BACKGROUND: Immediate early gene (lEG) c-jun is a sensitive marker for functional status of nerve cells. Caspase-3 is a cysteine protease, which is a critical regulator of apoptosis. The effect of exogenous nerve g...BACKGROUND: Immediate early gene (lEG) c-jun is a sensitive marker for functional status of nerve cells. Caspase-3 is a cysteine protease, which is a critical regulator of apoptosis. The effect of exogenous nerve growth factor (NGF) on the expression of c-jun mRNA and Caspase-3 protein in striate cortex of rats with transient global cerebral ischemia/reperfusion (IR) is unclear. OBJECTIVE: To study the protective effect of exogenous NGF on the brain of rats with transient globa cerebral IR and its effecting pathway by observing the expression of c-jun mRNA and Caspase-3 protein. DESIGN: Randomized controlled animal trial SETTING: Department of Neural Anatomy, Institute of Brain, China Medical University MATERIALS:Eighteen healthy male SD rats of clean grade, aged 1 to 3 months, with body mass of 250 to 300 g, were involved in this study. NGF was provided by Dalian Svate Pharmaceutical Co.,Ltd. c-jun in situ hybridization detection kit, Caspase-3 antibody and SABC kit were purchased from Boster Biotechnology Co.. Ltd. METHODS: This trial was carried out in the Department of Neural Anatomy, Institute of Brain, China Medical University during September 2003 to April 2005. (1) Experimental animals were randomized into three groups with 6 in each: sham-operation group, IR group and NGF group.(2)After the rats were anesthetized, the bilateral common carotid arteries and right external carotid arteries of rats were bluntly dissected and bilateral common carotid arteries were clamped for 30 minutes with bulldog clamps. Reperfusion began after buldog clamps were removed. Normal saline of lmL and NGF (1×10^6 U/L) of 1 mL was injected into the common carotid artery of rats via right external carotid arteries in the IR group and NGF group respectively. The injection was conducted within 30 minutes, and then the right external carotid arteries were ligated. In the sham-operation group, occlusion of bilateral common carotid arteries and administration of drugs were omitted.GAll the rats were executed by decollation at 3 hours after modeling. The animals were fixed with phosphate buffer solution (PBS, 0.1 mol/L) containing 40 g/L polyformaldehyde, their brains were quickly removed. The coronal section tissue mass containing striate cortex about 3 mm before line between two ears was taken and made into successive frozen sections.(4)The expression of c-jun mRNA and Caspase-3 protein in striate cortex of global cerebral ischemia rats were detected with in situ hybridization, immunohistochemistry and microscope image analysis. (5)t test was used for comparing the difference of the measurement data. MAIN OUTCOME MEASURES:Comparison of the expression of lEG c-jun mRNA and Caspase-3 protein in striate cortex of brain of rats in each group. RESULTS:All the 18 SD rats were involved in the analysis of results. The c-jun mRNA and Caspase-3 protein positive reaction cells were found brown yellow in the striate cortex of rats, and most of them were in lamellas Ⅱ and Ⅲ, mainly presenting round or oval. The expression of c-jun mRNA and Caspase-3 protein in sham-operation group was weak or negative. The average gray value of c-jun mRNA and Caspase-3 protein in the IR group was significantly lower than that in the sham-operation group (49.52±4.13 vs. 95.48± 5.28; 74.73±4.29 vs. 162.38±9.16,P 〈 0.01). The average gray value of c-jun mRNA and Caspase-3 protein in the NGF group was significantly higher than that in the IR group (63.96±4.25 vs.49.52±4.13; 83.98± 4.13 vs. 74.73±4.29, P〈 0.05). CONCLUSION: NGF can protect ischemic neurons by down-regulating the expression of c-jun mRNA and Caspase-3 protein in striate cortex of global cerebral ischemia rats.展开更多
Cerebral ischemia/reperfusion injury impairs learning and memory in patients.Studies have shown that synaptic function is involved in the formation and development of memory,and that DNA methylation plays a key role i...Cerebral ischemia/reperfusion injury impairs learning and memory in patients.Studies have shown that synaptic function is involved in the formation and development of memory,and that DNA methylation plays a key role in the regulation of learning and memory.To investigate the role of DNA hypomethylation in cerebral ischemia/reperfusion injury,in this study,we established a rat model of cerebral ischemia/reperfusion injury by occlusion of the middle cerebral artery and then treated the rats with intraperitoneal 5-aza-2′-deoxycytidine,an inhibitor of DNA methylation.Our results showed that 5-aza-2′-deoxycytidine markedly improved the neurological function,and cognitive,social and spatial memory abilities,and dose-dependently increased the synaptic density and the expression of SYP and SHANK2 proteins in the hippocampus in a dose-dependent manner in rats with cerebral ischemia/reperfusion injury.The effects of 5-aza-2′-deoxycytidine were closely related to its reduction of genomic DNA methylation and DNA methylation at specific sites of the Syp and Shank2 genes in rats with cerebral ischemia/reperfusion injury.These findings suggest that inhibition of DNA methylation by 5-aza-2′-deoxycytidine promotes the recovery of learning and memory impairment in a rat model of cerebral ischemia/reperfusion injury.These results provide theoretical evidence for stroke treatment using epigenetic methods.展开更多
Proteasome activity reduction is an important pathological phenomenon, resulting in proteins aggregation and neuronal death in the injured neurons induced by transient ischemia. Our previous report showed that the tra...Proteasome activity reduction is an important pathological phenomenon, resulting in proteins aggregation and neuronal death in the injured neurons induced by transient ischemia. Our previous report showed that the trap of proteasome in the protein aggregates was a reason to lead to the reduction of proteasome activity. However, the patterns of proteasome entered into protein aggregates are not clear. In this study, we used a global ischemia model, Hematoxylin-Eosin staining, differential centrifuge, proteasome activity assay, sucrose gradient density centrifuge, and Western blot analysis to investigate this problem. Our results show that there are two aggregation patterns of proteasome after transient ischemia and reperfusion. One is that 26S proteasome is trapped by protein aggregates as a whole unit, and the other is that 19S or 20S is trapped in the protein aggregates, respectively, after 26S disassociates.展开更多
BACKGROUND: Proteasome dysfunction has been reported to induce abnormal protein aggregation and cell death. OBJECTIVE: To investigate the effect of proteasome changes on delayed neuronal death in CA1 and dentate gyr...BACKGROUND: Proteasome dysfunction has been reported to induce abnormal protein aggregation and cell death. OBJECTIVE: To investigate the effect of proteasome changes on delayed neuronal death in CA1 and dentate gyrus (DG) regions of the rat hippocampus following transient cerebral ischemia. DESIGN, TIME AND SETTING: A randomized, controlled animal experiment. The study was performed at the Department of Biochemistry and Molecular Biology, Norman Bethune Medical College of Jilin University, from September 2006 to May 2008. MATERIALS: Rabbit anti-19S S10B polyclonal antibody was purchased from Bioreagents, USA; propidium iodide and fluorescently-labeled goat anti-rabbit IgG were purchased from Jackson Immunoresearch, USA; hematoxylin and eosin staining solution was purchased from Sigma, USA; LSM 510 confocal microscope was purchased from Zeiss, Germany. METHODS: A total of 40 healthy Wistar rats, male, 4 months old, were randomly divided into sham surgery group (n = 8) and model group (n = 32). Ischemic models were established in the model group by transient clamping of the bilateral carotid arteries and decreased blood pressure. After 20 minutes of global ischemia, the clamp was removed to allow blood flow for 30 minutes, 4, 24 and 72 hours, respectively, with 8 rats at each time point. The bilateral carotid arteries were not ligated in the sham surgery group. MAIN OUTCOME MEASURES: Neuronal death in the CA1 and DG regions was observed by hematoxylin-eosin staining. Proteasome expression in CA1 and DG region neurons was detected by immunohistochemistry. RESULTS: Hematoxylin-eosin staining showed neuronal death in the CA1 region alone at 72 hours of reperfusion following ischemia. In comparison to the sham surgery group, a significant decrease in proteasome expression was observed, by immunohistochemistry, in the CA1 and DG regions in the model group, following 30 minutes, 4, 24, and 72 hours of reperfusion (P 〈 0.01). After 72 hours of reperfusion following ischemia, proteasome expression had almost completely disappeared in the CA1 region. In contrast, neurons of the DG region showed minimized proteasome expression at 24 hours, with a slight increase at 72 hours (P 〈 0.01). CONCLUSION: The alteration of proteasome following ischemia/reperfusion in the neurons of hippocampal CA1 and DG regions reduces the ability of cells to degrade abnormal protein, which may be an important factor resulting in delayed neuronal death following transient cerebral ischemia.展开更多
ATP depletion is one of the pathological bases in cerebral ischemia.Electro-acupuncture(EA)is widely used in clinical practice for ischemia.However,the mechanism of EA remains unclear.The purpose of this study was to ...ATP depletion is one of the pathological bases in cerebral ischemia.Electro-acupuncture(EA)is widely used in clinical practice for ischemia.However,the mechanism of EA remains unclear.The purpose of this study was to investigate whether EA could activate the AMPK/PGC-1α/TFAM signaling pathway and,consequently,increase the preservation of ATP in rats with ischemia.In this study,48 rats were randomly divided into four groups as a sham-operation control group(sham group),a middle cerebral artery occlusion group(MCAO group),an EA group,and an EA group blocked by the AMPK inhibitor compound C(EA+CC group)(N=12/group).The rats of the EA group and EA+CC group received the EA treatment for 7 days.The rats that belonged in the two remaining groups were only grasped in the same condition.Then,their brain tissues were collected for further detection.When compared with other groups,EA significantly reduced neurological deficits score and increased motor function.The cerebral infarction volume was significantly reduced in the EA group according to TTC staining.With western blot,we found that EA improved the ratio of p-AMPKα/AMPKα(P<0.05),however,there is no difference between the MCAO group and sham group(P>0.05).In addition,EA also increased the expression of PGC-1αand TFAM(all P<0.05).By Elisa,we observed that EA increased the preservation of ATP(P<0.05)and mitochondrial respiratory enzymes,including Complex I(P<0.05),Complex IV(P<0.05),but not Complex III(P>0.05).In summary,we conclude that EA may protect against ischemic damage in MCAO rats,improve the preservation of ATP and mitochondrial respiratory enzymes.This effect may be positively regulated by the activation of the PGC-1α/TFAM signaling pathway.展开更多
Recently,we have reported that Oenanthe javanica extract(OJE)displays strong neuroprotective effect against ischemic damage after transient global cerebral ischemia.However,neuroprotective mechanisms of OJE have not b...Recently,we have reported that Oenanthe javanica extract(OJE)displays strong neuroprotective effect against ischemic damage after transient global cerebral ischemia.However,neuroprotective mechanisms of OJE have not been fully identified.Thus,this study investigated the neuroprotection of OJE in the hippocampal CA1 area and its anti-inflammatory activity in gerbils subjected to 5 minutes of transient global cerebral ischemia.We treated the animals by intragastrical injection of OJE(100 and 200 mg/kg)once daily for 1 week prior to transient global cerebral ischemia.Neuroprotection of OJE was observed by immunohistochemistry for neuronal nuclear antigen and histofluorescence staining for Fluoro-Jade B.Immunohistochemistry of glial fibrillary acidic protein and ionized calcium-binding adapter molecule 1 was done for astrocytosis and microgliosis,respectively.To investigate the neuroprotective mechanisms of OJE,we performed immunohistochemistry of tumor necrosis factor-alpha and interleukin-2 for pro-inflammatory function and interleukin-4 and interleukin-13 for anti-inflammatory function.When we treated the animals by intragastrical administration of 200 mg/kg of OJE,hippocampal CA1 pyramidal neurons were protected from transient global cerebral ischemia and cerebral ischemia-induced gliosis was inhibited in the ischemic hippocampal CA1 area.We also found that interleukin-4 and-13 immunoreactivities were significantly increased in pyramidal neurons of the ischemic CA1 area after OJE pretreatment,and the increased immunoreactivities were sustained in the CA1 pyramidal neurons after transient global cerebral ischemia.However,OJE pretreatment did not increase interleukin-2 and tumor necrosis factor-alpha immunoreactivities in the CA1 pyramidal neurons.Our findings suggest that pretreatment with OJE can protect neurons and attenuate gliosis from transient global cerebral ischemia via increasing expressions of interleukin-4 and-13.The experimental plan of this study was reviewed and approved by the Institutional Animal Care and Use Committee(IACUC)in Kangwon National University(approval No.KW-160802-1)on August 10,2016.展开更多
Ilexonin A is a compound isolated from the root of Ilex pubescens,a traditional Chinese medicine.Ilexonin A has been shown to play a neuroprotective role by regulating the activation of astrocytes and microglia in the...Ilexonin A is a compound isolated from the root of Ilex pubescens,a traditional Chinese medicine.Ilexonin A has been shown to play a neuroprotective role by regulating the activation of astrocytes and microglia in the peri-infarct area after ischemia.However,the effects of ilexonin A on astrocytes and microglia in the infarct-free region of the hippocampal CA1 region remain unclear.Focal cerebral ischemia models were established by 2-hour occlusion of the middle cerebral artery in rats.Ilexonin A(20,40 or 80 mg/kg)was administered immediately after ischemia/reperfusion.The astrocyte marker glial fibrillary acidic protein,microglia marker Iba-1,neural stem cell marker nestin and inflammation markers were detected by immunohistochemistry and western blot assay.Expression levels of tumor necrosis factor-αand interleukin 1βwere determined by enzyme linked immunosorbent assay in the hippocampal CA1 tissue.Astrocytes were activated immediately in progressively increasing numbers from 1,3,to 7 days post-ischemia/reperfusion.The number of activated astrocytes further increased in the hippocampal CA1 region after treatment with ilexonin A.Microglial cells remained quiescent after ischemia/reperfusion,but became activated after treatment with ilexonin A.Ilexonin A enhanced nestin expression and reduced the expression of tumor necrosis factor-αand interleukin 1βin the hippocampus post-ischemia/reperfusion.The results of the present study suggest that ilexonin A has a neuroprotective effect in the hippocampus after ischemia/reperfusion,probably through regulating astrocytes and microglia activation,promoting neuronal stem cell proliferation and reducing the levels of pro-inflammatory factors.This study was approved by the Animal Ethics Committee of the Fujian Medical University Union Hospital,China.展开更多
In this study, we tried to verify the neuroprotective effect of Chrysanthemum indicum Linne(CIL) extract, which has been used as a botanical drug in East Asia, against ischemic damage and to explore the underlying m...In this study, we tried to verify the neuroprotective effect of Chrysanthemum indicum Linne(CIL) extract, which has been used as a botanical drug in East Asia, against ischemic damage and to explore the underlying mechanism involving the anti-inflammatory approach. A gerbil was given CIL extract for 7 consecutive days followed by bilateral carotid artery occlusion to make a cerebral ischemia/reperfusion model. Then, we found that CIL extracts protected pyramidal neurons in the hippocampal CA1 region(CA1) from ischemic damage using neuronal nucleus immunohistochemistry and Fluoro-Jade B histofluorescence. Accordingly, interleukin-13 immunoreactivities in the CA1 pyramidal neurons of CIL-pretreated animals were maintained or increased after cerebral ischemia/reperfusion. These findings indicate that the pre-treatment of CIL can attenuate neuronal damage/death in the brain after cerebral ischemia/reperfusion via an anti-inflammatory approach.展开更多
The survival of microglia depends on the colony-stimulating factor-1 receptor(CSF1R)signaling pathway under physiological conditions.Ki20227 is a highly selective CSF1R inhibitor that has been shown to change the morp...The survival of microglia depends on the colony-stimulating factor-1 receptor(CSF1R)signaling pathway under physiological conditions.Ki20227 is a highly selective CSF1R inhibitor that has been shown to change the morphology of microglia.However,the effects of Ki20227 on the progression of ischemic stroke are unclear.In this study,male C57 BL/6 mouse models of focal cerebral ischemic injury were established through the occlusion of the middle cerebral artery and then administered 3 mg/g Ki20227 for 3 successive days.The results revealed that the number of ionized calcium-binding adaptor molecule 1/bromodeoxyuridine double positive cells in the infarct tissue was reduced,the degree of edema was increased,neurological deficits were aggravated,infarct volume was increased,and the number of peri-infarct Nissl bodies was reduced.The number of terminal deoxynucleotidyl transferase dUTP nick-end labeling-positive cells in the peri-infarct tissue was increased.The expression levels of Bax and Cleaved caspase-3 were up-regulated.Bcl-2 expression was downregulated.The expression levels of inflammatory factors and oxidative stress-associated factors were increased.These findings suggested that Ki20227 blocked microglial proliferation and aggravated the pathological progression of ischemia/reperfusion injury in a transient middle cerebral artery occlusion model.This study was approved by the Animal Ethics Committee of Lanzhou University Second Hospital(approval No.D2020-68)on March 6,2020.展开更多
Objective To investigate the therapeutic effect and possible mechanisms of Chinese ptent medicine Naodesheng(NDS) on repeated transient global cerebral ischemia(GCI) in mice. Methods The repeated transient GCI mic...Objective To investigate the therapeutic effect and possible mechanisms of Chinese ptent medicine Naodesheng(NDS) on repeated transient global cerebral ischemia(GCI) in mice. Methods The repeated transient GCI mice were induced by bilateral carotid arteries ligation, and were randomly divided into model group, Sham group without arteries ligation, NDS groups(1.25 and 2.5 g/kg) and positive control(vinpocetine 3.1 mg/kg, VP) group. After oral administration once daily for successive 7 d, the transient GCI was induced. The degree of neurological deficit, histological changes, and neurons loss in the hippocampus were evaluated. In order to investigate the possible mechanisms, the oxidative stress and inflammatory factor were measured after 24 h of GCI. Comparison among multiple groups was performed with one-way analysis of variance(ANOVA). Results NDS could significantly alleviate the neurological function impairment, histological injury, and neurons loss, increase the superoxide dismutase(SOD) activity, decrease the content of malondialdehyde(MDA), and reduce inflammatory factor in the ischemic brain tissue. Conclusion NDS could significantly reduce brain injury induced by global ischemia, and its mechanism is closely associated with anti-oxidation and anti-inflammation.展开更多
BACKGROUND: Restraint stress is a typical psychophysiological stressor. Simulating the early passion and difficulty in walking of patients after attack of stroke meets onset features.OBJECTIVE: To evaluate the effec...BACKGROUND: Restraint stress is a typical psychophysiological stressor. Simulating the early passion and difficulty in walking of patients after attack of stroke meets onset features.OBJECTIVE: To evaluate the effect of restraint stress on depression-like behaviors in rats after transient focal cerebral ischemic injury, and to investigate the feasibility for its being as modeling method of depression model after stroke.DESIGN: A randomized controlled animal experiment.SETTING: Department of Clinical Medicine, Faculty of Aerospace Medicine of the Fourth Military Medical University of Chinese PLA.MATERIALS: Forty-eight male Sprague-Dawley rats, weighing 240 - 270 g, provided by the Experimental Animal Center of the Fourth Military Medical University of Chinese PLA were used in the current study.METHODS: The experiments were carried out in the Faculty of Aerospace Medicine of the Fourth Military Medical University of Chinese PLA between August 2005 and August 2006. ①Experiment intervention: The rats were randomized into middle cerebral artery occlusion-reperfusion (MCAO) +stress group, simple MCAO group, sham-operation + stress group and simple sham-operation group, with 12 rats in each group.Rats in the first two groups were developed into cerebral ischemia/reperfusion models by suture-occluded method. Rats in the MCAO+stress group were modeled and restraint stress scheme was performed. At week 5 after modeling, the rats were placed in self-made restraining tubes, 2 hours/time, once a day, for 2 successive weeks. The common carotid artery, external and internal carotid arteries of rats in the latter two groups were exposed. The stress way of sham-operation+ stress group was the same as that of MCAO+ stress group. ②The neurological status grading and motor performance evaluation (screen test, rota-rod test and balance beam test) were conducted in rats with simple sham-operation group and MCAO group before, 1st and 28^th days after modeling. Depression-like behavior test was performed in the rats of each group by sucrose preference test and open field test at the end of the experiment.MAIN OUTCOME MEASURES: Changes of depression-like behaviors of rats in each group.RESULTS: Forty-eight rats were involved in the experiment. Two rats with meningeal irritation sign were excluded from simple MCAO group, and one rat in the MCAO+stress group died of some unclear causes during the experiments. The other 45 rats entered the stage of finial analysis. ① Depression-like behavior assessment results: The rats in the MCAO+ stress group had a significantly decreased preference for sucrose solution, crossing and rearing scores, and increased immobility duration after the 14-day restraint stress,compared with those in other three groups (all P〈0.05). ②The neurological status grading and motor performance evaluation: There were significant differences in the two indexes of rats in the simple MCAO group before, 1^st and 28^th days after modeling (P〈0.01), while there was no significant difference before and 28^th days after modeling (P〉0.05). There were no significant changes in sham-operation group at each time point (P〉0.05).CONCLUSION: After being exerted restraint stress, the rats with transient focal ischemic injury may show obvious depression-like behaviors. Therefore, restraint stress can be used as a novel animal modeling method for further studying biological mechanism in central nervous system of post-stroke depression animals.展开更多
Quercetin(QE; 3,5,7,3′,4′-pentahydroxyflavone), a well-known flavonoid, has been shown to prevent against neurodegenerative disorders and ischemic insults. However, few studies are reported regarding the neuroprot...Quercetin(QE; 3,5,7,3′,4′-pentahydroxyflavone), a well-known flavonoid, has been shown to prevent against neurodegenerative disorders and ischemic insults. However, few studies are reported regarding the neuroprotective mechanisms of QE after ischemic insults. Therefore, in this study, we investigated the effects of QE on ischemic injury and the expression of antioxidant enzymes in the hippocampal CA1 region of gerbils subjected to 5 minutes of transient cerebral ischemia. QE was pre-treated once daily for 15 days before ischemia. Pretreatment with QE protected hippocampal CA1 pyramidal neurons from ischemic injury, which was confirmed by neuronal nuclear antigen immunohistochemistry and Fluoro-Jade B histofluorescence staining. In addition, pretreatment with QE significantly increased the expression levels of endogenous antioxidant enzymes Cu/Zn superoxide dismutase, Mn superoxide dismutase, catalase and glutathione peroxidase in the hippocampal CA1 pyramidal neurons of animals with ischemic injury. These findings demonstrate that pretreated QE displayed strong neuroprotective effects against transient cerebral ischemia by increasing the expression of antioxidant enzymes.展开更多
Neuroprotection by ischemic preconditioning has been confirmed by many studies, but the precise mechanism remains unclear. In the present study, we performed cerebral ischemic pre- conditioning in rats by simulating a...Neuroprotection by ischemic preconditioning has been confirmed by many studies, but the precise mechanism remains unclear. In the present study, we performed cerebral ischemic pre- conditioning in rats by simulating a transient ischemic attack twice (each a 20-minute occlusion of the middle cerebral artery) before inducing focal cerebral infarction (2 hour occlusion-reper- fusion in the same artery). We also explored the mechanism underlying the neuroprotective effect of ischemic preconditioning. Seven days after ocdusion-reperfusion, tetrazolium chloride staining and immunohistochemistry revealed that the infarct volume was significantly smaller in the group that underwent preconditioning than in the model group. Furthermore, vascular endothelial growth factor immunoreactivity was considerably greater in the hippocampal CA3 region of preconditioned rats than model rats. Our results suggest that the protective effects of ischemic preconditioning on focal cerebral infarction are associated with upregulation of vascu- lar endothelial growth factor.展开更多
基金the Natural Science Foundation of LiaoningProvince, No. 619019
文摘BACKGROUND: Immediate early gene (lEG) c-jun is a sensitive marker for functional status of nerve cells. Caspase-3 is a cysteine protease, which is a critical regulator of apoptosis. The effect of exogenous nerve growth factor (NGF) on the expression of c-jun mRNA and Caspase-3 protein in striate cortex of rats with transient global cerebral ischemia/reperfusion (IR) is unclear. OBJECTIVE: To study the protective effect of exogenous NGF on the brain of rats with transient globa cerebral IR and its effecting pathway by observing the expression of c-jun mRNA and Caspase-3 protein. DESIGN: Randomized controlled animal trial SETTING: Department of Neural Anatomy, Institute of Brain, China Medical University MATERIALS:Eighteen healthy male SD rats of clean grade, aged 1 to 3 months, with body mass of 250 to 300 g, were involved in this study. NGF was provided by Dalian Svate Pharmaceutical Co.,Ltd. c-jun in situ hybridization detection kit, Caspase-3 antibody and SABC kit were purchased from Boster Biotechnology Co.. Ltd. METHODS: This trial was carried out in the Department of Neural Anatomy, Institute of Brain, China Medical University during September 2003 to April 2005. (1) Experimental animals were randomized into three groups with 6 in each: sham-operation group, IR group and NGF group.(2)After the rats were anesthetized, the bilateral common carotid arteries and right external carotid arteries of rats were bluntly dissected and bilateral common carotid arteries were clamped for 30 minutes with bulldog clamps. Reperfusion began after buldog clamps were removed. Normal saline of lmL and NGF (1×10^6 U/L) of 1 mL was injected into the common carotid artery of rats via right external carotid arteries in the IR group and NGF group respectively. The injection was conducted within 30 minutes, and then the right external carotid arteries were ligated. In the sham-operation group, occlusion of bilateral common carotid arteries and administration of drugs were omitted.GAll the rats were executed by decollation at 3 hours after modeling. The animals were fixed with phosphate buffer solution (PBS, 0.1 mol/L) containing 40 g/L polyformaldehyde, their brains were quickly removed. The coronal section tissue mass containing striate cortex about 3 mm before line between two ears was taken and made into successive frozen sections.(4)The expression of c-jun mRNA and Caspase-3 protein in striate cortex of global cerebral ischemia rats were detected with in situ hybridization, immunohistochemistry and microscope image analysis. (5)t test was used for comparing the difference of the measurement data. MAIN OUTCOME MEASURES:Comparison of the expression of lEG c-jun mRNA and Caspase-3 protein in striate cortex of brain of rats in each group. RESULTS:All the 18 SD rats were involved in the analysis of results. The c-jun mRNA and Caspase-3 protein positive reaction cells were found brown yellow in the striate cortex of rats, and most of them were in lamellas Ⅱ and Ⅲ, mainly presenting round or oval. The expression of c-jun mRNA and Caspase-3 protein in sham-operation group was weak or negative. The average gray value of c-jun mRNA and Caspase-3 protein in the IR group was significantly lower than that in the sham-operation group (49.52±4.13 vs. 95.48± 5.28; 74.73±4.29 vs. 162.38±9.16,P 〈 0.01). The average gray value of c-jun mRNA and Caspase-3 protein in the NGF group was significantly higher than that in the IR group (63.96±4.25 vs.49.52±4.13; 83.98± 4.13 vs. 74.73±4.29, P〈 0.05). CONCLUSION: NGF can protect ischemic neurons by down-regulating the expression of c-jun mRNA and Caspase-3 protein in striate cortex of global cerebral ischemia rats.
基金supported by the National Natural Science Foundation of China,No.82101567Doctoral Start-up Foundation of Liaoning Province,No.2021-BS-111345 Talent Project of Shengjing Hospital of China Medical University,No.M0673(all to XYF)。
文摘Cerebral ischemia/reperfusion injury impairs learning and memory in patients.Studies have shown that synaptic function is involved in the formation and development of memory,and that DNA methylation plays a key role in the regulation of learning and memory.To investigate the role of DNA hypomethylation in cerebral ischemia/reperfusion injury,in this study,we established a rat model of cerebral ischemia/reperfusion injury by occlusion of the middle cerebral artery and then treated the rats with intraperitoneal 5-aza-2′-deoxycytidine,an inhibitor of DNA methylation.Our results showed that 5-aza-2′-deoxycytidine markedly improved the neurological function,and cognitive,social and spatial memory abilities,and dose-dependently increased the synaptic density and the expression of SYP and SHANK2 proteins in the hippocampus in a dose-dependent manner in rats with cerebral ischemia/reperfusion injury.The effects of 5-aza-2′-deoxycytidine were closely related to its reduction of genomic DNA methylation and DNA methylation at specific sites of the Syp and Shank2 genes in rats with cerebral ischemia/reperfusion injury.These findings suggest that inhibition of DNA methylation by 5-aza-2′-deoxycytidine promotes the recovery of learning and memory impairment in a rat model of cerebral ischemia/reperfusion injury.These results provide theoretical evidence for stroke treatment using epigenetic methods.
基金Supported by the National Natural Science Foundation of China(Nos.30973110 81072071)+2 种基金the International Cooperation Grant(No.20070721)the Outstanding Youth Grant from the Science and Technology Department of Jilin ProvinceChina (No.20080139)
文摘Proteasome activity reduction is an important pathological phenomenon, resulting in proteins aggregation and neuronal death in the injured neurons induced by transient ischemia. Our previous report showed that the trap of proteasome in the protein aggregates was a reason to lead to the reduction of proteasome activity. However, the patterns of proteasome entered into protein aggregates are not clear. In this study, we used a global ischemia model, Hematoxylin-Eosin staining, differential centrifuge, proteasome activity assay, sucrose gradient density centrifuge, and Western blot analysis to investigate this problem. Our results show that there are two aggregation patterns of proteasome after transient ischemia and reperfusion. One is that 26S proteasome is trapped by protein aggregates as a whole unit, and the other is that 19S or 20S is trapped in the protein aggregates, respectively, after 26S disassociates.
基金Supported by:the Postdoctoral Foundation of China,No.20080440422International Cooperation G rant,No.20070721+1 种基金Outstanding Youth Grant of the Science and Technology Department of Jilin Province, No.20080139a grant from the Science and Technology Department of Changchun City,No.2007128
文摘BACKGROUND: Proteasome dysfunction has been reported to induce abnormal protein aggregation and cell death. OBJECTIVE: To investigate the effect of proteasome changes on delayed neuronal death in CA1 and dentate gyrus (DG) regions of the rat hippocampus following transient cerebral ischemia. DESIGN, TIME AND SETTING: A randomized, controlled animal experiment. The study was performed at the Department of Biochemistry and Molecular Biology, Norman Bethune Medical College of Jilin University, from September 2006 to May 2008. MATERIALS: Rabbit anti-19S S10B polyclonal antibody was purchased from Bioreagents, USA; propidium iodide and fluorescently-labeled goat anti-rabbit IgG were purchased from Jackson Immunoresearch, USA; hematoxylin and eosin staining solution was purchased from Sigma, USA; LSM 510 confocal microscope was purchased from Zeiss, Germany. METHODS: A total of 40 healthy Wistar rats, male, 4 months old, were randomly divided into sham surgery group (n = 8) and model group (n = 32). Ischemic models were established in the model group by transient clamping of the bilateral carotid arteries and decreased blood pressure. After 20 minutes of global ischemia, the clamp was removed to allow blood flow for 30 minutes, 4, 24 and 72 hours, respectively, with 8 rats at each time point. The bilateral carotid arteries were not ligated in the sham surgery group. MAIN OUTCOME MEASURES: Neuronal death in the CA1 and DG regions was observed by hematoxylin-eosin staining. Proteasome expression in CA1 and DG region neurons was detected by immunohistochemistry. RESULTS: Hematoxylin-eosin staining showed neuronal death in the CA1 region alone at 72 hours of reperfusion following ischemia. In comparison to the sham surgery group, a significant decrease in proteasome expression was observed, by immunohistochemistry, in the CA1 and DG regions in the model group, following 30 minutes, 4, 24, and 72 hours of reperfusion (P 〈 0.01). After 72 hours of reperfusion following ischemia, proteasome expression had almost completely disappeared in the CA1 region. In contrast, neurons of the DG region showed minimized proteasome expression at 24 hours, with a slight increase at 72 hours (P 〈 0.01). CONCLUSION: The alteration of proteasome following ischemia/reperfusion in the neurons of hippocampal CA1 and DG regions reduces the ability of cells to degrade abnormal protein, which may be an important factor resulting in delayed neuronal death following transient cerebral ischemia.
基金supported by the National Natural Science Foundation of China(No.81574048 and No.81904268)Key personnel training project of Health Care in middle-aged and young people in Fujian province(No.2019-ZQN-81).
文摘ATP depletion is one of the pathological bases in cerebral ischemia.Electro-acupuncture(EA)is widely used in clinical practice for ischemia.However,the mechanism of EA remains unclear.The purpose of this study was to investigate whether EA could activate the AMPK/PGC-1α/TFAM signaling pathway and,consequently,increase the preservation of ATP in rats with ischemia.In this study,48 rats were randomly divided into four groups as a sham-operation control group(sham group),a middle cerebral artery occlusion group(MCAO group),an EA group,and an EA group blocked by the AMPK inhibitor compound C(EA+CC group)(N=12/group).The rats of the EA group and EA+CC group received the EA treatment for 7 days.The rats that belonged in the two remaining groups were only grasped in the same condition.Then,their brain tissues were collected for further detection.When compared with other groups,EA significantly reduced neurological deficits score and increased motor function.The cerebral infarction volume was significantly reduced in the EA group according to TTC staining.With western blot,we found that EA improved the ratio of p-AMPKα/AMPKα(P<0.05),however,there is no difference between the MCAO group and sham group(P>0.05).In addition,EA also increased the expression of PGC-1αand TFAM(all P<0.05).By Elisa,we observed that EA increased the preservation of ATP(P<0.05)and mitochondrial respiratory enzymes,including Complex I(P<0.05),Complex IV(P<0.05),but not Complex III(P>0.05).In summary,we conclude that EA may protect against ischemic damage in MCAO rats,improve the preservation of ATP and mitochondrial respiratory enzymes.This effect may be positively regulated by the activation of the PGC-1α/TFAM signaling pathway.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(NRF-2017R1D1A1B03033271,to JDK)the Bio-Synergy Research Project(NRF-2018M3A9C4076478,to IJK)of the Ministry of Science,ICT and Future Planning through the National Research Foundation
文摘Recently,we have reported that Oenanthe javanica extract(OJE)displays strong neuroprotective effect against ischemic damage after transient global cerebral ischemia.However,neuroprotective mechanisms of OJE have not been fully identified.Thus,this study investigated the neuroprotection of OJE in the hippocampal CA1 area and its anti-inflammatory activity in gerbils subjected to 5 minutes of transient global cerebral ischemia.We treated the animals by intragastrical injection of OJE(100 and 200 mg/kg)once daily for 1 week prior to transient global cerebral ischemia.Neuroprotection of OJE was observed by immunohistochemistry for neuronal nuclear antigen and histofluorescence staining for Fluoro-Jade B.Immunohistochemistry of glial fibrillary acidic protein and ionized calcium-binding adapter molecule 1 was done for astrocytosis and microgliosis,respectively.To investigate the neuroprotective mechanisms of OJE,we performed immunohistochemistry of tumor necrosis factor-alpha and interleukin-2 for pro-inflammatory function and interleukin-4 and interleukin-13 for anti-inflammatory function.When we treated the animals by intragastrical administration of 200 mg/kg of OJE,hippocampal CA1 pyramidal neurons were protected from transient global cerebral ischemia and cerebral ischemia-induced gliosis was inhibited in the ischemic hippocampal CA1 area.We also found that interleukin-4 and-13 immunoreactivities were significantly increased in pyramidal neurons of the ischemic CA1 area after OJE pretreatment,and the increased immunoreactivities were sustained in the CA1 pyramidal neurons after transient global cerebral ischemia.However,OJE pretreatment did not increase interleukin-2 and tumor necrosis factor-alpha immunoreactivities in the CA1 pyramidal neurons.Our findings suggest that pretreatment with OJE can protect neurons and attenuate gliosis from transient global cerebral ischemia via increasing expressions of interleukin-4 and-13.The experimental plan of this study was reviewed and approved by the Institutional Animal Care and Use Committee(IACUC)in Kangwon National University(approval No.KW-160802-1)on August 10,2016.
基金supported by the Natural Science Foundation of Fujian Province of China,No.2014J01327the Program for New Century Excellent Talents in Colleges and Universities of Fujian Province of China,No.NCETFJ-0704the Professorial Academic Development Foundation of Fujian Medical University of China,No.JS09014(all to GYZ)
文摘Ilexonin A is a compound isolated from the root of Ilex pubescens,a traditional Chinese medicine.Ilexonin A has been shown to play a neuroprotective role by regulating the activation of astrocytes and microglia in the peri-infarct area after ischemia.However,the effects of ilexonin A on astrocytes and microglia in the infarct-free region of the hippocampal CA1 region remain unclear.Focal cerebral ischemia models were established by 2-hour occlusion of the middle cerebral artery in rats.Ilexonin A(20,40 or 80 mg/kg)was administered immediately after ischemia/reperfusion.The astrocyte marker glial fibrillary acidic protein,microglia marker Iba-1,neural stem cell marker nestin and inflammation markers were detected by immunohistochemistry and western blot assay.Expression levels of tumor necrosis factor-αand interleukin 1βwere determined by enzyme linked immunosorbent assay in the hippocampal CA1 tissue.Astrocytes were activated immediately in progressively increasing numbers from 1,3,to 7 days post-ischemia/reperfusion.The number of activated astrocytes further increased in the hippocampal CA1 region after treatment with ilexonin A.Microglial cells remained quiescent after ischemia/reperfusion,but became activated after treatment with ilexonin A.Ilexonin A enhanced nestin expression and reduced the expression of tumor necrosis factor-αand interleukin 1βin the hippocampus post-ischemia/reperfusion.The results of the present study suggest that ilexonin A has a neuroprotective effect in the hippocampus after ischemia/reperfusion,probably through regulating astrocytes and microglia activation,promoting neuronal stem cell proliferation and reducing the levels of pro-inflammatory factors.This study was approved by the Animal Ethics Committee of the Fujian Medical University Union Hospital,China.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Science,ICT and Future Planning(NRF-2013R1A2A2A01068190)Hallym University Specialization Fund(HRF-S-13)
文摘In this study, we tried to verify the neuroprotective effect of Chrysanthemum indicum Linne(CIL) extract, which has been used as a botanical drug in East Asia, against ischemic damage and to explore the underlying mechanism involving the anti-inflammatory approach. A gerbil was given CIL extract for 7 consecutive days followed by bilateral carotid artery occlusion to make a cerebral ischemia/reperfusion model. Then, we found that CIL extracts protected pyramidal neurons in the hippocampal CA1 region(CA1) from ischemic damage using neuronal nucleus immunohistochemistry and Fluoro-Jade B histofluorescence. Accordingly, interleukin-13 immunoreactivities in the CA1 pyramidal neurons of CIL-pretreated animals were maintained or increased after cerebral ischemia/reperfusion. These findings indicate that the pre-treatment of CIL can attenuate neuronal damage/death in the brain after cerebral ischemia/reperfusion via an anti-inflammatory approach.
基金supported by the Natural Science Foundation of Gansu Province,China,Nos.20JR5RA337(to BRH),20JR5RA336(to HJR)Cuiying Graduate Supervisor Applicant Training Program of Lanzhou University Second Hospital,China,No.CYDSPY201902(to BRH)+1 种基金Cuiying Students Research Ability Training Program of Lanzhou University Second Hospital,China,No.CYXZ2020-14(to BRH)Cuiying Scientific and Technological Innovation Program of Lanzhou University Second Hospital,China,No.CY2018-MS08(to BRH)。
文摘The survival of microglia depends on the colony-stimulating factor-1 receptor(CSF1R)signaling pathway under physiological conditions.Ki20227 is a highly selective CSF1R inhibitor that has been shown to change the morphology of microglia.However,the effects of Ki20227 on the progression of ischemic stroke are unclear.In this study,male C57 BL/6 mouse models of focal cerebral ischemic injury were established through the occlusion of the middle cerebral artery and then administered 3 mg/g Ki20227 for 3 successive days.The results revealed that the number of ionized calcium-binding adaptor molecule 1/bromodeoxyuridine double positive cells in the infarct tissue was reduced,the degree of edema was increased,neurological deficits were aggravated,infarct volume was increased,and the number of peri-infarct Nissl bodies was reduced.The number of terminal deoxynucleotidyl transferase dUTP nick-end labeling-positive cells in the peri-infarct tissue was increased.The expression levels of Bax and Cleaved caspase-3 were up-regulated.Bcl-2 expression was downregulated.The expression levels of inflammatory factors and oxidative stress-associated factors were increased.These findings suggested that Ki20227 blocked microglial proliferation and aggravated the pathological progression of ischemia/reperfusion injury in a transient middle cerebral artery occlusion model.This study was approved by the Animal Ethics Committee of Lanzhou University Second Hospital(approval No.D2020-68)on March 6,2020.
文摘Objective To investigate the therapeutic effect and possible mechanisms of Chinese ptent medicine Naodesheng(NDS) on repeated transient global cerebral ischemia(GCI) in mice. Methods The repeated transient GCI mice were induced by bilateral carotid arteries ligation, and were randomly divided into model group, Sham group without arteries ligation, NDS groups(1.25 and 2.5 g/kg) and positive control(vinpocetine 3.1 mg/kg, VP) group. After oral administration once daily for successive 7 d, the transient GCI was induced. The degree of neurological deficit, histological changes, and neurons loss in the hippocampus were evaluated. In order to investigate the possible mechanisms, the oxidative stress and inflammatory factor were measured after 24 h of GCI. Comparison among multiple groups was performed with one-way analysis of variance(ANOVA). Results NDS could significantly alleviate the neurological function impairment, histological injury, and neurons loss, increase the superoxide dismutase(SOD) activity, decrease the content of malondialdehyde(MDA), and reduce inflammatory factor in the ischemic brain tissue. Conclusion NDS could significantly reduce brain injury induced by global ischemia, and its mechanism is closely associated with anti-oxidation and anti-inflammation.
文摘BACKGROUND: Restraint stress is a typical psychophysiological stressor. Simulating the early passion and difficulty in walking of patients after attack of stroke meets onset features.OBJECTIVE: To evaluate the effect of restraint stress on depression-like behaviors in rats after transient focal cerebral ischemic injury, and to investigate the feasibility for its being as modeling method of depression model after stroke.DESIGN: A randomized controlled animal experiment.SETTING: Department of Clinical Medicine, Faculty of Aerospace Medicine of the Fourth Military Medical University of Chinese PLA.MATERIALS: Forty-eight male Sprague-Dawley rats, weighing 240 - 270 g, provided by the Experimental Animal Center of the Fourth Military Medical University of Chinese PLA were used in the current study.METHODS: The experiments were carried out in the Faculty of Aerospace Medicine of the Fourth Military Medical University of Chinese PLA between August 2005 and August 2006. ①Experiment intervention: The rats were randomized into middle cerebral artery occlusion-reperfusion (MCAO) +stress group, simple MCAO group, sham-operation + stress group and simple sham-operation group, with 12 rats in each group.Rats in the first two groups were developed into cerebral ischemia/reperfusion models by suture-occluded method. Rats in the MCAO+stress group were modeled and restraint stress scheme was performed. At week 5 after modeling, the rats were placed in self-made restraining tubes, 2 hours/time, once a day, for 2 successive weeks. The common carotid artery, external and internal carotid arteries of rats in the latter two groups were exposed. The stress way of sham-operation+ stress group was the same as that of MCAO+ stress group. ②The neurological status grading and motor performance evaluation (screen test, rota-rod test and balance beam test) were conducted in rats with simple sham-operation group and MCAO group before, 1st and 28^th days after modeling. Depression-like behavior test was performed in the rats of each group by sucrose preference test and open field test at the end of the experiment.MAIN OUTCOME MEASURES: Changes of depression-like behaviors of rats in each group.RESULTS: Forty-eight rats were involved in the experiment. Two rats with meningeal irritation sign were excluded from simple MCAO group, and one rat in the MCAO+stress group died of some unclear causes during the experiments. The other 45 rats entered the stage of finial analysis. ① Depression-like behavior assessment results: The rats in the MCAO+ stress group had a significantly decreased preference for sucrose solution, crossing and rearing scores, and increased immobility duration after the 14-day restraint stress,compared with those in other three groups (all P〈0.05). ②The neurological status grading and motor performance evaluation: There were significant differences in the two indexes of rats in the simple MCAO group before, 1^st and 28^th days after modeling (P〈0.01), while there was no significant difference before and 28^th days after modeling (P〉0.05). There were no significant changes in sham-operation group at each time point (P〉0.05).CONCLUSION: After being exerted restraint stress, the rats with transient focal ischemic injury may show obvious depression-like behaviors. Therefore, restraint stress can be used as a novel animal modeling method for further studying biological mechanism in central nervous system of post-stroke depression animals.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(NRF-2015R1D1A1A01059728)Hallym University Research Fund 2014(HURF-2014-25)
文摘Quercetin(QE; 3,5,7,3′,4′-pentahydroxyflavone), a well-known flavonoid, has been shown to prevent against neurodegenerative disorders and ischemic insults. However, few studies are reported regarding the neuroprotective mechanisms of QE after ischemic insults. Therefore, in this study, we investigated the effects of QE on ischemic injury and the expression of antioxidant enzymes in the hippocampal CA1 region of gerbils subjected to 5 minutes of transient cerebral ischemia. QE was pre-treated once daily for 15 days before ischemia. Pretreatment with QE protected hippocampal CA1 pyramidal neurons from ischemic injury, which was confirmed by neuronal nuclear antigen immunohistochemistry and Fluoro-Jade B histofluorescence staining. In addition, pretreatment with QE significantly increased the expression levels of endogenous antioxidant enzymes Cu/Zn superoxide dismutase, Mn superoxide dismutase, catalase and glutathione peroxidase in the hippocampal CA1 pyramidal neurons of animals with ischemic injury. These findings demonstrate that pretreated QE displayed strong neuroprotective effects against transient cerebral ischemia by increasing the expression of antioxidant enzymes.
文摘Neuroprotection by ischemic preconditioning has been confirmed by many studies, but the precise mechanism remains unclear. In the present study, we performed cerebral ischemic pre- conditioning in rats by simulating a transient ischemic attack twice (each a 20-minute occlusion of the middle cerebral artery) before inducing focal cerebral infarction (2 hour occlusion-reper- fusion in the same artery). We also explored the mechanism underlying the neuroprotective effect of ischemic preconditioning. Seven days after ocdusion-reperfusion, tetrazolium chloride staining and immunohistochemistry revealed that the infarct volume was significantly smaller in the group that underwent preconditioning than in the model group. Furthermore, vascular endothelial growth factor immunoreactivity was considerably greater in the hippocampal CA3 region of preconditioned rats than model rats. Our results suggest that the protective effects of ischemic preconditioning on focal cerebral infarction are associated with upregulation of vascu- lar endothelial growth factor.
文摘目的:探讨血清胱抑素C(Cystatin c,CysC)水平与短暂性脑缺血发作(Transient ischemic attack,TIA)患者颈内动脉狭窄的相关性.方法:纳入2019年1月至2022年6月我院收治的170例TIA患者为研究对象,根据脑血管造影检查结果评估颈动脉狭窄发生情况;并将颈动脉狭窄程度分为轻度狭窄组(n=38)、中度狭窄组(n=40)和重度狭窄组(n=41).收集所有患者基线资料,并在入院后测定患者实验室指标,重点分析血清CysC水平与TIA患者颈内动脉狭窄的相关性.结果:170例TIA患者中有119例患者发生颈动脉狭窄,发生率为70.00%,其中轻度狭窄患者38例,中度狭窄患者40例,重度狭窄患者41例;四组TIA患者性别、吸烟史、饮酒史、年龄、体重指数(Body Mass Index,BMI)、入院时美国国立卫生研究院卒中量表(National Institutes of Health Stroke Scale,NIHSS)评分、入院时收缩压(Systolic Blood Pressure,SBP)及入院时舒张压(Diastolic blood pressure,DBP)、血清总胆固醇(Cholesterol,CHO)水平比较,差异无统计学意义(P>0.05);重度狭窄组患者血清CysC水平均高于中度狭窄组及轻度狭窄组,三组间比较,差异有统计学意义(P<0.05).经Logistic回归分析显示,血清CysC水平升高是TIA患者颈动脉狭窄程度加重的风险因子(OR>1,P<0.05).结论:血清CysC水平与TIA患者颈内动脉狭窄密切相关,血清CysC水平升高会加重TIA患者颈内动脉狭窄程度.