基于Keap1/Nrf2信号通路探讨circRNA在慢性间歇低氧肝细胞铁死亡的调控作用及机制

Obstructive sleep apnea hypopnea syndrome (OSAHS) was closely associated with liver injury. However, the specific molecular mechanism remained unclear. Chronic intermittent hypoxia (CIH) is a pathophysiological basis of its associated complications. Study showed that liver injury involved ferroptosis. Our preliminary work found that makers of liver ferroptosis increased and Keap1/Nrf2 antioxidant pathway was dysregulated in liver of CIH-treated rats. RNA sequencing showed that a Keap1/Nrf2 signaling pathway-related circRNA_007549 and circRNA_012807 were highly expressed in liver of CIH-treated rats. We hypothesized that circRNA acted as ceRNA regulating Keap1/Nrf2 pathway via microRNA and induced hepatocyte ferroptosis during CIH-induced liver injury. The study aims to validate the regulatory role of circRNA in CIH-induced hepatocyte ferroptosis by using a CIH model of hepatocyte, overexpressing or silencing circRNA, and rescue experiment. RIP, RNA pull-down, and dual luciferase reporter assays were used to validate the interaction of circRNA with microRNA. These were further verified in animal models. This study provides a better understanding of the regulatory mechanism of CIH-induced hepatocyte ferroptosis. It also provides a potential target for effective treatment of OSAHS-related liver injury.

阻塞性睡眠呼吸暂停低通气综合征（OSAHS）与肝损伤密切相关，但具体分子机制不明确。慢性间歇低氧（CIH）是OSAHS相关并发症的病理生理基础。研究表明肝损伤中存在铁死亡。我们前期研究发现CIH大鼠肝铁死亡指标升高、抗氧化通路Keap1/Nrf2失衡、RNA测序显示CIH大鼠肝Keap1/Nrf2信号通路相关circRNA_007549、012807显著高表达。我们推测在CIH诱导肝损伤中，circRNA作为ceRNA通过microRNA参与调控Keap1/Nrf2通路，致肝细胞铁死亡。本项目拟构建CIH肝细胞模型，过表达沉默circRNA、挽救实验验证circRNA调控CIH肝细胞铁死亡。RIP、RNA pull-down、双荧光素酶报告验证circRNA与microRNA互作。并在动物模型验证。本研究有助于认识CIH肝细胞铁死亡调控机制，以此为靶点可能将有效治疗OSAHS相关肝损伤。

阻塞性睡眠呼吸暂停低通气综合征（OSAHS）与肝损伤密切相关，但具体分子机制不明确。慢性间歇低氧（CIH）是OSAHS相关并发症的病理生理基础。本项目在动物水平发现慢性间歇低氧导致肝损伤过程存在铁死亡；利用代谢组学进一步验证了铁死亡在慢性间歇低氧介导的肝损伤中具有重要的作用。在细胞水平对铁死亡调控机制进行研究，发现Nrf2介导缓解慢性间歇低氧相关肝细胞铁死亡。构建间歇低氧肝细胞损伤模型，发现circRNA差异表达谱并利用qRT-PCR验证结果，生物信息学揭示差异表达circRNA在间歇低氧诱导的肝损伤的功能以及相关调控通路。本研究有助于认识慢性间歇低氧肝损伤的机制，以此为靶点可能将有效治疗OSAHS相关肝损伤。