Department of Pharmacology, College of Medicine, University of Illinois, Chicago, USA.
Angiogenesis. 2013 Jan;16(1):15-28. doi: 10.1007/s10456-012-9296-7. Epub 2012 Aug 18.
The 5-hydroxytryptamine type 4 receptor (5-HT(4)R) regulates many physiological processes, including learning and memory, cognition, and gastrointestinal motility. Little is known about its role in angiogenesis. Using mouse hindlimb ischemia model of angiogenesis, we observed a significant reduction of limb blood flow recovery 14 days after ischemia and a decrease in density of CD31-positive vessels in adductor muscles in 5-HT(4)R(-/-) mice compared to wild type littermates. Our in vitro data indicated that 5-HT(4)R endogenously expressed in endothelial cells (ECs) may promote angiogenesis. Inhibition of the receptor with 5-HT(4)R antagonist RS 39604 reduced EC capillary tube formation in the reconstituted basement membrane. Using Boyden chamber migration assay and wound healing "scratch" assay, we demonstrated that RS 39604 treatment significantly suppressed EC migration. Transendothelial resistance measurement and immunofluorescence analysis showed that a 5-HT(4)R agonist RS 67333 led to an increase in endothelial permeability, actin stress fiber and interendothelial gap formation. Importantly, we provided the evidence that 5-HT(4)R-regulated EC migration may be mediated by Gα13 and RhoA. Our results suggest a prominent role of 5-HT(4)R in promoting angiogenesis and identify 5-HT(4)R as a potential therapeutic target for modulating angiogenesis under pathological conditions.
5-羟色胺 4 型受体（5-HT4R）调节许多生理过程，包括学习和记忆、认知和胃肠道动力。它在血管生成中的作用知之甚少。在血管生成的小鼠后肢缺血模型中，我们观察到与野生型同窝仔鼠相比，5-HT4R（-/-）小鼠缺血后 14 天肢体血流恢复明显减少，内收肌中 CD31 阳性血管密度降低。我们的体外数据表明，内皮细胞（ECs）中内源性表达的 5-HT4R 可能促进血管生成。用 5-HT4R 拮抗剂 RS 39604 抑制该受体，可减少再建基底膜中 EC 的毛细血管形成。通过 Boyden 室迁移测定和划痕愈合“划痕”测定，我们证明 RS 39604 处理显著抑制 EC 迁移。跨内皮电阻测量和免疫荧光分析表明，5-HT4R 激动剂 RS 67333 导致内皮通透性增加、肌动蛋白应力纤维和内皮间隙形成。重要的是，我们提供的证据表明，5-HT4R 调节的 EC 迁移可能是由 Gα13 和 RhoA 介导的。我们的结果表明 5-HT4R 在促进血管生成中起重要作用，并确定 5-HT4R 是调节病理条件下血管生成的潜在治疗靶点。
