Apoptosis plays pivotal roles in organ development and tissue homeostasis, with its major function to remove unhealthy cells that may compromise the fitness of the organism. Toll signaling, with the ancient evolutionary origin, regulates embryonic dorsal–ventral patterning, axon targeting and degeneration, and innate immunity. Using Drosophila as a genetic model, we characterized the role of Toll signaling in apoptotic cell death. We found that gain of Toll signaling is able to trigger caspase-dependent cell death in development. In addition, JNK activity is required for Toll-induced cell death. Furthermore, ectopic Toll expression induces the activation of JNK pathway. Moreover, physiological activation of Toll signaling is sufficient to produce JNK-dependent cell death. Finally, Toll signaling activates JNK-mediated cell death through promoting ROS production. As Toll pathway has been evolutionarily conserved from Drosophila to human, this study may shed light on the mechanism of mammalian Toll-like receptors (TLRs) signaling in apoptotic cell death.

中文翻译：

---

Toll 信号促进果蝇 JNK 依赖性细胞凋亡

细胞凋亡在器官发育和组织稳态中起着关键作用，其主要功能是去除可能损害生物体适应性的不健康细胞。Toll 信号具有古老的进化起源，可调节胚胎背腹模式、轴突靶向和退化以及先天免疫。使用果蝇作为遗传模型，我们描述了 Toll 信号在凋亡细胞死亡中的作用。我们发现 Toll 信号的获得能够在发育过程中触发 caspase 依赖性细胞死亡。此外，Toll 诱导的细胞死亡需要 JNK 活性。此外，异位 Toll 表达诱导 JNK 通路的激活。此外，Toll 信号的生理激活足以产生 JNK 依赖性细胞死亡。最后，Toll 信号通过促进 ROS 产生激活 JNK 介导的细胞死亡。由于从果蝇到人类的 Toll 通路在进化上是保守的，这项研究可能会阐明哺乳动物 Toll 样受体 (TLR) 信号传导在凋亡细胞死亡中的机制。