A cell line with decreased sensitivity to the methyl mercury-induced stimulation of alpha-amanitin sensitive RNA synthesis in isolated nuclei

Role of Docosahexaenoic Acid in Modulating Methylmercury-Induced Neurotoxicity

The effect of docosahexaenoic acid (DHA) in modulating methylmercury (MeHg)-induced neurotoxicity was investigated in C6-glial and B35-neuronal cell lines. Gas chromatography measurements indicated increased DHA content in both the cell lines after 24 h supplementation. Mitochondrial activity evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5 diphenyltetrazolium bromide (MTT) reduction indicated that 10 microM MeHg treatment for 50 min led to a significant (p < 0.001) and similar decrease in MTT activity in both the cell lines. However, DHA pretreatment led to more pronounced depletion (p < 0.05) in the MTT activity in C6 cells as compared to B35 cells. The depletion of glutathione (GSH) content measured with the fluorescent indicator monochlorobimane was more apparent (p < 0.001) in C6 cells treated with DHA and MeHg. The amount of reactive oxygen species (ROS) detected with the fluorescent indicator -- chloromethyl derivative of dichloro dihydro fluorescein diacetate (CMH(2)DCFDA) -- indicated a fourfold increase in C6 cells (p < 0.001) as compared to twofold increase in B35 cells (p < 0.001) upon DHA and MeHg exposure. However, the cell-associated MeHg measurement using (14)C-labeled MeHg indicated a decrease (p < 0.05) in MeHg accumulation upon DHA exposure in both the cell lines. These findings provide experimental evidence that although pretreatment with DHA reduces cell-associated MeHg, it causes an increased ROS (p < 0.001) and GSH depletion (p < 0.05) in C6 cells.

B35 neuroblastoma cells: an easily transfected, cultured cell model of central nervous system neurons

A panel of neuronal cell lines was derived from tumors of the neonatal rat central nervous system (CNS) in 1974, and two of these lines are in wide use today. Both the B35 and B50 lines offer a number of advantages to researchers who study CNS neurons in culture: they are simple to grow, to differentiate, and to transfect. B50 cells have been used extensively in the study of neuronal cell death, toxicology, and differentiation, whereas B35 cells have proven useful in the molecular analysis of endocytosis and of signaling pathways, in particular those that guide axonal outgrowth and cell motility. This chapter provides protocols for growing and transfecting B35 cells, selecting stable transfectants, exploring protein function using an antisense approach, and assaying cell motility in a Transwell chamber. All of these protocols have been written for researchers who have some skill in basic cell culture techniques, but previous experience with cultured neurons is not required.