Acute Spinal Cord Injury (ASCI) Metabolomics Through 1H-NMR Spectroscopy: Metabolic alterations with time & treatment
Alka Singh1, Suruchi Singh2, Saloni Raj1, Ravindra Kumar Garg3, Abbas Ali Mahdi4, Raja Roy2, and Rajeshwar Nath Srivastava1

1Orthopaedic Surgery, King George's Medical University, Lucknow, India, 2Centre of Biomedical Research, Lucknow, India, 3Neurology, King George's Medical University, Lucknow, India, 4Biochemistry, King George's Medical University, Lucknow, India

Synopsis

It mainly focuses on finding significant metabolites in serum using 1H NMR based spectroscopic methods and to study the variation of concentration of these metabolites during the recovery of the patient ongoing treatment after surgery. Significant metabolites, namely, lactate, glycine, acetone and succinate were identified using statistical methods (ANOVA along with Mann- Whitney U test) and are found to be elevated during the time of injury. The levels gradually decrease as the patient recovers in an average period of six months.This is a prospective case-control preliminary study on recovery of the patient during acute spinal cord injury.

Purpose

Proton NMR Spectroscopic metabolic profiling has been applied to analyze a variety of metabolites in serum which may be used for evaluating metabolic biomarkers if any that could help to determine the degree of injury, severity and to prognosticate neurologic recovery in Acute Spinal Cord Injury (ASCI).

Introduction

Acute Spinal Cord Injury (ASCI) is a devastating disease that it results into temporary or often permanent physical disabilities resulting into large socio-economic costs on affected family and society. According to WHO 2013 data the incidence of traumatic SCI ranges from 13 to 53 per million populations.1 In most developing countries, very little is known about the exact epidemiology of SCI. In India approx 20,000 new cases per year are registered and major victims are from poor , illiterate population.2 ASCI start a cascade of pathophysiological reaction resulting in inflammation, electrolytic shifts and edema.3 Various experiments on untargeted metabolomic profiling of ASCI in animals strongly indicate that in different metabolic phases, neuronal signalling, stress, and inflammatory metabolites were altered with an obvious relationship which can be taken as useful clue for further human research.

Methods

Spinal trauma patients having a grading ASIA impairment scale A were enrolled for the study. A total of 30 subjects were analysed, 10 were healthy controls (group-0) having no significant pathology. The remaining 20 subjects were cases of ASCI (ASIA impairment scale A) which were operated using Fixation with Stem cell treatment (n=10, group-1) and Fixation without Stem cell treatment (n=10, group-2). All the samples (case and control) were collected at the time of admission of the subject to the hospital and after 6th month follow-up. Ethical clearance was approved by the institutional committee. Blood samples were collected in plain vials and were subjected to centrifugation, the serum was then collected and stored at -800c until analysed. The spectra for serum were acquired using 1D single pulse Carr-Purcell-Meiboom-Grill (CPMG) experiment on BrukerBiospinAvance III 800 MHz NMR spectrometer (BrukerGmBH, Germany). The spectra were quantified after phase and base line correction, and an analysed using one way ANOVA along with Mann-Whitney U test was performed in order to observe the difference between the group 0, 1 & 2 subjects on the basis of the metabolic perturbation. The p-value of ˂0.05 was considered statistically significant.

Result

Significant metabolic alterations were observed among the groups in both injured as well as treated subjects (6th month follow-up). The representative class of proton MR spectra are shown in Figures 1 & 2 respectively. Valine was found to be significant in differentiation of group 1 from group 0. It was found to decrease in subjects operated with stem cell treatment after 6 month while it remained almost constant in control group. Other metabolites which were found to be significant in differentiation were lactate, succinate, glycine and acetone. All these metabolites were found to be elevated at the time of injury and the levels decreased according to patient’s recovery in 6 months. However, the levels for control group were constant during this period (Figure 3). The Mann-Whitney U test allowed the differentiation on the basis of just 3 metabolites, namely valine, acetone and glycine. Valine was significant in differentiating group 1 from healthy individuals. Acetone & glycine were significant in differentiating group 2 from individuals. Acetone alone was responsible to differentiate the Stem cell treatment from conservative treatment, and therefore can be considered as a biomarker for ASCI.

Discussion

Observation of evaluated lactate levels is common in severely injured subjects and shows a dependency on the severity of injury and related to neuropsychological deficits. Glycine plays a pivotal role in development of neuropathic pain and its concentrations and the synoptic cleft is controlled by the glycine transporters. At the time of injury the signalling of pain occurs which may be due to elevated glycine levels. These levels are further observed to decrease as the patients recovers and pain relievers. This is an ongoing study which has started to show some promising results. Till now a small number of cases with only serum samples were analysed and some significant metabolite relationships with disease progression has been observed.

Conclusion

The study is being planned further on larger number of cases with increased follow-ups. Urine and cerebrospinal fluid samples will also be incorporated and compared on the next stage of this study. This would certainly provide a larger perspective in relationships between metabolites and progress of spinal cord injury.

Acknowledgements

The authors are thankful to King George’s Medical University and Centre of Biomedical Research, SGPGIMS, Lucknow, where the present study was conducted.

References

1. Jerome B. et al. International perspectives on spinal cord injury, World Health Organization publication. Http://apps.who.int/iris/bitstream/10665/94192/10/WHO_NMH_VIP_13.03_rum.pdf2013.

2. Singh R, Sharma SC, Mittal R, et al. Traumatic spinal cord injuries in Haryana: an epidemiological study. Indian J Community Med. 2003; 28:184-186.

3. Fujieda Y, et al., Metabolite Profiles Correlate Closely with Neurobehavioral Function in Experimental Spinal Cord Injury in Rats. PLOS ONE. 2012; 7: e43152.

Figures

Figure 1: A representative 1H NMR spectra of serum (at the time of admission) showing assignment in Healthy Controls (Group 0), Fixation with stem-cell (Group 1), Fixation without stem-cell (Group 2).

Figure 2: A representative 1H NMR spectra of serum (at the time of 6th month follow-up) showing assignment in Healthy Controls (Group 0), Fixation with stem-cell (Group 1), Fixation without stem-cell (Group 2).

Figure 3: A graphical representation of significant metabolites among the three groups in serum (collected at the time of admission and 6th month follow-up respectively) showing their respective elevation and depletion.



Proc. Intl. Soc. Mag. Reson. Med. 24 (2016)
2419