TY - JOUR
T1 - Chronic administration of Benzo(a)pyrene induces memory impairment and anxiety-like behavior and increases of NR2B DNA methylation
AU - Zhang, Wenping
AU - Tian, Fengjie
AU - Zheng, Jinping
AU - Li, Senlin
AU - Qiang, Mei
N1 - Publisher Copyright:
© 2016 Zhang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2016/2
Y1 - 2016/2
N2 - Background: Recently, an increasing number of human and animal studies have reported that exposure to benzo(a)pyrene (BaP) induces neurological abnormalities and is also associated with adverse effects, such as tumor formation, immunosuppression, teratogenicity, and hormonal disorders. However, the exact mechanisms underlying BaP-induced impairment of neurological function remain unclear. The aim of this study was to examine the regulating mechanisms underlying the impact of chronic BaP exposure on neurobehavioral performance. Methods: C57BL mice received either BaP in different doses (1.0, 2.5, 6.25 mg/kg) or olive oil twice a week for 90 days. Memory and emotional behaviors were evaluated using Y-maze and open-field tests, respectively. Furthermore, levels of mRNA expression were measured by using qPCR, and DNA methylation of NMDA receptor 2B subunit (NR2B) was examined using bisulfate pyrosequencing in the prefrontal cortex and hippocampus. Results: Compared to controls, mice that received BaP (2.5, 6.25 mg/kg) showed deficits in shortterm memory and an anxiety-like behavior. These behavioral alterations were associated with a down-regulation of the NR2B gene and a concomitant increase in the level of DNA methylation in the NR2B promoter in the two brain regions. Conclusions: Chronic BaP exposure induces an increase in DNA methylation in the NR2B gene promoter and down-regulates NR2B expression, which may contribute to its neurotoxic effects on behavioral performance. The results suggest that NR2B vulnerability represents a target for environmental toxicants in the brain.
AB - Background: Recently, an increasing number of human and animal studies have reported that exposure to benzo(a)pyrene (BaP) induces neurological abnormalities and is also associated with adverse effects, such as tumor formation, immunosuppression, teratogenicity, and hormonal disorders. However, the exact mechanisms underlying BaP-induced impairment of neurological function remain unclear. The aim of this study was to examine the regulating mechanisms underlying the impact of chronic BaP exposure on neurobehavioral performance. Methods: C57BL mice received either BaP in different doses (1.0, 2.5, 6.25 mg/kg) or olive oil twice a week for 90 days. Memory and emotional behaviors were evaluated using Y-maze and open-field tests, respectively. Furthermore, levels of mRNA expression were measured by using qPCR, and DNA methylation of NMDA receptor 2B subunit (NR2B) was examined using bisulfate pyrosequencing in the prefrontal cortex and hippocampus. Results: Compared to controls, mice that received BaP (2.5, 6.25 mg/kg) showed deficits in shortterm memory and an anxiety-like behavior. These behavioral alterations were associated with a down-regulation of the NR2B gene and a concomitant increase in the level of DNA methylation in the NR2B promoter in the two brain regions. Conclusions: Chronic BaP exposure induces an increase in DNA methylation in the NR2B gene promoter and down-regulates NR2B expression, which may contribute to its neurotoxic effects on behavioral performance. The results suggest that NR2B vulnerability represents a target for environmental toxicants in the brain.
UR - http://www.scopus.com/inward/record.url?scp=84960510570&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84960510570&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0149574
DO - 10.1371/journal.pone.0149574
M3 - Article
C2 - 26901155
AN - SCOPUS:84960510570
VL - 11
JO - PLoS One
JF - PLoS One
SN - 1932-6203
IS - 2
M1 - e0149574
ER -