In vitro neurotoxicity of PBDE-99: immediate and concentration-dependent effects on protein expression in cerebral cortex cells.
Polybrominated diphenyl ethers (PBDEs) are commonly used flame retardants in various consumer products. Pre- and postnatal exposure to congeners of PBDEs disrupts normal brain development in rodents. Two-dimensional difference gel electrophoresis (2D-DIGE) was used to analyze concentration-dependent differences in protein expression in cultured cortical cells isolated from rat fetuses (GD 21) after 24 h exposure to PBDE-99 (3, 10, or 30 microM). Changes on a post-translational level were studied using a 1 h exposure to 30 microM PBDE-99. The effects of 24 h exposure to 3 and 30 microM PBDE-99 on mRNA levels were measured using oligonucleotide microarrays. A total of 62, 46, and 443 proteins were differentially expressed compared to controls after 24 h of exposure to 3, 10, and 30 microM PDBE-99, respectively. Of these, 48, 43, and 238 proteins were successfully identified, respectively. We propose that the biological effects of low-concentration PBDE-99 exposure are fundamentally different than effects of high-concentration exposure. Low-dose PBDE-99 exposure induced marked effects on cytoskeletal proteins, which was not correlated to cytotoxicity or major morphological effects, suggesting that other more regulatory aspects of cytoskeletal functions may be affected. Interestingly, 0.3 and 3 microM, but not 10 or 30 microM increased the expression of phosphorylated (active) Gap43, perhaps reflecting effects on neurite extension processes.
Alm
Henrik
H
Department of Pharmaceutical Biosciences, Division of Toxicology, Uppsala University, Sweden. Henrik.Alm@farmbio.uu.se
Scholz
Birger
B
Kultima
Kim
K
Nilsson
Anna
A
Andrén
Per E
PE
Savitski
Mikhail M
MM
Bergman
Ake
A
Stigson
Michael
M
Fex-Svenningsen
Asa
A
Dencker
Lennart
L
D000818:Animals; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D016000:Cluster Analysis; D004305:Dose-Response Relationship, Drug; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D005333:Fetus / Q000166:cytology; D005411:Flame Retardants / Q000633:toxicity*; D019922:GAP-43 Protein / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling / Q000379:methods; D018507:Gene Expression Regulation, Developmental; D055768:Halogenated Diphenyl Ethers / Q000633:toxicity*; D009419:Nerve Tissue Proteins / Q000096:biosynthesis*; D020411:Oligonucleotide Array Sequence Analysis; D025341:Principal Component Analysis; D014176:Protein Biosynthesis / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D021241:Spectrometry, Mass, Electrospray Ionization
D005411:Flame Retardants; D019922:GAP-43 Protein; D055768:Halogenated Diphenyl Ethers; D009419:Nerve Tissue Proteins; C086401:pentabromodiphenyl ether