US EPA

3515170 

Journal Article 

Dibutyl Phthalate (DBP)-Induced Apoptosis and Neurotoxicity are Mediated via the Aryl Hydrocarbon Receptor (AhR) but not by Estrogen Receptor Alpha (ERα), Estrogen Receptor Beta (ERβ), or Peroxisome Proliferator-Activated Receptor Gamma (PPARγ) in Mouse Cortical Neurons 

Wójtowicz, AK; Szychowski, KA; Wnuk, A; Kajta, M 

2017 

1 

Neurotoxicity Research
ISSN: 1029-8428
EISSN: 1476-3524 

31 

1 

77-89 

English 

27581038 

10.1007/s12640-016-9665-x 

WOS:000392209200007 

Dibutyl phthalate (di-n-butyl phthalate, DBP) is one of the most commonly used phthalate esters. DBP is widely used as a plasticizer in a variety of household industries and consumer products. Because phthalates are not chemically bound to products, they can easily leak out to enter the environment. DBP can pass through the placental and blood-brain barriers due to its chemical structure, but little is known about its mechanism of action in neuronal cells. This study demonstrated the toxic and apoptotic effects of DBP in mouse neocortical neurons in primary cultures. DBP stimulated caspase-3 and LDH activities as well as ROS formation in a concentration (10 nM-100 µM) and time-dependent (3-48 h) manner. DBP induced ROS formation at nanomolar concentrations, while it activated caspase-3 and LDH activities at micromolar concentrations. The biochemical effects of DBP were accompanied by decreased cell viability and induction of apoptotic bodies. Exposure to DBP reduced Erα and Pparγ mRNA expression levels, which were inversely correlated with protein expression of the receptors. Treatment with DBP enhanced Ahr mRNA expression, which was reflected by the increased AhR protein level observed at 3 h after exposure. ERα, ERβ, and PPARγ antagonists stimulated DBP-induced caspase-3 and LDH activities. AhR silencing demonstrated that DBP-induced apoptosis and neurotoxicity are mediated by AhR, which is consistent with the results from DBP-induced enhancement of AhR mRNA and protein expression. Our study showed that AhR is involved in DBP-induced apoptosis and neurotoxicity, while the ERs and PPARγ signaling pathways are impaired by the phthalate. 

Animals; Apoptosis/drug effects/physiology; Caspase 3/metabolism; Cell Survival/drug effects/physiology; Cells, Cultured; Cerebral Cortex/drug effects/metabolism/pathology; Dibutyl Phthalate/toxicity; Dose-Response Relationship, Drug; Estrogen Receptor alpha/antagonists & inhibitors/metabolism; Estrogen Receptor beta/antagonists & inhibitors/metabolism; Neurons/drug effects/metabolism/pathology; PPAR gamma/antagonists & inhibitors/metabolism; RNA, Messenger/metabolism; Reactive Oxygen Species/metabolism; Receptors, Aryl Hydrocarbon/antagonists & inhibitors/metabolism; Time Factors; Apoptosis; Neuron; PPARγ; Phthalate; 2286E5R2KE