Subject(s)
Burns/therapy , Keratinocytes/transplantation , Skin Transplantation/methods , Surgical Mesh , Adolescent , Adult , Aged, 80 and over , Burns/surgery , Cells, Cultured , Cicatrix/prevention & control , Female , Humans , Male , Wound Healing , Young AdultABSTRACT
Bioengineered systems incorporate cultured cells to mimic the substituted tissue. A labeling method is necessary to monitor the survival of transplanted cells within the host. This labeling method must be compatible with the histochemical methods used for morphological analysis. This study assessed (1) The in vitro characteristics of Schwann cells (SCs) labeled with green fluorescent protein (GFP), (2) the in vivo effect of transplanted GFP-SCs in a model of peripheral nerve injury, and (3) the compatibility of GFP-SCs with immunofluorescence histochemical techniques. SCs were retrovirally labeled with GFP and their growth characteristics were compared with those of nontransduced SCs (ntSCs). GFP-SCs were seeded in a resorbable nerve conduit for grafting into a 1-cm gap in rat sciatic nerve. Grafts were harvested after 2 weeks and immunofluorescent staining was performed to measure axonal and SC regeneration distances and to identify GFP-SCs. Results of GFP-SC vitality assays did not vary significantly from those of ntSC assays. GFP-SCs were readily located ex vivo and stimulated significantly better axonal and SC regeneration distances in comparison with empty conduits. These findings show that GFP labeling does not have a deleterious effect on SCs and that it is a useful labeling method for the study of bioengineered systems.
Subject(s)
Cell Survival/physiology , Green Fluorescent Proteins/metabolism , Schwann Cells/pathology , Schwann Cells/transplantation , Sciatic Nerve/pathology , Sciatic Nerve/surgery , Tissue Engineering/methods , Animals , Animals, Newborn , Biomarkers/metabolism , Biomedical Engineering/methods , Cells, Cultured , Green Fluorescent Proteins/genetics , Microscopy, Fluorescence/methods , Nerve Regeneration/physiology , Rats , Rats, Sprague-Dawley , Recombinant Proteins/metabolism , Schwann Cells/metabolism , Sciatic Nerve/injuries , Sciatic Nerve/metabolism , TransplantsABSTRACT
Delivery of neurotrophin-3 (NT-3) to severed sciatic nerves results in specific normalization of atrophied fast 2b gastrocnemius muscle fibres, and promotes preferential neuromuscular junction maturation of fast extensor digitorum longus (EDL). To investigate the selective influence on fast muscle reinnervation due to NT-3 delivery, we analyzed tyrosine kinase C (trkC) mRNA differential expression in EDL and slow soleus motor pools of unoperated rats and at 1-week post-axotomy. Motoneurons (Mns) were identified using retrograde tracers. TrkC mRNA quantification was estimated by silver grain counting. TrkC mRNA expression was higher in EDL than in soleus Mns in unoperated rats. Axotomy decreased trkC mRNA expression only in EDL Mns, this downregulation being prevented by NT-3. These results suggest that differential expression of trkC receptor is the morphological correlate of the preferential effect of NT-3 upon EDL Mns.
