Biological effects of particles from the paris subway system.
Particulate matter (PM) from atmospheric pollution can easily deposit in the lungs and induce recruitment of inflammatory cells, a source of inflammatory cytokines, oxidants, and matrix metalloproteases (MMPs), which are important players in lung structural homeostasis. In many large cities, the subway system is a potent source of PM emission, but little is known about the biological effects of PM from this source. We performed a comprehensive study to evaluate the biological effects of PM sampled at two sites (RER and Metro) in the Paris subway system. Murine macrophages (RAW 264.7) and C57Bl/6 mice, respectively, were exposed to 0.01-10 microg/cm2 and 5-100 microg/mouse subway PM or reference materials [carbon black (CB), titanium dioxide (TiO2), or diesel exhaust particles (DEPs)]. We analyzed cell viability, production of cellular and lung proinflammatory cytokines [tumor necrosis factor alpha (TNFalpha), macrophage inflammatory protein (MIP-2), KC (the murin analog of interleukin-8), and granulocyte macrophage-colony stimulating factor (GM-CSF)], and mRNA or protein expression of MMP-2, -9, and -12 and heme oxygenase-1 (HO-1). Deferoxamine and polymixin B were used to evaluate the roles of iron and endotoxin, respectively. Noncytotoxic concentrations of subway PM (but not CB, TiO2, or DEPs) induced a time- and dose-dependent increase in TNFalpha and MIP-2 production by RAW 264.7 cells, in a manner involving, at least in part, PM iron content (34% inhibition of TNF production 8 h after stimulation of RAW 264.7 cells with 10 microg/cm2 RER particles pretreated with deferoxamine). Similar increased cytokine production was transiently observed in vivo in mice and was accompanied by an increased neutrophil cellularity of bronchoalveolar lavage (84.83+/-0.98% of polymorphonuclear neutrophils for RER-treated mice after 24 h vs 7.33+/-0.99% for vehicle-treated animals). Subway PM induced an increased expression of MMP-12 and HO-1 both in vitro and in vivo. PM from the Paris subway system has transient biological effects. Further studies are needed to better understand the pathophysiological implications of these findings.
Bachoual
Rafik
R
Inserm, U700 Université Paris 7 Denis Diderot, site Bichat, and Biochimie B, Assistance Publique-Hôpitaux de Paris, Hôpital Bichat, Paris, France.
Boczkowski
Jorge
J
Goven
Delphine
D
Amara
Nadia
N
Tabet
Lyes
L
On
Dinhill
D
Leçon-Malas
Véronique
V
Aubier
Michel
M
Lanone
Sophie
S
D000280:Administration, Inhalation; D000393:Air Pollutants / Q000633:toxicity*; D000818:Animals; D001980:Bronchi / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D001992:Bronchoalveolar Lavage Fluid; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002947:Cities; D017364:Collagenases / Q000235:genetics / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004784:Environmental Monitoring / Q000379:methods; D015870:Gene Expression / Q000187:drug effects; D006419:Heme Oxygenase (Decyclizing) / Q000235:genetics / Q000378:metabolism; D019570:Inhalation Exposure; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009504:Neutrophils / Q000187:drug effects / Q000473:pathology; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D052638:Particulate Matter / Q000633:toxicity*; D011890:Railroads; D019714:Tissue Inhibitor of Metalloproteinases / Q000235:genetics / Q000378:metabolism
D000393:Air Pollutants; D016207:Cytokines; D052638:Particulate Matter; D019714:Tissue Inhibitor of Metalloproteinases; D006419:Heme Oxygenase (Decyclizing); D017364:Collagenases