title: Differential expression of GAP-43 and neurofilament during peripheral nerve regeneration through bio-artificial conduits.
abstract: Nerve conduits are promising alternatives for repairing nerve gaps; they provide a close microenvironment that supports nerve regeneration. In this sense, histological analysis of axonal growth is a determinant to achieve successful nerve regeneration. To evaluate this process, the most-used immunohistochemical markers are neurofilament (NF), β-III tubulin and, infrequently, GAP-43. However, GAP-43 expression in long-term nerve regeneration models is still poorly understood. In this study we analysed GAP-43 expression and its correlation with NF and S-100, using three tissue-engineering approaches with different regeneration profiles. A 10 mm gap was created in the sciatic nerve of 12 rats and repaired using collagen conduits or collagen conduits filled with fibrin-agarose hydrogels or with hydrogels containing autologous adipose-derived mesenchymal stem cells (ADMSCs). After 12 weeks the conduits were harvested for histological analysis. Our results confirm the long-term expression of GAP-43 in all groups. The expression of GAP-43 and NF was significantly higher in the group with ADMSCs. Interestingly, GAP-43 was observed in immature, newly formed axons and NF in thicker and mature axons. These proteins were not co-expressed, demonstrating their differential expression in newly formed nerve fascicles. Our descriptive and quantitative histological analysis of GAP-43 and NFL allowed us to determine, with high accuracy, the heterogenic population of axons at different stages of maturation in three tissue-engineering approaches. Finally, to perform a complete assessment of axonal regeneration, the quantitative immunohistochemical evaluation of both GAP-43 and NF could be a useful quality control in tissue engineering. Copyright © 2014 John Wiley & Sons, Ltd.
authors: Department of Histology (Tissue Engineering Group), University of Granada, Spain.|Instituto de Investigación Biosanitaria ibs, Granada, Spain.|Department of Basic Medical Sciences (Histology, Tissue Engineering Group), Ghent University, Belgium.|Doctoral Programmes in Clinical Medicine and Public Health, University of Granada, Spain, and in Medical Sciences, Ghent University, Belgium.
authors: Víctor
authors: V
authors: Carriel
authors: Department of Histology (Tissue Engineering Group), University of Granada, Spain.|Instituto de Investigación Biosanitaria ibs, Granada, Spain.
authors: Ingrid
authors: I
authors: Garzón
authors: Department of Histology (Tissue Engineering Group), University of Granada, Spain.|Instituto de Investigación Biosanitaria ibs, Granada, Spain.
authors: Antonio
authors: A
authors: Campos
authors: Department of Basic Medical Sciences (Histology, Tissue Engineering Group), Ghent University, Belgium.
authors: Maria
authors: M
authors: Cornelissen
authors: Department of Histology (Tissue Engineering Group), University of Granada, Spain.|Instituto de Investigación Biosanitaria ibs, Granada, Spain.
authors: Miguel
authors: M
authors: Alaminos
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism; D001672:Biocompatible Materials / Q000378:metabolism; D003094:Collagen / Q000378:metabolism; D005337:Fibrin / Q000737:chemistry; D019922:GAP-43 Protein / Q000378:metabolism*; D020100:Hydrogels / Q000737:chemistry; D007382:Intermediate Filaments / Q000378:metabolism*; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology; D009416:Nerve Regeneration / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012583:Schwann Cells / Q000166:cytology; D012584:Sciatic Nerve / Q000473:pathology; D012685:Sepharose / Q000737:chemistry; D023822:Tissue Engineering / Q000379:methods
chemical_list: D001672:Biocompatible Materials; D019922:GAP-43 Protein; D020100:Hydrogels; D005337:Fibrin; D003094:Collagen; D012685:Sepharose
keywords: adipose-derived mesenchymal stem cells; growth-associated protein 43; immunohistochemistry; nerve regeneration; neurofilament; tissue engineering