Liu Ting, Li Lu, Meng Meixia, Gao Ming, Zhang Jinhua, Zhang Yuan, Gan Yukun, Dang Yangjie, Liu Limin
Department of Nephrology, Xi'an People's Hospital (Xi'an Fourth Hospital), Affiliated People's Hospital of Northwest University, Xi'an, Shaanxi 710005, China.
Department of Nephrology, The First Affiliated Hospital of Xi'an Medical University, Xi'an, Shaanxi 710005, China.
Cell Stress Chaperones. 2025 May;30(3):160-171. doi: 10.1016/j.cstres.2025.02.004. Epub 2025 Feb 19.
Acute kidney injury (AKI) is a common and serious complication resulting from ischemia and hypoxia, leading to significant morbidity and mortality. Autophagy, a cellular process for degrading damaged components, plays a crucial role in kidney protection. The unfolded protein response pathway, particularly the inositol-requiring enzyme 1 (IRE1α)/X-box binding protein 1 (XBP1) signaling cascade, is implicated in regulating autophagy during renal stress. To elucidate the role of the IRE1α/XBP1 pathway in autophagy during hypoxia/reoxygenation (H/R) and ischemia/reperfusion (I/R) injury, renal tubular epithelial cells (TECs) were subjected to H/R conditions, and I/R injury was induced in mice. The expression of autophagy-related and endoplasmic reticulum stress markers (IRE1α, XBP1, GRP78, Beclin1, LC3I/II, and P62) was assessed using immunoblotting and immunofluorescence. Additionally, the impacts of IRE1α overexpression and pharmacological agents, IXA6 (IRE1α agonist), and STF083010 (IRE1α inhibitor) were evaluated on autophagy regulation. H/R injury significantly increased mitochondrial damage and the formation of autophagic vesicles in TECs. Key markers of autophagy were elevated in response to H/R and I/R injury, with activation of the IRE1α/XBP1 pathway enhancing autophagic processes. IXA6 treatment improved renal function and reduced injury in I/R models, while STF083010 exacerbated kidney damage. The IRE1α/XBP1 pathway is a critical regulator of autophagy in renal TECs during ischemic stress, suggesting that pharmacological modulation of this pathway may offer therapeutic avenues for preventing or mitigating AKI. Enhanced understanding of these mechanisms may lead to novel strategies for kidney disease management.
急性肾损伤(AKI)是由缺血和缺氧导致的常见且严重的并发症,会引发显著的发病率和死亡率。自噬是一种降解受损成分的细胞过程,在肾脏保护中起着关键作用。未折叠蛋白反应途径,特别是肌醇需求酶1(IRE1α)/X盒结合蛋白1(XBP1)信号级联反应,参与在肾脏应激期间调节自噬。为了阐明IRE1α/XBP1途径在缺氧/复氧(H/R)和缺血/再灌注(I/R)损伤期间自噬中的作用,对肾小管上皮细胞(TECs)进行H/R处理,并在小鼠中诱导I/R损伤。使用免疫印迹和免疫荧光评估自噬相关和内质网应激标志物(IRE1α、XBP1、GRP78、Beclin1、LC3I/II和P62)的表达。此外,评估了IRE1α过表达以及药物IXA6(IRE1α激动剂)和STF083010(IRE1α抑制剂)对自噬调节的影响。H/R损伤显著增加了TECs中的线粒体损伤和自噬泡的形成。自噬的关键标志物在H/R和I/R损伤后升高,IRE1α/XBP1途径的激活增强了自噬过程。IXA6处理改善了I/R模型中的肾功能并减轻了损伤,而STF083010则加剧了肾脏损伤。IRE1α/XBP1途径是缺血应激期间肾TECs自噬的关键调节因子,表明对该途径的药理学调节可能为预防或减轻AKI提供治疗途径。对这些机制的深入了解可能会带来肾脏疾病管理的新策略。