Sanglifehrin A acts as a potent inhibitor of the mitochondrial permeability transition and reperfusion injury of the heart by binding to cyclophilin-D at a different site from cyclosporin A
Sanglifehrin A acts as a potent inhibitor of the mitochondrial permeability transition and reperfusion injury of the heart by binding to cyclophilin-D at a different site from cyclosporin A
复制标题
DOI：
10.1074/jbc.m202191200
复制
发表时间：
2002-09-20
影响因子：
4.8
通讯作者：
Halestrap, AP
中科院分区：
文献类型：
--
作者：
Clarke, SJ;McStay, GP;Halestrap, AP
环孢菌素A（CsA）通过与亲环素D（CyP-D）结合并抑制其肽基脯氨酰顺反异构酶（PPIase）活性来抑制线粒体通透性转换孔（MPTP）的开放，MPTP是某些形式的坏死性和凋亡性细胞死亡中的关键事件。Sanglifehrin A（SfA），像CsA一样，通过结合亲环素A发挥其免疫抑制作用，但与CsA不同，SfA不抑制钙调磷酸酶活性。在这里，我们表明，SfA抑制PPIase活性的CyP-D（K-0.5 2 nM），并作为一个有效的抑制剂MPTP开放通电和断电条件下。然而，与CsA不同，SfA抑制的剂量-反应曲线是S形而不是双曲线，表明MPTP的多聚体结构在亚基之间具有协同性。此外，SfA并不阻止CyP-D与亚线粒体颗粒或去污剂溶解的腺嘌呤核苷酸移位酶（ANT）结合，这意味着CyP-D与ANT结合不需要PPI酶活性，但孔开放需要。一旦与MPTP结合，SEA就不容易解离，并且在广泛洗涤后保持对孔开放的抑制。为了研究SEA作为体内细胞死亡抑制剂的潜力，我们使用Langendorff灌注的大鼠心脏。SfA引起的MPTP的时间依赖性抑制，维持线粒体分离在更大程度上比CsA抑制。我们证明，SfA，CsA一样，提高了恢复左心室发展的压力在30分钟后的全脑缺血再灌注过程中，大大减少乳酸脱氢酶的释放，这意味着抑制坏死性损伤。因为SfA不抑制钙调磷酸酶活性，我们的数据表明，它可能是更可取的比CsA保护组织从缺血发作恢复和研究的MPTP在细胞死亡中的作用。
Cyclosporin A (CsA) inhibits opening of the mitochondrial permeability transition pore (MPTP), a critical event in some forms of necrotic and apoptotic cell death, by binding to cyclophilin D (CyP-D) and inhibiting its peptidyl-prolyl cis-trans isomerase (PPIase) activity. Sanglifehrin A (SfA), like CsA, exerts its immunosuppressive action by binding to cyclophilin A but at a different site from CsA, and unlike the latter, SfA does not inhibit calcineurin activity. Here we demonstrate that SfA inhibits the PPIase activity of CyP-D (K-0.5 2 nM) and acts as a potent inhibitor of MPTP opening under both energized and de-energized conditions. However, unlike CsA, the dose-response curve for inhibition by SfA, is sigmoidal rather than hyperbolic, suggesting a multimeric structure for the MPTP with cooperativity between subunits. Furthermore, SfA does not prevent CyP-D binding to submitochondrial particles or detergent-solubilized adenine nucleotide translocase (ANT), implying that CyP-D binding to the ANT does not require PPIase activity but pore opening does. Once bound to the MPTP, SEA is not readily dissociated, and inhibition of pore opening is maintained following extensive washing. To investigate the potential of SEA as an inhibitor of cell death in vivo, we used the Langendorff perfused rat heart. SfA caused a time-dependent inhibition of the MPTP that was maintained on mitochondrial isolation to a greater extent than was CsA inhibition. We demonstrate that SfA, like CsA, improves the recovery of left ventricular developed pressure during reperfusion after 30 min of global ischemia and greatly reduces lactate dehydrogenase release, implying inhibition of necrotic damage. Because SfA does not inhibit calcineurin activity, our data suggest that it may be more desirable than CsA for protecting tissues recovering from ischemic episodes and for studying the role of the MPTP in cell death.