Expression patterns and functional evaluation of RGMa during the early phase of peripheral nerve regeneration using the mouse median nerve model

Article type: Research Article

Authors: Jaminet, Patrick^{a; *} | Schäufele, Martin^b | Mager, Alice^c | Fornaro, Michele^d | Ronchi, Giulia^d | Geuna, Stefano^d | Schaller, Hans-Eberhard^b | Rosenberger, Peter^c | Köhler, David^c

Affiliations: [a] Department of Plastic Surgery and Hand Surgery, Klinikum Westmünsterland, Borken, Germany | [b] Department of Plastic, Hand and Reconstructive Surgery, Burn Center, BG-Trauma Center, Eberhard Karls University of Tübingen, Tübingen, Germany | [c] Department of Anesthesiology and Intensive Care Medicine, University Hospital Tübingen, Eberhard Karls University of Tübingen, Tübingen, Germany | [d] Dipartimento di Scienze Cliniche e Biologiche & Neuroscience Institute Cavalieri Ottolenghi, Università di Torino, Italy

Correspondence: [*] Corresponding author: PD Dr. Patrick JAMINET, Department of Plastic Surgery, Hand Surgery, Klinikum Westmünsterland, 46325 Borken, Germany. Tel.: +49 2861 97 3391; Fax: +49 2861 97 53391; E-mail: patrickjaminet@gmail.com.

Abstract: Background:In this study, we evaluate the role of RGMa (Repulsive Guidance Molecule a) during peripheral nerve regeneration using the mouse median nerve model. Methods:By real-time PCR and Western Blot analysis, we examined expression changes of RGMa mRNA and RGMa protein in neural tissue after transection and microsurgical repair of the mouse median nerve distal to the transection site. We evaluated histomorphometrical changes in neural tissue distal to the injury site and functional recovery of the grasping force after median nerve transection and repair in wild-type mice and RGMa+/– heterozygous mice. Results:RT-PCR revealed a 1,8 fold increase of RGMa mRNA two weeks and a 4,4 fold increase of RGMa mRNA 3 weeks after nerve transection and repair in the nerve segment distal to the injury site. In Western blot analysis, we could show a high increase of RGMa in the nerve segment distal to the injury site at day 14. Histomorphometrical analysis showed significant differences between wild-type animals and heterozygous animals. The absolute number of myelinated fibres was significantly higher in operated heterozygous RGMa+/– animals compared to operated wildtye animals. Using the functional grasping test, we could demonstrate that peripheral nerve regeneration is significantly diminished in heterozygous RGMa+/– mice. Conclusions:Employing the mouse median nerve model in transgenic animals, we demonstrate that RGMa plays an important role during peripheral nerve regeneration.

Keywords: Median nerve model, transgenic, peripheral nervous system, RGMa, grasping test

Keywords: DGUV (Deutsche Gesetzliche Unfallversicherung)

Keywords: FR 175

DOI: 10.3233/RNN-190913

Journal: Restorative Neurology and Neuroscience, vol. 37, no. 3, pp. 265-272, 2019