Mitofusin 2 confers the suppression of microglial activation by cannabidiol: Insights from in vitro and in vivo models
Mitofusin 2 confers the suppression of microglial activation by cannabidiol: Insights from in vitro and in vivo models
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DOI：
10.1016/j.bbi.2022.06.003
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发表时间：
2022-06
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影响因子：
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通讯作者：
Mengfan Li;Bingtian Xu;Xing Li;Yueqi Li;S. Qiu;Kechun Chen;Zhuheng Liu;Yuewen Ding;Honghao Wang;Jiangping Xu;Haitao Wang
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文献类型：
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作者：
Mengfan Li;Bingtian Xu;Xing Li;Yueqi Li;S. Qiu;Kechun Chen;Zhuheng Liu;Yuewen Ding;Honghao Wang;Jiangping Xu;Haitao Wang
目前，人们越来越关注大麻二酚（CBD）对炎症反应和免疫系统的调节作用。然而，其机制尚未完全揭示。线粒体融合蛋白2（Mfn 2）是一种参与炎症反应的线粒体融合蛋白。在这里，我们研究了Mfn 2是否具有CBD的抗炎作用。我们发现，CBD治疗降低了脂多糖（LPS）攻击的小胶质细胞中肿瘤坏死因子α、白细胞介素6、诱导型一氧化氮合酶（iNOS）、环氧合酶-2（考克斯-2）和离子化钙结合接头分子-1（Iba 1）的水平。CBD还显著抑制LPS诱导的BV-2细胞活性氧（ROS）的增加和线粒体膜电位的下降。有趣的是，CBD处理增加了Mfn 2的表达，而Mfn 2的敲低则阻断了CBD的作用。相反，Mfn 2的过表达逆转了由Mfn 2小干扰RNA诱导的iNOS、考克斯-2和Iba 1水平的升高。在LPS攻击的小鼠中，我们发现CBD改善了焦虑反应和认知缺陷，增加了Mfn 2的水平，并降低了Iba 1的表达。由于神经炎症和小胶质细胞活化是在多发性硬化症的实验性自身免疫性脑脊髓炎（EAE）模型中观察到的常见事件，我们用CBD治疗EAE小鼠。接受CBD的小鼠表现出临床体征改善，炎症反应减少，髓鞘碱性蛋白水平增加。最重要的是，针对Mfn 2的短发夹RNA的腺相关病毒递送逆转了CBD的保护作用。总之，这些结果表明Mfn 2是赋予CBD抗炎作用的重要免疫调节剂。我们的研究结果还揭示了CBD对包括多发性硬化症在内的炎症性疾病的保护作用的机制。
Currently, there is increasing attention on the regulatory effects of cannabidiol (CBD) on the inflammatory response and the immune system. However, the mechanisms have not yet been completely revealed. Mitofusin 2 (Mfn2) is a mitochondrial fusion protein involved in the inflammatory response. Here, we investigated whether Mfn2 confers the anti-inflammatory effects of CBD. We found that treatment with CBD decreased the levels of tumor necrosis factor α, interleukin 6, inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and ionized calcium-binding adaptor molecule-1 (Iba1) in lipopolysaccharide (LPS)-challenged microglia. CBD also significantly suppressed the increase in reactive oxygen species (ROS) and the decline of mitochondrial membrane potential in BV-2 cells subjected to LPS. Interestingly, CBD treatment increased the expression of Mfn2, while knockdown of Mfn2 blocked the effect of CBD. By contrast, overexpression of Mfn2 reversed the increase in the levels of iNOS, COX-2, and Iba1 induced by Mfn2 small interfering RNA. In mice challenged with LPS, we found that CBD ameliorated the anxiety responses and cognitive deficits, increased the level of Mfn2, and decreased the expression of Iba1. Since neuro-inflammation and microglial activation are the common events that are observed in the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis, we treated EAE mice with CBD. Mice that received CBD showed amelioration of clinical signs, reduced inflammatory response, and increased myelin basic protein level. Most importantly, the adeno-associated virus delivery of short hairpin RNA against Mfn2 reversed the protective effects of CBD. Altogether, these results indicate that Mfn2 is an essential immunomodulator conferring the anti-inflammatory effects of CBD. Our results also shed new light on the mechanisms underlying the protective effects of CBD against inflammatory diseases including multiple sclerosis.