Department of Health and Nutrition Biotechnology, Asia University , Taichung, Taiwan.
J Agric Food Chem. 2014 May 7;62(18):4152-8. doi: 10.1021/jf5007165. Epub 2014 Apr 24.
Cell migration plays an important role in angiogenesis and wound repair. Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen that is essential for endothelial cell survival, proliferation, and migration. Docosahexaenoic acid (DHA), an n-3 polyunsaturated fatty acid, shows both anti-inflammatory and antioxidant activities in vitro and in vivo. This study investigated the molecular mechanism by which DHA down-regulates VEGF-induced cell migration. HUVECs were used as the study model, and the MTT assay, Western blot, wound-healing assay, and phosphatase activity assay were used to explore the effects of DHA on cell migration. GPR120 is the putative receptor for DHA action. The results showed that DHA, PD98059 (an ERK1/2 inhibitor), and GW9508 (a GPR120 agonist) inhibited VEGF-induced cell migration. In contrast, pretreatment with okadaic acid (OA, a PP2A inhibitor) and S-nitroso-N-acetyl-DL-penicillamine (an NO donor) reversed the inhibition of cell migration by DHA. VEGF-induced cell migration was accompanied by phosphorylation of ERK1/2 and eNOS. Treatment of HUVECs with DHA increased PP2A enzyme activity and decreased VEGF-induced phosphorylation of ERK1/2 and eNOS. However, pretreatment with OA significantly decreased DHA-induced PP2A enzyme activity and reversed the DHA inhibition of VEGF-induced ERK1/2 and eNOS phosphorylation. These results suggest that stimulation of PP2A activity and inhibition of the VEGF-induced ERK1/2/eNOS signaling pathway may be involved in the DHA suppression of VEGF-induced cell migration. Thus, the effect of DHA on angiogenesis and wound repair is at least partly by virtue of its attenuation of cell migration.
细胞迁移在血管生成和伤口修复中起着重要作用。血管内皮生长因子 (VEGF) 是一种内皮细胞特异性有丝分裂原，对于内皮细胞的存活、增殖和迁移是必不可少的。二十二碳六烯酸 (DHA) 是一种 n-3 多不饱和脂肪酸，在体外和体内均具有抗炎和抗氧化作用。本研究探讨了 DHA 下调 VEGF 诱导的细胞迁移的分子机制。人脐静脉内皮细胞 (HUVEC) 被用作研究模型，通过 MTT 测定、Western blot、划痕愈合测定和磷酸酶活性测定来探讨 DHA 对细胞迁移的影响。GPR120 是 DHA 作用的假定受体。结果表明，DHA、PD98059（ERK1/2 抑制剂）和 GW9508（GPR120 激动剂）抑制了 VEGF 诱导的细胞迁移。相比之下，用 okadaic acid (OA，一种 PP2A 抑制剂) 和 S-nitroso-N-acetyl-DL-penicillamine（一种 NO 供体）预处理可逆转 DHA 对细胞迁移的抑制作用。VEGF 诱导的细胞迁移伴随着 ERK1/2 和 eNOS 的磷酸化。用 DHA 处理 HUVECs 增加了 PP2A 酶活性，并降低了 VEGF 诱导的 ERK1/2 和 eNOS 的磷酸化。然而，OA 的预处理显著降低了 DHA 诱导的 PP2A 酶活性，并逆转了 DHA 对 VEGF 诱导的 ERK1/2 和 eNOS 磷酸化的抑制作用。这些结果表明，刺激 PP2A 活性和抑制 VEGF 诱导的 ERK1/2/eNOS 信号通路可能参与了 DHA 抑制 VEGF 诱导的细胞迁移。因此，DHA 对血管生成和伤口修复的影响至少部分是由于其减弱了细胞迁移。
