Molecular basis of plasma membrane rupture in lytic cell death and its inhibition by cytoprotective agent glycine

裂解细胞死亡中质膜破裂的分子基础及其细胞保护剂甘氨酸的抑制作用

• 批准号: 10713186
• 负责人: Xinghong Dai
• 金额: $ 40.25万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-25 至 2028-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10713186
• 关键词: Apoptotic; Binding; Bone Marrow; Cell Adhesion; Cell Death; Cell membrane; Cells; Cryoelectron Microscopy; Cytoprotection; Cytoprotective Agent; Development; Disease; Event; Glycine; Glycine Agents; Host Defense; Infection; Inflammatory; Inflammatory Response; Light; Link; Lytic; Macrophage; Malignant Neoplasms; Mediating; Membrane; Membrane Proteins; Molecular; Necrosis; Organ Preservation Solutions; Organ Transplantation; Pathologic; Pattern; Play; Process; Proteins; Research; Role; Rupture; Signal Transduction; Stimulus; Structure; Testing; extracellular; new therapeutic target; pathogen; preservation; prevent; tissue injury

PROJECT SUMMARY/ABSTRACT Plasma membrane rupture (PMR) in lytic cell death—including pyroptosis, necroptosis, and post-apoptotic secondary necrosis—is a cataclysmic event that releases large-size intracellular molecules known as damage- associated molecular patterns (DAMPs), which in turn propagate the inflammatory response. Lytic cell death plays an important role in host defense against pathogen infections, but its dysregulation is also implicated in many inflammatory diseases and pathological conditions. PMR was thought to be a passive event, until a recent study identified NINJ1 to be responsible for carrying out this process. NINJ1 is a 16-kDa plasma membrane protein previously identified to be mediating cell adhesion through homotypic binding. It has two transmembrane helices and one extracellular amphipathic helix. NINJ1 undergoes oligomerization to induce PMR, and the amphipathic helix seems to play an important role in this process. However, a highly similar protein NINJ2 in the plasma membrane bearing a similar amphipathic helix does not induce PMR. To understand the molecular basis of NINJ1-oligomerization mediated PMR, we use cryogenic electron microscopy (cryoEM) to study the structures of NINJ1 and NINJ2 oligomers. The progress we have made is shedding light on a mechanistic understanding of this process. However, it also points to more hypotheses that need to be tested in order to fully understand this fundamentally important process. PMR is also linked to glycine cytoprotection in a very recent study. It was demonstrated that glycine treatment prevented NINJ1 oligomerization and thus prevented PMR in bone marrow derived macrophages receiving various forms of lytic cell death stimuli. We will include glycine treatment in our test of hypotheses for the search of signal that triggers NINJ1 oligomerization. This further elucidation of the molecular basis of glycine cytoprotection would inform the development of better cell preservation strategies or agents.

项目概要/摘要 裂解细胞死亡中的质膜破裂 (PMR)，包括细胞焦亡、坏死性凋亡和凋亡后 继发性坏死——是一种灾难性事件，释放出大尺寸的细胞内分子，称为损伤—— 相关分子模式（DAMP），进而传播炎症反应。裂解细胞死亡 在宿主防御病原体感染方面发挥着重要作用，但其失调也与 许多炎症性疾病和病理状况。 PMR 曾被认为是一个被动事件，直到最近的一次 研究确定 NINJ1 负责执行这一过程。 NINJ1 是一种 16 kDa 质膜 先前鉴定为通过同型结合介导细胞粘附的蛋白质。它有两个跨膜 螺旋和一个细胞外两亲性螺旋。 NINJ1 发生寡聚化以诱导 PMR，并且 两亲螺旋似乎在这个过程中发挥着重要作用。然而，在 带有类似两亲螺旋的质膜不会诱导 PMR。了解分子基础 NINJ1寡聚化介导的PMR，我们使用低温电子显微镜（cryoEM）来研究其结构 NINJ1 和 NINJ2 寡聚物。我们所取得的进展揭示了机械理解 这个过程的。然而，它也指出了需要测试更多假设才能充分理解 这个至关重要的过程。最近的一项研究表明，PMR 还与甘氨酸细胞保护有关。原来是 证明甘氨酸治疗可防止 NINJ1 寡聚化，从而防止骨髓中的 PMR 衍生的巨噬细胞接受各种形式的裂解细胞死亡刺激。我们将在我们的治疗中包括甘氨酸处理 寻找触发 NINJ1 寡聚化的信号的假设检验。这进一步阐明了 甘氨酸细胞保护的分子基础将为开发更好的细胞保存策略或 代理。