Angiogenesis plays an important role in a wide range of physiological processes. In this paper, we designed
and synthesized a series of new analogs including 11 line-peptides and 9 cyclo-peptides by using a marine cyclopeptide
(compound 21) which could stimulate angiogenesis on zebrafish in our previous studies as lead compound. The majority
of compounds synthesized exhibited angiogenic effects when tested in vivo on zebrafish. Among them, compounds 3, 4,
10, and 15 exhibited much stronger angiogenic activities on zebrafish compared with the lead compound, and the line
peptides 3 and 4 showed the most significant angiogenic activities. The SAR (structure-activity relationship) analysis revealed
that Val, Lys and Ala are important for the activity. Further studies showed that 3 could concentration-dependently
stimulate proliferation, migration and invasion in HUVECs (human umbilical vein endothelial cells) in vitro. To explore
the angiogenesis mechanism of this series of compounds, a microarray analysis was carried out to study the gene expression
profile and the result showed that 26 genes were upregulated more than 2 fold changes in treatment with 3 on zebrafish,
in which mmp9 and mmp13a, two angiogenesis-related genes, increased up to 5-folds. Moreover, through the GO
(gene ontology) enrichment analysis, mmp9 and mmp13a genes are the central nodes in the biological processes network.
These results suggested that the pro-angiogenic mechanism of this kind of small molecular peptides is related with the expression
and regulation of mmp genes in the signal transduction pathways. Additionally, one mmp inhibitor was chosen
for further confirmation.
血管生成在多种生理过程中发挥着重要作用。本文以之前研究中能刺激斑马鱼血管生成的海洋环肽(化合物 21)为先导化合物,设计并合成了一系列新的类似物,包括 11 个线肽和 9 个环肽。在对斑马鱼进行体内试验时,合成的大多数化合物都表现出了血管生成作用。其中,与先导化合物相比,化合物 3、4、10 和 15 对斑马鱼表现出更强的血管生成活性,而线肽 3 和 4 则表现出最显著的血管生成活性。
SAR(结构-活性关系)分析表明,Val、Lys 和 Ala 对活性有重要影响。进一步的研究表明,3 能在体外浓度依赖性地刺激 HU
VECs(人脐静脉内皮细胞)的增殖、迁移和侵袭。为了探究这一系列化合物的血管生成机制,研究人员对其
基因表达谱进行了芯片分析,结果表明,用 3 处理斑马鱼时,有 26 个
基因的上调幅度超过 2 倍,其中 mmp9 和 mmp13a 这两个与血管生成相关的
基因的上调幅度高达 5 倍。这些结果表明,这类小分子肽的促血管生成机制与
信号转导通路中 mmp
基因的表达和调控有关。此外,研究人员还选择了一种 mmp
抑制剂进行进一步证实。