目的:动脉粥样硬化是心血管疾病的主要病理基础。Ferroptosis是细胞死亡的调节形式,由铁驱动的脂质过氧化过程,可以引发和促进动脉粥样硬化。STAT6是一种信号换能器,在调节铁性凋亡中显示出潜在的作用,但是,在动脉粥样硬化形成过程中铁死亡的确切作用尚不清楚。中药麦积痛颗粒(MJT)用于治疗心血管疾病,并显示出潜在的铁凋亡抑制作用。然而,抗动脉粥样硬化作用和潜在机制尚不清楚.在这项研究中,我们确定了STAT6在动脉粥样硬化形成过程中的作用,研究了MJT的抗动脉粥样硬化作用,并确定其抗动脉粥样硬化作用是否依赖于铁性凋亡的抑制。
方法:8周龄雄性LDLR-/-小鼠在第1周和第10周时饲喂高脂饮食(HFD),分别,评估MJT对动脉粥样硬化和铁凋亡的预防和治疗作用。同时,通过评估负责脂质过氧化和铁代谢的基因的表达来确定MJT的抗铁作用和机制。随后,我们重新分析了从STAT6敲低或过表达后的细胞获得的GSE28117的微阵列数据,并分析了STAT6与铁凋亡之间的相关性.最后,给STAT6-/-小鼠喂食HFD并注射AAV-PCSK9,以验证STAT6在动脉粥样硬化形成过程中的铁细胞凋亡中的作用,并揭示MJT的抗动脉粥样硬化和抗铁细胞凋亡作用.
结果:MJT通过减少预防组和治疗组的斑块病变面积和增强斑块稳定性来减轻动脉粥样硬化。MJT通过抑制炎症细胞因子来减轻炎症,并通过降低LDL水平和促进ABCA1/G1介导的脂质流出来抑制泡沫细胞形成。MJT通过减少动脉粥样硬化形成过程中的脂质过氧化和铁失调来改善铁凋亡。机械上,STAT6通过转录抑制SOCS1/p53和DMT1途径负调控铁凋亡。MJT通过刺激STAT6磷酸化抑制DMT1和SOCS1/p53。此外,STAT6基因敲除加剧动脉粥样硬化和铁凋亡,消除了MJT的抗动脉粥样硬化和抗铁作用。
结论:STAT6通过转录抑制DMT1和SOCS1的表达,作为铁凋亡和动脉粥样硬化的负调节因子,MJT通过激活STAT6介导的DMT1和SOCS1/p53通路的抑制,减弱动脉粥样硬化和铁凋亡。这表明STAT6是通过抑制铁凋亡改善动脉粥样硬化的新的有希望的治疗靶点,MJT可以作为动脉粥样硬化治疗的新疗法。
OBJECTIVE: Atherosclerosis is the primary pathological basis of cardiovascular disease. Ferroptosis is a regulated form of cell death, a process of lipid peroxidation driven by iron, which can initiate and promote atherosclerosis. STAT6 is a signal transducer that shows a potential role in regulating ferroptosis, but, the exact role in ferroptosis during atherogenesis remains unclear. The Traditional Chinese Medicine Maijitong granule (
MJT) is used for treating cardiovascular disease and shows a potential inhibitory effect on ferroptosis. However, the antiatherogenic effect and the underlying mechanism remain unclear. In this study, we determined the role of STAT6 in ferroptosis during atherogenesis, investigated the antiatherogenic effect of MJT, and determined whether its antiatherogenic effect was dependent on the inhibition of ferroptosis.
METHODS: 8-week-old male LDLR-/- mice were fed a high-fat diet (HFD) at 1st and 10th week, respectively, to assess the preventive and therapeutic effects of
MJT on atherosclerosis and ferroptosis. Simultaneously, the anti-ferroptotic effects and mechanism of MJT were determined by evaluating the expression of genes responsible for lipid peroxidation and iron metabolism. Subsequently, we reanalyzed microarray data in the GSE28117 obtained from cells after STAT6 knockdown or overexpression and analyzed the correlation between STAT6 and ferroptosis. Finally, the STAT6-/- mice were fed HFD and injected with AAV-PCSK9 to validate the role of STAT6 in ferroptosis during atherogenesis and revealed the antiatherogenic and anti-ferroptotic effect of MJT.
RESULTS: MJT attenuated atherosclerosis by reducing plaque lesion area and enhancing plaque stability in both preventive and therapeutic groups.
MJT reduced inflammation via suppressing inflammatory cytokines and inhibited foam cell formation by lowering the LDL level and promoting ABCA1/G1-mediated lipid efflux. MJT ameliorated the ferroptosis by reducing lipid peroxidation and iron dysregulation during atherogenesis. Mechanistically, STAT6 negatively regulated ferroptosis by transcriptionally suppressing SOCS1/p53 and DMT1 pathways.
MJT suppressed the DMT1 and SOCS1/p53 via stimulating STAT6 phosphorylation. In addition, STAT6 knockout exacerbated atherosclerosis and ferroptosis, which abolished the antiatherogenic and anti-ferroptotic effects of MJT.
CONCLUSIONS: STAT6 acts as a negative regulator of ferroptosis and atherosclerosis via transcriptionally suppressing DMT1 and SOCS1 expression and MJT attenuates atherosclerosis and ferroptosis by activating the STAT6-mediated inhibition of DMT1 and SOCS1/p53 pathways, which indicated that STAT6 acts a novel promising therapeutic target to ameliorate atherosclerosis by inhibiting ferroptosis and MJT can serve as a new therapy for atherosclerosis treatment.