Study on the effect and mechanism of isorhyncophylline on cognitive impairment in rats with acute cerebral infarction
Objective To investigate the effect of isorhyncophylline on cognitive impairment in rats with acute cerebral infarction and its corresponding mechanism.Methods SD rats were separated into acute cerebral infarction group,sham operation group,low-dose isorhyncophylline group,high-dose isorhyncophylline group,nimodipine group,and high-dose isorhyncophylline+ADU-S100 group,with 24 rates for each group.Except the sham operation group,the rats in other groups were treated with filament model to construct the model of acute cerebral infarction.In the sham operation group,only the right external carotid artery,common carotid artery and internal carotid artery were exposed,and the filament was not inserted.After successful modeling,the medication was administered once a day for 2 weeks.After the modeling was successful,the rats in the low dose group and the high dose group were given 5 mg/kg and 20 mg/kg respectively,and the same amount of isotonic saline was injected intraperitoneally.Nimodipine group rats were given 30 mg/kg nimodipine by intragastric administration,and the same amount of isotonic saline was also injected intraperitoneally.The rats in high dose isorhyncophylline+ADU-S 100 group were given 20 mg/kg isorhyncophylline by intragastric administration and 20 mg/kg ADU-S 100 intraperitoneally.Rats in sham operation group and acute cerebral infarction group were injected with 10 ml/kg isotonic saline by intragastric administration and intraperitoneal injection.The medication was administered once a day for 2 weeks.The Zela-Longa neurological function score was evaluated in all the rats 24 h after the final medication,and then Morris water maze test was conducted and their escape latency and the number of stays in the original platform quadrant were recorded.The levels of interleukin 6(IL-6)and tumor necrosis factor(TNF)α in serum were detected by enzyme-linked immunosorbent assay(ELISA).The water content of brain tissue was detected in each group.The volume of cerebral infarction was measured by 2,3,5-triphenyltetrazolium chloride(TTC)staining.Evans blue was applied to detect blood-brain barrier permeability.Real-time quantitative polymerase chain reaction(qRT-PCR)was used to detect the expression of ZO-1 and occludin messenger RNA(mRNA)in brain tissue of each group.The expression of STING,phosphorylated tank-bound kinase 1(p-TBK1)and phosphorylated interferon regulatory factor 3(p-IRF3)in rat brain tissues was detected by western blot and compared between groups.Results Compared with sham operation group,the neurological function score([2.96±0.32]vs.0),brain tissue water content([86.9±3.2]％vs.[71.8±3.1]％),serum TNF-a([86.7±3.5]ng/L vs.[35.6±1.7]ng/L)and IL-6([167.8±6.1]ng/L vs.[50.2±2.2]ng/L)levels,cerebral infarction volume([28.6±1.3]mm3 vs.0 mm3),evans blue content([1.57±0.13]g/Lvs.[0.96±0.08]g/L),STING([1.83±0.16]vs.[0.86±0.08]),p-TBK1([0.89±0.07]vs.[0.41±0.03]),and p-IRF3([0.67±0.05]vs.[0.13±0.01])protein expression in brain tissue were increased,expression of ZO-1([0.45±0.04]vs.[1.00±0.00])and occludin mRNA([0.23±0.02]vs.[1.00±0.00])in brain tissue were decreased,the escape latency was prolonged([33.6±1.6]s vs.[12.3±0.5]s),and the number of stays in the original platform quadrant([5.9±0.2]times vs.[15.7±0.4]times)was decreased in the acute cerebral infarction group 24 h after last medication administration(all P＜0.05).(2)Compared with acute cerebral infarction group,the neurological function score([2.37±0.21],[1.14±0.17],[1.18±0.13]vs.[2.96±0.32]),brain tissue water content([81.8±3.0]％,[74.9±3.0]％,[74.3±2.9]％vs.[86.9±3.2]％),serum TNF-α([71.1±1.4]ng/L,[43.4±2.0]ng/L,[41.5±1.9]ng/L vs.[86.7±3.5]ng/L)and IL-6([129.8±5.4]ng/L,[81.2±3.8]ng/L,[80.0±3.6]ng/L vs.[167.8±6.1]ng/L)levels,cerebral infarction volume([21.7±1.0]mm3,[10.5±0.5]mm3,[10.7±0.5]mm3 vs.[28.6±1.3]mm3),evans blue content([1.39±0.12]g/L,[1.16±0.10]g/L,[1.18±0.19]g/L vs.[1.57±0.13]g/L),STING([1.50±0.14],[1.02±0.11],[1.01±0.09]vs.[1.83±0.16]),p-TBK1([0.75±0.05],[0.54±0.04],[0.52±0.05]vs.[0.89±0.07]),and p-IRF3([0.51±0.05],[0.25±0.02],[0.27±0.02]vs.[0.67±0.05])protein expression in brain tissue were decreased,expression of ZO-1([0.58±0.05],[0.87±0.07],[0.89±0.09]vs.[0.45±0.04])and occludin mRNA([0.36±0.03],[0.71±0.06],[0.69±0.05]vs.[0.23±0.02])in brain tissue were increased,the escape latency were shortened([28.6±1.0]s,[16.5±0.7]s,[16.4±0.7]s vs.[33.6±1.6]s),and the number of stays in the original platform quadrant([8.2±0.3]times,[12.8±0.5]times,[12.9±0.5]times vs.[5.9±0.2]times)were increased in the low-dose isorhyncophylline group,high-dose isorhyncophylline group,and nimodipine group(all P＜0.05).(3)Compared with high-dose isorhyncophylline group,the neurological function score([2.12±0.14]vs.[1.14±0.17]),brain tissue water content([78.7±3.2]％vs.[74.9±3.0]％),serum TNF-a([59.7±2.1]ng/L vs.[43.4±2.0]ng/L)and IL-6([118.9±4.6]ng/L vs.[81.2±3.8]ng/L)levels,cerebral infarction volume([16.6±0.4]mm3 vs.[10.5±0.5]mm3),evans blue content([1.36±0.10]g/L vs.[1.16±0.10]g/L),and STING([1.37±0.12]vs.[1.02±0.11]),p-TBK1([0.67±0.05]vs.[0.54±0.04]),and p-IRF3([0.39±0.03]vs.[0.25±0.02])protein expression in brain tissue were increased,expression of ZO-1([0.63±0.05]vs.[0.87±0.07])and occludin mRNA([0.46±0.05]vs.[0.71±0.06])in brain tissue were decreased,the escape latency was prolonged([23.4±1.0]svs.[16.5±0.7]s),and the number of stays in the original platform quadrant([9.6±0.3]times vs.[12.8±0.5]times)was decreased in the isorhyncophylline high-dose+ADU-S100 group(all P＜0.05).Conclusion Isorhyncophylline can inhibit inflammation,reduce blood-brain barrier damage,reduce cerebral edema,and improve cognitive impairment in rats with acute cerebral infarction,and the mechanism of which may be related to the inhibition of STING/TBK1/IRF3 pathway.
万方数据
维普
