EVALUATION OF METABOLITES PROFILES CHANGES IN SIM-A9 MICROGLIAL CELLS UNDER THE INFLUENCE OF HYPOXIA AND LIPOPOLYSACCHARIDE

Abstract Microglial cells play a leading role in the development of neuroinflammation. Activation of microglia leads to the formation of reactive phenotypes that can both contribute to the development of neuroinflammation and ensure its resolution. Microglia activation is accompanied by metabolic reprogramming or changes in the metabolic pathways activity and the content of specific metabolites supporting a particular phenotype. The possibility of phenotype switching due to metabolomic reprogramming may have undoubted therapeutic potential. However, currently there is limited data on changes in the composition of metabolites and the activity of metabolic pathways in microglial cells under the influence of neuroinflammatory factors. In this regard, the purpose of this work was to conduct a non-targeted metabolomic study to assess changes of metabolites profiles in microglial cell line SIM-A9 exposed to hypoxia, as well as during TLR4 activation. Metabolite profiling of cell extracts exposed to hypoxia or lipopolysaccharide was performed using high-performance liquid chromatography and high-resolution mass spectrometry, followed by bioinformatics analysis of the data. The results of the conducted studies indicate that hypoxia, as well as TLR4 stimulation, lead to noticeable changes in the metabolism of microglial cells. At the same time, the nature of these changes depends on the type of stress exposure and its duration. Changes in the activity of glutathione and arginine metabolism pathways can serve as a marker of the polarization of microglial cells after hypoxic exposure. The activation of TLR4 by lipopolysaccharide leads to the modulation of pathways associated with energy metabolism, as well as changes in the metabolic pathways of aromatic amino acids. It can be concluded that the approach used in this work will allow us to further investigate the dynamics of metabolic changes under the influence of proinflammatory factors of various nature and to detail their role in the metabolic reprogramming of microglial cells at various stages of neuroinflammation.