Copper regulates the expression of immune genes in microglial cells in vitro

Copper, a transition metal, plays crucial roles in various physiological functions, including those of the nervous and immune systems. Dysregulation of copper homeostasis is linked to several diseases, such as neurodegenerative diseases. Since dysfunctional microglial immunity can also contribute to such diseases, we investigated the role of copper in microglial immunity. Currently, the roles of copper in microglial immunity are considered complex and multifaceted, with both anti- and pro-inflammatory effects having been proposed. In the current study, we found that both increased and decreased copper levels suppressed lipopolysaccharide (LPS)-mediated inflammation in microglial cells, as determined by RT-qPCR analysis. RNA sequencing (RNA-seq) analysis confirmed that increased copper levels reduced the inflammatory response to LPS; however, it also showed that decreased copper levels affected genes involved in cell proliferation, transcription, and autophagosome regulation. These findings suggest that copper is vital for maintaining normal immune functions in microglia, and that both copper excess and deficiency can disrupt microglial immunity.