Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
Cancer cells display alterations in many cellular processes. One core hallmark of cancer is the Warburg effect which is a glycolytic reprogramming that allows cells to survive and proliferate. Although the contributions of environmental contaminants to cancer development are widely accepted, the underlying mechanisms have to be clarified. Benzo[a]pyrene (B[a]P), the prototype of polycyclic aromatic hydrocarbons, exhibits genotoxic and carcinogenic effects, and it is a human carcinogen according to the International Agency for Research on Cancer. In addition to triggering apoptotic signals, B[a]P may induce survival signals, both of which are likely to be involved in cancer promotion. We previously suggested that B[a]P-induced mitochondrial dysfunctions, especially membrane hyperpolarization, might trigger cell survival signaling in rat hepatic epithelial F258 cells. Here, we further characterized these dysfunctions by focusing on energy metabolism. We found that B[a]P promoted a metabolic reprogramming. Cell respiration decreased and lactate production increased. These changes were associated with alterations in the tricarboxylic acid cycle which likely involve a dysfunction of the mitochondrial complex II. The glycolytic shift relied on activation of the Na+/H+ exchanger 1 (NHE1) and appeared to be a key feature in B[a]P-induced cell survival related to changes in cell phenotype (epithelial-to-mesenchymal transition and cell migration).
ISSN: 2045-2322

Droits : http://creativecommons.org/licenses/by/
hal-01359569
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01359569
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01359569/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01359569/file/The%20environmental%20carcinogen-CCBY%20%281%29.pdf
DOI : 10.1038/srep30776

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
Meconium is the earliest stool of newborns, and is a complex matrix that reflects the degree of exposure of the fetus to xenobiotics. To investigate fetal exposure to volatile organic compounds, an analytical method was developed to identify and quantify BTEX (benzene, toluene, ethylbenzene, and o,m,p-xylene) and two chlorinated solvents (trichloroethylene and tetrachloroethylene) in meconium. Headspace-solid-phase microextraction coupled with gas chromatography-mass spectrometry was selected because it is simple, sensitive, can be automated, and requires no extensive sample preparation. Several extraction variables were optimized (fiber type, incubation time, temperature of fiber, and use of salt). Because meconium is a complex matrix, quantification by SPME was considered carefully because of potential interference, for example competitive adsorption. Calibration in water was compared with calibration in meconium using external and internal methods (with isotope-labeled compounds). In meconium, limits of quantification were determined to be in the range 0.064-0.096 ng g(-1) for the investigated compounds. All target compounds were determined in "real-case" meconium samples.
ISSN: 1618-2642

hal-01064967
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01064967
DOI : 10.1007/s00216-014-7836-2
PUBMED : 24838489

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
Exposure to environmental polycyclic aromatic hydrocarbons (PAHs), such as benzo(a) pyrene (B(a) P), has been linked to several health-threatening risks. PAHs were also shown to hinder adrenergic receptor (ADR) responses. As we previously demonstrated that Ba) P can directly interact with the beta 2ADR, we investigated here whether B(a) P could decrease beta 2ADR responsiveness by triggering receptor desensitization phenomena. We firstly showed that exposure to B(a) P reduced beta 2ADRmediated epinephrine-induced induction of NR4A gene mRNAs and of intracellular cAMP. Analysis of beta 2ADR protein expression demonstrated that B(a) P rapidly decreased membrane expression of beta 2ADR with a subsequent degradation of receptor protein. B(a) P exposure concomitantly rapidly increased the beta 2ADR mRNA levels. The use of the beta-blockers, propranolol and ICI 118.551, demonstrated the involvement of beta 2ADR itself in this increase. However, sustained exposure to Ba) P induced a diminution of beta 2ADR mRNA steady-state as a result of the acceleration of its degradation. Together, these results show that, beside the well-known activation of the aryl hydrocarbon receptor, PAH deleterious effects may involve the dysfunction of adrenergic responses through, in part, the desensitization of beta 2ADR. This may be taken in consideration when beta 2-agonists/antagonists are administered in patients exposed to important concentrations of PAHs, e.g. in cigarette smokers.
ISSN: 2045-2322

hal-01560151
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01560151
DOI : 10.1038/s41598-017-03646-4
PUBMED : 28607424

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
Most tumors undergo metabolic reprogramming towards glycolysis, the so-called Warburg effect, to support growth and survival. Overexpression of IF1, the physiological inhibitor of the F0F1ATPase, has been related to this phenomenon and appears to be a relevant marker in cancer. Environmental contributions to cancer development are now widely accepted but little is known about the underlying intracellular mechanisms. Among the environmental pollutants humans are commonly exposed to, benzo[a]pyrene (B[a]P), the prototype molecule of polycyclic aromatic hydrocarbons (PAHs), is a well-known human carcinogen. Besides apoptotic signals, B[a]P can also induce survival signals in liver cells, both likely involved in cancer promotion. Our previous works showed that B[a]P elicited a Warburg-like effect, thus favoring cell survival. The present study aimed at further elucidating the molecular mechanisms involved in the B[a]P-induced metabolic reprogramming, by testing the possible involvement of IF1. We presently demonstrate, both in vitro and in vivo, that PAHs, especially B[a]P, strongly increase IF1 expression. Such an increase, which might rely on β2-adrenergic receptor activation, notably participates to the B[a]P-induced glycolytic shift and cell survival in liver cells. By identifying IF1 as a target of PAHs, this study provides new insights about how environmental factors may contribute to related carcinogenesis.
ISSN: 2045-2322

hal-01518808
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01518808
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01518808/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01518808/file/Hardonni%C3%A8re%20et%20al%202017.pdf
DOI : 10.1038/s41598-017-00269-7

Éditeur(s) : HAL CCSD springer Link
Résumé : International audience
Experimental Astronomy

hal-01094521
https://hal.archives-ouvertes.fr/hal-01094521
BIBCODE : 2014ExA...tmp...41R
DOI : 10.1007/s10686-014-9383-4
ARXIV : 1310.0696

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Lung diseases are aggravated by exposure to diesel exhaust particles (DEPs) found in air pollution. Macrophages are thought to play a crucial role in lung immune response to these pollutants, even if the mechanisms involved remain incompletely characterized. In the present study, we demonstrated that classically and alternative human macrophages (MΦ) exhibited increased secretion of PDGF-B in response to DEP extract (DEPe). This occurred via aryl hydrocarbon receptor (AhR)-activation because DEPe-induced PDGF-B overexpression was abrogated after AhR expression knock-down by RNA interference, in both M1 and M2 polarizing MΦ. In addition, TCDD and benzo(a)pyrene, two potent AhR ligands, also significantly increased mRNA expression of PDGF-B in M1 MΦ, whereas some weak ligands of AhR did not. We next evaluated the impact of conditioned media (CM) from MΦ culture exposed to DEPe or of recombinant PDGF-B onto lung fibroblast proliferation. The tyrosine kinase inhibitor, AG1295, prevents phosphorylations of PDGF-Rβ, AKT and ERK1/2 and the proliferation of MRC5 fibroblasts induced by recombinant PDGF-B and by CM from M1 polarizing MΦ, strongly suggesting that the PDGF-BB secreted by DEPe-exposed MΦ is sufficient to activate the PDGF-Rβ pathway of human lung fibroblasts. In conclusion, we demonstrated that human MΦ, whatever their polarization status, secrete PDGF-B in response to DEPe and that PDGF-B is a target gene of AhR. Therefore, induction of PDGF-B by DEP may participate in the deleterious effects towards human health triggered by such environmental urban contaminants.
ISSN: 0041-008X

hal-01146840
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01146840
DOI : 10.1016/j.taap.2015.04.007
PUBMED : 25896968

Extrait de : Sciences et voyages,n°103, p. 41-47, p. 51
Résumé : Article + photos 7 p. + 1 p.
Siècle(s) traité(s) : 20
Droits : Domaine public
Provenance : ORkidé|Fonds privé Pierre Rostan
Permalien : http://www.manioc.org/patrimon/ORK12133
ORK12133

Éditeur(s) : HAL CCSD
Résumé : International audience
Toxicology Letters
Paris, France

hal-01122684
https://hal.archives-ouvertes.fr/hal-01122684
DOI : 10.1016/j.toxlet.2011.05.436

Éditeur(s) : Paris : Laurent d'Houry
Siècle(s) traité(s) : 18
Droits : Domaine public
Provenance : Collectivité territoriale de Martinique. Bibliothèque Schoelcher
Permalien : http://www.manioc.org/patrimon/SCH13253
SCH13253

Éditeur(s) : Toulouse : Imprimerie F. Estellé
Résumé : La première partie reprend l'histoire des jaborandi, plante sudorifique
Siècle(s) traité(s) : 20
Droits : Domaine public
Provenance : Fondation Clément
Permalien : http://www.manioc.org/patrimon/FCL15018
FCL15018

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Nutrition Clinique et Métabolisme
Bordeaux, France

hal-01122530
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01122530
DOI : 10.1016/S0985-0562(13)70319-4

Éditeur(s) : Cluny : Imprimerie J.-M. Demoule
Siècle(s) traité(s) : 19
Droits : Domaine public
Provenance : Collectivité territoriale de Guyane. Bibliothèque Alexandre-Franconie
Permalien : http://www.manioc.org/patrimon/FRA11064
FRA11064

Extrait de : Sciences et voyages, n°287
Résumé : Article et photographies
Siècle(s) traité(s) : 20
Droits : Domaine public
Provenance : ORkidé|Fonds privé Pierre Rostan
Permalien : http://www.manioc.org/patrimon/ORK12131
ORK12131

Éditeur(s) : Paris : Panckouke
Extrait de : Histoire de l'Amérique
Siècle(s) traité(s) : 16
Droits : Domaine public
Provenance : Ville de Pointe-à-Pitre. Réseau des bibliothèques
Permalien : http://www.manioc.org/patrimon/PAP11075
PAP11075

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Semi-Volatile Organic Compounds (SVOCs) are commonly present in dwellings and several are suspected of having effects on male reproductive function mediated by an endocrine disruption mode of action. To improve knowledge of the health impact of these compounds, cumulative toxicity indicators are needed. This work derives Benchmark Doses (BMD) and Relative Potency Factors (RPF) for SVOCs acting on the male reproductive system through the same mode of action. We included SVOCs fulfilling the following conditions: detection frequency (>10%) in French dwellings, availability of data on the mechanism/mode of action for male reproductive toxicity, and availability of comparable dose-response relationships. Of 58 SVOCs selected, 18 induce a decrease in serum testosterone levels. Six have sufficient and comparable data to derive BMDs based on 10 or 50% of the response. The SVOCs inducing the largest decrease in serum testosterone concentration are: for 10%, bisphenol A (BMD10= 7.72E-07 mg/kg bw/d; RPF10= 7033679); for 50%, benzo[a]pyrene (BMD50= 0.030 mg/kg bw/d; RPF50= 1630), and the one inducing the smallest one is benzyl butyl phthalate (RPF10 and RPF50= 0.095). This approach encompasses contaminants from diverse chemical families acting through similar modes of action, and makes possible a cumulative risk assessment in indoor environments. The main limitation remains the lack of comparable toxicological data.
ISSN: 0273-2300

hal-01237085
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01237085
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01237085/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01237085/file/Multiple%20exposures%20to%20indoor%20contaminants_accepted.pdf
DOI : 10.1016/j.yrtph.2015.11.017

Éditeur(s) : Fort-de-France : Imprimerie antillaise
Résumé : Nouvelle série n°4
Siècle(s) traité(s) : 19
Droits : Domaine public
Provenance : Collectivité territoriale de Guyane. Bibliothèque Alexandre-Franconie
Permalien : http://www.manioc.org/patrimon/FRA11183
FRA11183

Éditeur(s) : Paris : Panckouke
Extrait de : Histoire de l'Amérique
Siècle(s) traité(s) : 16
Droits : Domaine public
Provenance : Ville de Pointe-à-Pitre. Réseau des bibliothèques
Permalien : http://www.manioc.org/patrimon/PAP11074
PAP11074

Éditeur(s) : Paris : A. Challamel
Siècle(s) traité(s) : 20
Droits : Domaine public
Provenance : Collectivité territoriale de Guyane. Bibliothèque Alexandre-Franconie
Permalien : http://www.manioc.org/patrimon/FRA11113
FRA11113

Siècle(s) traité(s) : 20
Droits : Domaine public
Provenance : Collectivité territoriale de Guyane. Bibliothèque Alexandre-Franconie
Permalien : http://www.manioc.org/patrimon/FRA11050
FRA11050

Éditeur(s) : Paris : Plon
Siècle(s) traité(s) : 19
Droits : Domaine public
Provenance : Collectivité territoriale de Guyane. Bibliothèque Alexandre-Franconie
Permalien : http://www.manioc.org/patrimon/FRA12343
FRA12343