Effects of N-butylphthalide on the expressions of ZO-1 and claudin-5 in blood-brain barrier of rats with acute carbon monoxide poisoning
10.3760/cma.j.issn.2095-4352.2018.05.006
- VernacularTitle:丁苯酞对急性一氧化碳中毒大鼠血脑屏障ZO-1和claudin-5蛋白表达的影响
- Author:
Li WANG
1
,
2
;
Xiaoyu DING
;
Mingjun BI
;
Jinglin WANG
;
Yong ZOU
;
Jiyou TANG
;
Qin LI
Author Information
1. 264000 山东烟台,青岛大学附属烟台毓璜顶医院中西医结合科
2. 250014 山东济南,山东大学附属千佛山医院神经内科
- Keywords:
Carbon monoxide poisoning;
N-butylphthalide;
Blood-brain barrier;
claudin-5;
ZO-1
- From:
Chinese Critical Care Medicine
2018;30(5):422-427
- CountryChina
- Language:Chinese
-
Abstract:
Objective To explore the effects of N-butylphthalide on the expressions of ZO-1 and claudin-5 in blood-brain barrier (BBB) in rats with acute carbon monoxide (CO) poisoning. Methods A total of 144 adult healthy male Sprague-Dawley (SD) rats were randomly divided into normal control group, CO poisoning group, and NBP treatment group, with 48 rats in each group. The acute CO poisoning model was reproduced in hyperbaric oxygen chamber, and all model rats were given hyperbaric oxygen therapy once daily. The rats in the normal control group were free to breathe fresh air. The rats in NBP treatment group were administered orally NBP 60 mg/kg twice a day at 2 hours after poisoning until death. The rats in normal control group and CO poisoning group were treated with equal amount of pure olive oil. Four rats were sacrificed from each group at 1, 3, 7, 14 days after model reproducing, respectively. The changes in ultrastructure of BBB were observed under transmission electron microscope. The expressions of ZO-1 and claudin-5 proteins were determined by immunofluorescence staining and Western Blot. The localization of the two target proteins was observed by immunofluorescence double staining. The correlation between the two proteins was analyzed by linear regression. Results The ultrastructure of BBB was normal in normal control group, some ZO-1 and a large number of claudin-5 positive cells were observed. The ultrastructure of BBB was seriously injured, ZO-1 and claudin-5 positive cells in brain tissue were significantly decreased, and the expressions of ZO-1 and claudin-5 proteins in brain tissue at 1 day after poisoning in CO poisoning group were significantly lower than those of normal control group (ZO-1 protein:3.38±0.30 vs. 24.50±5.62, claudin-5 protein: 11.38±0.93 vs. 46.35±6.88, both P < 0.05), and although gradually restored, they were maintained at relatively lower levels until 14 days as compared with those in normal control group (ZO-1 protein: 10.35±0.80 vs. 24.63±3.57, claudin-5 protein: 32.35±3.11 vs. 46.43±7.20, both P < 0.05). NBP treatment could significantly alleviate the ultrastructure injury of BBB induced by acute CO poisoning, the amount of ZO-1 and claudin-5 positive cells in brain tissue were significantly increased, as well as the expressions of ZO-1 and claudin-5 proteins were significantly increased, which were significantly higher than those of CO poisoning group from 1 day and 3 days on, respectively (1-day ZO-1 protein: 7.57±0.69 vs. 3.38±0.30, 3-day claudin-5 protein:20.46±1.42 vs. 11.43±0.86, both P < 0.05), and which showed an increase tendency with time prolongation. The results of immunofluorescence double staining showed that ZO-1 and claudin-5 proteins could not only coexist in the same cell, but also could be expressed separately in different cells. Linear regression analysis showed the positive correlation between the expressions of ZO-1 and claudin-5 proteins in brain tissue of rats with acute CO poisoning (R2= 0.917, P = 0.022). Conclusion NBP could markedly improve the ultrastructure and functional integrity of BBB through up-regulating the expressions of ZO-1 and claudin-5 proteins, and then reduce brain damage caused by CO poisoning.
