Assessment of spinal cord glutathione levels and regulatory pathways at 1- and 3-days post-injury after 60 kDyn T9 spinal-contusion using the Infinite Horizons impactor in male and female 4- and 14-month old mice and evaluating n-acetylcysteine amide as a therapy in female 4- and 14-month old mice to restore spinal cord levels of glutathione and to protect against oxidative stress and affect locomotor outcomes and thermal sensitivity by 28-days after spinal cord injury.

DOI:10.34945/F5XS31

DATASET CITATION

Stewart A. N., Glaser E. P., Mott C. A., Bailey W. M., Sullivan P. G., Patel S. P., Gensel J. C. (2022) Assessment of spinal cord glutathione levels and regulatory pathways at 1- and 3-days post-injury after 60 kDyn T9 spinal-contusion using the Infinite Horizons impactor in male and female 4- and 14-month old mice and evaluating n-acetylcysteine amide as a therapy in female 4- and 14-month old mice to restore spinal cord levels of glutathione and to protect against oxidative stress and affect locomotor outcomes and thermal sensitivity by 28-days after spinal cord injury.. ODC-SCI:731 http://doi.org/10.34945/F5XS31

ABSTRACT

STUDY PURPOSE: The purpose of this study was to evaluate the role of advanced age at the time of spinal cord injury (SCI) on antioxidant defense, with an emphasis on glutathione synthesis and metabolism. Further, this study aimed to determine if enhancing spinal levels of glutathione using the cysteine supplement, n-acetylcysteine amide (NACA), would confer age-dependent effects on functional and histological outcomes.

DATA COLLECTED: Levels of spinal glutathione were deterred in sham and injured mice at 1- and 3-days post-injury (dpi). Further, the relative protein abundance of glutathione synthetase, peroxidase, reductase, and glutamyl-cysteine ligase were determined on western blot. Activity assays were used to determine the function of glutathione peroxidase and reductase at 1- and 3-dpi. Accumulation of oxidative stress using dot blots against 3-nitrotyrosine or 4-hydroxynonenol were obtained. Mice were treated with n-acetylcysteine amide and spinal cord levels of glutathione were determined both in naive 4-month-old mice and after SCI in 4- and 14-month-old mice and 1-dpi. Next, mice were treated with NACA for 3-dpi and were allowed to recover for 28-days. Locomotor functions were assessed on the BMS and horizontal ladder, and the Hargreaves test of thermal hypersensitivity was used to determine effects on SCI-induced pain. Lesion outcomes and neuron survival were assessed in tissue sections.

CONCLUSIONS: Older spinal cords have less glutathione prior to SCI compared to younger counterparts, and do not exhibit a strong decline in glutathione after injury. In contrast, younger spinal cords exhibit an injury-induced depletion by 3-dpi. Younger, but not older, spinal cords respond by up-regulating antioxidant activity of glutathione peroxidase which is independent of protein abundance. Treating SCI with NACA did not affect outcomes in younger mice, but trended towards a toxic effect on all outcomes in older mice. We conclude that being older at time of SCI does decrease antioxidant capacity but treatment using NACA to restore glutathione levels exerts unanticipated toxic trends that may, or may not, be associated with NACAs effects on glutathione.

KEYWORDS

redox activity; aging; Sex Difference; Neuroprotection; Oxidative Stress

PROVENANCE / ORIGINATING PUBLICATIONS

• Andrew N. Stewart, Ethan P. Glaser, Caitlin A. Mott, William M. Bailey, Patrick G. Sullivan, Samir P. Patel, and John C. Gensel. Advanced Age and Neurotrauma Diminish Glutathione and Impair Antioxidant Defense after Spinal Cord Injury. Journal of Neurotrauma.Aug 2022. 1075-1089. http://doi.org/10.1089/neu.2022.0010

• Andrew N. Stewart, Ethan P. Glaser, William M. Bailey, and John C. Gensel. Immunoglobulin G Is Increased in the Injured Spinal Cord in a Sex- and Age-Dependent Manner. Journal of Neurotrauma. Aug 2022. 1090-1098. http://doi.org/10.1089/neu.2022.0011

RELEVANT LINKS

NOTES

DATASET INFO

Contact: Stewart Andrew (Andrew.N.Stewart@uky.edu)

Lab: Gensel Lab (Nero)

ODC-SCI Accession:731

Records in Dataset: 198

Fields per Record: 82

Last updated: 2022-09-13

Date published: 2022-09-13

Downloads: 27

Files: 2

LICENSE

Creative Commons Attribution License (CC-BY 4.0)

FUNDING AND ACKNOWLEDGEMENTS

The Craig H. Neilsen Foundation #465079, National Institute of Neurological Disorders and Stroke (NINDS) of the National Institutes of Health (NIH) grants R01NS091582 and F32NS111241, National Institute on Alcohol Abuse and Alcoholism Training Grant T32AA027488, University of Kentucky Neuroscience Research Priority Area ANS

CONTRIBUTORS

Stewart, Andrew N.

University of Kentucky, College of Medicine, Department of Physiology, Spinal Cord and Brain Injury Research Center, Lexington, Kentucky, 40536, USA

Glaser, Ethan P.

University of Kentucky, College of Medicine, Department of Physiology, Spinal Cord and Brain Injury Research Center, Lexington, Kentucky, 40536, USA

Mott, Caitlin A.

University of Kentucky, College of Medicine, Department of Physiology, Spinal Cord and Brain Injury Research Center, Lexington, Kentucky, 40536, USA

Bailey, William M.

University of Kentucky, College of Medicine, Department of Physiology, Spinal Cord and Brain Injury Research Center, Lexington, Kentucky, 40536, USA

Sullivan, Patrick G.

University of Kentucky, College of Medicine, Department of Neuroscience, Spinal Cord and Brain Injury Research Center, Lexington, Kentucky, 40536, USA

Patel, Samir P.

University of Kentucky, College of Medicine, Department of Physiology, Spinal Cord and Brain Injury Research Center, Lexington, Kentucky, 40536, USA

Gensel, John C.

University of Kentucky, College of Medicine, Department of Physiology, Spinal Cord and Brain Injury Research Center, Lexington, Kentucky, 40536, USA