Department of Neurology and Institute of Neurology, First Affiliated Hospital, Center of Neuroscience, Fujian Medical University, 20 Chazhong Road, Fuzhou 350005, China.
Exp Neurol. 2011 Jan;227(1):224-31. doi: 10.1016/j.expneurol.2010.11.009. Epub 2010 Nov 17.
Neuroglobin (Ngb), a newly identified globin in vertebrate brain, has been suggested to be able to protect against brain hypoxic-ischemic injury. However, owing to its large size, the impermeability of the blood-brain barrier (BBB) to Ngb limits its application in brain injury. Recently, the 11-amino-acid human immunodeficiency virus trans-activator of transcription (TAT) protein transduction domain was shown to successfully deliver macromolecules into the brain. This study explored whether the TAT-Ngb fusion protein can cross the BBB and protect the brain from cerebral ischemia. The TAT-Ngb fusion protein generated from Escherichia coli BL21 (DE3) was efficiently delivered into mice brain tissues by intravenous injection as demonstrated by immunohistochemistry and Western blotting. Two groups of mice were treated with filamentous middle cerebral artery occlusion (MCAO) for 30min or 2h followed by reperfusion. Each group was then divided into sub-groups and was injected intravenously with TAT-Ngb, Ngb, or saline respectively before MCAO or immediately after reperfusion. Compared with the Ngb- and saline-treated group, the group with TAT-Ngb treated 2h before MCAO showed significantly less brain infarct volume and had better neurologic outcomes (p<0.05). Furthermore, a TAT-Ngb injection following a 30-min MCAO treatment significantly increased neuronal survival in the striatum (p<0.05). Our results demonstrated that the exogenous Ngb fusion protein containing the TAT protein transduction domain could be efficiently transduced into neurons in the mouse and protect the brain from mild or moderate ischemic injury.
神经球蛋白（Ngb）是脊椎动物脑中新发现的球蛋白，被认为能够保护大脑免受缺氧缺血性损伤。然而，由于其体积较大，血脑屏障（BBB）对 Ngb 的不透性限制了其在脑损伤中的应用。最近，人类免疫缺陷病毒反式激活蛋白（TAT）的 11 个氨基酸蛋白转导结构域被证明可以成功地将大分子递送到大脑中。本研究探讨了 TAT-Ngb 融合蛋白是否可以穿透血脑屏障并保护大脑免受脑缺血。通过免疫组织化学和 Western blot 证实，从大肠杆菌 BL21（DE3）产生的 TAT-Ngb 融合蛋白通过静脉注射有效地递送到小鼠脑组织中。两组小鼠进行大脑中动脉闭塞（MCAO）30min 或 2h 后再灌注。每组再分为亚组，在 MCAO 前或再灌注后立即分别静脉注射 TAT-Ngb、Ngb 或生理盐水。与 Ngb 和生理盐水处理组相比，MCAO 前 2h 给予 TAT-Ngb 处理的组脑梗死体积明显减小，神经功能结局更好（p<0.05）。此外，MCAO 治疗 30min 后给予 TAT-Ngb 注射可显著增加纹状体中的神经元存活（p<0.05）。我们的结果表明，含有 TAT 蛋白转导结构域的外源性 Ngb 融合蛋白可以有效地转导到小鼠神经元中，并保护大脑免受轻度或中度缺血性损伤。
