Nestin overexpression precedes caspase-3 upregulation in rats exposed to controlled cortical impact traumatic brain injury.
Nestin overexpression precedes caspase-3 upregulation in rats exposed to controlled cortical impact traumatic brain injury.
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DOI：
10.3727/215517912x639306
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发表时间：
2012
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影响因子：
--
通讯作者：
Borlongan CV
中科院分区：
文献类型：
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作者：
Kaneko Y;Tajiri N;Yu S;Hayashi T;Stahl CE;Bae E;Mestre H;Franzese N;Rodrigues A Jr;Rodrigues MC;Ishikawa H;Shinozuka K;Hethorn W;Weinbren N;Glover LE;Tan J;Achyuta AH;van Loveren H;Sanberg PR;Shivsankar S;Borlongan CV
我们对创伤性脑损伤 (TBI) 的生物学机制和治疗方案的了解是有限的。在这里，我们采用定量实时 PCR (QRT-PCR) 和免疫组织化学分析来确定细胞增殖和凋亡的动态表达，以期为开发 TBI 再生策略的治疗窗口提供见解。为此，使用受控皮质冲击器对年轻成年 Sprague-Dawley 大鼠进行实验性 TBI，然后在 TBI 后 1-48 小时实施安乐死，以进行 QRT-PCR 和免疫组织化学分析。 QRT-PCR 显示，TBI 暴露大鼠的大脑最初表现出巢蛋白 mRNA 表达，早在 TBI 后 1 小时就适度增加，然后在 8 小时显着达到峰值，但此后恢复到 TBI 前的水平。另一方面，Caspase-3 mRNA 表达在 TBI 后 8 小时略有升高，直到 48 小时才显着上调。免疫荧光显微镜显示，TBI 后 24 小时，皮质、胼胝体和室下区的巢蛋白免疫反应细胞显着激增，而活性 caspase-3 免疫反应细胞的数量仅在皮质中发现显着增加，直到 48 小时才发现。这些结果表明，受伤的大脑在 TBI 后立即尝试通过细胞增殖来修复自身，但这种内源性再生机制不足以消除继发性细胞凋亡。在 TBI 急性期开始时，旨在增强细胞增殖和防止细胞凋亡的治疗策略可能会发挥最大益处。
Our understanding of biological mechanisms and treatment options for traumatic brain injury (TBI) is limited. Here, we employed quantitative real-time PCR (QRT-PCR) and immunohistochemical analyses to determine the dynamic expression of cell proliferation and apoptosis in an effort to provide insights into the therapeutic window for developing regenerative strategies for TBI. For this purpose, young adult Sprague-Dawley rats were subjected to experimental TBI using a controlled cortical impactor, then euthanized 1-48 hours after TBI for QRT-PCR and immunohistochemistry. QRT-PCR revealed that brains from TBI exposed rats initially displayed nestin mRNA expression that modestly increased as early as 1-hour post-TBI, then significantly peaked at 8 hours, but thereafter reverted to pre-TBI levels. On the other hand, caspase-3 mRNA expression was slightly elevated at 8 hours post-TBI, which did not become significantly upregulated until 48 hours. Immunofluorescent microscopy revealed a significant surge in nestin immunoreactive cells in the cortex, corpus callosum, and subventricular zone at 24 hours post-TBI, whereas a significant increase in the number of active caspase-3 immunoreactive cells was only found in the cortex and not until 48 hours. These results suggest that the injured brain attempts to repair itself via cell proliferation immediately after TBI, but that this endogenous regenerative mechanism is not sufficient to abrogate the secondary apoptotic cell death. Treatment strategies designed to amplify cell proliferation and to prevent apoptosis are likely to exert maximal benefits when initiated at the acute phase of TBI.