Purpose

Macrophage apoptosis coupled with a defective phagocytic clearance of the apoptotic cells promotes plaque necrosis in advanced atherosclerosis, which causes acute atherothrombotic vascular disease. Nonsteroidal anti-inflammatory drug sulindac derivative K-80003 treatment was previously reported to dramatically attenuate atherosclerotic plaque progression and destabilization. However, the underlying mechanisms are not fully understood. This study aimed to determine the role of K-80003 on macrophage apoptosis and elucidate the underlying mechanism.

Methods

The mouse model of vulnerable carotid plaque in ApoE^−/− mice was developed in vivo. Consequently, mice were randomly grouped into two study groups: the control group and the K-80003 group (30 mg/kg/day). Samples of carotid arteries were collected to determine atherosclerotic necrotic core area, cellular apoptosis, and oxidative stress. The effects of K-80003 on RAW264.7 macrophage apoptosis, oxidative stress, and autophagic flux were also examined in vitro.

Results

K-80003 significantly suppressed necrotic core formation and inhibited cellular apoptosis of vulnerable plaques. K-80003 can also inhibit 7-ketocholesterol-induced macrophage apoptosis in vitro. Furthermore, K-80003 inhibited intraplaque cellular apoptosis mainly through the suppression of oxidative stress, which is a key cause of advanced lesional macrophage apoptosis. Mechanistically, K-80003 prevented 7-ketocholesterol-induced impairment of autophagic flux in macrophages, evidenced by the decreased LC3II and SQSTM1/p62 expression, GFP-RFP-LC3 cancellation upon K-80003 treatment.

Conclusion

Inhibition of macrophage apoptosis and necrotic core formation by autophagy-mediated reduction of oxidative stress is one mechanism of the suppression of plaque progression and destabilization by K-80003.

中文翻译：

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K-80003 抑制动脉粥样硬化易损斑块中的巨噬细胞凋亡和坏死核心发育

目的

巨噬细胞凋亡加上凋亡细胞的吞噬清除缺陷会促进晚期动脉粥样硬化中的斑块坏死，从而导致急性动脉粥样硬化性血管疾病。此前有报道称，非甾体抗炎药舒林酸衍生物 K-80003 治疗可显着减轻动脉粥样硬化斑块的进展和不稳定。然而，其根本机制尚未完全了解。本研究旨在确定 K-80003 对巨噬细胞凋亡的作用并阐明其潜在机制。

方法

^{ApoE −/−}小鼠的易损颈动脉斑块小鼠模型是在体内开发的。因此，小鼠被随机分为两个研究组：对照组和 K-80003 组（30 毫克/公斤/天）。收集颈动脉样本以确定动脉粥样硬化坏死核心区域、细胞凋亡和氧化应激。还在体外检测了 K-80003 对 RAW264.7 巨噬细胞凋亡、氧化应激和自噬流的影响。

结果

K-80003 显着抑制坏死核心形成并抑制易损斑块的细胞凋亡。K-80003 还可以在体外抑制 7-酮胆固醇诱导的巨噬细胞凋亡。此外，K-80003 主要通过抑制氧化应激来抑制斑内细胞凋亡，氧化应激是晚期病变巨噬细胞凋亡的关键原因。从机制上讲，K-80003 可以防止 7-酮胆固醇诱导的巨噬细胞自噬流受损，K-80003 治疗后 LC3II 和 SQSTM1/p62 表达减少、GFP-RFP-LC3 取消即可证明这一点。

结论

通过自噬介导的氧化应激减少来抑制巨噬细胞凋亡和坏死核心形成是 K-80003 抑制斑块进展和不稳定的机制之一。