Variants of Rab GTPase-Effector Binding Protein-2 Cause Variation in the Collateral Circulation and Severity of Stroke.
Variants of Rab GTPase-Effector Binding Protein-2 Cause Variation in the Collateral Circulation and Severity of Stroke.
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DOI：
10.1161/strokeaha.116.014160
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发表时间：
2016-12
期刊：
影响因子：
8.3
通讯作者：
Faber JE
中科院分区：
文献类型：
--
作者：
Lucitti JL;Sealock R;Buckley BK;Zhang H;Xiao L;Dudley AC;Faber JE
侧支血管的范围（数量和直径）差异很大，并且与动脉生成（侧支重塑）一样，是大动脉闭塞后组织损伤严重程度变化的主要决定因素。遗传背景的差异是通过侧枝形成（胚胎侧枝形成）的改变而导致小鼠侧枝范围变化的主要原因。在大脑和其他组织中，不同小鼠品系之间约 80% 的侧支范围变异与 7 号染色体上的某个区域有关。我们最近使用 C57BL/6（B6，高范围）和 BALB/cBy（BC，低范围）小鼠的同源 (CNG) 精细作图将该区域缩小到 737 Kb 基因座 Dce1。在此，我们报告了致病基因。我们使用额外的 CNG 作图和基因敲除小鼠来缩小候选基因的数量。随后的检查发现 Rabep2 内 B6 和 BC 之间存在非同义 SNP (rs33080487)。然后，我们创建了在该位点具有 BC SNP 的 B6 小鼠，以及其他三个品系，用于使用基因编辑预测 Rabep2 的改变或敲除。 rs33080487 引起的单一氨基酸变化解释了 B6 和 BC 小鼠之间由 Dce1 引起的侧支循环范围和梗塞体积的差异。从机制上讲，Rabep2 的变体改变了胚胎发生过程中的胶原蛋白生成，但对体内和体外检查的血管生成没有影响。 Rabep2 缺陷改变了已知参与胶原蛋白生成所需的 VEGF-A→VEGFR2 信号传导的内体运输。 Rabep2 的天然变异是小鼠侧支循环范围和中风严重程度变异的主要决定因素。
The extent (number and diameter) of collateral vessels varies widely and is a major determinant, along with arteriogenesis (collateral remodeling), of variation in severity of tissue injury following large artery occlusion. Differences in genetic background underlie the majority of the variation in collateral extent in mice, through alterations in collaterogenesis (embryonic collateral formation). In brain and other tissues, ~80% of the variation in collateral extent among different mouse strains has been linked to a region on chromosome 7. We recently used congenic (CNG) fine-mapping of C57BL/6 (B6, high extent) and BALB/cBy (BC, low extent) mice to narrow the region to a 737 Kb locus, Dce1. Herein, we report the causal gene. We used additional CNG mapping and knockout mice to narrow the number of candidate genes. Subsequent inspection identified a non-synonymous SNP between B6 and BC within Rabep2 (rs33080487). We then created B6 mice with the BC SNP at this locus plus three other lines for predicted alteration or knockout of Rabep2 using gene editing. The single amino acid change caused by rs33080487 accounted for the difference in collateral extent and infarct volume between B6 and BC mice attributable to Dce1. Mechanistically, variants of Rabep2 altered collaterogenesis during embryogenesis but had no effect on angiogenesis examined in vivo and in vitro. Rabep2 deficiency altered endosome trafficking known to be involved in VEGF-A→VEGFR2 signaling required for collaterogenesis. Naturally occurring variants of Rabep2 are major determinants of variation in collateral extent and stroke severity in mice.