Project description:Adiponectin is an adipose-derived hormone with anti-inflammatory activity. Following subacute ozone exposure (0.3 ppm for 24-72 h), pulmonary neutrophilic inflammation is augmented in adiponectin deficient mice. The purpose of this study was to use microarrays to examine the impact of adiponectin deficiency on changes in pulmonary gene expression induced by ozone, a common air pollutant.
Project description:Adiponectin is an adipose-derived hormone with anti-inflammatory activity. Following subacute ozone exposure (0.3 ppm for 24-72 h), pulmonary neutrophilic inflammation is augmented in adiponectin deficient mice. The purpose of this study was to use microarrays to examine the impact of adiponectin deficiency on changes in pulmonary gene expression induced by ozone, a common air pollutant. Lungs were harvested from wildtype and mice that were genetically deficient in adiponectin. Mice were exposed either to room air or to ozone (0.3 ppm) for 72 h. RNA was extracted and microarray analysis of gene expression performed. Both male and female mice were used.
Project description:Rationale: Previous work demonstrated that pre-exposure to ozone primes innate immunity and increases TLR4-mediated response to subsequent stimulation with lipopolysaccharide (LPS). To further explore the pulmonary innate immune response to ozone exposure, we investigated the effect of ozone in combination with Pam3CYS, a synthetic TLR2/TLR1 agonist. Methods: Bronchoalveolar lavage (BAL) and lungs were harvested from C57Bl/6 mice after exposure to ozone or filtered air followed by saline or Pam3CYS 24 hours later. Cells and cytokines in the BAL, surface expression of TLRs on macrophages, and lung RNA genomic expression profiles were examined. Results: We demonstrate an increased BAL cell influx, increased IL-6 and KC, and decreased MIP-1α and TNF-α in response to Pam3CYS as a result of ozone pre-exposure. We also observed increased cell surface expression of TLR4, TLR2 and TLR1 on macrophages as a result of ozone alone or in combination with Pam3CYS. Gene expression analysis of lung tissue revealed a significant increase in expression of genes related to injury repair and cell cycle as a result of ozone exposure. When comparing Pam3CYS treated animals to saline treated animals with or without ozone, genes associated with inflammation were significantly increased. Potentially novel ozone exposure candidate genes (CCK, RELM-α and β) were identified. Conclusion: Our results extend previous findings with ozone/LPS to other TLRs PAMPs and suggest that ozone priming of innate immunity is a general mechanism. Gene expression profiling of lung tissue identified transcriptional networks and genes that contribute to the priming of innate immunity at the molecular level. Mice were exposed to either 2ppm ozone or filtered air (FA) for 3 hours. 24 hours following ozone exposure, mice from either the ozone or FA group were treated intratracheally with either 100ug of Pam3CYS in saline or saline alone. Animals were euthanized 4 or 24 hours post-Pam3CYS exposure. RNA from whole lung tissue from 4 animals per group was profiled.
Project description:Rationale: Previous work demonstrated that pre-exposure to ozone primes innate immunity and increases TLR4-mediated response to subsequent stimulation with lipopolysaccharide (LPS). To further explore the pulmonary innate immune response to ozone exposure, we investigated the effect of ozone in combination with Pam3CYS, a synthetic TLR2/TLR1 agonist. Methods: Bronchoalveolar lavage (BAL) and lungs were harvested from C57Bl/6 mice after exposure to ozone or filtered air followed by saline or Pam3CYS 24 hours later. Cells and cytokines in the BAL, surface expression of TLRs on macrophages, and lung RNA genomic expression profiles were examined. Results: We demonstrate an increased BAL cell influx, increased IL-6 and KC, and decreased MIP-1α and TNF-α in response to Pam3CYS as a result of ozone pre-exposure. We also observed increased cell surface expression of TLR4, TLR2 and TLR1 on macrophages as a result of ozone alone or in combination with Pam3CYS. Gene expression analysis of lung tissue revealed a significant increase in expression of genes related to injury repair and cell cycle as a result of ozone exposure. When comparing Pam3CYS treated animals to saline treated animals with or without ozone, genes associated with inflammation were significantly increased. Potentially novel ozone exposure candidate genes (CCK, RELM-α and β) were identified. Conclusion: Our results extend previous findings with ozone/LPS to other TLRs PAMPs and suggest that ozone priming of innate immunity is a general mechanism. Gene expression profiling of lung tissue identified transcriptional networks and genes that contribute to the priming of innate immunity at the molecular level.
Project description:Ozone is a common pollutant and a potent oxidant in industrialized nations. The mechanisms of ozone-induced lung injury and differential susceptibility are not fully understood. Ozone-induced lung inflammation is mediated, in part, by the innate immune system. We hypothesized that mannose binding lectin (MBL), which has a central role in the activation of the complement pathway of innate immunity, is a necessary component of the pro-inflammatory events caused by ozone-mediated activation of the innate immune system. Wild-type (Mbl+/+) and MBL deficient (Mbl-/-) mice were exposed to ozone (0.3 ppm) for 24, 48, and 72 hours, and bronchoalveolar lavage fluid (BALF) was examined for inflammatory markers. Compared to Mbl+/+ mice, significantly greater mean BALF eosinophils, neutrophils and neutrophil attractants CXCL2 (MIP-2) and CXCL5 (LIX) were found in Mbl-/- mice exposed to ozone. Using genome-wide mRNA microarray analyses, we identified significant differences in expression response profiles and networks at baseline (e.g. NRF2 mediated oxidative stress response) and after exposure (e.g. humoral immune response) between Mbl+/+ and Mbl-/- mice. The microarray data were further analyzed using a pattern recognition analysis for Extracting Patterns and Identifying co-expressed Genes (EPIG), and discovered several informative differential response patterns and subsequent gene sets, including antimicrobial response and inflammatory response. These novel findings demonstrate that targeted deletion of Mbl caused differential expression of inflammation-related gene sets basally and after exposure to ozone, and significantly reduced pulmonary inflammation thus indicating an important innate immunomodulatory role of the gene in this model.
Project description:Fish oil, olive oil, and coconut oil dietary supplementation have several cardioprotective benefits, but it is not established if they can protect against air pollution-induced adverse effects. We hypothesized that these dietary supplements would attenuate ozone-induced systemic and pulmonary effects. Male Wistar Kyoto rats were fed either a normal diet, or a diet enriched with fish, olive, or coconut oil starting at 4 weeks of age for 8 weeks. Animals were then exposed to air or ozone (0.8 ppm), 4h/day for 2 consecutive days. The fish oil diet completely abolished phenylephrine-induced vasoconstriction that was increased following ozone exposure in the animals fed all other diets. Only the fish oil diet increased baseline levels of bronchoalveolar lavage fluid (BALF) markers of lung injury and inflammation. Ozone-induced pulmonary injury/inflammation were comparable in rats on normal, coconut oil, and olive oil diets with altered expression of markers in animals fed the fish oil diet. Fish oil, regardless of exposure, led to enlarged, foamy macrophages in the BALF that coincided with decreased mRNA expression of cholesterol transporters, cholesterol receptors, and nuclear receptors in the lung. Serum miRNA profile was assessed using small RNA-sequencing in normal and fish oil groups and demonstrated marked depletion of a variety of miRNAs, several of which were of splenic origin. No ozone-specific changes were noted. Collectively, these data indicate that while fish oil offered protection from ozone-induced aortic vasoconstriction, it increased pulmonary injury/inflammation and impaired lipid transport mechanisms resulting in foamy macrophage accumulation, demonstrating the need to be cognizant of potential off-target pulmonary effects that might offset the overall benefit of this vasoprotective dietary supplement.
Project description:Acute exposure to inhaled ozone causes oxidative stress, lung injury, and inflammation. Activated macrophages play a key role in both the initiation and resolution of the inflammatory response to inhaled ozone; this activity is mediated by distinct subsets, broadly classified as proinflammatory (M1) and anti-inflammatory/pro-resolution (M2) macrophages. Successful resolution of inflammation and tissue repair require balanced activity of M1 and M2 macrophages. In this context, overactivation of M1 macrophages or inadequate activation of M2 macrophages results in a failure to resolve inflammation and prolonged injury. Thus, identifying signaling mechanisms contributing to aberrant activation of lung macrophages is critical to mitigating lung injury and decrements in pulmonary function caused by this ubiquitous air pollutant. The purpose of the present study was to identify mechanisms regulating macrophage activation in response to acute exposure to ozone by characterizing global transcriptional profiles using RNA-seq. We hypothesized that gene expression patterns would be distinctly regulated at 24 and 72 hr post exposure to ozone as these time points reflect different phases of the inflammatory response, namely initiation and resolution, when macrophage subpopulations derived from different origins would predominate. We identified significant enrichment of pathways involved in innate immune signaling and cytokine production among differentially expressed genes at 24 and 72 hr post exposure. In addition, we observed a preponderance of pathways involved in cell cycle regulation at 24 hr and intracellular metabolism at 72 hr post exposure. These studies are significant as they permit the identification of signaling pathways representing prospective therapeutic targets to fine tune macrophage responses and limit ozone-induced lung injury.
Project description:Ozone is a major air pollutant in highly populated areas. High levels of ambient ozone have been associated with decreased lung function and increased exacerbations of asthma in children and adults. However, the effects of ozone on the newborn’s lung are largely unknown. This study was aimed at profiling the newborn lung response to ozone at the transcriptome level to define the impact of ozone pollutant on the developing postnatal lung. Newborn mice were exposed to ozone or filtered normal air for 3 h. Total RNA was isolated from lung tissues at 6 and 24 h after completion of exposure and was subjected to gene expression analysis using Whole Mouse Genome Gene Expression 4X44K Microarrays (G2519F-014868, Agilent Technologies). Transcriptome analysis of the postnatal lung indicated that 455 genes were down-regulated and 166 genes were up-regulated by at least 1.5 fold at 6 h post-ozone exposure (t-test, p<0.05). At 24 h post exposure, 543 genes were down-regulated and 323 genes were up-regulated in the lungs of ozone-exposed newborn mice, compared to filtered air-exposed newborn mice (t-test, p<0.05). After controlling for false discovery rate, 50 genes were significantly down-regulated and only 4 genes were up-regulated at 24 h post ozone-exposure (q<0.05). Gene ontology enrichment analysis revealed that cell cycle-associated functions including cell division/proliferation, cellular assembly and organization were the predominant pathways negatively regulated by ozone exposure. These findings suggest that elevated ozone pollution may interfere with lung development and growth in the early age.
Project description:Oxidative stress caused by ground level ozone is a major contributor to yield loss in a number of important crop plants. Soybean (Glycine max) is especially ozone sensitive, and research into its response to oxidative stress is limited. To better understand the genetic response in soybean to oxidative stress, an RNA-seq analysis of two soybean cultivars was performed comparing an ozone intolerant cultivar and an ozone resistant cultivar after being exposed to ozone. A cursory analysis of the transcriptome data revealed differences between cultivars in the expression levels of genes previously implicated in oxidative stress responses, indicating unique cultivar-specific responses. An examination of the timing of gene responses over the course of ozone exposure showed expression of cuticle wax genes in the intolerant line over all sampled time points, whereas the tolerant line only expressed this pathway in the first time point. The ozone tolerant cultivar has a thicker leaf structure and we believe this lends a passive benefit to the plant which the intolerant cultivar is attempting to supplement via cuticle wax synthesis. These results suggest that differences in genetic responses work in concert with physiological differences to explain differences in ozone tolerance between soybean cultivars.
Project description:Ozone is a major air pollutant in highly populated areas. High levels of ambient ozone have been associated with decreased lung function and increased exacerbations of asthma in children and adults. However, the effects of ozone on the newbornM-bM-^@M-^Ys lung are largely unknown. This study was aimed at profiling the newborn lung response to ozone at the transcriptome level to define the impact of ozone pollutant on the developing postnatal lung. Newborn mice were exposed to ozone or filtered normal air for 3 h. Total RNA was isolated from lung tissues at 6 and 24 h after completion of exposure and was subjected to gene expression analysis using Whole Mouse Genome Gene Expression 4X44K Microarrays (G2519F-014868, Agilent Technologies). Transcriptome analysis of the postnatal lung indicated that 455 genes were down-regulated and 166 genes were up-regulated by at least 1.5 fold at 6 h post-ozone exposure (t-test, p<0.05). At 24 h post exposure, 543 genes were down-regulated and 323 genes were up-regulated in the lungs of ozone-exposed newborn mice, compared to filtered air-exposed newborn mice (t-test, p<0.05). After controlling for false discovery rate, 50 genes were significantly down-regulated and only 4 genes were up-regulated at 24 h post ozone-exposure (q<0.05). Gene ontology enrichment analysis revealed that cell cycle-associated functions including cell division/proliferation, cellular assembly and organization were the predominant pathways negatively regulated by ozone exposure. These findings suggest that elevated ozone pollution may interfere with lung development and growth in the early age. Three-day old BALB/c mice were exposed for 3 h to ozone (1000 parts per billion). Age-matching littermate controls were exposed for 3 h to filtered normal air. Whole lung tissue was collected 6 and 24 h after completion of exposure to ozone or filtered air and was subjected to microarray analysis. Each time point was performed separately with its own filtered air littermate controls. Pups were cross-fostered during exposure so that all pups were with a dam during exposure. A total of 6-8 mice were initially included in each group and time point. Of these, n=4 mouse lungs were randomly selected for use in gene expression analysis.