Neuroprotective Effects of Serpina3k in Traumatic Brain Injury
Neuroprotective Effects of Serpina3k in Traumatic Brain Injury
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Serpina3k 在创伤性脑损伤中的神经保护作用
DOI：
10.3389/fneur.2019.01215
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发表时间：
2019-11-15
影响因子：
3.4
通讯作者：
Tian, Hengli
中科院分区：
文献类型：
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作者：
Jing, Yao;Yang, Dianxu;Tian, Hengli
外伤性脑损伤（TBI）是世界范围内致残和死亡的主要原因，部分原因是周围挫伤区域神经元的继发性凋亡。丝氨酸蛋白酶抑制剂Serpina3k在损伤模型中显示出抑制细胞凋亡的作用。在本研究中，我们利用小鼠TBI模型研究了serpina3k的体内抗凋亡功能，并利用SH-SY5Y人神经母细胞瘤细胞系研究了其在体外的潜在神经保护机制。采用控制性皮质冲击法诱导成年雄性C57BL/6小鼠脑外伤。以0.5 mg/kg的浓度静脉滴注Serpina3k蛋白，每天2次，持续14天。将SH-SY5Y细胞进行双轴拉伸损伤，然后用不同浓度的serpina3k处理。我们发现内源性serpina3k蛋白水平在TBI后小鼠脑挫伤周围区域升高。serpina3k处理小鼠的凋亡神经元更少，氧化应激水平更低，神经功能缺损的恢复程度也更高。同时，在SH-SY5Y细胞损伤模型中，最佳浓度（150 nM）的serpina3k抑制了细胞内活性氧的产生，消除了线粒体膜电位的变化，降低了磷酸化-细胞外调节蛋白激酶(p-ERK)/ERK、磷酸化-P38 (p-P38)/P38、B细胞淋巴瘤(Bcl)-2相关X蛋白/Bcl-2、cleaved caspase-3/caspase-3比值，从而降低了细胞凋亡率。这些结果表明serpina3k在TBI后发挥神经保护功能，因此具有治疗潜力。
Traumatic brain injury (TBI) is a major cause of disability and mortality worldwide, in part resulting from secondary apoptosis of neurons in peri-contusion areas. Serpina3k, a serine protease inhibitor, has been shown to inhibit apoptosis in injury models. In this study, we investigated the anti-apoptotic function of serpina3k in vivo using a mouse model of TBI, as well as the underlying neuroprotective mechanism in vitro using the SH-SY5Y human neuroblastoma cell line. TBI was induced in adult male C57BL/6 mice using controlled cortical impact. Serpina3k protein was intravenously administered at a concentration of 0.5 mg/kg twice daily for up to 14 days. SH-SY5Y cells were subjected to biaxial stretch injury and then treated with different concentrations of serpina3k. We found that endogenous serpina3k protein levels were elevated in peri-contusion areas of the mouse brain following TBI. Serpina3k-treated mice had fewer apoptotic neurons, lower levels of oxidative stress, and showed greater recovery of neurological deficits relative to vehicle-treated mice. Meanwhile, in the SH-SY5Y cell injury model, serpina3k at an optimal concentration (150 nM) inhibited the generation of intracellular reactive oxygen species, abrogated changes of the mitochondrial membrane potential, and reduced the phospho-extracellular regulated protein kinases (p-ERK)/ERK, phospho-P38 (p-P38)/P38, B cell lymphoma (Bcl)-2-associated X protein/Bcl-2, and cleaved caspase-3/caspase-3 ratios, thereby reducing the apoptosis rate. These results demonstrate that serpina3k exerts a neuroprotective function following TBI and thus has therapeutic potential.