Changes in the NMR metabolic profile of human microglial cells exposed to lipopolysaccharide or morphine
Issam El Ghazi1, Wen S Sheng, Shuxian Hu
1Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
Abstract:
Microglial cells play a major role in host defense of the central nervous system. Once activated, several functional properties are up-regulated including migration, phagocytosis, and secretion of inflammatory mediators such as cytokines and chemokines. Little, if anything, is known about the metabolic changes that occur during the activation process. High-resolution (1)H nuclear magnetic resonance spectra obtained from perchloric acid extracts of human microglial cell cultures exposed to lipopolysaccharide (LPS) or morphine were used to both identify and quantify the metabolites. We found that human microglia exposed to LPS had increased concentrations of glutamate and lactate, whereas the cells exposed to morphine had decreased concentrations in creatinine, taurine, and thymine. Glutamate and creatinine were the key metabolites differentiating between the two stimuli. These results are discussed in terms of activation and differences in the inflammatory response of human microglial cells to LPS and morphine.
Insights
This study reveals metabolic shifts in human microglial cells upon activation. Lipopolysaccharide (LPS) increased glutamate and lactate, while morphine decreased creatinine, taurine, and thymine, highlighting distinct metabolic responses.
Area of Science:
- Neuroscience
- Immunology
- Metabolomics
Background:
- Microglial cells are crucial for central nervous system defense.
- Activation up-regulates functions like migration and cytokine secretion.
- Metabolic changes during microglial activation are largely unknown.
Purpose of the Study:
- To investigate metabolic alterations in human microglial cells during activation.
- To compare metabolic profiles following stimulation with lipopolysaccharide (LPS) and morphine.
Main Methods:
- Human microglial cell cultures were stimulated with LPS or morphine.
- High-resolution (1)H nuclear magnetic resonance spectroscopy was used.
- Metabolites were identified and quantified from perchloric acid extracts.
Main Results:
- LPS stimulation increased glutamate and lactate concentrations.
- Morphine exposure decreased creatinine, taurine, and thymine concentrations.
- Glutamate and creatinine levels effectively differentiated between LPS and morphine stimuli.
Conclusions:
- Microglial activation involves significant metabolic reprogramming.
- Distinct stimuli elicit unique metabolic fingerprints in microglial cells.
- These findings offer insights into differential inflammatory responses.
