TY - JOUR
T1 - A comparative morphological, electrophysiological and functional analysis of axon regeneration through peripheral nerve autografts genetically modified to overexpress BDNF, CNTF, GDNF, NGF, NT3 or VEGF
AU - Hoyng, Stefan A
AU - De Winter, Fred
AU - Gnavi, Sara
AU - de Boer, Ralph
AU - Boon, Lennard I
AU - Korvers, Laura M
AU - Tannemaat, Martijn R
AU - Malessy, Martijn J A
AU - Verhaagen, J.
N1 - Copyright © 2014 Elsevier Inc. All rights reserved.
PY - 2014/11
Y1 - 2014/11
N2 - The clinical outcome of microsurgical repair of an injured peripheral nerve with an autograft is suboptimal. A key question addressed here is: can axon regeneration through an autograft be further improved? In this article the impact of six neurotrophic factors (BDNF, CNTF, GDNF, NGF, NT3 or VEGF) on axon regeneration was compared after delivery to a 1cm long nerve autograft by gene therapy. To distinguish between early and late effects, regeneration was assessed at 2 and 20weeks post-surgery by histological, electrophysiological and functional analysis. BDNF, GDNF and NGF exhibited a spectrum of effects, including early stimulatory effects on axons entering the autograft and excessive axon growth and Schwann cell proliferation at 20weeks post-surgery. Persistent expression of these factors in autografts interfered with target cell reinnervation and functional recovery in a modality specific way. Autografts overexpressing VEGF displayed hypervascularization, while grafts transduced with CNTF and NT3 were indistinguishable from control grafts. These three factors did not have detectable pro-regenerative effects. In conclusion, autograft-based repair combined with gene therapy for three of the six growth factors investigated (BDNF, GDNF, NGF) showed considerable promise since these factors enhanced modality specific axon outgrowth in autografts. The remarkable and selective effects of BDNF, GDNF and NGF on motor or sensory regeneration will be exploited in future experiments that aim to carefully regulate their temporal and spatial expression since this has the potential to overcome the adverse effects on long-distance regeneration observed after uncontrolled delivery.
AB - The clinical outcome of microsurgical repair of an injured peripheral nerve with an autograft is suboptimal. A key question addressed here is: can axon regeneration through an autograft be further improved? In this article the impact of six neurotrophic factors (BDNF, CNTF, GDNF, NGF, NT3 or VEGF) on axon regeneration was compared after delivery to a 1cm long nerve autograft by gene therapy. To distinguish between early and late effects, regeneration was assessed at 2 and 20weeks post-surgery by histological, electrophysiological and functional analysis. BDNF, GDNF and NGF exhibited a spectrum of effects, including early stimulatory effects on axons entering the autograft and excessive axon growth and Schwann cell proliferation at 20weeks post-surgery. Persistent expression of these factors in autografts interfered with target cell reinnervation and functional recovery in a modality specific way. Autografts overexpressing VEGF displayed hypervascularization, while grafts transduced with CNTF and NT3 were indistinguishable from control grafts. These three factors did not have detectable pro-regenerative effects. In conclusion, autograft-based repair combined with gene therapy for three of the six growth factors investigated (BDNF, GDNF, NGF) showed considerable promise since these factors enhanced modality specific axon outgrowth in autografts. The remarkable and selective effects of BDNF, GDNF and NGF on motor or sensory regeneration will be exploited in future experiments that aim to carefully regulate their temporal and spatial expression since this has the potential to overcome the adverse effects on long-distance regeneration observed after uncontrolled delivery.
U2 - 10.1016/j.expneurol.2014.08.002
DO - 10.1016/j.expneurol.2014.08.002
M3 - Article
C2 - 25128265
SN - 0014-4886
VL - 261
SP - 578
EP - 593
JO - Experimental Neurology
JF - Experimental Neurology
ER -