Duan Zhi-Bing, Zheng Ji-Fu, Huang Si-Yue, Hu Li-Li
Department of Nephrology, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, Jiangxi Province, China.
Department of Hematology, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, Jiangxi Province, China.
Kaohsiung J Med Sci. 2024 Nov;40(11):972-984. doi: 10.1002/kjm2.12898. Epub 2024 Oct 10.
Septic acute kidney injury (AKI) is a fatal disease in the intensive care unit, with ferroptosis playing a crucial role in its pathogenesis. Long non-coding RNA (LncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been implicated in septic-induced AKI inflammation and apoptosis. However, its regulatory role in ferroptosis and underlying mechanisms remain unclear. In vivo and in vitro models of septic AKI were established using cecal ligation and puncture (CLP) and lipopolysaccharide (LPS) challenge, respectively. Serum levels of creatinine (Cr), blood urea nitrogen (BUN), kidney injury molecule-1 (Kim-1), neutrophil gelatinase-associated lipocalin (NGAL), and inflammatory cytokine in kidney tissues were determined by ELISA kits. Histopathological alterations and apoptosis were evaluated by HE staining and TUNEL. Ferroptosis was accessed by measuring MDA, GSH, Fe, total and lipid ROS levels, and mitochondrial ultrastructure changes. Target molecular levels were determined using RT-qPCR, Western blotting, and immunofluorescence. Interactions among MALAT1, acyl-CoA synthetase family member 2 (ACSF2) and FUS RNA binding protein (FUS) were validated by RIP and RNA-pull down. MALAT1 level was significantly elevated in both in vivo and in vitro septic AKI models, of which knockdown impeded ferroptosis to alleviate septic AKI. Mechanistically, high MALAT1 expression increased ACSF2 mRNA stability via interaction with FUS. Rescue experiments showed that ACSF2 overexpression partially reversed the ferroptosis inhibition mediated by MALAT1 silencing. MALAT1 induces ferroptosis and exacerbates septic AKI by stabilizing ACSF2 mRNA with the assistance of FUS. These findings provide theoretical evidence for MALAT1 as a potential therapeutic target for septic AKI.
脓毒症急性肾损伤（AKI）是重症监护病房中的一种致命疾病，铁死亡在其发病机制中起关键作用。长链非编码RNA（LncRNA）转移相关肺腺癌转录本1（MALAT1）与脓毒症诱导的AKI炎症和凋亡有关。然而，其在铁死亡中的调节作用及潜在机制仍不清楚。分别采用盲肠结扎和穿刺（CLP）及脂多糖（LPS）刺激建立了脓毒症AKI的体内和体外模型。通过ELISA试剂盒测定血清肌酐（Cr）、血尿素氮（BUN）、肾损伤分子-1（Kim-1）、中性粒细胞明胶酶相关脂质运载蛋白（NGAL）水平以及肾组织中的炎性细胞因子。通过HE染色和TUNEL评估组织病理学改变和凋亡。通过测量丙二醛（MDA）、谷胱甘肽（GSH）、铁、总ROS和脂质ROS水平以及线粒体超微结构变化来评估铁死亡。使用RT-qPCR、蛋白质免疫印迹法和免疫荧光法测定靶分子水平。通过RNA免疫沉淀（RIP）和RNA下拉实验验证了MALAT1、酰基辅酶A合成酶家族成员2（ACSF2）和FUS RNA结合蛋白（FUS）之间的相互作用。在体内和体外脓毒症AKI模型中，MALAT1水平均显著升高，敲低MALAT1可抑制铁死亡以减轻脓毒症AKI。机制上，高表达的MALAT1通过与FUS相互作用增加ACSF2 mRNA的稳定性。挽救实验表明，ACSF2过表达部分逆转了MALAT1沉默介导的铁死亡抑制作用。MALAT1通过在FUS的协助下稳定ACSF2 mRNA来诱导铁死亡并加重脓毒症AKI。这些发现为MALAT1作为脓毒症AKI的潜在治疗靶点提供了理论依据。
