Ma Alvin Ch, Lin Rachel, Chan Po-Kwok, Leung Joseph C K, Chan Loretta Y Y, Meng Anming, Verfaillie Catherine M, Liang Raymond, Leung Anskar Y H
Department of Medicine, University of Hong Kong, Hong Kong.
BMC Dev Biol. 2007 May 18;7:50. doi: 10.1186/1471-213X-7-50.
Survivin is the smallest member of the inhibitor of apoptosis (IAP) gene family. Recently, the zebrafish survivin-1 gene has been cloned, showing remarkable sequence identity and similarity over the BIR domain compared with human and mouse survivin gene. Here we investigated the role of survivin in angiogenesis during zebrafish development. Morpholinos (MOs) targeting the 5' untranslated region (UTR) (SurUTR) and sequences flanking the initiation codon (SurATG) of zebrafish survivin-1 gene were injected into embryos at 1-4 cell stage. Vasculature was examined by microangiography and GFP expression in Tg(fli1:EGFP)y1 embryos.
In embryos co-injected with SurUTR and SurATG-MOs, vasculogenesis was intact but angiogenesis was markedly perturbed, especially in the inter-segmental vessels (ISV) and dorsal longitudinal anastomotic vessels (DLAV) of the trunk, the inner optic circle and optic veins of developing eyes and the sub-intestinal vessels. Apoptosis was increased, as shown by TUNEL staining and increase in caspase-3 activity. Efficacy of SurUTR and SurATG-MOs was demonstrated by translation inhibition of co-injected 5'UTR survivin:GFP plasmids. The phenotypes could be recapitulated by splice-site MO targeting the exon2-intron junction of survivin gene and rescued by survivin mRNA. Injection of human vascular endothelial growth factor (VEGF) protein induced ectopic angiogenesis and increased survivin expression, whereas treatment with a VEGF receptor inhibitor markedly reduced angiogenesis and suppressed survivin expression.
Survivin is involved in angiogenesis during zebrafish development and may be under VEGF regulation.
Survivin是凋亡抑制蛋白（IAP）基因家族中最小的成员。最近，斑马鱼survivin-1基因已被克隆，与人类和小鼠survivin基因相比，其在BIR结构域上具有显著的序列同一性和相似性。在此，我们研究了survivin在斑马鱼发育过程中血管生成中的作用。在1-4细胞期将靶向斑马鱼survivin-1基因5'非翻译区（UTR）（SurUTR）和起始密码子侧翼序列（SurATG）的吗啉代寡核苷酸（MOs）注射到胚胎中。通过微血管造影术和Tg(fli1:EGFP)y1胚胎中的绿色荧光蛋白（GFP）表达来检测血管系统。
在共注射SurUTR和SurATG-MO的胚胎中，血管发生正常，但血管生成明显受到干扰，尤其是在躯干的节间血管（ISV）和背侧纵向吻合血管（DLAV）、发育中眼睛的内视圈和视神经静脉以及肠下血管中。TUNEL染色和caspase-3活性增加表明细胞凋亡增加。共注射的5'UTR survivin:GFP质粒的翻译抑制证明了SurUTR和SurATG-MO的有效性。靶向survivin基因外显子2-内含子连接处的剪接位点MO可重现这些表型，而survivin mRNA可挽救这些表型。注射人血管内皮生长因子（VEGF）蛋白可诱导异位血管生成并增加survivin表达，而用VEGF受体抑制剂处理则可显著减少血管生成并抑制survivin表达。
Survivin参与斑马鱼发育过程中的血管生成，可能受VEGF调控。
