Recent evidence exists that glucose transporter 3（GLUT3） plays an important role in the energy metabolism in the brain.Most previous studies have been conducted using focal or hypoxic ischemia models and have focuse...Recent evidence exists that glucose transporter 3（GLUT3） plays an important role in the energy metabolism in the brain.Most previous studies have been conducted using focal or hypoxic ischemia models and have focused on changes in GLUT3 expression based on protein and m RNA levels rather than tissue levels.In the present study,we observed change in GLUT3 immunoreactivity in the adult gerbil hippocampus at various time points after 5 minutes of transient forebrain ischemia.In the sham-operated group,GLUT3 immunoreactivity in the hippocampal CA1 region was weak,in the pyramidal cells of the CA1 region increased in a time-dependent fashion 24 hours after ischemia,and in the hippocampal CA1 region decreased significantly between 2 and 5 days after ischemia,with high level of GLUT3 immunoreactivity observed in the CA1 region 10 days after ischemia.In a double immunofluorescence study using GLUT3 and glial-fibrillary acidic protein（GFAP）,we observed strong GLUT3 immunoreactivity in the astrocytes.GLUT3 immunoreactivity increased after ischemia and peaked 7 days in the dentate gyrus after ischemia/reperfusion.In a double immunofluorescence study using GLUT3 and doublecortin（DCX）,we observed low level of GLUT3 immunoreactivity in the differentiated neuroblasts of the subgranular zone of the dentate gyrus after ischemia.GLUT3 immunoreactivity in the sham-operated group was mainly detected in the subgranular zone of the dentate gyrus.These results suggest that the increase in GLUT3 immunoreactivity may be a compensatory mechanism to modulate glucose level in the hippocampal CA1 region and to promote adult neurogenesis in the dentate gyrus.展开更多
Parkinson’s disease is a neurodegenerative condition characterized by motor impairments caused by the selective loss of dopaminergic neurons in the substantia nigra.Levodopa is an effective and well-tolerated dopamin...Parkinson’s disease is a neurodegenerative condition characterized by motor impairments caused by the selective loss of dopaminergic neurons in the substantia nigra.Levodopa is an effective and well-tolerated dopamine replacement agent.However,levodopa provides only symptomatic improvements,without affecting the underlying pathology,and is associated with side effects after long-term use.Cell-based replacement is a promising strategy that offers the possibility to replace lost neurons in Parkinson’s disease treatment.Clinical studies of transplantation of human fetal ventral mesencephalic tissue have provided evidence that the grafted dopaminergic neurons can reinnervate the striatum,release dopamine,integrate into the host neural circuits,and improve motor functions.One of the limiting factors for cell therapy in Parkinson’s disease is the low survival rate of grafted dopaminergic cells.Different factors could cause cell death of dopaminergic neurons after grafting such as mechanical trauma,growth factor deprivation,hypoxia,and neuroinflammation.Neurotrophic factors play an essential role in the survival of grafted cells.However,direct,timely,and controllable delivery of neurotrophic factors into the brain faces important limitations.Different types of cells secrete neurotrophic factors constitutively and co-transplantation of these cells with dopaminergic neurons represents a feasible strategy to increase neuronal survival.In this review,we provide a general overview of the pioneering studies on cell transplantation developed in patients and animal models of Parkinson’s disease,with a focus on neurotrophic factor-secreting cells,with a particular interest in mesenchymal stromal cells;that co-implanted with dopaminergic neurons would serve as a strategy to increase cell survival and improve graft outcomes.展开更多
The brain is a dynamic organ of the biological renaissance due to the existence of neuroplasticity. Adult neurogenesis abides by every aspect of neuroplasticity in the intact brain and contributes to neural regenerati...The brain is a dynamic organ of the biological renaissance due to the existence of neuroplasticity. Adult neurogenesis abides by every aspect of neuroplasticity in the intact brain and contributes to neural regeneration in response to brain diseases and injury. The occurrence of adult neurogenesis has unequivocally been witnessed in human subjects, experimental and wildlife research including rodents, bats and cetaceans. Adult neurogenesis is a complex cellular process, in which generation of neuroblasts namely, neuroblastosis appears to be an integral process that occur in the limbic system and basal ganglia in addition to the canonical neurogenic niches. Neuroblastosis can be regulated by various factors and contributes to different functions of the brain. The characteristics and fate of neuroblasts have been found to be different among mammals regardless of their cognitive functions. Recently, regulation of neuroblastosis has been proposed for the sensorimotor interface and regenerative neuroplasticity of the adult brain. Hence, the understanding of adult neurogenesis at the functional level of neuroblasts requires a great scientific attention. Therefore, this mini-review provides a glimpse into the conceptual development of neuroplasticity, discusses the possible role of different types of neuroblasts and signifies neuroregenerative failure as a potential cause of dementia.展开更多
DNA damage can, but does not always, induce cell death. While several pathways linking DNA damage signals to mitochondria-dependent and -independent death machineries have been elucidated, the connectivity of these pa...DNA damage can, but does not always, induce cell death. While several pathways linking DNA damage signals to mitochondria-dependent and -independent death machineries have been elucidated, the connectivity of these pathways is subject to regulation by multiple other factors that are not well understood. We have proposed two conceptual models to explain the delayed and variable cell death response to DNA damage： integrative surveillance versus autonomous pathways. In this review, we discuss how these two models may explain the in vivo regulation of cell death induced by ionizing radiation （IR） in the developing central nervous system, where the death response is regulated by radiation dose, cell cycle status and neuronal development.展开更多
In the Drosophila larval brain, type I and type Ⅱ neuroblasts（NBs） undergo a series of asymmetric divisions which give rise to distinct progeny lineages. The intermediate neural progenitors（INPs） exist only in ty...In the Drosophila larval brain, type I and type Ⅱ neuroblasts（NBs） undergo a series of asymmetric divisions which give rise to distinct progeny lineages. The intermediate neural progenitors（INPs） exist only in type Ⅱ NB lineages. In this study, we reveal a novel function of Inscuteable（Insc） that acts to maintain type I NB lineage identity. In insc type I NB clones of mosaic analyses with a repressible cell marker（MARCM）, the formation of extra Deadpan（Dpn）tNB-like and GMC-like cells is observed. The lack of Insc leads to the defective localization and segregation of Numb during asymmetric cell division. By the end of cytokinesis, this results in insufficient Numb in ganglion mother cells（GMCs）. The formation of extra Deadpan（Dpn）tcells in insc clones is prevented by the attenuation of Notch activity. This suggests that Insc functions through the Numb/Notch signaling pathway. We also show that in the absence of Insc in type I NB lineages, the cellular identity of GMCs is altered where they adopt an INP-like cell fate as indicated by the initiation of Dpn expression accompanied by a transient presence of Earmuff（Erm）.These INP-like cells have the capacity to divide multiple times. We conclude that Insc is necessary for the maintenance of type I NB lineage identity. Genetic manipulations to eliminate most type I NBs with overproliferating type Ⅱ NBs in the larval brain lead to altered circadian rhythms and defective phototaxis in adult flies. This indicates that the homeogenesis of NB lineages is important for the adult＇s brain function.展开更多
Recovery following stroke involves neurogenesis and axonal remodeling within the ischemic brain. Gualou Guizhi decoction （GLGZD） is a Chinese traditional medicine used for the treatment of post-stroke limb spasm. GL...Recovery following stroke involves neurogenesis and axonal remodeling within the ischemic brain. Gualou Guizhi decoction （GLGZD） is a Chinese traditional medicine used for the treatment of post-stroke limb spasm. GLGZD has been reported to have neuroprotective effects in cerebral ischemic injury. However, the effects of GLGZD on neurogenesis and axonal remodeling following cerebral ischemia remain unknown. In this study, a rat model of focal cerebral ischemia/reperfusion was established by middle cerebral artery occlusion. Neurologi- cal function was assessed immediately after reperfusion using Longa＇s 5-point scoring system. The rats were randomly divided into vehicle and GLGZD groups. Rats in the sham group were given sham operation. The rats in the GLGZD group were intragastrically administered GLGZD, once daily, for 14 consecutive days. The rats in the vehicle and sham groups were intragastrically administered distilled water. Modified neurological severity score test, balance beam test and foot fault test were used to assess motor functional changes. Nissl staining was performed to evaluate histopathological changes in the brain. Immunofluorescence staining was used to examine cell proliferation using the marker 5-bromo-2＇-deoxyuridine （BrdU） as well as expression of the neural precursor marker doublecortin （DCX）, the astrocyte marker glial fibrillary acidic protein （GFAP） and the axon regeneration marker growth associated protein-43 （GAP-43）. GLGZD substan- tially mitigated pathological injury, increased the number of BrdU, DCX and GFAP-immunoreactive cells in the subventricular zone of the ischemic hemisphere, increased GAP-43 expression in the cortical peri-infarct region, and improved motor function. These findings suggest that GLGZD promotes neurological functional recovery by increasing cell proliferation, enhancing axonal regeneration, and in- creasing the numbers of neuronal precursors and astrocytes in the peri-infarct area.展开更多
Astrocytes, the major component of blood-brain barriers, have presented paradoxical profiles after cerebral ischemia and reperfusion in vivo and in vitro. Our previous study showed that sevoflurane preconditioning imp...Astrocytes, the major component of blood-brain barriers, have presented paradoxical profiles after cerebral ischemia and reperfusion in vivo and in vitro. Our previous study showed that sevoflurane preconditioning improved the integrity of blood-brain barriers after ischemia and reperfusion injury in rats. This led us to investigate the effects of sevoflurane preconditioning on the astrocytic dynamics in ischemia and reperfusion rats, in order to explore astrocytic cell-based mechanisms of sevoflurane preconditioning. In the present study, 2,3,5-triphenyltetrazolium chloride staining and Garcia behavioral scores were utilized to evaluate cerebral infarction and neurological outcome from day 1 to day 3 after transient middle cerebral artery occlusion surgery. Using immunofluorescent staining, we found that sevoflurane preconditioning substantially promoted the astrocytic activation and migration from the penumbra to the infarct with microglial activation from day 3 after middle cerebral artery occlusion. The formation of astrocytic scaffolds facilitated neuroblasts migrating from the subventricular zone to the lesion sites on day 14 after injury. Neural networks increased in the infarct of sevoflurane preconditioned rats, consistent with decreased infarct volume and improved neurological scores after ischemia and reperfusion injury. These findings demonstrate that sevoflurane preconditioning confers neuroprotection, not only by accelerating astrocytic spatial and temporal dynamics, but also providing astrocytic scaffolds for neuroblasts migration to ischemic regions, which facilitates neural reconstruction after brain ischemia.展开更多
Background： Glehnia littoralis has been used for traditional Asian medicine, which has diverse therapeutic activities. However, studies regarding neurogenic effects of G. littoralis have not yet been considered. Ther...Background： Glehnia littoralis has been used for traditional Asian medicine, which has diverse therapeutic activities. However, studies regarding neurogenic effects of G. littoralis have not yet been considered. Therefore, in this study, we examined effects of G. littoralis extract on cell proliferation, neuroblast differentiation, and the maturation of newborn neurons in the hippocampus of adult mice. Methods： A total of 39 male ICR mice （12 weeks old） were randomly assigned to vehicle-treated and 100 and 200 mg/kg G. littoralis extract-treated groups （n = 13 in each group）. Vehicle and G. littoralis extract were orally administrated for 28 days. To examine neurogenic effects ofG. litmralis extract, we performed immunohistochemistry tbr 5-bromo-2-deoxyuridine （BrdU, an indicator for cell proliferation） and doublecortin （DCX, an immature neuronal marker） and double immunofluorescence staining for BrdU and neuronal nuclear antigen （NeuN, a mature neuronal marker）. In addition, we examined expressional changes of brain-derived neurotrophic factor （BDNF） and its major receptor tropomyosin-related kinase B （TrkB） using Western blotting analysis. Results： Treatment with 200 mg/kg, not 100 mg/kg, significantly increased number of BrdU-immunoreactive （＋） and DCX＋ cells （48.0 ±3.1and 72.0 ± 3.8 cells/section, respectively） in the subgranular zone （SGZ） of the dentate gyrus （DG） and BrdU＊/NeuN＋ cells （17.0 ±1.5 cells/section） in the granule cell layer as well as in the SGZ. In addition, protein levels of BDNF and YrkB （about 232% and 244% of the vehicle-treated group, respectively） were significantly increased in the DG of the mice treated with 200 mg/kg ofG. littoralis extract. Conclusion： G. littoralis extract promots cell proliferation, neuroblast differentiation, and neuronal maturation in the hippocampal DG, and neurogenic effects might be closely related to increases ofBDN F and TrkB proteins by G. littoralis extract treatment.展开更多
New neurons are integrated into the circuitry of the olfactory bulb throughout the lifespan in the mamma- lian brain--including in humans. These new neurons are born in the subventricular zone and subsequently mature ...New neurons are integrated into the circuitry of the olfactory bulb throughout the lifespan in the mamma- lian brain--including in humans. These new neurons are born in the subventricular zone and subsequently mature as they are guided over long distances via the rostral migratory stream through mechanisms we are only just beginning to understand. Regeneration after brain injury is very limited, and although some neuroblasts from the rostral migratory stream will leave the path and migrate toward cortical lesion sites, this neuronal replacement is generally not sustained and therefore does not provide enough new neurons to alleviate functional deficits. Using newly discovered microtissue engineering techniques, we have built the first self-contained, implantable constructs that mimic the architecture and function of the rostral migratory stream. This engineered microtissue emulates the dense cord-like bundles of astrocytic somata and processes that are the hallmark anatomical feature of the glial tube. As such, our living microtissue-en- gineered rostral migratory stream can serve as an in vitro test bed for unlocking the secrets of neuroblast migration and maturation, and may potentially serve as a living transplantable construct derived from a patient＇s own cells that can redirect their own neuroblasts into lesion sites for sustained neuronal replace- ment following brain injury or neurodegenerative disease. In this paper, we summarize the development of fabrication methods for this microtissue-engineered rostral migratory stream and provide proof-of-princi- ple evidence that it promotes and directs migration of immature neurons.展开更多
Chromophore-assisted laser inactivation（CALI） is a technique that uses photochemically-generated reactive oxygen species to acutely inactivate target proteins in living cells.Neural development includes highly dynam...Chromophore-assisted laser inactivation（CALI） is a technique that uses photochemically-generated reactive oxygen species to acutely inactivate target proteins in living cells.Neural development includes highly dynamic cellular processes such as asymmetric cell division,migration,axon and dendrite outgrowth and synaptogenesis.Although many key molecules of neural development have been identified since the past decades,their spatiotemporal contributions to these cellular events are not well understood.CALI provides an appealing tool for elucidating the precise functions of these molecules during neural development.In this review,we summarize the principles of CALI,a recent microscopic setup to perform CALI experiments,and the application of CALI to the study of growth-cone motility and neuroblast asymmetric division.展开更多
Mutations in long-chain acyl-CoA synthetase 4 (ACSL4) are associated with non-syndromic X-linked intellectual disability (ID). However, the neural functions of ACSL4 and how loss of ACSL4 leads to ID remain largely un...Mutations in long-chain acyl-CoA synthetase 4 (ACSL4) are associated with non-syndromic X-linked intellectual disability (ID). However, the neural functions of ACSL4 and how loss of ACSL4 leads to ID remain largely unexplored. We report here that mutations in Acsl, the Drosophila ortholog of human ACSL3 and ACSL4, result in developmental defects of the mushroom body (MB), the center of olfactory learning and memory. Specifically, Acsl mutants show fewer MB neuroblasts (Nbs) due to reduced proliferation activity and premature differentiation. Consistently, these surviving Nbs show reduced expression of cyclin E, a key regulator of the G1-to S-phase cell cycle transition, and nuclear mislocalization of the transcriptional factor Prospero, which is known to repress self-renewal genes and activate differentiating genes. Furthermore, RNA-seq analysis reveals downregulated Nb-and cell-cyclerelated genes and upregulated neuronal differentiation genes in Acsl mutant Nbs. As Drosophila Acsl and human ACSL4 are functionally conserved, our findings provide novel insights into a critical and previously unappreciated role of Acsl in neurogenesis and the pathogenesis of ACSL4-related ID.展开更多
Oenanthe javanica is an aquatic perennial herb that belongs to theOenanthe genus in Apiaceae family, and it displays well-known medicinal properties such as protective effects against glu-tamate-induced neurotoxicity....Oenanthe javanica is an aquatic perennial herb that belongs to theOenanthe genus in Apiaceae family, and it displays well-known medicinal properties such as protective effects against glu-tamate-induced neurotoxicity. However, few studies regarding effects ofOenanthe javanica on neurogenesis in the brain have been reported. In this study, we examined the effects of a normal diet and a diet containing ethanol extract ofOenanthe javanica on cell proliferation and neu-roblast differentiation in the subgranular zone of the hippocampal dentate gyrus of adolescent rats using Ki-67 （an endogenous marker for cell proliferation） and doublecortin （a marker for neuroblast）. Our results showed thatOenanthe javanica extract signiifcantly increased the number of Ki-67-immunoreactive cells and doublecortin-immunoreactive neuroblasts in the subgranular zone of the dentate gyrus in the adolescent rats. In addition, the immunoreactivity of brain-derived neurotrophic factor was signiifcantly increased in the dentate gyrus of the Oenanthe javanica extract-treated group compared with the control group. However, we did not ifnd that vascular endothelial growth factor expression was increased in theOenanthe javanica extract-treated group compared with the control group. These results indicate thatOenanthe javanica extract improves cell proliferation and neuroblast differentiation by increasing brain-de-rived neurotrophic factor immunoreactivity in the rat dentate gyrus.展开更多
The binding properties of neural cell adhesion molecule are modulated by a polysialic acid moiety. This plays an important role in the migration of adult born neuroblasts from their area of origin, the subventricular ...The binding properties of neural cell adhesion molecule are modulated by a polysialic acid moiety. This plays an important role in the migration of adult born neuroblasts from their area of origin, the subventricular zone, towards the olfactory bulb. Polysialisation increases the migration speed of the cells and helps to prevent the neuroblasts from leaving their migration route, the rostral migratory stream. Here, we evaluated the potential of intraventricular application of endoneuraminidase-N, an enzyme that specifically cleaves polysialic acid from neural cell adhesion molecule, in a rat model for structural prefrontal cortex damage. As expected, endoneuraminidase-N caused the rostral migratory stream to become wider, with a less uniform cellular orientation. Furthermore, endoneuraminidase-N treatment caused the neuroblasts to leave the rostral migratory stream and migrate towards the lesioned tissue. Despite the neuroblasts not being differentiated into neurons after a survival time of three weeks, this technique provides a solid animal model for future work on the migration and differentiation of relocated neuroblasts and might provide a basis for a future endogenous stem cell-based therapy for structural brain damage. The experiments were approved by the local animal care committee(522-27-11/02-00, 115;Senatorin für Wissenschaft, Gesundheit und Verbraucherschutz, Bremen, Germany) on February 10, 2016.展开更多
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education,No.NRF-2013R1A1A2059364,NRF-2015R1D1A3A01020635)by 2013 Research Grant from Kangwon National Universitypartially supported by the Research Institute for Veterinary Science,Seoul National University
文摘Recent evidence exists that glucose transporter 3（GLUT3） plays an important role in the energy metabolism in the brain.Most previous studies have been conducted using focal or hypoxic ischemia models and have focused on changes in GLUT3 expression based on protein and m RNA levels rather than tissue levels.In the present study,we observed change in GLUT3 immunoreactivity in the adult gerbil hippocampus at various time points after 5 minutes of transient forebrain ischemia.In the sham-operated group,GLUT3 immunoreactivity in the hippocampal CA1 region was weak,in the pyramidal cells of the CA1 region increased in a time-dependent fashion 24 hours after ischemia,and in the hippocampal CA1 region decreased significantly between 2 and 5 days after ischemia,with high level of GLUT3 immunoreactivity observed in the CA1 region 10 days after ischemia.In a double immunofluorescence study using GLUT3 and glial-fibrillary acidic protein（GFAP）,we observed strong GLUT3 immunoreactivity in the astrocytes.GLUT3 immunoreactivity increased after ischemia and peaked 7 days in the dentate gyrus after ischemia/reperfusion.In a double immunofluorescence study using GLUT3 and doublecortin（DCX）,we observed low level of GLUT3 immunoreactivity in the differentiated neuroblasts of the subgranular zone of the dentate gyrus after ischemia.GLUT3 immunoreactivity in the sham-operated group was mainly detected in the subgranular zone of the dentate gyrus.These results suggest that the increase in GLUT3 immunoreactivity may be a compensatory mechanism to modulate glucose level in the hippocampal CA1 region and to promote adult neurogenesis in the dentate gyrus.
基金supported by grants from Consellería de Cultura,Educación e Ordenación Universitaria,Xunta de Galicia(ED431G/05,ED431C 2018/10)European Regional Development Fund(FEDER),Instituto de Salud CarlosⅢ(RD16/011/0016,RD21/0017/0031)Secretaría de Estado de Investigación,Desarrollo e Innovación(Grant/Award,number RTI2018-098830-B-I00)(to JLLG)。
文摘Parkinson’s disease is a neurodegenerative condition characterized by motor impairments caused by the selective loss of dopaminergic neurons in the substantia nigra.Levodopa is an effective and well-tolerated dopamine replacement agent.However,levodopa provides only symptomatic improvements,without affecting the underlying pathology,and is associated with side effects after long-term use.Cell-based replacement is a promising strategy that offers the possibility to replace lost neurons in Parkinson’s disease treatment.Clinical studies of transplantation of human fetal ventral mesencephalic tissue have provided evidence that the grafted dopaminergic neurons can reinnervate the striatum,release dopamine,integrate into the host neural circuits,and improve motor functions.One of the limiting factors for cell therapy in Parkinson’s disease is the low survival rate of grafted dopaminergic cells.Different factors could cause cell death of dopaminergic neurons after grafting such as mechanical trauma,growth factor deprivation,hypoxia,and neuroinflammation.Neurotrophic factors play an essential role in the survival of grafted cells.However,direct,timely,and controllable delivery of neurotrophic factors into the brain faces important limitations.Different types of cells secrete neurotrophic factors constitutively and co-transplantation of these cells with dopaminergic neurons represents a feasible strategy to increase neuronal survival.In this review,we provide a general overview of the pioneering studies on cell transplantation developed in patients and animal models of Parkinson’s disease,with a focus on neurotrophic factor-secreting cells,with a particular interest in mesenchymal stromal cells;that co-implanted with dopaminergic neurons would serve as a strategy to increase cell survival and improve graft outcomes.
基金supported by the FWF Special Research Program(SFB)F44(F4413-B23)"Cell Signaling in Chronic CNS Disorders",and through funding from the European Union’s Seventh Framework Program(FP7/2007-2013)under grant agreements n°HEALTH-F2-2011-278850(INMi ND),n°HEALTH-F2-2011-279288(IDEA),n°FP7-REGPOT-316120(Glow Brain)a startup grant from the Faculty Recharge Programme,University Grants Commission(UGC-FRP),New Delhi,India(to MK)+1 种基金a research grant from DST-SERB,New Delhi,India(EEQ/2016/000639)(to MK)an Early Career Research Award(ECR/2016/000741)(to MK)
文摘The brain is a dynamic organ of the biological renaissance due to the existence of neuroplasticity. Adult neurogenesis abides by every aspect of neuroplasticity in the intact brain and contributes to neural regeneration in response to brain diseases and injury. The occurrence of adult neurogenesis has unequivocally been witnessed in human subjects, experimental and wildlife research including rodents, bats and cetaceans. Adult neurogenesis is a complex cellular process, in which generation of neuroblasts namely, neuroblastosis appears to be an integral process that occur in the limbic system and basal ganglia in addition to the canonical neurogenic niches. Neuroblastosis can be regulated by various factors and contributes to different functions of the brain. The characteristics and fate of neuroblasts have been found to be different among mammals regardless of their cognitive functions. Recently, regulation of neuroblastosis has been proposed for the sensorimotor interface and regenerative neuroplasticity of the adult brain. Hence, the understanding of adult neurogenesis at the functional level of neuroblasts requires a great scientific attention. Therefore, this mini-review provides a glimpse into the conceptual development of neuroplasticity, discusses the possible role of different types of neuroblasts and signifies neuroregenerative failure as a potential cause of dementia.
文摘DNA damage can, but does not always, induce cell death. While several pathways linking DNA damage signals to mitochondria-dependent and -independent death machineries have been elucidated, the connectivity of these pathways is subject to regulation by multiple other factors that are not well understood. We have proposed two conceptual models to explain the delayed and variable cell death response to DNA damage： integrative surveillance versus autonomous pathways. In this review, we discuss how these two models may explain the in vivo regulation of cell death induced by ionizing radiation （IR） in the developing central nervous system, where the death response is regulated by radiation dose, cell cycle status and neuronal development.
基金supported by the National Basic Research Program of China (No.2013CB945600)the National Natural Science Foundation of China (No.31371381)
文摘In the Drosophila larval brain, type I and type Ⅱ neuroblasts（NBs） undergo a series of asymmetric divisions which give rise to distinct progeny lineages. The intermediate neural progenitors（INPs） exist only in type Ⅱ NB lineages. In this study, we reveal a novel function of Inscuteable（Insc） that acts to maintain type I NB lineage identity. In insc type I NB clones of mosaic analyses with a repressible cell marker（MARCM）, the formation of extra Deadpan（Dpn）tNB-like and GMC-like cells is observed. The lack of Insc leads to the defective localization and segregation of Numb during asymmetric cell division. By the end of cytokinesis, this results in insufficient Numb in ganglion mother cells（GMCs）. The formation of extra Deadpan（Dpn）tcells in insc clones is prevented by the attenuation of Notch activity. This suggests that Insc functions through the Numb/Notch signaling pathway. We also show that in the absence of Insc in type I NB lineages, the cellular identity of GMCs is altered where they adopt an INP-like cell fate as indicated by the initiation of Dpn expression accompanied by a transient presence of Earmuff（Erm）.These INP-like cells have the capacity to divide multiple times. We conclude that Insc is necessary for the maintenance of type I NB lineage identity. Genetic manipulations to eliminate most type I NBs with overproliferating type Ⅱ NBs in the larval brain lead to altered circadian rhythms and defective phototaxis in adult flies. This indicates that the homeogenesis of NB lineages is important for the adult＇s brain function.
基金supported by a grant from the Research Project of Fujian Provincial Health and Family Planning Commission of China,No.2014-ZQN-JC-32a grant from the Project of Fujian Province Office of Education of China,No.JZ160442+1 种基金the Natural Science Foundation of Fujian Province of China,No.2018J01855a grant from the Platform for Preclinical Studies of Traditional Chinese Medicine and Quality Control Engineering Technology Research Center of Fujian Province of China,No.2009Y2003
文摘Recovery following stroke involves neurogenesis and axonal remodeling within the ischemic brain. Gualou Guizhi decoction （GLGZD） is a Chinese traditional medicine used for the treatment of post-stroke limb spasm. GLGZD has been reported to have neuroprotective effects in cerebral ischemic injury. However, the effects of GLGZD on neurogenesis and axonal remodeling following cerebral ischemia remain unknown. In this study, a rat model of focal cerebral ischemia/reperfusion was established by middle cerebral artery occlusion. Neurologi- cal function was assessed immediately after reperfusion using Longa＇s 5-point scoring system. The rats were randomly divided into vehicle and GLGZD groups. Rats in the sham group were given sham operation. The rats in the GLGZD group were intragastrically administered GLGZD, once daily, for 14 consecutive days. The rats in the vehicle and sham groups were intragastrically administered distilled water. Modified neurological severity score test, balance beam test and foot fault test were used to assess motor functional changes. Nissl staining was performed to evaluate histopathological changes in the brain. Immunofluorescence staining was used to examine cell proliferation using the marker 5-bromo-2＇-deoxyuridine （BrdU） as well as expression of the neural precursor marker doublecortin （DCX）, the astrocyte marker glial fibrillary acidic protein （GFAP） and the axon regeneration marker growth associated protein-43 （GAP-43）. GLGZD substan- tially mitigated pathological injury, increased the number of BrdU, DCX and GFAP-immunoreactive cells in the subventricular zone of the ischemic hemisphere, increased GAP-43 expression in the cortical peri-infarct region, and improved motor function. These findings suggest that GLGZD promotes neurological functional recovery by increasing cell proliferation, enhancing axonal regeneration, and in- creasing the numbers of neuronal precursors and astrocytes in the peri-infarct area.
基金supported by the National Natural Science Foundation of China,No.81200937(to QY)
文摘Astrocytes, the major component of blood-brain barriers, have presented paradoxical profiles after cerebral ischemia and reperfusion in vivo and in vitro. Our previous study showed that sevoflurane preconditioning improved the integrity of blood-brain barriers after ischemia and reperfusion injury in rats. This led us to investigate the effects of sevoflurane preconditioning on the astrocytic dynamics in ischemia and reperfusion rats, in order to explore astrocytic cell-based mechanisms of sevoflurane preconditioning. In the present study, 2,3,5-triphenyltetrazolium chloride staining and Garcia behavioral scores were utilized to evaluate cerebral infarction and neurological outcome from day 1 to day 3 after transient middle cerebral artery occlusion surgery. Using immunofluorescent staining, we found that sevoflurane preconditioning substantially promoted the astrocytic activation and migration from the penumbra to the infarct with microglial activation from day 3 after middle cerebral artery occlusion. The formation of astrocytic scaffolds facilitated neuroblasts migrating from the subventricular zone to the lesion sites on day 14 after injury. Neural networks increased in the infarct of sevoflurane preconditioned rats, consistent with decreased infarct volume and improved neurological scores after ischemia and reperfusion injury. These findings demonstrate that sevoflurane preconditioning confers neuroprotection, not only by accelerating astrocytic spatial and temporal dynamics, but also providing astrocytic scaffolds for neuroblasts migration to ischemic regions, which facilitates neural reconstruction after brain ischemia.
文摘Background： Glehnia littoralis has been used for traditional Asian medicine, which has diverse therapeutic activities. However, studies regarding neurogenic effects of G. littoralis have not yet been considered. Therefore, in this study, we examined effects of G. littoralis extract on cell proliferation, neuroblast differentiation, and the maturation of newborn neurons in the hippocampus of adult mice. Methods： A total of 39 male ICR mice （12 weeks old） were randomly assigned to vehicle-treated and 100 and 200 mg/kg G. littoralis extract-treated groups （n = 13 in each group）. Vehicle and G. littoralis extract were orally administrated for 28 days. To examine neurogenic effects ofG. litmralis extract, we performed immunohistochemistry tbr 5-bromo-2-deoxyuridine （BrdU, an indicator for cell proliferation） and doublecortin （DCX, an immature neuronal marker） and double immunofluorescence staining for BrdU and neuronal nuclear antigen （NeuN, a mature neuronal marker）. In addition, we examined expressional changes of brain-derived neurotrophic factor （BDNF） and its major receptor tropomyosin-related kinase B （TrkB） using Western blotting analysis. Results： Treatment with 200 mg/kg, not 100 mg/kg, significantly increased number of BrdU-immunoreactive （＋） and DCX＋ cells （48.0 ±3.1and 72.0 ± 3.8 cells/section, respectively） in the subgranular zone （SGZ） of the dentate gyrus （DG） and BrdU＊/NeuN＋ cells （17.0 ±1.5 cells/section） in the granule cell layer as well as in the SGZ. In addition, protein levels of BDNF and YrkB （about 232% and 244% of the vehicle-treated group, respectively） were significantly increased in the DG of the mice treated with 200 mg/kg ofG. littoralis extract. Conclusion： G. littoralis extract promots cell proliferation, neuroblast differentiation, and neuronal maturation in the hippocampal DG, and neurogenic effects might be closely related to increases ofBDN F and TrkB proteins by G. littoralis extract treatment.
基金supported by the National Institutes of Health[U01-NS094340(Cullen),F31-NS090746(Katiyar)&F32-NS103253(O’Donnell)]University of Pennsylvania[Center for Undergraduate Research&Fellowships(Panzer)]+2 种基金Michael J.Fox Foundation[Therapeutic Pipeline Program#9998(Cullen)]Department of Veterans Affairs[RR&D Merit Review I01-RX001097(Cullen)&BLR&D Merit Review I01-BX003748(Cullen)]the U.S.Army Medical Research and Materiel Command[W81XWH-16-1-0796(Cullen)]
文摘New neurons are integrated into the circuitry of the olfactory bulb throughout the lifespan in the mamma- lian brain--including in humans. These new neurons are born in the subventricular zone and subsequently mature as they are guided over long distances via the rostral migratory stream through mechanisms we are only just beginning to understand. Regeneration after brain injury is very limited, and although some neuroblasts from the rostral migratory stream will leave the path and migrate toward cortical lesion sites, this neuronal replacement is generally not sustained and therefore does not provide enough new neurons to alleviate functional deficits. Using newly discovered microtissue engineering techniques, we have built the first self-contained, implantable constructs that mimic the architecture and function of the rostral migratory stream. This engineered microtissue emulates the dense cord-like bundles of astrocytic somata and processes that are the hallmark anatomical feature of the glial tube. As such, our living microtissue-en- gineered rostral migratory stream can serve as an in vitro test bed for unlocking the secrets of neuroblast migration and maturation, and may potentially serve as a living transplantable construct derived from a patient＇s own cells that can redirect their own neuroblasts into lesion sites for sustained neuronal replace- ment following brain injury or neurodegenerative disease. In this paper, we summarize the development of fabrication methods for this microtissue-engineered rostral migratory stream and provide proof-of-princi- ple evidence that it promotes and directs migration of immature neurons.
基金supported by grants from the National Basic Research Program of China (973 Program) to W.L.and G.O.(2012CB966800 and 2012CB945002)the National Natural Science Foundation of China to W.L.and G.O.(31101002,31171295 and 31190063)the Junior Thousand Talents Program of China to G.O
文摘Chromophore-assisted laser inactivation（CALI） is a technique that uses photochemically-generated reactive oxygen species to acutely inactivate target proteins in living cells.Neural development includes highly dynamic cellular processes such as asymmetric cell division,migration,axon and dendrite outgrowth and synaptogenesis.Although many key molecules of neural development have been identified since the past decades,their spatiotemporal contributions to these cellular events are not well understood.CALI provides an appealing tool for elucidating the precise functions of these molecules during neural development.In this review,we summarize the principles of CALI,a recent microscopic setup to perform CALI experiments,and the application of CALI to the study of growth-cone motility and neuroblast asymmetric division.
基金supported by the grants from the Ministry of Science and Technology (2016YFA0501000)the National Science Foundation of China to YQZ (31490592) and AY (31271121)
文摘Mutations in long-chain acyl-CoA synthetase 4 (ACSL4) are associated with non-syndromic X-linked intellectual disability (ID). However, the neural functions of ACSL4 and how loss of ACSL4 leads to ID remain largely unexplored. We report here that mutations in Acsl, the Drosophila ortholog of human ACSL3 and ACSL4, result in developmental defects of the mushroom body (MB), the center of olfactory learning and memory. Specifically, Acsl mutants show fewer MB neuroblasts (Nbs) due to reduced proliferation activity and premature differentiation. Consistently, these surviving Nbs show reduced expression of cyclin E, a key regulator of the G1-to S-phase cell cycle transition, and nuclear mislocalization of the transcriptional factor Prospero, which is known to repress self-renewal genes and activate differentiating genes. Furthermore, RNA-seq analysis reveals downregulated Nb-and cell-cyclerelated genes and upregulated neuronal differentiation genes in Acsl mutant Nbs. As Drosophila Acsl and human ACSL4 are functionally conserved, our findings provide novel insights into a critical and previously unappreciated role of Acsl in neurogenesis and the pathogenesis of ACSL4-related ID.
基金supported by Hallym University Specialization Fund,No.HRF-S-12
文摘Oenanthe javanica is an aquatic perennial herb that belongs to theOenanthe genus in Apiaceae family, and it displays well-known medicinal properties such as protective effects against glu-tamate-induced neurotoxicity. However, few studies regarding effects ofOenanthe javanica on neurogenesis in the brain have been reported. In this study, we examined the effects of a normal diet and a diet containing ethanol extract ofOenanthe javanica on cell proliferation and neu-roblast differentiation in the subgranular zone of the hippocampal dentate gyrus of adolescent rats using Ki-67 （an endogenous marker for cell proliferation） and doublecortin （a marker for neuroblast）. Our results showed thatOenanthe javanica extract signiifcantly increased the number of Ki-67-immunoreactive cells and doublecortin-immunoreactive neuroblasts in the subgranular zone of the dentate gyrus in the adolescent rats. In addition, the immunoreactivity of brain-derived neurotrophic factor was signiifcantly increased in the dentate gyrus of the Oenanthe javanica extract-treated group compared with the control group. However, we did not ifnd that vascular endothelial growth factor expression was increased in theOenanthe javanica extract-treated group compared with the control group. These results indicate thatOenanthe javanica extract improves cell proliferation and neuroblast differentiation by increasing brain-de-rived neurotrophic factor immunoreactivity in the rat dentate gyrus.
文摘The binding properties of neural cell adhesion molecule are modulated by a polysialic acid moiety. This plays an important role in the migration of adult born neuroblasts from their area of origin, the subventricular zone, towards the olfactory bulb. Polysialisation increases the migration speed of the cells and helps to prevent the neuroblasts from leaving their migration route, the rostral migratory stream. Here, we evaluated the potential of intraventricular application of endoneuraminidase-N, an enzyme that specifically cleaves polysialic acid from neural cell adhesion molecule, in a rat model for structural prefrontal cortex damage. As expected, endoneuraminidase-N caused the rostral migratory stream to become wider, with a less uniform cellular orientation. Furthermore, endoneuraminidase-N treatment caused the neuroblasts to leave the rostral migratory stream and migrate towards the lesioned tissue. Despite the neuroblasts not being differentiated into neurons after a survival time of three weeks, this technique provides a solid animal model for future work on the migration and differentiation of relocated neuroblasts and might provide a basis for a future endogenous stem cell-based therapy for structural brain damage. The experiments were approved by the local animal care committee(522-27-11/02-00, 115;Senatorin für Wissenschaft, Gesundheit und Verbraucherschutz, Bremen, Germany) on February 10, 2016.
