The regenerative response to tissue necrosis

项目摘要 细胞死亡在损伤、疾病或感染后的伤口愈合和再生中具有关键作用。凋亡 在损伤部位，由于死亡细胞产生的信号， 可以引起炎症，增殖，并决定其邻居的生存。因此，这些活动可以 直接调节组织从损伤中恢复的能力例如，在小鼠肝损伤后， 由垂死的肝细胞产生的分子驱动再生增殖。因此，更好地了解如何 组织对损伤信号的反应可能会发现新的治疗干预措施，以改善伤口愈合 和再生。尽管在理解细胞凋亡如何促进 再生，很少有人知道是否非凋亡形式的细胞死亡，如坏死，可能有一个新的机制。 类似的角色。坏死发生在许多人类疾病中，特别是在缺血性损伤（中风和中风）之后。 心脏病发作）、感染和癌症。坏死细胞死亡后的再生明显比 这是由细胞凋亡诱导的，但已在各种组织中记录在案，表明尚未确定和 在每种情况下可能存在不同的机制。因此，这项工作的目的是表征基本的 导致坏死与凋亡后再生的遗传机制。 来自凋亡细胞的信号影响周围组织的证据首先起源于对幼虫的研究。 果蝇的翅原基，一个有吸引力的和强大的模型来研究再生。可用的遗传工具 果蝇中的研究为再生所需的遗传事件提供了重要的见解。研究 幼虫翅膀的再生通常依赖于遗传消融，这是一种有效而稳健的方法， 在组织中诱导空间和时间上受控的细胞死亡。然而，尽管它的优点， 该方法在可以实现的遗传操作方面也受到限制，并且缺乏研究非遗传操作的能力。 凋亡形式的组织损失，如坏死。为了克服这些问题，我们建立了一个新的 方法，双控制，使我们能够诱导坏死或凋亡的发展翅膀原基， 刺激对任何一种损伤的再生反应。我们的初步调查表明，坏死和 细胞凋亡导致周围组织中显著不同的基因表达变化和形态。 然而，重要的是，再生发生在这两种情况下。作为对以前方法的改进，本小说 系统还允许我们针对周围再生组织进行基因操作， 与消融无关。因此，这些实验可以利用大型的专门构建的RNAi 筛选果蝇中可用的文库，以直接询问再生细胞。我们建议使用这个新的 表征导致坏死后成功再生的损伤的遗传反应的方法 与细胞凋亡相比，以期在每种情况下识别再生能力的新调节剂。

PROJECT SUMMARY Cell death has a critical role in wound healing and regeneration following injury, disease or infection. Apoptosis at a site of injury can significantly impact the behavior of surrounding cells, as signals produced by dying cells can induce inflammation, proliferation and dictate the survival of their neighbors. These activities can therefore directly regulate a tissue’s ability to recover from damage. For example, following liver injury in mice, signaling molecules produced by dying hepatocytes drive regenerative proliferation. Thus, a better understanding of how a tissue responds to damage-signals could uncover novel therapeutic interventions to improve wound healing and regeneration. Although advances have been made in understanding how apoptosis contributes to regeneration, little is known about whether non-apoptotic forms of cell death, such as necrosis, might have a similar role. Necrosis occurs in numerous human diseases, particularly following ischemic injury (stroke and heart attack), infections and cancer. Regeneration following necrotic cell death is significantly more variable than that induced by apoptosis, but has been documented in various tissues, suggesting that as yet unidentified and distinct mechanisms might exist in each context. Thus, the aim of this work is to characterize the fundamental genetic mechanisms that lead to regeneration following necrosis versus apoptosis. Evidence that signals from apoptotic cells impact surrounding tissues first originated from studies of the larval wing primordia in Drosophila, an attractive and powerful model to study regeneration. The genetic tools available in Drosophila have led to important insights into the genetic events necessary for regeneration. Studies of regeneration in the larval wing commonly rely on genetic ablation, an efficient and robust approach that permits spatially and temporally controlled cell death to be induced in tissues. However, despite its advantages, this method is also limited in the genetic manipulations that can be achieved, and is lacking the ability to study non- apoptotic forms of tissue loss, such as necrosis. To overcome these problems we have established a new method, DUAL Control, that allows us to induce necrosis or apoptosis in the developing wing primordia, stimulating a regenerative response to either type of damage. Our initial investigations suggest that necrosis and apoptosis lead to dramatically different gene expression changes and morphologies in the surrounding tissue. Importantly, however, regeneration occurs in both situations. As an advance on previous approaches, this novel system also allows us to target genetic manipulations specifically to the surrounding regenerating tissue, independent of ablation. These experiments can therefore take advantage of the large purpose-built RNAi screening libraries available in Drosophila to interrogate regenerating cells directly. We propose to use this new method to characterize the genetic response to damage that leads to successful regeneration following necrosis compared to apoptosis, with a view to identifying novel regulators of regenerative capacity in each context.