Zinc Regulates Glucose Metabolism of the Spinal Cord and Neurons and Promotes Functional Recovery after Spinal Cord Injury through the AMPK Signaling Pathway

Oxid Med Cell Longev. 2021 Jul 31:2021:4331625. doi: 10.1155/2021/4331625. eCollection 2021.

Abstract

Spinal cord injury (SCI) is a traumatic disease that can cause severe nervous system dysfunction. SCI often causes spinal cord mitochondrial dysfunction and produces glucose metabolism disorders, which affect neuronal survival. Zinc is an essential trace element in the human body and plays multiple roles in the nervous system. This experiment is intended to evaluate whether zinc can regulate the spinal cord and neuronal glucose metabolism and promote motor functional recovery after SCI. Then we explore its molecular mechanism. We evaluated the function of zinc from the aspects of glucose uptake and the protection of the mitochondria in vivo and in vitro. The results showed that zinc elevated the expression level of GLUT4 and promoted glucose uptake. Zinc enhanced the expression of proteins such as PGC-1α and NRF2, reduced oxidative stress, and promoted mitochondrial production. In addition, zinc decreased neuronal apoptosis and promoted the recovery of motor function in SCI mice. After administration of AMPK inhibitor, the therapeutic effect of zinc was reversed. Therefore, we concluded that zinc regulated the glucose metabolism of the spinal cord and neurons and promoted functional recovery after SCI through the AMPK pathway, which is expected to become a potential treatment strategy for SCI.

MeSH terms

  • Adenylate Kinase / metabolism*
  • Animals
  • Female
  • Glucose / metabolism*
  • Glucose Transporter Type 4 / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mitochondria / drug effects
  • Mitochondria / metabolism
  • NF-E2-Related Factor 2 / metabolism
  • Neurons / drug effects
  • Neurons / metabolism*
  • PC12 Cells
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha / metabolism
  • Rats
  • Signal Transduction
  • Spinal Cord / cytology
  • Spinal Cord / metabolism
  • Spinal Cord / physiology
  • Spinal Cord Injuries / drug therapy
  • Spinal Cord Injuries / metabolism*
  • Spinal Cord Regeneration
  • Zinc / pharmacology*
  • Zinc / therapeutic use

Substances

  • Glucose Transporter Type 4
  • NF-E2-Related Factor 2
  • Nfe2l2 protein, mouse
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha
  • Slc2a4 protein, mouse
  • Adenylate Kinase
  • Glucose
  • Zinc