Benzo[a]pyrene impairs neurodifferentiation in PC12 cells.

Area of Science:

• Neuroscience
• Toxicology
• Developmental Biology

Background:

• Prenatal exposure to environmental toxicants like benzo[a]pyrene (BaP) is linked to neurobehavioral anomalies in animal models.
• The direct impact of BaP on neuronal development requires further investigation.

Purpose of the Study:

• To investigate the direct effects of benzo[a]pyrene (BaP) on neurodevelopment.
• To compare BaP's effects with chlorpyrifos (CPF), an organophosphate insecticide, using neuronotypic PC12 cells.

Main Methods:

• Assessed cell replication, cell number, neurite outgrowth, and phenotypic differentiation in PC12 cells exposed to BaP and CPF.
• Measured neurotransmitter markers (tyrosine hydroxylase and choline acetyltransferase) to evaluate neurodifferentiation.
• Utilized undifferentiated and nerve growth factor-induced differentiating PC12 cell models.

Main Results:

• Unlike CPF, BaP did not inhibit DNA synthesis in undifferentiated cells.
• BaP increased cell numbers during differentiation, suggesting a delay in cell cycle exit, while CPF decreased them.
• BaP decreased cell enlargement and neurite outgrowth indices, contrasting with CPF's effects.
• BaP significantly reduced both dopamine and acetylcholine phenotype markers, with a greater impact on the acetylcholine phenotype.

Conclusions:

• Low, non-toxic levels of BaP directly impair neurodifferentiation in developing neuronal cells.
• BaP's disruption of neurotransmitter phenotype emergence and promotion of excess cell numbers contribute to adverse neurodevelopmental outcomes.
• These findings highlight BaP's direct neurotoxic potential during critical developmental windows.