東華大學圖書館 |

Placental Cell Responses to Trichloroethylene Metabolite S-(1, 2-dichlorovinyl)-l-cysteine Exposure.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Placental Cell Responses to Trichloroethylene Metabolite S-(1, 2-dichlorovinyl)-l-cysteine Exposure./
Author:	Elkin, Elana R.
Published:	Ann Arbor : ProQuest Dissertations & Theses, : 2019,
Description:	226 p.
Notes:	Source: Dissertations Abstracts International, Volume: 81-08, Section: B.
Contained By:	Dissertations Abstracts International81-08B.
Subject:	Public health. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=27614514
ISBN:	9781392664452

Placental Cell Responses to Trichloroethylene Metabolite S-(1, 2-dichlorovinyl)-l-cysteine Exposure.
Elkin, Elana R.

Placental Cell Responses to Trichloroethylene Metabolite S-(1, 2-dichlorovinyl)-l-cysteine Exposure. - Ann Arbor : ProQuest Dissertations & Theses, 2019 - 226 p.

Source: Dissertations Abstracts International, Volume: 81-08, Section: B.

Thesis (Ph.D.)--University of Michigan, 2019.

This item must not be sold to any third party vendors.

The placenta provides the critical interface between mother and fetus, regulating fetal in utero development through the exchange of hormones nutrients, waste, and oxygen. Given its critical role, abnormalities of the placenta substantially increase the risk of adverse birth outcomes. Although exposure to environmental contaminants is increasingly thought to elevate risk for adverse birth outcomes, the mechanism(s) by which toxicants adversely impact pregnancy remain largely unknown. Recent epidemiology studies found that maternal exposure to trichloroethylene (TCE), an industrial solvent and pervasive environmental contaminant, was associated with increased risk for low birth weight and preterm birth. This thesis investigated the effects of the TCE metabolite S-(1, 2-dichlorovinyl)-L-cysteine on extravillous trophoblasts, specific cells that play a pivotal role in tissue and maternal spiral artery remodeling during placental development.DCVC effects on placental cells were studied using the HTR-8/SVneo immortalized extravillous trophoblast cell line. Following exposure to 5-20 µM DCVC for 6 or 12 h, targeted metabolomics detected changes in intracellular concentrations of metabolites from different energy metabolism pathways. Although no change in ATP levels were observed, glucose metabolism perturbations were detected that included a time-dependent accumulation of glucose-6-phosphate+frutose-6-phosphate (G6P+F6P), as well as independent shunting of glucose intermediates. Furthermore, DCVC treatment stimulated compensatory utilization of glycerol, lipid and amino acid amino metabolism to provide intermediate substrates entering downstream glycolysis or the tricarboxylic cycle. In addition, transcriptomics analysis revealed hundreds of differentially expressed genes with exposure to 20 µM DCVC for 12 h (FDR< 0.1 and fold-change 1.5). Furthermore, gene set enrichment analyses demonstrated that the most substantially altered molecular signaling pathway was the EIF2α/ATF4 Integrated Stress Response (ISR), accompanied by decreased global protein synthesis. However, no changes in cell cycle progression or proliferation were detected, suggesting that a generally successful adaptive process occurred after 12 h of DCVC treatment.In order to further investigate DCVC effects, HTR-8/SVneo cells were treated with 10-20 µM DCVC for mitochondrial bioenergentics experiments, or 10-100 µM DCVC for apoptosis experiments. Using the Seahorse XF Analyzer allowed evaluation of key aspects of mitochondrial function with concurrent real-time monitoring of oxygen consumption rates and extracellular acidification rates. Elevated basal oxygen consumption rate, mitochondrial proton leak and sustained energy coupling deficiency occurred after 6 h of exposure to 20 µM DCVC, whereas 12 h of exposure to DCVC decreased mitochondrial-dependent basal, ATP-linked and maximum oxygen consumption rates. Moreover, mitochondrial membrane potential dissipated after 12 h of exposure to 20 µM DCVC, as detected with the TMRE fluorochrome. The antioxidant (±)-α-tocopherol attenuated DCVC-stimulated mitochondrial membrane depolarization and caspase 3+7 activity but failed to rescue oxygen consumption perturbations. Furthermore, evaluation of DCVC-stimulated apoptosis revealed that DCVC simultaneously activated the mitochondrial-mediated and cell surface receptor-mediated apoptotic pathways, most likely via co-regulatory p53 signaling. Finally, mitochondria-centered crosstalk between the two activated pathways appeared to amplify the effect on the overall apoptotic response. Taken together, these findings showed progressive defects in mitochondrial function and suggest mitochondria as the primary intracellular targets for DCVC-mediated cytotoxicity in placental cells.Collectively, the series of studies presented in this thesis detail responses to the TCE metabolite DCVC in placental cells, contributing to our understanding of the toxicological mechanism of action of TCE. These new insights support epidemiology studies by providing plausible biological explanations for observed association with pregnancy complications and adverse birth outcomes.

ISBN: 9781392664452Subjects--Topical Terms:

534748
Public health.
Subjects--Index Terms:

Trichloroethylene

Placental Cell Responses to Trichloroethylene Metabolite S-(1, 2-dichlorovinyl)-l-cysteine Exposure.
LDR:05472nmm a2200385 4500 001 2272937
005 20201105110303.5
008 220629s2019 ||||||||||||||||| ||eng d
020 $a 9781392664452
035 $a (MiAaPQ)AAI27614514
035 $a (MiAaPQ)umichrackham002400
035 $a AAI27614514
040 $a MiAaPQ $c MiAaPQ
100 1 $a Elkin, Elana R. $3 3550360
245 1 0 $a Placental Cell Responses to Trichloroethylene Metabolite S-(1, 2-dichlorovinyl)-l-cysteine Exposure.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2019
300 $a 226 p.
500 $a Source: Dissertations Abstracts International, Volume: 81-08, Section: B.
500 $a Advisor: Loch-Caruso, Rita.
502 $a Thesis (Ph.D.)--University of Michigan, 2019.
506 $a This item must not be sold to any third party vendors.
506 $a This item must not be added to any third party search indexes.
520 $a The placenta provides the critical interface between mother and fetus, regulating fetal in utero development through the exchange of hormones nutrients, waste, and oxygen. Given its critical role, abnormalities of the placenta substantially increase the risk of adverse birth outcomes. Although exposure to environmental contaminants is increasingly thought to elevate risk for adverse birth outcomes, the mechanism(s) by which toxicants adversely impact pregnancy remain largely unknown. Recent epidemiology studies found that maternal exposure to trichloroethylene (TCE), an industrial solvent and pervasive environmental contaminant, was associated with increased risk for low birth weight and preterm birth. This thesis investigated the effects of the TCE metabolite S-(1, 2-dichlorovinyl)-L-cysteine on extravillous trophoblasts, specific cells that play a pivotal role in tissue and maternal spiral artery remodeling during placental development.DCVC effects on placental cells were studied using the HTR-8/SVneo immortalized extravillous trophoblast cell line. Following exposure to 5-20 µM DCVC for 6 or 12 h, targeted metabolomics detected changes in intracellular concentrations of metabolites from different energy metabolism pathways. Although no change in ATP levels were observed, glucose metabolism perturbations were detected that included a time-dependent accumulation of glucose-6-phosphate+frutose-6-phosphate (G6P+F6P), as well as independent shunting of glucose intermediates. Furthermore, DCVC treatment stimulated compensatory utilization of glycerol, lipid and amino acid amino metabolism to provide intermediate substrates entering downstream glycolysis or the tricarboxylic cycle. In addition, transcriptomics analysis revealed hundreds of differentially expressed genes with exposure to 20 µM DCVC for 12 h (FDR< 0.1 and fold-change 1.5). Furthermore, gene set enrichment analyses demonstrated that the most substantially altered molecular signaling pathway was the EIF2α/ATF4 Integrated Stress Response (ISR), accompanied by decreased global protein synthesis. However, no changes in cell cycle progression or proliferation were detected, suggesting that a generally successful adaptive process occurred after 12 h of DCVC treatment.In order to further investigate DCVC effects, HTR-8/SVneo cells were treated with 10-20 µM DCVC for mitochondrial bioenergentics experiments, or 10-100 µM DCVC for apoptosis experiments. Using the Seahorse XF Analyzer allowed evaluation of key aspects of mitochondrial function with concurrent real-time monitoring of oxygen consumption rates and extracellular acidification rates. Elevated basal oxygen consumption rate, mitochondrial proton leak and sustained energy coupling deficiency occurred after 6 h of exposure to 20 µM DCVC, whereas 12 h of exposure to DCVC decreased mitochondrial-dependent basal, ATP-linked and maximum oxygen consumption rates. Moreover, mitochondrial membrane potential dissipated after 12 h of exposure to 20 µM DCVC, as detected with the TMRE fluorochrome. The antioxidant (±)-α-tocopherol attenuated DCVC-stimulated mitochondrial membrane depolarization and caspase 3+7 activity but failed to rescue oxygen consumption perturbations. Furthermore, evaluation of DCVC-stimulated apoptosis revealed that DCVC simultaneously activated the mitochondrial-mediated and cell surface receptor-mediated apoptotic pathways, most likely via co-regulatory p53 signaling. Finally, mitochondria-centered crosstalk between the two activated pathways appeared to amplify the effect on the overall apoptotic response. Taken together, these findings showed progressive defects in mitochondrial function and suggest mitochondria as the primary intracellular targets for DCVC-mediated cytotoxicity in placental cells.Collectively, the series of studies presented in this thesis detail responses to the TCE metabolite DCVC in placental cells, contributing to our understanding of the toxicological mechanism of action of TCE. These new insights support epidemiology studies by providing plausible biological explanations for observed association with pregnancy complications and adverse birth outcomes.
590 $a School code: 0127.
650 4 $a Public health. $3 534748
650 4 $a Environmental health. $3 543032
650 4 $a Toxicology. $3 556884
653 $a Trichloroethylene
653 $a Placentas
653 $a Extravillous trophoblasts
653 $a Reproductive toxicology
690 $a 0383
690 $a 0470
690 $a 0573
710 2 $a University of Michigan. $b Toxicology. $3 3550255
773 0 $t Dissertations Abstracts International $g 81-08B.
790 $a 0127
791 $a Ph.D.
792 $a 2019
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=27614514