Department of Medicine, School of Medicine, Medical College, Taipei Medical University, Taipei, Taiwan.
Biochem Pharmacol. 2013 Feb 1;85(3):376-84. doi: 10.1016/j.bcp.2012.11.011. Epub 2012 Nov 23.
Previously, our in vivo studies demonstrated that folic acid (FA) could inhibit angiogenesis and in vitro studies showed that FA reduced vascular endothelial cell proliferation through activating the cSrc/ERK-2/NFκB/p53 pathway mediated by FA receptor (FR). Here, we further examined the effect of FA on endothelial cell migration. Our results showed that FA (10 μM) inhibited the formation of lamellipodia, migration and capillary-like tube formation of human umbilical venous endothelial cells (HUVEC). These inhibition effects induced by FA treatment were not due to reduction of cell survival and cell adhesion on the collagen-coated plate. Treatment of HUVEC with FA (10 μM) increased the activity of cSrc and p190RhoGAP and decreased the activity of RhoA. Over-expression of the constitutively active RhoA construct (RhoA V14) prevented the FA-induced inhibition of migration and capillary-like tube formation in HUVEC. However, these preventive effects were abolished by pretreatment of HUVEC with a ROCK inhibitor, Y27632. Pretreatment with a cSrc inhibitor, PP2, prevented the FA-induced activation of p190GAP, reduction of the RhoA activity and migration inhibition in HUVEC. Moreover, pre-transfection with p190RhoGAP siRNA abolished the FA-induced reduction in the RhoA activity and migration inhibition in HUVEC. Taken together, our results suggest that FA might inhibit endothelial cell migration through inhibiting the RhoA activity mediated by activating the FR/cSrc/p190RhoGAP-signaling pathway. These findings further support the anti-angiogenic activity of FA.
先前，我们的体内研究表明，叶酸（FA）可以抑制血管生成，体外研究表明，FA 通过激活其受体（FR）介导的 cSrc/ERK-2/NFκB/p53 通路来减少血管内皮细胞的增殖。在这里，我们进一步研究了 FA 对内皮细胞迁移的影响。我们的结果表明，FA（10 μM）抑制了人脐静脉内皮细胞（HUVEC）的片状伪足形成、迁移和毛细血管样管形成。FA 处理引起的这些抑制作用不是由于细胞在涂有胶原蛋白的平板上的存活和黏附减少所致。用 FA（10 μM）处理 HUVEC 会增加 cSrc 和 p190RhoGAP 的活性，降低 RhoA 的活性。过表达组成型激活的 RhoA 构建体（RhoA V14）可防止 FA 诱导的 HUVEC 迁移和毛细血管样管形成抑制。然而，用 ROCK 抑制剂 Y27632 预处理 HUVEC 可消除这些预防作用。用 cSrc 抑制剂 PP2 预处理可防止 FA 诱导的 p190GAP 激活、RhoA 活性降低和 HUVEC 迁移抑制。此外，用 p190RhoGAP siRNA 预先转染可消除 FA 诱导的 RhoA 活性降低和 HUVEC 迁移抑制。综上所述，我们的结果表明，FA 可能通过激活 FR/cSrc/p190RhoGAP 信号通路来抑制 RhoA 活性，从而抑制内皮细胞迁移。这些发现进一步支持了 FA 的抗血管生成活性。
