The Effect of Astrocyte-Conditioned Medium (ACM) and Retinoic Acid on Neural Differentiation of Mouse Embryonic Stem Cells

Purpose: The aim of this research was to study the properties of factors secreted from astrocyte cells in suspension medium in direct differentiation of mouse embryonic stem cells into neural cells. Materials and Methods: Royan B1 mouse embryonic stem (ES) cells were used in this experiment. For differentiation of Es cells into the neural cells, the astrocyte-condition medium (ACM) of mouse fetus hippocampus astrocytes was used. The process that differentiated these cells was based on forming embryoid bodies (EBs). These EBs were treated with retinoic acid (RA), basic fibroblast growth factor (bFGF) and ACM within 4 days (2+4d) under suspension condition in 7 groups. Then differentiation of these EBs was promoted on poly-l-lysine. With the use of immunocytochemistry and RT-PCR methods, the markers indicating the neural and cardiac differentiated cells from ES cells were studied. Results: In this experiment EBs cells were differentiated within 5 days (2+4+5d) into different neural cells including neurons, astrocytes, and cardiac cells. However, The statistical analysis of EBs differentiated percentage showed that under ACM effect, ES cells did not differentiate into neural cells and only their cardiac differentiation rate were decreased. But under RA effect, more than 50% of the Es cells showed 40% nueral differentiation and ES cells under effect of bFGF did not differentiate into cardiac cells. Conclusion: Findings of this study revealed that ACM probably don't play role in direct differentiation of Es cells into neural cells and only decreases differentiation into cardiac cells. RA as a strong inducer also causes differentiation of ES cells into neural cells.