BACKGROUND: Di-(2-ethylhexyl)-phthalate (DEHP) is a widely used plasticizer that imparts flexibility to polyvinyl chloride. We have recently reported that clinically relevant concentrations of DEHP can affect electrical coupling between cardiac myocytes causing significant rhythm disturbances. The underlying causes for this effect are currently unknown. OBJECTIVES: To use data on global mRNA expression as a tool to reveal possible pathways leading to arrhythmogenic effects of DEHP. METHODS: Rat neonatal cardiomyocytes were treated with 50 μg/mL DEHP for 72 h. Extracted RNA samples were hybridized onto Affymetrix Rat Gene 1.0 ST arrays. The mRNA expression of a subset of genes was validated by qRT-PCR. In a second set of experiments, cells were treated in a concentration dependent manner to identify genes affected by low DEHP concentrations. RESULTS: DEHP exposure is associated with global changes in mRNA expression, with differentially expressed genes overrepresented in 47 Gene Ontology categories. Modified expression was detected for genes associated with cell electrical activity, calcium handling, adhesion and microtubular transport. For a number of key proteins, including kinesin, TGFβ2, α-tubulin, and α1 & β1 integrins, changes in mRNA levels were confirmed on the level of the protein expression. A number of genes associated with cell adhesion and electrical activity were identified as early DEHP targets as they were affected by concentrations as low as 1 μg/mL. CONCLUSIONS: Exposure of neonatal rat cardiomyocytes to clinically relevant DEHP concentrations leads to global changes in mRNA expression. These changes help to explain the arrhythmogenic effects of phthalates on these cells.
BACKGROUND:Di-(2-ethylhexyl)-phthalate (DEHP) is a widely used plasticizer that imparts flexibility to polyvinyl chloride. We have recently reported that clinically relevant concentrations of DEHP can affect electrical coupling between cardiac myocytes causing significant rhythm disturbances. The underlying causes for this effect are currently unknown. OBJECTIVES: To use data on global mRNA expression as a tool to reveal possible pathways leading to arrhythmogenic effects of DEHP. METHODS:Rat neonatal cardiomyocytes were treated with 50 μg/mL DEHP for 72 h. Extracted RNA samples were hybridized onto Affymetrix Rat Gene 1.0 ST arrays. The mRNA expression of a subset of genes was validated by qRT-PCR. In a second set of experiments, cells were treated in a concentration dependent manner to identify genes affected by low DEHP concentrations. RESULTS:DEHP exposure is associated with global changes in mRNA expression, with differentially expressed genes overrepresented in 47 Gene Ontology categories. Modified expression was detected for genes associated with cell electrical activity, calcium handling, adhesion and microtubular transport. For a number of key proteins, including kinesin, TGFβ2, α-tubulin, and α1 & β1 integrins, changes in mRNA levels were confirmed on the level of the protein expression. A number of genes associated with cell adhesion and electrical activity were identified as early DEHP targets as they were affected by concentrations as low as 1 μg/mL. CONCLUSIONS: Exposure of neonatal rat cardiomyocytes to clinically relevant DEHP concentrations leads to global changes in mRNA expression. These changes help to explain the arrhythmogenic effects of phthalates on these cells.
Authors: S Hinan Ahmed; Leslie L Clark; Weems R Pennington; Carson S Webb; D Dirk Bonnema; Amy H Leonardi; Catherine D McClure; Francis G Spinale; Michael R Zile Journal: Circulation Date: 2006-04-24 Impact factor: 29.690
Authors: Robin M Shaw; Alex J Fay; Manojkumar A Puthenveedu; Mark von Zastrow; Yuh-Nung Jan; Lily Y Jan Journal: Cell Date: 2007-02-09 Impact factor: 41.582
Authors: Dmitry Terentyev; Steven E Cala; Timothy D Houle; Serge Viatchenko-Karpinski; Inna Gyorke; Radmila Terentyeva; Simon C Williams; Sandor Gyorke Journal: Circ Res Date: 2005-02-24 Impact factor: 17.367
Authors: Nagesh Chopra; Prince J Kannankeril; Tao Yang; Thinn Hlaing; Izabela Holinstat; Kristen Ettensohn; Karl Pfeifer; Brandy Akin; Larry R Jones; Clara Franzini-Armstrong; Björn C Knollmann Journal: Circ Res Date: 2007-07-26 Impact factor: 17.367
Authors: Nikki Gillum Posnack; Luther M Swift; Matthew W Kay; Norman H Lee; Narine Sarvazyan Journal: Environ Health Perspect Date: 2012-06-06 Impact factor: 9.031