Liquid Chromatography–Mass Spectrometry-Based Metabolomics of Nonhuman Primates after 4 Gy Total Body Radiation Exposure: Global Effects and Targeted Panels

Abstract

Rapid assessment of radiation signatures in non-invasive biofluids may aid in assigning proper medical treatments for acute radiation syndrome (ARS) and delegating limited resources after a nuclear disaster. Metabolomic platforms allow for rapid screening of biofluid signatures and show promise in differentiating radiation quality and time postexposure. Here, we use global metabolomics to differentiate temporal effects (1-60 d) found in nonhuman primate (NHP) urine and serum small molecule signatures after a 4 Gy total body irradiation. Random Forests analysis differentially classifies biofluid signatures according to days post 4 Gy exposure. Eight compounds involved in protein metabolism, fatty acid β oxidation, DNA base deamination, and general energy metabolism were identified in each urine and serum sample and validated through tandem MS. The greatest perturbations were seen at 1 d in urine and 1-21 d in serum. Furthermore, we developed a targeted liquid chromatography tandem mass spectrometry (LC-MS/MS) with multiple reaction monitoring (MRM) method to quantify a six compound panel (hypoxanthine, carnitine, acetylcarnitine, proline, taurine, and citrulline) identified in a previous training cohort at 7 d after a 4 Gy exposure. The highest sensitivity and specificity for classifying exposure at 7 d after a 4 Gy exposure included carnitine and acetylcarnitine in urine and taurine, carnitine, and hypoxanthine in serum. Receiver operator characteristic (ROC) curve analysis using *

Serum Metabolomic Alterations Associated with Cesium-137 Internal Emitter Delivered in Various Dose Rates

“…Metabolomics has been used extensively in developing radiation signatures for biodosimetry in biofluids in biological organisms ranging from murine models [ 14 , 15 ], to non-human primates [ 16 , 17 ], and total body irradiated patients [ 18 , 19 ]. Exposure to ionizing radiation induced significant changes of a variety of small molecules in mouse serum, including hypoxanthine, carnitine, proline, taurine, and some lipid mediators of inflammation.…”

Metabolomics in Radiation Biodosimetry: Current Approaches and Advances

“…In addition, 2 -aminobutyric acid, 2 -deoxycytidine, and choline were also identified as potential biomarkers of ionizing radiation [172]. When compared to other studies, a recent NHP study also detected decreased levels of aspartic acid, glycine, and tyrosine, but other levels showed the opposite response [127]. Such findings highlight the importance of understanding the chosen MS technology, as well as the sample type (e.g., blood, plasma, urine, tears, etc.)…”

“…Changes in urine metabolites in response to irradiation have been known for decades, with rodent studies first conducted in the 1980s [122]. A wide variety of metabolic pathways can be impacted by radiation, as seen in the urine, with changes in biomarkers reflecting damage or changes to the microbiome, urea cycle, as well as amino acid, protein, fatty acid, and hormone metabolism across rodents [123,124], NHPs [125][126][127], and humans [22]. Curiously, Laiakis et al found that metabolic markers in mouse urine could distinguish between lipopolysaccharide (LPS)-induced inflammation and radiation-induced inflammation [128], even different types of radiation were distinguishable in these samples [24,36].…”

“…Temporal changes in metabolomic biomarkers can also vary depending on sex [22,118,126,154], as discussed earlier. Additionally, temporal metabolomic changes and diagnostic/prognostic accuracy of metabolomic markers may vary depending on the sample type [127,140], which is also a factor to consider when designing biomarker discovery and validation studies.…”

Urine metabolomics based prediction model approach for radiation exposure

“…Metabolomics is one such high-throughput technology that has great potential for radiation bio-dosimetry that can play an imperative role during the initial triage of radiological disasters to characterize the metabolic status of an individual before the onset of symptoms. It is about a decay old omics technique and in the last few years, its application has been extended towards qualitative and quantitative assessment of ionization radiation exposure induced response mainly in biological fluids, serum and urine [7][8][9][10][11][12][13][14] . Liquid chromatography-mass spectrometry (LC-MS) based studies have elucidated many urinary metabolic markers for radiation exposure pertaining to oxidative stress, energy metabolism, DNA damage, inflammation, and tissue damage 4,15,16 .…”