The Pharmacology & Physiology Department, The George Washington University, 2300 Eye Street, Washington, DC 20037, USA.
Toxicology. 2011 Jan 11;279(1-3):54-64. doi: 10.1016/j.tox.2010.09.007. Epub 2010 Oct 8.
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.
To use data on global mRNA expression as a tool to reveal possible pathways leading to arrhythmogenic effects of DEHP.
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.
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.
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.
邻苯二甲酸二（2-乙基己基）酯（DEHP）是一种广泛使用的增塑剂，可赋予聚氯乙烯柔韧性。我们最近报道，临床相关浓度的 DEHP 可影响心肌细胞之间的电偶联，导致明显的节律紊乱。这种作用的潜在原因目前尚不清楚。
利用全球 mRNA 表达数据作为揭示导致 DEHP 致心律失常作用的可能途径的工具。
用 50μg/ml 的 DEHP 处理新生大鼠心肌细胞 72 小时。提取 RNA 样品并与 Affymetrix Rat Gene 1.0 ST 芯片杂交。通过 qRT-PCR 验证了一组亚基因的 mRNA 表达。在第二组实验中，以浓度依赖的方式处理细胞，以确定受低 DEHP 浓度影响的基因。
DEHP 暴露与 mRNA 表达的全局变化相关，差异表达的基因在 47 个基因本体论类别中过度表达。与细胞电活动、钙处理、粘附和微管运输相关的基因的表达发生改变。对于许多关键蛋白，包括驱动蛋白、TGFβ2、α-微管蛋白和α1 & β1 整合素，蛋白表达水平也证实了 mRNA 水平的变化。一些与细胞粘附和电活动相关的基因被确定为早期 DEHP 靶标，因为它们在低至 1μg/ml 的浓度下就受到了影响。
新生大鼠心肌细胞暴露于临床相关浓度的 DEHP 会导致 mRNA 表达的全局变化。这些变化有助于解释邻苯二甲酸盐对这些细胞的致心律失常作用。
