Manáková Sárka, Singh Amanpreet, Kääriäinen Tiina, Taari Heli, Kulkarni Shrinivas K, Männistö Pekka T
Department of Pharmacology and Toxicology, University of Kuopio, Harjulantie 1A, P.O. Box 1627, FIN-70211 Kuopio, Finland.
Brain Res. 2005 Mar 15;1038(1):83-91. doi: 10.1016/j.brainres.2005.01.017.
The mechanism of action of the neurotoxin 6-hydroxydopamine (6-OHDA) is thought to involve the generation of free radicals and subsequent apoptotic processes. We have demonstrated in vitro that the neuroimmunophilin, FK506 (10-100 nM), dose dependently and significantly restored the ROS production to the control level, increased the Bcl-2 protein level, partly inhibited the cytochrome C release from mitochondria and reduced the caspase-3 activation in SH-SY5Y cells. On the other hand, there was no significant restoration of the ATP level by FK506 and the toxin activated proteins, p53 and Bax, were not normalized by FK506. In support of these latter results, daily administration of FK506 for 7 days to rats (0.5, 1 and 3 mg/kg i.p.) did not significantly prevent the apomorphine-induced contralateral circling, measured 2 weeks after unilateral nigral lesioning. Moreover, FK506 pretreatment did not significantly lower the toxin elevated lipid peroxidation levels, indicating that oxidative stress was present even after the FK506 treatment in the lesioned striatum. Taken together, our results with FK506 are inconsistent. We confirm the antioxidant nature of FK506, that is, it blocks ROS production in SH-SY5Y cells. However, there were no significant protective effects in any apoptotic analyses in SH-SY5Y cells and in animal studies, a 7-day FK506 pre-treatment was not able to reverse the toxic effect of 6-OHDA in a rat model of Parkinson's disease.
神经毒素6-羟基多巴胺（6-OHDA）的作用机制被认为涉及自由基的产生及随后的凋亡过程。我们已在体外证明，神经免疫亲和素FK506（10 - 100 nM）剂量依赖性且显著地将活性氧（ROS）产生恢复至对照水平，增加了Bcl-2蛋白水平，部分抑制了细胞色素C从线粒体的释放，并降低了SH-SY5Y细胞中半胱天冬酶-3的激活。另一方面，FK506并未显著恢复ATP水平，且毒素激活的蛋白p53和Bax未被FK506正常化。为支持这些结果，对大鼠每日腹腔注射FK506，持续7天（0.5、1和3mg/kg），在单侧黑质损伤2周后测量，并未显著预防阿扑吗啡诱导的对侧转圈行为。此外，FK506预处理并未显著降低毒素升高的脂质过氧化水平，表明即使在损伤纹状体中进行FK506治疗后仍存在氧化应激。综上所述，我们关于FK506的结果并不一致。我们证实了FK506的抗氧化性质，即它可阻断SH-SY5Y细胞中的ROS产生。然而，在SH-SY5Y细胞的任何凋亡分析中以及在动物研究中均未观察到显著的保护作用，在帕金森病大鼠模型中，7天的FK506预处理无法逆转6-OHDA的毒性作用。
