Ischemic brain injury causes neuronal death and inflammation.Inflammation activates protein-tyrosine phosphatase 1B(PTP1B).Here,we tested the significance of PTP1B activation in glutamatergic projection neurons on fun...Ischemic brain injury causes neuronal death and inflammation.Inflammation activates protein-tyrosine phosphatase 1B(PTP1B).Here,we tested the significance of PTP1B activation in glutamatergic projection neurons on functional recovery in two models of stroke:by photothrombosis,focal ischemic lesions were induced in the sensorimotor cortex(SM stroke)or in the peri-prefrontal cortex(peri-PFC stroke).Elevated PTP1B expression was detected at 4 days and up to 6 weeks after stroke.While ablation of PTP1B in neurons of neuronal knockout(NKO)mice had no effect on the volume or resorption of ischemic lesions,markedly different effects on functional recovery were observed.SM stroke caused severe sensory and motor deficits(adhesive removal test)in wild type and NKO mice at 4 days,but NKO mice showed drastically improved sensory and motor functional recovery at 8 days.In addition,peri-PFC stroke caused anxiety-like behaviors(elevated plus maze and open field tests),and depression-like behaviors(forced swimming and tail suspension tests)in wild type mice 9 and 28 days after stroke,respectively,with minimal effect on sensory and motor function.Peri-PFC stroke-induced affective disorders were associated with fewer active(FosB+)neurons in the PFC and nucleus accumbens but more FosB+neurons in the basolateral amygdala,compared to sham-operated mice.In contrast,mice with neuronal ablation of PTP1B were protected from anxiety-like and depression-like behaviors and showed no change in FosB+neurons after peri-PFC stroke.Taken together,our study identifies neuronal PTP1B as a key component that hinders sensory and motor functional recovery and also contributes to the development of anxiety-like and depression-like behaviors after stroke.Thus,PTP1B may represent a novel therapeutic target to improve stroke recovery.All procedures for animal use were approved by the Animal Care and Use Committee of the University of Ottawa Animal Care and Veterinary Service(protocol 1806)on July 27,2018.展开更多
Glutamate is the main exc i tatory neurotransmitter in the brain and binds to two major classes of receptors,theα-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid(AMPA)and the N-methyl-D-aspartate(NMDA)receptors.U...Glutamate is the main exc i tatory neurotransmitter in the brain and binds to two major classes of receptors,theα-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid(AMPA)and the N-methyl-D-aspartate(NMDA)receptors.Unlike AMPA receptors that are immediately activated by glutamate release,NMDA receptors are blocked by magnesium and can only be activated by glutamate after membrane depolarization.Thus,NMDA receptors are only activated after repeated AMPA receptor activation by glutamate.NMDA receptors are,for the most part,calcium-permeable channels.Calcium influx through NMDA receptors modulates synaptic transmission in neurons based on prior history of excitation,and provides a means of scaling the strength of synapses required for Hebbian plasticity.展开更多
Patients with Alzheimer’s disease(AD)have progressive memory loss,inability to reason,and display anxiety that accelerates disease progressionJ.Evidence points to two deficits:1)the brain fails to respond to insulin ...Patients with Alzheimer’s disease(AD)have progressive memory loss,inability to reason,and display anxiety that accelerates disease progressionJ.Evidence points to two deficits:1)the brain fails to respond to insulin that regulates the formation of neuron connections required to store memories,and 2)deficits arise in the brain’s endogenous cannabinoid signaling that regulates mood and prevents anxiety(Aso and Ferrer,2014).In addition,leptin signaling,important in regulating hypothalamic synaptic plasticity and cognitive function is also affected in AD(McGregor and Harvey,2018).展开更多
基金This work was supported by grants from the Heart and Stroke Foundation of Canada(Nos.G-13-0002596&G-18-0022157,to HHCNo.G-16-00014085,to AFRS)+2 种基金the Natural Science and Engineering Research Council of Canada(No.RGPIN/06212-2014,to HHC,No.RGPIN/2016-04985,to AFRS)the Canadian Institutes of Health Research(No.201610PJT,to HHC)HHC is also supported by a Mid-Career Investigator Award(No.7506)from the Heart and Stroke Foundation of Ontario.How to cite this article:Cruz SA。
文摘Ischemic brain injury causes neuronal death and inflammation.Inflammation activates protein-tyrosine phosphatase 1B(PTP1B).Here,we tested the significance of PTP1B activation in glutamatergic projection neurons on functional recovery in two models of stroke:by photothrombosis,focal ischemic lesions were induced in the sensorimotor cortex(SM stroke)or in the peri-prefrontal cortex(peri-PFC stroke).Elevated PTP1B expression was detected at 4 days and up to 6 weeks after stroke.While ablation of PTP1B in neurons of neuronal knockout(NKO)mice had no effect on the volume or resorption of ischemic lesions,markedly different effects on functional recovery were observed.SM stroke caused severe sensory and motor deficits(adhesive removal test)in wild type and NKO mice at 4 days,but NKO mice showed drastically improved sensory and motor functional recovery at 8 days.In addition,peri-PFC stroke caused anxiety-like behaviors(elevated plus maze and open field tests),and depression-like behaviors(forced swimming and tail suspension tests)in wild type mice 9 and 28 days after stroke,respectively,with minimal effect on sensory and motor function.Peri-PFC stroke-induced affective disorders were associated with fewer active(FosB+)neurons in the PFC and nucleus accumbens but more FosB+neurons in the basolateral amygdala,compared to sham-operated mice.In contrast,mice with neuronal ablation of PTP1B were protected from anxiety-like and depression-like behaviors and showed no change in FosB+neurons after peri-PFC stroke.Taken together,our study identifies neuronal PTP1B as a key component that hinders sensory and motor functional recovery and also contributes to the development of anxiety-like and depression-like behaviors after stroke.Thus,PTP1B may represent a novel therapeutic target to improve stroke recovery.All procedures for animal use were approved by the Animal Care and Use Committee of the University of Ottawa Animal Care and Veterinary Service(protocol 1806)on July 27,2018.
基金supported by grants from the Heart and Stroke Foundation of Canada(G-13-0002596&G-18-0022157,to HHCG-16-00014085,to AFRS)+4 种基金Ontario Mental Health Foundation(to HHC),the Canadian Institutes of Health Research(201610PJT#376403,to HHC201610PJT#376503,to AFRS)the Natural Science and Engineering Research Council of Canada(RGPIN/06212-2014,to HHCRGPIN/2016-04985,to AFRS)supported by a Mid-Career Investigator Award(grant#7506)from the Heart and Stroke Foundation of Ontario.
文摘Glutamate is the main exc i tatory neurotransmitter in the brain and binds to two major classes of receptors,theα-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid(AMPA)and the N-methyl-D-aspartate(NMDA)receptors.Unlike AMPA receptors that are immediately activated by glutamate release,NMDA receptors are blocked by magnesium and can only be activated by glutamate after membrane depolarization.Thus,NMDA receptors are only activated after repeated AMPA receptor activation by glutamate.NMDA receptors are,for the most part,calcium-permeable channels.Calcium influx through NMDA receptors modulates synaptic transmission in neurons based on prior history of excitation,and provides a means of scaling the strength of synapses required for Hebbian plasticity.
基金supported by grants from the Heart and Stroke Foundation of Canada(to HHC,G-13-0002596&G-18-0022157to AFRS,G-16-00014085)+3 种基金the Natural Science and Engineering Research Council of Canada(to HHC,RGPIN/06212-2014to AFRS,RGPIN/2016-04985)the Canadian Institutes of Health Research(HHC,201610PJT)supported by a Mid-Career Investigator Award(grant No.7506)from the Heart and Stroke Foundation of Ontario。
文摘Patients with Alzheimer’s disease(AD)have progressive memory loss,inability to reason,and display anxiety that accelerates disease progressionJ.Evidence points to two deficits:1)the brain fails to respond to insulin that regulates the formation of neuron connections required to store memories,and 2)deficits arise in the brain’s endogenous cannabinoid signaling that regulates mood and prevents anxiety(Aso and Ferrer,2014).In addition,leptin signaling,important in regulating hypothalamic synaptic plasticity and cognitive function is also affected in AD(McGregor and Harvey,2018).
