Overexpression of Neuregulin-1 (NRG-1) Gene Contributes to Surgical Repair of Brachial Plexus Injury After Contralateral C7 Nerve Root Transfer in Rats
Authors: Jin-Lan Jiang
Dian-Hui Xiu
Zong-Qiang Wang
Gui-Feng Liu
Journal: Medical Science Monitor (2018)
Discipline: CLINICAL MEDICINE
Keywords: Surgeons; contralateral C7; nerve graft; sensation; movement
Affiliations: Medical Department, China-Japan Union Hospital of Jilin University, Changchun, Jilin, China (mainland)., Department of Radiology, China-Japan Union Hospital of Jilin University, Changchun, Jilin, China (mainland)., Department of Orthopedics, China-Japan Union Hospital of Jilin University, Changchun, Jilin, China (mainland)., Scientific Research Center, China-Japan Union Hospital of Jilin University, Changchun, Jilin, China (mainland).

Abstract:  BACKGROUND Surgeons usually transfer the contralateral C7 to the median nerve on the injured side via a nerve graft to recover sensation and movement in a paralyzed hand. The purpose of our study was to determine whether NRG-1 affects the recovery of nerve function in brachial plexus injury after contralateral C7 nerve root transfer in a rat model. MATERIAL AND METHODS An injury model of left brachial plexus and contralateral C7 nerve root transfer was established. Four weeks after the operation, NRG-1 expression was examined by reverse transcription quantitative polymerase chain reaction and Western blot analysis. The diameter rate differences of the healthy limb and affected limb were estimated. The postoperative mass of the left latissimus dorsi, triceps, extensor carpi radialis brevis, and musculus extensor digitorum were examined. The number of nerve fibers and typical area of the affected side were assessed. Postoperative left motor nerve conduction velocity (MNCV) and motor nerve action potential (MNAP) were tested by use of a biological information recording and collecting system. RESULTS Eukaryotic expression plasmid of pcDNA4/myc/A-NRG-1 was successfully constructed, and NRG-1 was overexpressed. Compared with the model group, the NRG-1 group had a lower rate of differences of the limbs; higher mass of left latissimus dorsi, triceps, extensor carpi radialis brevis, and musculus extensor digitorum; more nerve fibers and larger typical area in the affected side, left MNCV, and MNAP; and wider CSA of the left triceps. CONCLUSIONS These results demonstrated that NRG-1 can promote recovery of nerve function in brachial plexus injury after contralateral C7 nerve root transfer in rats. 

Retracted: Yes

PubPeer comments:
 Figure 2A. These two pairs of bands are very similar.  , 
 #1 Dear Dr Parashorea Tomentella, Thank you for your concern about the similarity of PCR product on gel electrophoresis. I am the first author of this article, Zongqiang Wang. For some reason, the e-mail registration audit failed, so I used anonymous registration. Due to the poor laboratory conditions in 2016, we used the poor resolution of our gel imaging system (Tianneng, China, Tanon-4600SF), which caused the high similarity of PCR bands, especially for the pair of 9 ,11, 10 and 12. However, we can tell the difference between the two bands in each pair. We screenshotted the Figure 2 in the pdf file, copy it in word (Fig 1). Then inserted a Picture box (as indicated in Fig 2), and put it on the band of 9, set it without color filling. Reset it with a proper size, keeping the box line along with the band borders; then copied same box and replace it on band 11, under such backgrounds, we found (magnify the view page of the word file, Fig 3) the difference between band 9 and band 11: the red and blue arrows point differently within the two red vertical line. We can also find that the left and right edges of the blue arrow point differently as well as band 10 and band 12 with the same way. Please re-check the difference in the figure, at your most convenient moment, with above-mentioned method or other methods. Thank you very much! Sincerely yours Dr Zongqiang Wang  Fig 1  Fig 2  Fig 3 , 
 #2 Thank you for your reply. However, after checking your figures, I still think these two pairs of bands are very similar. Could the authors show a photo of the original results? , 
 Retracted [22 September 2021] . *Retracted on the author s request:  We would like to withdraw our manuscript. We restarted the project for further study last year, we found that the results in this study are not solid enough and need to be further explored. * ,