El trasplante de células de la glía envolvente del bulbo olfatorio tras lesión de la médula espinal: estudio experimental en ratas / Transplantation of olfactory bulb ensheathing glia after spinal cord injury: experimental study in rats

Objetivo. Evaluar el efecto a largo plazo del trasplante de células de la glía envolvente (GE) del bulbo olfatorio tras lesión de la médula espinal. Material y método. Se practicó una laminectomía dorsal T8, en 16 ratas adultas Sprague-Dawley, dejando al descubierto la médula espinal subyacente, la cual se bañó con rosa de Bengala durante 10 minutos, antes de lesionarla por iluminación con una fibra óptica acoplada a una lámpara halógena, durante 2,5 minutos. A la mitad de los animales se les inyectó 180.000 células de GE, en 10 µl de medio (grupo GE), y a la otra mitad sólo 10 µl de DMEM (Dulbecco's modified Eagle's medium) (grupo DM). Los animales se sacrificaron a los 90 días de efectuar la lesión y se evaluó el área de médula espinal preservada, la recuperación locomotora y la sensibilidad nociceptiva. Resultados. Los animales del grupo GE mostraron un nivel de locomoción superior y retiraron antes la pata al estímulo nociceptivo que los del grupo DM. También hubo una mayor preservación de parénquima medular y más células p75 positivas en el grupo GE que en el DM. Conclusiones. El trasplante de GE favorece la preservación de parénquima medular y evita la pérdida de funciones motoras y sensoriales en la rata

Aim. To evaluate the long-term effect of the transplantation of olfactory bulb ensheathing glia (EG) after spinal cord injury. Materials and methods. Dorsal laminectomy of T8 was performed in 16 adult Sprague-Dawley rats, exposing the underlying spinal cord, which was bathed with Bengala pink for 10 minutes before producing a lesion by fiberoptic focusing of light from a halogen lamp for 2.5 minutes. Half of the animals were injected 180,000 ensheathing glia (EG) in 10 µl of medium (EG group) and half were injected only 10 µl of DMEM (Dulbecco's modified Eagle medium) (DM group). Animals were sacrificed 90 days after injury and the area of spinal cord conserved, locomotor recovery, and nociceptive sensitivity were evaluated. Results. The animals in the EG group showed better locomotion and quicker paw retraction in response to a nociceptive stimulus than the animals in the DM group. More of the spinal parenchyma was preserved and there were more positive p75 cells in the EG group than in the DM group. Conclusions. EG transplantation favored the preservation of spinal parenchyma and prevented the loss of motor and sensorial functions in the rat

Effects of ensheathing cells transplanted into photochemically damaged spinal cord.

Transplantation of olfactory ensheathing cells (OECs) into photochemically damaged rat spinal cord diminished astrocyte reactivity and parenchyma cavitation. The photochemical lesion performed at T12--L1 resulted in severe damage to the spinal cord, so that during the first 15 days postoperation all rats dragged their hindlimbs and did not respond to pinprick. The maximal area and volume of the cystic cavities were lower in transplanted than in non-transplanted rats, not significantly at the T12--L1 lesion site, but significantly at T9--T10 and L4--L6 cord levels. The density of astrocytes in the grey matter was similar at T12--L1 and L4--L6 in non-transplanted and trans- planted rats, but lower in the latter at T9--T10 level. However, in non-transplanted rats all astrocytes showed a hypertrophied appearance, with long and robust processes heavily GFAP-positive, and overexpression of proteoglycan inhibitor of neuritogenesis, whereas in transplanted rats only a few astrocytes showed hypertrophy and the majority had short, thin processes. These results indicate that OECs transplanted into damaged adult rat spinal cord exert a neuroprotective role by reducing astrocytic gliosis and cystic cavitation.