Turkish Neurosurgery 2023 , Vol 33 , Num 1
Changes in Type II NRG-1 Expression during Regeneration Following Autologous Nerve Transplantation in Rats
Ya-Kang WANG1,Wei-Xia YANG2,Rui LIU1,Jian-Bin GUO1,Yu-Min ZHANG1,Kun LI1, Yao LU1,Junning WANG3
1Xi?an Jiaotong University, Honghui Hospital, Department of Orthopaedics, Xi?an, PR China
2Worker?s Hospital of Aecc Xi?an Aero-Engine LTD, Department of Pathology, Xi?an, PR China
3Xi?an Jiaotong University, Honghui Hospital, Department of Respiratory and Gastroenterology, Xi?an, PR China
DOI : 10.5137/1019-5149.JTN.34913-21.2 AIM: To investigate the changes in type II neuregulin-1 (NRG-1) during the regeneration process following autologous sciatic nerve transplantation in rats.

MATERIAL and METHODS: In total, 40 healthy male Sprague-Dawley (SD) rats of clean grade with body weights between 250 g and 300 g were randomly divided into an experimental and control group, with 20 rats per group. Five time points were set, including the 3rd, 7th, 14th, 21st and 28th days after surgery. In the experimental group, reversed autologous transplantation of the sciatic nerve was performed, while in the control group, the sciatic nerve was simply exposed without autologous transplantation. At the different time points, changes in the rat footprints were observed, the sciatic functional index (SFI) was calculated, changes in the regeneration of the myelin sheath at the nerve end after transplantation were observed by transmission electron microscopy, changes in type II NRG-1 protein expression were detected by a western blot analysis, and changes in type II NRG-1 mRNA expression were detected by real-time PCR.

RESULTS: The SFI in the experimental group was lower than that in the control group at all time points after surgery, and the SFI in the experimental group gradually increased; these differences were statistically significant (p<0.05). The expression of type II NRG-1 protein in the experimental group was significantly increased on the 3rd day after nerve transplantation and peaked on the 7th day, which continued until the 28th day after surgery, indicating a significant difference from the control group (p<0.01). NRG-1 mRNA expression was markedly increased on the 7th day after nerve transplantation, further increased, and peaked on the 14th day (p<0.01). The area of medullated nerve fibers (?m2) in the experimental group significantly differed from that in the control group on the 7th, 14th, 21st and 28th days (p<0.01), and the diameters of the axons in the experimental group notably differed from those in the control group on the 7th, 14th and 21st days (p<0.01).

CONCLUSION: Type II NRG-1 expression peaked between the 3rd day and 14th day after autologous nerve transplantation and is likely involved in the regulation of myelin sheath regeneration during this period. Keywords : Neuregulin-1 (NRG-1), Myelin sheath, Regeneration

Corresponding author : Junning WANG, wangjunningde@163.com, drluyao@163.com