OBJECTIVE URB597(KDS-4103)is a potent and selective inhibitor of the enzyme fatty acid amide hydrolase(FAAH)and can ele⁃vate the level of oleoylethanolamide(OEA),a naturally occurring endocannabinoid in the brain.Howe...OBJECTIVE URB597(KDS-4103)is a potent and selective inhibitor of the enzyme fatty acid amide hydrolase(FAAH)and can ele⁃vate the level of oleoylethanolamide(OEA),a naturally occurring endocannabinoid in the brain.However,the effect of URB597 on cerebral isch⁃emic injury in mice remains unclear.METHODS Focal cerebral ischemia was induced by middle cerebral artery occlusion for 30 min followed by reperfusion for 24 h in mice.To observe the dose-dependent effect,URB597(0.04-5.00 mg·kg-1,ip)was administered at the same time of reperfu⁃sion.To determine the time-dependent effect,URB597(1.00 mg·kg-1,ip)was administered as a single dose at 0,1,3 or 5 h after reperfusion.Twenty-four hours after brain ischemia,Beder⁃son scoring test and grip strength test were used to evaluate the neurological function;brain in⁃farct volume was assayed by 2,3,5-triphenyltetra⁃zolium chloride(TTC)staining or diffusion-weighted magnetic resonance imaging(MRI).Laser speckle imaging(LSI)technique was used to assay the regional cerebral blood flow(rCBF);NeuN immunofluorescence staining was used to observe the neuron survival in the penumbra.To further investigate the underlying mechanism,au⁃tophagy flux related proteins(LC3-Ⅱ,P62 and LAMP2)and necroptosis related proteins(pRIPK3 and pMLKL)were detected by Western blotting and immunofluorescence staining.RESULTS Twenty-four hours after brain ischemia,URB597 dose-dependently improved neurological func⁃tion and reduced brain infarct volume.The most effective dose was 1.00 mg·kg-1;the therapeutic time window was within 1 h after ischemic stroke.The protective effect is further confirmed by the results that post-ischemic treatment with URB597(1.00 mg·kg-1)significantly increased neurons survival,promoted autophagy flux and reduced cell necroptosis in cortical penumbra after cerebral I/R.CONCLUSION URB597 dose-and time-dependently exerts a neuroprotective effect against acute cerebral I/R injury.This neu⁃roprotective effect of URB597 may be associated with its restoration of autophagy flux and inhibi⁃tion of neuronal necroptosis in the cortical penumbra.展开更多
BACKGROUND: Adenovirus has been used to develop neuroglobin (Ngb) vectors. Although transfection efficiency is high, induced gene mutation, cytotoxicity, inflammation, and low exoge- nous gene content have limited its...BACKGROUND: Adenovirus has been used to develop neuroglobin (Ngb) vectors. Although transfection efficiency is high, induced gene mutation, cytotoxicity, inflammation, and low exoge- nous gene content have limited its application. OBJECTIVE: To observe the effects of recombinant Ngb plasmid in a rat model of focal cerebral ischemia. DESIGN, TIME AND SETTING: Genetically engineered, randomized, controlled, animal experiment was performed at the Laboratory of Chongqing Medical University from May 2006 and January 2007. MATERIALS: 2, 3, 5-triphenyltetrazolium chloride was purchased from Shanghai Sangon Biological Engineering Technology and Services. Rabbit anti-rat Bcl-2 polyclonal antibody, rabbit anti-rat β-actin monoclonal antibody, and FITC-labeled goat anti-rabbit IgG were purchased from Sigma, USA. TUNEL apoptosis kit was purchased from Roche, Germany. METHODS: A total of 54 male, adult, Wistar rats were randomly assigned to 3 groups (n = 18): normal saline, plasmid control, and recombinant Ngb (pCDNA3.1(+)/Ngb). Normal saline, plasmid pCDNA3.1(+), and recombinant plasmid pCDNA3.1(+)/Ngb were separately injected into two sites in the rat cerebral cortex, and models of focal ischemia were established by occlusion of the right middle cerebral artery after 24 hours. MAIN OUTCOME MEASURES: Local ischemic damage was detected by 2, 3, 5- triphenyltetra- zolium chloride staining, apoptosis in the penumbra was confirmed using the TUNEL method, and Bcl-2 protein expression in the penumbra was determined by indirect immunofluorescent staining and Western blot analysis. RESULTS: Compared with the normal saline and plasmid control groups, cerebral infarction size and the number of apoptotic cells in the pCDNA3.1(+)/Ngb group were significantly reduced (P < 0.01). The percentage of Bcl-2-positive cells in the penumbra of the pCDNA3.1(+)/Ngb group was significantly increased (P < 0.01). The relative expression level of Bcl-2 protein was increased by 40%-50%. CONCLUSION: Recombinant plasmid pCDNA3.1/Ngb provides neuroprotection by upregulating Bcl-2 expression and inhibiting cell apoptosis in the penumbra.展开更多
Glucose is the essential and almost exclusive metabolic fuel for the brain.Ischemic stroke caused by a blockage in one or more cerebral arteries quickly leads to a lack of regional cerebral blood supply resulting in s...Glucose is the essential and almost exclusive metabolic fuel for the brain.Ischemic stroke caused by a blockage in one or more cerebral arteries quickly leads to a lack of regional cerebral blood supply resulting in severe glucose deprivation with subsequent induction of cellular homeostasis disturbance and eventual neuronal death.To make up ischemiamediated adenosine 5′-triphosphate depletion,glucose in the ischemic penumbra area rapidly enters anaerobic metabolism to produce glycolytic adenosine 5′-triphosphate for cell survival.It appears that an increase in glucose in the ischemic brain would exert favorable effects.This notion is supported by in vitro studies,but generally denied by most in vivo studies.Clinical studies to manage increased blood glucose levels after stroke also failed to show any benefits or even brought out harmful effects while elevated admission blood glucose concentrations frequently correlated with poor outcomes.Surprisingly,strict glycaemic control in clinical practice also failed to yield any beneficial outcome.These controversial results from glucose management studies during the past three decades remain a challenging question of whether glucose intervention is needed for ischemic stroke care.This review provides a brief overview of the roles of cerebral glucose under normal and ischemic conditions and the results of managing glucose levels in non-diabetic patients.Moreover,the relationship between blood glucose and cerebral glucose during the ischemia/reperfusion processes and the potential benefits of low glucose supplements for non-diabetic patients are discussed.展开更多
Ischemic stroke is a common disease with high mortality and morbidity worldwide.One of the important pathophysiological effects of ischemic stroke is apoptosis.A neuroprotective effect is defined as the inhibition of ...Ischemic stroke is a common disease with high mortality and morbidity worldwide.One of the important pathophysiological effects of ischemic stroke is apoptosis.A neuroprotective effect is defined as the inhibition of neuronal apoptosis to rescue or delay the infarction in the surviving ischemic penumbra.Resveratrol is a natural polyphenol that reportedly prevents cerebral ischemia injury by regulating the expression of PI3K/AKT/mTOR.Therefore,this study aimed to elucidate the neuroprotective effect of resveratrol on cerebral ischemia/reperfusion injury and to investigate the signaling pathways and mechanisms through which resveratrol regulates apoptosis in the ischemic penumbra.Rats were subjected to middle cerebral artery occlusion for 2 h followed by 24 h reperfusion.Cerebral infarct volume was measured using 2%TTC staining.TUNEL staining was conducted to evaluate neuronal apoptosis.Western blotting and immunohistochemistry were used to detect the proteins involved in the JAK2/STAT3/PI3K/AKT/mTOR pathway.The results suggested that resveratrol significantly improved neurological function,reduced cerebral infarct volume,decreased neuronal damage,and markedly attenuated neuronal apoptosis;these effects were attenuated by the inhibition of PI3K/AKT with LY294002 and JAK2/STAT3 with AG490.We also found that resveratrol significantly upregulated the expression of p-JAK2,p-STAT3,p-AKT,p-mTOR,and BCL-2 and downregulated expression of cleaved caspase-3 and BAX,which was partially reversed by LY294002 and AG490.These results suggested that resveratrol provides a neuroprotective effect against cerebral ischemia/reperfusion injury,which is partially mediated by the activation of JAK2/STAT3 and PI3K/AKT/mTOR.Resveratrol may indirectly upregulate the PI3K/AKT/mTOR pathway by activating JAK2/STAT3.展开更多
基金National Natural Science Foundation of China(81603093)and the Open Research Fund of State Key Laboratory of Cellu⁃lar Stress Biology,Xiamen University(SKLC⁃SB2019KF016)。
文摘OBJECTIVE URB597(KDS-4103)is a potent and selective inhibitor of the enzyme fatty acid amide hydrolase(FAAH)and can ele⁃vate the level of oleoylethanolamide(OEA),a naturally occurring endocannabinoid in the brain.However,the effect of URB597 on cerebral isch⁃emic injury in mice remains unclear.METHODS Focal cerebral ischemia was induced by middle cerebral artery occlusion for 30 min followed by reperfusion for 24 h in mice.To observe the dose-dependent effect,URB597(0.04-5.00 mg·kg-1,ip)was administered at the same time of reperfu⁃sion.To determine the time-dependent effect,URB597(1.00 mg·kg-1,ip)was administered as a single dose at 0,1,3 or 5 h after reperfusion.Twenty-four hours after brain ischemia,Beder⁃son scoring test and grip strength test were used to evaluate the neurological function;brain in⁃farct volume was assayed by 2,3,5-triphenyltetra⁃zolium chloride(TTC)staining or diffusion-weighted magnetic resonance imaging(MRI).Laser speckle imaging(LSI)technique was used to assay the regional cerebral blood flow(rCBF);NeuN immunofluorescence staining was used to observe the neuron survival in the penumbra.To further investigate the underlying mechanism,au⁃tophagy flux related proteins(LC3-Ⅱ,P62 and LAMP2)and necroptosis related proteins(pRIPK3 and pMLKL)were detected by Western blotting and immunofluorescence staining.RESULTS Twenty-four hours after brain ischemia,URB597 dose-dependently improved neurological func⁃tion and reduced brain infarct volume.The most effective dose was 1.00 mg·kg-1;the therapeutic time window was within 1 h after ischemic stroke.The protective effect is further confirmed by the results that post-ischemic treatment with URB597(1.00 mg·kg-1)significantly increased neurons survival,promoted autophagy flux and reduced cell necroptosis in cortical penumbra after cerebral I/R.CONCLUSION URB597 dose-and time-dependently exerts a neuroprotective effect against acute cerebral I/R injury.This neu⁃roprotective effect of URB597 may be associated with its restoration of autophagy flux and inhibi⁃tion of neuronal necroptosis in the cortical penumbra.
基金a Grant from Chongqing Health Bureau, No. 06-2-177
文摘BACKGROUND: Adenovirus has been used to develop neuroglobin (Ngb) vectors. Although transfection efficiency is high, induced gene mutation, cytotoxicity, inflammation, and low exoge- nous gene content have limited its application. OBJECTIVE: To observe the effects of recombinant Ngb plasmid in a rat model of focal cerebral ischemia. DESIGN, TIME AND SETTING: Genetically engineered, randomized, controlled, animal experiment was performed at the Laboratory of Chongqing Medical University from May 2006 and January 2007. MATERIALS: 2, 3, 5-triphenyltetrazolium chloride was purchased from Shanghai Sangon Biological Engineering Technology and Services. Rabbit anti-rat Bcl-2 polyclonal antibody, rabbit anti-rat β-actin monoclonal antibody, and FITC-labeled goat anti-rabbit IgG were purchased from Sigma, USA. TUNEL apoptosis kit was purchased from Roche, Germany. METHODS: A total of 54 male, adult, Wistar rats were randomly assigned to 3 groups (n = 18): normal saline, plasmid control, and recombinant Ngb (pCDNA3.1(+)/Ngb). Normal saline, plasmid pCDNA3.1(+), and recombinant plasmid pCDNA3.1(+)/Ngb were separately injected into two sites in the rat cerebral cortex, and models of focal ischemia were established by occlusion of the right middle cerebral artery after 24 hours. MAIN OUTCOME MEASURES: Local ischemic damage was detected by 2, 3, 5- triphenyltetra- zolium chloride staining, apoptosis in the penumbra was confirmed using the TUNEL method, and Bcl-2 protein expression in the penumbra was determined by indirect immunofluorescent staining and Western blot analysis. RESULTS: Compared with the normal saline and plasmid control groups, cerebral infarction size and the number of apoptotic cells in the pCDNA3.1(+)/Ngb group were significantly reduced (P < 0.01). The percentage of Bcl-2-positive cells in the penumbra of the pCDNA3.1(+)/Ngb group was significantly increased (P < 0.01). The relative expression level of Bcl-2 protein was increased by 40%-50%. CONCLUSION: Recombinant plasmid pCDNA3.1/Ngb provides neuroprotection by upregulating Bcl-2 expression and inhibiting cell apoptosis in the penumbra.
基金supported by a grant from the National Institute of General Medical Sciences(SC1GM111178)to JX。
文摘Glucose is the essential and almost exclusive metabolic fuel for the brain.Ischemic stroke caused by a blockage in one or more cerebral arteries quickly leads to a lack of regional cerebral blood supply resulting in severe glucose deprivation with subsequent induction of cellular homeostasis disturbance and eventual neuronal death.To make up ischemiamediated adenosine 5′-triphosphate depletion,glucose in the ischemic penumbra area rapidly enters anaerobic metabolism to produce glycolytic adenosine 5′-triphosphate for cell survival.It appears that an increase in glucose in the ischemic brain would exert favorable effects.This notion is supported by in vitro studies,but generally denied by most in vivo studies.Clinical studies to manage increased blood glucose levels after stroke also failed to show any benefits or even brought out harmful effects while elevated admission blood glucose concentrations frequently correlated with poor outcomes.Surprisingly,strict glycaemic control in clinical practice also failed to yield any beneficial outcome.These controversial results from glucose management studies during the past three decades remain a challenging question of whether glucose intervention is needed for ischemic stroke care.This review provides a brief overview of the roles of cerebral glucose under normal and ischemic conditions and the results of managing glucose levels in non-diabetic patients.Moreover,the relationship between blood glucose and cerebral glucose during the ischemia/reperfusion processes and the potential benefits of low glucose supplements for non-diabetic patients are discussed.
基金supported by the Foundation for Science and Technology Research Project of Chongqing(cstc2012ggB1002).
文摘Ischemic stroke is a common disease with high mortality and morbidity worldwide.One of the important pathophysiological effects of ischemic stroke is apoptosis.A neuroprotective effect is defined as the inhibition of neuronal apoptosis to rescue or delay the infarction in the surviving ischemic penumbra.Resveratrol is a natural polyphenol that reportedly prevents cerebral ischemia injury by regulating the expression of PI3K/AKT/mTOR.Therefore,this study aimed to elucidate the neuroprotective effect of resveratrol on cerebral ischemia/reperfusion injury and to investigate the signaling pathways and mechanisms through which resveratrol regulates apoptosis in the ischemic penumbra.Rats were subjected to middle cerebral artery occlusion for 2 h followed by 24 h reperfusion.Cerebral infarct volume was measured using 2%TTC staining.TUNEL staining was conducted to evaluate neuronal apoptosis.Western blotting and immunohistochemistry were used to detect the proteins involved in the JAK2/STAT3/PI3K/AKT/mTOR pathway.The results suggested that resveratrol significantly improved neurological function,reduced cerebral infarct volume,decreased neuronal damage,and markedly attenuated neuronal apoptosis;these effects were attenuated by the inhibition of PI3K/AKT with LY294002 and JAK2/STAT3 with AG490.We also found that resveratrol significantly upregulated the expression of p-JAK2,p-STAT3,p-AKT,p-mTOR,and BCL-2 and downregulated expression of cleaved caspase-3 and BAX,which was partially reversed by LY294002 and AG490.These results suggested that resveratrol provides a neuroprotective effect against cerebral ischemia/reperfusion injury,which is partially mediated by the activation of JAK2/STAT3 and PI3K/AKT/mTOR.Resveratrol may indirectly upregulate the PI3K/AKT/mTOR pathway by activating JAK2/STAT3.
