[Protective effect of gangliosides against the toxic action of bacterial lipopolysaccharide of various serotypes on PC12 cells].

The effect of bacterial lipopolysaccharide (LPS) from E. coli on the viability of PC12 neuronal cell line was studied. LPS of 0111:B4 serotype and LPS of 055:B5 serotype were shown to have toxic effect on PC12 cells.

[Metabolic effects of ganglioside GM1 on PC12 cells at oxidative stress depend on modulation of activity of tyrosine kinase of trk receptor].

Evidence has been obtained that only GM1, but also other main brain gangliosides (GD1a, GD1b, and GT1b) increase viability of ells of the PC12 neuronal line submitted to action of H2O2. By the example of GM1 and GD1a, gangliosides have been shown to induce a protective effect when acting on PC12 cells under conditions of oxidative stress both at micro- and nanomolar concentrations that are physiological concentrations of gangliosides in cerebrospinal fluid. It has been shown for the first time that GM1 at nanomolar concentrations decrease the H2O2-induced formation of reactive oxygen species (ROS).

[Role of tyrosine kinase of Trk-receptors in realization of antioxidant effect of ganglioside GM1 in PC12 cells].

Ganglioside GM1 has been shown to increase viability of PC12 cells at their induction of oxidative stress by hydrogen peroxide. However, in the presence of inhibitor of tyroxine kinase Trk-receptors K-252a this GM1 effect decreases or virtually disappears. To understand mechanism of the protective effect, there was studied action of H2O2, GM1, and inhibitor K-252a on formation of reactive oxygen species (ROS).

[A decrease of neuroprotector effect of ganglioside GM1 on PC12 cells under conditions of oxidative stress in the presence of inhibitor of tyrosine kinase of Trk-receptors].

Effects of inhibitors of tyrosine kinases (K-252a, genistein) and of phospholipase A2 (bromophenacetyl bromide) on viability of PC12 cells are studied in the presence of hydrogen peroxide and ganglioside GM1. The degree of inhibition of hydrogen peroxide cytotoxic effect by ganglioside GM1 amounted to 52.8 +/- 4.

[PC12 cells transfected with human mutant gene causing one of Alzheimer's disease forms have a high sensitivity to oxidative stress].

Used in this work are PC12 cells transfected with human gene expressing amyloid precursor protein of beta-peptide and carrying the so-called "Swedish mutation" leading to the appearance of one Alzheimer's disease family forms. It has been shown that the PC12 cells transfected with this mutant gene, at action of various hydrogen peroxide concentrations, die to the significant greater degree than the used for comparison PC12 cells transfected with analogous human gene of the wild type or than vector-transfected cells. It has been found that ganglioside GM1 at micro- or nanomolar concentrations is able to increase viability of the PC12 cells transfected with the mutant gene causing a significant accumulation of endogenous amyloid beta-peptide.