Dataset Information

Altered Genomic Expression of Immune and Metabolic Pathways in a Murine Model of Diesel Enhanced Allergic Sensitization

ABSTRACT: Diesel exhaust (DE) has been shown to enhance allergic sensitization in animals following high dose instillation or chronic inhalation exposure scenarios. The purpose of this study was to determine if short term exposures to diluted DE enhance allergic immune responses to antigen, and identify possible mechanisms using microarray technology. BALB/c mice were exposed to filtered air or diluted DE to yield particle concentrations of 500 or 2000 µg/m3 4 hr/day on days 0-4. Mice were sensitized intranasally with ovalbumin (OVA) antigen or saline on days 0-2, and 18 and all were challenged with OVA on day 28. Mice were necropsied either 4 hrs after the last DE exposure on day 4, or 18, 48, and 96 hrs after challenge. Immunological endpoints included OVA-specific serum IgE, biochemical and cellular profiles of bronchoalveolar lavage (BAL), and cytokine production in the BAL. OVA-sensitized mice exposed to both concentrations of DE had increased eosinophils, neutrophils, lymphocytes, and IL-6 post-challenge compared to OVA control, while DE/saline exposure yielded increases in neutrophils at the high dose only. Microarray analysis demonstrated distinct gene expression profiles for the high dose DE/OVA and DE/saline groups. DE/OVA induced pathways involved in oxidative stress and metabolism while DE in the absence of allergen sensitization modulated cell cycle control, growth and differentiation, G-proteins, and cell adhesion pathways. This study shows for the first time early changes in gene expression induced by the combination of diesel exhaust inhalation and antigen sensitization, which resulted in stronger development of an allergic asthma phenotype. Keywords: dose response

ORGANISM(S): Mus musculus

PROVIDER: GSE9383 | GEO | 2008/03/26

SECONDARY ACCESSION(S): PRJNA103097

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:There is an emerging concern that particulate air pollution increases the risk of cranial nerve disease onset. Small nanoparticles, mainly derived from diesel exhaust particles reach the olfactory bulb by their nasal depositions. It has been reported that diesel exhaust inhalation causes inflammation of the olfactory bulb and other brain regions. However, these toxicological studies have not evaluated animal rearing environment. We hypothesized that rearing environment can change mice phenotypes and thus might alter toxicological study results. In this study, we exposed mice to diesel exhaust inhalation at 90 micro g/m3, 8 hours/day, for 28 consecutive days after rearing in a standard cage or environmental enrichment conditions. Microarray analysis found that expression levels of 112 genes were changed by diesel exhaust inhalation. Functional analysis using Gene Ontology revealed that the dysregulated genes were involved in inflammation and immune response. This result was supported by pathway analysis. Quantitative RT-PCR analysis confirmed 10 genes. Interestingly, background gene expression of the olfactory bulb of mice reared in a standard cage environment was changed by diesel exhaust inhalation, whereas there was no significant effect of diesel exhaust exposure on gene expression levels of mice reared with environmental enrichment. The results indicate for the first time that the effect of diesel exhaust exposure on gene expression of the olfactory bulb was influenced by rearing environment. Rearing environment, such as environmental enrichment, may be an important contributive factor to causation in evaluating still undefined toxic environmental substances such as diesel exhaust. RNA sample was taken from olfactory bulb of 56-day-old mouse received diesel exhaust (DE) inhalation at 90 micro g/m3, 8 hours/day, for 28 consecutive days, while control RNA was taken from mouse received clean air, after rearing in a standard cage or environmental enrichment conditions. Comparisons among groups were made by one-color method with normalized data from Cy3 channels for data analysis.

Project description:Background: Epidemiologic associations between acutely increased cardiorespiratory morbidity and mortality and particulate air pollution are well-established, but the effects of acute pollution exposure on human gene expression changes are not well understood. Objectives: In order to identify potential mechanisms underlying epidemiologic associations between air pollution and morbidity, we explored changes in gene expression in humans following inhalation of fresh diesel exhaust (DE), a model for particulate air pollution. Methods: 14 ethnically homogeneous (white males), young, healthy subjects underwent sixty minute inhalation exposures on 2 separate days with clean air (CA) or freshly generated and diluted DE at a concentration of 300 Î¼g/m3 PM2.5. Prior to and 24 hours following each session, whole blood was sampled and fractionated for PBMC isolation, RNA extraction, and generation of cDNA, followed by hybridizationÂ withÂ Agilent Whole Human Genome (4X44K) arrays. Results: Oxidative stress and the ubiquitin proteasome pathway, as well as the coagulation system, were among hypothesized pathways identified by analysis of differentially expressed genes. Nine genes from these pathways were validated using real-time PCR comparing fold change in expression between DE exposed and clean (CA) days. Quantitative gene fold changes generated by real-time PCR were consistent with the directional fold changes from the microarray analysis. Conclusions: Changes in gene expression connected with key oxidative stress, protein degradation, and coagulation pathways are likely to underlie observed physiologic and clinical outcomes and suggest specific avenues and sensitive time points for further physiologic exploration. Diesel exhaust inhalation exposure-induced human gene expression changes were measured in peripheral blood mononuclear cells. 14 white males subjects were seated in a controlled environment facility for 2 separate 60 minute inhalation exposures which occurred at least 1 week apart to either clean air and freshly generate or diluted diesel exhaust (300ug/m3 PM2.5) .Blood collection occurred immediately prior to and 24 hours following exposures. Two microarrays per subject were completed using Agilent Whole Human Genome (4X44K) arrays. Genes that were of interest to our research group were verified using Real Time PCR analysis.

Dataset Information

Altered Genomic Expression of Immune and Metabolic Pathways in a Murine Model of Diesel Enhanced Allergic Sensitization

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets