3-methylcholanthrene induces neurotoxicity in developing neurons derived from human CD34+Thy1+ stem cells by activation of aryl hydrocarbon receptor.

Developing neurons, derived from the human umbilical cord blood stem cells (hUCBSCs), were investigated for their stage-specific responses against 3-methylcholanthrene (MC), a well-known polycyclic aromatic hydrocarbon. Three-dimensional (3D) molecular docking demonstrates the strong hydrogen bonding and hydrophobic interactions of MC with amino acids of aryl hydrocarbon receptor (AHR) and aryl hydrocarbon receptor nuclear translocator (ARNT) within 4 Å and subsequent inhibition of cAMP response element-binding protein (CREB), α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptors. Protein-protein docking also confirms that induced levels of AHR inhibit the neurogenesis-related transcription factor (CREB) with maximum docking scores. In concurrence with in silico data, MC exposure significantly up regulates the expression and activity of AHR, CYP1A1 and glutathione S-transferase P1-1 (GSTP1-1) and down regulates the expression of CREB, AMPA and NMDA receptors in hUCBSC-derived neuronal cells at various maturity (0, 2, 4, 8 days of differentiation). MC-mediated significant down regulation in the expression of stage-specific neuronal markers (Nestin, neural cell adhesion molecule-NCAM, synaptophysin-SYP, CREB, AMPA and N-methyl-D-aspartate receptor subunit 2A-NR2A) was also noticed in cells all through the differentiation. Data identify the possible interference of MC in neuronal transmission and neurogenesis.