title: Characterizing phospholipase A2-induced spinal cord injury-a comparison with contusive spinal cord injury in adult rats.
abstract: To assess whether phospholipase A2 (PLA2) plays a role in the pathogenesis of spinal cord injury (SCI), we compared lesions either induced by PLA2 alone or by a contusive SCI. At 24-h post-injury, both methods induced a focal hemorrhagic pathology. The PLA2 injury was mainly confined within the ventrolateral white matter, whereas the contusion injury widely affected both the gray and white matter. A prominent difference between the two models was that PLA2 induced a massive demyelination with axons remaining in the lesion area, whereas the contusion injury induced axonal damage and myelin breakdown. At 4 weeks, no cavitation was found within the PLA2 lesion, and numerous axons were myelinated by host-migrated Schwann cells. Among them, 45% of animals had early transcranial magnetic motor-evoked potential (tcMMEP) responses. In contrast, the contusive SCI induced a typical centralized cavity with reactive astrocytes forming a glial border. Only 15% of rats had early tcMMEP responses after the contusion. BBB scores were similarly reduced in both models. Our study indicates that PLA2 may play a unique role in mediating secondary SCI likely by targeting glial cells, particularly those of oligodendrocytes. This lesion model could also be used for studying demyelination and remyelination in the injured spinal cord associated with PLA2-mediated secondary SCI.
authors.affiliation: Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, 950 W Walnut St, R2 Building, Room 402, Indianapolis, IN 46202, USA. Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA. Kentucky Spinal Cord Injury Research Center, University of Louisville School of Medicine, Louisville, KY 40292, USA. Department of Neurological Surgery, University of Louisville School of Medicine, Louisville, KY 40292, USA.
authors.forename: Nai-Kui
authors.initials: NK
authors.lastname: Liu
authors.forename: William Lee
authors.initials: WL
authors.lastname: Titsworth
authors.forename: Yi Ping
authors.initials: YP
authors.lastname: Zhang
authors.forename: Aurela I
authors.initials: AI
authors.lastname: Xhafa
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Shields
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Xu
keywords: Axonal degeneration; Demyelination; Phospholipase A2; Schwann cells; Spinal cord injury