Study of the chlorpyrifos neurotoxicity using neural differentiation of adipose tissue‐derived stem cells

Abstract

Chlorpyrifos (CPF) is the most commonly used organophosphorus insecticide which causes neurodevelopmental toxicity. So far, animals have been used as ideal models for neurotoxicity studies, but working with animals is very expensive, laborious, and ethically challenging. This has encouraged researchers to seek alternatives. During recent years, several studies have reported successful differentiation of embryonic and adult stem cells to neurons. This has provided an excellent model for neurotoxicologic studies. In this study, neural differentiation of mouse adipose tissue-derived stem cells (ADSCs) was used as an in vitro model for investigation of CPF neurotoxicity. For this purpose, mouse ADSCs were cultured in a medium containing knockout serum replacement and were treated with different concentrations of CPF at several stages of differentiation. Cytotoxic effect of CPF and the expression of neuron-specific genes and proteins were studied in the differentiating ADSCs. Furthermore, the activity of acetylcholinesterase was assessed by Ellman assay at different stages of differentiation. This study showed that up to 500 μM CPF did not alter viability of the undifferentiated ADSCs, whereas viability of the differentiating cells decreased with 500 μM CPF. CPF upregulated the expression of some neuron-specific genes and seemed to decrease the number of β-tubulin III and MAP2 proteins-expressing cells. There was no detectable acetylcholine esterase activity in differentiated ADSCs. In summary, it was shown that CPF treatment can decrease the viability of ADSC-derived neurons and dysregulate the expression of some neuronal markers through acetylcholinesterase-independent mechanisms. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1510-1519, 2016.

Comparison of the neuronal differentiation abilities of bone marrow-derived and adipose tissue-derived mesenchymal stem cells

“…BMSCs and ADSCs are known to differentiate into neurons ( 22 , 23 ). In our study, nestin, a neural precursor stem cells marker, and β-tubulin III, an immature neuronal marker, were expressed in native BMSCs and ADSCs, which suggested that both MSCs retained a native potential for neuronal differentiation and were in conformity with other studies ( 20 ).…”

Knockdown of Butyrylcholinesterase but Not Inhibition by Chlorpyrifos Alters Early Differentiation Mechanisms in Human Neural Stem Cells

“…Neither study quantified the cholinesterase activity. Another study used adipose-derived stem cells to model CPF toxicity [ 43 ] but used a much higher dose of CPF (500 μM), finding decreased viability in differentiating cells. One study examined differentiation outcomes in embryonic stem cell-derived NPCs, finding reduced proportions of glial cells upon exposure to 10–30 μM CPF [ 44 ].…”

Knockdown of butyrylcholinesterase but not inhibition by chlorpyrifos alters early differentiation mechanisms in human neural stem cells

“…Neither study quantified cholinesterase activity. Another study used adiposederived stem cells to model CPF toxicity [44], but used a much higher dose of CPF (500 μM),…”

“…Others used neuron-like cell lines including N2a and PC12 cells, identifying cellular effects such as neurite retraction [46,47], which would reflect events much later than the initial NSC differentiation modeled here. Our goal was to identify specific mechanisms affected early in NSC differentiation, since these events are likely to cause changes in differentiation choice, such as the reduced glial differentiation [44], or changes in neuronal circuitry due to shifted differentiation patterns.…”