title: Dexamethasone enhanced functional recovery after sciatic nerve crush injury in rats.
abstract: Dexamethasone is currently used for the treatment of peripheral nerve injury, but its mechanisms of action are not completely understood. Inflammation/immune response at the site of nerve lesion is known to be an essential trigger of the pathological changes that have a critical impact on nerve repair and regeneration. In this study, we observed the effects of various doses of dexamethasone on the functional recovery after sciatic nerve crush injury in a rat model. Motor functional recovery was monitored by walking track analysis and gastrocnemius muscle mass ratio. The myelinated axon number was counted by morphometric analysis. Rats administered dexamethasone by local intramuscular injection had a higher nerve function index value, increased gastrocnemius muscle mass ratio, reduced Wallerian degeneration severity, and enhanced regenerated myelinated nerve fibers. Immunohistochemical analysis was performed for CD3 expression, which is a marker for T-cell activation, and infiltration in the sciatic nerve. Dexamethasone-injected rats had fewer CD3-positive cells compared to controls. Furthermore, we found increased expression of GAP-43, which is a factor associated with development and plasticity of the nervous system, in rat nerves receiving dexamethasone. These results provide strong evidence that dexamethasone enhances sciatic nerve regeneration and function recovery in a rat model of sciatic nerve injury through immunosuppressive and potential neurotrophic effects.
authors.affiliation: Department of Neurology, Beijing Tsinghua Changgung Hospital, Medical Center, Tsinghua University, No. 168 Li Tang Road, Changping District, Beijing 102218, China.
authors.forename: Xinhong
authors.initials: X
authors.lastname: Feng
authors.affiliation: Department of Spine Surgery, Aviation General Hospital of China Medical University, Beijing Institute of Translational Medicine, Chinese Academy of Sciences, No. 3 Anwai Beiyuan Road, Chaoyang District, Beijing 100012, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yuan
mesh_terms: D000818:Animals; D017252:CD3 Complex / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology*; D004195:Disease Models, Animal; D019922:GAP-43 Protein / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism; D009409:Nerve Crush; D009413:Nerve Fibers, Myelinated / Q000187:drug effects / Q000378:metabolism; D059348:Peripheral Nerve Injuries / Q000188:drug therapy* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000187:drug effects*; D012584:Sciatic Nerve / Q000187:drug effects* / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism; D014855:Wallerian Degeneration / Q000188:drug therapy* / Q000378:metabolism
chemical_list: D017252:CD3 Complex; D019922:GAP-43 Protein; D003907:Dexamethasone
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