Abstract: PO1419
Alterations in Amino Acid and Lipid Metabolism in ANCA-Stimulated Monocytes
Session Information
- Glomerular Diseases: Immunology and Inflammation in Vasculitis and Lupus Nephritis
November 04, 2021 | Location: On-Demand, Virtual Only
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1202 Glomerular Diseases: Immunology and Inflammation
Authors
- Leacy, Emma, Trinity Translational Medicine Institute, Dublin, Ireland
- Khouri, Hania, Agilent Technologies UK Ltd, Cheadle, United Kingdom
- Brady, Gareth, Trinity Translational Medicine Institute, Dublin, Ireland
- Little, Mark Alan, Trinity Translational Medicine Institute, Dublin, Ireland
Background
Multiple metabolic pathways and intermediates are involved in inflammation. Altered immune cell metabolism is involved in the pathogenesis of autoimmune diseases such as anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). In particular, monocytes stimulated with ANCA show increased oxidative phosphorylation and glycolysis, with a more profound response to myeloperoxidase (MPO) ANCA than proteinase-3 (PR3). The aim of this work was to profile the metabolome of ANCA-stimulated primary monocytes.
Methods
Monocytes from healthy donors (n=24) were isolated and stimulated with monoclonal anti-MPO, anti-PR3 for 4 hours. Metabolites were extracted using an optimised extraction protocol and analysed by liquid chromatography–mass spectrometry (LC–MS). Targeted and untargeted analyses were carried out using Agilent MassHunter Profinder and Mass Profiler Professional. Cytokine production was measured by ELISA and flow cytometry was used to assess surface expression of MPO and PR3.
Results
Targeted metabolomic analysis showed increases in several amino acid and TCA cycle metabolites relative to unstimulated cells, notably phenylalanine, isomers leucine & isoleucine, and fumarate. Untargeted analysis confirmed alterations in amino acid and lipid metabolism in ANCA-stimulated monocytes (Figure 1). These metabolic differences did not correlate with the increased cytokine expression observed in anti-MPO-treated monocytes. Anti-PR3 stimulation did not induce major changes in metabolism or cytokine production. Monocytes expressed high levels of surface MPO and PR3, with MPO expression showing a significant inverse correlation with age.
Conclusion
Inflammatory and metabolomic activation of primary human monocytes occurs with anti-MPO, but not anti-PR3 stimulation. Early increases in amino acid and lipid metabolism are evident in anti-MPO treated cells. Further work is needed to validate these findings and determine their physiological relevance in AAV.
Funding
- Commercial Support –