Hattori Tatsuya, Fundora Kevin A, Hamamoto Kouta, Opozda David M, Liang Xinwen, Liu Xiaoming, Zhang Jiawen, Uzun Yasin, Takahashi Yoshinori, Wang Hong-Gang
Division of Pediatric Hematology and Oncology, Department of Pediatrics, The Pennsylvania State University College of Medicine, Hershey, PA, USA.
Department of Pharmacology, The Pennsylvania State University College of Medicine, Hershey, PA, USA.
Autophagy. 2024 Feb;20(2):349-364. doi: 10.1080/15548627.2023.2258701. Epub 2024 Jan 25.
The gene encodes a subunit of the endosomal sorting complex required for transport (ESCRT)-I complex that is frequently lost in a wide variety of human solid cancers. We have previously demonstrated the role of VPS37A in directing the ESCRT membrane scission machinery to seal the phagophore for autophagosome completion. Here, we report that -deficient cells exhibit an accumulation of the apoptotic initiator CASP8 (caspase 8) on the phagophore and are primed to undergo rapid apoptosis through the intracellular death-inducing signaling complex (iDISC)-mediated CASP8 activation upon exposure to endoplasmic reticulum (ER) stress. Using CRISPR-Cas9 gene editing and comparative transcriptome analysis, we identified the ATF4-mediated stress response pathway as a crucial mediator to elicit iDISC-mediated apoptosis following the inhibition of autophagosome closure. Notably, ATF4-mediated iDISC activation occurred independently of the death receptor TNFRSF10B/DR5 upregulation but required the pro-apoptotic transcriptional factor DDIT3/CHOP to enhance the mitochondrial amplification pathway for full-activation of CASP8 in -deficient cells stimulated with ER stress inducers. Our analysis also revealed the upregulation of NFKB/NF-kB signaling as a potential mechanism responsible for restraining iDISC activation and promoting cell survival upon depletion. These findings have important implications for the future development of new strategies to treat human cancers, especially those with loss. ATG: autophagy related; BMS: BMS-345541; CASP: caspase; CHMP: charged multivesicular body protein; DKO: double knockout; Dox: doxycycline; ER: endoplasmic reticulum; ESCRT: endosomal sorting complex required for transport; gRNA: guide RNA; GSEA: gene set enrichment analysis; GSK157: GSK2656157; iDISC: intracellular death-inducing signaling complex; IKK: inhibitor of NFKB kinase; IPA: ingenuity pathway analysis; KO: knockout; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; NFKB/NF-kB: nuclear factor kappa B; OZ: 5Z-7-oxozeaenol; RNA-seq: RNA sequencing; UPR: unfolded protein response; TFT: transcription factor target; THG: thapsigargin; TUN: tunicamycin; VPS: vacuolar protein sorting.
该基因编码转运所需内体分选复合物（ESCRT）-I复合物的一个亚基，该亚基在多种人类实体癌中经常缺失。我们之前已经证明了VPS37A在引导ESCRT膜切割机制以封闭吞噬泡从而完成自噬体形成过程中的作用。在此，我们报告VPS37A缺陷细胞在吞噬泡上显示凋亡起始因子CASP8（半胱天冬酶8）的积累，并且在暴露于内质网（ER）应激时，通过细胞内死亡诱导信号复合物（iDISC）介导的CASP8激活而易于快速发生凋亡。使用CRISPR-Cas9基因编辑和比较转录组分析，我们确定ATF4介导的应激反应途径是在自噬体封闭受到抑制后引发iDISC介导的凋亡的关键介质。值得注意的是，ATF4介导的iDISC激活独立于死亡受体TNFRSF10B/DR5的上调，但需要促凋亡转录因子DDIT3/CHOP来增强线粒体放大途径，以便在受到ER应激诱导剂刺激的VPS37A缺陷细胞中完全激活CASP8。我们的分析还揭示了NFKB/NF-κB信号的上调是在VPS37A缺失时抑制iDISC激活并促进细胞存活的潜在机制。这些发现对于治疗人类癌症，特别是那些具有VPS37A缺失的癌症的新策略的未来发展具有重要意义。ATG：自噬相关；BMS：BMS-345541；CASP：半胱天冬酶；CHMP：带电荷的多泡体蛋白；DKO：双敲除；Dox：强力霉素；ER：内质网；ESCRT：转运所需内体分选复合物；gRNA：引导RNA；GSEA：基因集富集分析；GSK157：GSK2656157；iDISC：细胞内死亡诱导信号复合物；IKK：NFKB激酶抑制剂；IPA： Ingenuity通路分析；KO：敲除；MAP1LC3/LC3：微管相关蛋白1轻链3；NFKB/NF-κB：核因子κB；OZ：5Z-7-氧代玉米烯醇；RNA-seq：RNA测序；UPR：未折叠蛋白反应；TFT：转录因子靶点；THG：毒胡萝卜素；TUN：衣霉素；VPS：液泡蛋白分选
