Rapid and High-Throughput Detection and Quantitation of Radiation Biomarkers in Human and Nonhuman Primates by Differential Mobility Spectrometry-Mass Spectrometry

Abstract

Abstract. Radiation exposure is an important public health issue due to a range of accidental and intentional threats. Prompt and effective large-scale screening and appropriate use of medical countermeasures (MCM) to mitigate radiation injury requires rapid methods for determining the radiation dose. In a number of studies, metabolomics has identified small-molecule biomarkers responding to the radiation dose. Differential mobility spectrometry-mass spectrometry (DMS-MS) has been used for similar compounds for high-throughput small-molecule detection and quantitation. In this study, we show that DMS-MS can detect and quantify two radiation biomarkers, trimethyl-L-lysine (TML) and hypoxanthine. Hypoxanthine is a human and nonhuman primate (NHP) radiation biomarker and metabolic intermediate, whereas TML is a radiation biomarker in humans but not in NHP, which is involved in carnitine synthesis. They have been analyzed by DMS-MS from urine samples after a simple strong cation exchange-solid phase extraction (SCX-SPE). The dramatic suppression of background and chemical noise provided by DMS-MS results in an approximately 10-fold reduction in time, including sample pretreatment time, compared with liquid chromatography-mass spectrometry (LC-MS). DMS-MS quantitation accuracy has been verified by validation testing for each biomarker. Human samples are not yet available, but for hypoxanthine, selected NHP urine samples (pre-and 7-d-post 10 Gy exposure) were analyzed, resulting in a mean change in concentration essentially identical to that obtained by LC-MS (fold-change 2.76 versus 2.59). These results confirm the potential of DMS-MS for field or clinical first-level rapid screening for radiation exposure.

Metabolomic applications in radiation biodosimetry: exploring radiation effects through small molecules

“…Efforts in deployable devices have already identified technologies that can be sized down to a more compact instrumentation, unlike the ones currently utilized in the discovery and quantification phases. In particular, technologies like differential mobility spectrometry- mass spectrometry (DMS-MS) has shown encouraging results in the selectivity, speed, and accurate quantification of previously identified biomarkers (Coy et al, 2010, Coy et al, 2011, Coy et al., 2013, Chen et al, 2016), and will be explored more in detail in the future. Finally, it is encouraging that radiation metabolomics has not only provided answers on the molecular level, but it can be utilized successfully for assessment of radiation exposure, suggestion of appropriate medical triage, and potentially risk assessment.…”

“…Mice injected with 137 CsCl 2 show distinctly different metabolic profiles from control mice (Goudarzi et al, 2014b) at 2 days (1.95 Gy), 5 days (4.14 Gy), 20 days (9.46 Gy), and 30 days (9.91 Gy) post injection. While some markers were previously identified with either high or low dose rate external beam irradiation (xanthurenic acid, taurine, uric acid, citrate, alpha-ketoglutaric acid, hippuric acid, tiglylcarnitine, hexanoylcarnitine,) (Tyburski et al, 2008, Tyburski et al, 2009, Laiakis et al, 2012, Goudarzi et al, 2014a, Chen et al, 2016) and therefore do not reflect a specific internal emitter signature, others such as tiglylglycine, isoleucine/leucine, isovalerylglycine, and isethionic acid were specific for 137 Cs. Urinary analysis from mice exposed to 85/90 SrCl 2 , which is known to deliver most of the dose to the skeleton and bone marrow, also validated low dose rate markers (xanthurenic acid, riboflavin, tiglylcarnitine, hexanoylcarnitine, and retinoic acid) (Goudarzi et al, 2015c).…”

Application of liquid chromatography-mass spectrometry and differential mobility spectrometry-mass spectrometry for detection and quantitation of biomarkers in complex biological matrices

“…Because of its very high concentration in human and NHP urine, creatinine could be quantified by direct dilution, since high dilution reduces matrix effects effectively [90][91][92][93]. The creatinine calibration curve was generated using a 2500-fold dilution in solvent (50% ACN + 0.1% formic acid) with IS addition.…”

“…In recent years, DMS-MS has emerged as a rapid gas phase separation technology which has been used for many applications such as drug metabolites [90] and radiation biomarkers [91]. As opposed to LC-MS which separates compounds in minutes and even longer, the separation time for DMS-MS is only milliseconds which is well suited for rapid and high-throughput detection and quantitation.…”

“…The most noticeable advantages of this platform are the background removal by DMS as shown in Figure 33 and much faster analysis time. DMS-MS typically has a separation time in the order of milliseconds compared to minutes in LC-MS and 15-to 30-fold higher throughput than the latter approach [91]. …”