Hill Caitlin E, Hurtado Andres, Blits Bas, Bahr Ben A, Wood Patrick M, Bartlett Bunge Mary, Oudega Martin
The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
Eur J Neurosci. 2007 Sep;26(6):1433-45. doi: 10.1111/j.1460-9568.2007.05771.x.
Poor survival of cells transplanted into the CNS is a widespread problem and limits their therapeutic potential. Whereas substantial loss of transplanted cells has been described, the extent of acute cell loss has not been quantified previously. To assess the extent and temporal profile of transplanted cell death, and the contributions of necrosis and apoptosis to this cell death following spinal cord injury, different concentrations of Schwann cells (SCs), lentivirally transduced to express green fluorescent protein (GFP), were transplanted into a 1-week-old moderate contusion of the adult rat thoracic spinal cord. In all cases, transplanted cells were present from 10 min to 28 days. There was a 78% reduction in SC number within the first week, with no significant decrease thereafter. Real-time polymerase chain reaction showed a similar 80% reduction in GFP-DNA within the first week, confirming that the decrease in SC number was due to death rather than decreased GFP transgene expression. Cells undergoing necrosis and apoptosis were identified using antibodies against the calpain-mediated fodrin breakdown product and activated caspase 3, respectively, as well as ultrastructurally. Six times more SCs died during the first week after transplantation by necrosis than apoptosis, with the majority of cell death occurring within the first 24 h. The early death of transplanted SCs indicates that factors present, even 1 week after a moderate contusion, are capable of inducing substantial transplanted cell death. Intervention by strategies that limit necrosis and/or apoptosis should be considered for enhancing acute survival of transplanted cells.
移植到中枢神经系统（CNS）的细胞存活率低是一个普遍存在的问题，限制了它们的治疗潜力。虽然已经描述了移植细胞的大量损失，但急性细胞损失的程度此前尚未量化。为了评估移植细胞死亡的程度和时间特征，以及坏死和凋亡对脊髓损伤后这种细胞死亡的贡献，将不同浓度的经慢病毒转导以表达绿色荧光蛋白（GFP）的雪旺细胞（SCs）移植到成年大鼠胸段脊髓1周龄的中度挫伤处。在所有情况下，移植细胞在10分钟至28天内均存在。第一周内SCs数量减少了78%，此后没有显著下降。实时聚合酶链反应显示第一周内GFP-DNA也有类似的80%减少，证实SCs数量的减少是由于死亡而非GFP转基因表达降低。分别使用针对钙蛋白酶介导的血影蛋白降解产物和活化的半胱天冬酶3的抗体以及超微结构鉴定经历坏死和凋亡的细胞。移植后第一周内，因坏死死亡的SCs数量是因凋亡死亡的6倍，且大多数细胞死亡发生在最初的24小时内。移植SCs的早期死亡表明，即使在中度挫伤1周后存在的因素也能够诱导大量移植细胞死亡。应考虑通过限制坏死和/或凋亡的策略进行干预，以提高移植细胞的急性存活率。
