Maternal low-level lead exposure reduces the expression of PSA-NCAM and the activity of sialyltransferase in the hippocampi of neonatal rat pups.
Highly polysialylated neural cell adhesion molecule (PSA-NCAM) is transiently expressed specifically in newly generated cells, and is important for cell migration and neurite outgrowth. Developmental lead (Pb) exposure has been considered to affect the expression of PSA-NCAM, which contributes to the neurotoxicity of Pb exposure. However, the effect of maternal low-level Pb exposure on the expression of PSA-NCAM in neonatal rat pups has not been reported. In the present study, female Wistar rats were exposed to vehicle or different dosages of lead chloride (0.5-4mM PbCl2) 2 weeks before and during pregnancy. This exposure protocol resulted in neonatal rat pups blood Pb levels up to 12.12+/-0.38 microg/dl, and hippocampal Pb levels up to 9.22+/-0.81 microg/g at postnatal day 1 (PND 1). Immunohistochemistry analysis and Western blot analysis revealed that the expressions of PSA-NCAM and NCAM in the hippocampi of neonatal rat pups at PND 1 were significantly reduced by the maternal low-level Pb exposures. Furthermore, the mRNA levels of NCAM and polysialyltransferases (STX and PST), measured by the fluorescent real-time quantitative RT-PCR, dosage-dependently and significantly decreased by 13.26-37.62%, 25.17-59.67%, and 10.78-47.81%, respectively. In addition, the sialyltransferase activity in neonatal rat pups was significantly reduced by 6.23-32.50% in the presence of the low-level Pb exposure, too. Taken together, these results suggest that maternal low-level Pb exposure reduces the expression of PSA-NCAM, NCAM, and the activity of sialyltransferase in the hippocampi of neonatal rat pups, which might contribute to the learning and memory impairments in the developmental pups following maternal low-level Pb exposure.
Hu
Qiansheng
Q
Department of Preventive Medicine, School of Public Health, Sun Yat-Sen University, Guangzhou, China. huqsh@mail.sysu.edu.cn
Fu
Hongjun
H
Ren
Tieling
T
Wang
Shuyu
S
Zhou
Wei
W
Song
Hong
H
Han
Yifan
Y
Dong
Shengzhang
S
D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D004305:Dose-Response Relationship, Drug; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects*; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D007854:Lead / Q000633:toxicity*; D008297:Male; D039842:Neural Cell Adhesion Molecule L1 / Q000235:genetics / Q000378:metabolism*; D019006:Neural Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced* / Q000473:pathology*; D051381:Rats; D017208:Rats, Wistar; D022621:Shiga Toxin / Q000235:genetics / Q000378:metabolism; D012794:Sialic Acids / Q000235:genetics / Q000378:metabolism*; D012799:Sialyltransferases / Q000235:genetics / Q000378:metabolism*
D039842:Neural Cell Adhesion Molecule L1; D019006:Neural Cell Adhesion Molecules; D012794:Sialic Acids; C103469:polysialyl neural cell adhesion molecule; D007854:Lead; C029891:lead chloride; D022621:Shiga Toxin; D012799:Sialyltransferases