Selective brain hypothermia is considered an effective treatment for neuronal injury after stroke,and avoids the complications of general hypothermia.However,the mechanisms by which selective brain hypothermia affects...Selective brain hypothermia is considered an effective treatment for neuronal injury after stroke,and avoids the complications of general hypothermia.However,the mechanisms by which selective brain hypothermia affects mitochondrial fission remain unknown.In this study,we investigated the effect of selective brain hypothermia on the expression of fission 1 (Fis1) protein,a key factor in the mitochondrial fission system,during focal cerebral ischemia/reperfusion injury.Sprague-Dawley rats were divided into four groups.In the sham group,the carotid arteries were exposed only.In the other three groups,middle cerebral artery occlusion was performed using the intraluminal filament technique.After 2 hours of occlusion,the filament was slowly removed to allow blood reperfusion in the ischemia/reperfusion group.Saline,at 4℃ and 37℃,were perfused through the carotid artery in the hypothermia and normothermia groups,respectively,followed by restoration of blood flow.Neurological function was assessed with the Zea Longa 5-point scoring method.Cerebral infarct volume was assessed by 2,3,5-triphenyltetrazolium chloride staining,and apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining.Fis1 and cytosolic cytochrome c levels were assessed by western blot assay.Fis1 mRNA expression was assessed by quantitative reverse transcription-polymerase chain reaction.Mitochondrial ultrastructure was evaluated by transmission electron microscopy.Compared with the sham group,apoptosis,Fis1 protein and mRNA expression and cytosolic cytochrome c levels in the cortical ischemic penumbra and cerebral infarct volume were increased after reperfusion in the other three groups.These changes caused by cerebral ischemia/reperfusion were inhibited in the hypothermia group compared with the normothermia group.These findings show that selective brain hypothermia inhibits Fis1 expression and reduces apoptosis,thereby ameliorating focal cerebral ischemia/reperfusion injury in rats.Experiments were authorized by the Ethics Committee of Qingdao Municipal Hospital of China (approval No.2019008).展开更多
Electroacupuncture preconditioning at acupoint Baihui （GV20） can reduce focal cerebral ischemia/reperfusion injury. However, the precise protective mechanism remains unknown. Mitochondrial fission mediated by dynami...Electroacupuncture preconditioning at acupoint Baihui （GV20） can reduce focal cerebral ischemia/reperfusion injury. However, the precise protective mechanism remains unknown. Mitochondrial fission mediated by dynamin-related protein 1 （Drp1） can trigger neuronal apoptosis following cerebral ischemia/reperfusion injury. Herein, we examined the hypothesis that electroacupuncture pretreatment can regulate Drp1, and thus inhibit mitochondrial fission to provide cerebral protection. Rat models of focal cerebral ischemia/reperfusion injury were established by middle cerebral artery occlusion at 24 hours after 5 consecutive days of preconditioning with electroacupuncture at GV20 （depth 2 mm, intensity 1 mA, frequency 2/15 Hz, for 30 minutes, once a day）. Neurological function was assessed using the Longa neurological deficit score. Pathological changes in the ischemic penumbra on the injury side were assessed by hematoxylin-eosin staining. Cellular apoptosis in the ischemic penumbra on the injury side was assessed by terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling staining. Mitochondrial ultrastructure in the ischemic penumbra on the injury side was assessed by transmission electron microscopy. Drp1 and cytochrome c expression in the ischemic penumbra on the injury side were assessed by western blot assay. Results showed that electroacupuncture preconditioning decreased expression of total and mitochondrial Drp1, decreased expression of total and cytosolic cytochrome c, maintained mitochondrial morphology and reduced the proportion of apoptotic cells in the ischemic penumbra on the injury side, with associated improvements in neurological function. These data suggest that electroacupuncture preconditioning-induced neuronal protection involves inhibition of the expression and translocation of Drp1.展开更多
Objective：To observe the protective effects of safflor Injection（SI） and extract of Ginkgo biloba（EGB） on lung ischemia-reperfusion injury（LIRI） and investigate its mechanism.Methods：In vivo rabbit model of LI...Objective：To observe the protective effects of safflor Injection（SI） and extract of Ginkgo biloba（EGB） on lung ischemia-reperfusion injury（LIRI） and investigate its mechanism.Methods：In vivo rabbit model of LIRI was reconstructed.Forty rabbits were randomly and equally divided into four groups：sham-operation group（sham group）,ischemia-reperfusion group（model group）,ischemia-reperfusion plus SI group（safflor group） and ischemia-reperfusion plus EGB injection group（EGB group）.Malondialdehyde（MDA） content,superoxide dismutase（SOD） and xanthine oxidase（XO） activity in serum were measured.The wet/dry weight ratio（W/D） of the lung tissue and activity of myeloperoxidase（MPO） were also tested.Ultrastructure change of the lung tissue was observed by the electron microscope.The expression of intercellular adhesion molecule-1（ICAM-1） was measured by immunohistochemistry（IHC）.Results：In the model group,MDA and XO increased and SOD decreased in serum compared with the sham group（P〈0.01）.The values of W/D,MPO and ICAM-1 of the model group were higher than those of the sham group（P〈0.01）,but those of the safflor group and EGB group were significantly lower than those of the model group（P〈0.01）.The IHC demonstrated that ICAM-1 expression in lung tissue of the model group was significantly higher than those of the safflor group（P〈0.01）.Compared with safflor group,in the EGB group MDA,XO,MPO decreased,SOD and ICAM-1expression increased（P〈0.05）,but the change of W/D was not statistically significant（P〉0.05）.Conclusions：SI and EGB may attenuate LIRI through antioxidation,inhibition of neutrophil aggregation and down-regulation of ICAM-1expression.But EGB had more effect on the antioxidation,while SI did better on regulating ICAM-1 expression.展开更多
Background Many studies have indicated that hyperpolarizing cardioplegia is responsible for myocardial preservation and researchers have suggested that the adenosine triphosphate-sensitive potassium channels （KATe） ...Background Many studies have indicated that hyperpolarizing cardioplegia is responsible for myocardial preservation and researchers have suggested that the adenosine triphosphate-sensitive potassium channels （KATe） were the end effectors of cardio-protection. But whether mitochondrial KATe plays an important role in hyperpolarizing cardioplegia is not apparent. The present study investigated the effect of hyperpolarizing cardioplegia containing pinacidil （a nonselective KATe opener） on ischemia/repeffusion injury in rat hearts, especially the role of mitochondrial KATe in pinacidil hyperpolarizing cardioplegia. Methods Sprague-Dawley rat hearts were Langendorff-perfused for 20 minutes with Krebs-Henseleit buffer at 37℃ before equilibration. Cardiac arrest was then induced in different treatments： there was no arrest and ischemia in the normal group, the control group were arrested by clamping the aorta, depolarizing caidioplegia （St. Thomas solution containing 16 mmol/L KCI） and hyperpolarizing cardioplegia groups used St. Thomas solution containing 0.05 mmol/L pinacidil and 5 mmol/L KCI to induce cardiac arrest in group hyperkalemic and group pinacidil, in group hyperkalemic ＋ 5-hydroxydecanote （5HD） and Pinacidil ＋ 5HD, 5HD （0.1 retool/L） was added to the above two solutions to block mitochondria KATe channels. Global ischemia was then administrated for 40 minutes at 37℃, followed by 30 minutes of reperfusion. At the end of equilibration and reperfusion, hemodynamics, ultrastructure, and mitochondrial function were measured. Results In the control group, ischemia/reperfusion decreased the left ventricular developed pressure, heart rate, coronary flow, mitochondrial membrane potential, impaired mitochondrial respiratory function, increased reactive oxygen species and left ventricular end diastolic pressure. Damage to myocardial ultrastructure was also evident. Both depolarized arrest and especially hyperpolarized cardioplegia significantly reduced these lesions. 5HD partially blocked the beneficial effects of pinacidil cardioplegia but showing no effects on hyperkalemic arrest. Conclusions Pinacidil cardioplegia provides better cardioprotection with preservation of hemodynamics, ultrastructure, and mitochondrial function than traditional cardioplegia. The mitochondria KATe channels may play an important role in the protection mechanism.展开更多
目的:探讨重组人促红细胞生成素(recombinant human erythropoietin,rhEPO)对急性高眼压视网膜缺血所致的视神经和视网膜超微结构损害的保护作用。方法:将12只健康新西兰白兔平均分为模型组和EPO组。两组兔均任选1眼作为实验眼,用生理...目的:探讨重组人促红细胞生成素(recombinant human erythropoietin,rhEPO)对急性高眼压视网膜缺血所致的视神经和视网膜超微结构损害的保护作用。方法:将12只健康新西兰白兔平均分为模型组和EPO组。两组兔均任选1眼作为实验眼,用生理盐水前房灌注法造成急性高眼压模型。造模前第3d及造模结束时,EPO组兔皮下注射rhEPO100U/kg共两次。第7d进行视神经和视网膜的超微结构观察。结果:急性高眼压使视神经和视网膜的超微结构受到明显损害,全身使用rhEPO后这种损害显著减轻。结论:rhEPO能够减轻急性高眼压引起的视神经和视网膜超微结构损害。rhEPO可能成为新的视神经保护药物。展开更多
基金supported by the Natural Science Foundation of Shandong Province of China,No.ZR2015HM023(to MSW)the Science and Technology Plan Project of Qingdao City of China,No.19-6-1-50-nsh(to MSW)
文摘Selective brain hypothermia is considered an effective treatment for neuronal injury after stroke,and avoids the complications of general hypothermia.However,the mechanisms by which selective brain hypothermia affects mitochondrial fission remain unknown.In this study,we investigated the effect of selective brain hypothermia on the expression of fission 1 (Fis1) protein,a key factor in the mitochondrial fission system,during focal cerebral ischemia/reperfusion injury.Sprague-Dawley rats were divided into four groups.In the sham group,the carotid arteries were exposed only.In the other three groups,middle cerebral artery occlusion was performed using the intraluminal filament technique.After 2 hours of occlusion,the filament was slowly removed to allow blood reperfusion in the ischemia/reperfusion group.Saline,at 4℃ and 37℃,were perfused through the carotid artery in the hypothermia and normothermia groups,respectively,followed by restoration of blood flow.Neurological function was assessed with the Zea Longa 5-point scoring method.Cerebral infarct volume was assessed by 2,3,5-triphenyltetrazolium chloride staining,and apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining.Fis1 and cytosolic cytochrome c levels were assessed by western blot assay.Fis1 mRNA expression was assessed by quantitative reverse transcription-polymerase chain reaction.Mitochondrial ultrastructure was evaluated by transmission electron microscopy.Compared with the sham group,apoptosis,Fis1 protein and mRNA expression and cytosolic cytochrome c levels in the cortical ischemic penumbra and cerebral infarct volume were increased after reperfusion in the other three groups.These changes caused by cerebral ischemia/reperfusion were inhibited in the hypothermia group compared with the normothermia group.These findings show that selective brain hypothermia inhibits Fis1 expression and reduces apoptosis,thereby ameliorating focal cerebral ischemia/reperfusion injury in rats.Experiments were authorized by the Ethics Committee of Qingdao Municipal Hospital of China (approval No.2019008).
基金supported by the Natural Science Foundation of Shandong Province of China,No.ZR2015HM023a grant from the Science and Technology Plan Project of Shinan District of Qingdao City of China,No.2016-3-029-YY
文摘Electroacupuncture preconditioning at acupoint Baihui （GV20） can reduce focal cerebral ischemia/reperfusion injury. However, the precise protective mechanism remains unknown. Mitochondrial fission mediated by dynamin-related protein 1 （Drp1） can trigger neuronal apoptosis following cerebral ischemia/reperfusion injury. Herein, we examined the hypothesis that electroacupuncture pretreatment can regulate Drp1, and thus inhibit mitochondrial fission to provide cerebral protection. Rat models of focal cerebral ischemia/reperfusion injury were established by middle cerebral artery occlusion at 24 hours after 5 consecutive days of preconditioning with electroacupuncture at GV20 （depth 2 mm, intensity 1 mA, frequency 2/15 Hz, for 30 minutes, once a day）. Neurological function was assessed using the Longa neurological deficit score. Pathological changes in the ischemic penumbra on the injury side were assessed by hematoxylin-eosin staining. Cellular apoptosis in the ischemic penumbra on the injury side was assessed by terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling staining. Mitochondrial ultrastructure in the ischemic penumbra on the injury side was assessed by transmission electron microscopy. Drp1 and cytochrome c expression in the ischemic penumbra on the injury side were assessed by western blot assay. Results showed that electroacupuncture preconditioning decreased expression of total and mitochondrial Drp1, decreased expression of total and cytosolic cytochrome c, maintained mitochondrial morphology and reduced the proportion of apoptotic cells in the ischemic penumbra on the injury side, with associated improvements in neurological function. These data suggest that electroacupuncture preconditioning-induced neuronal protection involves inhibition of the expression and translocation of Drp1.
文摘Objective：To observe the protective effects of safflor Injection（SI） and extract of Ginkgo biloba（EGB） on lung ischemia-reperfusion injury（LIRI） and investigate its mechanism.Methods：In vivo rabbit model of LIRI was reconstructed.Forty rabbits were randomly and equally divided into four groups：sham-operation group（sham group）,ischemia-reperfusion group（model group）,ischemia-reperfusion plus SI group（safflor group） and ischemia-reperfusion plus EGB injection group（EGB group）.Malondialdehyde（MDA） content,superoxide dismutase（SOD） and xanthine oxidase（XO） activity in serum were measured.The wet/dry weight ratio（W/D） of the lung tissue and activity of myeloperoxidase（MPO） were also tested.Ultrastructure change of the lung tissue was observed by the electron microscope.The expression of intercellular adhesion molecule-1（ICAM-1） was measured by immunohistochemistry（IHC）.Results：In the model group,MDA and XO increased and SOD decreased in serum compared with the sham group（P〈0.01）.The values of W/D,MPO and ICAM-1 of the model group were higher than those of the sham group（P〈0.01）,but those of the safflor group and EGB group were significantly lower than those of the model group（P〈0.01）.The IHC demonstrated that ICAM-1 expression in lung tissue of the model group was significantly higher than those of the safflor group（P〈0.01）.Compared with safflor group,in the EGB group MDA,XO,MPO decreased,SOD and ICAM-1expression increased（P〈0.05）,but the change of W/D was not statistically significant（P〉0.05）.Conclusions：SI and EGB may attenuate LIRI through antioxidation,inhibition of neutrophil aggregation and down-regulation of ICAM-1expression.But EGB had more effect on the antioxidation,while SI did better on regulating ICAM-1 expression.
基金This project was supported by a grant from the National Natural Science Foundation of China （No. 30460132）.
文摘Background Many studies have indicated that hyperpolarizing cardioplegia is responsible for myocardial preservation and researchers have suggested that the adenosine triphosphate-sensitive potassium channels （KATe） were the end effectors of cardio-protection. But whether mitochondrial KATe plays an important role in hyperpolarizing cardioplegia is not apparent. The present study investigated the effect of hyperpolarizing cardioplegia containing pinacidil （a nonselective KATe opener） on ischemia/repeffusion injury in rat hearts, especially the role of mitochondrial KATe in pinacidil hyperpolarizing cardioplegia. Methods Sprague-Dawley rat hearts were Langendorff-perfused for 20 minutes with Krebs-Henseleit buffer at 37℃ before equilibration. Cardiac arrest was then induced in different treatments： there was no arrest and ischemia in the normal group, the control group were arrested by clamping the aorta, depolarizing caidioplegia （St. Thomas solution containing 16 mmol/L KCI） and hyperpolarizing cardioplegia groups used St. Thomas solution containing 0.05 mmol/L pinacidil and 5 mmol/L KCI to induce cardiac arrest in group hyperkalemic and group pinacidil, in group hyperkalemic ＋ 5-hydroxydecanote （5HD） and Pinacidil ＋ 5HD, 5HD （0.1 retool/L） was added to the above two solutions to block mitochondria KATe channels. Global ischemia was then administrated for 40 minutes at 37℃, followed by 30 minutes of reperfusion. At the end of equilibration and reperfusion, hemodynamics, ultrastructure, and mitochondrial function were measured. Results In the control group, ischemia/reperfusion decreased the left ventricular developed pressure, heart rate, coronary flow, mitochondrial membrane potential, impaired mitochondrial respiratory function, increased reactive oxygen species and left ventricular end diastolic pressure. Damage to myocardial ultrastructure was also evident. Both depolarized arrest and especially hyperpolarized cardioplegia significantly reduced these lesions. 5HD partially blocked the beneficial effects of pinacidil cardioplegia but showing no effects on hyperkalemic arrest. Conclusions Pinacidil cardioplegia provides better cardioprotection with preservation of hemodynamics, ultrastructure, and mitochondrial function than traditional cardioplegia. The mitochondria KATe channels may play an important role in the protection mechanism.
文摘目的:探讨重组人促红细胞生成素(recombinant human erythropoietin,rhEPO)对急性高眼压视网膜缺血所致的视神经和视网膜超微结构损害的保护作用。方法:将12只健康新西兰白兔平均分为模型组和EPO组。两组兔均任选1眼作为实验眼,用生理盐水前房灌注法造成急性高眼压模型。造模前第3d及造模结束时,EPO组兔皮下注射rhEPO100U/kg共两次。第7d进行视神经和视网膜的超微结构观察。结果:急性高眼压使视神经和视网膜的超微结构受到明显损害,全身使用rhEPO后这种损害显著减轻。结论:rhEPO能够减轻急性高眼压引起的视神经和视网膜超微结构损害。rhEPO可能成为新的视神经保护药物。
