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Peripheral nerve regeneration: a current perspective.

Radtke C, Vogt PM - Eplasty (2009)

Bottom Line: Olfactory ensheathing cells can integrate and participate in neural repair in both spinal cord and peripheral nerve.They promote axonal sprouting and contribute to remyelination associated with appropriate axon nodal sodium channel clustering necessary for proper impulse conduction.These experimental observations suggest that adjunct cell transplantation with microsurgical repair should be considered as a possible tool in peripheral nerve repair.

View Article: PubMed Central - PubMed

Affiliation: Department of Plastic, Hand and Reconstructive Surgery, Hannover Medical School, 30625 Hannover, Carl-Neuberg Strasse 1, Hannover, Germany. Radtke.Christine@MH-Hannover.de

ABSTRACT

Objective: Nerve regenerative is a complex problem and cell therapy strategies are being developed to enhance axonal regeneration. One approach is to transplant peripheral myelin-forming cells (Schwann cells or olfactory ensheathing cells) that can secrete neurotrophic factors and participate in remyelination of regenerated axons. The objectives of this report are to first review the basic regeneration properties of myelinated axons. Next, to review studies that show functional improvement after transplantation of peripheral myelinating cells in the injured spinal cord. The final objective is to review recent studies using this approach as an adjunct cell therapy for microsurgical repair of peripheral nerve.

Methods: Schwann cells and olfactory ensheathing cells were transplanted into injured spinal cord and peripheral nerve. In the microsurgical repair studies, rat sciatic nerves were repaired with epineural sutures (10.0). Olfactory ensheathing cells were transplanted in the experimental group at the time of repair. Histological and behavioral assessment was carried out at 5 weeks postsurgery.

Results: Experimental transplantation of olfactory ensheathing cells at the time of microsurgical repair of peripheral nerve leads to increased axonal regeneration across the repair site and improved functional outcome.

Conclusions: Olfactory ensheathing cells can integrate and participate in neural repair in both spinal cord and peripheral nerve. They promote axonal sprouting and contribute to remyelination associated with appropriate axon nodal sodium channel clustering necessary for proper impulse conduction. These experimental observations suggest that adjunct cell transplantation with microsurgical repair should be considered as a possible tool in peripheral nerve repair.

No MeSH data available.


Related in: MedlinePlus

(A) Electron micrograph demonstrating typical peripheral myelinating axon in a cross section; note the densely packed myelin sheaths around the axon. In addition, characteristic extracellular collagen can be seen in the outer margins. Scale bar = 2 μm. (B) Dissociated single axons with neurofilament (green) and sodium channel staining for sodium channel subtype Nav 1.6 (red). Accumulation of Nav 1.6 is indicative for nodes of Ravier (arrows). Scale bar = 4 μm. (C) Subconfluent culture of olfactory ensheathing cells stained with p75NGFR demonstrating characteristic morphology with bipolar shape. Scale bar = 40 μm.
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Figure 1: (A) Electron micrograph demonstrating typical peripheral myelinating axon in a cross section; note the densely packed myelin sheaths around the axon. In addition, characteristic extracellular collagen can be seen in the outer margins. Scale bar = 2 μm. (B) Dissociated single axons with neurofilament (green) and sodium channel staining for sodium channel subtype Nav 1.6 (red). Accumulation of Nav 1.6 is indicative for nodes of Ravier (arrows). Scale bar = 4 μm. (C) Subconfluent culture of olfactory ensheathing cells stained with p75NGFR demonstrating characteristic morphology with bipolar shape. Scale bar = 40 μm.

Mentions: Peripheral myelinated axons (Fig1A) are myelinated by Schwann cells, which form a single myelin segment or internode. This is in contrast to myelin in the CNS, which is formed by the oligodendrocyte and sends out several processes to form numerous myelin segments. A basal lamina with laminin on its internal surface surrounds each myelinated axon in the PNS. Slower conducting nonmyelinated axons in the peripheral nerve responsible for pain and temperature (C-fibers) are associated with Schwann cells, which surround groups of these fibers but do not form myelin. Thus, a continuous basal lamina tube surrounds individual myelinated fibers and groups of nonmyelinated fibers for the entire length of the nerve. Another unique feature of peripheral nerve as opposed to central white matter is the deposition of extracellular collagen in the endoneurial compartment.


Peripheral nerve regeneration: a current perspective.

Radtke C, Vogt PM - Eplasty (2009)

(A) Electron micrograph demonstrating typical peripheral myelinating axon in a cross section; note the densely packed myelin sheaths around the axon. In addition, characteristic extracellular collagen can be seen in the outer margins. Scale bar = 2 μm. (B) Dissociated single axons with neurofilament (green) and sodium channel staining for sodium channel subtype Nav 1.6 (red). Accumulation of Nav 1.6 is indicative for nodes of Ravier (arrows). Scale bar = 4 μm. (C) Subconfluent culture of olfactory ensheathing cells stained with p75NGFR demonstrating characteristic morphology with bipolar shape. Scale bar = 40 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2770804&req=5

Figure 1: (A) Electron micrograph demonstrating typical peripheral myelinating axon in a cross section; note the densely packed myelin sheaths around the axon. In addition, characteristic extracellular collagen can be seen in the outer margins. Scale bar = 2 μm. (B) Dissociated single axons with neurofilament (green) and sodium channel staining for sodium channel subtype Nav 1.6 (red). Accumulation of Nav 1.6 is indicative for nodes of Ravier (arrows). Scale bar = 4 μm. (C) Subconfluent culture of olfactory ensheathing cells stained with p75NGFR demonstrating characteristic morphology with bipolar shape. Scale bar = 40 μm.
Mentions: Peripheral myelinated axons (Fig1A) are myelinated by Schwann cells, which form a single myelin segment or internode. This is in contrast to myelin in the CNS, which is formed by the oligodendrocyte and sends out several processes to form numerous myelin segments. A basal lamina with laminin on its internal surface surrounds each myelinated axon in the PNS. Slower conducting nonmyelinated axons in the peripheral nerve responsible for pain and temperature (C-fibers) are associated with Schwann cells, which surround groups of these fibers but do not form myelin. Thus, a continuous basal lamina tube surrounds individual myelinated fibers and groups of nonmyelinated fibers for the entire length of the nerve. Another unique feature of peripheral nerve as opposed to central white matter is the deposition of extracellular collagen in the endoneurial compartment.

Bottom Line: Olfactory ensheathing cells can integrate and participate in neural repair in both spinal cord and peripheral nerve.They promote axonal sprouting and contribute to remyelination associated with appropriate axon nodal sodium channel clustering necessary for proper impulse conduction.These experimental observations suggest that adjunct cell transplantation with microsurgical repair should be considered as a possible tool in peripheral nerve repair.

View Article: PubMed Central - PubMed

Affiliation: Department of Plastic, Hand and Reconstructive Surgery, Hannover Medical School, 30625 Hannover, Carl-Neuberg Strasse 1, Hannover, Germany. Radtke.Christine@MH-Hannover.de

ABSTRACT

Objective: Nerve regenerative is a complex problem and cell therapy strategies are being developed to enhance axonal regeneration. One approach is to transplant peripheral myelin-forming cells (Schwann cells or olfactory ensheathing cells) that can secrete neurotrophic factors and participate in remyelination of regenerated axons. The objectives of this report are to first review the basic regeneration properties of myelinated axons. Next, to review studies that show functional improvement after transplantation of peripheral myelinating cells in the injured spinal cord. The final objective is to review recent studies using this approach as an adjunct cell therapy for microsurgical repair of peripheral nerve.

Methods: Schwann cells and olfactory ensheathing cells were transplanted into injured spinal cord and peripheral nerve. In the microsurgical repair studies, rat sciatic nerves were repaired with epineural sutures (10.0). Olfactory ensheathing cells were transplanted in the experimental group at the time of repair. Histological and behavioral assessment was carried out at 5 weeks postsurgery.

Results: Experimental transplantation of olfactory ensheathing cells at the time of microsurgical repair of peripheral nerve leads to increased axonal regeneration across the repair site and improved functional outcome.

Conclusions: Olfactory ensheathing cells can integrate and participate in neural repair in both spinal cord and peripheral nerve. They promote axonal sprouting and contribute to remyelination associated with appropriate axon nodal sodium channel clustering necessary for proper impulse conduction. These experimental observations suggest that adjunct cell transplantation with microsurgical repair should be considered as a possible tool in peripheral nerve repair.

No MeSH data available.


Related in: MedlinePlus