Institut für Immunologie, Christian-Albrechts-Universität zu Kiel, Michaelisstr. 5, 24105, Kiel, Germany.
Cell Mol Life Sci. 2014 Jan;71(2):331-48. doi: 10.1007/s00018-013-1381-6. Epub 2013 Jun 13.
Programmed necrosis is important in many (patho)physiological settings. For specific therapeutic intervention, however, a better knowledge is required whether necrosis occurs through one single "core program" or through several independent pathways. Previously, the poly(ADP-ribose) polymerase (PARP) pathway has been suggested as a crucial element of tumor necrosis factor (TNF)-mediated necroptosis. Here, we show that TNF-induced necroptosis and the PARP pathway represent distinct and independent routes to programmed necrosis. First, DNA-alkylating agents such as 1-methyl-3-nitro-1-nitrosoguanidine (MNNG) or methyl methanesulfonate rapidly activate the PARP pathway, whereas this is a late and secondary event in TNF-induced necroptosis. Second, inhibition of the PARP pathway does not protect against TNF-induced necroptosis, e.g., the PARP-1 inhibitor 3-AB prevented MNNG- but not TNF-induced adenosine-5'-triposphate depletion, translocation of apoptosis-inducing factor, and necrosis. Likewise, olaparib, a more potent and selective PARP-1 inhibitor failed to block TNF-induced necroptosis, identical to knockdown/knockout of PARP-1, pharmacologic and genetic interference with c-Jun N-terminal kinases and calpain/cathepsin proteases as further components of the PARP pathway. Third, interruption of TNF-induced necroptosis by interference with ceramide generation, RIP1 or RIP3 function or by the radical scavenger butylated hydroxyanisole did not prevent programmed necrosis through the PARP pathway. In summary, our results suggest that the currently established role of the PARP pathway in TNF-induced necroptosis needs to be revised, with consequences for the design of future therapeutic strategies.
程序性细胞坏死在许多（病理）生理环境中都很重要。然而，对于特定的治疗干预，我们需要更好地了解细胞坏死是通过单一的“核心程序”还是通过几个独立的途径发生的。先前，聚（ADP-核糖）聚合酶（PARP）途径已被认为是肿瘤坏死因子（TNF）介导的细胞坏死性凋亡的关键因素。在这里，我们表明 TNF 诱导的细胞坏死性凋亡和 PARP 途径代表了程序性细胞坏死的不同且独立的途径。首先，DNA 烷化剂，如 1-甲基-3-硝基-1-亚硝基胍（MNNG）或甲基甲烷磺酸酯，可迅速激活 PARP 途径，而这是 TNF 诱导的细胞坏死性凋亡中的晚期和次要事件。其次，抑制 PARP 途径并不能防止 TNF 诱导的细胞坏死性凋亡，例如，PARP-1 抑制剂 3-AB 可防止 MNNG 诱导的，但不能防止 TNF 诱导的三磷酸腺苷耗竭、凋亡诱导因子的易位和坏死。同样，奥拉帕尼，一种更有效和选择性的 PARP-1 抑制剂，不能阻断 TNF 诱导的细胞坏死性凋亡，与 PARP-1 的敲降/敲除、c-Jun N 末端激酶和钙蛋白酶/组织蛋白酶蛋白酶的药理学和遗传学干扰作为 PARP 途径的进一步组成部分相同。第三，通过干扰神经酰胺生成、RIP1 或 RIP3 功能或通过自由基清除剂丁基羟基茴香醚来中断 TNF 诱导的细胞坏死性凋亡，不会阻止通过 PARP 途径的程序性细胞坏死。总之，我们的结果表明，PARP 途径在 TNF 诱导的细胞坏死性凋亡中的当前作用需要修正，这对未来治疗策略的设计具有影响。
