Institute of Cardiovascular Physiology and Pathophysiology at the Walter-Brendel-Centre of Experimental Medicine, Biomedical Center, Ludwig-Maximilians-University, Großhaderner Str. 9, 82152, Planegg, Germany.
Doctoral Programme Clinical Pharmacy, Hospital Pharmacy, University Hospital, LMU Munich, Marchioninistr. 15, 81337, Munich, Germany.
Sci Rep. 2020 Feb 28;10(1):3672. doi: 10.1038/s41598-020-60446-z.
The pro-inflammatory adipokine resistin induces a phenotypic switch of vascular smooth muscle cells (VSMC), a process decisive for atherosclerosis, including morphological changes, increased synthetic activity, proliferation and migration. The guanine-exchange factor ARNO (Cytohesin-2) has been shown to be important for morphological changes and migration of other cell types. In this study we dissected the role of ARNO in resistin induced VSMC phenotypic switching and signalling. Firstly, treatment with the cytohesin inhibitor Secin H3 prevented the resistin mediated induction of morphological changes in VSMC. Secondly, Secin H3 treatment as well as expression of an inactive ARNO (EK) reduced resistin induced VSMC synthetic activity, as assessed by matrix metalloproteinase 2 (MMP-2) expression, as well as the migration into a wound in vitro compared to ARNO WT expression. Thirdly, we found ARNO to influence MMP-2 expression and migration via activation of p38 MAPK and the JNK/AP-1 pathway. Interestingly, these processes were shown to be dependent on the binding of PIP, as mutation of the ARNO PH-domain inhibited VSMC migration, MMP-2 expression as well as p38 MAPK and JNK signalling. Thus, we demonstrate that ARNO is an important link in resistin dependent cell signalling leading to morphological changes, MMP-2 production and migration of VSMC.
促炎脂肪因子抵抗素可诱导血管平滑肌细胞（VSMC）表型转变，这是动脉粥样硬化的关键过程，包括形态变化、合成活性增加、增殖和迁移。鸟嘌呤交换因子 ARNO（Cytohesin-2）已被证明对其他细胞类型的形态变化和迁移很重要。在这项研究中，我们剖析了 ARNO 在抵抗素诱导的 VSMC 表型转换和信号转导中的作用。首先，用细胞松弛素抑制剂 Secin H3 处理可阻止抵抗素介导的 VSMC 形态变化。其次，Secin H3 处理以及表达无活性的 ARNO（EK）可降低抵抗素诱导的 VSMC 合成活性，如基质金属蛋白酶 2（MMP-2）表达以及与 ARNO WT 表达相比在体外划痕中的迁移减少。第三，我们发现 ARNO 通过激活 p38 MAPK 和 JNK/AP-1 通路来影响 MMP-2 表达和迁移。有趣的是，这些过程被证明依赖于 PIP 的结合，因为 ARNO PH 结构域的突变抑制了 VSMC 的迁移、MMP-2 的表达以及 p38 MAPK 和 JNK 信号转导。因此，我们证明 ARNO 是抵抗素依赖性细胞信号转导中导致 VSMC 形态变化、MMP-2 产生和迁移的重要环节。
