Teunissen Charlotte E, Markerink-van Ittersum Marjanne, de Bruijn Chris, Steinbusch Harry W M, de Vente Jan
European Graduate School of Neuroscience (Euron), Universiteit Maastricht, Department of Psychiatry and Neuropsychology, P.O. Box 616, 6200 MD, Maastricht, The Netherlands.
Brain Res. 2002 Mar 22;931(1):5-20. doi: 10.1016/s0006-8993(01)03331-5.
The present study investigated whether 3-nitrotyrosine is an early marker for neurodegenerative processes involving oxidative stress. We characterized the 3-nitrotyrosine formation after 3-nitropropionic acid (3-NP) exposure in the whole brain spheroid culture model and in a rat model, using Lewis and Wistar rats. Increased 3-nitrotyrosine concentration in spheroid cultures from Lewis rats was observed at lower dose of and shorter exposure time to 3-NP as compared to alterations in glial fibrillary acidic protein concentration, decrease in glutamine synthetase activity or cell loss. Five days of exposure to 3-NP (5 mM) resulted in decreased staining of GABAergic processes, while neuronal nitric oxide synthase staining was preserved. In addition, staining of EAAC1, anti-2',3'-cyclic nucleotide 3'-phosphohydrolase and ED1 was diminished after treatment of spheroid cultures with 3-nitropropionic acid (5 mM), while isolectin B4 staining was increased. Dithiothreitol and vitamin E inhibited the increased formation of 3-nitrotyrosine. Interestingly, N(G)-nitro-L-arginine methyl ester increased the 3-nitrotyrosine formation. No increased 3-nitrotyrosine concentration was shown after exposure to 3-nitropropionic acid during 5 days in spheroid cultures obtained from Wistar rats. In the striatum of 3-NP-exposed Lewis and Wistar rats, no change in 3-nitrotyrosine concentration was observed, whereas only in Wistar rats the glial fibrillary acidic protein concentration was increased in addition to activation of microglial cells. It is concluded that 3-nitrotyrosine was a more sensitive marker for oxidative stress-induced neurodegeneration than glial fibrillary acidic protein and glutamine synthase in spheroid cell cultures of Lewis rats. Finally, the similarities between the 3-NP spheroid model and the vivo model indicate that the spheroid cultures provide a good alternative for chronic exposure of animals to neurotoxins.
