[Effects of fluoride on neural cell adhesion molecules mRNA and protein expression levels in primary rat hippocampal neurons].
OBJECTIVE
To investigate the effects of fluoride on the growth and viability, and mRNA and protein expression levels of neural cell adhesion molecules (NCAM) in primary rat hippocampal neurons.


METHODS
The growth and development, the rate of cell survivor, and the mRNA and protein expression levels of NCAM were measured by MTT, RT-PCR, and Western blot respectively after the hippocampal neurons were incubated with 20, 40, and 80 microg/ml sodium fluoride for 24 hours in vitro.


RESULTS
As compared with the control group, the number of cells, the length and number of neuritis, and rate of cell survivor were significantly decreased in 80 microg/ml fluoride-treated group (P < 0.05). The mRNA expression levels of NCAM in 40 and 80 microg/ml fluoride-treated groups were significantly lower than that in the control group and decreased with the increasing fluoride concentration. Compared with the control group, the mRNA expression level of NCAM in 20 microg/ml fluoride-treated group was decreased, but the difference was not statistically significant (P > 0.05). The NCAM-180 protein expression levels in 40 and 80 microg/ml fluoride-treated groups, the NCAM-140 protein expression levels in all fluoride-treated groups, and NCAM-120 protein expression level in 80 microg/ml fluoride-treated group were significantly lower than those in the control group (P < 0.05, P < 0.05, P < 0.05, respectively).


CONCLUSIONS
Fluoride might restrain the growth and survival of rat hippocampal neurons, and decrease mRNA and protein expression levels of NCAM. The impairment of developmental hippocampus might be one of the neurotoxicant target sites for fluoride toxicity.
Xia
Tao
T
Department of Occupational and Environmental Health (MOE Key Lab of Environment and Health), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Zhang
Ming
M
He
Wei-Hong
WH
He
Ping
P
Wang
Ai-Guo
AG
D000818:Animals; D002478:Cells, Cultured; D005459:Fluorides / Q000633:toxicity*; D015870:Gene Expression; D006624:Hippocampus / Q000166:cytology; D039842:Neural Cell Adhesion Molecule L1 / Q000096:biosynthesis* / Q000235:genetics; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley
D039842:Neural Cell Adhesion Molecule L1; D012333:RNA, Messenger; D005459:Fluorides