Transplantation of activated transgenic Schwann cells or a fetal spinal cord cell suspension has been widely used to treat spinal cord injury. However, little is known regarding the effects of co-transplantation. In t...Transplantation of activated transgenic Schwann cells or a fetal spinal cord cell suspension has been widely used to treat spinal cord injury. However, little is known regarding the effects of co-transplantation. In the present study, autologous Schwann cells in combination with a fetal spinal cord cell suspension were transplanted into adult Wistar rats with spinal cord injury, and newly generated axonal connections were observed ultrastructurally. Transmission electron microscopic observations showed that the neuroblast first presented cytoplasmic processes, followed by pre- and postsynaptic membranes with low electron density forming a dense projection. The number and types of synaptic vesicles were increased. Synaptic connections developed from single cell body-dendritic synapses into multiple cell body-dendritic and dendrite-dendritic synapses. In addition, the cell organs of the transplanted neuroblast, oligodendroblast and astroblast matured gradually. The blood-brain barrier appeared subsequently. Moreover, neurofilament, histamine, calcitonin-gene-related peptides, and glial fibrillary acidic protein positive fibers were observed in the transplant region. These findings demonstrate that fetal spinal cord cells in the presence of autologous activated Schwann cells can develop into mature synapses in the cavity of injured spinal cords, suggesting the possibility of information exchange through the reconstructed synapse between fetal spinal cord cells and the host.展开更多
Objective: To study the effects of MK-801, an antagonist to N-methyl-D-aspartate (NMDA) receptors, on the apoptosis of spinal cord neurons after cord injury and fend cord transplantation in rats. Methods: Wistar rats ...Objective: To study the effects of MK-801, an antagonist to N-methyl-D-aspartate (NMDA) receptors, on the apoptosis of spinal cord neurons after cord injury and fend cord transplantation in rats. Methods: Wistar rats were random- lzed into group A in which the animals were inflicted with spinal cord hemisection and treated with fetal cord transplantation and MK-801, group B in which the fats were injured with cord hemisection and beated with fend cord transplantation but no MK-80l are given and group C in which the rats received similar cord injury and the eavity in their cord was filled with gelfoam. All the rats were .killed on the lst, 3rd, 7th and 14th day after surgery respectively. The sections of the injured segment of the spinal cord were studied with TUNEL (terminal deoxynucleotidal transferase-mediated DUTP-biotin nick end labeling) and the expression of Bcl-2 was observed with immunohistochemistry. The positive cells were quantitatively analyzed with a computer image analysis system. Results: The Seventy of apoptosis of the cord neurons was in the order of group C > group B > group A (P < 0.005) while the ode of the intensity of Bcl-2 expression was grouP A > group B > group C (P < 0.05). Conclusion: Our findings indicate that fetal cord transplantation and the administration of MK-80l, an antagonist to NMDA receptors can attenuate apoptesis of the cord neurons ther spinal cold injury.展开更多
Fetal cell microchimerism refers to the persistence of fetal cells in the maternal tissues following pregnancy. It has been detected in peripheral organs and the brain, but its existence in the spinal cord has not bee...Fetal cell microchimerism refers to the persistence of fetal cells in the maternal tissues following pregnancy. It has been detected in peripheral organs and the brain, but its existence in the spinal cord has not been reported. Our aim was to detect fetal cell microchimerism in the spinal cord of maternal mice. C57BL/6 female mice were crossed with GFP transgenic male mice and sacrificed after their first or third delivery. GFP-positive cells, which were presumably from fetuses whose fathers were GFP transgenic, were detected in the spinal cord by fluorescence microscopy and immunohistochemistry. PCR was also performed to detect GFP DNA, which must come from GFP hemizygous fetuses. We found GFP-positive cells and detectable GFP DNA in most of the maternal spinal cords. Twenty percent （1/5） of the mice that were only pregnant once had detectable fetal cells, while 80% （4/5） of those that were pregnant three times had detectable fetal cells. Some fetal cells, which not only emitted green fluorescence but also expressed NeuN, were detected in the spinal cords from maternal mice. These results indicate that fetal cells migrate into the spinal cord of a maternal mouse during and/or after the gestational period, and the fetal cells may differentiate into neurons in the spinal cord.展开更多
基金the Tianjin Science and Technology Commission Key Project,No.07JCZDJC08000the Natural Science Foundation of China, No.30772193,30571876National High-Tech R&D Program of China (863 Program),No.2007AA04Z235
文摘Transplantation of activated transgenic Schwann cells or a fetal spinal cord cell suspension has been widely used to treat spinal cord injury. However, little is known regarding the effects of co-transplantation. In the present study, autologous Schwann cells in combination with a fetal spinal cord cell suspension were transplanted into adult Wistar rats with spinal cord injury, and newly generated axonal connections were observed ultrastructurally. Transmission electron microscopic observations showed that the neuroblast first presented cytoplasmic processes, followed by pre- and postsynaptic membranes with low electron density forming a dense projection. The number and types of synaptic vesicles were increased. Synaptic connections developed from single cell body-dendritic synapses into multiple cell body-dendritic and dendrite-dendritic synapses. In addition, the cell organs of the transplanted neuroblast, oligodendroblast and astroblast matured gradually. The blood-brain barrier appeared subsequently. Moreover, neurofilament, histamine, calcitonin-gene-related peptides, and glial fibrillary acidic protein positive fibers were observed in the transplant region. These findings demonstrate that fetal spinal cord cells in the presence of autologous activated Schwann cells can develop into mature synapses in the cavity of injured spinal cords, suggesting the possibility of information exchange through the reconstructed synapse between fetal spinal cord cells and the host.
文摘Objective: To study the effects of MK-801, an antagonist to N-methyl-D-aspartate (NMDA) receptors, on the apoptosis of spinal cord neurons after cord injury and fend cord transplantation in rats. Methods: Wistar rats were random- lzed into group A in which the animals were inflicted with spinal cord hemisection and treated with fetal cord transplantation and MK-801, group B in which the fats were injured with cord hemisection and beated with fend cord transplantation but no MK-80l are given and group C in which the rats received similar cord injury and the eavity in their cord was filled with gelfoam. All the rats were .killed on the lst, 3rd, 7th and 14th day after surgery respectively. The sections of the injured segment of the spinal cord were studied with TUNEL (terminal deoxynucleotidal transferase-mediated DUTP-biotin nick end labeling) and the expression of Bcl-2 was observed with immunohistochemistry. The positive cells were quantitatively analyzed with a computer image analysis system. Results: The Seventy of apoptosis of the cord neurons was in the order of group C > group B > group A (P < 0.005) while the ode of the intensity of Bcl-2 expression was grouP A > group B > group C (P < 0.05). Conclusion: Our findings indicate that fetal cord transplantation and the administration of MK-80l, an antagonist to NMDA receptors can attenuate apoptesis of the cord neurons ther spinal cold injury.
基金supported by the Manitoba Health Research Council(MHRC)the Canadian Institutes for Health Research(CIHR)
文摘Fetal cell microchimerism refers to the persistence of fetal cells in the maternal tissues following pregnancy. It has been detected in peripheral organs and the brain, but its existence in the spinal cord has not been reported. Our aim was to detect fetal cell microchimerism in the spinal cord of maternal mice. C57BL/6 female mice were crossed with GFP transgenic male mice and sacrificed after their first or third delivery. GFP-positive cells, which were presumably from fetuses whose fathers were GFP transgenic, were detected in the spinal cord by fluorescence microscopy and immunohistochemistry. PCR was also performed to detect GFP DNA, which must come from GFP hemizygous fetuses. We found GFP-positive cells and detectable GFP DNA in most of the maternal spinal cords. Twenty percent （1/5） of the mice that were only pregnant once had detectable fetal cells, while 80% （4/5） of those that were pregnant three times had detectable fetal cells. Some fetal cells, which not only emitted green fluorescence but also expressed NeuN, were detected in the spinal cords from maternal mice. These results indicate that fetal cells migrate into the spinal cord of a maternal mouse during and/or after the gestational period, and the fetal cells may differentiate into neurons in the spinal cord.
