Obstructive sleep apnea can worsen the prognosis of subarachnoid hemorrhage.Howeve r,the underlying mechanism remains unclear.In this study,we established a mouse model of subarachnoid hemorrhage using the endovascula...Obstructive sleep apnea can worsen the prognosis of subarachnoid hemorrhage.Howeve r,the underlying mechanism remains unclear.In this study,we established a mouse model of subarachnoid hemorrhage using the endovascular perforation method and exposed the mice to intermittent hypoxia for 8 hours daily for 2 consecutive days to simulate sleep apnea.We found that sleep apnea aggravated brain edema,increased hippocampal neuron apoptosis,and worsened neurological function in this mouse model of subarachnoid hemorrhage.Then,we established an in vitro HT-22 cell model of hemin-induced subarachnoid hemorrhage/intermittent hypoxia and found that the cells died,and lactate dehydrogenase release increased,after 48 hours.We further investigated the underlying mechanism and found that sleep apnea increased the expression of hippocampal neuroinflammatory factors interleukin-1β,interleukin-18,inte rleukin-6,nuclear factorκB,pyro ptosis-related protein caspase-1,pro-caspase-1,and NLRP3,promoted the prolife ration of astrocytes,and increased the expression of hypoxia-inducible factor 1αand apoptosis-associated speck-like protein containing a CARD,which are the key proteins in the hypoxia-inducible factor 1α/apoptosis-associated speck-like protein containing a CARD signaling pathway.We also found that knockdown of hypoxia-inducible factor 1αexpression in vitro greatly reduced the damage to HY22 cells.These findings suggest that sleep apnea aggravates early brain injury after subarachnoid hemorrhage by aggravating neuroinflammation and pyroptosis,at least in part through the hypoxia-inducible factor 1α/apoptosis-associated speck-like protein containing a CARD signaling pathway.展开更多
含NACHT-LRR-PYD结构域蛋白3(NOD-like receptor family pyrin domain-containing protein 3,NLRP3)炎症小体是由NLRP3、凋亡相关斑点样蛋白(apoptosis-associated speck-like protein containing a CARD,ASC)和Caspase-1组装成的多蛋...含NACHT-LRR-PYD结构域蛋白3(NOD-like receptor family pyrin domain-containing protein 3,NLRP3)炎症小体是由NLRP3、凋亡相关斑点样蛋白(apoptosis-associated speck-like protein containing a CARD,ASC)和Caspase-1组装成的多蛋白复合物,能够诱导IL-1β的成熟与分泌,促进炎症反应发生。它的异常活化可导致多种炎症性疾病。已有研究表明,ASC线性泛素化对炎症小体活化至关重要,但是它是否受去泛素化作用调控尚不清楚。课题组最近研究显示,精子发生相关蛋白2(spermatogenesis-associated protein 2,Spata2)与圆柱瘤蛋白(cylindromatosis tumor suppressor protein,CYLD)组成的去泛素化酶复合物通过去泛素化NLRP3炎症小体上游调节蛋白Polo样蛋白激酶4(Polo-like kinases 4,PLK4)抑制炎症小体活化。研究进一步发现,Spata2-CYLD还可去除ASC的线性泛素化,并确定了泛素化位点及其对ASC活化炎症小体功能的重要性。机制研究显示Spata2-CYLD与ASC在细胞中共定位,并且通过NLRP3蛋白结合至炎症小体发挥去泛素化ASC的作用。研究首次鉴定到ASC的去泛素化酶,揭示了Spata2-CYLD调控NLRP3炎症小体活化的又一新机制,为NLRP3炎症小体活化的调控机制提供了新认识。展开更多
基金the Natural Science Foundation of Jiangsu Province(Youth Program),No.BK20190129National Scientific Program of Jiangsu Colleges and Universities of China,No.19KJB320012(both to LY)。
文摘Obstructive sleep apnea can worsen the prognosis of subarachnoid hemorrhage.Howeve r,the underlying mechanism remains unclear.In this study,we established a mouse model of subarachnoid hemorrhage using the endovascular perforation method and exposed the mice to intermittent hypoxia for 8 hours daily for 2 consecutive days to simulate sleep apnea.We found that sleep apnea aggravated brain edema,increased hippocampal neuron apoptosis,and worsened neurological function in this mouse model of subarachnoid hemorrhage.Then,we established an in vitro HT-22 cell model of hemin-induced subarachnoid hemorrhage/intermittent hypoxia and found that the cells died,and lactate dehydrogenase release increased,after 48 hours.We further investigated the underlying mechanism and found that sleep apnea increased the expression of hippocampal neuroinflammatory factors interleukin-1β,interleukin-18,inte rleukin-6,nuclear factorκB,pyro ptosis-related protein caspase-1,pro-caspase-1,and NLRP3,promoted the prolife ration of astrocytes,and increased the expression of hypoxia-inducible factor 1αand apoptosis-associated speck-like protein containing a CARD,which are the key proteins in the hypoxia-inducible factor 1α/apoptosis-associated speck-like protein containing a CARD signaling pathway.We also found that knockdown of hypoxia-inducible factor 1αexpression in vitro greatly reduced the damage to HY22 cells.These findings suggest that sleep apnea aggravates early brain injury after subarachnoid hemorrhage by aggravating neuroinflammation and pyroptosis,at least in part through the hypoxia-inducible factor 1α/apoptosis-associated speck-like protein containing a CARD signaling pathway.
文摘含NACHT-LRR-PYD结构域蛋白3(NOD-like receptor family pyrin domain-containing protein 3,NLRP3)炎症小体是由NLRP3、凋亡相关斑点样蛋白(apoptosis-associated speck-like protein containing a CARD,ASC)和Caspase-1组装成的多蛋白复合物,能够诱导IL-1β的成熟与分泌,促进炎症反应发生。它的异常活化可导致多种炎症性疾病。已有研究表明,ASC线性泛素化对炎症小体活化至关重要,但是它是否受去泛素化作用调控尚不清楚。课题组最近研究显示,精子发生相关蛋白2(spermatogenesis-associated protein 2,Spata2)与圆柱瘤蛋白(cylindromatosis tumor suppressor protein,CYLD)组成的去泛素化酶复合物通过去泛素化NLRP3炎症小体上游调节蛋白Polo样蛋白激酶4(Polo-like kinases 4,PLK4)抑制炎症小体活化。研究进一步发现,Spata2-CYLD还可去除ASC的线性泛素化,并确定了泛素化位点及其对ASC活化炎症小体功能的重要性。机制研究显示Spata2-CYLD与ASC在细胞中共定位,并且通过NLRP3蛋白结合至炎症小体发挥去泛素化ASC的作用。研究首次鉴定到ASC的去泛素化酶,揭示了Spata2-CYLD调控NLRP3炎症小体活化的又一新机制,为NLRP3炎症小体活化的调控机制提供了新认识。
