ABSTRACT: The lung response to inhalation exposure to oil vapor particles was investigated in a rat model. Adult male Sprague-Dawley rats were exposed by whole-body inhalation to air or an aerosol containing oil vapor particles at concentrations of 300 ppm, 6 hours/day for 1 day (shot-term) or 300 ppm, 6 hours/day, 4 days/week for 4 weeks (long-term). The control and oil vapor exposed rats were euthanized at post-exposure time intervals of 1 and 28 days and lung toxicity determined. Analysis of bronchoalveolar lavage parameters of toxicity such as lactate dehydrogenase activity, oxidant generation, and inflammation did not reveal any significant lung toxicity in the oil vapor exposed rats. Approximately 50 genes each were found significantly differentially expressed in both the short- and long-term exposure groups of the rats at the one-day post-exposure time interval. The data obtained from the present study demonstrated that oil vapor inhalation exposure, under the exposure conditions employed in the present study, did not result in any significant lung toxicity in the rats despite the gene expression changes detected.
Project description:Cigarette smoking causes serious diseases, including lung cancer, heart disease, and emphysema. While cessation remains the most effective approach to minimize smoking-related disease, alternative non-combustible tobacco-derived nicotine containing products may reduce disease risks among those unable or unwilling to quit. E-vapor aerosols typically contain significantly lower levels of smoke-related harmful and potentially harmful constituents; however, health risks of long-term inhalation exposures are unknown. We designed a 7-month inhalation study in C57BL/6 mice to evaluate long-term respiratory toxicity of e-vapor aerosols compared to cigarette smoke and to assess the impact of smoking cessation or switching to an e-vapor product after 3 months of exposure to 3R4F cigarette smoke (CS). There were no significant changes in in-life observations (body weights, clinical signs) in e-vapor groups compared to the Sham Control. The 3R4F CS group showed reduced respiratory function during exposure and had lower body weight and showed transient signs of distress post-exposure. Following 7 months of exposure, e-vapor aerosols resulted in no or minimal increase in pulmonary inflammation, while exposure to 3R4F CS led to impairment of lung function and caused marked lung inflammation and emphysematous changes. Biological changes observed in the Switching group were similar to the Cessation group. 3R4F CS exposure dysregulated lung and nasal tissue transcriptome, while these molecular effects were substantially lower in the e-vapor group. Results from this study demonstrate that in comparison with 3R4F CS, e-vapor aerosols induce substantially lower biological responses including pulmonary inflammation and emphysema, and that complete switching from CS to e-vapor products significantly reduces biological changes associated with cigarette smoke in C57BL/6 mice.
Project description:The pulmonary response to inhalation exposure to diesel exhaust particles (DEP) was investigated in a rat model. Adult male Sprague-Dawley rats were exposed by whole-body inhalation to air or an aerosol containing DEP at concentrations of 200 or 1000 mg/m3, 6 hours/day for 4 days. The control and DEP-exposed rats were euthanized at post-exposure time intervals of 1, 7, or 27 days and pulmonary inflammatory, cytotoxic and oxidant responses were determined. Analysis of bronchoalveolar lavage parameters of toxicity such as lactate dehydrogenase activity, oxidant generation, and inflammation did not reveal any significant pulmonary toxicity in the DEP-exposed rats. The lung gene expression profiles did not change significantly in the DEP exposed rats compared with the controls. The data obtained from the present study demonstrated that DEP inhalation exposure under the conditions employed in the present study did not result in any significant lung toxicity in the rats.
Project description:The pulmonary inflammatory response to inhalation exposure to fracking sand dust (FSD) was investigated in a rat model. Adult male Sprague-Dawley rats were exposed by whole-body inhalation to air or an aerosol of FSD at concentrations of 10 or 30 mg/m3, 6 hours/day for 4 days. The control and FSD-exposed rats were euthanized at post-exposure time intervals of 1, 7 or 27days and pulmonary inflammatory, cytotoxic and oxidant responses were determined. Deposition of FSD particles was detected in the lungs of all the FSD-exposed rats. Analysis of bronchoalveolar lavage parameters of toxicity, oxidant generation, and inflammation did not reveal any significant persistent pulmonary toxicity in the FSD- exposed rats. Similarly, the lung histology of the FSD-exposed rats showed only minimal changes in influx of macrophages following the exposure. Determination of global gene expression profiles detected significant differential expressions of only six and five genes in the 10 mg/m3, 1 day post-exposure, and the 30 mg/m3, 7-day post-exposure FSD groups, respectively. Taken together, data obtained from the present study demonstrated that FSD inhalation exposure resulted in minimal/no toxicity or gene expression changes in the lungs of the rats.
Project description:The pulmonary response to inhalation exposure to diesel exhaust particles (DEP) and fracking sand particles (FSD) was investigated in a rat model. Healthy adult male Sprague-Dawley rats were exposed by whole-body inhalation to air (control) or an aerosol containing DEP at a concentration of 1.0 mg/m3 combined with FSD at concentrations of 30 mg/m3, 6 hours/day for 4 days. The control and DEP/FSD exposed rats were euthanized at post-exposure time intervals of 1, 7, or 27 days and pulmonary inflammatory, cytotoxic, and oxidant responses were determined. Analysis of bronchoalveolar lavage parameters of toxicity such as lactate dehydrogenase activity, oxidant generation, and inflammation revealed only minimal changes in pulmonary toxicity in the DEP/FSD-exposed rats, compared with the time-matched controls. The lung gene expression profiles showed only minimal changes in the DEP/FSD exposed rats compared with the controls. Specifically, there were a total of 6 genes significantly differentially expressed (fold change >1.5 and FDR p<0.05) only at the one-day post-exposure group. The data obtained from the present study demonstrated that DEP/FSD inhalation exposure, under the conditions employed in the present study, resulted in only minimal changes in lung toxicity and gene expression profile in the rats.
Project description:This data set is #3 of three generated as part of a coordinated series of experiments to examine potential modes of action of Styrene inhalation on lung and liver in male C57Bl/6 mice. Styrene causes increased lung tumors in mice, but not in rats. Mouse lung tumors were found mostly at the conclusion of a life-time (104 weeks for males) exposure study and most were benign. Styrene is largely negative in genotoxicity assays. Styrene metabolism by CYP2F2 produced a different metabolite pattern in mouse lung than in liver or in rats or humans. The purpose of this study was to use genomic analyses to further investigate potential modes of action (MoA) of styrene in mice, using a total of three genomic data sets. Dataset #1 exposed C57BL/6 wild-type (WT), CYP2F2 knockout (-/-; KO) and CYP2F21 humanized (2F2-KO + 2F1,2A13,2B6-transgenic, TG) male mice to 0, 40 or 120 ppm styrene at 6 hr/day 5 days/wk for 1 or 4 wk. Lungs were analyzed by whole genome microarrays for each strain at each dose. The second part of the study examined a broader dose response and short term exposure. Male wild type C57Bl/6 mice were exposed to 6 inhalation concentrations of styrene: 0, 1, 5, 10, 20, 40, and 120 ppm for a single 6 hour exposure. This was intended to gain dose-response data at low-observed-adverse-effect-levels (LOAELs) of styrene (≥ 20 ppm) and at no-observed-adverse-effect-levels (NOAELs) of styrene (< 20 ppm). Dataset #2 examined lung gene expression, while dataset #3 examined liver gene expression data from the same animals.
Project description:This data set is #2 of three generated as part of a coordinated series of experiments to examine potential modes of action of Styrene inhalation on lung and liver in male C57Bl/6 mice. Styrene causes increased lung tumors in mice, but not in rats. Mouse lung tumors were found mostly at the conclusion of a life-time (104 weeks for males) exposure study and most were benign. Styrene is largely negative in genotoxicity assays. Styrene metabolism by CYP2F2 produced a different metabolite pattern in mouse lung than in liver or in rats or humans. The purpose of this study was to use genomic analyses to further investigate potential modes of action (MoA) of styrene in mice, using a total of three genomic data sets. Dataset #1 exposed C57BL/6 wild-type (WT), CYP2F2 knockout (-/-; KO) and CYP2F21 humanized (2F2-KO + 2F1,2A13,2B6-transgenic, TG) male mice to 0, 40 or 120 ppm styrene at 6 hr/day 5 days/wk for 1 or 4 wk. Lungs were analyzed by whole genome microarrays for each strain at each dose. The second part of the study examined a broader dose response and short term exposure. Male wild type C57Bl/6 mice were exposed to 6 inhalation concentrations of styrene: 0, 1, 5, 10, 20, 40, and 120 ppm for a single 6 hour exposure. This was intended to gain dose-response data at low-observed-adverse-effect-levels (LOAELs) of styrene (≥ 20 ppm) and at no-observed-adverse-effect-levels (NOAELs) of styrene (< 20 ppm). Dataset #2 examined lung gene expression, while dataset #3 examined liver gene expression data from the same animals.
Project description:This data set is #1 of three generated as part of a coordinated series of experiments to examine potential modes of action of Styrene inhalation on lung and liver in male C57Bl/6 mice. Styrene causes increased lung tumors in mice, but not in rats. Mouse lung tumors were found mostly at the conclusion of a life-time (104 weeks for males) exposure study and most were benign. Styrene is largely negative in genotoxicity assays. Styrene metabolism by CYP2F2 produced a different metabolite pattern in mouse lung than in liver or in rats or humans. The purpose of this study was to use genomic analyses to further investigate potential modes of action (MoA) of styrene in mice, using a total of three genomic data sets. Dataset #1 exposed C57BL/6 wild-type (WT), CYP2F2 knockout (-/-; KO) and CYP2F21 humanized (2F2-KO + 2F1,2A13,2B6-transgenic, TG) male mice to 0, 40 or 120 ppm styrene at 6 hr/day 5 days/wk for 1 or 4 wk. Lungs were analyzed by whole genome microarrays for each strain at each dose. The second part of the study examined a broader dose response and short term exposure. Male wild type C57Bl/6 mice were exposed to 6 inhalation concentrations of styrene: 0, 1, 5, 10, 20, 40, and 120 ppm for a single 6 hour exposure. This was intended to gain dose-response data at low-observed-adverse-effect-levels (LOAELs) of styrene (≥ 20 ppm) and at no-observed-adverse-effect-levels (NOAELs) of styrene (< 20 ppm). Dataset #2 examined lung gene expression, while dataset #3 examined liver gene expression data from the same animals.
Project description:A 7-month inhalation study in C57BL/6 mice was conducted to evaluate long-term respiratory toxicity of e-vapor aerosols compared to cigarette smoke and to assess the impact of smoking cessation or switching to an e-vapor product after 3 months of exposure to 3R4F cigarette smoke (CS). In this study, we performed a chronic inhalation (4 h/day, 5 d/week, up to 7 months) study in C57BL/6 mice using a commercial (MarkTen®) e-vapor product and a combustible reference cigarette (3R4F) using a Switching and Cessation study design. A commercial e-vapor product (MarkTen® device [version 2.6.8]; “Test Red”) was supplied by Altria Client Services LLC (Richmond, VA, USA). The Test Red formulation was composed of aerosol formers (propylene glycol [PG] and vegetable glycerol [VG]), ~4% nicotine by weight, and flavors (non-menthol). The 3R4F commercial reference cigarettes were purchased from the University of Kentucky (Lexington, KY). HEPA filtered air at the testing facility (Battelle, West Jefferson, OH) was used as Sham Control. General procedures for animal care and housing met the Association for Assessment and Accreditation of Laboratory Animal Care (AAALAC) recommendations and requirements stated in the “Guide for Care and Use of Laboratory Animals” [National Research Council (NRC)] and approved by the Institutional Animal Care and Use Committee (IACUC). Female C57BL/6 mice were received from Charles River Kingston (Stone Ridge, NY). Test atmosphere was generated from smoking machines and delivered to the mice through a nose-only exposure system. The modified Cooperation Centre for Scientific Research Relative to Tobacco (CORESTA) Reference Method 81 regimen (55/30/5: a 55 ± 0.3 mL puff volume, a puff every 30 seconds, a 5-second puff duration) was used to generate e-vapor aerosol for 130 puffs/cartridge. Mainstream smoke from 3R4F cigarette was generated using a modified Health Canada Intense regimen (55/30/2: a 55 ± 0.3 mL puff volume, a puff every 30 seconds, a 2-second puff duration, and a near-square puff profile) for 8 puffs/cigarette. Female C57BL/6 mice (~10 weeks old) were randomly assigned based on body weight to one of five exposure groups: Sham Control, 3R4F CS, Test Red, Switching, and Cessation. Mice were exposed to 3R4F CS (550 µg/L TPM) or e-vapor aerosols (Test Red; 1100 µg/L TPM) via nose-only inhalation up to 4 h/day, 5 d/week for up to 7 months. After the first 3 months of exposure, groups of 3R4F CS mice were subjected to exposures of: (1) Test Red aerosol (“Switching”) or (2) filtered air (“Cessation”), while a group of mice continued to be exposed to 3R4F CS. Here, the protein expression data for lung tissue assessed by iTRAQ®-based quantitative proteomics is reported.
Project description:Lung gene expression after long-term (26 weeks, 52 weeks, 78 weeks & 104 weeks) styrene inhalation exposure at a single concentration (120ppm) in three strains of C57BL/6 mice -- wild-type (WT), CYP2F2 knockout (KO), and CYP2F1 humanized (TG) mice, and CD-1 mice. These data examine transcriptomic changes in lung tissue after long-term styrene inhalation in male C57Bl/6 and CD-1 mice. Styrene causes increased lung tumors in mice, but not in rats. Mouse lung tumors were found mostly at the conclusion of a life-time (104 weeks for males) exposure study and most were benign. Styrene is largely negative in genotoxicity assays. Styrene metabolism by CYP2F2 produced a different metabolite pattern in mouse lung than in liver or in rats or humans. The purpose of this study was to use genomic analyses to further investigate potential modes of action (MoA) of styrene in mice after long-term exposure to styrene. Mice strains exposed were C57BL/6 wild-type (WT), CYP2F2 knockout (-/-; KO) and CYP2F21 humanized transgenic (2F2-KO + 2F1,2A13,2B6-transgenic, TG), and CD-1 male mice using 120 ppm styrene at 6 hr/day 5 days/wk for 26, 52, 78 and 104 weeks. Lungs were analyzed by Affymetrix whole genome microarrays for each strain relative to sample time-specific vehicle controls for each strain.