Amyloid-β induced membrane damage instigates tunneling nanotube-like conduits by p21-activated kinase dependent actin remodulation
Amyloid-β induced membrane damage instigates tunneling nanotube-like conduits by p21-activated kinase dependent actin remodulation
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DOI：
10.1016/j.bbadis.2021.166246
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发表时间：
2021-08-19
影响因子：
6.2
通讯作者：
Nath, Sangeeta
中科院分区：
文献类型：
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作者：
Dilna, Aysha;Deepak, K., V;Nath, Sangeeta
阿尔茨海默病（AD）病理学通过解剖学上连接的脑区域逐渐进展。已显示淀粉样蛋白β（1-42）寡聚体（oA β）在连接的神经元之间的直接转移，然而，其机制尚未完全揭示。我们观察到的oA β诱导的隧道纳米管（TNT）样的纳米尺度的f-肌动蛋白含有膜导管的形成，在差异分化的SH-SY 5 Y神经元模型。延时图像显示，oA β通过TNT样结构从一个细胞传播到另一个细胞。在TNT样管道形成之前，我们检测到oA β诱导的质膜（PM）损伤和通过溶酶体胞吐作用的钙依赖性修复，随后是大量的内吞作用以重建PM。大量的内吞作用进行监测的膜染色染料TMA-DPH和PM损伤的流入定量碘化丙啶流入的情况下，钙离子。大量的内吞作用最终导致内化的oA β通过肌动蛋白细胞骨架再调节p21激活激酶1（PAK 1）依赖性内吞途径在Lamp 1阳性多泡体/溶酶体中积累。三维定量共聚焦成像、结构照明超分辨显微镜和流式细胞术定量显示，oA β诱导磷酸化PAK 1的激活，磷酸化PAK 1调节细胞之间长拉伸的f-肌动蛋白延伸的形成。此外，通过使用小分子抑制剂IPA-3（一种高度选择性的PAK 1细胞渗透性自动调节抑制剂）阻止oA β的PAK 1依赖性内化来抑制TNT样管道的形成。目前的研究表明，TNT样管道可能是由于oA β诱导的PM损伤和修复过程，随后是PAK 1依赖的内吞作用和肌动蛋白重塑，可能是为了维持细胞表面扩张和/或膜张力平衡。
Alzheimer's disease (AD) pathology progresses gradually via anatomically connected brain regions. Direct transfer of amyloid-beta(1-42) oligomers (oA beta) between connected neurons has been shown, however, the mechanism is not fully revealed. We observed formation of oA beta induced tunneling nanotubes (TNTs)-like nanoscaled f-actin containing membrane conduits, in differentially differentiated SH-SY5Y neuronal models. Time-lapse images showed that oA beta propagate from one cell to another via TNT-like structures. Preceding the formation of TNT-like conduits, we detected oA beta_induced plasma membrane (PM) damage and calcium-dependent repair through lysosomal-exocytosis, followed by massive endocytosis to re-establish the PM. Massive endocytosis was monitored by an influx of the membrane-staining dye TMA-DPH and PM damage was quantified by propidium iodide influx in the absence of Ca2+. The massive endocytosis eventually caused accumulation of internalized oA beta in Lamp1 positive multivesicular bodies/lysosomes via the actin cytoskeleton remodulating p21-activated kinase1 (PAK1) dependent endocytic pathway. Three-dimensional quantitative confocal imaging, structured illumination superresolution microscopy, and flowcytometry quantifications revealed that oA beta induces activation of phospho-PAK1, which modulates the formation of long stretched f-actin extensions between cells. Moreover, the formation of TNT-like conduits was inhibited by preventing PAK1-dependent internalization of oA beta using the small-molecule inhibitor IPA-3, a highly selective cell-permeable auto-regulatory inhibitor of PAK1. The present study reveals that the TNT-like conduits are probably instigated as a consequence of oA beta induced PM damage and repair process, followed by PAK1 dependent endocytosis and actin remodeling, probably to maintain cell surface expansion and/or membrane tension in equilibrium.