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BackgroundShip engine emissions are important with regard to lung and cardiovascular diseases especially in coastal regions worldwide. Known cellular responses to combustion particles include oxidative stress and inflammatory signalling.ObjectivesTo provide a molecular link between the chemical and physical characteristics of ship emission particles and the cellular responses they elicit and to identify potentially harmful fractions in shipping emission aerosols.MethodsThrough an air-liquid interface exposure system, we exposed human lung cells under realistic in vitro conditions to exhaust fumes from a ship engine running on either common heavy fuel oil (HFO) or cleaner-burning diesel fuel (DF). Advanced chemical analyses of the exhaust aerosols were combined with transcriptional, proteomic and metabolomic profiling including isotope labelling methods to characterise the lung cell responses.ResultsThe HFO emissions contained high concentrations of toxic compounds such as metals and polycyclic aromatic hydrocarbon, and were higher in particle mass. These compounds were lower in DF emissions, which in turn had higher concentrations of elemental carbon (“soot”). Common cellular reactions included cellular stress responses and endocytosis. Reactions to HFO emissions were dominated by oxidative stress and inflammatory responses, whereas DF emissions induced generally a broader biological response than HFO emissions and affected essential cellular pathways such as energy metabolism, protein synthesis, and chromatin modification.ConclusionsDespite a lower content of known toxic compounds, combustion particles from the clean shipping fuel DF influenced several essential pathways of lung cell metabolism more strongly than particles from the unrefined fuel HFO. This might be attributable to a higher soot content in DF. Thus the role of diesel soot, which is a known carcinogen in acute air pollution-induced health effects should be further investigated. For the use of HFO and DF we recommend a reduction of carbonaceous soot in the ship emissions by implementation of filtration devices.

We compared the inflammatory and cytotoxic responses caused by household mold and bacteria in human and mouse cell lines. We studied the fungi Aspergillus versicolor, Penicillium spinulosum, and Stachybotrys chartarum and the bacteria Bacillus cereus, Pseudomonas fluorescens, and Streptomyces californicus for their cytotoxicity and ability to stimulate the production of inflammatory mediators in mouse RAW264.7 and human 28SC macrophage cell lines and in the human A549 lung epithelial cell line in 24-hr exposure to 10(5), 10(6), and 10(7) microbes/mL. We studied time dependency by terminating the exposure to 10(6) microbes/mL after 3, 6, 12, 24, and 48 hr. We analyzed production of the cytokines tumor necrosis factor-alpha and interleukins 6 and 1ss (TNF-alpha, IL-6, IL-1ss, respectively) and measured nitric oxide production using the Griess method, expression of inducible NO-synthase with Western Blot analysis, and cytotoxicity with the MTT-test. All bacteria strongly induced the production of TNF-alpha, IL-6 and, to a lesser extent, the formation of IL-1ss in mouse macrophages. Only the spores of Str. californicus induced the production of NO and IL-6 in both human and mouse cells. In contrast, exposure to fungal strains did not markedly increase the production of NO or any cytokine in the studied cell lines except for Sta. chartarum, which increased IL-6 production somewhat in human lung epithelial cells. These microbes were less cytotoxic to human cells than to mouse cells. On the basis of equivalent numbers of bacteria and spores of fungi added to cell cultures, the overall potency to stimulate the production of proinflammatory mediators decreased in the order Ps. fluorescens > Str. californicus > B. cereus > Sta. chartarum > A. versicolor > P. spinulosum. These data suggest that bacteria in water-damaged buildings should also be considered as causative agents of adverse inflammatory effects.

RAW 264.7 macrophages, when challenged with a combination of lipopolysaccharide (10 g/ml) and interferon-␥ (100 units/ml), respond with endogenous NO ⅐ formation, which ultimately results in apoptotic cell death. Apoptosis is detected morphologically by chromatin condensation. Concomitantly we noticed the accumulation of the tumor suppressor protein p53. NO ⅐ -derived apoptosis was blocked by the NO ⅐ -synthase inhibitor N Gmonomethyl-L-arginine. Repetitive treatment of RAW 264.7 macrophages with lipopolysaccharide/interferon-␥, followed by subculturing viable cells, allowed us to select resistant macrophages which we called RES. RES cells still produced comparable amounts of nitrite/nitrate in response to agonist treatment but showed no apoptotic markers, i.e. chromatin condensation or p53 accumulation. However, RES macrophages undergo apoptosis in the presence of exogenously supplied NO ⅐ , released from the NO-donors S-nitrosoglutathione or spermine-NO. Assessment of cytochrome c reduction established that RES cells released twice the amount of superoxide compared to RAW 264.7 macrophages under both resting and stimulated conditions. We linked increased superoxide production to cellular macrophage resistance by demonstrating decreased apoptosis after simultaneous application of S-nitrosoglutathione or spermine-NO and the redox cycler 2,3-dimethoxy-1,4-naphthoquinone. Our results suggest that macrophage resistance toward NO ⅐ -mediated apoptosis is, at least in part, due to increased superoxide formation. Therefore, the balance between reactive nitrogen and reactive oxygen species regulates RAW 264.7 macrophage apoptosis.Nitric oxide (NO) 1 is recognized for its participation in diverse biological processes in nearly all aspects of life (1-3). The formation of NO ⅐ occurs under both physiological and pathophysiological settings. The molecule is synthesized by a family of enzymes termed NO ⅐ synthases (NOS), which utilize arginine as their substrate in the generation of NO ⅐ and stoichiometric amounts of citrulline (4). For convenience, two types of NOS are recognized; constitutive isoforms, which are active for a relatively short time in response to intracellular Ca 2ϩ fluctuations, and a cytokine-inducible isoform. For the latter to be active, mRNA translation and protein synthesis are required. The inducible NOS generates large amounts of NO ⅐ for an extended period. However, once NO ⅐ is produced by the action of NOS, it is extremely susceptible to both oxidation and reduction. This results in the concomitant formation of species with NO ϩ -like activity (nitrosonium ion) or NO Ϫ (nitroxyl anion), respectively (5). In addition to reacting with oxygen, superoxide, and transition metals, NO ⅐ causes biological signaling via interactions with sulfhydryl groups. Because multiple NO surrogates are formed, transduction pathways are classified as either cyclic GMP-dependent or -independent. Cyclic GMP formation is initiated by NO ⅐ binding to the heme group of soluble guanylyl cyclase, thus causing enzyme activati...

Moisture damage in schools may have adverse respiratory health effects in pupils. Finnish school children seem to be at higher risk, possibly due to quantitative and/or qualitative differences in exposure.