Differential astroglial responses in the spinal cord of rats submitted to a sciatic nerve double crush treated with local injection of cultured Schwann cell suspension or lesioned spinal cord extract: implications on cell therapy for nerve repair.
OBJECTIVE
Reactive astrocytes are implicated in several mechanisms after central or peripheral nervous system lesion, including neuroprotection, neuronal sprouting, neurotransmission and neuropathic pain. Schwann cells (SC), a peripheral glia, also react after nerve lesion favoring wound/repair, fiber outgrowth and neuronal regeneration. We investigated herein whether cell therapy for repair of lesioned sciatic nerve may change the pattern of astroglial activation in the spinal cord ventral or dorsal horn of the rat.


METHODS
Injections of a cultured SC suspension or a lesioned spinal cord homogenized extract were made in a reservoir promoted by a contiguous double crush of the rat sciatic nerve. Local injection of phosphate buffered saline (PBS) served as control. One week later, rats were euthanized and spinal cord astrocytes were labeled by immunohistochemistry and quantified by means of quantitative image analysis.


RESULTS
In the ipsilateral ventral horn, slight astroglial activations were seen after PBS or SC injections, however, a substantial activation was achieved after cord extract injection in the sciatic nerve reservoir. Moreover, SC suspension and cord extract injections were able to promote astroglial reaction in the spinal cord dorsal horn bilaterally.


CONCLUSIONS
Spinal cord astrocytes react according to repair processes of axotomized nerve, which may influence the functional outcome. The event should be considered during the neurosurgery strategies.
Dallo
João Gabriel Martins
JG
School of Medicine, USP, São Paulo, Brazil.
Reichert
Bernardo Vergara
BV
Valladão Júnior
José Benedito Ramos
JB
Silva
Camila
C
Luca
Bianca Aparecida de
BA
Levy
Beatriz de Freitas Azevedo
Bde F
Chadi
Gerson
G
D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000502:physiology*; D002478:Cells, Cultured; D007150:Immunohistochemistry; D008297:Male; D009416:Nerve Regeneration / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012583:Schwann Cells / Q000637:transplantation*; D012584:Sciatic Nerve / Q000166:cytology / Q000293:injuries*; D013116:Spinal Cord / Q000737:chemistry; D013119:Spinal Cord Injuries / Q000628:therapy*