Transport of tryptophan into SH-SY5Y neuronal cells

Abstract

The human neuroblastoma cell line SH-SY5Y is a commonly used catecholaminergic model in studies related to neurotoxicity of various substances, oxidative stress, and neurodegenerative diseases. Specific transport of monoamine neurotransmitter precursors i.e. corresponding aromatic amino acids, into these cells is essential for cellular metabolism. Serotonin (5-hydroxytryptamine) is a neurotransmitter synthesized in the brain that is implicated in many brain disorders including Schizophrenia and manic depression. Serotonin is synthesized from tryptophan in serotonergic neurons. In the present study we have examined the uptake of L-tryptophan into SH-SY5Y cells by reverse phase high performance liquid chromatography coupled with UV detection. This study shows that SH-SY5Y cells possess significant capacity to take up extracellular tryptophan. The tryptophan uptake was inhibited by a specific inhibitor of system L, a transport system present in mammalian cells serves for neutral amino acids, providing evidence that tryptophan enters the cells via transport system L. Both undifferentiated and 12-O-tetradecanoly-phorbol-12-acetate (TPA) differentiated SH-SY5Y cells show similar tryptophan uptake efficiencies.