11 Particle-Associated Organics and ProinflammatorySignaling Francelyne Marano, Sonja Boland, and Armelle Baeza-Squiban Laboratoire de CytophysiologieetToxicologie Cellulaire, Universite ´ Paris 7–Denis Dide ` rot CONTENTS 11.1Introduction 211 11.2What Is the Role of These Organic Compounds in the Effects of PM? 211 11.2.1 The Particles OrganicFraction 212 11.2.2 Bioavailability of Organic Compounds 213 11.2.3 Organic Compounds and Oxidative Stress 214 11.2.4 Organic Compounds and Inflammation 216 11.3Conclusion 221 Abbreviations 221 References 221 11.1 INTRODUCTION The burning of fossil fuels generates fine and ultrafineairborneparticles, which contain alarge amount of organic compounds including polyaromatic hydrocarbons(PAH). These particlesmust be takenintoaccount as they are considered to be among themostabundant componentsof particulate matter 2.5 m m(PM 2.5 )inurban areas. Most of them are produced by diesel engine- powered cars and diesel exhaustparticles (DEP) constitute, on average, 40% of the PM 10 in acity such as Los Angeles (Diaz-Sanchez1997), and in akerbside station in Paris more than 50% of particleswereclose to the ultrafine range ( % 0.26 m m), likely due to the influence of the traffic (Baulig et al. 2004). Chemicalanalysis betweenPM 2.5 collectedinakerbside and abackground station in Paris revealed that PAH are twice as important in the kerbside station. The resultsare more relevantwith heavy PAH than light PAH,due to their higherstability. We have also observed variationsofPAH according to the seasons, probably due to chemical reactions with atmospheric oxidants.However, PAH are only apart of the organic component and they do notgreatly influence the soluble organic fraction (SOF) measured after dichloromethane extraction that appeartobe between10and 12% of the massofthe particles whatever the station and approximately 45% lower than the SOF of DEP (20%)(Baulig et al. 2004). 11.2 WHATISTHE ROLE OF THESE ORGANIC COMPOUNDS IN THE EFFECTS OF PM? In this chapter, we do notconsider thegenotoxicand carcinogenic effects of theseorganic compounds. Thedramatic increaseofhumanallergic airway diseasesinthe lastcentury has followed 211 © 2007 by Taylor & Francis Group, LLC the increaseinthe use of fossil fuelsand manyepidemiological studies have provided indirect evidence for acorrelation between particulate pollution andincreasedincidence of asthma and allergicrhinitis.Numerous experimental studies in animals, in human volunteers, and in vitro were performed to provide acausal explanationfor these observations. Diaz-Sanchez et al. have publishednumerous studies on the roleofDEP and their associated PAH in the induction of allergic airwaydiseases(Riedl and Diaz-Sanchez 2005). In vivo nasal provocation studies, usingamounts of DEP equivalent to the total exposure in 1–3 days in Los Angeles, showed enhanced immunoglobulin E(IgE) production in thehuman upperairway.Thisresponseappearstobelinkedtoorganic compounds of DEP sinceithas been established that PAH–DEP could significantly increase IgE mRNA andprotein production in IgE-secretingEpstein–Barr-virus transformedhuman Bcells in vitro (Tsien et al. 1997). The effects of DEP were specific since they do not increaseIgG,IgA, or IgM (Diaz-Sanchez et al. 1994). The ability of DEP to act as an adjuvant was tested by performing nasalprovocationchallengeswithDEP, ragweedantigen Amba1 ,orbothsimultaneously in ragweed-sensitive subjects(Diaz-Sanchez 1997).Ragweed-specific IgEwas 16 timeshigher following ragweed plus DEPchallenge compared with ragweedalone.However,IgG levels remained constant afterchallenge with DEPplusantigen. Furtherexperimentshaveshown an increaseincytokine mRNAlevels such as Interleukin-2(IL-2), IL-4, IL-5, IL-6, and Interferon g . The susceptibility to the adjuvant effect of DEP is an intrinsic trait, as thereisahigh intraindividual reproducibility of the nasal allergic responses in human exposure studies (Bastain et al. 2003). Several candidategenes couldbeinvolved in this susceptibility to particles, such as antioxidant enzymes or Toll Like Receptor 4, CD14 or Tumor Necrosis Factor a (reviewed in Granum and Lovik 2002). This adjuvant effect of DEP for allergic sensitization is adelayed response and does not explain acute PM effects on airwayhyperreactivity. It has been recentlydemonstrated by Hao (Hao et al. 2003), usingBALB/c mouse model sensitized by ovalbumin, that aerosolized DEP could induceincreased airway hyperreactivity even if DEP deliveryisdelayed after the peak inflammatory response. It was concluded that DEP induced airway hyperreactivity independently of adjuvant effects. Interestingly, DEP co-administration with aneoallergen such as keyholelimpethemocyanin showsthat the particles couldsynergize with the neoallergen and drivethe de novo production of antigen-specific IgE (Diaz-Sanchezetal. 1999). These results suggest that DEP exposure with a neoallergen leads to sensitization IgE mucosal production. Thus particulate air pollution may influ- ence both—the sensitization andthe provocation phase of allergybyinducingoxidative and inflammatory reactions in the respiratory mucosa (Granum and Lovik 2002). Moreover, various animal experiments suggest that DEP may alter both innate and acquired cellular immunity. Besidetheir adjuvant effect, these particleshave also an immunosuppressive effect in animals. The increased susceptibility of the lung to infection in rats exposedtoDEP was related to the inhibition of the functions of alveolar macrophages by organic compounds,but not the carbonaceous core (Castranova et al. 2001). Using nitric oxide (NO) production as amarker of macrophage function, it was shownthat crude DEP organic extractsinhibit both Lipopolysac- charide and Bacillus Calmette–Gue ´ rin (BCG) induced NO production by amurine macrophage cell line explaining the impaired bacterial clearance noticed in aBCG mouselung infection model (Saxena et al. 2003b). By fractionation of the organic extract,itappears that this inhibitoryeffect was mainlydue to PAH and resin fractions (Saxena et al. 2003a). Theidentification of the chemical componentsinvolved in thesebiological effects and the understanding of theunderlyingmechanisms are still imperfect. Such studies are difficult,as there exists agreatvariability in the chemical composition of PM according to their emission sources, age, and site of sampling. 11.2.1 T HE P ARTICLES O RGANIC F RACTION The organic fraction of particles comprises acountless quantityofcompounds (such as aliphatic hydrocarbons, PAH, nitroaromatics hydrocarbons, quinones, aldehydes, and heterocyclics), some Particle Toxicology212 © 2007 by Taylor & Francis Group, LLC of which are still unidentified. This fraction can represent up to 50% of the mass of the particle and may contain toxic compounds. At the present time,PAH are quantitatively and qualitatively the best knownfamily of organic compounds adsorbed on particles, although they only represent afew percent of the organic fraction. The interest in these compounds lies in their known genotoxic and inflammatory properties and their use as atracer of source. They have been showntobeinhigher concentrations in submicron particles (DeKok et al. 2005; Rehwagen et al. 2005), which can be explained by the fact that soot from combustion sources consist primarily of fineparticles with high PAH content and that the smaller particleshave arelatively high surface area for PAH adsorption (Ravindra, Mittal, and Van Grieken 2001). Another category of organic compounds that has held the attention of biologists are quinones, due to their ability to induce various hazardous effects in vivo such as acute cytotoxicity,immu- notoxicity, andcarcinogenesis(Bolton et al. 2000). Four quinones(1,2-naphthoquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 9,10-anthraquinone)have been identified and quan- tified in DEP (7.9–4.04 m g/g) and in Los Angeles PM 2.5 (5–730 pg/m 3 )(Cho et al. 2004). 11.2.2 B IOAVAILABILITY OF O RGANIC C OMPOUNDS The presence on particles of organic compounds exhibiting apotential biological effect raises the question of their bioavailablity. To understand the processes whereby particles deliver and transfer toxic components to targetcells,experiments have been doneusing radio-labeled benzo(a)pyrene(B(a)P)-bound denudedparticles.After their administration to dogs,the extentand rate of release as wellastheir metabolic fate wereinvestigated(Gerde et al. 2001b). It reveals that in the alveolar region, B(a)P was adsorbed mostly unaltered into the blood and was systematically metabolized (Gerde et al. 2001a). In the conducting airways, asmaller fraction of B(a)P was slowly deposited but metabolized in the airway epithelium (Gerde et al. 2001b). Nevertheless,alarge fraction of B(a)P remained bound to particleseven 6months after the exposure (Gerde et al. 2001b). In cells, foreign substances are detoxifiedbytwo sequential reaction processes, namely, Phase I and Phase II. In Phase Ireactions, xenobiotics are mainly oxidized by cytochrome P450 (CYP) enzymes to become more polarized metabolites. Phase II metabolism,catalyzed by enzymes such as glutathione S -transferase (GST) and NADP(P)H:quinone oxidoreductase (NQO1),converts the reactive Phase Imetabolites to more hydrophilic substances, allowing their elimination. Among the members of the CYP gene family, CYP1 is knowntobeinduced by PAH through a receptor-dependent mechanism. The cytosolic aryl hydrocarbon receptor (AhR), whenbound by PAH, translocates to the nucleus, heterodimerizes with another partner,and activates the transcrip- tion of CYP1 family genes through binding to the xenobiotic response element. Native DEP, PM and their respective extracts act as activators of the AhR, inducing CYP1A1expressionand activity (Meek 1998; Bonvallot et al. 2001; Baulig et al. 2003a). As showninFigure11.1a, DEP and their organic extract induceatransient CYP1A1mRNA expression in humanbronchial epithelial cells (HBE) similar to B(a)P whereas carbon black particles have not such an effect (Baulig et al. 2003a). The genes of Phase II metabolism (GST,NQO-1) are regulated in aconcerted manner at the transcriptional level through theantioxidant-responsiveelement(ARE)/electrophile-responsive element. The transcription factor NF-E2-related factor-2 (Nrf2) is central to ARE-mediated gene expression (Itohetal. 1997) andNrf2 ( K / K )miceexhibit significantreductionofphase II enzymes (Cho et al. 2002). DEP inducethe translocation of Nrf2 to the nucleus of HBE cells, increasenuclear proteinbinding to the ARE (Baulig et al. 2003a), as well as NQO1expression as shown in Figure11.1b. Whereas this biotransformation process aimed to detoxify xenobiotics, abioactivation may occur and reactive metabolites are produced especially during the Phase I. By this way, PAH give rise to electrophilic metabolitesresponsible for their genotoxicity. Particle-Associated Organics and Proinflammatory Signaling 213 © 2007 by Taylor & Francis Group, LLC Theobservation of the CYP1A1 gene induction in lung homogenates of Big Blue rats exposed,byinhalation,towhole DEPfumes supports theargumentthatthe leachingof organic compounds from particlescan occur (Sato et al. 2000). Moreover,inanother study, it was shown that this transient CYP1A1induction in lungs of rats only occurswith DEP and not with carbon black (Maand Ma 2002). Themechanismsoftransfer of organic compounds from particlestothe target cells can involve the uptake of particles (Bonvallot et al. 2001). However, arecent studyusing fresh butadiene soots suggests that the transfer to cells occurs by the direct contact betweensoots and the plasma membrane, likelyinvolving apartitioning mechanism (Penn et al. 2005). Moreover, it is not known how effectively biological media (e.g., serumorinterstitial fluids) can solubilize the organic compounds (Keane et al. 1991). It has been shown that the addition of surfactant in an aqueoussuspension of DEP or carbon black particles on which aPAH mixture has been previously adsorbed doesn’tfavor the leaching of PAH (Borm et al. 2005). In addition, the PAH bioavailability is negligiblewhenthe PAH content is low relative to the particle monolayer surface (Borm et al. 2005). 11.2.3 O RGANIC C OMPOUNDS AND O XIDATIVE S TRESS Evidence for the involvementofoxidative stress in the effects of organic compounds camefrom theinitial observationthatthe mortalityresultingfromlung edemaafter intratracheal 2h 6h 24 h48h 2.7 1.7 NQO1 DPL DMSO DEP OE-DEP CB BaP DPL DMSO DEP OE-DEP CB BaP DPL DMSO DEP OE-DEP CB BaP DPL DMSO DEP OE-DEP CB BaP 18S 18S 6h 24 h48h DPL DMSO DEP OE-DEP CB BaP DPL DMSO DEP OE-DEP CB BaP DPL DMSO DEP OE-DEP CB BaP DPL DMSO DEP OE-DEP CB BaP CYP1A1 18S 2h (a) (b) FIGURE 11.1 Induction of cytochrome P-450 1A1 (CYP1A1) and NADPH: quinone oxidoreductase 1(NQO- 1) gene expression in HBE cells (a and brespectively). Cells were treated or not with DEP (10 m g/cm 2 ), carbon black (10 m g/cm 2 )organic extracts of DEP (OE-DEP, 10 m g/mL) or benzo(a)pyrene (B(a)P ,3m M). RNA (30 m g) were extracted from cells after 2, 6, 24, or 48 hoftreatment, electrophoresed, Northern-blotted, and then incubated with a 32 P-labeled cDNA probe for CYP1A mRNA, NQO-1 mRNA, or 18S RNA. (From Baulig, A., Garlatti, M., Bonvallot, V., Marchand, A., Barouki, R., Marano, F., and Baeza-Squiban, A., Am. J. Physiol. Lung. Cell. Mol. Physiol.,285, L671–L679, 2003a. With permission). Particle Toxicology214 © 2007 by Taylor & Francis Group, LLC administrationofwhole DEPintomice wassuppressed by pretreatmentwithpolyethylene glycol-modified superoxide dismutase (Sagai et al. 1993) andthatitwas limited with methanol-washed DEP. In this same study, it was shown that in acellularconditions, whole DEP produced oxygen radicals (superoxide anion radical O $K 2 and hydroxyl radical % OH) ident- ified by electron paramagnetic resonance, which were not produced with methanol-washed DEP (Sagai et al. 1993). Quinoneshave been reportedtoberesponsible for this radical production due to their abilitytoundergoenzymatic(P450/P450 reductase) andnon enzymaticredox cycling with their corresponding semiquinone radical giving rise to O $K 2 (Bolton et al. 2000). Further enzymatic or spontaneous dismutation of O $K 2 produces hydrogen peroxide, which in presence of trace amounts of transition metals such as irongives % OH by the Fentonreaction. A methanol extract of DEP has been showntocause asignificant formation of O $K 2 in the presence of Cyt P450 reductase (Kumagai et al. 1997), an enzymewhich activity is increased in DEP- treated mice (Lim et al. 1998). More recently, PM 2.5 have been found to contain abundant and stable semiquinone radicals detected by EPR and to induce DNA damage (Dellinger et al. 2001; Squadrito et al. 2001). To thesesemiquinone radicals directly present on particles, others can be produced during an alternative PAH-metabolizationinvolvingdihydrodiol dehydrogenase leading to thegeneration of PAH o -quinones(Penning et al. 1999). Furthermore, the CYP1A1 catalytic activity generatesreactive oxygen species(ROS) (Perretand Pompon 1998). Redox-active transition metals, redox cycling quinones, and PAH present on PM can act synergistically to produceROS. Taken altogether, thesedata reveal that organic compounds are asourceofROS. It explains the pro-oxidant status measured using various specificfluorescent probesinairwayepithelial cells and macrophages treatedeither with DEP, PM,ortheircorrespondingorganic extract, whereascarbon black particles or solvent-extractedparticlesdonot have such an effect (Hiura et al. 1999; Li et al. 2002; Baulig et al. 2003a; Baulig et al. 2004). Forexample, increased ROS productiondetermined by thedichlorofluorescein fluorescence wasobserved in HBE cells exposedfor 4hto DEP, urban PM 2.5 sampledinParis, and their respective extracts. Theextracts gave afluorescence signal similar to native particles (Figure 11.2). Apro-oxidant status is known to induce cellular specificresponses in the order that cells face oxidant insult. Various studies have shownthatsuchresponses occurinDEP-treated cells. By agenomic approach,the expression profiles of genes induced by organic extractsofDEP in rat alveolar macrophages reveals the increased expression of anti-oxidant enzymes (heme oxygenase (HO-1), thioredoxin peroxidase 2, NADPH dehydrogenase) (Koike et al. 2002; Koike et al. 2004). Similarly, the overexpression of HO-1 was observed in amurine macrophages cell line (RAW264.7) exposed to organic extracts of DEPaswellasinepithelialcells (Lietal. 2002).These data were completed by observation of achange in the proteomeofRAW264.7 exposedtoDEP organic extracts 51 proteins werenewly expressed butweresuppressedby N -acetylcysteine, athiol antioxidant (Xiao et al. 2003). Furthermore, from crude DEP extracts, Li and collaborators (Lietal. 2000)have shown that only the polar fraction that is enrichedinquinones and the aromatic fraction enriched in PAH were able to decrease the cellular GSH/GSSGratio in macrophages as well as to induce HO-1 expression, bothindicative of asituationofoxidative stress. In otherrespects, the comparison of coarse, fine, andultrafinePMrevealed that ultrafine PM have thehighest redox activity(Cho et al. 2005), in agreement with the observation that ultrafines were the most potent towardsinducingHO-1expressionand depleting intracellularGSH (Lietal. 2003). However, thesusceptibility to an adverse health effect of DEPislinkedtothe functionalvariation in naturalantioxidant defenses.The polymorphism of GSTgenes has been associated with atopyand experimental studies provide evidence that the GSTM1and GSTP1 genotypes can play aroleinthe susceptibility to the adjuvant effect of DEP (Gilliland et al. 2004). Particle-Associated Organics and Proinflammatory Signaling 215 © 2007 by Taylor & Francis Group, LLC 11.2.4 O RGANIC C OMPOUNDS AND I NFLAMMATION In vivo human exposure studies show that phenantrene, in contrasttocarbon black, increaseIgE production, butdid notcause inflammatory cell infiltration(Saxonand Diaz-Sanchez2000). In animal studies however PAH not only increased IgE production (Heo,Saxon, and Hankinson 2001)but also the recruitment of inflammatory cells (Hiyoshi et al. 2005). Furthermore, in vitro studies have shown that organic compounds are involved in the proinflammatory response induced by particles in the two respiratory target cells (airway epithelial cells and macrophages).Several studies using HBE cell lines (BEAS-2B,16HBE),normal human airway epithelial cells, and macro- phages have shown that an inflammatory mediator release (IL-8, GM-CSF, RANTES, TNF-a )can be induced by exposure to DEP extract (Boland et al. 2000; Fahy et al. 2000; Li et al. 2002; Vogel et al. 2005). From the comparison of native DEP with their organic extracts obtained with benzene (Kawasaki et al. 2001)ordichloromethane extraction with extracted DEP and carbon blackparticles (Figure 11.3a) (Boland et al. 2000), it was concluded that organic compounds mimic native DEP and that the carbonaceous core is not involved in the proinflammatory response. Moreover,the role of organic compounds was strengthened by the observation that DEP from vehicles equipped with a catalytic converter exhibitingaSOF of 8.3% induce alower GM-CSF releasebyHBE cells than DEPfromnon-equipped vehicles having a35% SOF(Figure 11.3b) (Bolandetal. 2000). Concerning PM, until now, few studies have addressed the involvement of organic compounds. By chemical fractionation (organic vs. aqueous fraction) of Paris urban PM 2.5 ,itwas shown that the GM-CSF secretion induced by native PM 2.5 in HBE cells was mimickedbytheir organic extracts 0 50 DCF fluorescence (% increase relative to control) 100 150 200 250 300 350 400 450 DEP OE-DEP PM OE-PM CB FIGURE 11.2 Dichlorofluorescein (DCF) fluorescence intensity in human bronchial epithelial cells treated with diesel exhaust particles (DEP, 10 m g/cm 2 )ortheir corresponding organic extract (OE-DEP), Paris urban PM 2.5 (PM, 10 m g/cm 2 )ortheir correspondingorganic extract(OE-PM),orcarbonblackparticles (CB, 10 m g/cm 2 ). Thecells were loaded with 2 0 ,7 0 -dichlorofluorescein-diacetate (H2DCF-DA)at20 m Mfor 20 min and then treated or not with the toxics for 4h.The DCF fluorescence was measured by cytometry. Results are expressed in %ofincrease of DCF fluorescence relative to control. Particle Toxicology216 © 2007 by Taylor & Francis Group, LLC whereasthe aqueousextract had aslight effect (Baeza-Squiban et al. 2005). The absence of effect of the soluble fraction was alsoobserved with PM 10 (EHC-93) in normal HBE cells (Fujii et al. 2001). The effect of urban particlesonthe cytokine production of macrophages was also due to the organic fraction (Vogeletal. 2005) (Table 11.1). The induction of chemokine release may be responsible for the inflammatory cell infiltration observedinthe in vivo studies(Hiyoshietal. 2005).Figure11.4 showsthe inflammatory response, which may result from leukocyterecruitment and activation. Beside the stimulation of these inflammatory cells by locally secreted cytokines, it has also been shown that PAH have direct effects on leucocytes. Pyrene increase the production of IL-4 by Tlymphocytes (Bommel et al. 2000)and organic extracts of DEP increase CD1a and costimulatory molecule expression on monocyte derived dendritic cells (Koike and Kobayashi2005), IgE production of Blymphocytes (Takenakaetal. 1995; Tsien et al. 1997),IL-4and histaminerelease frombasophils (Devouassoux et al.2002) as well as mast cell (Diaz-Sanchez, Penichet-Garcia, andSaxon 2000)and eosinophil degranulation (Teradaetal. 1997). This releaseofgranulocyte mediators 100 80 60 40 20 pg of GM-CSF /mL pg of GM-CSF /mL 0 C (a) (b) DEP OE-DEP Extracted DEP Carbon black CDEP -cata OE-DEP -cata DEP +cata OE-DEP +cata 100 120 140 80 60 40 20 0 FIGURE 11.3 GM-CSF release by HBE cells treated for 24 hwith (a) DEP, extracted DEP, or carbon black particles at 10 m g/cm 2 and dichloromethane extracts of DEP (OE-DEP) at 20 m g/mL, (b) DEP collected from adiesel engine with and without an oxidation catalyst and their corresponding organic extracts (OE-DEP). * P ! 0.05compared with control value, B P ! 0.05compared with DEP-treated culture. (From Boland, S., Bonvallot,V., Fournier, T.,Baeza-Squiban,A., Aubier,M., andMarano, F., Am.J.Physiol.LungCell. Mol. Physiol. 278, L25–L32, 2000. With permission). Particle-Associated Organics and Proinflammatory Signaling 217 © 2007 by Taylor & Francis Group, LLC TABLE 11.1 Inflammatory Effects of Organic Compounds In vivo studies in humans CB increase the number of inflammatory cells but NOT IgE Saxon and Diaz-Sanchez (2000) Phenanthrene (with or without allergen) increase IgE but NOT inflammatory cells In vivo studies in animals Mice Phenanthraquinone increase neutrophils,eosinophils, IL-5 and eotaxin Hiyoshi et al. (2005) CB and organic extracts of DEP enhance ovalbuminspecific IgE and IgG1 Heo, Saxon, and Hankinson (2001) Organic extracts of DEP increase neutrophil number in response to LPS but did NOT effect LPS induced cytokine secretion Yanagisawa et al. (2003) PAH enhance IgE production in response to allergen Kanoh et al. (1996) In vitro studies Epithelial cells Organic extracts of DEP increase histamine receptor in nasal epithelial cells as well as histamine-induced IL-8 and GM-CSF release Terada et al. (1999) Organic extracts of DEP increase GM-CSF Boland et al. (1999) DEP but not CB stimulate amphiregulin secretion Blanchet et al. (2004) Organic extracts of DEP increase IL-8 and HO-1 Li et al. (2002) Pyrene increase IL-8 but NOT eotaxin expression in A549 cells Bommel et al. (2003) B(a)P and organic extracts of DEP increase IL-8, GM-CSF and RANTES Kawasaki et al. (2001) Alveolar macrophages Organic extracts of DEP and PM increase IL-8, TNF and COX2 Vogel et al. (2005) Organic extracts of DEP increase IL-8 Li et al. (2002) Organic extracts of DEP did NOT alter costimulatory molecules (B7) and MHC class II (CDIa) expression and antigen presentation Koike and Kobayashi (2005) Organic extracts of DEP decrease PGE2 production by blocking COX-2 enzyme activity Rudra-Ganguly et al. (2002) Organic extracts of DEP reduce production of IL-1and TNF-a in response to inflammatory agents Siegel et al. (2004) Organic extracts of DEP increase IL-1 but not TNF-a Yang et al. (1997) Peripheral blood mononuclear cells (PBMC) Organic extracts of DEP and PAH in presence of LPS increase or decrease IL-10 production depending on the order of exposure Pacheco et al. (2001) Organic extracts of DEP decrease MCP-1 but increase IL-8, RANTES and chemotactic activity for neutrophils and eosinophils Fahy et al. (1999) Organic extracts of DEP decrease IP10 and increase MDC production induced by allergen Fahy et al. (2002) Organic extracts of DEP increase IL-8, RANRES and TNFa in PBMC of allergic persons Fahy et al. (2000) MonoDC Organic extracts of DEP increase the expression of costimulatory molecules (B7) and MHC class II (CDIa) expression and enhance allergen presentation Koike and Kobayashi (2005) PAH during monoDC differentiation decrease expression of CD1a, B7.1 and CD40 as well as DC function Laupeze et al. (2002) Lymph node cells B(a)P induce IL-4 and IL-6 production Fujimakietal. (1997) Tlymphocyte Pyrene increases IL-4 production Bommel et al. (2000) (continued) Particle Toxicology218 © 2007 by Taylor & Francis Group, LLC Table 11.1 (Continued) BlymphocyteOrganic extracts of DEP increase IgE production Tsien et al. (1997) Organic extracts of DEP increase IgE production only in the presence of IL-4 and CD40Ab Takenaka et al. (1995) Basophils Organic extracts of DEP increase IL-4 and histamine release in cells from allergic and non-allergicsubjects Devouassoux et al. (2002) PAH increase IL-4 and histamine release only in presence of IgE Kepley et al. (2003) Mast cell Organic extracts of DEP increase histamine release in the presence of IgE Diaz-Sanchez et al. (2000) Eosinophils Organic extracts of DEP increase degranulation and adhesion to epithelial cells Terada et al. (1997) BP IgE Histamine tryptase Lipid mediators Cytokines Cytokines (IL-1, IL-4,IL-5, IL-6, IL-10, GM-CSF, TNFα ) Chemokines (IL-8, MCP, Eotaxin, RANTES) Eo MC Epithelium NP MBP, ECP, EPO Lipid mediators Cytokines Chronicasthma Epithelial damage bronchial remodeling chronic inflammation bronchial hyperresponsiveness smooth muscle contraction Acute asthma Mucus secretion vasodilatation and vasopermeation bronchial hyperresponsiveness smooth muscle contraction APC Chemotaxis and transmigration of Leucocytes Adhesion molecules endothelium +Ag PAH Adhesion molecules +Ag Histamine receptor AM MPO Proteinases Lipid mediators CD1a B7 Th2 B IL-5 GM-CSF IL-4 IL-6 FIGURE 11.4 Scheme of the inflammatory response induced by PAH. PAH stimulate alveolar macrophages (AM) and epithelial cells to release cytokines and chemokines, inducing the recruitment of peripheral blood leukocytes on which PAH have also direct effects. The cytokines and activation of antigen presenting cells (APC: dendritic cells or macrophages/monocytes) stimulate the differentiation of Tlymphocytes into aTh2 phenotype that is able to induce, in combination with cytokines, the activation and isotype switching of B lymphocytes (B), resulting in IgE production. IgE could induce the release of mediators by mast cells (MC) and basophils (BP) leading to symptoms of acute asthma. Furthermore, the infiltration of eosinophils (Eo) and their prolongedsurvival and activation by cytokines and IgE conducestothe releaseofmediators involved in the development of chronic asthma.Neutrophil(NP) degranulation may lead to bothacute and chronic asthma. Particle-Associated Organics and Proinflammatory Signaling 219 © 2007 by Taylor & Francis Group, LLC couldlead to symptoms of asthma,which have been showntobeaggravated after an increase in PM 10 levels (von Klot et al. 2002). This cytokine and chemokine expressionisassociated with the activation of upstream signaling cascades among which mitogen activated protein kinases (MAPKs) pathways have been shown to be activated by particles. DEP and their organic extractsincrease the ERK 1/2 phosphorylation correlated to the GM-CSF releaseby16HBE cellline as well as that of p38 (Bonvallot et al. 2001). p38 activation has alsobeen implicatedinthe IL-8 mRNA expression induced by DEP and their benzene organic extracts in BEAS-2Bcellline (Kawasaki et al. 2001)and in the release of IL-8 and RANTES induced by DEP extracts in peripheral blood mononuclear cells from allergic patients (Fahy et al. 2000). Finally, JNK phosphorylation was observed in both HBE cells and macrophages exposedtoDEP extracts (Lietal. 2002). Amore global overview of signaling pathwaysactivation was obtainedcombining proteomic and phosphoproteins detection in HBE cells and macrophages exposedtocrude or fractionated DEP extracts (Wang et al. 2005). Thep38 MAPK, JNK, and ERK cascades are activated mainlybyaquinone-containingpolar fraction and to alesser extend by PAH-containingaromatic fraction. Theexpression of manyinflammatory mediatorsisregulated by transcription factorsamong which the redox sensitive transcription factorsNF-k Band AP-1. Whereas many studies have shown the activation of thesetranscription factorsinparticlestreated-cells, few of them address the roleof organic compounds. In HBE cells, DEP and their extracts induced NF-k B(Bonvallot et al. 2001; Kawasaki et al. 2001), but not AP-1activation (Bonvallot et al. 2000). Quinones Quinones DEP/PM Carbonaceous core ROS Receptor Signaling pathways activation ROS CYP CYP Phase Ienzymes (CYP 1A1) Phase II enzymes (GST, NQO-1) antioxidant enzymes (HO-1) Cytokines: GM-CSF, IL-6 chemokines, IL-8, RANTES adhesion molecules (ICAM) PAH AhR XRE ARE NRE TRE PAH PAH-0- quinones NF-κ B AP-1 PAH FIGURE 11.5 Scheme of the metabolic pathways activated by particles and the involvement of their organic component. DEP, diesel exhaust particles; PAH, polyaromatic hydrocarbons; ROS, reactive oxygen species; AhR, aryl hydrocarbon receptor; CYP, cytochrome P450; XRE, xenobiotic responsive element; ARE, anti- oxidant responsive element; NRE, NF-kB responsive element; TRE, TPA responsive element. Particle Toxicology220 © 2007 by Taylor & Francis Group, LLC [...]... diesel exhaust particles, Environ Res., 79, 114 –121, 1998 Pacheco, K A., Tarkowski, M., Sterritt, C., Negri, J., Rosenwasser, L J., and Borish, L., The influence of diesel exhaust particles on mononuclear phagocytic cell-derived cytokines: IL-10, TGF-beta and IL-1 beta, Clin Exp Immunol., 126, 374–383, 2001 Penn, A., Murphy, G., Barker, S., Henk, W., and Penn, L., Combustion-derived ultrafine particles transport... dosimetry of an inhaled particle- borne carcinogen, Carcinogenesis, 22, 741–749, 2001 Gerde, P., Muggenburg, B A., Lundborg, M., Tesfaigzi, Y., and Dahl, A R., Respiratory epithelial penetration and clearance of particle- borne benzo[a]pyrene, Res Rep Health Eff Inst., 5–25, 2001b (discussion 27–32) Gilliland, F D., Li, Y F., Saxon, A., and Diaz-Sanchez, D., Effect of glutathione-S-transferase M1 and P1... GST: Glutathione S-transferase HO-1: Heme oxygenase HBE: Human bronchial epithelial cells Ig: Immunoglobulin IL: Interleukin MAPK: Mitogen activated protein kinase NQO1: NADP(P)H: quinone oxido-reductase Nrf2: NF-E2-related factor-2 NO: Nitric oxide PM2.5: Particulate matter PAH: Polyaromatic hydrocarbons ROS: Reactive oxygen species SOF: Soluble organic fraction REFERENCES Baeza-Squiban, A., Baulig,... particles in ambient air from urban and industrial areas, Sci Total Environ., 348, 199–210, 2005 Riedl, M and Diaz-Sanchez, D., Biology of diesel exhaust effects on respiratory function, J Allergy Clin Immunol., 115 , 221–228, 2005 (quiz 229) Rudra-Ganguly, N., Reddy, S T., Korge, P., and Herschman, H R., Diesel exhaust particle extracts and associated polycyclic aromatic hydrocarbons inhibit Cox-2-dependent... 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Bonvallot, V., Fournier, T., Baeza-Squiban, A., Aubier, M., and Marano, F., Mechanisms of GM-CSF increase by diesel exhaust particles in human airway epithelial cells, Am J Physiol Lung Cell Mol Physiol., 278, L25–L32, 2000 Bolton, J L., Trush, M A., Penning, T M., Dryhurst, G., and Monks, T J., Role of quinones in toxicology, Chem Res Toxicol., 13, 135–160, 2000 Bommel, H., Li-Weber, M., Serfling, E., and . enzymes (GST, NQO-1) antioxidant enzymes (HO-1) Cytokines: GM-CSF, IL-6 chemokines, IL-8, RANTES adhesion molecules (ICAM) PAH AhR XRE ARE NRE TRE PAH PAH- 0- quinones NF-κ B AP-1 PAH FIGURE 11. 5 Scheme. mediators 100 80 60 40 20 pg of GM-CSF /mL pg of GM-CSF /mL 0 C (a) (b) DEP OE-DEP Extracted DEP Carbon black CDEP -cata OE-DEP -cata DEP +cata OE-DEP +cata 100 120 140 80 60 40 20 0 FIGURE 11. 3 GM-CSF release by. Dide ` rot CONTENTS 11. 1Introduction 211 11.2What Is the Role of These Organic Compounds in the Effects of PM? 211 11.2.1 The Particles OrganicFraction 212 11. 2.2 Bioavailability of Organic Compounds 213 11. 2.3