神经炎症和细胞凋亡是导致蛛网膜下腔出血(SAH)后早期脑损伤(EBI)的两个关键因素,并且与不良预后密切相关。最近,平衡核苷转运蛋白1(ENT1)的出现加速了几种神经系统疾病的炎症和细胞凋亡的严重程度,包括脑缺血,神经变性和癫痫。然而,尚未有研究阐述ENT1在SAH后EBI中的表达水平和作用。
通过血管内穿孔对Sprague-Dawley大鼠进行SAH。在SAH后0.5小时鼻内施用硝基苄硫基肌苷(NBTI)。ENT1、NLRP3、Bcl2、Bax、ACS,Westernblot检测Caspase-1、IL-1。改良的Garcia评分和梁平衡评分用于评估SAH后大鼠的神经功能。此外,苏木精-伊红,然后使用氟玉C和TdT介导的dUTP缺口端标记染色来评估脑组织损伤和神经元凋亡。
分析表明,ENT1的内源性水平在SAH后24小时显著上调,伴有NLRP3炎性体激活和Bcl2下降。NBTI的管理,ENT1抑制剂,剂量为15mg/kg,SAH后24小时和72小时的神经功能缺损和形态学病变均得到改善。此外,ENT1抑制有效地减轻神经元变性和细胞凋亡。此外,15mg/kg的NBTI可观察到增加Bcl2含量并降低Bax水平。此外,抑制ENT1显著降低NLRP3、凋亡相关斑点样蛋白的表达水平,caspase-1和IL-1β。
NBTI部分通过ENT1/NLRP3/Bcl2途径缓解SAH诱导的EBI。
Neuroinflammation and apoptosis are two key factors contributing to early brain injury (EBI) after subarachnoid hemorrhage (SAH) and are strongly associated with a poor prognosis. Recently, equilibrative nucleoside transporter 1 (ENT1) was emerged to accelerate the severity of inflammation and cell apoptosis in several nervous system diseases, including cerebral ischemia, neurodegeneration and epilepsy. However, no study has yet elaborated the expression levels and effects of ENT1 in EBI after SAH.
Sprague-Dawley rats were subjected to SAH by endovascular perforation. Nitrobenzylthioinosine (NBTI) was intranasally administered at 0.5 h after SAH. The protein expression levels of ENT1, NLRP3, Bcl2, Bax, ACS, Caspase-1, IL-1 were detected by western blot. The modified Garcia score and beam balance score were employed to evaluate the neurologic function of rats following SAH. In addition, hematoxylin-eosin, fluoro-jade C and TdT-mediated dUTP nick-end labeling staining were then used to evaluate brain tissue damage and neuronal apoptosis.
Analysis indicated that endogenous levels of ENT1 were significantly upregulated at 24-hour post-SAH, accompanied by NLRP3 inflammasome activation and Bcl2 decline. The administration of NBTI, an inhibitor of ENT1, at a dose of 15 mg/kg, ameliorated neurologic deficits and morphologic lesions at both 24 and 72 h after SAH. Moreover, ENT1 inhibition efficiently mitigated neuronal degeneration and cell apoptosis. In addition, NBTI at 15 mg/kg observably increased Bcl2 content and decreased Bax level. Furthermore, suppression of ENT1 notably reduced the expression levels of NLRP3, apoptosis associated speck like protein containing CARD, caspase-1 and IL-1β.
NBTI relieved SAH-induced EBI partly through ENT1/NLRP3/Bcl2 pathway.