HB-EGF stimulates eNOS expression and nitric oxide production and promotes eNOS dependent angiogenesis
HB-EGF stimulates eNOS expression and nitric oxide production and promotes eNOS dependent angiogenesis
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DOI：
10.1080/08977190802393596
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发表时间：
2008-01-01
期刊：
影响因子：
1.8
通讯作者：
Besner, Gail E.
中科院分区：
文献类型：
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作者：
Mehta, Veela B.;Zhou, Yu;Besner, Gail E.
肝素结合表皮生长因子样生长因子（HB-EGF）是表皮生长因子（EGF）配体家族的成员，由包括内皮细胞在内的许多细胞类型表达。我们以前已经表明，HB-EGF刺激血管生成在体外人脐静脉内皮细胞（HUVEC）。内皮型一氧化氮合酶（eNOS）产生的一氧化氮（NO）是血管生成的重要调节因子。然而，HB-EGF在eNOS调节中的作用尚未研究。HB-EGF诱导的内皮细胞迁移和血管网络形成是否通过eNOS产生NO介导也是未知的。为了解决这些问题，我们用HB-EGF刺激HUVEC，并在mRNA和蛋白水平上评估eNOS的表达。HB-EGF可显著上调内皮细胞eNOS mRNA的表达，促进内皮细胞eNOS蛋白的合成，增加内皮细胞NO的释放。HB-EGF以磷脂酰肌醇3-激酶（PI 3 K）依赖的方式磷酸化eNOS，并刺激体外血管生成。eNOS siRNA在划痕试验中抑制HB-EGF刺激的HUVEC迁移。eNOS的特异性抑制剂NG-硝基-L-精氨酸甲酯（L-NAME）和L-N5-（1-亚氨基乙基）鸟氨酸二盐酸盐（L-NIO）也能阻断HB-EGF诱导的HUVEC迁移和血管生成。更重要的是，我们发现HB-EGF在Marigel Plug测定中也促进体内血管生成。最后，抑制p38 MAPK通路增强HB-EGF诱导的EC迁移和血管生成。我们的结论是，HB-EGF，通过其与EGF受体（EGFR）的相互作用，刺激eNOS激活和NO生产通过PI 3 K依赖性途径。因此，eNOS的激活似乎是HB-EGF介导的血管生成所必需的关键信号通路之一。这些新的发现强调了HB-EGF作为内皮细胞功能调节剂的重要作用。
Heparin-binding EGF-like growth factor (HB-EGF) is a member of the epidermal growth factor (EGF) family of ligands that is expressed by many cell types including endothelial cells. We have previously shown that HB-EGF stimulates angiogenesis in vitro in human umbilical vein endothelial cells (HUVEC). Nitric oxide (NO) derived from endothelial nitric oxide synthase (eNOS) is an important regulator of angiogenesis. However, the role of HB-EGF in regulation of eNOS has not yet been investigated. Whether HB-EGF-induced endothelial cell migration and vascular network formation are mediated via production of NO from eNOS is also unknown. To address these questions, we stimulated HUVEC with HB-EGF and evaluated the expression of eNOS at the mRNA and protein levels. HB-EGF significantly upregulated expression of eNOS mRNA, stimulated eNOS protein production, and increased NO release from HUVEC. HB-EGF phosphorylated eNOS in a phosphatidylinositol 3-kinase (PI3K) dependent fashion, and stimulated in vitro angiogenesis. eNOS siRNA inhibited HB-EGF-stimulated HUVEC migration in a scratch assay. NG-nitro-L-arginine-methyl-ester (L-NAME) and L-N5-(1-lminoethyl)ornithine,dihydochloride (L-NIO) (specific inhibitors of eNOS) also abolished HB-EGF-induced HUVEC migration and angiogenesis. More importantly, we found that HB-EGF also promotes angiogenesis in vivo in the Marigel plug assay. Lastly, inhibition of the p38 MAPK pathway enhanced HB-EGF-induced EC migration and angiogenesis. We conclude that HB-EGF, through its interaction with EGF receptors (EGFR), stimulates eNOS activation and NO production via a PI3K-dependent pathway. Thus, activation of eNOS appears to be one of the key signaling pathways necessary for HB-EGF mediated angiogenesis. These novel findings highlight an important role for HB-EGF as a regulator of endothelial cell function.