Autophagy regulation of apoptosis and necroptosis within cell populations

细胞死亡中一个重要的未解决的问题是理解为什么群体中的不同细胞在 他们的反应。哪些细胞会存活或死亡，以及在暴露于 死亡刺激？这些问题是基本细胞命运决定的基础，也具有重要的实际意义。 例如，在癌症治疗过程中，当对抗癌药物的非遗传性、异质性反应 药物是最终对治疗产生耐药性的基础。细胞反应中的异源性可以被驱动 通过细胞间稳定的遗传差异，这很容易理解。然而，这种差异也 甚至发生在遗传同质的细胞群体中。这些差异背后的原因是什么？更重要的是， 我们能控制这些效应吗这项资助支持的先前工作发现，即使在一个 在非应激条件下的细胞同质群体中， 自噬通量，这反过来又预测了未来用死亡刺激治疗的结果。后者在 基金期间，我们发现了一种特定的机制，自噬控制凋亡阈值， 这是自噬机制控制坏死性凋亡的一种完全不同的机制。根据这些 在以前的研究中，我们假设：自噬通过调节细胞凋亡和坏死性凋亡阈值， 线粒体外膜透化（MOMP）。这就解释了细胞之间的死亡差异 在人口中。我们将通过使用各种新的方法完成以下目标来测试这一假设。 包括第一种允许光遗传学调节自噬的方法。具体目标1。测试是否 死亡刺激前后的自噬变化控制细胞凋亡反应的异质性 人口具体目标2。确定自噬如何调节坏死性凋亡。通过实现这些目标，我们 将获得新的见解之间的相互作用的两种主要形式的程序性细胞死亡（凋亡和 necroptosis）并揭示自噬如何调节这些过程。

An important unsolved question in cell death is to understand why different cells within a population vary in their responses. Which cells will live or die and what determines exactly how they die after exposure to a death stimulus? These questions underlie fundamental cell fate decisions and also have important practical ramifications, for example, during cancer therapy when non-heritable, heterogeneous responses to anti-cancer drugs underlie the eventual acquisition of resistance to therapy. Heterogeneity in cell responses can be driven by stable genetic differences between cells, which are easy to understand. However, such differences also occur even in genetically homogeneous cell populations. What underlies these differences? More important, can we manipulate these effects? Previous work supported by this grant discovered that even in a homogeneous population of cells under unstressed conditions, there is extensive variation in the amount of autophagic flux, which in turn predicts the outcome to future treatment with a death stimulus. And, in the last funding period, we discovered a specific mechanism by which autophagy controls the apoptosis threshold and a quite different mechanism by which the autophagy machinery can control necroptosis. Building on these previous studies, we hypothesize: autophagy controls apoptotic and necroptotic thresholds by regulating Mitochondrial Outer Membrane Permeabilization (MOMP). And, this explains cell death variation between cells in a population. We will test this hypothesis by completing the following aims using a variety of new approaches including the first method that allows optogenetic regulation of autophagy. Specific Aim 1. Test if autophagy variation before and after a death stimulus controls heterogeneity in apoptosis responses in a cell population. Specific Aim 2. Determine how autophagy regulates necroptosis. By completing these aims, we will gain new insights into the interplay between two major forms of programmed cell death (apoptosis and necroptosis) and uncover how autophagy regulates these processes.