Increased vulnerability to focal ischemic brain injury in human apolipoprotein E4 knock-in mice
Increased vulnerability to focal ischemic brain injury in human apolipoprotein E4 knock-in mice
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DOI：
10.1093/jnen/62.3.280
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发表时间：
2003-03-01
影响因子：
3.2
通讯作者：
Asano, T
中科院分区：
文献类型：
--
作者：
Mori, T;Kobayashi, M;Asano, T
越来越多的证据表明，在由人APOE基因编码的3种人载脂蛋白E（apoE）亚型中，ε 4等位基因可能会加重人和动物的脑损伤。本研究旨在比较人apoE对缺血性脑损伤的亚型特异性脆弱性，使用表达人apoE亚型（apoE 2，apoE 3或apoE 4）的小鼠代替小鼠apoE，通过基因靶向技术在胚胎干细胞中产生（敲入，KI）。通过改良的管腔内缝合法使纯合子人apoE 2（2/2）、apoE 3（3/3）或apoE 4（4/4）KI小鼠经受永久性局灶性脑缺血。24小时后，与2/2或3/3 KI小鼠相比，4/4 KI小鼠的脑损伤（根据梗死体积和神经功能缺损估计）显著更差（每次比较p < 0.001），2/2和3/3 KI小鼠之间无显著差异。人apoE表达的免疫组织化学显示apoE分布相似，3系KI小鼠之间的免疫染色强度无显著差异。值得注意的是，在梗死周围区域的神经元和星形胶质细胞中检测到人apoE表达增加，并且在所有缺血KI小鼠的梗死和梗死周围区域之间的边界中明显存在点状表达模式。总之，我们的研究结果表明，apoE影响急性脑损伤的结果在一个亚型特异性的方式（apoE 4> apoE 3 = apoE 2）在基因工程小鼠。
Accumulating evidence suggests that among the 3 human apolipoprotein E (apoE) isoforms encoded by the human APOE gene, the epsilon4 allele may act to exacerbate brain damage in humans and animals. This study aimed to compare the isoform-specific vulnerability conferred by human apoE to ischemic brain damage, using mice expressing human apoE isoforms (apoE2, apoE3, or apoE4) in place of mouse apoE, produced by the gene-targeting technique in embryonic stem cells (knock-in, KI). Homozygous human apoE2 (2/2), apoE3 (3/3), or apoE4 (4/4) KI mice were subjected to permanent focal cerebral ischemia by a modified intraluminal suture method. Twenty-four h thereafter, brain damage, (as estimated by infarct volume and neurologic deficit) was significantly worse in 4/4 KI mice versus 2/2 or 3/3 KI mice (p < 0.001 for each comparison), with no significant differences between 2/2 and 3/3 KI mice. Immunohistochemistry for human apoE expression revealed similar apoE distribution with no significant difference in the immunostaining intensity among the 3 lines of KI mice. Notably, increased expression of human apoE was detected in neurons and astrocytes in the peri-infarct area, and a punctate expression pattern was evident in the border between the infarct and peri-infarct areas in all KI mice subjected to ischemia. Taken together, our results show that apoE affects the outcome of acute brain damage in an isoform-specific fashion (apoE4 > apoE3 = apoE2) in genetically engineered mice.