In recent years, the use of stem cells as a new tool to create an in vitro model for toxicological studies has been considered. Adipose tissue-derived stem cells (ADSCs) are mesenchymal stem cells which have been extracted from adipose tissue by a less invasive method and rapidly propagated in culture medium compared with other sources. These cells have the capacity to differentiate into different cell lineage in vitro including neural cells. The aim of this study was to investigate the effect of lead exposure at various stages of differentiation on the neural differentiation of ADSCs. Third-passaged ADSCs were differentiated to neural cell in differentiation medium during 16 d. The ADSCs were exposed to lead (0.1-100 µg/ml) before differentiation and during differentiation on days 1, 7 and 14. The cell viability was assessed by MTT assay after 48 h. Also expression of β-tubulin III protein and Nestin, NeuN, NF70, Synaptophysin genes were evaluated at the end of differentiation in all treated groups. The results showed that lead had no effect on viability of undifferentiated ADSCs but differentiating cells showed various sensitivities to lead exposure and cells were more vulnerable to lead exposure at early stage of differentiation. Also, lead exposure at different stages of differentiation had various effects on gene expressions. Our study indicated that neural cells differentiated from ADSCs in vitro are sensitive to neurotoxic effect of lead as well-known developmental neurotoxicant, and then ADSCs could be a candidate as an alternative method for assessing neurodevelopmental toxicity potential of chemicals.
Keywords: Adult stem cell; alternative method; lead; neurotoxicity.