Liu Haixiao, Guo Wei, Guo Hao, Zhao Lei, Yue Liang, Li Xia, Feng Dayun, Luo Jianing, Wu Xun, Cui Wenxing, Qu Yan
Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China.
Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, United States.
Front Pharmacol. 2020 May 15;11:712. doi: 10.3389/fphar.2020.00712. eCollection 2020.
Subarachnoid hemorrhage (SAH) is a fatal cerebrovascular condition with complex pathophysiology that reduces brain perfusion and causes cerebral functional impairments. An increasing number of studies indicate that early brain injury (EBI), which occurs within the first 72 h of SAH, plays a crucial role in the poor prognosis of SAH. Bakuchiol (Bak) has been demonstrated to have multiorgan protective effects owing to its antioxidative and anti-inflammatory properties. The present study was designed to investigate the effects of Bak on EBI after SAH and its underlying mechanisms. In this study, 428 adult male C57BL/6J mice weighing 20 to 25 g were observed to investigate the effects of Bak administration in an SAH animal model. The neurological function and brain edema were assessed. Content of MDA/3-NT/8-OHdG/superoxide anion and the activity of SOD and GSH-Px were tested. The function of the blood-brain barrier (BBB) and the protein levels of claudin-5, occludin, zonula occludens-1, and matrix metalloproteinase-9 were observed. TUNEL staining and Fluoro-Jade C staining were conducted to evaluate the death of neurons. Ultrastructural changes of the neurons were observed under the transmission electron microscope. Finally, the roles of Trx, TXNIP, and AMPK in the protective effect of Bak were investigated. The data showed that Bak administration 1) increased the survival rate and alleviated neurological functional deficits; 2) alleviated BBB disruption and brain edema; 3) attenuated oxidative stress by reducing reactive oxygen species, MDA, 3-NT, 8-OHdG, gp91, and 4-HNE; increased the activities of SOD and GSH-Px; and alleviated the damage to the ultrastructure of mitochondria; 4) inhibited cellular apoptosis by regulating the protein levels of Bcl-2, Bax, and cleaved caspase-3; and 5) upregulated the protein levels of Trx1 as well as the phosphorylation of AMPK and downregulated the protein levels of TXNIP. Moreover, the protective effects of Bak were partially reversed by PX-12 and compound C. To summarize, Bak attenuates EBI after SAH by alleviating BBB disruption, oxidative stress, and apoptosis regulating Trx1/TXNIP expression and the phosphorylation of AMPK. Its powerful protective effects might make Bak a promising novel drug for the treatment of EBI after SAH.
蛛网膜下腔出血（SAH）是一种致命的脑血管疾病，其病理生理过程复杂，会减少脑灌注并导致脑功能障碍。越来越多的研究表明，在SAH发生后的最初72小时内出现的早期脑损伤（EBI），在SAH的不良预后中起关键作用。由于其抗氧化和抗炎特性，蛇床子素（Bak）已被证明具有多器官保护作用。本研究旨在探讨Bak对SAH后EBI的影响及其潜在机制。在本研究中，观察了428只体重为20至25克的成年雄性C57BL/6J小鼠，以研究在SAH动物模型中给予Bak的效果。评估了神经功能和脑水肿情况。检测了丙二醛/3-硝基酪氨酸/8-羟基脱氧鸟苷/超氧阴离子的含量以及超氧化物歧化酶和谷胱甘肽过氧化物酶的活性。观察了血脑屏障（BBB）的功能以及紧密连接蛋白-5、闭合蛋白、紧密连接蛋白-1和基质金属蛋白酶-9的蛋白水平。进行了TUNEL染色和荧光玉髓C染色以评估神经元死亡情况。在透射电子显微镜下观察了神经元的超微结构变化。最后，研究了硫氧还蛋白（Trx）、硫氧还蛋白相互作用蛋白（TXNIP）和腺苷酸活化蛋白激酶（AMPK）在Bak保护作用中的作用。数据显示，给予Bak可：1）提高存活率并减轻神经功能缺损；2）减轻BBB破坏和脑水肿；3）通过减少活性氧、丙二醛、3-硝基酪氨酸、8-羟基脱氧鸟苷、糖蛋白91和4-羟基壬烯醛来减轻氧化应激；提高超氧化物歧化酶和谷胱甘肽过氧化物酶的活性；并减轻线粒体超微结构的损伤；4）通过调节Bcl-2、Bax和裂解的半胱天冬酶-3的蛋白水平来抑制细胞凋亡；5）上调硫氧还蛋白-1的蛋白水平以及AMPK的磷酸化水平，并下调TXNIP的蛋白水平。此外，PX-12和化合物C部分逆转了Bak的保护作用。总之，Bak通过减轻BBB破坏、氧化应激和细胞凋亡，调节Trx1/TXNIP表达和AMPK的磷酸化，减轻SAH后的EBI。其强大的保护作用可能使Bak成为治疗SAH后EBI的一种有前景的新型药物。
