Metabolic Profiling as Well as Stable Isotope Assisted Metabolic and Proteomic Analysis of RAW 264.7 Macrophages Exposed to Ship Engine Aerosol Emissions: Different Effects of Heavy Fuel Oil and Refined Diesel Fuel

Exposure to air pollution resulting from fossil fuel combustion has been linked to multiple short-term and long term health effects. In a previous study, exposure of lung epithelial cells to engine exhaust from heavy fuel oil (HFO) and diesel fuel (DF), two of the main fuels used in marine engines, led to an increased regulation of several pathways associated with adverse cellular effects, including pro-inflammatory pathways. In addition, DF exhaust exposure was shown to have a wider response on multiple cellular regulatory levels compared to HFO emissions, suggesting a potentially higher toxicity of DF emissions over HFO. In order to further understand these effects, as well as to validate these findings in another cell line, we investigated macrophages under the same conditions as a more inflammationrelevant model. An air-liquid interface aerosol exposure system was used to provide a more biologically relevant exposure system compared to submerged experiments, with cells exposed to either the complete aerosol (particle and gas phase), or the gas phase only (with particles filtered out). Data from cytotoxicity assays were integrated with metabolomics and proteomics analyses, including stable isotope-assisted metabolomics, in order to uncover pathways affected by combustion aerosol exposure in macrophages. Through this approach, we determined differing phenotypic effects associated with the different components of aerosol. The particle phase of diluted combustion aerosols was found to induce increased cell death in macrophages, while the gas phase was found more to affect the metabolic profile. In particular, a higher cytotoxicity of DF aerosol emission was observed in relation to the HFO aerosol. Furthermore, macrophage exposure to the gas phase of HFO leads to an induction of a pro-inflammatory metabolic and proteomic phenotype. These results validate the effects found in lung epithelial cells, confirming the role of inflammation and cellular stress in the response to combustion aerosols

Emissions from a modern log wood masonry heater and wood pellet boiler : Composition and biological impact on air-liquid interface exposed human lung cancer cells

The consumption of wood fuel is markedly increasing in developing and industrialized countries. Known side effects of wood smoke inhalation manifest in proinflammatory signaling, oxidative stress, DNA damage and hence increased cancer risk. In this study, the composition and acute biological impact of emissions of state-of-the-art wood combustion compliances: masonry heater (MH) and pellet boiler (PB) were investigated. Therefore A549 cells were exposed to emission aerosols in an automated air-liquid interface exposure station followed by cytotoxicity, transcriptome and proteome analyses. In parallel, aerosols were subjected to a chemical and physical haracterization. Compared to PB, the MH combustion at the same dilution ratio resulted in a 3-fold higher particle mass concentration (PM2.5) and deposited dose (PB: 27 $\pm$ 2 ng/cm2, MH; 73 $\pm$ 12 ng/cm2). Additionally, the MH aerosol displayed a substantially larger concentration of aldehydes, polycyclic aromatic hydrocarbons (PAH) or oxidized PAH. Gene ontology analysis of transcriptome of A549 cells exposed to MH emissions revealed the activation of proinflammatory response and key signaling cascades MAP kinase and JAK-STAT. Furthermore, CYP1A1, an essential enzyme in PAH metabolism, was induced. PB combustion aerosol activated the proinflammatory marker IL6 and different transport processes. The proteomics data uncovered induction of DNA damage-associated proteins in response to PB and DNA doublestrand break processing proteins in response to MH emissions. Taking together, the MH produces emissions with a higher particle dose and more toxic compounds while causing only mild biological responses. This finding points to a significant mitigating effect of antioxidative compounds in MH wood smoke

Application of time-of-flight mass spectrometry with laser-based photoionization methods for analytical pyrolysis of PVC and tobacco

Application of time-of-flight mass spectrometry with laser-based photoionization methods for analytical pyrolysis of PVC and tobacco / T. Streibel ... - In: Journal of analytical and applied pyrolysis. 74. 2005. S. 454-46

Discrimination of three tobacco types Burley, Virginia and Oriental) by pyrolysis single-photon ionisation–time-of-flight mass spectrometry and advanced statistical methods

Discrimination of three tobacco types Burley, Virginia and Oriental) by pyrolysis single-photon ionisation–time-of-flight mass spectrometry and advanced statistical methods / T. Streibel ... In: Analytical and bioanalytical chemistry. 381. 2005. S. 487-49

Determination of Relative Ionization Cross Sections for Resonance Enhanced Multiphoton Ionization of Polycyclic Aromatic Hydrocarbons

Resonance enhanced multiphoton ionization (REMPI) is a powerful method for the sensitive determination of polycyclic aromatic hydrocarbons (PAHs) in gaseous mixtures via mass spectrometry (MS). In REMPI, ions are produced by the absorption of at least two photons including defined electronic intermediate states. As a result—unlike other laser-based ionization techniques—spectroscopic selectivity is involved into the ionization process. Nevertheless, these wavelength-dependent ionization rates impede the quantification using REMPI. For this purpose, relative photoionization cross sections (relPICS) give an easy-to-use approach to quantify REMPI-MS measurements. Hereby, the ionization behavior of a single compound was compared to that of a reference substance of a given concentration. In this study, relPICS of selected single-core aromatics and PAHs at wavelengths of 266 nm and 248 nm were determined using two different time-of-flight mass spectrometric systems (TOFMS). For PAHs, relPICS were obtained which showed a strong dependence on the applied laser intensity. In contrast, for single-core aromatics, constant values of relPICS were determined. Deviations of relPICS between both TOFMS systems were found for small aromatics (e.g., benzene), which can be assigned to the differences in UV generation in the particular system. However, the relPICS of this study were found to be in good agreement with previous results and can be used for system-independent quantification

Comprehensive chemical description of pyrolysis chars from low-density polyethylene (LDPE) by thermal analysis hyphenated to different mass spectrometric approaches

The production and demand of plastics has drastically increased, with severe environmental impact. Waste incineration is not favored, and efficient recycling strategies are needed. Pyrolysis is a promising approaches but the nature of the residual char is not fully understood. To explore the value of this feedstock, thermal analysis with mass spectrometric detection is deployed. With soft photoionization, we were able to identify alkenes, dienes, and polycyclic aromatic hydrocarbons, which were emitted at four distinct mass loss events. Resonance-enhanced multiphoton ionization allows selectively addressing the aromatic constituents. Interestingly, we found an enrichment of UV-stabilizers, such as benzophenone, within the macromolecular nature. High-resolution mass spectrometry addressing the isobaric complexity and pyrolysis gas chromatography was used for structural elucidation. We hypothesize island- and archipelago-type structural motives comparable to asphaltenes but with almost no heteroatoms. The in-depth chemical description of plastic pyrolysis coke will be valuable knowledge in reactor design and material science

On-Line Process Analysis of Biomass Flash Pyrolysis Gases Enabled by Soft Photoionization Mass Spectrometry

In the current discussion about future energy and fuel supply based on regenerative energy sources, the so-called second-generation biofuels represent a vitally important contribution for the provision of carbon-based fuels. In this framework, at the Karlsruhe Institute of Technology (KIT), the bioliq process has been developed, by which biomass is flash-pyrolyzed at 500 °C for the production of so-called biosyncrude, a suspension of the pyrolysis liquids and the remaining biochar. However, little is known about the composition of the pyrolysis gases in this process with regard to different biomass feedstock and process conditions, and the influence on the subsequent steps, namely, the gasification and subsequent production of biofuels or base materials. Time-of-flight mass spectrometry (TOFMS) with two soft (i.e., fragmentation free) photoionization techniques was for the first time applied for on-line monitoring of the signature organic compounds in highly complex pyrolysis gases at a technical pyrolysis pilot plant at the KIT. Resonance-enhanced multiphoton ionization with TOFMS using UV laser pulses was used for selective and sensitive detection of aromatic species. Furthermore, single-photon ionization using VUV light supplied by an electron beam-pumped excimer light source was used to comprehensively ionize (nearly) all organic molecules. For the miscellaneous biomass feeds used, distinguishable mass spectra with specific patterns could be obtained, mainly exhibiting typical pyrolytic decomposition products of (hemi)­cellulose and lignin (phenol derivatives), and nitrogen-containing compounds in some cases. Certain biomasses are differentiated by their ratios of specific groups of phenolic decomposition products. Therefore, principal component and cluster analysis describes the varied pyrolysis gas composition for temperature variations and particularly for different biomass species. The results can be integrated in the optimization of the bioliq process

An alternative <i>in vitro</i> model considering cell-cell interactions in fiber-induced pulmonary fibrosis

Particularly since the wide-ranging health effects of asbestos exposure became known, great emphasis has been placed on detailed toxicity testing of known but also newly developed fiber materials. Exposure to respirable pollutants like fibers can lead to tissue injury causing lung diseases such as pulmonary fibrosis or cancer. In order to detect the toxic potential of such aerosols at an early stage, the development of suitable test systems is essential. In this study, we illustrate the development of an advanced in vitro cell model closely resembling the physiological structure of the alveoli, and we highlight its advantages over simpler models to predict pro-fibrotic changes. For this reason, we analyzed the cytotoxic effects of fiber-like multi-walled carbon nanotubes after 24 and 48 h exposure, and we investigated inflammatory, genotoxic and pro-fibrotic changes occurring in the developed triple culture consisting of lung epithelial cells, macrophages and fibroblasts compared to a co-culture of epithelial cells and fibroblasts or a mono culture of epithelial cells. In summary, the triple culture system is more precisely able to detect a pro-fibrotic phenotype including epithelial-mesenchymal transition as well as secondary genotoxicity, even if exhibiting lower cytotoxicity in contrast to the less advanced systems. These effects might be traced back to the complex interplay between the different cell types, all of which play an important role in the inflammatory response, which precedes wound healing, or even fibrosis or cancer development.</p