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Papers by Virginie Tassistro

Research paper thumbnail of Poorly soluble cobalt oxide particles trigger genotoxicity via multiple pathways

Particle and fibre toxicology, 2016

Poorly soluble cobalt (II, III) oxide particles (Co3O4P) are believed to induce in vitro cytotoxi... more Poorly soluble cobalt (II, III) oxide particles (Co3O4P) are believed to induce in vitro cytotoxic effects via a Trojan-horse mechanism. Once internalized into lysosomal and acidic intracellular compartments, Co3O4P slowly release a low amount of cobalt ions (Co(2+)) that impair the viability of in vitro cultures. In this study, we focused on the genotoxic potential of Co3O4P by performing a comprehensive investigation of the DNA damage exerted in BEAS-2B human bronchial epithelial cells. Our results demonstrate that poorly soluble Co3O4P enhanced the formation of micronuclei in binucleated cells. Moreover, by comet assay we showed that Co3O4P induced primary and oxidative DNA damage, and by scoring the formation of γ-H2Ax foci, we demonstrated that Co3O4P also generated double DNA strand breaks. By comparing the effects exerted by poorly soluble Co3O4P with those obtained in the presence of soluble cobalt chloride (CoCl2), we demonstrated that the genotoxic effects of Co3O4P are no...

Research paper thumbnail of Expression of adrenomedullin in human epicardial adipose tissue: role of coronary status

AJP: Endocrinology and Metabolism, 2007

Epicardial white adipose tissue (eWAT) is in close contact with coronary vessels and therefore co... more Epicardial white adipose tissue (eWAT) is in close contact with coronary vessels and therefore could alter coronary homeostasis. Adrenomedullin (AM) is a potent vasodilatator and antioxidative peptide which has been shown to play a cytoprotective role in experimental models of acute myocardial infarction. We studied, using immunohistochemistry and qRT-PCR, the expression of AM and its receptors calcitonin receptor-like receptor (CRLR), and receptor activity-modifying protein (RAMP)2 and -3 in paired biopsies of subcutaneous WAT (sWAT) and eWAT obtained from patients with coronary artery disease (CAD) or without CAD (NCAD). In eWAT obtained from NCAD or CAD patients, immunoreactivity for AM, CRLR, and RAMP2 and -3 was detected in blood vessel walls and isolated stromal cells close to adipocytes. Some of the AM positive stromal cells colocalized CD68 immunoreactivity. eWAT from CAD patients showed increased AM immunoreactivity and AM gene expression. CRLR mRNA levels were comparable in sWAT of both groups and decreased by 40-50% in eWAT, irrespectively of the coronary status. RAMP2 mRNA concentrations did not change while RAMP3 mRNA levels increased in sWAT from CAD patients. There was a positive linear relationship between eWAT 11beta-hydroxysteroid dehydrogenase type 1 mRNA (11beta-HSD-1, the enzyme that converts inactive to active glucocorticoids) and AM mRNA. In conclusion, we demonstrate that AM and its receptors are expressed in eWAT. Our data suggest that eWAT AM, which could originate from macrophages, is related to 11beta-HSD-1 expression. AM synthesis, which is increased in eWAT during chronic CAD in humans, can play a cardioprotective role.

Research paper thumbnail of Immediate Postnatal Overfeeding in Rats Programs Aortic Wall Structure Alterations and Metalloproteinases Dysregulation in Adulthood

American journal of hypertension, Jan 6, 2015

Alterations in the nutritional perinatal environment, such as intrauterine growth retardation wit... more Alterations in the nutritional perinatal environment, such as intrauterine growth retardation with subsequent postnatal catch-up growth, program cardiovascular disease in adulthood, possibly through alterations in matrix metalloproteinase (MMP)-2 and -9. However, experimental evidences demonstrating that changes in the nutritional perinatal environment can program MMP-2 and -9 with subsequent alterations of vessel wall are lacking. The current study evaluated whether immediate postnatal overfeeding is able to alter vascular morphological indexes and circulating and/or vascular MMP2-2 and -9 status. Aortic morphology (wall thickness and percentage of incomplete elastin lamellae) and circulating and aortic MMP-2 and -9 activity (measured by gelatin zymography) and aortic MMP-2 and -9 mRNA (measured by reverse transcription polymerase chain reaction (RT-PCR)) were studied in adult male rats overfed (OF) or normofed (NF) during the immediate postnatal period. Postnatal overfeeding induc...

Research paper thumbnail of Chronology of meiosis & synaptonemal complex abnormalities in normal & abnormal spermatogenesis

The Indian Journal of Medical Research

The study was taken up to define criteria of normality for meiosis by assessing the frequency of ... more The study was taken up to define criteria of normality for meiosis by assessing the frequency of meiotic prophase cell types, the frequency of pachytene substage in normal and abnormal spermatogenesis and to determine what synaptonemal complex.

Research paper thumbnail of Chronology of meiosis & synaptonemal complex abnormalities in normal & abnormal spermatogenesis

The Indian journal of medical research, 2009

The study was taken up to define criteria of normality for meiosis by assessing the frequency of ... more The study was taken up to define criteria of normality for meiosis by assessing the frequency of meiotic prophase cell types, the frequency of pachytene substage in normal and abnormal spermatogenesis and to determine what synaptonemal complex. A quantitative and qualitative analysis of the first meiotic prophase was performed in 10 patients presenting with non-obstructive infertility and 10 controls, using dual colour immunocytochemistry with SCP3 and BRCA1 which visualise axial elements and synaptonemal complexes (SC). The respective frequencies of the leptotene, zygotene and pachytene stages as well as the frequencies of the four substages of pachytene were evaluated. The frequencies of the main types of meiotic abnormalities at pachytene were also assessed. The frequencies of leptotene and zygotene stages were significantly higher in patients (7.95 and 9.75%) than in controls (2.30 and 1.45%), whereas the frequency of pachytene was significantly higher in controls than in patien...

Research paper thumbnail of Expression and nutritional regulation of the (pro)renin receptor in rat visceral adipose tissue

Journal of endocrinological investigation, 2011

Early life nutritional environment plays an important role in the development of visceral adipose... more Early life nutritional environment plays an important role in the development of visceral adipose tissue and interacts with nutritional regulations in adulthood, leading to metabolic dysregulations. We hypothesized that the renin-angiotensin system may play a role in the programming-induced development of visceral adipose tissue. We studied, using a model of programming of overweight and glucose intolerance, obtained by post-natal overfeeding with consecutive highfat diet, the status of plasma renin activity and mesenteric adipose renin-angiotensin system, including the recently identified (pro)renin receptor, in adult rats. Post-natal overfeeding or high-fat feeding lead to overweight with increased visceral fat mass and adipocytes surface. When both paradigms were associated, adipocytes surface showed a disproportionate increase. A strong immunoreactivity for (pro)renin receptor was found in stromal cells. Plasma renin activity increased in programmed animals whereas (pro)renin re...

Research paper thumbnail of Chromosomes sexuels et méiose

Gynécologie Obstétrique & Fertilité, 2009

Le comportement des chromosomes sexuels diffère fondamentalement au cours des méioses spermatocyt... more Le comportement des chromosomes sexuels diffère fondamentalement au cours des méioses spermatocytaire et ovocytaire. Dans l'ovocyte, les chromosomes X s'apparient sur toute leur longueur formant un bivalent XX qui ne se distingue pas des bivalents autosomiques, par sa morphologie et son comportement. Chez l'homme, les différences morphologiques et génétiques qui existent entre les chromosomes X et Y vont limiter leur appariement et interdire toute recombinaison génétique excepté dans la région d'homologie PAR1. Au cours du stade pachytène de la prophase I, les chromosomes X et Y se condensent progressivement pour former le corps XY transcriptionnellement inactif à la périphérie du noyau. La condensation du bivalent XY au cours du stade pachytène nous a permis de définir quatre sous-stades pachytène et de localiser le point de contrôle du pachytène entre les sous-stades 2 et 3. Nous avons aussi montré que l'index du pachytène (PI = P1 + P2/P1 + P2 + P3 + P4) était toujours inférieur à 0,50 dans les méioses normales. Alors que le corps XY se décondense au stade diplotène de la prophase I, l'inactivation transcriptionnelle des chromosomes sexuels ou meiotic sex chromosome inactivation (MSCI) persiste jusqu'à la fin de la spermatogenèse. Ce mécanisme d'inactivation fait intervenir des protéines dont un petit nombre a été maintenant identifié, parmi elles, les protéines HP1b et HP1g, impliquées dans l'hétérochromatinisation facultative des chromosomes sexuels. Cependant, l'initiation de la MSCI fait intervenir la phosphorylation de la protéine H2AX par la kinase ATR, elle-même recrutée par BRCA1. Une connaissance plus approfondie des phénomènes d'inactivation des chromosomes sexuels au cours de la méiose mâle permettra de mieux définir les étiologies d'un certain nombre d'infertilités masculines. # 2009 Elsevier Masson SAS. Tous droits réservés.

Research paper thumbnail of A new approach for the oocyte genotoxicity assay: adaptation of comet assay on mouse cumulus-oocyte complexes

Laboratory Animals, 2014

Conventional genotoxicity tests are technically difficult to apply to oocytes, and results obtain... more Conventional genotoxicity tests are technically difficult to apply to oocytes, and results obtained on somatic cells cannot be extrapolated to gametes. We have previously described a comet assay (original-CA) on denuded mouse oocytes, but, in vivo, oocytes are not isolated from their surrounding follicular cells. Our objective was to develop a comet assay on cumulus-oocyte complexes (COC-CA) for a more physiological approach to study the genotoxicity of environmental factors on oocytes. For COC-CA, whole COC were exposed directly to exogenous agents after ovulation and removal from oviducts. Three conditions were studied: a negative control group, and two positive control groups, one of which was exposed to hydrogen peroxide (H2O2) and the other group was incubated with cerium dioxide nanoparticles (CeO2 NPs). With both tests, DNA damage was significant in the presence of both H2O2 and CeO2 NPs compared with the negative control. COC-CA offers an interesting tool for assaying the genotoxicity of environmental agents towards germinal cells. Furthermore, COC-CA is less time-consuming and simplifies the protocol of the original-CA, because COC-CA is easier to perform without the washing-out procedure.

Research paper thumbnail of DNA damage and oxidative stress induced by CeO2 nanoparticles in human dermal fibroblasts: Evidence of a clastogenic effect as a mechanism of genotoxicity

Nanotoxicology, Jan 17, 2014

The broad range of applications of cerium oxide (CeO2) nanoparticles (nano-CeO2) has attracted in... more The broad range of applications of cerium oxide (CeO2) nanoparticles (nano-CeO2) has attracted industrial interest, resulting in greater exposures to humans and environmental systems in the coming years. Their health effects and potential biological impacts need to be determined for risk assessment. The aims of this study were to gain insights into the molecular mechanisms underlying the genotoxic effects of nano-CeO2 in relation with their physicochemical properties. Primary human dermal fibroblasts were exposed to environmentally relevant doses of nano-CeO2 (mean diameter, 7 nm; dose range, 6 × 10(-5)-6 × 10(-3) g/l corresponding to a concentration range of 0.22-22 µM) and DNA damages at the chromosome level were evaluated by genetic toxicology tests and compared to that induced in cells exposed to micro-CeO2 particles (mean diameter, 320 nm) under the same conditions. For this purpose, cytokinesis-blocked micronucleus assay in association with immunofluorescence staining of centr...

Research paper thumbnail of Ultrastructural interactions and genotoxicity assay of cerium dioxide nanoparticles on mouse oocytes

International journal of molecular sciences, 2013

Cerium dioxide nanoparticles (C(e)O₂ ENPs) are on the priority list of nanomaterials requiring ev... more Cerium dioxide nanoparticles (C(e)O₂ ENPs) are on the priority list of nanomaterials requiring evaluation. We performed in vitro assays on mature mouse oocytes incubated with C(e)O₂ ENPs to study (1) physicochemical biotransformation of ENPs in culture medium; (2) ultrastructural interactions with follicular cells and oocytes using Transmission Electron Microscopy (TEM); (3) genotoxicity of C(e)O₂ ENPs on follicular cells and oocytes using a comet assay. DNA damage was quantified as Olive Tail Moment. We show that ENPs aggregated, but their crystal structure remained stable in culture medium. TEM showed endocytosis of C(e)O₂ ENP aggregates in follicular cells. In oocytes, C(e)O₂ ENP aggregates were only observed around the zona pellucida (ZP). The comet assay revealed significant DNA damage in follicular cells. In oocytes, the comet assay showed a dose-related increase in DNA damage and a significant increase only at the highest concentrations. DNA damage decreased significantly bot...

Research paper thumbnail of Detection of 1,N6-ethenoadenosine exocyclic adducts on human lymphocytes by immunocytochemistry

Toxicology Letters, 2011

Acrylonitrile (AN) is a probable human carcinogen and is also a widely used monomer in industries... more Acrylonitrile (AN) is a probable human carcinogen and is also a widely used monomer in industries. AN can be detoxified by glutathione S-transferase (GST) to form glutathione (GSH) conjugates in vivo. If not, it can be metabolically activated by cytochrome P450 2E1 (CYP2E1) to form 2cyanoethylene oxide (CEO), which can also be detoxified by GST to generate GSH conjugates. The conjugates can be further metabolized to N-acetyl-S-(2-cyanoethyl)cysteine (CEMA), N-acetyl-S-(2-hydroxyethyl)cysteine (HEMA), and N-acetyl-S-(1cayno-2-hydroxyethyl)cysteine (CHEMA), respectively. The objective of the study was to quantify the major mercapturic acids (MAs) of AN in urine of AN-exposed workers to validate MAs as biological markers for AN exposures and to study inter-and intra-species differences in AN metabolism. Eighty exposed and 23 non-exposed workers were recruited from three AN-used factories in Taiwan. Personal air samples and urine samples were collected. AN was analyzed by gas chromatographic coupled with flame ionization detector (GC-FID). Urinary MAs were quantified by an ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Data analysis reveals that AN-exposed workers excreted significantly higher MAs levels than non-exposed workers. Linear regression analysis showed significant correlations between AN exposures and MAs concentrations. For those with detectable AN exposures, the ratios of CHEMA/CEMA or (HEMA + CHEMA)/CEMA at post-shift was significantly greater than those at pre-shift, and suggested potential induction of AN metabolism in workers exposed to low concentrations of AN.

Research paper thumbnail of Smoking and benzo(a)pyrene-diol-epoxide DNA adducts in spermatozoa: In smokers, swim-up procedure selects spermatozoa with decreased DNA damage

Toxicology Letters, 2011

Abstracts / Toxicology Letters 205S (2011) S180-S300 S253 10-11 Sprague-Dawley rats were administ... more Abstracts / Toxicology Letters 205S (2011) S180-S300 S253 10-11 Sprague-Dawley rats were administered DMEP (5 ml/kg) on days 6-20 of gestation (GD) at doses of 0 (vehicle: olive oil), 25, 50, 100, 150, or 200 mg/kg/day. Dams were euthanized on GD 21. Live fetuses were weighed and submitted to external examination and internal evaluation of the gonads. No test dams died. Maternal body weight and weight gain were significantly reduced by the end of gestation (GD 18-21) at 150 mg/kg, and during the second half of gestation (after GD 12) at 200 mg/kg/day. However, the corrected body weight gains were comparable across groups and these decreases were attributed to the significantly lower gravid uterine weights. The incidence of post-implantation loss was significantly increased at 150 mg/kg, and reached 87% at 200 mg/kg. There was a pronounced and dose-related decrease in fetal body weight, which was significantly different from control at 100 mg/kg/day and higher doses. Fetal external malformations were observed at 100 mg/kg/day and above. They mainly consisted of anal atresia with absent tail, and edema. No effect was seen on fetal testicular descent. Thus, DMEP was embryotoxic and teratogenic at doses which did not produce overt maternal toxicity.

Research paper thumbnail of In vivo exposure to benzo(a)pyrene induces significant DNA damage in mouse oocytes and cumulus cells

Human Reproduction, 2014

study question: Does in vivo exposure to benzo(a)pyrene (BaP) induce DNA damage in oocytes and cu... more study question: Does in vivo exposure to benzo(a)pyrene (BaP) induce DNA damage in oocytes and cumulus cells (CCs) in mice? summaryanswer: Significant increases in DNA strand breaks in oocytes and CCs and in BaP-induced DNA adducts in CCs were detected in exposed mice compared with controls.

Research paper thumbnail of In smokers, swim-up and discontinuous gradient centrifugation recover spermatozoa with equally lower amounts of DNA damage than spermatozoa obtained from neat semen

Fertility and Sterility, 2011

In smokers, swim-up and discontinuous gradient centrifugation recover spermatozoa with equally lo... more In smokers, swim-up and discontinuous gradient centrifugation recover spermatozoa with equally lower amounts of DNA damage than spermatozoa obtained from neat semen

Research paper thumbnail of Tobacco consumption and benzo(a)pyrene-diol-epoxide–DNA adducts in spermatozoa: in smokers, swim-up procedure selects spermatozoa with decreased DNA damage

Fertility and Sterility, 2011

Objective: To analyze the distribution of benzo(a)pyrene-diol-epoxide (BPDE)-DNA adducts in sperm... more Objective: To analyze the distribution of benzo(a)pyrene-diol-epoxide (BPDE)-DNA adducts in spermatozoa selected and nonselected by a swim-up procedure with relation to smoking habits. Design: Comparative study. Setting: Public university and public university hospital. Patient(s): Seventy-nine men (37 smokers and 42 nonsmokers) who visited an infertility clinic for diagnostic. Intervention(s): Tobacco and environmental exposure assessment, semen sample analysis, swim-up procedure, BPDE-DNA adduct immunolabeling. Main Outcome Measure(s): BPDE-DNA adduct quantification in selected (SEL-SPZ) and nonselected (NONSEL-SPZ) spermatozoa. Data were normalized by using a normalized fluorescence value (NFV).

Research paper thumbnail of P43 La suralimentation post-natale précoce programme un remodelage de la paroi aortique chez le rat adulte

Diabetes & Metabolism, 2010

Research paper thumbnail of Postnatal Programming of Glucocorticoid Metabolism in Rats Modulates High-Fat Diet-Induced Regulation of Visceral Adipose Tissue Glucocorticoid Exposure and Sensitivity and Adiponectin and Proinflammatory Adipokines Gene Expression in Adulthood

Diabetes, 2008

OBJECTIVE-Alterations of the perinatal environment, which lead to increased prevalence of the met... more OBJECTIVE-Alterations of the perinatal environment, which lead to increased prevalence of the metabolic syndrome in adulthood, program an upregulation of systemic and/or adipose tissue glucocorticoid metabolism (11␤-hydroxysteroid dehydrogenase type 1 [11␤-HSD-1]-induced corticosterone reactivation). We hypothesized that postnatal programming could modulate high-fat diet-induced adipose tissue dysregulation in adulthood. RESEARCH DESIGN AND METHODS-We compared the effects of chronic (since weaning) high-or low-fat diet in postnatally normofed (control) or overfed (programmed) rats. RESULTS-Postnatal programming accentuated high-fat dietinduced overweight, insulin resistance, glucose intolerance, and decrease in circulating and epididymal adipose tissue adiponectin. Neither manipulation altered liver function. Postnatal programming or high-fat diet increased systemic corticosterone production, which was not further modified when both manipulations were associated. Postnatal programming suppressed high-fat diet-induced decrease in mesenteric adipose tissue (MAT) glucocorticoid sensitivity and triggered high-fat dietinduced increase in MAT glucocorticoid exposure, subsequent to enhanced MAT 11␤-HSD-1 gene expression. MAT tumor necrosis factor (TNF)-␣, TNF-receptor 1, interleukin (IL)-6, resistin, and plasminogen activator inhibitor-1 mRNAs were not changed by high-fat feeding in control rats and showed a large increase in programmed animals, with this effect further enhanced by highfat diet for TNF-␣ and IL-6. CONCLUSIONS-Our data show for the first time that postnatal manipulation programs high-fat diet-induced upregulation of MAT glucocorticoid exposure, sensitivity, and inflammatory status and therefore reveal the pivotal role of the environment during the perinatal period on the development of diet-induced adipose tissue dysregulation in adulthood. They also urge the need for clinical trials with specific 11␤-HSD-1 inhibitors. Diabetes

Research paper thumbnail of Surveillance biologique des expositions aux hydrocarbures aromatiques polycycliques : de la biométrologie à la biogénotoxicologie et de la génotoxicité somatique à la génotoxicité germinale

Archives des Maladies Professionnelles et de l'Environnement, 2012

Research paper thumbnail of Expression of adrenomedullin in human epicardial adipose tissue: role of coronary status

AJP: Endocrinology and Metabolism, 2007

Epicardial white adipose tissue (eWAT) is in close contact with coronary vessels and therefore co... more Epicardial white adipose tissue (eWAT) is in close contact with coronary vessels and therefore could alter coronary homeostasis. Adrenomedullin (AM) is a potent vasodilatator and antioxidative peptide which has been shown to play a cytoprotective role in experimental models of acute myocardial infarction. We studied, using immunohistochemistry and qRT-PCR, the expression of AM and its receptors calcitonin receptor-like receptor (CRLR), and receptor activity-modifying protein (RAMP)2 and -3 in paired biopsies of subcutaneous WAT (sWAT) and eWAT obtained from patients with coronary artery disease (CAD) or without CAD (NCAD). In eWAT obtained from NCAD or CAD patients, immunoreactivity for AM, CRLR, and RAMP2 and -3 was detected in blood vessel walls and isolated stromal cells close to adipocytes. Some of the AM positive stromal cells colocalized CD68 immunoreactivity. eWAT from CAD patients showed increased AM immunoreactivity and AM gene expression. CRLR mRNA levels were comparable in sWAT of both groups and decreased by 40-50% in eWAT, irrespectively of the coronary status. RAMP2 mRNA concentrations did not change while RAMP3 mRNA levels increased in sWAT from CAD patients. There was a positive linear relationship between eWAT 11beta-hydroxysteroid dehydrogenase type 1 mRNA (11beta-HSD-1, the enzyme that converts inactive to active glucocorticoids) and AM mRNA. In conclusion, we demonstrate that AM and its receptors are expressed in eWAT. Our data suggest that eWAT AM, which could originate from macrophages, is related to 11beta-HSD-1 expression. AM synthesis, which is increased in eWAT during chronic CAD in humans, can play a cardioprotective role.

Research paper thumbnail of Cerium dioxide nanoparticles affect in vitro fertilization in mice

Nanotoxicology, 2015

Due to their catalytic and oxidative properties, cerium dioxide nanoparticles (CeO 2 NPs) are wid... more Due to their catalytic and oxidative properties, cerium dioxide nanoparticles (CeO 2 NPs) are widely used as diesel additive or as promising therapy in cancerology; yet, scarce data are available on their toxicity, and none on their reproductive toxicity. We showed a significant decrease of fertilization rate, assessed on 1272 oocytes, during in vitro fertilization (IVF) carried out in culture medium containing CeO 2 NP at very low concentration (0.01 mg.l À1 ). We also showed significant DNA damage induced in vitro by CeO 2 NP on mouse spermatozoa and oocytes at 0.01 mg.l À1 using Comet assay. Transmission Electron Microscopy did not detect any nanoparticles in the IVF samples at 0.01 mg.l À1 , but showed, at high concentration (100 mg.l À1 ), their endocytosis by the cumulus cells surrounding oocytes and their accumulation along spermatozoa plasma membranes and oocytes zona pellucida. We did not observe any nanoparticles in the cytoplasm of spermatozoa, oocytes or embryos. This study demonstrates for the first time the impact of CeO 2 NP on in vitro fertilization, as well as their genotoxicity on mouse spermatozoa and oocytes, at low nanoparticle concentration exposure. Decreased fertilization rates may result from: (1) CeO 2 NP's genotoxicity on gametes; (2) a mechanical effect, disrupting gamete interaction and (3) oxidative stress induced by CeO 2 NP. These results add new and important insights with regard to the reproductive toxicity of nanomaterials requesting urgent evaluation, and support several publications on metal nanoparticles reprotoxicity. Our data highlight the need for in vivo studies after low-dose exposure.

Research paper thumbnail of Poorly soluble cobalt oxide particles trigger genotoxicity via multiple pathways

Particle and fibre toxicology, 2016

Poorly soluble cobalt (II, III) oxide particles (Co3O4P) are believed to induce in vitro cytotoxi... more Poorly soluble cobalt (II, III) oxide particles (Co3O4P) are believed to induce in vitro cytotoxic effects via a Trojan-horse mechanism. Once internalized into lysosomal and acidic intracellular compartments, Co3O4P slowly release a low amount of cobalt ions (Co(2+)) that impair the viability of in vitro cultures. In this study, we focused on the genotoxic potential of Co3O4P by performing a comprehensive investigation of the DNA damage exerted in BEAS-2B human bronchial epithelial cells. Our results demonstrate that poorly soluble Co3O4P enhanced the formation of micronuclei in binucleated cells. Moreover, by comet assay we showed that Co3O4P induced primary and oxidative DNA damage, and by scoring the formation of γ-H2Ax foci, we demonstrated that Co3O4P also generated double DNA strand breaks. By comparing the effects exerted by poorly soluble Co3O4P with those obtained in the presence of soluble cobalt chloride (CoCl2), we demonstrated that the genotoxic effects of Co3O4P are no...

Research paper thumbnail of Expression of adrenomedullin in human epicardial adipose tissue: role of coronary status

AJP: Endocrinology and Metabolism, 2007

Epicardial white adipose tissue (eWAT) is in close contact with coronary vessels and therefore co... more Epicardial white adipose tissue (eWAT) is in close contact with coronary vessels and therefore could alter coronary homeostasis. Adrenomedullin (AM) is a potent vasodilatator and antioxidative peptide which has been shown to play a cytoprotective role in experimental models of acute myocardial infarction. We studied, using immunohistochemistry and qRT-PCR, the expression of AM and its receptors calcitonin receptor-like receptor (CRLR), and receptor activity-modifying protein (RAMP)2 and -3 in paired biopsies of subcutaneous WAT (sWAT) and eWAT obtained from patients with coronary artery disease (CAD) or without CAD (NCAD). In eWAT obtained from NCAD or CAD patients, immunoreactivity for AM, CRLR, and RAMP2 and -3 was detected in blood vessel walls and isolated stromal cells close to adipocytes. Some of the AM positive stromal cells colocalized CD68 immunoreactivity. eWAT from CAD patients showed increased AM immunoreactivity and AM gene expression. CRLR mRNA levels were comparable in sWAT of both groups and decreased by 40-50% in eWAT, irrespectively of the coronary status. RAMP2 mRNA concentrations did not change while RAMP3 mRNA levels increased in sWAT from CAD patients. There was a positive linear relationship between eWAT 11beta-hydroxysteroid dehydrogenase type 1 mRNA (11beta-HSD-1, the enzyme that converts inactive to active glucocorticoids) and AM mRNA. In conclusion, we demonstrate that AM and its receptors are expressed in eWAT. Our data suggest that eWAT AM, which could originate from macrophages, is related to 11beta-HSD-1 expression. AM synthesis, which is increased in eWAT during chronic CAD in humans, can play a cardioprotective role.

Research paper thumbnail of Immediate Postnatal Overfeeding in Rats Programs Aortic Wall Structure Alterations and Metalloproteinases Dysregulation in Adulthood

American journal of hypertension, Jan 6, 2015

Alterations in the nutritional perinatal environment, such as intrauterine growth retardation wit... more Alterations in the nutritional perinatal environment, such as intrauterine growth retardation with subsequent postnatal catch-up growth, program cardiovascular disease in adulthood, possibly through alterations in matrix metalloproteinase (MMP)-2 and -9. However, experimental evidences demonstrating that changes in the nutritional perinatal environment can program MMP-2 and -9 with subsequent alterations of vessel wall are lacking. The current study evaluated whether immediate postnatal overfeeding is able to alter vascular morphological indexes and circulating and/or vascular MMP2-2 and -9 status. Aortic morphology (wall thickness and percentage of incomplete elastin lamellae) and circulating and aortic MMP-2 and -9 activity (measured by gelatin zymography) and aortic MMP-2 and -9 mRNA (measured by reverse transcription polymerase chain reaction (RT-PCR)) were studied in adult male rats overfed (OF) or normofed (NF) during the immediate postnatal period. Postnatal overfeeding induc...

Research paper thumbnail of Chronology of meiosis & synaptonemal complex abnormalities in normal & abnormal spermatogenesis

The Indian Journal of Medical Research

The study was taken up to define criteria of normality for meiosis by assessing the frequency of ... more The study was taken up to define criteria of normality for meiosis by assessing the frequency of meiotic prophase cell types, the frequency of pachytene substage in normal and abnormal spermatogenesis and to determine what synaptonemal complex.

Research paper thumbnail of Chronology of meiosis & synaptonemal complex abnormalities in normal & abnormal spermatogenesis

The Indian journal of medical research, 2009

The study was taken up to define criteria of normality for meiosis by assessing the frequency of ... more The study was taken up to define criteria of normality for meiosis by assessing the frequency of meiotic prophase cell types, the frequency of pachytene substage in normal and abnormal spermatogenesis and to determine what synaptonemal complex. A quantitative and qualitative analysis of the first meiotic prophase was performed in 10 patients presenting with non-obstructive infertility and 10 controls, using dual colour immunocytochemistry with SCP3 and BRCA1 which visualise axial elements and synaptonemal complexes (SC). The respective frequencies of the leptotene, zygotene and pachytene stages as well as the frequencies of the four substages of pachytene were evaluated. The frequencies of the main types of meiotic abnormalities at pachytene were also assessed. The frequencies of leptotene and zygotene stages were significantly higher in patients (7.95 and 9.75%) than in controls (2.30 and 1.45%), whereas the frequency of pachytene was significantly higher in controls than in patien...

Research paper thumbnail of Expression and nutritional regulation of the (pro)renin receptor in rat visceral adipose tissue

Journal of endocrinological investigation, 2011

Early life nutritional environment plays an important role in the development of visceral adipose... more Early life nutritional environment plays an important role in the development of visceral adipose tissue and interacts with nutritional regulations in adulthood, leading to metabolic dysregulations. We hypothesized that the renin-angiotensin system may play a role in the programming-induced development of visceral adipose tissue. We studied, using a model of programming of overweight and glucose intolerance, obtained by post-natal overfeeding with consecutive highfat diet, the status of plasma renin activity and mesenteric adipose renin-angiotensin system, including the recently identified (pro)renin receptor, in adult rats. Post-natal overfeeding or high-fat feeding lead to overweight with increased visceral fat mass and adipocytes surface. When both paradigms were associated, adipocytes surface showed a disproportionate increase. A strong immunoreactivity for (pro)renin receptor was found in stromal cells. Plasma renin activity increased in programmed animals whereas (pro)renin re...

Research paper thumbnail of Chromosomes sexuels et méiose

Gynécologie Obstétrique & Fertilité, 2009

Le comportement des chromosomes sexuels diffère fondamentalement au cours des méioses spermatocyt... more Le comportement des chromosomes sexuels diffère fondamentalement au cours des méioses spermatocytaire et ovocytaire. Dans l'ovocyte, les chromosomes X s'apparient sur toute leur longueur formant un bivalent XX qui ne se distingue pas des bivalents autosomiques, par sa morphologie et son comportement. Chez l'homme, les différences morphologiques et génétiques qui existent entre les chromosomes X et Y vont limiter leur appariement et interdire toute recombinaison génétique excepté dans la région d'homologie PAR1. Au cours du stade pachytène de la prophase I, les chromosomes X et Y se condensent progressivement pour former le corps XY transcriptionnellement inactif à la périphérie du noyau. La condensation du bivalent XY au cours du stade pachytène nous a permis de définir quatre sous-stades pachytène et de localiser le point de contrôle du pachytène entre les sous-stades 2 et 3. Nous avons aussi montré que l'index du pachytène (PI = P1 + P2/P1 + P2 + P3 + P4) était toujours inférieur à 0,50 dans les méioses normales. Alors que le corps XY se décondense au stade diplotène de la prophase I, l'inactivation transcriptionnelle des chromosomes sexuels ou meiotic sex chromosome inactivation (MSCI) persiste jusqu'à la fin de la spermatogenèse. Ce mécanisme d'inactivation fait intervenir des protéines dont un petit nombre a été maintenant identifié, parmi elles, les protéines HP1b et HP1g, impliquées dans l'hétérochromatinisation facultative des chromosomes sexuels. Cependant, l'initiation de la MSCI fait intervenir la phosphorylation de la protéine H2AX par la kinase ATR, elle-même recrutée par BRCA1. Une connaissance plus approfondie des phénomènes d'inactivation des chromosomes sexuels au cours de la méiose mâle permettra de mieux définir les étiologies d'un certain nombre d'infertilités masculines. # 2009 Elsevier Masson SAS. Tous droits réservés.

Research paper thumbnail of A new approach for the oocyte genotoxicity assay: adaptation of comet assay on mouse cumulus-oocyte complexes

Laboratory Animals, 2014

Conventional genotoxicity tests are technically difficult to apply to oocytes, and results obtain... more Conventional genotoxicity tests are technically difficult to apply to oocytes, and results obtained on somatic cells cannot be extrapolated to gametes. We have previously described a comet assay (original-CA) on denuded mouse oocytes, but, in vivo, oocytes are not isolated from their surrounding follicular cells. Our objective was to develop a comet assay on cumulus-oocyte complexes (COC-CA) for a more physiological approach to study the genotoxicity of environmental factors on oocytes. For COC-CA, whole COC were exposed directly to exogenous agents after ovulation and removal from oviducts. Three conditions were studied: a negative control group, and two positive control groups, one of which was exposed to hydrogen peroxide (H2O2) and the other group was incubated with cerium dioxide nanoparticles (CeO2 NPs). With both tests, DNA damage was significant in the presence of both H2O2 and CeO2 NPs compared with the negative control. COC-CA offers an interesting tool for assaying the genotoxicity of environmental agents towards germinal cells. Furthermore, COC-CA is less time-consuming and simplifies the protocol of the original-CA, because COC-CA is easier to perform without the washing-out procedure.

Research paper thumbnail of DNA damage and oxidative stress induced by CeO2 nanoparticles in human dermal fibroblasts: Evidence of a clastogenic effect as a mechanism of genotoxicity

Nanotoxicology, Jan 17, 2014

The broad range of applications of cerium oxide (CeO2) nanoparticles (nano-CeO2) has attracted in... more The broad range of applications of cerium oxide (CeO2) nanoparticles (nano-CeO2) has attracted industrial interest, resulting in greater exposures to humans and environmental systems in the coming years. Their health effects and potential biological impacts need to be determined for risk assessment. The aims of this study were to gain insights into the molecular mechanisms underlying the genotoxic effects of nano-CeO2 in relation with their physicochemical properties. Primary human dermal fibroblasts were exposed to environmentally relevant doses of nano-CeO2 (mean diameter, 7 nm; dose range, 6 × 10(-5)-6 × 10(-3) g/l corresponding to a concentration range of 0.22-22 µM) and DNA damages at the chromosome level were evaluated by genetic toxicology tests and compared to that induced in cells exposed to micro-CeO2 particles (mean diameter, 320 nm) under the same conditions. For this purpose, cytokinesis-blocked micronucleus assay in association with immunofluorescence staining of centr...

Research paper thumbnail of Ultrastructural interactions and genotoxicity assay of cerium dioxide nanoparticles on mouse oocytes

International journal of molecular sciences, 2013

Cerium dioxide nanoparticles (C(e)O₂ ENPs) are on the priority list of nanomaterials requiring ev... more Cerium dioxide nanoparticles (C(e)O₂ ENPs) are on the priority list of nanomaterials requiring evaluation. We performed in vitro assays on mature mouse oocytes incubated with C(e)O₂ ENPs to study (1) physicochemical biotransformation of ENPs in culture medium; (2) ultrastructural interactions with follicular cells and oocytes using Transmission Electron Microscopy (TEM); (3) genotoxicity of C(e)O₂ ENPs on follicular cells and oocytes using a comet assay. DNA damage was quantified as Olive Tail Moment. We show that ENPs aggregated, but their crystal structure remained stable in culture medium. TEM showed endocytosis of C(e)O₂ ENP aggregates in follicular cells. In oocytes, C(e)O₂ ENP aggregates were only observed around the zona pellucida (ZP). The comet assay revealed significant DNA damage in follicular cells. In oocytes, the comet assay showed a dose-related increase in DNA damage and a significant increase only at the highest concentrations. DNA damage decreased significantly bot...

Research paper thumbnail of Detection of 1,N6-ethenoadenosine exocyclic adducts on human lymphocytes by immunocytochemistry

Toxicology Letters, 2011

Acrylonitrile (AN) is a probable human carcinogen and is also a widely used monomer in industries... more Acrylonitrile (AN) is a probable human carcinogen and is also a widely used monomer in industries. AN can be detoxified by glutathione S-transferase (GST) to form glutathione (GSH) conjugates in vivo. If not, it can be metabolically activated by cytochrome P450 2E1 (CYP2E1) to form 2cyanoethylene oxide (CEO), which can also be detoxified by GST to generate GSH conjugates. The conjugates can be further metabolized to N-acetyl-S-(2-cyanoethyl)cysteine (CEMA), N-acetyl-S-(2-hydroxyethyl)cysteine (HEMA), and N-acetyl-S-(1cayno-2-hydroxyethyl)cysteine (CHEMA), respectively. The objective of the study was to quantify the major mercapturic acids (MAs) of AN in urine of AN-exposed workers to validate MAs as biological markers for AN exposures and to study inter-and intra-species differences in AN metabolism. Eighty exposed and 23 non-exposed workers were recruited from three AN-used factories in Taiwan. Personal air samples and urine samples were collected. AN was analyzed by gas chromatographic coupled with flame ionization detector (GC-FID). Urinary MAs were quantified by an ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Data analysis reveals that AN-exposed workers excreted significantly higher MAs levels than non-exposed workers. Linear regression analysis showed significant correlations between AN exposures and MAs concentrations. For those with detectable AN exposures, the ratios of CHEMA/CEMA or (HEMA + CHEMA)/CEMA at post-shift was significantly greater than those at pre-shift, and suggested potential induction of AN metabolism in workers exposed to low concentrations of AN.

Research paper thumbnail of Smoking and benzo(a)pyrene-diol-epoxide DNA adducts in spermatozoa: In smokers, swim-up procedure selects spermatozoa with decreased DNA damage

Toxicology Letters, 2011

Abstracts / Toxicology Letters 205S (2011) S180-S300 S253 10-11 Sprague-Dawley rats were administ... more Abstracts / Toxicology Letters 205S (2011) S180-S300 S253 10-11 Sprague-Dawley rats were administered DMEP (5 ml/kg) on days 6-20 of gestation (GD) at doses of 0 (vehicle: olive oil), 25, 50, 100, 150, or 200 mg/kg/day. Dams were euthanized on GD 21. Live fetuses were weighed and submitted to external examination and internal evaluation of the gonads. No test dams died. Maternal body weight and weight gain were significantly reduced by the end of gestation (GD 18-21) at 150 mg/kg, and during the second half of gestation (after GD 12) at 200 mg/kg/day. However, the corrected body weight gains were comparable across groups and these decreases were attributed to the significantly lower gravid uterine weights. The incidence of post-implantation loss was significantly increased at 150 mg/kg, and reached 87% at 200 mg/kg. There was a pronounced and dose-related decrease in fetal body weight, which was significantly different from control at 100 mg/kg/day and higher doses. Fetal external malformations were observed at 100 mg/kg/day and above. They mainly consisted of anal atresia with absent tail, and edema. No effect was seen on fetal testicular descent. Thus, DMEP was embryotoxic and teratogenic at doses which did not produce overt maternal toxicity.

Research paper thumbnail of In vivo exposure to benzo(a)pyrene induces significant DNA damage in mouse oocytes and cumulus cells

Human Reproduction, 2014

study question: Does in vivo exposure to benzo(a)pyrene (BaP) induce DNA damage in oocytes and cu... more study question: Does in vivo exposure to benzo(a)pyrene (BaP) induce DNA damage in oocytes and cumulus cells (CCs) in mice? summaryanswer: Significant increases in DNA strand breaks in oocytes and CCs and in BaP-induced DNA adducts in CCs were detected in exposed mice compared with controls.

Research paper thumbnail of In smokers, swim-up and discontinuous gradient centrifugation recover spermatozoa with equally lower amounts of DNA damage than spermatozoa obtained from neat semen

Fertility and Sterility, 2011

In smokers, swim-up and discontinuous gradient centrifugation recover spermatozoa with equally lo... more In smokers, swim-up and discontinuous gradient centrifugation recover spermatozoa with equally lower amounts of DNA damage than spermatozoa obtained from neat semen

Research paper thumbnail of Tobacco consumption and benzo(a)pyrene-diol-epoxide–DNA adducts in spermatozoa: in smokers, swim-up procedure selects spermatozoa with decreased DNA damage

Fertility and Sterility, 2011

Objective: To analyze the distribution of benzo(a)pyrene-diol-epoxide (BPDE)-DNA adducts in sperm... more Objective: To analyze the distribution of benzo(a)pyrene-diol-epoxide (BPDE)-DNA adducts in spermatozoa selected and nonselected by a swim-up procedure with relation to smoking habits. Design: Comparative study. Setting: Public university and public university hospital. Patient(s): Seventy-nine men (37 smokers and 42 nonsmokers) who visited an infertility clinic for diagnostic. Intervention(s): Tobacco and environmental exposure assessment, semen sample analysis, swim-up procedure, BPDE-DNA adduct immunolabeling. Main Outcome Measure(s): BPDE-DNA adduct quantification in selected (SEL-SPZ) and nonselected (NONSEL-SPZ) spermatozoa. Data were normalized by using a normalized fluorescence value (NFV).

Research paper thumbnail of P43 La suralimentation post-natale précoce programme un remodelage de la paroi aortique chez le rat adulte

Diabetes & Metabolism, 2010

Research paper thumbnail of Postnatal Programming of Glucocorticoid Metabolism in Rats Modulates High-Fat Diet-Induced Regulation of Visceral Adipose Tissue Glucocorticoid Exposure and Sensitivity and Adiponectin and Proinflammatory Adipokines Gene Expression in Adulthood

Diabetes, 2008

OBJECTIVE-Alterations of the perinatal environment, which lead to increased prevalence of the met... more OBJECTIVE-Alterations of the perinatal environment, which lead to increased prevalence of the metabolic syndrome in adulthood, program an upregulation of systemic and/or adipose tissue glucocorticoid metabolism (11␤-hydroxysteroid dehydrogenase type 1 [11␤-HSD-1]-induced corticosterone reactivation). We hypothesized that postnatal programming could modulate high-fat diet-induced adipose tissue dysregulation in adulthood. RESEARCH DESIGN AND METHODS-We compared the effects of chronic (since weaning) high-or low-fat diet in postnatally normofed (control) or overfed (programmed) rats. RESULTS-Postnatal programming accentuated high-fat dietinduced overweight, insulin resistance, glucose intolerance, and decrease in circulating and epididymal adipose tissue adiponectin. Neither manipulation altered liver function. Postnatal programming or high-fat diet increased systemic corticosterone production, which was not further modified when both manipulations were associated. Postnatal programming suppressed high-fat diet-induced decrease in mesenteric adipose tissue (MAT) glucocorticoid sensitivity and triggered high-fat dietinduced increase in MAT glucocorticoid exposure, subsequent to enhanced MAT 11␤-HSD-1 gene expression. MAT tumor necrosis factor (TNF)-␣, TNF-receptor 1, interleukin (IL)-6, resistin, and plasminogen activator inhibitor-1 mRNAs were not changed by high-fat feeding in control rats and showed a large increase in programmed animals, with this effect further enhanced by highfat diet for TNF-␣ and IL-6. CONCLUSIONS-Our data show for the first time that postnatal manipulation programs high-fat diet-induced upregulation of MAT glucocorticoid exposure, sensitivity, and inflammatory status and therefore reveal the pivotal role of the environment during the perinatal period on the development of diet-induced adipose tissue dysregulation in adulthood. They also urge the need for clinical trials with specific 11␤-HSD-1 inhibitors. Diabetes

Research paper thumbnail of Surveillance biologique des expositions aux hydrocarbures aromatiques polycycliques : de la biométrologie à la biogénotoxicologie et de la génotoxicité somatique à la génotoxicité germinale

Archives des Maladies Professionnelles et de l'Environnement, 2012

Research paper thumbnail of Expression of adrenomedullin in human epicardial adipose tissue: role of coronary status

AJP: Endocrinology and Metabolism, 2007

Epicardial white adipose tissue (eWAT) is in close contact with coronary vessels and therefore co... more Epicardial white adipose tissue (eWAT) is in close contact with coronary vessels and therefore could alter coronary homeostasis. Adrenomedullin (AM) is a potent vasodilatator and antioxidative peptide which has been shown to play a cytoprotective role in experimental models of acute myocardial infarction. We studied, using immunohistochemistry and qRT-PCR, the expression of AM and its receptors calcitonin receptor-like receptor (CRLR), and receptor activity-modifying protein (RAMP)2 and -3 in paired biopsies of subcutaneous WAT (sWAT) and eWAT obtained from patients with coronary artery disease (CAD) or without CAD (NCAD). In eWAT obtained from NCAD or CAD patients, immunoreactivity for AM, CRLR, and RAMP2 and -3 was detected in blood vessel walls and isolated stromal cells close to adipocytes. Some of the AM positive stromal cells colocalized CD68 immunoreactivity. eWAT from CAD patients showed increased AM immunoreactivity and AM gene expression. CRLR mRNA levels were comparable in sWAT of both groups and decreased by 40-50% in eWAT, irrespectively of the coronary status. RAMP2 mRNA concentrations did not change while RAMP3 mRNA levels increased in sWAT from CAD patients. There was a positive linear relationship between eWAT 11beta-hydroxysteroid dehydrogenase type 1 mRNA (11beta-HSD-1, the enzyme that converts inactive to active glucocorticoids) and AM mRNA. In conclusion, we demonstrate that AM and its receptors are expressed in eWAT. Our data suggest that eWAT AM, which could originate from macrophages, is related to 11beta-HSD-1 expression. AM synthesis, which is increased in eWAT during chronic CAD in humans, can play a cardioprotective role.

Research paper thumbnail of Cerium dioxide nanoparticles affect in vitro fertilization in mice

Nanotoxicology, 2015

Due to their catalytic and oxidative properties, cerium dioxide nanoparticles (CeO 2 NPs) are wid... more Due to their catalytic and oxidative properties, cerium dioxide nanoparticles (CeO 2 NPs) are widely used as diesel additive or as promising therapy in cancerology; yet, scarce data are available on their toxicity, and none on their reproductive toxicity. We showed a significant decrease of fertilization rate, assessed on 1272 oocytes, during in vitro fertilization (IVF) carried out in culture medium containing CeO 2 NP at very low concentration (0.01 mg.l À1 ). We also showed significant DNA damage induced in vitro by CeO 2 NP on mouse spermatozoa and oocytes at 0.01 mg.l À1 using Comet assay. Transmission Electron Microscopy did not detect any nanoparticles in the IVF samples at 0.01 mg.l À1 , but showed, at high concentration (100 mg.l À1 ), their endocytosis by the cumulus cells surrounding oocytes and their accumulation along spermatozoa plasma membranes and oocytes zona pellucida. We did not observe any nanoparticles in the cytoplasm of spermatozoa, oocytes or embryos. This study demonstrates for the first time the impact of CeO 2 NP on in vitro fertilization, as well as their genotoxicity on mouse spermatozoa and oocytes, at low nanoparticle concentration exposure. Decreased fertilization rates may result from: (1) CeO 2 NP's genotoxicity on gametes; (2) a mechanical effect, disrupting gamete interaction and (3) oxidative stress induced by CeO 2 NP. These results add new and important insights with regard to the reproductive toxicity of nanomaterials requesting urgent evaluation, and support several publications on metal nanoparticles reprotoxicity. Our data highlight the need for in vivo studies after low-dose exposure.