Table 2.
Summary of the NMR and MS results. Metabolites in plasma important for separation of the PD, MSA and PSP patient groups from the control group, and from each other, were identified in the multivariate statistical models generated from the NMR and the MS data. Increased and decreased concentrations of the metabolites are indicated with an upward or downward arrow, respectively. Bold arrows indicate metabolites with a p-value below 0.05 in the univariate analysis. A selection of affected pathways and/or associated physiological functions for each metabolite is listed.
| Metabolite | PD | MSA | PSP | PD | PD | MSA | Pathway or Physiological Function |
|---|---|---|---|---|---|---|---|
| vs. Control | MSA | vs. PSP | PSP | ||||
| Formic acid | 🡇 | 🡇 | 🡇 | 🡅 | 🡅 | 🡅 | Pyruvate met. Methane met., Kynurenine pathway |
| Succinate | 🡅 | 🡅 | 🡅 | Citric acid cycle | |||
| Carnitine | 🡅 | 🡅 | 🡇 | 🡇 | Carnitine biosynthesis, Mitochondrial shuttle system | ||
| L-ArginineNMR | 🡅 | 🡅 | 🡇 | Arg and Pro metabolism, linked to oxidative stress | |||
| L-LysineNMR | 🡇 | 🡇 | Carnitine biosynthesis, Lys synthesis/degradation | ||||
| lysoPC a C26:0 | 🡇 | Lipid metabolism | |||||
| lysoPC a C28:1 | 🡇 | Lipid metabolism | |||||
| TaurineNMR | 🡇 | 🡇 | 🡅 | 🡅 | Neurotransmitter, Neuroprotective | ||
| Lactic acid | 🡅 | Anaerobic glucose and pyruvate metabolism | |||||
| PC ae C44:5 | 🡅 | 🡅 | Lipid metabolism | ||||
| PC ae C42:4 | 🡅 | Lipid metabolism | |||||
| TMAO | ↑ | Methane metabolism | |||||
| Sarcosine | 🡇 | 🡅 | 🡅 | Arg/Pro metabolism, Gly/Ser/Thr metabolism | |||
| Dimethylamine | 🡇 | 🡅 | ↑ | Methane metabolism. Link to oxidative stress regulation | |||
| Pyruvic acid | 🡅 | Energy source for citric acid cycle | |||||
| Acetylcarnitine | 🡅 | 🡇 | MCH FA shuttle system, Glu/Gln/GABA synthesis | ||||
| GlycineMS | 🡇 | ↑ | GSH metabolism | ||||
| Acetoacetate | ↑ | ↓ | Ketone body, propanoate and Leu metabolism | ||||
| 2-HB | 🡅 | Lipid oxidation, oxidative stress | |||||
| 3-HB | ↑ | Ketone body metabolism | |||||
| 3-HIB | ↑ | Linked to brain metabolism and neurotransmission | |||||
| CreatinineMS | 🡅 | Creatine phosphate metabolism | |||||
| GlutamateMS | 🡅 | Glu/Gln/GABA synthesis, Arg synthesis, GSH met. | |||||
| L-GlutamineNMR | ↓ | Glu/Gln/GABA synthesis, Arg synthesis | |||||
| L-HistidineNMR | 🡅 | ↑ | Link to neurotransmission and oxidative stress | ||||
| L-HistidineMS | 🡅 | Link to neurotransmission and oxidative stress | |||||
| L-ValineMS | 🡅 | BCAA synthesis, neurotransmitter synthesis | |||||
| lysoPC a C28:0 | 🡇 | Lipid metabolism | |||||
| Glucose | ↓ | Glucose metabolism |
Abbreviations: met.: metabolism; lysoPC: lysophosphatidylcholine; PC: phosphatidylcholine ; NMR: based on NMR-data; MS: based on MS-data; TMAO: trimethylamine N-oxide; HB: hydroxybuturate; HIB: hydroxyisobutyrate; MCH: mitochondria; FA: fatty acid; GABA: gamma-aminobutyric acid; GSH: glutathione; BCAA: branched chain amino acids.