Department of Radiology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, Sichuan, China.
Department of Echocardiography & Noninvasive Cardiology Laboratory, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, Sichuan, China.
Exp Neurol. 2024 Sep;379:114868. doi: 10.1016/j.expneurol.2024.114868. Epub 2024 Jun 18.
Ischemic stroke is a disease associated with high morbidity and disability rates; however, its pathogenesis remains elusive, and treatment options are limited. Ferroptosis, an iron-dependent form of cell death, represents a novel avenue for investigation. The objective of this study was to explore the role of melatonin in MCAO-induced ferroptosis and elucidate its underlying molecular mechanism. To simulate brain damage and neuronal injury caused by ischemic stroke, we established a mouse model of MCAO and an HT-22 cell model of OGD/R. The therapeutic efficacy of melatonin was assessed through measurements of infarct size, brain edema, and neurological scores. Additionally, qRT-PCR, WB analysis, and Co-IP assays were employed to investigate the impact of melatonin on ferroptosis markers such as NCOA4 and FTH1 expression levels. Confocal microscopy was utilized to confirm the colocalization between ferritin and lysosomes. Furthermore, we constructed a SIRT6 siRNA model to validate the regulatory effect exerted by SIRT6 on NCOA4 as well as their binding interaction. The present study provides initial evidence that melatonin possesses the ability to mitigate neuronal damage induced by MCAO and OGD/R. Assessment of markers for oxidative damage and ferroptosis revealed that melatonin effectively inhibits intracellular Fe2+ levels, thereby suppressing ferroptosis. Additionally, our findings demonstrate that melatonin modulates the interaction between FTH1 and NCOA4 via SIRT6, influencing ferritin autophagy without affecting cellular macroautophagy. These findings provide reliable data support for the promotion and application of melatonin in clinical practice.
缺血性脑卒中是一种发病率和致残率都很高的疾病；然而，其发病机制仍不清楚，治疗选择有限。铁死亡是一种铁依赖性的细胞死亡形式，代表了一个新的研究方向。本研究旨在探讨褪黑素在 MCAO 诱导的铁死亡中的作用及其潜在的分子机制。为了模拟缺血性脑卒中引起的脑损伤和神经元损伤，我们建立了 MCAO 小鼠模型和 HT-22 细胞 OGD/R 模型。通过测量梗死面积、脑水肿和神经评分来评估褪黑素的治疗效果。此外，还通过 qRT-PCR、WB 分析和 Co-IP 测定来研究褪黑素对铁死亡标志物（如 NCOA4 和 FTH1 表达水平）的影响。通过共聚焦显微镜证实了铁蛋白和溶酶体之间的共定位。此外，我们构建了 SIRT6 siRNA 模型，以验证 SIRT6 对 NCOA4 的调节作用及其结合相互作用。本研究初步证明褪黑素具有减轻 MCAO 和 OGD/R 诱导的神经元损伤的能力。氧化损伤和铁死亡标志物的评估表明，褪黑素能有效抑制细胞内 Fe2+水平，从而抑制铁死亡。此外，我们的研究结果表明，褪黑素通过 SIRT6 调节 FTH1 和 NCOA4 之间的相互作用，影响铁蛋白自噬而不影响细胞巨自噬。这些发现为褪黑素在临床实践中的推广和应用提供了可靠的数据支持。
