Accepted Manuscript Title: Mercury toxicokinetics of the healthy human term placenta involve amino acid transporters and ABC transporters Author: Elisabeth Straka Isabella Ellinger Christina Balthasar Matthias Scheinast Jasmin Schatz Tamara Szattler Sonja Bleichert Leila Saleh Martin Kn¨ofler Harald Zeisler Markus Hengstschl¨ager Margit Rosner Hans Salzer Claudia Gundacker PII: DOI: Reference:
S0300-483X(15)30063-9 http://dx.doi.org/doi:10.1016/j.tox.2015.12.005 TOX 51617
To appear in:
Toxicology
Received date: Revised date: Accepted date:
12-10-2015 10-12-2015 23-12-2015
Please cite this article as: Straka, Elisabeth, Ellinger, Isabella, Balthasar, Christina, Scheinast, Matthias, Schatz, Jasmin, Szattler, Tamara, Bleichert, Sonja, Saleh, Leila, Kn¨ofler, Martin, Zeisler, Harald, Hengstschl¨ager, Markus, Rosner, Margit, Salzer, Hans, Gundacker, Claudia, Mercury toxicokinetics of the healthy human term placenta involve amino acid transporters and ABC transporters.Toxicology http://dx.doi.org/10.1016/j.tox.2015.12.005 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Mercury toxicokinetics of the healthy human term placenta involve amino acid transporters and ABC transporters Short running title: Mercury toxicokinetics of the human placenta
Elisabeth Straka1&, Isabella Ellinger2&, Christina Balthasar1, Matthias Scheinast1, Jasmin Schatz1, Tamara Szattler1, Sonja Bleichert1, Leila Saleh3, Martin Knöfler3, Harald Zeisler3, Markus Hengstschläger1, Margit Rosner1, Hans Salzer4, Claudia Gundacker1§
1
Institute of Medical Genetics, Medical University Vienna, Vienna, Austria
2
Department of Pathophysiology and Allergy Research, Medical University Vienna, Vienna,
Austria 3
Department of Obstetrics and Fetal-maternal Medicine, Medical University Vienna, Vienna,
Austria 4
Clinic for Pediatrics and Adolescent Medicine, University Hospital Tulln, Tulln, Austria
&
shared first authors
§
Corresponding author
Claudia Gundacker: Medical University Vienna, Institute of Medical Genetics, Waehringer Strasse 10, A-1090 Vienna, Austria, Europe, Phone. +43 1 40160 56503, Email. [email protected] Highlights It is known that MeHg is able to pass the placenta and to affect fetal brain development. Uptake and efflux transporters were examined in human primary trophoblast cells and BeWo cells. Involvement in mercury transfer was assessed by measurement of cellular mercury content upon siRNA mediated gene knockdown. Localization of transporters was determined by immunofluorescence microscopy. LAT1 and rBAT at the apical membrane of the syncytiotrophoblast (STB) are involved in MeHg uptake. MRP1 located at basal membrane of STB mediates mercury efflux. Abstract
BACKGROUND: The capacity of the human placenta to handle exogenous stressors is poorly understood. The heavy metal mercury is well-known to pass the placenta and to affect brain development. An active transport across the placenta has been assumed. The underlying mechanisms however are virtually unknown. OBJECTIVES: Uptake and efflux transporters (17 candidate proteins) assumed to play a key role in placental mercury transfer were examined for expression, localization and function in human primary trophoblast cells and the trophoblast-derived choriocarcinoma cell line BeWo. METHODS: To prove involvement of the transporters, we used small interfering RNA (siRNA) and exposed cells to methylmercury (MeHg). Total mercury contents of cells were analyzed by cold vapor-Atomic Fluorescence Spectrometry (CV-AFS). Localization of the proteins in human term placenta sections was determined via immunofluorescence microscopy. RESULTS: We found the amino acid transporter subunits L-Type Amino Acid Transporter (LAT)1 and rBAT (related to b0,+ type amino acid transporter) as well as the efflux transporter Multidrug Resistance Associated Protein (MRP)1 to be involved in mercury kinetics of trophoblast cells (t-Test P
S0300-483X(15)30063-9 http://dx.doi.org/doi:10.1016/j.tox.2015.12.005 TOX 51617
To appear in:
Toxicology
Received date: Revised date: Accepted date:
12-10-2015 10-12-2015 23-12-2015
Please cite this article as: Straka, Elisabeth, Ellinger, Isabella, Balthasar, Christina, Scheinast, Matthias, Schatz, Jasmin, Szattler, Tamara, Bleichert, Sonja, Saleh, Leila, Kn¨ofler, Martin, Zeisler, Harald, Hengstschl¨ager, Markus, Rosner, Margit, Salzer, Hans, Gundacker, Claudia, Mercury toxicokinetics of the healthy human term placenta involve amino acid transporters and ABC transporters.Toxicology http://dx.doi.org/10.1016/j.tox.2015.12.005 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Mercury toxicokinetics of the healthy human term placenta involve amino acid transporters and ABC transporters Short running title: Mercury toxicokinetics of the human placenta
Elisabeth Straka1&, Isabella Ellinger2&, Christina Balthasar1, Matthias Scheinast1, Jasmin Schatz1, Tamara Szattler1, Sonja Bleichert1, Leila Saleh3, Martin Knöfler3, Harald Zeisler3, Markus Hengstschläger1, Margit Rosner1, Hans Salzer4, Claudia Gundacker1§
1
Institute of Medical Genetics, Medical University Vienna, Vienna, Austria
2
Department of Pathophysiology and Allergy Research, Medical University Vienna, Vienna,
Austria 3
Department of Obstetrics and Fetal-maternal Medicine, Medical University Vienna, Vienna,
Austria 4
Clinic for Pediatrics and Adolescent Medicine, University Hospital Tulln, Tulln, Austria
&
shared first authors
§
Corresponding author
Claudia Gundacker: Medical University Vienna, Institute of Medical Genetics, Waehringer Strasse 10, A-1090 Vienna, Austria, Europe, Phone. +43 1 40160 56503, Email. [email protected] Highlights It is known that MeHg is able to pass the placenta and to affect fetal brain development. Uptake and efflux transporters were examined in human primary trophoblast cells and BeWo cells. Involvement in mercury transfer was assessed by measurement of cellular mercury content upon siRNA mediated gene knockdown. Localization of transporters was determined by immunofluorescence microscopy. LAT1 and rBAT at the apical membrane of the syncytiotrophoblast (STB) are involved in MeHg uptake. MRP1 located at basal membrane of STB mediates mercury efflux. Abstract
BACKGROUND: The capacity of the human placenta to handle exogenous stressors is poorly understood. The heavy metal mercury is well-known to pass the placenta and to affect brain development. An active transport across the placenta has been assumed. The underlying mechanisms however are virtually unknown. OBJECTIVES: Uptake and efflux transporters (17 candidate proteins) assumed to play a key role in placental mercury transfer were examined for expression, localization and function in human primary trophoblast cells and the trophoblast-derived choriocarcinoma cell line BeWo. METHODS: To prove involvement of the transporters, we used small interfering RNA (siRNA) and exposed cells to methylmercury (MeHg). Total mercury contents of cells were analyzed by cold vapor-Atomic Fluorescence Spectrometry (CV-AFS). Localization of the proteins in human term placenta sections was determined via immunofluorescence microscopy. RESULTS: We found the amino acid transporter subunits L-Type Amino Acid Transporter (LAT)1 and rBAT (related to b0,+ type amino acid transporter) as well as the efflux transporter Multidrug Resistance Associated Protein (MRP)1 to be involved in mercury kinetics of trophoblast cells (t-Test P
