Objectives: To observe the effect of electro-scalp acupuncture (ESA) on the expression of cytochrome P450a1/b1 (CYP27a1/b1), cytochrome P45024a (CYP24a), signal transducer and activator of transcription (STAT)4, STAT6, tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-4 in ischemic cerebral cortex of rats with acute ischemic stroke, so as to explore its mechanism in alleviating inflammatory reaction of ischemic stroke.
Methods: Sixty SD rats were randomly divided into sham-operation, model, vitamin D3 and ESA groups, with 15 rats in each group. The middle cerebral artery occlusion rat model was established with thread ligation according to Zea-Longa's method. Rats in the vitamin D3 group were given 1, 25-VitD3 solution (3 ng·100 g-1·d-1) by gavage, once daily for 7 days. Rats in the ESA group were treated at bilateral anterior parietotemporal slash (MS6) with ESA (2 Hz/100 Hz, 1 mA), 30 min a day for 7 days. Before and after interventions, the neurological deficit score and neurobehavioral score were evaluated. TTC staining was used to detect the volume of cerebral infarction in rats. The positive expressions of CYP24a, CYP27a1 and CYP27b1 in the cerebral cortex of ischemic area were detected by immunofluorescence. The mRNA expressions of STAT4 and STAT6 in the cerebral cortex of ischemic area were detected by quantitative real-time PCR. The protein expression levels of TNF-α, IL-1β and IL-4 in the cerebral cortex of ischemic area were detected by Western blot.
Results: Compared with the sham-operation group, the neurological deficit score, neurobehavioral score, the percentage of cerebral infarction volume, the positive expression level of CYP24a and mRNA expression level of STAT4, protein expression levels of TNF-α and IL-1β in cerebral cortex were increased (P<0.01), while the positive expression levels of CYP27a1/b1 and STAT6 mRNA, protein expression level of IL-4 were decreased (P<0.01) in the model group. After the treatment and compared with the model group, the neurological deficit score, neurobehavioral score, the percentage of cerebral infarction volume, the positive expression level of CYP24a and mRNA expression level of STAT4, protein expression levels of TNF-α and IL-1β in cerebral cortex were decreased (P<0.01), while the positive expression levels of CYP27a1/b1 and STAT6 mRNA expression level, protein expression level of IL-4 were increased (P<0.01) in the ESA and vitamin D3 groups.
Conclusions: ESA can alleviate the inflammatory response in ischemic stroke, which maybe related to its function in regulating the balance between CYP27a1/b1 and CYP24a, converting vitamin D into active vitamin D3, inhibiting vitamin D3 degradation, and regulating Th1/Th2 balance.
目的: 观察电头针对急性缺血性脑卒中大鼠缺血大脑皮层区细胞色素P450a1/b1（CYP27a1/b1）、细胞色素P45024a（CYP24a）、信号转导和转录激活因子（STAT）4、STAT6及肿瘤坏死因子α（TNF-α）、白细胞介素（IL）-1β、IL-4表达的影响，探讨电头针缓解缺血性脑卒中炎性反应的机制。方法: SD大鼠随机分为假手术组、模型组、维生素D3组和电头针组，每组15只。采用线栓法建立大脑中动脉栓塞大鼠模型。电头针组给予双侧“顶颞前斜线”电针干预，留针30 min，1次/d，共7 d。维生素D3组给予1，25-VitD3溶液（3 ng·100 g-1·d-1）灌胃，1次/d，共7 d。对各组大鼠进行神经功能缺损评分和神经行为学评分。TTC染色法检测大鼠脑梗死体积，免疫荧光法检测大鼠缺血大脑皮层区CYP24a、CYP27a1和CYP27b1的阳性表达，实时荧光定量PCR法检测大鼠缺血大脑皮层区STAT4和STAT6 mRNA的表达，Western blot法检测大鼠缺血大脑皮层区TNF-α、IL-1β、IL-4的表达。结果: 与假手术组比较，模型组大鼠神经功能缺损评分和神经行为学评分升高（P<0.01），脑梗死体积增大（P<0.01），缺血大脑皮层区CYP27a1和CYP27b1阳性表达、STAT6 mRNA和IL-4蛋白水平表达下调（P<0.01），CYP24a阳性表达、STAT4 mRNA和TNF-α、IL-1β蛋白水平表达上调（P<0.01）。与模型组比较，维生素D3组和电头针组神经功能缺损评分和神经行为学评分降低（P<0.01），脑梗死体积明显缩小（P<0.01），CYP27a1和CYP27b1阳性表达、STAT6 mRNA和IL-4蛋白水平表达上调（P<0.01），CYP24a阳性表达、STAT4 mRNA和TNF-α、IL-1β蛋白水平表达下调（P<0.01）。结论: 调控CYP27a1、CYP27b1与CYP24a之间的平衡，使维生素D向活性维生素D3转化，抑制维生素D3降解，调节Th1/Th2平衡，可能是电头针缓解缺血性脑卒中炎性反应的机制之一。.
Keywords: CYP24a; CYP27a1/b1; Electro-scalp acupuncture; Inflammation; Ischemic stroke.