Genomic Analysis of Murine Pulmonary Tissue Following Carbonyl Chloride Inhalation

Abstract

Carbonyl chloride (phosgene) is a toxic industrial compound widely used in industry for the production of synthetic products, such as polyfoam rubber, plastics, and dyes. Exposure to phosgene results in a latent (1−24 h), potentially life-threatening pulmonary edema and irreversible acute lung injury. A genomic approach was utilized to investigate the molecular mechanism of phosgene-induced lung injury. CD-1 male mice were exposed whole body to either air or a concentration × time amount of 32 mg/m3 (8 ppm) phosgene for 20 min (640 mg × min/m3). Lung tissue was collected from air- or phosgene-exposed mice at 0.5, 1, 4, 8, 12, 24, 48, and 72 h postexposure. RNA was extracted from the lung and used as starting material for the probing of oligonucleotide microarrays to determine changes in gene expression following phosgene exposure. The data were analyzed using principal component analysis to determine the greatest sources of data variability. A three-way analysis of variance based on exposure, time, and sample was performed to identify the genes most significantly changed as a result of phosgene exposure. These genes were rank ordered by p values and categorized based on molecular function and biological process. Some of the most significant changes in gene expression reflect changes in glutathione synthesis and redox regulation of the cell, including upregulation of glutathione S-transferase α-2, glutathione peroxidase 2, and glutamate-cysteine ligase, catalytic subunit (also known as γ-glutamyl cysteine synthetase). This is in agreement with previous observations describing changes in redox enzyme activity after phosgene exposure. We are also investigating other pathways that are responsive to phosgene exposure to identify mechanisms of toxicity and potential therapeutic targets.

Cholesterol 25-hydroxylase production by dendritic cells and macrophages is regulated by type I interferons

“…Indeed, recent reports from our lab [19,20] and from others [21][22][23] have shown that Ch25h is up-regulated rapidly and significantly in the lungs of mice in response to a pathogen or to a nonpathogen challenge. Although it is clear that Ch25h expression is induced under a variety of conditions, the cellular sources and molecular mechanisms that control this expression are yet to be defined.…”

Air toxics and epigenetic effects: ozone altered microRNAs in the sputum of human subjects

“…Analysis of variance (ANOVA) P values were calculated by using Partek Genomics Suite software (St. Louis, MO). A mixed model two-way ANOVA (13) was used to compare miRNA expression profiles preexposure vs. postexposure by using subject identification as a random effect, similar to microarray analyses performed in previous investigations (32,39). To control the rate of false positives, q-values were calculated as the minimum "false positive discovery rate" that can occur when identifying significant hypotheses (41).…”

Workshop Summary: Phosgene-Induced Pulmonary Toxicity Revisited: Appraisal of Early and Late Markers of Pulmonary Injury From Animal Models With Emphasis on Human Significance

“…-, Data from 10-min exposures were excluded in the concentration-time-response analysis used in the "toxic load model." synthesis of glutathione and redox regulation, arachidonic acid metabolism, the release of proinflammatory cytokines, and cytoskeletal effects (F-actin organization) Franch & Hatch, 1986;Currie et al, 1985Currie et al, , 1987aCurrie et al, , 1987bGhio et al, 2005;Sciuto et al, 2002;Sciuto et al, 2003aSciuto et al, , 2003bSciuto et al, , 2003cSciuto et al, 2005;Duniho et al, 2002;Deshpande et al, 1996;Madden et al, 1991;Werrlein et al, 1994). Phosgeneinduced apoptotic changes in pneumocytes and inflammatory cells were described (Li et al, 2006).…”