Expression pattern of connective tissue growth factor in dorsal root ganglia during chronic nerve compression

Abstract

Objective To investigate the expression of connective tissue growth factor (CTGF) in the nerve cells of dorsal root ganglion (DRG) after chronic sciatic nerve compression.Methods The chronic sciatic nerve constriction injury was made in 40 male SD rats by Mackinnon method.At the 0 week,2nd week,4th week and 6.th week after the operation,L4-L6 DRG that connected to sciatic nerve were harvested.The neurons were separated from the L4-L6 DRG.Reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry were applied to detect the expression and synthesis of CTGF in the neurons from the DRG.Results The expression and synthesis of CTGF were detected in the nerve cells of normal DRG.After chronic compression of the sciatic nerve,the CTGF expression level was 5.527 3 ± 0.013 6,6.056 7 ± 0.141 5 and 4.533 3 ± 0.092 9,respectively,and CTGF synthesis was 13.96 ± 1.23,17.97 ± 1.35 and 15.63 ±0.87,respectively.At the 2nd week after chronic compression of the sciatic nerve,the expression and synthesis of CTGF were increased dramatically.At the 4th week,the expression and synthesis of CTGF were increased obviously and reached the peak.At the 6th week,the expression and synthesis of CTGF were decreased slowly,but higher than on the normal side.Conclusion CTGF not only participates in the pathophysiological process of the nerve cells of DRG after the chronic compression of sciatic nerve,but also plays an important role in protecting the nerve cells. Key words: Sciatic nerve ; Chronic compression ; Dorsal root ganglion ; Connective tissue growth factor