Microparticulate Caspase 1 Regulates Gasdermin D and Pulmonary Vascular Endothelial Cell Injury
Microparticulate Caspase 1 Regulates Gasdermin D and Pulmonary Vascular Endothelial Cell Injury
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DOI：
10.1165/rcmb.2017-0393oc
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发表时间：
2018-07-01
影响因子：
6.4
通讯作者：
Sarkar, Anasuya
中科院分区：
文献类型：
--
作者：
Mitra, Srabani;Exline, Matthew;Sarkar, Anasuya
肺内皮细胞凋亡和损伤发生在急性肺损伤/急性呼吸窘迫综合征的所有阶段，并影响疾病进展。半胱天冬酶1、4和5是完成称为焦亡的凋亡程序所必需的，焦亡也涉及促炎细胞因子。由于gasdermin D（GSDMD）介导的pyroptotic死亡，是必不可少的孔形成，我们假设，它可能会直接caspase 1封装的微粒（MP）的释放和介导的内皮细胞死亡。我们目前的工作提供了证据表明，GSDMD是由LPS刺激的THP-1单核细胞释放的，在那里它与活性半胱天冬酶1一起被包装成微粒。此外，只有MP释放刺激的单核细胞，含有裂解的GSDMD和活性半胱天冬酶1诱导内皮细胞凋亡。用半胱天冬酶1抑制剂Y-VAD或泛半胱天冬酶抑制剂Z-VAD预处理的MP不含有裂解的GSDMD。来自半胱天冬酶1敲除细胞的MP也缺乏p30活性GSDMD，进一步证实半胱天冬酶1调节GSDMD功能。尽管对照MP含有裂解的GSDMD而不含半胱天冬酶1，但这些级分不能诱导细胞死亡，表明半胱天冬酶1和GSDMD两者的包封对于细胞死亡诱导是必需的。微粒活性半胱天冬酶1的释放被废除在GSDMD敲除细胞，虽然胞质半胱天冬酶1的激活没有受损。最后，在急性呼吸窘迫综合征脓毒症患者血浆中检测到的微粒GSDMD浓度高于健康供体。两者合计，这些研究结果表明，GSDMD调节释放的微粒活性半胱天冬酶1从单核细胞诱导细胞死亡必不可少的，从而可能在脓毒症诱导的内皮细胞损伤中发挥关键作用。
Lung endothelial cell apoptosis and injury occur throughout all stages of acute lung injury/acute respiratory distress syndrome and impact disease progression. Caspases 1, 4, and 5 are essential for completion of the apoptotic program known as pyroptosis that also involves proinflammatory cytokines. Because gasdermin D (GSDMD) mediates pyroptotic death and is essential for pore formation, we hypothesized that it might direct caspase 1-encapsulated microparticle (MP) release and mediate endothelial cell death. Our present work provides evidence that GSDMD is released by LPS-stimulated THP-1 monocytic cells, where it is packaged into microparticles together with active caspase 1. Furthermore, only MP released from stimulated monocytic cells that contain both cleaved GSDMD and active caspase 1 induce endothelial cell apoptosis. MPs pretreated with caspase 1 inhibitor Y-VAD or pan-caspase inhibitor Z-VAD do not contain cleaved GSDMD. MPs from caspase 1-knockout cells are also deficient in p30 active GSDMD, further confirming that caspase 1 regulates GSDMD function. Although control MPs contained cleaved GSDMD without caspase 1, these fractions were unable to induce cell death, suggesting that encapsulation of both caspase 1 and GSDMD is essential for cell death induction. Release of microparticulate active caspase 1 was abrogated in GSDMD knockout cells, although cytosolic caspase 1 activation was not impaired. Last, higher concentrations of microparticulate GSDMD were detected in the plasma of septic patients with acute respiratory distress syndrome than in that of healthy donors. Taken together, these findings suggest that GSDMD regulates the release of microparticulate active caspase 1 from monocytes essential for induction of cell death and thereby may play a critical role in sepsis-induced endothelial cell injury.