The last two decades have witnessed a rapid decrease in mortality due to acute cerebral ischemia that paradoxically has led to a rapid increase in the number of patients that survive an acute ischemic stroke with vari...The last two decades have witnessed a rapid decrease in mortality due to acute cerebral ischemia that paradoxically has led to a rapid increase in the number of patients that survive an acute ischemic stroke with various degrees of disability.Unfortunately,the lack of an effective therapeutic strategy to promote neurological recovery among stroke survivors has led to a rapidly growing population of disabled patients.Thus,understanding the mechanisms of neurorepair in the ischemic brain is a priority with wide scientific,social and economic implications.Cerebral ischemia has a harmful effect on synaptic structure associated with the development of functional impairment.In agreement with these observations,experimental evidence indicates that synaptic repair underlies the recovery of neurological function following an ischemic stroke.Furthermore,it has become evident that synaptic plasticity is crucial not only during development and learning,but also for synaptic repair after an ischemic insult.The plasminogen activating system is assembled by a cascade of enzymes and their inhibitors initially thought to be solely involved in the generation of plasmin.However,recent work has shown that in the brain this system has an important function regulating the development of synaptic plasticity via mechanisms that not always require plasmin generation.Urokinase-type plasminogen activator(uPA)is a serine proteinase and one of the plasminogen activators,that upon binding to its receptor(uPAR)not only catalyzes the conversion of plasminogen into plasmin on the cell surface,but also activates cell signaling pathways that promote cell migration,proliferation and survival.The role of uPA is the brain is not fully understood.However,it has been reported while uPA and uPAR are abundantly found in the developing central nervous system,in the mature brain their expression is restricted to a limited group of cells.Remarkably,following an ischemic injury to the mature brain the expression of uPA and uPAR increases to levels comparable to those observed during development.More specifically,neurons release uPA during the recovery phase from an ischemic injury,and astrocytes,axonal boutons and dendritic spines recruit uPAR to their plasma membrane.Here we will review recent evidence indicating that binding of uPA to uPAR promotes the repair of synapses damaged by an ischemic injury,with the resultant recovery of neurological function.Furthermore,we will discuss data indicating that treatment with recombinant uPA is a potential therapeutic strategy to promote neurological recovery among ischemic stroke survivors.展开更多
Traumatic brain injury （TBI） and spinal cord injury （SCI） causes significant cell death （Raghupathi et al., 1995; DeKosky et al., 1998; Hall et al., 2005; Farkas and Povlishock, 2007） and tissue lesion in the ne...Traumatic brain injury （TBI） and spinal cord injury （SCI） causes significant cell death （Raghupathi et al., 1995; DeKosky et al., 1998; Hall et al., 2005; Farkas and Povlishock, 2007） and tissue lesion in the neocortex （Lighthall et al., 1989; Lyeth et al., 1990）, leaving many patients with substantial motor dis- ability and cognitive impairment （Harem et al., 1992; Scheff et al., 1997）. Unfortunately, at present, there are no clinically demonstrated FDA approved drug therapies for treatment of TBI and SCI patients that reduce the neurological injuries. Thus, TBI and SCI are serious health problems. The devel- opment of therapeutic approaches to prevent neuronal death and enhance neuroregeneration for promoting post-traumat- ic functional recovery would be of enormous clinical, social, and economic benefits. The reviews in this specific issue focus largely on the current progress on diagnosis, neuroprotection, and potential neurorepair with stem cells.展开更多
Mild traumatic brain injury（TBI）, also called concussion, initiates sequelae leading to motor deficits, cognitive impairments and subtly compromised neurobehaviors. While the acute phase of TBI is associated with ne...Mild traumatic brain injury（TBI）, also called concussion, initiates sequelae leading to motor deficits, cognitive impairments and subtly compromised neurobehaviors. While the acute phase of TBI is associated with neuroinflammation and nitroxidative burst, the chronic phase shows a lack of stimulation of the neurorepair process and regeneration. The deficiency of nitric oxide（NO）, the consequent disturbed NO metabolome, and imbalanced mechanisms of S-nitrosylation are implicated in blocking the mechanisms of neurorepair processes and functional recovery in the both phases. Hypoxia inducible factor-1 alpha（HIF-1α）, a master regulator of hypoxia/ischemia, stimulates the process of neurorepair and thus aids in functional recovery after brain trauma. The activity of HIF-1α is regulated by NO via the mechanism of S-nitrosylation of HIF-1α. S-nitrosylation is dynamically regulated by NO metabolites such as S-nitrosoglutathione（GSNO） and peroxynitrite. GSNO stabilizes, and peroxynitrite destabilizes HIF-1α. Exogenously administered GSNO was found not only to stabilize HIF-1α and to induce HIF-1α-dependent genes but also to stimulate the regeneration process and to aid in functional recovery in TBI animals.展开更多
Intracerebral hemorrhage （ICH） is the most severe cerebrovascular disease, which represents a leading cause of death and disability in developed countries. However, therapeutic options are limited, so is mandatory t...Intracerebral hemorrhage （ICH） is the most severe cerebrovascular disease, which represents a leading cause of death and disability in developed countries. However, therapeutic options are limited, so is mandatory to investigate repairing processes after stroke in order to develop new therapeutic strategies able to promote brain repair processes. Therapeutic angiogenesis and vasculogenesis hold promise to improve outcome of ICH patients. In this regard, circulating endothelial progenitor cells （EPCs） have recently been suggested to be a marker of vascular risk and endothelial function. Moreover, EPC levels have been associated with good neurological and functional outcome as well as reduced residual hematoma volume in ICH patients. Finally, experimental and clinical studies indicate that EPC might mediate endothelial cell regeneration and neovascularization. Therefore, EPC-based therapy could be an excellent therapeutic option in ICH. In this mini-review, we discuss the present status of knowledge about the possible therapeutic role of EPCs in ICH, molecular mechanisms, and the future perspectives and strategies for their use in clinical practice.展开更多
Biomaterials have increasingly become a focus of research on neuroprotection and neuroregeneration.Collagen,in terms of brain repair,presents many advantages such as being remarkably biocompatible,biodegradable,versat...Biomaterials have increasingly become a focus of research on neuroprotection and neuroregeneration.Collagen,in terms of brain repair,presents many advantages such as being remarkably biocompatible,biodegradable,versatile and non-toxic.Collagen can be used to form injectable scaffolds and micro/nano spheres in order to：（i） locally release therapeutic factors with the aim of protecting degenerating neurons in neurodegenerative conditions such as Alzheimer＇s or Parkinson＇s diseases,（ii） encapsulate stem cells for safe delivery,（iii） encapsulate genetically modified cells to provide a long term source of trophic factors,（iv） fill in the voids from injury to serve as a structural support and provide a permissive microenvironment to promote axonal growth.This mini-review summarizes different applications of collagen biomaterial for central nervous system protection and repair,as well as the future perspectives.Overall,collagen is a promising natural biomaterial with various applications which has the potential to progress the development of therapeutic strategies in central nervous system injuries and degeneration.展开更多
Spinal cord ischemia associated with trauma and surgical procedures including thoraco-abdominal aortic aneurysm repair and thoracic endovascular aortic repair results in devastating clinical deficits in patients. Beca...Spinal cord ischemia associated with trauma and surgical procedures including thoraco-abdominal aortic aneurysm repair and thoracic endovascular aortic repair results in devastating clinical deficits in patients. Because spinal cord ischemia is inadequately treated, we studied the effects of [4-((1 E)-2-(5-(4-hydroxy-3-methoxystyryl-)-1-phenyl-1 H-pyrazoyl-3-yl) vinyl)-2-methoxy-phenol)](CNB-001), a novel curcumin-based compound, in a rabbit SCI model. CNB-001 is known to inhibit human 5-lipoxygenase and 15-lipoxygenase and reduce the ischemia-induced inflammatory response. Moreover, CNB-001 can reduce the level of oxidative stress markers and potentiate brain-derived neurotrophic factor and brain-derived neurotrophic factor receptor signaling. The Tarlov scale and quantal analysis technique results revealed that CNB-001 administered as an intravenous dose(bolus) 30 minutes prior to spinal cord ischemia improved the behaviors of female New Zealand White rabbits. The improvements were similar to those produced by the uncompetitive N-methyl-D-aspartate receptor antagonist memantine. At 48 hours after aortic occlusion, there was a 42.7% increase(P < 0.05) in tolerated ischemia duration(n = 14) for rabbits treated with CNB-001(n = 16), and a 72.3% increase for rabbits treated with the positive control memantine(P < 0.05)(n = 23) compared to vehicle-treated ischemic rabbits(n = 22). CNB-001 is a potential important novel treatment for spinal cord ischemia induced by aortic occlusion. All experiments were approved by the CSMC Institutional Animal Care and Use Committee(IACUC #4311) on November 1,2012.展开更多
Activation of neuroprotective and particularly later neurorestorative mechanisms after stroke attempts to restore or compensate for lost functions.This potentially opens a wide window for restorative therapies to prom...Activation of neuroprotective and particularly later neurorestorative mechanisms after stroke attempts to restore or compensate for lost functions.This potentially opens a wide window for restorative therapies to promote brain repair and improve long-term functional recovery.Although extensively demonstrated in the preclinical setting,the efficacy of cell-based therapies in stroke patients has been modest at best,if any at all.Translational failure may be due to the ineffective survival and integration of transplanted cells in pro-death stroke microenvironments that are not conducive for the structural reconstruction of damaged brain tissue and repair-related network reorganization.Optimal systemic delivery,timing,cell product,and dose remain open as well.Fortunately,a better understanding of the brain plasticity mechanisms underlying stroke recovery has ushered in a combination approach of cell-based therapy and rehabilitation that is aimed at achieving additive,synergistic,or even maximal beneficial effects.This novel combination therapy is not only targeted at promoting exogenous and endogenous cell survival and augmenting stand-alone restorative mechanisms but also at utilizing rehabilitation to facilitate a graft–host structural and functional integration and plasticity that would effectively remodel stroke tissue and restitute lost functions.This review presents an overview of the combination of cell-based therapy and experimental rehabilitation in stroke models.It also discusses associated shortcomings as well as proposes strategies to address them and help facilitate the advancement of this combination approach.展开更多
基金supported in part by National Institutes of Health Grant NS-091201(to MY)VA MERIT Award IO1BX003441(to MY)
文摘The last two decades have witnessed a rapid decrease in mortality due to acute cerebral ischemia that paradoxically has led to a rapid increase in the number of patients that survive an acute ischemic stroke with various degrees of disability.Unfortunately,the lack of an effective therapeutic strategy to promote neurological recovery among stroke survivors has led to a rapidly growing population of disabled patients.Thus,understanding the mechanisms of neurorepair in the ischemic brain is a priority with wide scientific,social and economic implications.Cerebral ischemia has a harmful effect on synaptic structure associated with the development of functional impairment.In agreement with these observations,experimental evidence indicates that synaptic repair underlies the recovery of neurological function following an ischemic stroke.Furthermore,it has become evident that synaptic plasticity is crucial not only during development and learning,but also for synaptic repair after an ischemic insult.The plasminogen activating system is assembled by a cascade of enzymes and their inhibitors initially thought to be solely involved in the generation of plasmin.However,recent work has shown that in the brain this system has an important function regulating the development of synaptic plasticity via mechanisms that not always require plasmin generation.Urokinase-type plasminogen activator(uPA)is a serine proteinase and one of the plasminogen activators,that upon binding to its receptor(uPAR)not only catalyzes the conversion of plasminogen into plasmin on the cell surface,but also activates cell signaling pathways that promote cell migration,proliferation and survival.The role of uPA is the brain is not fully understood.However,it has been reported while uPA and uPAR are abundantly found in the developing central nervous system,in the mature brain their expression is restricted to a limited group of cells.Remarkably,following an ischemic injury to the mature brain the expression of uPA and uPAR increases to levels comparable to those observed during development.More specifically,neurons release uPA during the recovery phase from an ischemic injury,and astrocytes,axonal boutons and dendritic spines recruit uPAR to their plasma membrane.Here we will review recent evidence indicating that binding of uPA to uPAR promotes the repair of synapses damaged by an ischemic injury,with the resultant recovery of neurological function.Furthermore,we will discuss data indicating that treatment with recombinant uPA is a potential therapeutic strategy to promote neurological recovery among ischemic stroke survivors.
文摘Traumatic brain injury （TBI） and spinal cord injury （SCI） causes significant cell death （Raghupathi et al., 1995; DeKosky et al., 1998; Hall et al., 2005; Farkas and Povlishock, 2007） and tissue lesion in the neocortex （Lighthall et al., 1989; Lyeth et al., 1990）, leaving many patients with substantial motor dis- ability and cognitive impairment （Harem et al., 1992; Scheff et al., 1997）. Unfortunately, at present, there are no clinically demonstrated FDA approved drug therapies for treatment of TBI and SCI patients that reduce the neurological injuries. Thus, TBI and SCI are serious health problems. The devel- opment of therapeutic approaches to prevent neuronal death and enhance neuroregeneration for promoting post-traumat- ic functional recovery would be of enormous clinical, social, and economic benefits. The reviews in this specific issue focus largely on the current progress on diagnosis, neuroprotection, and potential neurorepair with stem cells.
基金supported by grants from VA merit awards(BX3401 and RX2090)
文摘Mild traumatic brain injury（TBI）, also called concussion, initiates sequelae leading to motor deficits, cognitive impairments and subtly compromised neurobehaviors. While the acute phase of TBI is associated with neuroinflammation and nitroxidative burst, the chronic phase shows a lack of stimulation of the neurorepair process and regeneration. The deficiency of nitric oxide（NO）, the consequent disturbed NO metabolome, and imbalanced mechanisms of S-nitrosylation are implicated in blocking the mechanisms of neurorepair processes and functional recovery in the both phases. Hypoxia inducible factor-1 alpha（HIF-1α）, a master regulator of hypoxia/ischemia, stimulates the process of neurorepair and thus aids in functional recovery after brain trauma. The activity of HIF-1α is regulated by NO via the mechanism of S-nitrosylation of HIF-1α. S-nitrosylation is dynamically regulated by NO metabolites such as S-nitrosoglutathione（GSNO） and peroxynitrite. GSNO stabilizes, and peroxynitrite destabilizes HIF-1α. Exogenously administered GSNO was found not only to stabilize HIF-1α and to induce HIF-1α-dependent genes but also to stimulate the regeneration process and to aid in functional recovery in TBI animals.
基金supported by grants from the Spanish Ministry of Economy and Competitiveness(SAF2014-56336)the Instituto de Salud Carlos III(PI13/00292&PI14/01879)+5 种基金the Spanish Research Network on Cerebrovascular Diseases(RETICS INVICTUSRD12/0014)the Xunta de Galicia(Department of Education,GRC2014/027)the European Union program FEDERF.Campos(CP14/00154)TS(CP12/03121)are recipients of a research contract from Miguel Servet Program of Instituto de Salud Carlos III
文摘Intracerebral hemorrhage （ICH） is the most severe cerebrovascular disease, which represents a leading cause of death and disability in developed countries. However, therapeutic options are limited, so is mandatory to investigate repairing processes after stroke in order to develop new therapeutic strategies able to promote brain repair processes. Therapeutic angiogenesis and vasculogenesis hold promise to improve outcome of ICH patients. In this regard, circulating endothelial progenitor cells （EPCs） have recently been suggested to be a marker of vascular risk and endothelial function. Moreover, EPC levels have been associated with good neurological and functional outcome as well as reduced residual hematoma volume in ICH patients. Finally, experimental and clinical studies indicate that EPC might mediate endothelial cell regeneration and neovascularization. Therefore, EPC-based therapy could be an excellent therapeutic option in ICH. In this mini-review, we discuss the present status of knowledge about the possible therapeutic role of EPCs in ICH, molecular mechanisms, and the future perspectives and strategies for their use in clinical practice.
基金supported by The Brain Mat Train project,which is funded by the European Union Horizon 2020 Programme(H2020-MSCA-ITN-2015)under the Marie Sklodowska-Curie Initial Training Network and Grant Agreement No.676408
文摘Biomaterials have increasingly become a focus of research on neuroprotection and neuroregeneration.Collagen,in terms of brain repair,presents many advantages such as being remarkably biocompatible,biodegradable,versatile and non-toxic.Collagen can be used to form injectable scaffolds and micro/nano spheres in order to：（i） locally release therapeutic factors with the aim of protecting degenerating neurons in neurodegenerative conditions such as Alzheimer＇s or Parkinson＇s diseases,（ii） encapsulate stem cells for safe delivery,（iii） encapsulate genetically modified cells to provide a long term source of trophic factors,（iv） fill in the voids from injury to serve as a structural support and provide a permissive microenvironment to promote axonal growth.This mini-review summarizes different applications of collagen biomaterial for central nervous system protection and repair,as well as the future perspectives.Overall,collagen is a promising natural biomaterial with various applications which has the potential to progress the development of therapeutic strategies in central nervous system injuries and degeneration.
文摘Spinal cord ischemia associated with trauma and surgical procedures including thoraco-abdominal aortic aneurysm repair and thoracic endovascular aortic repair results in devastating clinical deficits in patients. Because spinal cord ischemia is inadequately treated, we studied the effects of [4-((1 E)-2-(5-(4-hydroxy-3-methoxystyryl-)-1-phenyl-1 H-pyrazoyl-3-yl) vinyl)-2-methoxy-phenol)](CNB-001), a novel curcumin-based compound, in a rabbit SCI model. CNB-001 is known to inhibit human 5-lipoxygenase and 15-lipoxygenase and reduce the ischemia-induced inflammatory response. Moreover, CNB-001 can reduce the level of oxidative stress markers and potentiate brain-derived neurotrophic factor and brain-derived neurotrophic factor receptor signaling. The Tarlov scale and quantal analysis technique results revealed that CNB-001 administered as an intravenous dose(bolus) 30 minutes prior to spinal cord ischemia improved the behaviors of female New Zealand White rabbits. The improvements were similar to those produced by the uncompetitive N-methyl-D-aspartate receptor antagonist memantine. At 48 hours after aortic occlusion, there was a 42.7% increase(P < 0.05) in tolerated ischemia duration(n = 14) for rabbits treated with CNB-001(n = 16), and a 72.3% increase for rabbits treated with the positive control memantine(P < 0.05)(n = 23) compared to vehicle-treated ischemic rabbits(n = 22). CNB-001 is a potential important novel treatment for spinal cord ischemia induced by aortic occlusion. All experiments were approved by the CSMC Institutional Animal Care and Use Committee(IACUC #4311) on November 1,2012.
基金European Commission under the Horizon 2020 program,Grant/Award Number:681044。
文摘Activation of neuroprotective and particularly later neurorestorative mechanisms after stroke attempts to restore or compensate for lost functions.This potentially opens a wide window for restorative therapies to promote brain repair and improve long-term functional recovery.Although extensively demonstrated in the preclinical setting,the efficacy of cell-based therapies in stroke patients has been modest at best,if any at all.Translational failure may be due to the ineffective survival and integration of transplanted cells in pro-death stroke microenvironments that are not conducive for the structural reconstruction of damaged brain tissue and repair-related network reorganization.Optimal systemic delivery,timing,cell product,and dose remain open as well.Fortunately,a better understanding of the brain plasticity mechanisms underlying stroke recovery has ushered in a combination approach of cell-based therapy and rehabilitation that is aimed at achieving additive,synergistic,or even maximal beneficial effects.This novel combination therapy is not only targeted at promoting exogenous and endogenous cell survival and augmenting stand-alone restorative mechanisms but also at utilizing rehabilitation to facilitate a graft–host structural and functional integration and plasticity that would effectively remodel stroke tissue and restitute lost functions.This review presents an overview of the combination of cell-based therapy and experimental rehabilitation in stroke models.It also discusses associated shortcomings as well as proposes strategies to address them and help facilitate the advancement of this combination approach.
