Transplantation of preconditioned Schwann cells following hemisection spinal cord injury.
METHODS
Chronically compressed sciatic nerve segments were transplanted to hemisected spinal cord injured rats. Histologic evaluation and behavior functional outcomes were tested after 6 weeks following surgery.


OBJECTIVE
To evaluate the outcome of preconditioned peripheral nerves as a permissive environment in axonal regeneration of the injured spinal cord.


BACKGROUND
Schwann cells have been used to facilitate a permissive environment for the injured spinal cord to regenerate. Previous experiments have shown compressive mechanical stress to be important in stimulating the regenerative behavior of Schwann cells. Transplantation of highly permissive Schwann cell-enriched peripheral nerve grafts may enhance regeneration in spinal cord injury.


METHODS
Adult Sprague-Dawley rats (n = 24) were used to create a hemisection injury of the spinal cord. At 1-week postinjury creation, the spinal cords were reexposed for all animals. Peripheral nerve grafts were obtained from rat sciatic nerve, either untreated or subjected to mechanical compression for 2 weeks with nonconstrictive tubing. Transplantation of grafts was performed after a resection of the glial scar. Functional outcome was measured using the Basso, Beattie, Bresnahan Locomotor Rating Score and footprint analysis. Tract tracing of descending and ascending spinal cord tracts was performed at 6 weeks after surgery for histologic evaluation of axonal regeneration.


RESULTS
Preconditioned transplants had significantly higher Basso, Beattie, Bresnahan Scores versus hemisection alone in the late postoperative period (P < 0.05). They also had significantly less foot exorotation and base of support when compared to nonconditioned transplants. Histologic analysis showed increased regeneration at lesional sites for preconditioned transplants versus control group (P < 0.05).


CONCLUSIONS
Functional recovery after hemisection injury improved significantly in the late postoperative period with transplantation of preconditioned peripheral nerve. Preconditioned grafts also exhibit sustained axonal regeneration at and past the lesional site in histologic analysis. Further investigation with later time points is warranted.
Dinh
Paul
P
University of California, Irvine, CA, USA.
Bhatia
Nitin
N
Rasouli
Alexandre
A
Suryadevara
Sourabh
S
Cahill
Kim
K
Gupta
Ranjan
R
D000818:Animals; D017690:Cell Transplantation / Q000379:methods*; D005260:Female; D008124:Locomotion / Q000502:physiology; D008866:Microsurgery / Q000379:methods; D023421:Models, Animal; D009416:Nerve Regeneration / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012583:Schwann Cells / Q000166:cytology / Q000637:transplantation*; D012584:Sciatic Nerve / Q000637:transplantation*; D013116:Spinal Cord / Q000473:pathology / Q000601:surgery; D013119:Spinal Cord Injuries / Q000503:physiopathology / Q000601:surgery*