title: Tumor necrosis factor-α-dependent infiltration of macrophages into the dorsal root ganglion in a rat disc herniation model.
abstract: METHODS
  A prospective molecular mechanism of macrophages infiltration in experimental disc herniation.
  
  
  OBJECTIVE
  To investigate the mechanisms of macrophages infiltration into the dorsal root ganglion (DRG) in a rat model of disc herniation.
  
  
  BACKGROUND
  Macrophages infiltrate the DRG after application of nucleus pulposus (NP) on the DRG, and may play an important role in radiculopathy. However, the mechanisms of macrophages infiltration after NP application remain poorly understood.
  
  
  METHODS
  After experimental disc herniation in this study, we investigated changes in the expression of ED1 (a marker of macrophages) and vascular cell adhesion molecule-1 (VCAM-1) in DRG using immunofluorescence. We also investigated the expression of ED1 and VCAM-1 in DRG by treatment with tumor necrosis factor-α (TNF-α) inhibitor at the time of surgery.
  
  
  RESULTS
  We found a massive ED1-positive macrophages infiltrated the DRG, and VCAM-1-like immunoreactivity vessels became evident after NP application. Furthermore, both macrophage infiltration and VCAM-1 expression were prevented by treatment with TNF-α inhibitor at the time of surgery.
  
  
  CONCLUSIONS
  These findings indicated that macrophages infiltration into the DRG was TNF-α-dependent, and might be partly mediated by VCAM-1 in the early stage of experimental lumbar disc herination. Taken together, this study provides important preliminary data suggesting that TNF-α plays an important role in the macrophage infiltration.
  
  
  METHODS
  N/A.
authors: *Department of Orthopedic Surgery, The First Affiliated Hospital, Harbin Medical University, Harbin, P.R. China; and †Department of Radiology, Harbin Children's Hospital, Harbin, P.R. China.
authors: Changcheng
authors: C
authors: You
authors: Kai
authors: K
authors: Zhu
authors: Xiaoqi
authors: X
authors: Liu
authors: Chunyang
authors: C
authors: Xi
authors: Zhipeng
authors: Z
authors: Zhang
authors: Gongping
authors: G
authors: Xu
authors: Jinglong
authors: J
authors: Yan
mesh_terms: D000818:Animals; D002633:Chemotaxis / Q000187:drug effects; D004195:Disease Models, Animal; D053331:Ectodysplasins / Q000378:metabolism; D000068800:Etanercept; D005260:Female; D005727:Ganglia, Spinal / Q000187:drug effects / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D007074:Immunoglobulin G / Q000494:pharmacology; D007405:Intervertebral Disc Displacement / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D008264:Macrophages / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018124:Receptors, Tumor Necrosis Factor; D015398:Signal Transduction; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000378:metabolism*; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism
chemical_list: D053331:Ectodysplasins; D007074:Immunoglobulin G; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D000068800:Etanercept