title: Spinal Cord Injury Suppresses Cutaneous Inflammation: Implications for Peripheral Wound Healing.
abstract: People who suffer a traumatic spinal cord injury (SCI) are at increased risk for developing dermatological complications. These conditions increase cost of care, incidence of rehospitalization, and the risk for developing other infections. The consequences of dermatological complications after SCI are likely exacerbated further by post-injury deficits in neural-immune signaling. Indeed, a functional immune system is essential for optimal host defense and tissue repair. Here, we tested the hypothesis that SCI at high spinal levels, which causes systemic immune suppression, would suppress cutaneous inflammation below the level of injury. C57BL/6 mice received an SCI (T3 spinal level) or sham injury; then one day later complete Freund's adjuvant (CFA) was injected subcutaneously below the injury level. Inflammation was quantified by injecting mice with V-Sense, a perfluorocarbon (PFC) tracer that selectively labels macrophages, followed by in vivo imaging. The total radiant efficiency, which is proportional to the number of macrophages, was measured over a 4-day period at the site of CFA injection. Fluorescent in vivo imaging revealed that throughout the analysis period, the macrophage reaction in SCI mice was reduced ∼50% compared with sham-injured mice. Radiant efficiency data were confirmed using magnetic resonance imaging (MRI), and together the data indicate that SCI significantly impairs subcutaneous inflammation. Future studies should determine whether enhancing local inflammation or boosting systemic immune function can improve the rate or efficiency of cutaneous wound healing in individuals with SCI. Doing so also could limit wound infections or secondary complications of impaired healing after SCI.
authors.affiliation: 1 Neuroscience Graduate Program, The Ohio State University , Columbus, Ohio.|4 Center for Brain and Spinal Cord Repair, The Ohio State University , Columbus, Ohio.
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Marbourg
authors.affiliation: 2 Small Animal Imaging Shared Resources, DHLRI, The Ohio State University , Columbus, Ohio.
authors.forename: Anna
authors.initials: A
authors.lastname: Bratasz
authors.affiliation: 3 Center for Biostatistics, The Ohio State University , Columbus, Ohio.
authors.forename: Xiaokui
authors.initials: X
authors.lastname: Mo
authors.affiliation: 1 Neuroscience Graduate Program, The Ohio State University , Columbus, Ohio.|4 Center for Brain and Spinal Cord Repair, The Ohio State University , Columbus, Ohio.|5 Department of Neuroscience, The Ohio State University , Columbus, Ohio.
authors.forename: Phillip G
authors.initials: PG
authors.lastname: Popovich
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D005466:Fluorocarbons; D007249:Inflammation / Q000000981:diagnostic imaging / Q000276:immunology*; D008264:Macrophages / Q000276:immunology*; D008279:Magnetic Resonance Imaging; D051379:Mice; D008810:Mice, Inbred C57BL; D012871:Skin Diseases / Q000000981:diagnostic imaging / Q000276:immunology*; D013119:Spinal Cord Injuries / Q000000981:diagnostic imaging / Q000276:immunology*; D014945:Wound Healing / Q000276:immunology*
chemical_list: D005466:Fluorocarbons
keywords: fluorocarbons; macrophages; magnetic resonance imaging; spinal cord injury; wound healing