The effect of copper ions on cultured rat glial cells of the cerebral cortex under the action of lipopolysaccharide.

Copper ions (Cu2+) at concentrations of 25-50 μM stimulate lipopolysaccharide (LPS)-induced nitric oxide (NO) production in glial cell cultures derived from rat cerebral cortex and containing both astrocytes and microglia. Addition of a higher Cu2+ concentration (100 μM) during LPS stimulation did not significantly increase NO in the incubation medium, while 200 μM Cu2+ decreased this parameter compared to LPS. Cu2+ ions at these concentrations decreased viability of cultured cells. Apparently, the decrease in cell viability is not associated with nitrite accumulation, because the addition of even 100 μM sodium nitrite to the culture medium did not reduce cell viability or affect the cytotoxicity of Cu2+. The study of microglial cells (using the IBA1 marker) revealed that in LPS-treated cultures, microglia had a predominantly flattened amoeboid morphology, characteristic of activated microglia. The LPS treatment also increased the cell body profile area and perimeter. At a concentration of 25 μM, Cu2+ ions did not affect the morphological changes in microglia associated with the inflammatory phenotype. It is possible that the copper-induced increase in LPS-induced NO production is mediated by astrocytes.