Taylor J, Gatchalian C L, Keen G, Rubin L L
Eisai London Research Laboratories Ltd, University College London, England.
J Neurochem. 1997 Apr;68(4):1598-605. doi: 10.1046/j.1471-4159.1997.68041598.x.
Proteases of the interleukin-1 beta converting enzyme (ICE) family have been implicated as mediators of apoptosis in several cell types. Here we report the ability of peptide inhibitors of ICE-like proteases to inhibit apoptosis of cultured cerebellar granule neurones caused by reduction of extracellular K+ levels and by the broad-spectrum protein kinase inhibitor staurosporine. Unlike apoptosis induced by K+ deprivation, staurosporine-induced neuronal death does not require new protein synthesis. The ICE-like protease inhibitor benzyloxycarbonyl-Val-Ala-Asp (O-methyl)fluoromethyl ketone (zVAD-fmk) was found to be extremely effective at preventing staurosporine-induced death of cerebellar granule neurones and yet was completely ineffective in preventing K+ deprivation-induced death. Staurosporine induced cleavage of the 116-kDa poly (ADP-ribose) polymerase enzyme, a substrate of ICE-like proteases, to the 85-kDa product, and this cleavage was also blocked by zVAD. By comparison, K+ deprivation led to the disappearance of the 116-kDa protein, with no detectable increase in level of the 85-kDa cleavage product. Taken together, these results imply the existence of divergent ICE-like protease pathways in a CNS model of neuronal apoptosis.
白细胞介素-1β转换酶（ICE）家族的蛋白酶已被认为是几种细胞类型中细胞凋亡的介质。在此我们报告了ICE样蛋白酶的肽抑制剂抑制培养的小脑颗粒神经元凋亡的能力，这些凋亡是由细胞外钾离子水平降低和广谱蛋白激酶抑制剂星形孢菌素引起的。与钾离子剥夺诱导的细胞凋亡不同，星形孢菌素诱导的神经元死亡不需要新的蛋白质合成。发现ICE样蛋白酶抑制剂苄氧羰基-Val-Ala-Asp（O-甲基）氟甲基酮（zVAD-fmk）在预防星形孢菌素诱导的小脑颗粒神经元死亡方面极其有效，但在预防钾离子剥夺诱导的死亡方面则完全无效。星形孢菌素诱导116 kDa的聚（ADP-核糖）聚合酶（一种ICE样蛋白酶的底物）裂解为85 kDa的产物，这种裂解也被zVAD阻断。相比之下，钾离子剥夺导致116 kDa蛋白消失，而85 kDa裂解产物的水平没有可检测到的增加。综上所述，这些结果表明在神经元凋亡的中枢神经系统模型中存在不同的ICE样蛋白酶途径。
