ИСТИНА

Objective Copper is a trace element involved in many physiological processes, and the balance of Cu2+ is crucial for brain cell functioning. The disruption of copper homeostasis induces the damage of brain cells and the development of pathological processes. It is important to know how Cu2+ can affect brain astrocytes, since these cells are involved in Cu2+ metabolism, so we investigated the effect of Cu2+ on dissociated cultured astrocytes from rat cerebral cortex. Methods Cells were incubated with 25-200 µM of CuCl2 for 24 hours. Cell viability was analyzed using MTT-test. Astrocytes were identified with antibodies against vimentin, GFAP and glutamine synthetase. The functional state of mitochondria was assessed using JC-1 and MitoTracker Green FM. The ultrastructure of cells was visualized with transmission electron microscopy. Result CuCl2 caused dose-dependent decrease in astrocytes viability rate: 87% at 50 µM, 82% at 100 µM and 66% at 200 µM. Ultimately, 100 µM CuCl2 was used for further experiments. This concentration of Cu2+ induced the damage and shrinkage of GFAP-positive cells. The same effect was detected among subpopulations of glutamine synthetase-positive or vimentin-positive cells. Cu2+ ions also caused a decrease in mitochondrial membrane potential and disruption of the ultrastructure of mitochondria. Conclusion Cu2+ cause a dose-dependent decrease of astrocyte viability, and one of the main targets Cu-induced damage are mitochondria.