Are SH‐SY5Y and MN9D cell lines truly dopaminergic?

Abstract

SH-SY5Y and MN9D cell lines are commonly used dopaminergic models in studies related to neurotoxicity, oxidative stress, and neurodegenerative disease. Early studies suggested that SH-SY5Y cells do not convert intracellular dopamine (DA) to norepinephrine (NE) even though dopamine-β-monooxygenase is present. Our studies show that these cells do not synthesize or store substantial levels of DA or NE, however extracellular DA is taken up and converted to NE and this efficiency increases with the number of passages. Reversed-phase HPLC-EC kinetic studies show that NE is a better substrate for plasma membrane transporters than DA. Thus, undifferentiated high-passage SH-SY5Y cells could be a good noradrenergic model for in vivo studies. In contrast, 12-O-tetradecanoyl-phorbol-13-acetate differentiated SH-SY5Y cells store substantially higher levels of DA and NE. These cells take up DA and NE more efficiently than undifferentiated cells suggesting they could be used as noradrenergic or dopaminergic models. MN9D cells store high levels of DA under normal conditions, but do not convert DA to NE. They show poor catecholamine uptake characteristics compared to undifferentiated SH-SY5Y cells, however n-butyric acid differentiated MN9D cells show efficient DA uptake kinetics similar to undifferentiated SH-SY5Y, suggesting that they could be used as a reasonable dopaminergic model. Supported by NIH NS 39423.