Stimulation of Neurite Outgrowth in Neuroblastoma Cells by Neuraminidase: Putative Role of GM1 Ganglioside in Differentiation

Abstract

Treatment of three neuroblastoma cell types in culture with neuraminidase resulted in enhanced neurite outgrowth. These included the mouse Neuro-2A and rat B104 and B50 lines. The morphological changes depended on the presence of exogenous Ca²⁺ and were accompanied by modest but statistically significant increases in ⁴⁵Ca²⁺ influx. Neur-aminidase-stimulated neuritogenesis was blocked by the B subunit of cholera toxin (cholera B) and anti-GM1 antibody, a finding suggesting the effect was due to an increased amount of GM1 on the cell surface. Cholera B also blocked the increase in ⁴⁵Ca²⁺ influx. The mouse N1A-103 line, previously characterized as “neurite minus,” did not respond to neuraminidase with either neurite outgrowth or enhanced Ca²⁺ influx. These results point to an influence of GM1 on neuritogenesis in cells with differentiation potential and suggest a mechanism involving modulation of Ca²⁺ flux.