Effects of tert-butyl hydroperoxide on the expression of second mitochondria- derived activator of caspase and X-linked inhibitor of apoptosis in mitochondrial pathway after cerebral ischemia/reperfusion injury in rats
10.3760/cma.j.issn.1008-6706.2021.03.019
- VernacularTitle:叔丁基对苯二酚对脑缺血再灌注后大鼠线粒体通路第2个天冬氨酸特异性半胱氨酸蛋白酶激活物和凋亡抑制蛋白表达的影响
- Author:
Chao ZENG
;
Jing CHEN
;
Wenbing LIU
;
Kang LIANG
;
Hui LI
;
Jing WANG
;
Ruijie MA
- From:
Chinese Journal of Primary Medicine and Pharmacy
2021;28(3):405-410
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the effects of tert-butyl hydroperoxide (TBH) on the expression of second mitochondria-derived activator of caspase (Smac) and X-linked inhibitor of apoptosis (XIAP) in mitochondrial pathway after cerebral ischemia/reperfusion injury in rats.Methods:From March to December in 2019, 45 healthy male Sprague-Dawley rats were randomly divided into sham-operation, model and TBH groups. Rat models of cerebral ischemia/reperfusion injury were established by ligation of the left carotid artery. Rat neurological function was evaluated to exclude the rats that failed in cerebral ischemia/reperfusion injury induction. Ten rats were left in each group. At 0.5 and 12 hours after cerebral ischemia/reperfusion injury, rats in the TBH group were treated by intragastric administration of 12.5 mg/kg TBH and those in the sham-operation and model groups were identically treated by intragastric administration of equal volume of 0.9% sodium chloride injection. After 24 hours of reperfusion, rat neurological function was assessed in each group. Then the rats were killed and the brains were harvested. Apoptosis of nerve cells was detected by terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL) assay. The levels of superoxide dismutase (SOD), malondialdehyde (MDA), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in the brain tissue were detected by enzyme-linked immunosorbent assay. XIAP- and Smac-positive cell count and protein expression were determined by immunohistochemical staining and western blot assay, respectively.Results:Rat neurological function score in the TBH group was significantly lower than that in the model group [(1.36 ± 0.49) points vs. (3.73 ± 0.97) points, t = 6.896, P < 0.001]. In the TBH group, a large number of apoptotic nerve cells were found in the ischemic cerebral cortex, but the number of apoptotic nerve cells in the TBH group was significantly smaller than that in the model group. In the model group, SOD level was significantly lower, MDA, TNF-α and IL-1β levels were significantly higher compared with the sham-operation group [SOD: (51.94 ± 3.46) U/mg vs. (70.68 ± 2.67) U/mg, t = 13.560, P < 0.001; MDA: (5.69 ± 0.78) nmol/mg vs. (1.20 ± 0.96) nmol/mg, t = 11.479, P < 0.001; TNF-α: (89.36 ± 9.84) pg/mg vs. (40.53 ± 4.35) pg/mg, t = 14.353, P < 0.001; IL-1β: (41.35 ± 6.79) pg/mg vs. (17.22 ± 2.31) pg/mg, t = 10.639, P < 0.001]. In the TBH group, SOD level was significantly higher, MDA, TNF-α and IL-1β levels were significantly lower compared with the model group [SOD: (51.94 ± 3.46) U/mg vs. (68.84 ± 5.03) U/mg, t = 8.754, P < 0.001; MDA: (5.69 ± 0.78) nmol/mg vs. (2.46 ± 0.48) nmol/mg, t = 11.153, P < 0.001; TNF-α: (89.36 ± 9.84) pg/mg vs. (57.64 ± 6.22) pg/mg, t = 8.617, P < 0.001; IL-1β: (41.35 ± 6.79) pg/mg vs. (23.84 ± 5.48) pg/mg, t = 6.346, P < 0.001]. XIAP- and Smac-positive cell count and protein expression in the model group were significantly greater than those in the sham-operation group [XIAP-positive cell count: (22.63 ± 4.37) vs. (12.39 ± 3.18), t = 5.992, P < 0.001, Smac-positive cell count: (47.58 ± 6.94) vs. (5.64 ± 1.35), t = 18.759, P < 0.001; XIAP protein expression: (0.53 ± 0.08) vs. (0.24 ± 0.05), t = 9.721, P < 0.001; Smac protein expression: (0.92 ± 0.15) > ( 0.36 ± 0.05), t = 11.200, P < 0.001 ]. In the TBH group, XIAP-positive cell count and XIAP protein expression were significantly higher and Smac-positive cell count and Smac protein expression were significantly lower compared with the model group [XIAP-positive cell count: (36.78 ± 5.26) vs. (22.63 ± 4.37), t = 6.543, P < 0.001, Smac-positive cell count: (31.74 ± 4.26) vs. (47.58 ± 6.94), t = 6.151, P < 0.001; XIAP protein expression: (0.79 ± 0.10) vs. (0.53 ± 0.08), t = 6.420, P < 0.001, Smac protein expression: (0.70 ± 0.09) vs. (0.92 ± 0.15), t = 3.977, P < 0.001]. Conclusion:TBH can effectively reduce neuronal apoptosis, oxidative stress and inflammatory reaction after cerebral ischemia/reperfusion injury, which may be related to the regulation of XIAP and Smac signaling pathways.
