Ozawa Hiroshi, Keane Robert W, Marcillo Alexander E, Diaz Paulo H, Dietrich W Dalton
The Miami Project to Cure Paralysis, University of Miami School of Medicine, Miami, Florida 33101, USA.
Exp Neurol. 2002 Sep;177(1):306-13. doi: 10.1006/exnr.2002.7998.
Apoptosis-modulating therapeutics using active-site mimetic peptide ketones (z-VAD-fluoromethylketone (fmk)) have been reported to be efficacious in delaying the apoptotic response in central nervous system lesions. The purpose of the present study was to examine whether the caspase inhibitor z-VAD fmk prevents apoptosis and improves neurological deficit and tissue damage. One-hundred twenty female Sprague-Dawley rats were randomized into groups that were administered 25 microg of z-VAD-fmk or vehicle 30 min and 24 h after moderate spinal cord contusion (NYU impactor, 12.5 mm at T10). Several routes of administration were tested: (1) via Gelfoam placed on the spinal cord, (2) into the cisterna magna via a subarachnoidal catheter, (3) intravenously via the external jugular vein, or (4) intraperitoneally. Another group was injected with 50 microg of zVAD-fmk or vehicle intraperitoneally 30 min, 24, 48, and 72 h after injury. Animals were evaluated for locomotor function (BBB score) at weekly intervals for 6 weeks after injury and treatment. Spinal cords were then processed for histological analysis to determine whether zVAD-fmk treatment decreased contusion volume. Other spinal cord samples were harvested 24 h after injury and examined for cleavage of XIAP by immunoblot analysis. There were no significant differences in the BBB scores, contusion volumes, and XIAP cleavage between animals receiving the broad specific caspase inhibitor by the various routes and animals receiving vehicle alone. These findings raise critical questions about the use of peptide ketone apoptotic inhibitors in improving functional and histopathological outcomes following spinal cord injury.
据报道，使用活性位点模拟肽酮（z-VAD-氟甲基酮（fmk））的凋亡调节疗法在延迟中枢神经系统损伤中的凋亡反应方面是有效的。本研究的目的是检查半胱天冬酶抑制剂z-VAD fmk是否能预防细胞凋亡并改善神经功能缺损和组织损伤。120只雌性Sprague-Dawley大鼠被随机分为几组，在中度脊髓挫伤（纽约大学撞击器，T10处12.5毫米）后30分钟和24小时给予25微克z-VAD-fmk或赋形剂。测试了几种给药途径：（1）通过置于脊髓上的明胶海绵，（2）通过蛛网膜下腔导管注入小脑延髓池，（3）通过颈外静脉静脉内给药，或（4）腹腔内给药。另一组在损伤后30分钟、24、48和72小时腹腔内注射50微克zVAD-fmk或赋形剂。在损伤和治疗后的6周内，每周对动物的运动功能（BBB评分）进行评估。然后对脊髓进行处理以进行组织学分析，以确定zVAD-fmk治疗是否减少了挫伤体积。在损伤后24小时采集其他脊髓样本，并通过免疫印迹分析检查XIAP的裂解情况。通过各种途径接受广泛特异性半胱天冬酶抑制剂的动物与仅接受赋形剂的动物在BBB评分、挫伤体积和XIAP裂解方面没有显著差异。这些发现对肽酮凋亡抑制剂在改善脊髓损伤后的功能和组织病理学结果方面的应用提出了关键问题。
