteen mild asthma patients were treated with intravenous N6022 (5 mg) or placebo and observed for 7 days, with repeated assessments of the provocative dose of methacholine causing a 20% fall in FEV1 (methacholine PC20 FEV1), followed by a washout period and crossover treatment and observation. In vitro studies in isolated eosinophils investigated the effect of GSNO and N6022 on apoptosis. MEASUREMENTS AND MAIN RESULTS: This was a negative trial as it failed to reach its primary endpoint, which was change from baseline in methacholine PC20 FEV1 at 24 h. However, our exploratory analysis demonstrated significantly more two dose-doubling increases in PC20 FEV1 for N6022 compared with placebo (21% vs 6%, P < 0.05) over the 7-day observation period. Furthermore, a significant treatment effect was observed in the change in PC20 FEV1 from baseline averaged over the 7-day observation period (mean change: +0.82 mg/ml [N6022] from 1.34 mg/ml [baseline] vs -0.18 mg/ml [placebo] from 1.16 mg/ml [baseline], P = 0.023). N6022 was well tolerated in mild asthmatics. In vitro studies demonstrated enhanced eosinophilic apoptosis with N6022. CONCLUSIONS: In this early phase exploratory proof of concept trial in asthma, N6022 did not significantly alter methacholine PC20 FEV1 at 24 h, but did have a treatment effect at 7 days compared to baseline. Further investigation of the efficacy of S-nitrosoglutathione reductase inhibition in a patient population with eosinophilic asthma is warranted.

Anatomical and diffusional determinants inside leaves explain the difference in photosynthetic capacity between Cypripedium and Paphiopedilum, Orchidaceae.

Comparing with other angiosperms, most members within the family Orchidaceae have lower photosynthetic capacities. However, the underlying mechanisms remain unclear. Cypripedium and Paphiopedilum are closely related phylogenetically in Orchidaceae, but their photosynthetic performances are different. We explored the roles of internal anatomy and diffusional conductance in determining photosynthesis in three Cypripedium and three Paphiopedilum species, and quantitatively analyzed their diffusional and biochemical limitations to photosynthesis. Paphiopedilum species showed lower light-saturated photosynthetic rate (A N), stomatal conductance (g s), and mesophyll conductance (g m) than Cypripedium species. A N was positively correlated with g s and g m. And yet, in both species A N was more strongly limited by g m than by biochemical factors or g s. The greater g s of Cypripedium was mainly affected by larger stomatal apparatus area and smaller pore depth, while the less g m of Paphiopedilum was determined by the reduced surface area of mesophyll cells and chloroplasts exposed to intercellular airspace per unit of leaf area, and much thicker cell wall thickness. These results suggest that leaf anatomical structure is the key factor affecting g m, which is largely responsible for the difference in photosynthetic capacity between those two genera. Our findings provide new insight into the photosynthetic physiology and functional diversification of orchids.

Correlated overexpression of metadherin and SND1 in glioma cells.

Glioma is the most common primary brain tumor with poor prognosis. Effective treatment of glioma remains a big challenge due to complex pathogenic mechanisms. Previous studies have shown that metadherin (MTDH) and its interacting protein staphylococcal nuclease domain containing 1 (SND1) are overexpressed in many solid tumors. To elucidate the role of MDTH and SND1 in the pathogenesis of glioma, we examined the expression of MTDH and SND1 in primary glioma tissues and found that both MTDH and SND1 were highly expressed, with similar expression patterns. Co-expression of MTDH and SND1 was associated with advanced glioma grades. In addition, we detected the interaction between MTDH and SND1 in cultured glioma cell lines. MTDH could promote the expression of p65 and SND1 in glioma cells. However, enhanced SND1 expression by MTDH was abolished by the inhibition of p65. In conclusion, we demonstrated high expression levels MTDH and SND1 in primary glioma tissues. MTDH might promote glioma by inducing SND1 expression through the activation of NF-κB pathway. MTDH and SND1 may serve as the indicator of malignancy and prognosis as well as therapeutic targets for patients with glioma.

Oncolytic virus-mediated tumor radiosensitization in mice through DNA-PKcs-specific shRNA.

One of the key issues in cancer radiotherapy research is to sensitize tumor cells to the cell killing effects of ionizing radiation while leaving normal tissues intact. One potential approach to achieve this is through tumor-specific targeting of DNA repair genes. In this study, we engineered a replication-deficient adenovirus encoding a mini shRNA gene targeted to the DNA-PKcs gene, which is involved in double strand break DNA repair, and evaluated its anti-tumor efficacy in combination with radiotherapy. Our shRNA-encoding adenovirus showed significant efficacy in down-regulating the levels of the DNA-PKcs protein that was accompanied by increased radiation sensitivity in the human HCT116 colon cancer cells. However, when delivered intratumorally to xenograft human tumors, minimal anti-tumor effects of the virus were seen either alone or in combination with radiation therapy, suggesting an inefficiency of the non-replicative adenovirus in delivering shRNA genes to the tumor mass. When a conditionally replicative adenovirus targeted to telomerase-positive tumor cells was used in conjunction with the DNA-PKcs-targeted shRNA-encoding non-replicative adenovirus, the efficiency of tumor-specific anti-DNA-PKcs shRNA gene expression was enhanced significantly. Most importantly, this enhanced shRNA expression led to significant anti-tumor efficacy of concurrently delivered radiation therapy. Our results suggest our shRNA-based DNA-PKcs- targeting approach in combination with tumor-targeting replicative adenovirus is a promising method to sensitize solid tumors to radiation therapy.

Proteomic characterization of the cellular response to nitrosative stress mediated by s-nitrosoglutathione reductase inhibition.

The S-nitrosoglutathione-metabolizing enzyme, GSNO reductase (GSNOR), has emerged as an important regulator of protein S-nitrosylation. GSNOR ablation is protective in models of asthma and heart failure, raising the idea that GSNOR inhibitors might hold therapeutic value. Here, we investigated the effects of a small molecule inhibitor of GSNOR (GSNORi) in mouse RAW 264.7 macrophages. We found that GSNORi increased protein S-nitrosylation in cytokine-stimulated cells, and we utilized stable isotope labeling of amino acids in cell culture (SILAC) to quantify the cellular response to this "nitrosative stress". The expression of several cytokine-inducible immunomodulators, including osteopontin, cyclooxygenase-2, and nitric oxide synthase isoform 2 (NOS2), were decreased by GSNORi. In addition, selective targets of the redox-regulated transcription factor, nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-including heme oxygenase 1 (HO-1) and glutamate cysteine ligase modulatory subunit-were induced by GSNORi in a NOS2- and Nrf2-dependent manner. In cytokine-stimulated cells, Nrf2 protected from GSNORi-induced glutathione depletion and cytotoxicity and HO-1 activity was required for down-regulation of NOS2. Interestingly, GSNORi also affected a marked increase in NOS2 protein stability. Collectively, these data provide the most complete description of the global effects of GSNOR inhibition and demonstrate several important mechanisms for inducible response to GSNORi-mediated nitrosative stress.

S-nitrosoglutathione supplementation to ovalbumin-sensitized and -challenged mice ameliorates methacholine-induced bronchoconstriction.

S-nitrosoglutathione (GSNO) is an endogenous bronchodilator present in micromolar concentrations in airway lining fluid. Airway GSNO levels decrease in severe respiratory failure and asthma, which is attributable to increased metabolism by GSNO reductase (GSNOR). Indeed, we have found that GSNOR expression and activity correlate inversely with lung S-nitrosothiol (SNO) content and airway hyperresponsiveness (AHR) to methacholine (MCh) challenge in humans with asthmatic phenotypes (Que LG, Yang Z, Stamler JS, Lugogo NL, Kraft M. Am J Respir Crit Care Med 180: 226-231, 2009). Accordingly, we hypothesized that local aerosol delivery of GSNO could ameliorate AHR and inflammation in the ovalbumin-sensitized and -challenged (OVA) mouse model of allergic asthma. Anesthetized, paralyzed, and tracheotomized 6-wk-old male control and OVA C57BL/6 mice were administered a single 15-s treatment of 0-100 mM GSNO. Five minutes later, airway resistance to MCh was measured and SNOs were quantified in bronchoalveolar lavage (BAL). Duration of protection was evaluated following nose-only exposure to 10 mM GSNO for 10 min followed by measurements of airway resistance, inflammatory cells, and cytokines and chemokines at up to 4 h later. Acute delivery of GSNO aerosol protected OVA mice from MCh-induced AHR, with no benefit seen above 20 mM GSNO. The antibronchoconstrictive effects of GSNO aerosol delivered via nose cone were sustained for at least 4 h. However, administration of GSNO did not alter total BAL cell counts or cell differentials and had modest effects on cytokine and chemokine levels. In conclusion, in the OVA mouse model of allergic asthma, aerosolized GSNO has rapid and sustained antibronchoconstrictive effects but does not substantially alter airway inflammation.