An NMR metabolomic investigation of early metabolic disturbances following traumatic brain injury in a mammalian model

Abstract

The effects of traumatic brain injury (TBI) on brain chemistry and metabolism were examined in three groups of rats using high-resolution (1)H NMR metabolomics of brain tissue extracts and plasma. Brain injury in the TBI group (n = 6) was produced by lateral fluid percussion and regional changes in brain metabolites were analyzed at 1 h after injury in hippocampus, cortex and plasma and compared with changes in both a sham-surgery control group (n = 6) and an untreated control group (n = 6). Evidence was found of oxidative stress (e.g. decreases in ascorbate of 16.4% (p<0.01) and 29.7% (p<0.05) in cortex and hippocampus, respectively) in TBI rats versus the untreated control group, as well as excitotoxic damage (e.g. decreases in glutamate of 14.7% (p<0.05) and 12.3% (p<0.01) in the cortex and hippocampus, respectively), membrane disruption (e.g. decreases in the total level of phosphocholine and glycerophosphocholine of 23.0% (p<0.01) and 19.0% (p<0.01) in the cortex and hippocampus, respectively) and neuronal injury (e.g. decreases in N-acetylaspartate of 15.3% (p<0.01) and 9.7% (p>0.05) in the cortex and hippocampus, respectively). Significant changes in the overall pattern of NMR-observable metabolites using principal components analysis were also observed in TBI animals. Although TBI clearly had an effect on the metabolic profile found in brain tissue, no clear effects could be discerned in plasma samples. This was at least partly due to large variability in dominant glucose and lactate peaks in plasma. However, disruption of the blood-brain barrier and the subsequent movement of metabolites from brain into blood may have been relatively small and below the detection limits of our analytical procedures. Overall, these data indicate that TBI results in several significant changes in brain metabolism early after trauma and that a metabolomic approach based on (1)H NMR spectroscopy can provide a metabolic profile comprising several metabolite classes and allow for relative quantification of such changes within specific brain regions. The results also provide support for further development and application of metabolomic technologies for studying TBI and for the utilization of multivariate models for classifying the extent of trauma within an individual.

A simple and accurate protocol for absolute polar metabolite quantification in cell cultures using quantitative nuclear magnetic resonance

“…Interest in quantitative nuclear magnetic resonance (q-NMR) analysis has steadily increased since the seminal works of Jungnickel and Forbes [1] and Hollis [2], owing to the unique ability of this methodological approach to quantify, at the same time, a wide range of structurally diverse biological substances with high throughput and automation [3]. Compared with other analytical techniques, q-NMR does not require chromatographic separation, generates signals that are directly proportional to the number of NMR-active nuclei in the targeted analyte [4,5], and offers a high degree of assay reproducibility [6] along with reduced uncertainty [7,8].…”

“…We identified and quantified (i) metabolic differences between genetically engineered human cell lines, (ii) alterations in cellular metabolism induced by differentiation of mouse myoblasts into myotubes, and (iii) metabolic changes caused by activation of neurotransmitter receptors in mouse myoblasts. Thus, the new protocol offers an easily implementable, efficient, and versatile tool for the investigation of cellular metabolism and signal transduction.© 2016 Elsevier Inc. All rights reserved.Interest in quantitative nuclear magnetic resonance (q-NMR) analysis has steadily increased since the seminal works of Jungnickel and Forbes [1] and Hollis [2], owing to the unique ability of this methodological approach to quantify, at the same time, a wide range of structurally diverse biological substances with high throughput and automation [3]. Compared with other analytical techniques, q-NMR does not require chromatographic separation, generates signals that are directly proportional to the number of NMR-active nuclei in the targeted analyte [4,5], and offers a high degree of assay reproducibility [6] along with reduced uncertainty [7,8].…”

An optimized procedure for metabonomic analysis of rat liver tissue using gas chromatography/time-of-flight mass spectrometry

“…However, urine and blood metabonomics reflect the comprehensive metabolic effects associated with a pathogen or chemical agent stimuli; they are unable to provide the precise perspective of local metabolism and microenvironment [10]. Therefore, tissue-targeted technology has considerable value since many diseases may cause detectable disturbances only to the local metabolic pathways within specific organs [11]. Tissue-targeted metabonomic analyses have been carried out on brain tissue [11][12][13], liver tissue [14][15][16], and kidney tissue [17][18][19].…”

“…Therefore, tissue-targeted technology has considerable value since many diseases may cause detectable disturbances only to the local metabolic pathways within specific organs [11]. Tissue-targeted metabonomic analyses have been carried out on brain tissue [11][12][13], liver tissue [14][15][16], and kidney tissue [17][18][19]. Metabolite extraction is a critical step in tissue metabonomic study, and the chloroform-methanol-water solvent system is considered the preferred method in several reports [20][21][22][23].…”

Metabolomics and Mammalian Cell Culture

“…For animal cells liquid N 2 is used to snap freeze the sample, followed by mechanical disruption in order to release the metabolites (Viant et al, 2005). The next stage of the analysis is to extract the metabolites.…”