Nonhuman primates are closest to humans in terms of lineage, and middle cerebral artery ischemia/reperfusion responses of nonhuman primates are most similar to ischemic stroke in humans. Therefore, nonhuman primates c...Nonhuman primates are closest to humans in terms of lineage, and middle cerebral artery ischemia/reperfusion responses of nonhuman primates are most similar to ischemic stroke in humans. Therefore, nonhuman primates could be utilized to simulate the process of ischemic stroke in the human. Few studies, however, have reported the use of endovascular technology to establish a rhesus monkey stroke model. In the present study, seven adult, male, rhesus monkeys were selected and, following anesthesia, a microcatheter was inserted into one side of the middle cerebral artery via the femoral artery to block blood flow, thereby resulting in middle cerebral artery occlusion. After 2 hours, the microcatheter was withdrawn to restore the middle cerebral artery blood flow and to establish ischemia/reperfusion. Results from angiography and magnetic resonance angiography confirmed occlusion and reopening of the middle cerebral artery. Magnetic resonance imaging revealed the existence of ischemic brain lesions, and neurological examination showed sustained functional deficits following surgery. The rhesus monkey middle cerebral artery ischemia/reperfusion models established by microcatheter embolization had the advantage of non-craniotomy invasion and reproducibility. The scope and degree of ischemic damage using this model was controllable. Therefore, this nonhuman primate model is an ideal model for cerebral ischemia and reperfusion.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
BACKGROUND: Insulin-like growth factor-I(IGF-1), as one of the important members of growth factor family, participants in the regulation of many physiological functions and behaviors, having very strong neuroprotec...BACKGROUND: Insulin-like growth factor-I(IGF-1), as one of the important members of growth factor family, participants in the regulation of many physiological functions and behaviors, having very strong neuroprotective effect. However, the expression of IGF-1 following cerebral ischemia/reperfusion is still disputed. OBJECTIVE: To observe the expression of IGF-1 and protein of corpora striata in ischemic side at the early stage of middle cerebral artery ischemia/reperfusion in rhesus monkey. DESIGN : A completely randomized grouping design, controlled animal experiment SETTING : Institute of Cerebrovascular Disease, Affiliated Hospital of Medical College of Qingdao University MATERIALS: ① Totally 17 rhesus monkeys , of either gender, aged 4 to 5 years, were enrolled . Seven rhesus monkeys observed with gene chip were randomly divided into 2 groups: sham operation group (n=3) and ischemia/reperfusion group 〈n=4〉. Ten rhesus monkeys observed with in situ hybridization and immunohistochemistry method were randomly divided into 2 groups: sham operation group 〈n=3 〉and ischemia/reperfusion group (n=7). Rhesus monkeys observed under microscope were divided into 2 groups: sham operation group (n=6) and ischamia/reperfusion group (n=-11).②Materials used in the experiment: cresyl violet (Sigma Company, America); immunohistochemical reagent kit ( Huamei Bio-engineering Company); In situ hybridization reagent kit (Boshide Bio-engineering Co.Ltd, Wuhan); 12 800 dots chip (Boxing Company, Shanghai). METHODS : This experiment was carried out at the Institute of Cerebrovascular Disease, Affiliated Hospital of Medical College of Qingdao University from January 2001 to December 2003.① The onset area of middle cerebral artery was blocked for 2 hours, middle cerebral artery ischemia/reperfusion models were created.② After ischemia/reperfusion for 24 hours, cerebral tissue sections of rhesus monkeys were prepared and stained with cresyl violet. Image analysis was performed with 5001W image analysis software. Morphological change of corpora striata of operative side was observed in the rhesus monkeys between two groups. Total RNA was extracted from cerebral tissue. ③ Detection of gene chip: Cy3-duTP and Cy5-duTP were used to respectively perform reverse transcription labeling. The sample was reversely transcribed into cDNA, then hybridized with cDNA of cerebral tissue. Genes with the separate absolute value of cy3 and cy5〉800, cY3/cy5 〉 2(high expression) or 〈 0.5 (low expression) were found out. Those were genes with differential expression. ④ The expressions of IGF-1 mRNA and protein level of corpora striata in ischemic side of rhe- sus monkeys were detected between sham operation group and ischemia/reperfusion group at 9 and 24 hours after ischemia/reperfusion with in situ hybridization method and immunohistochemical method. Brown granules were IGF-1 protein positive cells. ⑤ Analysis of variance was used in the difference comparison of measurement data among groups. MAIN OUTCOME MEASURES : ① Change of morphological structure of corpora striata at ischemic side in rhesus monkeys. ② Change of cerebral gene expression profiles at ischemia/reperfusion in rhesus monkeys between two groups.③ Expression of IGF-1 mRNA and protein level of corpora striata at ischemia/reperfu- sion in rhesus monkeys between two groups. RESULTS : ① Pathological change : Obvious pathological change of cerebral infarction appeared in the ischemia and reperfusion group, while there was no such pathological change in the sham operation group.② Change of gene expression profile : There were 4480 genes with difference expression in the ischemia/reperfusion group and sham-operation group, in which, 260 genes had high expression and their absolute value was over 800, and 63 genes had low expression, cy3/cy5 of IGF-1 was 0.379, being relative low ex- pression. ③ IGF-1 mRNA and protein positive cell counts in corpora striata at cerebral ischemic side[IGF-1 mRNA: 〈9.72±1.18),(9.11 ±0.76),(14.77±0.60) counts/field:lGF-1 protein: (15.11 ±1.83),(15.39±0.78), (34.62±0.97)counts/field, P 〈 0.05-0.01]. CONCLUSION: IGF-1 mRNA and protein are lowly expressed in middle cerebral artery of rhesus monkeys at ischemia/reperfusion.展开更多
Experimental stroke research commonly employs focal cerebral ischemic rat models (Bederson et al., 1986a; Longa et al., 1989). In human patients, ischemic stroke typically results from thrombotic or embolic occlusio...Experimental stroke research commonly employs focal cerebral ischemic rat models (Bederson et al., 1986a; Longa et al., 1989). In human patients, ischemic stroke typically results from thrombotic or embolic occlusion of a major cerebral artery, usually the mid- dle cerebral artery (MCA). Experimental focal cerebral ischemia models have been employed to mimic human stroke (Durukan and Tatlisumak, 2007). Rodent models of focal cerebral ischemia that do not require craniotomy have been developed using intraluminal suture occlusion of the MCA (MCA occlusion, MCAO) (Rosamond et al., 2008). Furthermore, mouse MCAO models have been wide- ly used and extended to genetic studies of cell death or recovery mechanisms (Liu and McCullough, 2011). Genetically engineered mouse stroke models are particularly useful for evaluation of isch- emic pathophysiology and the design of new prophylactic, neuro- protective, and therapeutic agents and interventions (Armstead et al., 2010). During the past two decades, MCAO surgical techniques have been developed that do not reveal surgical techniques for mouse MCAO model engineering. Therefore, we compared MCAO surgical methods in rats and mice.展开更多
Microglia,which are the resident macrophages of the central nervous system,are an important part of the inflammatory response that occurs after cerebral ischemia.Vav guanine nucleotide exchange factor 1(Vav1) is a gua...Microglia,which are the resident macrophages of the central nervous system,are an important part of the inflammatory response that occurs after cerebral ischemia.Vav guanine nucleotide exchange factor 1(Vav1) is a guanine nucleotide exchange factor that is related to microglial activation.However,how Vav1 participates in the inflammato ry response after cerebral ischemia/reperfusion inj ury remains unclea r.In this study,we subjected rats to occlusion and repe rfusion of the middle cerebral artery and subjected the BV-2 mic roglia cell line to oxygen-glucose deprivatio n/reoxygenation to mimic cerebral ischemia/repe rfusion in vivo and in vitro,respectively.We found that Vav1 levels were increased in the brain tissue of rats subjected to occlusion and reperfusion of the middle cerebral arte ry and in BV-2 cells subjected to oxygen-glucose deprivation/reoxygenation.Silencing Vav1 reduced the cerebral infarct volume and brain water content,inhibited neuronal loss and apoptosis in the ischemic penumbra,and im p roved neurological function in rats subjected to occlusion and repe rfusion of the middle cerebral artery.Further analysis showed that Vav1 was almost exclusively localized to microglia and that Vav1 downregulation inhibited microglial activation and the NOD-like receptor pyrin 3(NLRP3) inflammasome in the ischemic penumbra,as well as the expression of inflammato ry facto rs.In addition,Vov1 knoc kdown decreased the inflammatory response exhibited by BV-2 cells after oxygen-glucose deprivation/reoxyge nation.Taken together,these findings show that silencing Vav1 attenuates inflammation and neuronal apoptosis in rats subjected to cerebral ischemia/repe rfusion through inhibiting the activation of mic roglia and NLRP3 inflammasome.展开更多
In vivo imaging of cerebral ischemia/reperfusion injury remains an important challenge.We injected porous Ag/Au@SiO_(2) bimetallic hollow nanoshells carrying anti-tropomyosin 4 as a molecular probe into mice with cere...In vivo imaging of cerebral ischemia/reperfusion injury remains an important challenge.We injected porous Ag/Au@SiO_(2) bimetallic hollow nanoshells carrying anti-tropomyosin 4 as a molecular probe into mice with cerebral ischemia/reperfusion injury and observed microvascular changes in the brain using photoacoustic imaging with ultrasonography.At each measured time point,the total photoacoustic signal was significantly higher on the affected side than on the healthy side.Twelve hours after reperfusion,cerebral perfusion on the affected side increased,cerebrovascular injury worsened,and anti-tropomyosin 4 expression increased.Twenty-four hours after reperfusion and later,perfusion on the affected side declined slowly and stabilized after 1 week;brain injury was also alleviated.Histopathological and immunohistochemical examinations confirmed the brain injury tissue changes.The nanoshell molecular probe carrying anti-tropomyosin 4 has potential for use in early diagnosis of cerebral ischemia/reperfusion injury and evaluating its progression.展开更多
Aim Reduction of Sheng-Nao-Kang decoction (RSNK), is a modified traditional Chinese medicinal formula of Sheng-Nao-Kang pill preparation, which is protective in rats against focal cerebral ischemia/reperfusion (I/R...Aim Reduction of Sheng-Nao-Kang decoction (RSNK), is a modified traditional Chinese medicinal formula of Sheng-Nao-Kang pill preparation, which is protective in rats against focal cerebral ischemia/reperfusion (I/R) injury. In the current study, we investigate the protective effect of RSNK against apoptosis and oxidative damage induced by cerebral I/R and explore the underlying mechanisms. Cerebral I/R injury was induced by in- traluminal middle cerebral artery occlusion (MCAO) for 2 h followed by reperfusion for 24 h in adult male Sprague- Dawley rats. Rats were randomized into seven groups (n- 8): Sham group, I/R group, RSNK-treated groups ( 0.7 g · kg ^- 1, 1 . 4 g · kg ^- 1 and 2. 8 g · kg^ - 1 ) , nimodipine (NMP) -treated group and Whitmania pigra Whitman (WW)-treated group. Neurological deficit scores, cerebral humidity content and cerebral infarction volume were measured after the 24 h reperfusion. Malondialdehyde ( MDA), superoxide dismutase ( SOD), catalase ( CAT), inducible nitric oxide synthase (iNOS) and total nitric oxide synthase (TNOS) in serum were measured by assay kits for biochemical analysis. Histological structures of the cortex of the ipsilateral ischemic cerebral hemisphere in rats were observed by Nissl staining. The caspase-3 protein content in the hippocampus and cortex was detected by immunohistochemistry. Additionally, Bax and Bcl-2 protein expressions in the injured brain were evaluated by Western blot. RSNK administration not only markedly improved neurological deficit scores, but also reduced cere- bral humidity content and cerebral infarction volume, lowered MDA content, up-regulated SOD and CAT levels, down-regulated iNOS and TNOS levels, restrained the expression of caspase-3 positive protein and alleviated the Bax and Bcl-2 protein expressions.展开更多
The purpose of this work was to demonstrate the feasibility of neurite orientation dispersion and density imaging(NODDI)in characterizing the brain tissue microstructural changes of middle cerebral artery occlusion(MC...The purpose of this work was to demonstrate the feasibility of neurite orientation dispersion and density imaging(NODDI)in characterizing the brain tissue microstructural changes of middle cerebral artery occlusion(MCAO)in rats at 3T MRI,and to validate NODDI metrics with histology.A multi-shell diffusion MRI protocol was performed on 11 MCAO rats and 10 control rats at different post-operation time points of 0.5,2,6,12,24 and 72 h.NODDI orientation dispersion index(ODI)and intracellular volume fraction(V_(ic))metrics were compared between MCAO group and control group.The evolution of NODDI metrics was characterized and validated by histology.Infarction was consistent with significantly increased ODI and V_(ic)in comparison to control tissues at all time points(P<0.001).Lesion ODI increased gradually from 0.5 to 72 h,while its V_(ic)showed a more complicated and fluctuated evolution.ODI and V_(ic)were significantly different between hyperacute and acute stroke periods(P<0.001).The NODDI metrics were found to be consistent with the histological findings.In conclusion,NODDI can reflect microstructural changes of brain tissues in MCAO rats at 3T MRI and the metrics are consistent with histology.This study helps to prepare NODDI for the diagnosis and management of ischemic stroke in translational research and clinical practice.展开更多
Puerarin, a traditional Chinese medicine, exerts a powerful neuroprotective effect in cerebral ischemia/reperfusion injury, but its mechanism is unknown. Here, we established rat models of middle cerebral artery ische...Puerarin, a traditional Chinese medicine, exerts a powerful neuroprotective effect in cerebral ischemia/reperfusion injury, but its mechanism is unknown. Here, we established rat models of middle cerebral artery ischemia/reperfusion injury using the suture method. Puerarin (100 mg/kg) was administered intraperitoneally 30 minutes before middle cerebral artery occlusion and 8 hours after reperfusion. Twenty-four hours after reperfusion, we found that puerarin significantly improved neurological deficit, reduced infarct size and brain water content, and notably diminished the expression of Toll-like receptor-4, myeloid differentiation factor 88, nuclear factor kappa B and tumor necrosis factor-α in the ischemic region. These data indicate that puerarin exerts an anti-inflammatory protective effect on brain tissue with ischemia/reperfusion damage by downregulating the expression of multiple inflammatory factors.展开更多
Heat-sensitive suspended moxibustion has a neuroprotective effect against focal cerebral ischemia/reperfusion injury, but the underly- ing mechanisms remain unclear. The duration of heat-sensitive suspended moxibusti...Heat-sensitive suspended moxibustion has a neuroprotective effect against focal cerebral ischemia/reperfusion injury, but the underly- ing mechanisms remain unclear. The duration of heat-sensitive suspended moxibustion (usually from 30 minutes to 1 hour) is longer than traditional suspended moxibustion (usually 15 minutes). However, the effects of 15- and 35-minute suspended moxibustion in rats with cerebra/ischemia/reperfusion injury are poorly understood. In this study, we performed 15- or 35-minute suspended moxibustion at acupoint Dazhui (GV14) in an adult rat model of focal cerebral ischemia/reperfusion injury. Infarct volume was evaluated with the 2,3,5-triphenyltetrazolium chloride assay. Histopathological changes and neuronal apoptosis at the injury site were assessed by hematoxy- lin-eosin staining and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Caspase-9 and caspase-3 expression at the in- jury site was detected using immunofluorescent staining. Bax and Bcl-2 expression at the injury site was assessed using western blot assay. In the 35-minute moxibustion group, infarct volume was decreased, neuronal apoptosis was reduced, caspase-9, caspase-3 and Bax expres- sion was lower, and Bcl-2 expression was increased, compared with the 15-minute moxibustion group. Our findings show that 35-minute moxibustion has a greater anti-apoptotic effect than 15-minute moxibustion after focal cerebral ischemia/reperfusion injury.展开更多
The present study aimed to explore the mechanism underlying the protective effects of hydrogen sulfide against neuronal damage caused by cerebral ischemia/reperfusion. We established the middle cerebral artery occlusi...The present study aimed to explore the mechanism underlying the protective effects of hydrogen sulfide against neuronal damage caused by cerebral ischemia/reperfusion. We established the middle cerebral artery occlusion model in rats via the suture method. Ten minutes after middle cerebral artery occlusion, the animals were intraperitoneally injected with hydrogen sulfide donor compound sodium hydrosulfide. Immunofluorescence revealed that the immunoreactivity of P2X7 in the cerebral cortex and hippocampal CA1 region in rats with cerebral ischemia/reperfusion injury decreased with hydrogen sulfide treatment. Furthermore, treatment of these rats with hydrogen sulfide significantly lowered mortality, the Longa neurological deficit scores, and infarct volume. These results indicate that hydrogen sulfide may be protective in rats with local cerebral ischemia/reperfusion injury by down-regulating the expression of P2X7 receptors.展开更多
Reperfusion therapy is the preferred treatment for ischemic stroke,but is hindered by its short treatment window,especially in patients with diabetes whose reperfusion after prolonged ischemia is often accompanied by ...Reperfusion therapy is the preferred treatment for ischemic stroke,but is hindered by its short treatment window,especially in patients with diabetes whose reperfusion after prolonged ischemia is often accompanied by exacerbated hemorrhage.The mechanisms underlying exacerbated hemorrhage are not fully understood.This study aimed to identify this mechanism by inducing prolonged 2-hour transient intraluminal middle cerebral artery occlusion in diabetic Ins2Akita/+mice to mimic patients with diabetes undergoing delayed mechanical thrombectomy.The results showed that at as early as 2 hours after reperfusion,Ins2Akita/+mice exhibited rapid development of neurological deficits,increased infarct and hemorrhagic transformation,together with exacerbated down-regulation of tight-junction protein ZO-1 and upregulation of blood-brain barrier-disrupting matrix metallopeptidase 2 and matrix metallopeptidase 9 when compared with normoglycemic Ins2+/+mice.This indicated that diabetes led to the rapid compromise of vessel integrity immediately after reperfusion,and consequently earlier death and further aggravation of hemorrhagic transformation 22 hours after reperfusion.This observation was associated with earlier and stronger up-regulation of pro-angiogenic vascular endothelial growth factor(VEGF)and its downstream phospho-Erk1/2 at 2 hours after reperfusion,which was suggestive of premature angiogenesis induced by early VEGF up-regulation,resulting in rapid vessel disintegration in diabetic stroke.Endoplasmic reticulum stress-related pro-apoptotic C/EBP homologous protein was overexpressed in challenged Ins2Akita/+mice,which suggests that the exacerbated VEGF up-regulation may be caused by overwhelming endoplasmic reticulum stress under diabetic conditions.In conclusion,the results mimicked complications in patients with diabetes undergoing delayed mechanical thrombectomy,and diabetes-induced accelerated VEGF up-regulation is likely to underlie exacerbated hemorrhagic transformation.Thus,suppression of the VEGF pathway could be a potential approach to allow reperfusion therapy in patients with diabetic stroke beyond the current treatment window.Experiments were approved by the Committee on the Use of Live Animals in Teaching and Research of the University of Hong Kong[CULATR 3834-15(approval date January 5,2016);3977-16(approval date April 13,2016);and 4666-18(approval date March 29,2018)].展开更多
Gelatinases matrix metalloproteinase-2 and matrix metalloproteinase-9 have been shown to mediate claudin-5 and occludin degradation, and play an important regulatory role in blood-brain barrier permeability. This stud...Gelatinases matrix metalloproteinase-2 and matrix metalloproteinase-9 have been shown to mediate claudin-5 and occludin degradation, and play an important regulatory role in blood-brain barrier permeability. This study established a rat model of 1.5-hour middle cerebral artery occlusion with reperfusion. Protein expression levels of claudin-5 and occludin gradually decreased in the early stage of reperfusion, which corresponded to the increase of the gelatinolytic activity of matrix metalloproteinase-2 and matrix metalloproteinase-9. In addition, rats that received treatment with matrix metalloproteinase inhibitor N-[(2R)-2-(hydroxamidocarbonylmethyl)-4-methylpenthanoyl]-L- tryptophan methylamide (GM6001) showed a significant reduction in Evans blue leakage and an inhibition of claudin-5 and occludin protein degradation in striatal tissue. These data indicate that matrix metalloproteinase-2 and matrix metalloproteinase-9-mediated claudin-5 and occludin degradation is an important reason for blood-brain barrier leakage in the early stage of reperfusion. The leakage of the blood-brain barrier was present due to gelatinases-mediated degradation of claudin-5 and occludin proteins. We hypothesized that the timely closure of the structural component of the blood-brain barrier (tight junction proteins) is of importance.展开更多
Objective To study the protective effect of agrimony extracts from different extracting methods on cerebral ischemia-reperfusion injury in rats, in order to optimize the extraction scheme of agrimony.Methods Male rats...Objective To study the protective effect of agrimony extracts from different extracting methods on cerebral ischemia-reperfusion injury in rats, in order to optimize the extraction scheme of agrimony.Methods Male rats were randomly assigned into seven groups: 1. Sham-operated group, 2. Untreated MCAO group (MCAO), 3. Petroleum ether extract of Agrimonia pilosa treated MCAO group (PEA), 4. Ethyl acetate extract of Agrimonia pilosa treated MCAO group (EAEA), 5. Ethanol extract of Agrimonia pilosa treated MCAO group (EEA), 6. Water extract of Agrimonia pilosa treated MCAO group (WEA), 7. Nimodipine treated MCAO group (NP). Intragastrical drug administration (i.g) was performed at 0 and 6 hours after MCAO.Neurological function tests were performed after reperfusion for 24 hours, then the brain was removed for the evaluations of the cerebral infarction volume (percentage of total brain volume) by immunohistochemistry,histological changes (hematoxylin-eosin staining), Na+/K+-ATPase, Ca2+-ATPase (modified method of Svoboda and Mosinger), mRNA expression of Tumor suppressor gene (P53) and hot shock protein (HSP70)(quantitative real-time PCR).Results The neurological function of MCAO group had significantly higher scores than the sham group (P<0.01). The WEA group showed a significantly lower neurological score than the MCAO group (P<0.05),indicating the protective effect of WEA on neurological deficits. The mean infarction volumes of WEA (13.5±6.6%, F=4.75, P<0.01), EEA (19.90±6.90%, F=5.23, P<0.01), PEA (20.40±5.30%, F=4.68,P<0.01) and EAEA (22.50±10.50%, F=6.25, P<0.05) group were all significantly smaller than that of MCAO group (29.40±6.50%). HE staining demonstrated that, compared to the treated groups, the infarcted cerebral tissue of MCAO group had more swelling neural cells, lighter stained nucleus, fewer and irregularly distributed neurons. The activity of Na+/K+-ATPase and Ca2+-ATPase reduced in the MCAO group (3.67±0.48 U/mg,1.28±0.26 U/mg, respectively), and were significantly higher in WEA group (7.56±0.85 U/mg, F=12.65,P=0.010; 3.59±0.22 U/mg, F=8.32, P=0.041, respectively). The MCAO group showed significantly elevated P53 and HSP70 mRNA expressions compared to the sham group (P<0.01, P<0.05). P53 mRNA expressions in Agrimony extracts treated groups were significantly lower than that of the MCAO group (all P<0.01), with the WEA group showing the greatest difference from MCAO group. The HSP70 mRNA level of the treated groups were not significantly different from that of the MCAO group.Conclusions Treatment using water extracts of agrimony can promote the best functional and metabolic recovery for rat model of cerebral ischemia-reperfusion injury, which maybe relate with the upregulation of energy metabolism in nerve cells after MCAO.展开更多
Penehyclidine hydrochloride can promote microcirculation and reduce vascular permeability. However, the role of penehyclidine hydrochlodde in cerebral ischemia-reperfusion injury remains unclear. In this study, in viv...Penehyclidine hydrochloride can promote microcirculation and reduce vascular permeability. However, the role of penehyclidine hydrochlodde in cerebral ischemia-reperfusion injury remains unclear. In this study, in vivo middle cerebral artery occlusion models were established in experimental rats, and penehyclidine hydrochloride pretreatment was given via intravenous injection prior to model establishment. Tetrazolium chloride, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling and immunohistochemical staining showed that, penehyclidine hydrochloride pretreatment markedly attenuated neuronal histopathological changes in the cortex, hippocampus and striatum, reduced infarction size, increased the expression level of BcI-2, decreased the expression level of caspase-3, and inhibited neuronal apoptosis in rats with cerebral ischemia-reperfusion injury. Xanthine oxidase and thiobarbituric acid chromogenic results showed that penehyclidine hydrochloride upregulated the activity of superoxide dismutase and downregulated the concentration of malondialdehyde in the ischemic cerebral cortex and hippocampus, as well as reduced the concentration of extracellular excitatory amino acids in rats with cerebral ischemia-reperfusion injury. In addition, penehyclidine hydrochloride inhibited the expression level of the NR1 subunit in hippocampal nerve cells in vitro following oxygen-glucose deprivation, as detected by PCR. Experimental findings indicate that penehyclidine hydrochloride attenuates neuronal apoptosis and oxidative stress injury after focal cerebral ischemia-reperfusion, thus exerting a neuroprotective effect.展开更多
Ischemic stroke is universally acknowledged as a common cause of long-term disability or even death. Suspended moxibustion, an indirect form of moxibustion, is when moxibustion is placed superficially over the skin wi...Ischemic stroke is universally acknowledged as a common cause of long-term disability or even death. Suspended moxibustion, an indirect form of moxibustion, is when moxibustion is placed superficially over the skin without being in contact with it. Some researchers have used this method to treat stroke patients, but strong evidence of its therapeutic effectiveness is lacking. However, the effect of traditional suspended moxibustion has recently been improved with the development of heat-sensitive suspended moxibustion. Our previous studies showed that moxibustion for 35 min provided a more effective treatment strategy than moxibustion for 15 min, and moxibustion by 35 min with tail temperature increase had a better outcome than that without, however, the mechanism underlying the effect is not clear. In this study, we treated the stroke rats with moxibustion by 35min and divided them into non-heat sensitive moxibustion(NHSM) group and heat sensitive moxibustion (HSM) group according to difference in the tail temperature increase, then we compared the effect and investigated the mechanisms between NHSM and HSM. We found that HSM significantly decreased tail-flick latency, increased neurological function score, decreased infarct volume, reduced inflammatory cells, decreased the expression of inflammatory factor ICAM-1 and reduced the expression of NF-κB p65 and p-IKKα/β in rats with focal cerebral ischemia/reperfusion injury. Our experimental findings revealed that HSM exerted its anti-inflammatory and neuroprotective effects from MCAO-induced injury by decreasing the expression of the NF-κB signaling pathway.展开更多
Rodents have been widely used in the production of cerebral ischemia models. However, successful therapies have been proven on experimental rodent stroke model, and they have often failed to be effective when tested c...Rodents have been widely used in the production of cerebral ischemia models. However, successful therapies have been proven on experimental rodent stroke model, and they have often failed to be effective when tested clinically. Therefore, nonhuman primates were recommended as the ideal alternatives, owing to their similarities with the human cerebrovascular system, brain metabolism, grey to white matter ratio and even their rich behavioral repertoire. The present review is a thorough summary of ten methods that establish nonhuman primate models of focal cerebral ischemia; electrocoagulation, endothelin-1-induced occlusion, microvascular clip occlusion, autologous blood clot embolization, balloon inflation, microcatheter embolization, coil embolization, surgical suture embolization, suture, and photochemical induction methods. This review addresses the advantages and disadvantages of each method, as well as precautions for each model, compared nonhuman primates with rodents, different species of nonhuman primates and different modeling methods. Finally it discusses various factors that need to be considered when modelling and the method of evaluation after modelling. These are critical for understanding their respective strengths and weaknesses and underlie the selection of the optimum model.展开更多
Angiopoietin-1/tyrosine kinase with immunoglobulin and epidermal growth factor homology domains 2 (Tie-2) is a newly discovered signaling pathway of angiogenesis. Angiogenesis benefits recovery of neurological funct...Angiopoietin-1/tyrosine kinase with immunoglobulin and epidermal growth factor homology domains 2 (Tie-2) is a newly discovered signaling pathway of angiogenesis. Angiogenesis benefits recovery of neurological functions such as swallowing. In the present study, a rat model of dysphagia following stroke was induced by middle cerebral artery occlusion to investigate the influence of low frequency electrical stimulus with bidirectional square waves and triangular waves on angiopoietin-1/-13e-2 mRNA expression. Reverse transcription-polymerase chain reaction results showed that low frequency electrical stimulus significantly improved the neurological scores of the model rats, and increased angiopoietin-1/'13e-2 mRNA expression. This demonstrates that low frequency electrical stimulation can ameliorate neurological function in rats with focal brain ischemia, potentially through regulation of angiopoietin-1/-13e-2 expression in the angiogenesis pathway.展开更多
Puerarin suppresses autophagy to alleviate cerebral ischemia/reperfusion injury, and accumulating evidence indicates that the AMPKm TOR signaling pathway regulates the activation of the autophagy pathway through the c...Puerarin suppresses autophagy to alleviate cerebral ischemia/reperfusion injury, and accumulating evidence indicates that the AMPKm TOR signaling pathway regulates the activation of the autophagy pathway through the coordinated phosphorylation of ULK1. In this study, we investigated the mechanisms underlying the neuroprotective effect of puerarin and its role in modulating autophagy via the AMPK-m TOR-ULK1 signaling pathway in the rat middle cerebral artery occlusion model of cerebral ischemia/reperfusion injury. Rats were intraperitoneally injected with puerarin, 50 or 100 mg/kg, daily for 7 days. Then, 30 minutes after the final administration, rats were subjected to transient middle cerebral artery occlusion for 90 minutes. Then, after 24 hours of reperfusion, the Longa score and infarct volume were evaluated in each group. Autophagosome formation was observed by transmission electron microscopy. LC3, Beclin-1 p62, AMPK, m TOR and ULK1 protein expression levels were examined by immunofluorescence and western blot assay. Puerarin substantially reduced the Longa score and infarct volume, and it lessened autophagosome formation in the hippocampal CA1 area following cerebral ischemia/reperfusion injury in a dose-dependent manner. Pretreatment with puerarin(50 or 100 mg/kg) reduced Beclin-1 expression and the LC3-II/LC3-I ratio, as well as p-AMPK and p S317-ULK1 levels. In comparison, it increased p62 expression. Furthermore, puerarin at 100 mg/kg dramatically increased the levels of p-m TOR and p S757-ULK1 in the hippocampus on the ischemic side. Our findings suggest that puerarin alleviates autophagy by activating the APMK-m TOR-ULK1 signaling pathway. Thus, puerarin might have therapeutic potential for treating cerebral ischemia/reperfusion injury.展开更多
Some scholars have recently developed the concept of PANoptosis in the study of infectious diseases where pyroptosis,apoptosis and necroptosis act in consort in a multimeric protein complex,PANoptosome.This allows all...Some scholars have recently developed the concept of PANoptosis in the study of infectious diseases where pyroptosis,apoptosis and necroptosis act in consort in a multimeric protein complex,PANoptosome.This allows all the components of PANoptosis to be regulated simultaneously.PANoptosis provides a new way to study the regulation of cell death,in that different types of cell death may be regulated at the same time.To test whether PANoptosis exists in diseases other than infectious diseases,we chose cerebral ischemia/reperfusion injury as the research model,collected articles researching cerebral ischemia/reperfusion from three major databases,obtained the original research data from these articles by bibliometrics,data mining and other methods,then integrated and analyzed these data.We selected papers that investigated at least two of the components of PANoptosis to check its occurrence in ischemia/reperfusion.In the cell model simulating ischemic brain injury,pyroptosis,apoptosis and necroptosis occur together and this phenomenon exists widely in different passage cell lines or primary neurons.Pyroptosis,apoptosis and necroptosis also occurred in rat and mouse models of ischemia/reperfusion injury.This confirms that PANoptosis is observed in ischemic brain injury and indicates that PANoptosis can be a target in the regulation of various central nervous system diseases.展开更多
基金the National High Technology Program of China,No.2006AA02A117
文摘Nonhuman primates are closest to humans in terms of lineage, and middle cerebral artery ischemia/reperfusion responses of nonhuman primates are most similar to ischemic stroke in humans. Therefore, nonhuman primates could be utilized to simulate the process of ischemic stroke in the human. Few studies, however, have reported the use of endovascular technology to establish a rhesus monkey stroke model. In the present study, seven adult, male, rhesus monkeys were selected and, following anesthesia, a microcatheter was inserted into one side of the middle cerebral artery via the femoral artery to block blood flow, thereby resulting in middle cerebral artery occlusion. After 2 hours, the microcatheter was withdrawn to restore the middle cerebral artery blood flow and to establish ischemia/reperfusion. Results from angiography and magnetic resonance angiography confirmed occlusion and reopening of the middle cerebral artery. Magnetic resonance imaging revealed the existence of ischemic brain lesions, and neurological examination showed sustained functional deficits following surgery. The rhesus monkey middle cerebral artery ischemia/reperfusion models established by microcatheter embolization had the advantage of non-craniotomy invasion and reproducibility. The scope and degree of ischemic damage using this model was controllable. Therefore, this nonhuman primate model is an ideal model for cerebral ischemia and reperfusion.
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the Natural Science Foundation of Shandong Province, No. Y2004C04
文摘BACKGROUND: Insulin-like growth factor-I(IGF-1), as one of the important members of growth factor family, participants in the regulation of many physiological functions and behaviors, having very strong neuroprotective effect. However, the expression of IGF-1 following cerebral ischemia/reperfusion is still disputed. OBJECTIVE: To observe the expression of IGF-1 and protein of corpora striata in ischemic side at the early stage of middle cerebral artery ischemia/reperfusion in rhesus monkey. DESIGN : A completely randomized grouping design, controlled animal experiment SETTING : Institute of Cerebrovascular Disease, Affiliated Hospital of Medical College of Qingdao University MATERIALS: ① Totally 17 rhesus monkeys , of either gender, aged 4 to 5 years, were enrolled . Seven rhesus monkeys observed with gene chip were randomly divided into 2 groups: sham operation group (n=3) and ischemia/reperfusion group 〈n=4〉. Ten rhesus monkeys observed with in situ hybridization and immunohistochemistry method were randomly divided into 2 groups: sham operation group 〈n=3 〉and ischemia/reperfusion group (n=7). Rhesus monkeys observed under microscope were divided into 2 groups: sham operation group (n=6) and ischamia/reperfusion group (n=-11).②Materials used in the experiment: cresyl violet (Sigma Company, America); immunohistochemical reagent kit ( Huamei Bio-engineering Company); In situ hybridization reagent kit (Boshide Bio-engineering Co.Ltd, Wuhan); 12 800 dots chip (Boxing Company, Shanghai). METHODS : This experiment was carried out at the Institute of Cerebrovascular Disease, Affiliated Hospital of Medical College of Qingdao University from January 2001 to December 2003.① The onset area of middle cerebral artery was blocked for 2 hours, middle cerebral artery ischemia/reperfusion models were created.② After ischemia/reperfusion for 24 hours, cerebral tissue sections of rhesus monkeys were prepared and stained with cresyl violet. Image analysis was performed with 5001W image analysis software. Morphological change of corpora striata of operative side was observed in the rhesus monkeys between two groups. Total RNA was extracted from cerebral tissue. ③ Detection of gene chip: Cy3-duTP and Cy5-duTP were used to respectively perform reverse transcription labeling. The sample was reversely transcribed into cDNA, then hybridized with cDNA of cerebral tissue. Genes with the separate absolute value of cy3 and cy5〉800, cY3/cy5 〉 2(high expression) or 〈 0.5 (low expression) were found out. Those were genes with differential expression. ④ The expressions of IGF-1 mRNA and protein level of corpora striata in ischemic side of rhe- sus monkeys were detected between sham operation group and ischemia/reperfusion group at 9 and 24 hours after ischemia/reperfusion with in situ hybridization method and immunohistochemical method. Brown granules were IGF-1 protein positive cells. ⑤ Analysis of variance was used in the difference comparison of measurement data among groups. MAIN OUTCOME MEASURES : ① Change of morphological structure of corpora striata at ischemic side in rhesus monkeys. ② Change of cerebral gene expression profiles at ischemia/reperfusion in rhesus monkeys between two groups.③ Expression of IGF-1 mRNA and protein level of corpora striata at ischemia/reperfu- sion in rhesus monkeys between two groups. RESULTS : ① Pathological change : Obvious pathological change of cerebral infarction appeared in the ischemia and reperfusion group, while there was no such pathological change in the sham operation group.② Change of gene expression profile : There were 4480 genes with difference expression in the ischemia/reperfusion group and sham-operation group, in which, 260 genes had high expression and their absolute value was over 800, and 63 genes had low expression, cy3/cy5 of IGF-1 was 0.379, being relative low ex- pression. ③ IGF-1 mRNA and protein positive cell counts in corpora striata at cerebral ischemic side[IGF-1 mRNA: 〈9.72±1.18),(9.11 ±0.76),(14.77±0.60) counts/field:lGF-1 protein: (15.11 ±1.83),(15.39±0.78), (34.62±0.97)counts/field, P 〈 0.05-0.01]. CONCLUSION: IGF-1 mRNA and protein are lowly expressed in middle cerebral artery of rhesus monkeys at ischemia/reperfusion.
基金supported by the 2013 Inje University Research Grant
文摘Experimental stroke research commonly employs focal cerebral ischemic rat models (Bederson et al., 1986a; Longa et al., 1989). In human patients, ischemic stroke typically results from thrombotic or embolic occlusion of a major cerebral artery, usually the mid- dle cerebral artery (MCA). Experimental focal cerebral ischemia models have been employed to mimic human stroke (Durukan and Tatlisumak, 2007). Rodent models of focal cerebral ischemia that do not require craniotomy have been developed using intraluminal suture occlusion of the MCA (MCA occlusion, MCAO) (Rosamond et al., 2008). Furthermore, mouse MCAO models have been wide- ly used and extended to genetic studies of cell death or recovery mechanisms (Liu and McCullough, 2011). Genetically engineered mouse stroke models are particularly useful for evaluation of isch- emic pathophysiology and the design of new prophylactic, neuro- protective, and therapeutic agents and interventions (Armstead et al., 2010). During the past two decades, MCAO surgical techniques have been developed that do not reveal surgical techniques for mouse MCAO model engineering. Therefore, we compared MCAO surgical methods in rats and mice.
基金Natural Science Foundation of Liaoning Province (General Program),No.2017010825 (to JQ)。
文摘Microglia,which are the resident macrophages of the central nervous system,are an important part of the inflammatory response that occurs after cerebral ischemia.Vav guanine nucleotide exchange factor 1(Vav1) is a guanine nucleotide exchange factor that is related to microglial activation.However,how Vav1 participates in the inflammato ry response after cerebral ischemia/reperfusion inj ury remains unclea r.In this study,we subjected rats to occlusion and repe rfusion of the middle cerebral artery and subjected the BV-2 mic roglia cell line to oxygen-glucose deprivatio n/reoxygenation to mimic cerebral ischemia/repe rfusion in vivo and in vitro,respectively.We found that Vav1 levels were increased in the brain tissue of rats subjected to occlusion and reperfusion of the middle cerebral arte ry and in BV-2 cells subjected to oxygen-glucose deprivation/reoxygenation.Silencing Vav1 reduced the cerebral infarct volume and brain water content,inhibited neuronal loss and apoptosis in the ischemic penumbra,and im p roved neurological function in rats subjected to occlusion and repe rfusion of the middle cerebral artery.Further analysis showed that Vav1 was almost exclusively localized to microglia and that Vav1 downregulation inhibited microglial activation and the NOD-like receptor pyrin 3(NLRP3) inflammasome in the ischemic penumbra,as well as the expression of inflammato ry facto rs.In addition,Vov1 knoc kdown decreased the inflammatory response exhibited by BV-2 cells after oxygen-glucose deprivation/reoxyge nation.Taken together,these findings show that silencing Vav1 attenuates inflammation and neuronal apoptosis in rats subjected to cerebral ischemia/repe rfusion through inhibiting the activation of mic roglia and NLRP3 inflammasome.
基金supported by the National Natural Science Foundation of China,No.81730050(to WH).
文摘In vivo imaging of cerebral ischemia/reperfusion injury remains an important challenge.We injected porous Ag/Au@SiO_(2) bimetallic hollow nanoshells carrying anti-tropomyosin 4 as a molecular probe into mice with cerebral ischemia/reperfusion injury and observed microvascular changes in the brain using photoacoustic imaging with ultrasonography.At each measured time point,the total photoacoustic signal was significantly higher on the affected side than on the healthy side.Twelve hours after reperfusion,cerebral perfusion on the affected side increased,cerebrovascular injury worsened,and anti-tropomyosin 4 expression increased.Twenty-four hours after reperfusion and later,perfusion on the affected side declined slowly and stabilized after 1 week;brain injury was also alleviated.Histopathological and immunohistochemical examinations confirmed the brain injury tissue changes.The nanoshell molecular probe carrying anti-tropomyosin 4 has potential for use in early diagnosis of cerebral ischemia/reperfusion injury and evaluating its progression.
文摘Aim Reduction of Sheng-Nao-Kang decoction (RSNK), is a modified traditional Chinese medicinal formula of Sheng-Nao-Kang pill preparation, which is protective in rats against focal cerebral ischemia/reperfusion (I/R) injury. In the current study, we investigate the protective effect of RSNK against apoptosis and oxidative damage induced by cerebral I/R and explore the underlying mechanisms. Cerebral I/R injury was induced by in- traluminal middle cerebral artery occlusion (MCAO) for 2 h followed by reperfusion for 24 h in adult male Sprague- Dawley rats. Rats were randomized into seven groups (n- 8): Sham group, I/R group, RSNK-treated groups ( 0.7 g · kg ^- 1, 1 . 4 g · kg ^- 1 and 2. 8 g · kg^ - 1 ) , nimodipine (NMP) -treated group and Whitmania pigra Whitman (WW)-treated group. Neurological deficit scores, cerebral humidity content and cerebral infarction volume were measured after the 24 h reperfusion. Malondialdehyde ( MDA), superoxide dismutase ( SOD), catalase ( CAT), inducible nitric oxide synthase (iNOS) and total nitric oxide synthase (TNOS) in serum were measured by assay kits for biochemical analysis. Histological structures of the cortex of the ipsilateral ischemic cerebral hemisphere in rats were observed by Nissl staining. The caspase-3 protein content in the hippocampus and cortex was detected by immunohistochemistry. Additionally, Bax and Bcl-2 protein expressions in the injured brain were evaluated by Western blot. RSNK administration not only markedly improved neurological deficit scores, but also reduced cere- bral humidity content and cerebral infarction volume, lowered MDA content, up-regulated SOD and CAT levels, down-regulated iNOS and TNOS levels, restrained the expression of caspase-3 positive protein and alleviated the Bax and Bcl-2 protein expressions.
基金National Natural Science Foundation of China(No.81570462,No.81730049,and No.81801666).
文摘The purpose of this work was to demonstrate the feasibility of neurite orientation dispersion and density imaging(NODDI)in characterizing the brain tissue microstructural changes of middle cerebral artery occlusion(MCAO)in rats at 3T MRI,and to validate NODDI metrics with histology.A multi-shell diffusion MRI protocol was performed on 11 MCAO rats and 10 control rats at different post-operation time points of 0.5,2,6,12,24 and 72 h.NODDI orientation dispersion index(ODI)and intracellular volume fraction(V_(ic))metrics were compared between MCAO group and control group.The evolution of NODDI metrics was characterized and validated by histology.Infarction was consistent with significantly increased ODI and V_(ic)in comparison to control tissues at all time points(P<0.001).Lesion ODI increased gradually from 0.5 to 72 h,while its V_(ic)showed a more complicated and fluctuated evolution.ODI and V_(ic)were significantly different between hyperacute and acute stroke periods(P<0.001).The NODDI metrics were found to be consistent with the histological findings.In conclusion,NODDI can reflect microstructural changes of brain tissues in MCAO rats at 3T MRI and the metrics are consistent with histology.This study helps to prepare NODDI for the diagnosis and management of ischemic stroke in translational research and clinical practice.
基金supported by the Chinese Traditional Medical Science Foundation of Zhejiang Province in China,No.2010ZA072the Health Bureau Foundation of Zhejiang Province in China,No.2012ZDA023the Qianjiang Project of Zhejiang Science and Technology Bureau in China,No.2010 R10073
文摘Puerarin, a traditional Chinese medicine, exerts a powerful neuroprotective effect in cerebral ischemia/reperfusion injury, but its mechanism is unknown. Here, we established rat models of middle cerebral artery ischemia/reperfusion injury using the suture method. Puerarin (100 mg/kg) was administered intraperitoneally 30 minutes before middle cerebral artery occlusion and 8 hours after reperfusion. Twenty-four hours after reperfusion, we found that puerarin significantly improved neurological deficit, reduced infarct size and brain water content, and notably diminished the expression of Toll-like receptor-4, myeloid differentiation factor 88, nuclear factor kappa B and tumor necrosis factor-α in the ischemic region. These data indicate that puerarin exerts an anti-inflammatory protective effect on brain tissue with ischemia/reperfusion damage by downregulating the expression of multiple inflammatory factors.
基金supported by the National Natural Science Foundation of China,No.81060305&81660819the Natural Science Foundation of Jiangxi Province of China,No.2015BAB205068+2 种基金Key Program for Science and Technology Cooperation Projects of Jiangxi Province of China,No.20161BBH80053a grant from the Key Project of Health Commission of Jiangxi Province of China,No.2014Z003the Natural Science Foundation of Jiangxi University of Traditional Chinese Medicine of China,No.2014ZR018&2015jzzdxk024
文摘Heat-sensitive suspended moxibustion has a neuroprotective effect against focal cerebral ischemia/reperfusion injury, but the underly- ing mechanisms remain unclear. The duration of heat-sensitive suspended moxibustion (usually from 30 minutes to 1 hour) is longer than traditional suspended moxibustion (usually 15 minutes). However, the effects of 15- and 35-minute suspended moxibustion in rats with cerebra/ischemia/reperfusion injury are poorly understood. In this study, we performed 15- or 35-minute suspended moxibustion at acupoint Dazhui (GV14) in an adult rat model of focal cerebral ischemia/reperfusion injury. Infarct volume was evaluated with the 2,3,5-triphenyltetrazolium chloride assay. Histopathological changes and neuronal apoptosis at the injury site were assessed by hematoxy- lin-eosin staining and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Caspase-9 and caspase-3 expression at the in- jury site was detected using immunofluorescent staining. Bax and Bcl-2 expression at the injury site was assessed using western blot assay. In the 35-minute moxibustion group, infarct volume was decreased, neuronal apoptosis was reduced, caspase-9, caspase-3 and Bax expres- sion was lower, and Bcl-2 expression was increased, compared with the 15-minute moxibustion group. Our findings show that 35-minute moxibustion has a greater anti-apoptotic effect than 15-minute moxibustion after focal cerebral ischemia/reperfusion injury.
基金financially supported by grants from the National Natural Science Foundation of China,No.81371346,81271376Outstanding Postgraduate Fund of Xinxiang Medical UniversityScience and Technology Key Research Project of Henan Provincial Education Department of China,No.14A310019
文摘The present study aimed to explore the mechanism underlying the protective effects of hydrogen sulfide against neuronal damage caused by cerebral ischemia/reperfusion. We established the middle cerebral artery occlusion model in rats via the suture method. Ten minutes after middle cerebral artery occlusion, the animals were intraperitoneally injected with hydrogen sulfide donor compound sodium hydrosulfide. Immunofluorescence revealed that the immunoreactivity of P2X7 in the cerebral cortex and hippocampal CA1 region in rats with cerebral ischemia/reperfusion injury decreased with hydrogen sulfide treatment. Furthermore, treatment of these rats with hydrogen sulfide significantly lowered mortality, the Longa neurological deficit scores, and infarct volume. These results indicate that hydrogen sulfide may be protective in rats with local cerebral ischemia/reperfusion injury by down-regulating the expression of P2X7 receptors.
基金supported by Health and Medical Research Fund,the Food and Health Bureau,The Government of the Hong Kong Special Administrative Region(03142256)General Research Fund,Hong Kong Research Grants Council(GRF#HKU773613M)+1 种基金Seed Funding Programme for Basic Research(201811159123,201910159191)The University of Hong Kong(all to ACYL)。
文摘Reperfusion therapy is the preferred treatment for ischemic stroke,but is hindered by its short treatment window,especially in patients with diabetes whose reperfusion after prolonged ischemia is often accompanied by exacerbated hemorrhage.The mechanisms underlying exacerbated hemorrhage are not fully understood.This study aimed to identify this mechanism by inducing prolonged 2-hour transient intraluminal middle cerebral artery occlusion in diabetic Ins2Akita/+mice to mimic patients with diabetes undergoing delayed mechanical thrombectomy.The results showed that at as early as 2 hours after reperfusion,Ins2Akita/+mice exhibited rapid development of neurological deficits,increased infarct and hemorrhagic transformation,together with exacerbated down-regulation of tight-junction protein ZO-1 and upregulation of blood-brain barrier-disrupting matrix metallopeptidase 2 and matrix metallopeptidase 9 when compared with normoglycemic Ins2+/+mice.This indicated that diabetes led to the rapid compromise of vessel integrity immediately after reperfusion,and consequently earlier death and further aggravation of hemorrhagic transformation 22 hours after reperfusion.This observation was associated with earlier and stronger up-regulation of pro-angiogenic vascular endothelial growth factor(VEGF)and its downstream phospho-Erk1/2 at 2 hours after reperfusion,which was suggestive of premature angiogenesis induced by early VEGF up-regulation,resulting in rapid vessel disintegration in diabetic stroke.Endoplasmic reticulum stress-related pro-apoptotic C/EBP homologous protein was overexpressed in challenged Ins2Akita/+mice,which suggests that the exacerbated VEGF up-regulation may be caused by overwhelming endoplasmic reticulum stress under diabetic conditions.In conclusion,the results mimicked complications in patients with diabetes undergoing delayed mechanical thrombectomy,and diabetes-induced accelerated VEGF up-regulation is likely to underlie exacerbated hemorrhagic transformation.Thus,suppression of the VEGF pathway could be a potential approach to allow reperfusion therapy in patients with diabetic stroke beyond the current treatment window.Experiments were approved by the Committee on the Use of Live Animals in Teaching and Research of the University of Hong Kong[CULATR 3834-15(approval date January 5,2016);3977-16(approval date April 13,2016);and 4666-18(approval date March 29,2018)].
文摘Gelatinases matrix metalloproteinase-2 and matrix metalloproteinase-9 have been shown to mediate claudin-5 and occludin degradation, and play an important regulatory role in blood-brain barrier permeability. This study established a rat model of 1.5-hour middle cerebral artery occlusion with reperfusion. Protein expression levels of claudin-5 and occludin gradually decreased in the early stage of reperfusion, which corresponded to the increase of the gelatinolytic activity of matrix metalloproteinase-2 and matrix metalloproteinase-9. In addition, rats that received treatment with matrix metalloproteinase inhibitor N-[(2R)-2-(hydroxamidocarbonylmethyl)-4-methylpenthanoyl]-L- tryptophan methylamide (GM6001) showed a significant reduction in Evans blue leakage and an inhibition of claudin-5 and occludin protein degradation in striatal tissue. These data indicate that matrix metalloproteinase-2 and matrix metalloproteinase-9-mediated claudin-5 and occludin degradation is an important reason for blood-brain barrier leakage in the early stage of reperfusion. The leakage of the blood-brain barrier was present due to gelatinases-mediated degradation of claudin-5 and occludin proteins. We hypothesized that the timely closure of the structural component of the blood-brain barrier (tight junction proteins) is of importance.
基金Fund supported by National Science Foundation of China (NSFC) 81503491,81374053, 81630105.
文摘Objective To study the protective effect of agrimony extracts from different extracting methods on cerebral ischemia-reperfusion injury in rats, in order to optimize the extraction scheme of agrimony.Methods Male rats were randomly assigned into seven groups: 1. Sham-operated group, 2. Untreated MCAO group (MCAO), 3. Petroleum ether extract of Agrimonia pilosa treated MCAO group (PEA), 4. Ethyl acetate extract of Agrimonia pilosa treated MCAO group (EAEA), 5. Ethanol extract of Agrimonia pilosa treated MCAO group (EEA), 6. Water extract of Agrimonia pilosa treated MCAO group (WEA), 7. Nimodipine treated MCAO group (NP). Intragastrical drug administration (i.g) was performed at 0 and 6 hours after MCAO.Neurological function tests were performed after reperfusion for 24 hours, then the brain was removed for the evaluations of the cerebral infarction volume (percentage of total brain volume) by immunohistochemistry,histological changes (hematoxylin-eosin staining), Na+/K+-ATPase, Ca2+-ATPase (modified method of Svoboda and Mosinger), mRNA expression of Tumor suppressor gene (P53) and hot shock protein (HSP70)(quantitative real-time PCR).Results The neurological function of MCAO group had significantly higher scores than the sham group (P<0.01). The WEA group showed a significantly lower neurological score than the MCAO group (P<0.05),indicating the protective effect of WEA on neurological deficits. The mean infarction volumes of WEA (13.5±6.6%, F=4.75, P<0.01), EEA (19.90±6.90%, F=5.23, P<0.01), PEA (20.40±5.30%, F=4.68,P<0.01) and EAEA (22.50±10.50%, F=6.25, P<0.05) group were all significantly smaller than that of MCAO group (29.40±6.50%). HE staining demonstrated that, compared to the treated groups, the infarcted cerebral tissue of MCAO group had more swelling neural cells, lighter stained nucleus, fewer and irregularly distributed neurons. The activity of Na+/K+-ATPase and Ca2+-ATPase reduced in the MCAO group (3.67±0.48 U/mg,1.28±0.26 U/mg, respectively), and were significantly higher in WEA group (7.56±0.85 U/mg, F=12.65,P=0.010; 3.59±0.22 U/mg, F=8.32, P=0.041, respectively). The MCAO group showed significantly elevated P53 and HSP70 mRNA expressions compared to the sham group (P<0.01, P<0.05). P53 mRNA expressions in Agrimony extracts treated groups were significantly lower than that of the MCAO group (all P<0.01), with the WEA group showing the greatest difference from MCAO group. The HSP70 mRNA level of the treated groups were not significantly different from that of the MCAO group.Conclusions Treatment using water extracts of agrimony can promote the best functional and metabolic recovery for rat model of cerebral ischemia-reperfusion injury, which maybe relate with the upregulation of energy metabolism in nerve cells after MCAO.
文摘Penehyclidine hydrochloride can promote microcirculation and reduce vascular permeability. However, the role of penehyclidine hydrochlodde in cerebral ischemia-reperfusion injury remains unclear. In this study, in vivo middle cerebral artery occlusion models were established in experimental rats, and penehyclidine hydrochloride pretreatment was given via intravenous injection prior to model establishment. Tetrazolium chloride, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling and immunohistochemical staining showed that, penehyclidine hydrochloride pretreatment markedly attenuated neuronal histopathological changes in the cortex, hippocampus and striatum, reduced infarction size, increased the expression level of BcI-2, decreased the expression level of caspase-3, and inhibited neuronal apoptosis in rats with cerebral ischemia-reperfusion injury. Xanthine oxidase and thiobarbituric acid chromogenic results showed that penehyclidine hydrochloride upregulated the activity of superoxide dismutase and downregulated the concentration of malondialdehyde in the ischemic cerebral cortex and hippocampus, as well as reduced the concentration of extracellular excitatory amino acids in rats with cerebral ischemia-reperfusion injury. In addition, penehyclidine hydrochloride inhibited the expression level of the NR1 subunit in hippocampal nerve cells in vitro following oxygen-glucose deprivation, as detected by PCR. Experimental findings indicate that penehyclidine hydrochloride attenuates neuronal apoptosis and oxidative stress injury after focal cerebral ischemia-reperfusion, thus exerting a neuroprotective effect.
基金We would like to thank the National Natural Science Foun dation of China (81060305, 81660819)the Natural Science Foundation of Jiangxi Province (20151BAB205068), Key Project of Health Commission of Jiangxi province (2014Z003)Natural Science Foundation of Jiangxi University of Traditional Chinese Medicine (2014ZR018,- 2015jzzdxk024) for their supports.
文摘Ischemic stroke is universally acknowledged as a common cause of long-term disability or even death. Suspended moxibustion, an indirect form of moxibustion, is when moxibustion is placed superficially over the skin without being in contact with it. Some researchers have used this method to treat stroke patients, but strong evidence of its therapeutic effectiveness is lacking. However, the effect of traditional suspended moxibustion has recently been improved with the development of heat-sensitive suspended moxibustion. Our previous studies showed that moxibustion for 35 min provided a more effective treatment strategy than moxibustion for 15 min, and moxibustion by 35 min with tail temperature increase had a better outcome than that without, however, the mechanism underlying the effect is not clear. In this study, we treated the stroke rats with moxibustion by 35min and divided them into non-heat sensitive moxibustion(NHSM) group and heat sensitive moxibustion (HSM) group according to difference in the tail temperature increase, then we compared the effect and investigated the mechanisms between NHSM and HSM. We found that HSM significantly decreased tail-flick latency, increased neurological function score, decreased infarct volume, reduced inflammatory cells, decreased the expression of inflammatory factor ICAM-1 and reduced the expression of NF-κB p65 and p-IKKα/β in rats with focal cerebral ischemia/reperfusion injury. Our experimental findings revealed that HSM exerted its anti-inflammatory and neuroprotective effects from MCAO-induced injury by decreasing the expression of the NF-κB signaling pathway.
基金supported by the National Natural Science Foundation of China,No.81000852 and 81301677the AHA Award,No.17POST32530004+1 种基金the Supporting Project of Science & Technology of Sichuan Province of China,No.2012SZ0140the Research Foundation of Zhejiang Province of China,No.201022896
文摘Rodents have been widely used in the production of cerebral ischemia models. However, successful therapies have been proven on experimental rodent stroke model, and they have often failed to be effective when tested clinically. Therefore, nonhuman primates were recommended as the ideal alternatives, owing to their similarities with the human cerebrovascular system, brain metabolism, grey to white matter ratio and even their rich behavioral repertoire. The present review is a thorough summary of ten methods that establish nonhuman primate models of focal cerebral ischemia; electrocoagulation, endothelin-1-induced occlusion, microvascular clip occlusion, autologous blood clot embolization, balloon inflation, microcatheter embolization, coil embolization, surgical suture embolization, suture, and photochemical induction methods. This review addresses the advantages and disadvantages of each method, as well as precautions for each model, compared nonhuman primates with rodents, different species of nonhuman primates and different modeling methods. Finally it discusses various factors that need to be considered when modelling and the method of evaluation after modelling. These are critical for understanding their respective strengths and weaknesses and underlie the selection of the optimum model.
基金the National High-Tech R&D Program of China (863 Program), No.2007AA022Z482
文摘Angiopoietin-1/tyrosine kinase with immunoglobulin and epidermal growth factor homology domains 2 (Tie-2) is a newly discovered signaling pathway of angiogenesis. Angiogenesis benefits recovery of neurological functions such as swallowing. In the present study, a rat model of dysphagia following stroke was induced by middle cerebral artery occlusion to investigate the influence of low frequency electrical stimulus with bidirectional square waves and triangular waves on angiopoietin-1/-13e-2 mRNA expression. Reverse transcription-polymerase chain reaction results showed that low frequency electrical stimulus significantly improved the neurological scores of the model rats, and increased angiopoietin-1/'13e-2 mRNA expression. This demonstrates that low frequency electrical stimulation can ameliorate neurological function in rats with focal brain ischemia, potentially through regulation of angiopoietin-1/-13e-2 expression in the angiogenesis pathway.
基金supported by the National Natural Science Foundation of China,No.81202625the Open Fund of Key Laboratory of Cardiovascular and Cerebrovascular Diseases Translational Medicine,China Three Gorges University,China,No.2016xnxg101
文摘Puerarin suppresses autophagy to alleviate cerebral ischemia/reperfusion injury, and accumulating evidence indicates that the AMPKm TOR signaling pathway regulates the activation of the autophagy pathway through the coordinated phosphorylation of ULK1. In this study, we investigated the mechanisms underlying the neuroprotective effect of puerarin and its role in modulating autophagy via the AMPK-m TOR-ULK1 signaling pathway in the rat middle cerebral artery occlusion model of cerebral ischemia/reperfusion injury. Rats were intraperitoneally injected with puerarin, 50 or 100 mg/kg, daily for 7 days. Then, 30 minutes after the final administration, rats were subjected to transient middle cerebral artery occlusion for 90 minutes. Then, after 24 hours of reperfusion, the Longa score and infarct volume were evaluated in each group. Autophagosome formation was observed by transmission electron microscopy. LC3, Beclin-1 p62, AMPK, m TOR and ULK1 protein expression levels were examined by immunofluorescence and western blot assay. Puerarin substantially reduced the Longa score and infarct volume, and it lessened autophagosome formation in the hippocampal CA1 area following cerebral ischemia/reperfusion injury in a dose-dependent manner. Pretreatment with puerarin(50 or 100 mg/kg) reduced Beclin-1 expression and the LC3-II/LC3-I ratio, as well as p-AMPK and p S317-ULK1 levels. In comparison, it increased p62 expression. Furthermore, puerarin at 100 mg/kg dramatically increased the levels of p-m TOR and p S757-ULK1 in the hippocampus on the ischemic side. Our findings suggest that puerarin alleviates autophagy by activating the APMK-m TOR-ULK1 signaling pathway. Thus, puerarin might have therapeutic potential for treating cerebral ischemia/reperfusion injury.
基金supported by the National Natural Science Foundation of China,Nos.81772134(to KX),81971891(to KX),82172196(to KX),81571939(to KX)the Fundamental Research Funds for the Central Universities of Central South University of China,No.2020zzts218,(to WTY)Hunan Provincial Innovation Foundation For Postgraduate of China,Nos.CX20200116(to WTY),CX20190139(to LSL).
文摘Some scholars have recently developed the concept of PANoptosis in the study of infectious diseases where pyroptosis,apoptosis and necroptosis act in consort in a multimeric protein complex,PANoptosome.This allows all the components of PANoptosis to be regulated simultaneously.PANoptosis provides a new way to study the regulation of cell death,in that different types of cell death may be regulated at the same time.To test whether PANoptosis exists in diseases other than infectious diseases,we chose cerebral ischemia/reperfusion injury as the research model,collected articles researching cerebral ischemia/reperfusion from three major databases,obtained the original research data from these articles by bibliometrics,data mining and other methods,then integrated and analyzed these data.We selected papers that investigated at least two of the components of PANoptosis to check its occurrence in ischemia/reperfusion.In the cell model simulating ischemic brain injury,pyroptosis,apoptosis and necroptosis occur together and this phenomenon exists widely in different passage cell lines or primary neurons.Pyroptosis,apoptosis and necroptosis also occurred in rat and mouse models of ischemia/reperfusion injury.This confirms that PANoptosis is observed in ischemic brain injury and indicates that PANoptosis can be a target in the regulation of various central nervous system diseases.