Our previo us study demonstrated the potential therapeutic role of human neural stem cell-derived exosomes(hNSC-Exo)in ischemic stroke.Here,we loaded brain-derived neurotrophic factor(BDNF)into exosomes derived from N...Our previo us study demonstrated the potential therapeutic role of human neural stem cell-derived exosomes(hNSC-Exo)in ischemic stroke.Here,we loaded brain-derived neurotrophic factor(BDNF)into exosomes derived from NSCs to construct engineered exosomes(BDNF-hNSC-Exo)and compared their effects with those of hNSC-Exo on ischemic stroke both in vitro and in vivo.In a model of H_(2)O_(2)-induced oxidative stress in NSCs,BDNF-hNSC-Exo markedly enhanced cell survival.In a rat middle cerebral arte ry occlusion model,BDNF-hNSC-Exo not only inhibited the activation of microglia,but also promoted the differentiation of endogenous NSCs into neurons.These results suggest that BDNF can improve the function of NSC-derived exosomes in the treatment of ischemic stro ke.Our research may support the clinical use of other neurotrophic factors for central nervous system diseases.展开更多
Brain-derived neurotrophic factor(BDNF) regulates many neurological functions and plays a vital role during the recovery from central nervous system injuries. However, the changes in BDNF expression and associated fac...Brain-derived neurotrophic factor(BDNF) regulates many neurological functions and plays a vital role during the recovery from central nervous system injuries. However, the changes in BDNF expression and associated factors following hypoxia-ischemia induced neonatal brain damage, and the significance of these changes are not fully understood. In the present study, a rat model of hypoxic-ischemic brain damage was established through the occlusion of the right common carotid artery, followed by 2 hours in a hypoxic-ischemic environment. Rats with hypoxic-ischemic brain damage presented deficits in both sensory and motor functions, and obvious pathological changes could be detected in brain tissues. The m RNA expression levels of BDNF and its processing enzymes and receptors(Furin, matrix metallopeptidase 9, tissuetype plasminogen activator, tyrosine Kinase receptor B, plasminogen activator inhibitor-1, and Sortilin) were upregulated in the ipsilateral hippocampus and cerebral cortex 6 hours after injury;however, the expression levels of these m RNAs were found to be downregulated in the contralateral hippocampus and cerebral cortex. These findings suggest that BDNF and its processing enzymes and receptors may play important roles in the pathogenesis and recovery from neonatal hypoxic-ischemic brain damage. This study was approved by the Animal Ethics Committee of the University of South Australia(approval No. U12-18) on July 30, 2018.展开更多
Cerebral ischemia activates an endogenous repair program that induces plastic changes in neurons. In this study, we investigated the effects of environmental enrichment on spatial learning and memory as well as on syn...Cerebral ischemia activates an endogenous repair program that induces plastic changes in neurons. In this study, we investigated the effects of environmental enrichment on spatial learning and memory as well as on synaptic remodeling in a mouse model of chronic cerebral ischemia, produced by subjecting adult male C57 BL/6 mice to permanent left middle cerebral artery occlusion. Three days postoperatively, mice were randomly assigned to the environmental enrichment and standard housing groups. Mice in the standard housing group were housed and fed a standard diet. Mice in the environmental enrichment group were housed in a cage with various toys and fed a standard diet. Then, 28 days postoperatively, spatial learning and memory were tested using the Morris water maze. The expression levels of growth-associated protein 43, synaptophysin and postsynaptic density protein 95 in the hippocampus were analyzed by western blot assay. The number of synapses was evaluated by electron microscopy. In the water maze test, mice in the environmental enrichment group had a shorter escape latency, traveled markedly longer distances, spent more time in the correct quadrant(northeast zone), and had a higher frequency of crossings compared with the standard housing group. The expression levels of growth-associated protein 43, synaptophysin and postsynaptic density protein 95 were substantially upregulated in the hippocampus in the environmental enrichment group compared with the standard housing group. Furthermore, electron microscopy revealed that environmental enrichment increased the number of synapses in the hippocampal CA1 region. Collectively, these findings suggest that environmental enrichment ameliorates the spatial learning and memory impairment induced by permanent middle cerebral artery occlusion. Environmental enrichment in mice with cerebral ischemia likely promotes cognitive recovery by inducing plastic changes in synapses.展开更多
Stroke is a main cause of death and disability worldwide.The ability of the brain to selfrepair in the acute and chronic phases after stroke is minimal;however,promising stem cell-based interventions are emerging that...Stroke is a main cause of death and disability worldwide.The ability of the brain to selfrepair in the acute and chronic phases after stroke is minimal;however,promising stem cell-based interventions are emerging that may give substantial and possibly complete recovery of brain function after stroke.Many animal models and clinical trials have demonstrated that neural stem cells(NSCs)in the central nervous system can orchestrate neurological repair through nerve regeneration,neuron polarization,axon pruning,neurite outgrowth,repair of myelin,and remodeling of the microenvironment and brain networks.Compared with other types of stem cells,NSCs have unique advantages in cell replacement,paracrine action,inflammatory regulation and neuroprotection.Our review summarizes NSC origins,characteristics,therapeutic mechanisms and repair processes,then highlights current research findings and clinical evidence for NSC therapy.These results may be helpful to inform the direction of future stroke research and to guide clinical decision-making.展开更多
The mechanisms of age-associated memory impairment may be associated with glutamate receptor function and chromatin modification.To observe the effect of an enriched environment on the cognitive function of mice with ...The mechanisms of age-associated memory impairment may be associated with glutamate receptor function and chromatin modification.To observe the effect of an enriched environment on the cognitive function of mice with age-associated memory impairment,3-monthold C57BL/6 male mice("young"mice)were raised in a standard environment,while 24-month-old C57BL/6 male mice with memory impairment("age-associated memory impairment"mice)were raised in either a standard environment or an enriched environment.The enriched environment included a variety of stimuli involving movement and sensation.A water maze test was then used to measure cognitive function in the mice.Furthermore,quantitative real-time polymerase chain reaction and western blot assays were used to detect right hippocampal GluN2B mRNA as well as protein expression of GluN2B and CREB binding protein in all mice.In addition,chromatin immunoprecipitation was used to measure the extent of histone acetylation of the hippocampal GluN2B gene promoters.Compared with the young mice,the water maze performance of age-associated memory impairment mice in the standard environment was significantly decreased.In addition,there were significantly lower levels of total histone acetylation and expression of CREB binding protein in the hippocampus of age-associated memory impairment mice in the standard environment compared with the young mice.There were also significantly lower levels of histone acetylation,protein expression,and mRNA expression of GluN2B in the hippocampus of these mice.In contrast,in the age-associated memory impairment mice with the enriched environment intervention,the water maze performance and molecular biological indexes were significantly improved.These data confirm that an enriched environment can improve cognitive dysfunction in age-associated memory impairment mice,and suggest that the mechanisms may be related to the increased expression of CREB binding protein and the increased degree of total histone acetylation in the hippocampus of age-associated 展开更多
Emerging evidence indicates that pentraxin 3 is an acute-phase protein that is linked with the immune response to inflammation.It is also a newly discovered marker of anti-inflammatory A2 reactive astrocytes,and poten...Emerging evidence indicates that pentraxin 3 is an acute-phase protein that is linked with the immune response to inflammation.It is also a newly discovered marker of anti-inflammatory A2 reactive astrocytes,and potentially has multiple protective effects in stroke;however,its role in the adult brain after traumatic brain injury is unknown.In the present study,a moderate model of traumatic brain injury in mice was established using controlled cortical impact.The models were intraventricularly injected with recombinant pentraxin 3(the recombinant pentraxin 3 group)or an equal volume of vehicle(the control group).The sham-operated mice underwent craniotomy,but did not undergo the controlled cortical impact.The potential neuroprotective and neuroregenerative roles of pentraxin 3 were investigated on days 14 and 21 after traumatic brain injury.Western blot assay showed that the expression of endogenous pentraxin 3 was increased after traumatic brain injury in mice.Furthermore,the neurological severity test and wire grip test revealed that recombinant pentraxin 3 treatment reduced the neurological severity score and increased the wire grip score,suggesting an improved recovery of sensory-motor functions.The Morris water maze results demonstrated that recombinant pentraxin 3 treatment reduced the latency to the platform,increased the time spent in the correct quadrant,and increased the number of times traveled across the platform,thus suggesting an improved recovery of cognitive function.In addition,to investigate the effects of pentraxin 3 on astrocytes,specific markers of A2 astrocytes were detected in primary astrocyte cultures in vitro using western blot assay.The results demonstrated that pentraxin 3 administration activates A2 astrocytes.To explore the protective mechanisms of pentraxin 3,immunofluorescence staining was used.Intraventricular injection of recombinant pentraxin 3 increased neuronal maintenance in the peri-injured cortex and ipsilateral hippocampus,increased the number of doublecortin-positive neura展开更多
基金supported by the National Natural Science Foundation of China,No.81671819(to LKC)the Natural Science Foundation of Guangdong Province,Nos.2021A1515010001 and 2019A1515012103(both to LKC)。
文摘Our previo us study demonstrated the potential therapeutic role of human neural stem cell-derived exosomes(hNSC-Exo)in ischemic stroke.Here,we loaded brain-derived neurotrophic factor(BDNF)into exosomes derived from NSCs to construct engineered exosomes(BDNF-hNSC-Exo)and compared their effects with those of hNSC-Exo on ischemic stroke both in vitro and in vivo.In a model of H_(2)O_(2)-induced oxidative stress in NSCs,BDNF-hNSC-Exo markedly enhanced cell survival.In a rat middle cerebral arte ry occlusion model,BDNF-hNSC-Exo not only inhibited the activation of microglia,but also promoted the differentiation of endogenous NSCs into neurons.These results suggest that BDNF can improve the function of NSC-derived exosomes in the treatment of ischemic stro ke.Our research may support the clinical use of other neurotrophic factors for central nervous system diseases.
基金supported by the National Natural Science Foundation of China,No. 82001604 (to LLX)the Joint Subject of Southwest Medical University and Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University of China,No. 2018XYLH-004 (to LLX)+1 种基金the National Construction Project of Regional Chinese Medicine Treatment Centre of China,No. 2018205 (to XB)the National Construction Project of the Second Clinical Research Base of Chinese Medicine of China,No. 2018131 (to XB)。
文摘Brain-derived neurotrophic factor(BDNF) regulates many neurological functions and plays a vital role during the recovery from central nervous system injuries. However, the changes in BDNF expression and associated factors following hypoxia-ischemia induced neonatal brain damage, and the significance of these changes are not fully understood. In the present study, a rat model of hypoxic-ischemic brain damage was established through the occlusion of the right common carotid artery, followed by 2 hours in a hypoxic-ischemic environment. Rats with hypoxic-ischemic brain damage presented deficits in both sensory and motor functions, and obvious pathological changes could be detected in brain tissues. The m RNA expression levels of BDNF and its processing enzymes and receptors(Furin, matrix metallopeptidase 9, tissuetype plasminogen activator, tyrosine Kinase receptor B, plasminogen activator inhibitor-1, and Sortilin) were upregulated in the ipsilateral hippocampus and cerebral cortex 6 hours after injury;however, the expression levels of these m RNAs were found to be downregulated in the contralateral hippocampus and cerebral cortex. These findings suggest that BDNF and its processing enzymes and receptors may play important roles in the pathogenesis and recovery from neonatal hypoxic-ischemic brain damage. This study was approved by the Animal Ethics Committee of the University of South Australia(approval No. U12-18) on July 30, 2018.
基金supported by the National Natural Science Foundation of China,No.81672242(to YW)the Key Construction Projects of Shanghai Health and Family Planning on Weak Discipline,China,No.2015ZB0401(to YW)
文摘Cerebral ischemia activates an endogenous repair program that induces plastic changes in neurons. In this study, we investigated the effects of environmental enrichment on spatial learning and memory as well as on synaptic remodeling in a mouse model of chronic cerebral ischemia, produced by subjecting adult male C57 BL/6 mice to permanent left middle cerebral artery occlusion. Three days postoperatively, mice were randomly assigned to the environmental enrichment and standard housing groups. Mice in the standard housing group were housed and fed a standard diet. Mice in the environmental enrichment group were housed in a cage with various toys and fed a standard diet. Then, 28 days postoperatively, spatial learning and memory were tested using the Morris water maze. The expression levels of growth-associated protein 43, synaptophysin and postsynaptic density protein 95 in the hippocampus were analyzed by western blot assay. The number of synapses was evaluated by electron microscopy. In the water maze test, mice in the environmental enrichment group had a shorter escape latency, traveled markedly longer distances, spent more time in the correct quadrant(northeast zone), and had a higher frequency of crossings compared with the standard housing group. The expression levels of growth-associated protein 43, synaptophysin and postsynaptic density protein 95 were substantially upregulated in the hippocampus in the environmental enrichment group compared with the standard housing group. Furthermore, electron microscopy revealed that environmental enrichment increased the number of synapses in the hippocampal CA1 region. Collectively, these findings suggest that environmental enrichment ameliorates the spatial learning and memory impairment induced by permanent middle cerebral artery occlusion. Environmental enrichment in mice with cerebral ischemia likely promotes cognitive recovery by inducing plastic changes in synapses.
基金This work was supported by the National Natural Science Foundation of China,No.81471308(to JL)Program of China National Health Commission and National Medical Products Administration(NMPA),No.CMR-20161129-1003(to JL)+1 种基金Liaoning Province Excellent Talent Program Project,No.XLYC1902031(to JL)Dalian Innovation Fund,No.2018J11CY025(to JL).
文摘Stroke is a main cause of death and disability worldwide.The ability of the brain to selfrepair in the acute and chronic phases after stroke is minimal;however,promising stem cell-based interventions are emerging that may give substantial and possibly complete recovery of brain function after stroke.Many animal models and clinical trials have demonstrated that neural stem cells(NSCs)in the central nervous system can orchestrate neurological repair through nerve regeneration,neuron polarization,axon pruning,neurite outgrowth,repair of myelin,and remodeling of the microenvironment and brain networks.Compared with other types of stem cells,NSCs have unique advantages in cell replacement,paracrine action,inflammatory regulation and neuroprotection.Our review summarizes NSC origins,characteristics,therapeutic mechanisms and repair processes,then highlights current research findings and clinical evidence for NSC therapy.These results may be helpful to inform the direction of future stroke research and to guide clinical decision-making.
基金supported by the National Natural Science Foundation of China,Nos.81672242,81972141(both to YW)the China Postdoctoral Science Fund,No.2017M621675(to XW)+4 种基金the Natural Science Foundation of Jiangsu Province of China,No.BK20171280(to XW)the Six One Project of Scientific Research Project for High-Level Health Talents of Jiangsu Province of China,Nos.LGY2017028,LGY2018027(to XW)the Key Young Medical Talents Project of Jiangsu Province,No.QNRC2016339(to XW)the Yangzhou’s 13th Five-Year Plan for“Ke Jiao Qiang Wei”of China,No.ZDRC65(to XW)the Key Project of Shanghai Science and Technology on Biomedicine of China,No.17411953900(to YW)。
文摘The mechanisms of age-associated memory impairment may be associated with glutamate receptor function and chromatin modification.To observe the effect of an enriched environment on the cognitive function of mice with age-associated memory impairment,3-monthold C57BL/6 male mice("young"mice)were raised in a standard environment,while 24-month-old C57BL/6 male mice with memory impairment("age-associated memory impairment"mice)were raised in either a standard environment or an enriched environment.The enriched environment included a variety of stimuli involving movement and sensation.A water maze test was then used to measure cognitive function in the mice.Furthermore,quantitative real-time polymerase chain reaction and western blot assays were used to detect right hippocampal GluN2B mRNA as well as protein expression of GluN2B and CREB binding protein in all mice.In addition,chromatin immunoprecipitation was used to measure the extent of histone acetylation of the hippocampal GluN2B gene promoters.Compared with the young mice,the water maze performance of age-associated memory impairment mice in the standard environment was significantly decreased.In addition,there were significantly lower levels of total histone acetylation and expression of CREB binding protein in the hippocampus of age-associated memory impairment mice in the standard environment compared with the young mice.There were also significantly lower levels of histone acetylation,protein expression,and mRNA expression of GluN2B in the hippocampus of these mice.In contrast,in the age-associated memory impairment mice with the enriched environment intervention,the water maze performance and molecular biological indexes were significantly improved.These data confirm that an enriched environment can improve cognitive dysfunction in age-associated memory impairment mice,and suggest that the mechanisms may be related to the increased expression of CREB binding protein and the increased degree of total histone acetylation in the hippocampus of age-associated
基金supported by the National Natural Science Foundation of China,No.81571159(to XCS)the National Natural Science Foundation for Youth of China,Nos.81601072(to CJC),81801230(to JJZ),and 81901210(to YW)。
文摘Emerging evidence indicates that pentraxin 3 is an acute-phase protein that is linked with the immune response to inflammation.It is also a newly discovered marker of anti-inflammatory A2 reactive astrocytes,and potentially has multiple protective effects in stroke;however,its role in the adult brain after traumatic brain injury is unknown.In the present study,a moderate model of traumatic brain injury in mice was established using controlled cortical impact.The models were intraventricularly injected with recombinant pentraxin 3(the recombinant pentraxin 3 group)or an equal volume of vehicle(the control group).The sham-operated mice underwent craniotomy,but did not undergo the controlled cortical impact.The potential neuroprotective and neuroregenerative roles of pentraxin 3 were investigated on days 14 and 21 after traumatic brain injury.Western blot assay showed that the expression of endogenous pentraxin 3 was increased after traumatic brain injury in mice.Furthermore,the neurological severity test and wire grip test revealed that recombinant pentraxin 3 treatment reduced the neurological severity score and increased the wire grip score,suggesting an improved recovery of sensory-motor functions.The Morris water maze results demonstrated that recombinant pentraxin 3 treatment reduced the latency to the platform,increased the time spent in the correct quadrant,and increased the number of times traveled across the platform,thus suggesting an improved recovery of cognitive function.In addition,to investigate the effects of pentraxin 3 on astrocytes,specific markers of A2 astrocytes were detected in primary astrocyte cultures in vitro using western blot assay.The results demonstrated that pentraxin 3 administration activates A2 astrocytes.To explore the protective mechanisms of pentraxin 3,immunofluorescence staining was used.Intraventricular injection of recombinant pentraxin 3 increased neuronal maintenance in the peri-injured cortex and ipsilateral hippocampus,increased the number of doublecortin-positive neura
