ABSTRACT
BACKGROUND: Chronic nerve compression leads to muscle atrophy and fibrosis. Previous studies mainly focus on its pathogenesis. However, little is known about the dorsal root ganglia(DRG) responses to chronic nerve compression injury. OBJECTIVE: To investigate the effect of chronic sciatic nerve compression on fibrosis of the DRG. METHODS: Animal models of chronic sciatic nerve compression were made in rats according to the method described by Mackinnon. L4-6 ipsilateral and contralateral DRG were harvested 3 weeks post injury. Real-time RT-PCR, immunofluorescence and western blot were performed to determine the expression levels of transforming growth factor-β, connective tissue growth factor, and collagen type I in ipsilateral and contralateral DRG. RESULTS AND CONCLUSION: Three weeks after injury, the m RNA and protein expression of transforming growth factor-β, connective tissue growth factor and collagen type I were increased significantly in the ipsilateral DRG as compared with the contralateral DRG(P < 0.05). Transforming growth factor-β and connective tissue growth factor mainly expressed in DRG neurons and axons, while collagen type I formed a net structure that surrounded DRG neurons and axons. These findings indicate that chronic sciatic nerve compression can induce fibrotic changes in the DRG that appears to be associated with an increase in transforming growth factor-β and connective tissue growth factor expression in DRG neurons.