Endothelial cell surface F1-Fo ATP synthase is active in ATP synthesis and is inhibited by angiostatin
Endothelial cell surface F1-Fo ATP synthase is active in ATP synthesis and is inhibited by angiostatin
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DOI：
10.1073/pnas.131067798
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发表时间：
2001-06-05
影响因子：
11.1
通讯作者：
Pizzo, SV
中科院分区：
文献类型：
--
作者：
Moser, TL;Kenan, DJ;Pizzo, SV
血管抑制素在体内阻断肿瘤血管生成，几乎可以肯定是通过其阻断内皮细胞迁移和增殖的能力来实现的。尽管血管抑制素的作用机制仍不清楚，但 F-1-F-0 ATP 合酶作为内皮细胞表面主要血管抑制素结合位点的鉴定表明 ATP 代谢可能在血管抑制素反应中发挥作用。先前的研究注意到内皮细胞和某些癌细胞上存在 F-1 ATP 合酶亚基，但并未确定该酶是否在 ATP 合成中发挥作用。我们现在证明 F-1 ATP 合酶催化核心的所有成分都存在于内皮细胞表面，它们共定位成离散的点状结构。双标记 TLC 和生物发光测定表明，表面相关酶在 ATP 合成中具有活性。在基于细胞的生化测定中，该酶的 ATP 合酶和 ATP 酶活性均受到血管抑制素以及针对 ATP 合酶 α 和 β 亚基的抗体的抑制。我们的数据表明，血管抑制素通过抑制内皮表面 ATP 代谢来抑制血管形成，进而可能通过既定机制调节血管生理学。我们现在已经证明，针对 ATP 合酶亚基的抗体表现出与血管抑制素相当的内皮细胞抑制活性，表明这些抗体起到血管抑制素模拟物的作用。
Angiostatin blocks tumor angiogenesis in vivo, almost certainly through its demonstrated ability to block endothelial cell migration and proliferation. Although the mechanism of angiostatin action remains unknown, identification of F-1-F-0 ATP synthase as the major angiostatin-binding site on the endothelial cell surface suggests that ATP metabolism may play a role in the angiostatin response. Previous studies noting the presence of F-1 ATP synthase subunits on endothelial cells and certain cancer cells did not determine whether this enzyme was functional in ATP synthesis. We now demonstrate that all components of the F-1 ATP synthase catalytic core are present on the endothelial cell surface, where they colocalize into discrete punctate structures. The surface-associated enzyme is active in ATP synthesis as shown by dual-label TLC and bioluminescence assays. Both ATP synthase and ATPase activities of the enzyme are inhibited by angiostatin as well as by antibodies directed against the alpha- and beta -subunits of ATP synthase in cell-based and biochemical assays. Our data suggest that angiostatin inhibits vascularization by suppression of endothelial-surface ATP metabolism, which, in turn, may regulate vascular physiology by established mechanisms. We now have shown that antibodies directed against subunits of ATP synthase exhibit endothelial cell-inhibitory activities comparable to that of angiostatin, indicating that these antibodies function as angiostatin mimetics.