Department of Cell Biology and Anatomy, University of South Carolina, School of Medicine, Columbia, South Carolina, USA.
PLoS One. 2013 Aug 5;8(8):e70500. doi: 10.1371/journal.pone.0070500. Print 2013.
Sparstolonin B (SsnB) is a novel bioactive compound isolated from Sparganium stoloniferum, an herb historically used in Traditional Chinese Medicine as an anti-tumor agent. Angiogenesis, the process of new capillary formation from existing blood vessels, is dysregulated in many pathological disorders, including diabetic retinopathy, tumor growth, and atherosclerosis. In functional assays, SsnB inhibited endothelial cell tube formation (Matrigel method) and cell migration (Transwell method) in a dose-dependent manner. Microarray experiments with human umbilical vein endothelial cells (HUVECs) and human coronary artery endothelial cells (HCAECs) demonstrated differential expression of several hundred genes in response to SsnB exposure (916 and 356 genes, respectively, with fold change ≥2, p<0.05, unpaired t-test). Microarray data from both cell types showed significant overlap, including genes associated with cell proliferation and cell cycle. Flow cytometric cell cycle analysis of HUVECs treated with SsnB showed an increase of cells in the G1 phase and a decrease of cells in the S phase. Cyclin E2 (CCNE2) and Cell division cycle 6 (CDC6) are regulatory proteins that control cell cycle progression through the G1/S checkpoint. Both CCNE2 and CDC6 were downregulated in the microarray data. Real Time quantitative PCR confirmed that gene expression of CCNE2 and CDC6 in HUVECs was downregulated after SsnB exposure, to 64% and 35% of controls, respectively. The data suggest that SsnB may exert its anti-angiogenic properties in part by downregulating CCNE2 and CDC6, halting progression through the G1/S checkpoint. In the chick chorioallantoic membrane (CAM) assay, SsnB caused significant reduction in capillary length and branching number relative to the vehicle control group. Overall, SsnB caused a significant reduction in angiogenesis (ANOVA, p<0.05), demonstrating its ex vivo efficacy.
棘孢木酮 B（SsnB）是一种从三棱草中分离得到的新型生物活性化合物，三棱草在传统中药中被用作抗肿瘤药物。血管生成，即新毛细血管从现有血管形成的过程，在许多病理疾病中失调，包括糖尿病视网膜病变、肿瘤生长和动脉粥样硬化。在功能测定中，SsnB 以剂量依赖性方式抑制内皮细胞管形成（Matrigel 法）和细胞迁移（Transwell 法）。人脐静脉内皮细胞（HUVEC）和人冠状动脉内皮细胞（HCAEC）的微阵列实验表明，SsnB 暴露后数百个基因的表达发生差异（分别有 916 个和 356 个基因，倍数变化≥2，p<0.05，未配对 t 检验）。两种细胞类型的微阵列数据显示出显著的重叠，包括与细胞增殖和细胞周期相关的基因。用 SsnB 处理的 HUVEC 的流式细胞术细胞周期分析显示 G1 期细胞增加，S 期细胞减少。细胞周期蛋白 E2（CCNE2）和细胞分裂周期 6（CDC6）是通过 G1/S 检查点控制细胞周期进程的调节蛋白。CCNE2 和 CDC6 在微阵列数据中均下调。实时定量 PCR 证实，SsnB 暴露后 HUVEC 中 CCNE2 和 CDC6 的基因表达分别下调至对照的 64%和 35%。数据表明，SsnB 通过下调 CCNE2 和 CDC6 发挥其抗血管生成特性，阻止 G1/S 检查点的进展。在鸡胚绒毛尿囊膜（CAM）试验中，SsnB 导致与载体对照组相比，毛细血管长度和分支数显著减少。总的来说，SsnB 导致血管生成显著减少（ANOVA，p<0.05），证明了其在体外的疗效。
