Fipronil interferes with the differentiation of mouse N2a neuroblastoma cells
Erasmia Sidiropoulou1, Magdalini Sachana, John Flaskos
1Department of Infection Biology, Institute of Infection & Global Health, University of Liverpool, Leahurst Campus, Leahurst, Neston, Wirral CH64 7TE, UK.
Abstract:
The purpose of this study was to evaluate the neurotoxic potential of the pesticide fipronil (FIP) towards the differentiation of mouse N2a neuroblastoma cells. At concentrations of 1, 5 and 10 μM that were not cytotoxic, as shown by two different cell viability assays, FIP impaired potently after 24h the development of axon-like processes, with a concentration of 1 μM causing 50% inhibition. Densitometric analysis of immunoblots of extracts of N2a cells exposed to FIP demonstrated that the axon-inhibitory action of the pesticide was not accompanied by significant changes in the levels of total and phosphorylated neurofilament heavy chain (NFH). FIP also induced no alteration in the levels of total and tyrosinated α-tubulin. On the other hand, this pesticide caused severe disruption of the developmentally important ERK 1/2-MAP kinase signal transduction pathway, as evidenced by significant reductions in the activation state of MAPK kinase (MEK 1/2) and, particularly, ERK 1/2. The above data seem to justify very recent concerns that FIP has the capacity to induce developmental neurotoxicity in mammals.
Insights
The pesticide fipronil (FIP) impairs mouse neuroblastoma cell development by inhibiting axon growth. FIP disrupts the ERK1/2-MAP kinase pathway, suggesting potential developmental neurotoxicity in mammals.
Area of Science:
- Neuroscience
- Toxicology
- Cell Biology
Background:
- Pesticide exposure is a growing concern for neurological health.
- Fipronil (FIP) is a widely used insecticide with potential neurotoxic effects.
- Understanding FIP's impact on neuronal development is crucial.
Purpose of the Study:
- To investigate the neurotoxic potential of fipronil (FIP) on the differentiation of mouse N2a neuroblastoma cells.
- To determine the effects of non-cytotoxic FIP concentrations on neuronal process development.
- To elucidate the molecular mechanisms underlying FIP-induced neurotoxicity.
Main Methods:
- Mouse N2a neuroblastoma cells were treated with varying concentrations of FIP (1, 5, 10 μM).
- Cell viability was assessed using two different assays to establish non-cytotoxic concentrations.
- Immunoblotting was used to analyze the levels of neurofilament heavy chain (NFH) and α-tubulin.
- The activation state of the ERK1/2-MAP kinase pathway (MEK1/2 and ERK1/2) was evaluated.
Main Results:
- FIP significantly inhibited the development of axon-like processes in N2a cells at non-cytotoxic concentrations.
- A concentration of 1 μM FIP caused 50% inhibition of axon development.
- No significant changes were observed in the levels of total and phosphorylated NFH or total and tyrosinated α-tubulin.
- FIP markedly disrupted the ERK1/2-MAP kinase pathway, reducing the activation of MEK1/2 and ERK1/2.
Conclusions:
- Fipronil exhibits neurotoxic potential by impairing neuronal differentiation and axon development.
- The mechanism of FIP-induced neurotoxicity involves the disruption of the ERK1/2-MAP kinase signaling pathway.
- These findings support recent concerns regarding the capacity of FIP to induce developmental neurotoxicity in mammals.
