Knockout of ALOX12 protects against spinal cord injury-mediated nerve injury by inhibition of inflammation and apoptosis

Biochem Biophys Res Commun. 2019 Aug 27;516(3):991-998. doi: 10.1016/j.bbrc.2019.06.118. Epub 2019 Jul 2.

Abstract

Spinal cord injury (SCI) is terrible damage leading to the deficiencies and results in infinite inconvenience to sufferers. The effective treatment for SCI still meets a larger number of problems. Herein, the underlying molecular mechanism and novel therapy of SCI are urgently to investigate. Arachidonate 12-lipoxygenase (ALOX12) is widely expressed in various cell types and plays important role in modulating different cellular processes, such as platelet aggregation, cell migration and cancer cell proliferation. Nevertheless, the effects of ALOX12 on SCI are unclear. In the study, SCI model was established in wild type (WT) mice and ALOX12 knockout mice. First, ALOX12 expression was up-regulated in spinal cord tissues of WT mice after SCI. ALOX12-knockout mice exhibited improved behavior after SCI operation. Glial activation triggered by SCI was also alleviated in mice with the loss of ALOX12, as evidenced by the down-regulated expression of glial fibrillary acidic protein (GFAP) and Iba-1 in spinal cord samples. Further, SCI-induced inflammation was markedly prevented in ALOX12-knockout mice through blocking inhibitor of NF-κB α (IκBα)/nuclear factor-κB (NF-κB) pathway signaling. Additionally, reducing ALOX12 expression attenuated apoptosis in spinal cord tissues of SCI mice by decreasing Cyto-c, cleaved Caspase-3 and poly (ADP-ribose) polymerases (PARP) expression. The protective role of ALOX12-decrease against SCI was verified in LPS-incubated glial cells through repressing inflammatory response and apoptotic formation. Moreover, transgenic mice with ALOX12 over-expression showed accelerated SCI, associated with intensified inflammation and apoptosis. Based on these results, strategies for inhibiting ALOX12 could be used to prevent SCI development by repressing inflammation and apoptosis.

Keywords: ALOX12; Apoptosis; Glial activation; Inflammation; Spinal cord injury (SCI).

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Apoptosis / genetics
  • Arachidonate 12-Lipoxygenase / deficiency
  • Arachidonate 12-Lipoxygenase / genetics*
  • Calcium-Binding Proteins / genetics
  • Calcium-Binding Proteins / metabolism
  • Caspase 3 / genetics
  • Caspase 3 / metabolism
  • Cytochromes c / genetics
  • Cytochromes c / metabolism
  • Gene Expression Regulation*
  • Glial Fibrillary Acidic Protein / genetics
  • Glial Fibrillary Acidic Protein / metabolism
  • Lipopolysaccharides / pharmacology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Microfilament Proteins / genetics
  • Microfilament Proteins / metabolism
  • NF-KappaB Inhibitor alpha / genetics
  • NF-KappaB Inhibitor alpha / metabolism
  • NF-kappa B / genetics
  • NF-kappa B / metabolism
  • Neuroglia / drug effects
  • Neuroglia / metabolism
  • Neuroglia / pathology
  • Poly(ADP-ribose) Polymerases / genetics
  • Poly(ADP-ribose) Polymerases / metabolism
  • Signal Transduction
  • Spinal Cord / enzymology*
  • Spinal Cord / pathology
  • Spinal Cord Injuries / enzymology
  • Spinal Cord Injuries / genetics*
  • Spinal Cord Injuries / pathology
  • Spinal Cord Injuries / prevention & control*

Substances

  • Aif1 protein, mouse
  • Calcium-Binding Proteins
  • Glial Fibrillary Acidic Protein
  • Lipopolysaccharides
  • Microfilament Proteins
  • NF-kappa B
  • glial fibrillary astrocytic protein, mouse
  • NF-KappaB Inhibitor alpha
  • Cytochromes c
  • Arachidonate 12-Lipoxygenase
  • Poly(ADP-ribose) Polymerases
  • Casp3 protein, mouse
  • Caspase 3