2011 OSU Molecular Life Sciences
Interdisciplinary Graduate Programs Symposium
Poster abstracts
Abstract:
Progranulin (GRN) is a secreted growth factor associated with inflammation and wound repair in peripheral tissues. However, its upregulation in response to acute traumatic brain injury as well as chronic neurodegenerative disorders suggests it also responds to injury in the central nervous system. To determine whether changes in GRN expression accompany acute spinal cord injury (SCI), C57BL/6 mice were subjected to mid-thoracic (T9 level) contusion SCI and analyzed by immunohistochemical and biochemical methods. Whereas spinal cord sections prepared from non-injured laminectomy control animals contained low basal levels of GRN immunoreactivity in gray matter, sections from injured animals contained intense immunoreactivity throughout the injury epicenter that peaked 7-14 days post injury. GRN immunoreactivity colocalized with myeloid cell markers CD11b and CD68, indicating that expression increased primarily in activated microglia and macrophages. Immunoblot analysis confirmed that GRN protein levels rose after injury. On the basis of quantitative polymerase chain reaction analysis, increased protein levels resulted from a 10-fold rise in GRN transcripts. These data demonstrate that GRN is dramatically induced in myeloid cells after experimental SCI and is positioned appropriately both spatially and temporally to influence recovery after injury.
Keywords: Progranulin, Spinal Cord Injury, Inflammation