Synapses are specialized structures that mediate information flow between neurons and target cells,and thus are the basis for neuronal system to execute various functions,including learning and memory.There are around...Synapses are specialized structures that mediate information flow between neurons and target cells,and thus are the basis for neuronal system to execute various functions,including learning and memory.There are around 1011 neurons in the human brain,with each neuron receiving thousands of synaptic inputs,either excitatory or inhibitory.A synapse is an asymmetric structure that is composed of pre-synaptic axon terminals,synaptic cleft,and postsynaptic compartments.Synapse formation involves a number of cell adhesion molecules,extracellular factors,and intracellular signaling or structural proteins.After the establishment of synaptic connections,synapses undergo structural or functional changes,known as synaptic plasticity which is believed to be regulated by neuronal activity and a variety of secreted factors.This review summarizes recent progress in the field of synapse development,with particular emphasis on the work carried out in China during the past 10 years(1999-2009).展开更多
N6-methyladenosine (m6A),catalyzed by the methyltransferase complex consisting of Mettl3 and Mettl14,is the most abundant RNA modification in mRNAs and participates in diverse biological processes. However,the roles a...N6-methyladenosine (m6A),catalyzed by the methyltransferase complex consisting of Mettl3 and Mettl14,is the most abundant RNA modification in mRNAs and participates in diverse biological processes. However,the roles and precise mechanisms of m6A modification in regulating neuronal development and adult neurogenesis remain unclear. Here,we examined the function of Mettl3,the key component of the complex,in neuronal development and adult neurogenesis of mice. We found that the depletion of Mettl3 significantly reduced m6A levels in adult neural stem cells (aNSCs) and inhibited the proliferation of aNSCs. Mettl3 depletion not only inhibited neu-ronal development and skewed the differentiation of aNSCs more toward glial lineage,but also affected the morphological maturation of newborn neurons in the adult brain. m6A immunoprecip-itation combined with deep sequencing (MeRIP-seq) revealed that m6A was predominantly enriched in transcripts related to neurogenesis and neuronal development. Mechanistically,m6A was present on the transcripts of histone methyltransferase Ezh2,and its reduction upon Mettl3 knockdown decreased both Ezh2 protein expression and consequent H3K27me3 levels. The defects of neurogenesis and neuronal development induced by Mettl3 depletion could be rescued by Ezh2 overexpression. Collectively,our results uncover a crosstalk between RNA and histone modifica-tions and indicate that Mettl3-mediated m6A modification plays an important role in regulating neurogenesis and neuronal development through modulating Ezh2.展开更多
MicroRNAs play important roles in post-transcriptional regulation of gene expression by inhibiting protein translation and/or promoting mRNA degradation.Importantly,biogenesis of microRNAs displays specific temporal a...MicroRNAs play important roles in post-transcriptional regulation of gene expression by inhibiting protein translation and/or promoting mRNA degradation.Importantly,biogenesis of microRNAs displays specific temporal and spatial profiles in distinct cell and tissue types and hence affects a broad spectrum of biological functions in normal cell growth and tumor development.Recent discoveries have revealed sophisticated mechanisms that control microRNA production and homeostasis in response to developmental and extracellular signals.Moreover,a link between dysregulation of microRNAs and human brain disorders has become increasingly evident.In this review,we focus on recent advances in understanding the regulation of microRNA biogenesis and function in neuronal and glial development in the mammalian brain,and dysregulation of the microRNA pathway in neurodevelopmental and neurodegenerative diseases.展开更多
The regulation of gene expression by microRNAs(miRNAs) is a recently discovered pattern of gene regulation in animals and plants.MiRNAs have been implicated in various aspects of animal development and cell differenti...The regulation of gene expression by microRNAs(miRNAs) is a recently discovered pattern of gene regulation in animals and plants.MiRNAs have been implicated in various aspects of animal development and cell differentiation,such as early embryonic development,neuronal development,muscle development,and lymphocyte development,by the analysis of genetic deletions of individual miRNAs in mammals.These studies show that miRNAs are key regulators in animal development and are potential causes of human diseases.Here we review some recent discoveries about the functions of miRNAs in cell differentiation and development.展开更多
Proper migration of neuronal somas and axonal growth cones to designated locations in the developing brain is essential for the assembly of functional neuronal circuits.Rapid progress in research of axon guidance and ...Proper migration of neuronal somas and axonal growth cones to designated locations in the developing brain is essential for the assembly of functional neuronal circuits.Rapid progress in research of axon guidance and neuronal migration has been made in the last twenty years.Chinese researchers began their exploration in this field ten years ago and have made significant contributions in clarifying the signal transduction of axon guidance and neuronal migration.Several unique experimental approaches,including the migration assay of single isolated neurons in response to locally delivered guidance cues,have been developed by Chinese neuroscientists to investigate the molecular machinery underlying these guidance events.展开更多
Adult neural stem cells （NSCs） reside in a restricted microenvironment, where their development is controlled by subtle and presently underexplored cues. This raises a significant question： what instructions must b...Adult neural stem cells （NSCs） reside in a restricted microenvironment, where their development is controlled by subtle and presently underexplored cues. This raises a significant question： what instructions must be provided by this supporting niche to regulate NSC development and functions？ Signaling from the niche is proposed to control many aspects of NSC behavior, including balancing the quiescence and proliferation of NSCs, determining the cell division mode （symmetric versus asymmetric）, and preventing premature depletion of stem cells to maintain neurogenesis throughout life. Interactions between neurogenic niches and NSCs also govern the homeostatic regulation of adult neurogenesis under diverse physiological, environmental, and pathological conditions. An important implication from revisiting many previously-identified regulatory factors is that most of them （e.g., the antidepressant fluoxetine and exercise） affect gross neurogenesis by acting downstream of NSCs at the level of intermediate progenitors and neuroblasts, while leaving the NSC pool unaffected. Therefore, it is critically important to address how various niche components, signaling pathways, and environmental stimuli differentially regulate distinct stages of adult neurogenesis.展开更多
Extracellular matrix(ECM)influences cell differentiation through its structural and biochemical properties.In nervous system,neuronal behavior is influenced by these ECMs structures which are present in a meshwork,fib...Extracellular matrix(ECM)influences cell differentiation through its structural and biochemical properties.In nervous system,neuronal behavior is influenced by these ECMs structures which are present in a meshwork,fibrous,or tubular forms encompassing specific molecular compositions.In addition to contact guidance,ECM composition and structures also exert its effect on neuronal differentiation.This short report reviewed the native ECM structure and composition in central nervous system and peripheral nervous system,and their impact on neural regeneration and neuronal differentiation.Using topographies,stem cells have been differentiated to neurons.Further,focussing on engineered biomimicking topographies,we highlighted the role of anisotropic topographies in stem cell differentiation to neurons and its recent temporal application for efficient neuronal differentiation.展开更多
Gila outnumber neurons and are the most abundant cell type in the nervous system. Whereas neurons are the major carriers, transducers, and processors of information, glial cells, once considered mainly to play a passi...Gila outnumber neurons and are the most abundant cell type in the nervous system. Whereas neurons are the major carriers, transducers, and processors of information, glial cells, once considered mainly to play a passive supporting role, are now recognized for their active contributions to almost every aspect of nervous system development. Recently, insights from the invertebrate organism Drosophila melanogaster have advanced our knowledge of glial cell biology. In particular, findings on neuron-glia interactions via intrinsic and extrinsic mechanisms have shed light on the importance of gtia during different stages of neuronal development. Here, we summarize recent advances in understanding the functions of Drosophila glia, which resemble their mammalian counterparts in morphology and function, neural stem-cell conversion, synapse formation, and developmental axon pruning. These discoveries reinforce the idea that glia are substantial players in the developing nervous system and further advance the understanding of mechanisms leading to neurodegeneration.展开更多
Retinal damage in the adult zebrafish induces Müller glia reprogramming to produce neuronal progenitor cells that proliferate and differentiate into retinal neurons.Notch signaling,which is a fundamental mechanis...Retinal damage in the adult zebrafish induces Müller glia reprogramming to produce neuronal progenitor cells that proliferate and differentiate into retinal neurons.Notch signaling,which is a fundamental mechanism known to drive cell-cell communication,is required to maintain Müller glia in a quiescent state in the undamaged retina,and repression of Notch signaling is necessary for Müller glia to reenter the cell cycle.The dynamic regulation of Notch signaling following retinal damage also directs proliferation and neurogenesis of the Müller glia-derived progenitor cells in a robust regeneration response.In contrast,mammalian Müller glia respond to retinal damage by entering a prolonged gliotic state that leads to additional neuronal death and permanent vision loss.Understanding the dynamic regulation of Notch signaling in the zebrafish retina may aid efforts to stimulate Müller glia reprogramming for regeneration of the diseased human retina.Recent findings identified DeltaB and Notch3 as the ligand-receptor pair that serves as the principal regulators of zebrafish Müller glia quiescence.In addition,multi-omics datasets and functional studies indicate that additional Notch receptors,ligands,and target genes regulate cell proliferation and neurogenesis during the regeneration time course.Still,our understanding of Notch signaling during retinal regeneration is limited.To fully appreciate the complex regulation of Notch signaling that is required for successful retinal regeneration,investigation of additional aspects of the pathway,such as post-translational modification of the receptors,ligand endocytosis,and interactions with other fundamental pathways is needed.Here we review various modes of Notch signaling regulation in the context of the vertebrate retina to put recent research in perspective and to identify open areas of inquiry.展开更多
Since Autism Spectrum Disorder (ASD) is strongly associated with chromosomal abnormalities of 16p11.2, and Autism has been linked to neuronal polarity defect, our study aimed to explore the role of 16p11.2 genes in re...Since Autism Spectrum Disorder (ASD) is strongly associated with chromosomal abnormalities of 16p11.2, and Autism has been linked to neuronal polarity defect, our study aimed to explore the role of 16p11.2 genes in regulating neuronal polarity. We performed a neuronal polarity assay in a high throughput manner for candidate genes at 16p11.2. Our most interesting finding was that three 16p11.2 candidate genes, DOC2a, Tbx-6 and KIF 22, affected neuronal polarity. Our research, for the first time, indicates a novel association between 16p11.2 and neuronal polarity. Our results support the hypothesis that 16p11.2 is required for neuronal polarity. Our research provides new important insights into molecular mechanisms underlying the tight association between 16p11.2 and several neural developmental disorders, including autism, epilepsy, mental retardation and schizophrenia.展开更多
文摘Synapses are specialized structures that mediate information flow between neurons and target cells,and thus are the basis for neuronal system to execute various functions,including learning and memory.There are around 1011 neurons in the human brain,with each neuron receiving thousands of synaptic inputs,either excitatory or inhibitory.A synapse is an asymmetric structure that is composed of pre-synaptic axon terminals,synaptic cleft,and postsynaptic compartments.Synapse formation involves a number of cell adhesion molecules,extracellular factors,and intracellular signaling or structural proteins.After the establishment of synaptic connections,synapses undergo structural or functional changes,known as synaptic plasticity which is believed to be regulated by neuronal activity and a variety of secreted factors.This review summarizes recent progress in the field of synapse development,with particular emphasis on the work carried out in China during the past 10 years(1999-2009).
基金supported in part by the International Collaboration Program of the Ministry of Science and Technology of China (Grant No. YS2017YFGH001214)the National Natural Science Foundation of China (Grant Nos. 31771395 and 31571518)+6 种基金the National Key R&D Program of China (Grant No. 2016YFC0900400)supported by the National Natural Science Foundation of China (Grant No. 31770872)the Youth Innovation Promotion Association (Grant No. CAS2018133)the National Key R&D Program of China, Stem Cell and Translational Research (Grant No. 2018YFA0109700)supported in part by the National Key R&D Program of China (Grant No. 2017YFC1001703)the Key R&D Program of Zhejiang Province (Grant No. 2017C03009)Zhejiang Provincial Program for the Cultivation of High-level Innovative Health Talents (2016-6), China
文摘N6-methyladenosine (m6A),catalyzed by the methyltransferase complex consisting of Mettl3 and Mettl14,is the most abundant RNA modification in mRNAs and participates in diverse biological processes. However,the roles and precise mechanisms of m6A modification in regulating neuronal development and adult neurogenesis remain unclear. Here,we examined the function of Mettl3,the key component of the complex,in neuronal development and adult neurogenesis of mice. We found that the depletion of Mettl3 significantly reduced m6A levels in adult neural stem cells (aNSCs) and inhibited the proliferation of aNSCs. Mettl3 depletion not only inhibited neu-ronal development and skewed the differentiation of aNSCs more toward glial lineage,but also affected the morphological maturation of newborn neurons in the adult brain. m6A immunoprecip-itation combined with deep sequencing (MeRIP-seq) revealed that m6A was predominantly enriched in transcripts related to neurogenesis and neuronal development. Mechanistically,m6A was present on the transcripts of histone methyltransferase Ezh2,and its reduction upon Mettl3 knockdown decreased both Ezh2 protein expression and consequent H3K27me3 levels. The defects of neurogenesis and neuronal development induced by Mettl3 depletion could be rescued by Ezh2 overexpression. Collectively,our results uncover a crosstalk between RNA and histone modifica-tions and indicate that Mettl3-mediated m6A modification plays an important role in regulating neurogenesis and neuronal development through modulating Ezh2.
文摘MicroRNAs play important roles in post-transcriptional regulation of gene expression by inhibiting protein translation and/or promoting mRNA degradation.Importantly,biogenesis of microRNAs displays specific temporal and spatial profiles in distinct cell and tissue types and hence affects a broad spectrum of biological functions in normal cell growth and tumor development.Recent discoveries have revealed sophisticated mechanisms that control microRNA production and homeostasis in response to developmental and extracellular signals.Moreover,a link between dysregulation of microRNAs and human brain disorders has become increasingly evident.In this review,we focus on recent advances in understanding the regulation of microRNA biogenesis and function in neuronal and glial development in the mammalian brain,and dysregulation of the microRNA pathway in neurodevelopmental and neurodegenerative diseases.
基金Supported by National Key Basic Research and Development Program of China (Grant No.2005CB724602)Knowledge Innovation Project of the Chinese Academy of Sciences (Grant Nos.KSCX2-YW-R-096,KSCX1-YW-R-64)
文摘The regulation of gene expression by microRNAs(miRNAs) is a recently discovered pattern of gene regulation in animals and plants.MiRNAs have been implicated in various aspects of animal development and cell differentiation,such as early embryonic development,neuronal development,muscle development,and lymphocyte development,by the analysis of genetic deletions of individual miRNAs in mammals.These studies show that miRNAs are key regulators in animal development and are potential causes of human diseases.Here we review some recent discoveries about the functions of miRNAs in cell differentiation and development.
基金supported by the Innovation Project of the Chinese Academy of Sciences (Grant No KSCX2-YW-R-103)National Natural Science Foundation of China (Grant No 30625023)the National Basic Research Program of China (Grant Nos 2006CB806600 and 2006CB943903)
文摘Proper migration of neuronal somas and axonal growth cones to designated locations in the developing brain is essential for the assembly of functional neuronal circuits.Rapid progress in research of axon guidance and neuronal migration has been made in the last twenty years.Chinese researchers began their exploration in this field ten years ago and have made significant contributions in clarifying the signal transduction of axon guidance and neuronal migration.Several unique experimental approaches,including the migration assay of single isolated neurons in response to locally delivered guidance cues,have been developed by Chinese neuroscientists to investigate the molecular machinery underlying these guidance events.
基金supported by startup funds from the Department of Pharmacology at the University of North Carolina (UNC)grants from NARSAD,the Whitehall Foundation+1 种基金the American Heart Association and a UNC Biological and Biomedical Sciences Program training grantan NIH T32 Neurobiology Curriculum training grant
文摘Adult neural stem cells （NSCs） reside in a restricted microenvironment, where their development is controlled by subtle and presently underexplored cues. This raises a significant question： what instructions must be provided by this supporting niche to regulate NSC development and functions？ Signaling from the niche is proposed to control many aspects of NSC behavior, including balancing the quiescence and proliferation of NSCs, determining the cell division mode （symmetric versus asymmetric）, and preventing premature depletion of stem cells to maintain neurogenesis throughout life. Interactions between neurogenic niches and NSCs also govern the homeostatic regulation of adult neurogenesis under diverse physiological, environmental, and pathological conditions. An important implication from revisiting many previously-identified regulatory factors is that most of them （e.g., the antidepressant fluoxetine and exercise） affect gross neurogenesis by acting downstream of NSCs at the level of intermediate progenitors and neuroblasts, while leaving the NSC pool unaffected. Therefore, it is critically important to address how various niche components, signaling pathways, and environmental stimuli differentially regulate distinct stages of adult neurogenesis.
基金supported by the Natural Sciences and Engineering Research Council of Canada(NSERC) Discovery(NSERC 2016040 to DJ,SM and EKFY)+4 种基金University of Waterloo start up fund(to DJ,SM and EKFY) for their generous fundingNSERC Undergraduate Student Research Awards(USRAto SM and EKFY)Collaborative Research and Training Experience(CREATE,401207296to SM and EKFY) for their generous partial funding
文摘Extracellular matrix(ECM)influences cell differentiation through its structural and biochemical properties.In nervous system,neuronal behavior is influenced by these ECMs structures which are present in a meshwork,fibrous,or tubular forms encompassing specific molecular compositions.In addition to contact guidance,ECM composition and structures also exert its effect on neuronal differentiation.This short report reviewed the native ECM structure and composition in central nervous system and peripheral nervous system,and their impact on neural regeneration and neuronal differentiation.Using topographies,stem cells have been differentiated to neurons.Further,focussing on engineered biomimicking topographies,we highlighted the role of anisotropic topographies in stem cell differentiation to neurons and its recent temporal application for efficient neuronal differentiation.
基金supported by grants from the National Basic Research Program of China (973 Program 2010CB944900 and 2013CB945602)the National Natural Science Foundation of China (31270825 and 31171043)Fundamental Research Funds for the Central Universities We thank members of the Ho lab for discussion and comments
文摘Gila outnumber neurons and are the most abundant cell type in the nervous system. Whereas neurons are the major carriers, transducers, and processors of information, glial cells, once considered mainly to play a passive supporting role, are now recognized for their active contributions to almost every aspect of nervous system development. Recently, insights from the invertebrate organism Drosophila melanogaster have advanced our knowledge of glial cell biology. In particular, findings on neuron-glia interactions via intrinsic and extrinsic mechanisms have shed light on the importance of gtia during different stages of neuronal development. Here, we summarize recent advances in understanding the functions of Drosophila glia, which resemble their mammalian counterparts in morphology and function, neural stem-cell conversion, synapse formation, and developmental axon pruning. These discoveries reinforce the idea that glia are substantial players in the developing nervous system and further advance the understanding of mechanisms leading to neurodegeneration.
基金National Eye Institute R01-EY024519 and U01-EY027267(to DRH)the Center for Zebrafish Research,University of Notre Dame.
文摘Retinal damage in the adult zebrafish induces Müller glia reprogramming to produce neuronal progenitor cells that proliferate and differentiate into retinal neurons.Notch signaling,which is a fundamental mechanism known to drive cell-cell communication,is required to maintain Müller glia in a quiescent state in the undamaged retina,and repression of Notch signaling is necessary for Müller glia to reenter the cell cycle.The dynamic regulation of Notch signaling following retinal damage also directs proliferation and neurogenesis of the Müller glia-derived progenitor cells in a robust regeneration response.In contrast,mammalian Müller glia respond to retinal damage by entering a prolonged gliotic state that leads to additional neuronal death and permanent vision loss.Understanding the dynamic regulation of Notch signaling in the zebrafish retina may aid efforts to stimulate Müller glia reprogramming for regeneration of the diseased human retina.Recent findings identified DeltaB and Notch3 as the ligand-receptor pair that serves as the principal regulators of zebrafish Müller glia quiescence.In addition,multi-omics datasets and functional studies indicate that additional Notch receptors,ligands,and target genes regulate cell proliferation and neurogenesis during the regeneration time course.Still,our understanding of Notch signaling during retinal regeneration is limited.To fully appreciate the complex regulation of Notch signaling that is required for successful retinal regeneration,investigation of additional aspects of the pathway,such as post-translational modification of the receptors,ligand endocytosis,and interactions with other fundamental pathways is needed.Here we review various modes of Notch signaling regulation in the context of the vertebrate retina to put recent research in perspective and to identify open areas of inquiry.
文摘Since Autism Spectrum Disorder (ASD) is strongly associated with chromosomal abnormalities of 16p11.2, and Autism has been linked to neuronal polarity defect, our study aimed to explore the role of 16p11.2 genes in regulating neuronal polarity. We performed a neuronal polarity assay in a high throughput manner for candidate genes at 16p11.2. Our most interesting finding was that three 16p11.2 candidate genes, DOC2a, Tbx-6 and KIF 22, affected neuronal polarity. Our research, for the first time, indicates a novel association between 16p11.2 and neuronal polarity. Our results support the hypothesis that 16p11.2 is required for neuronal polarity. Our research provides new important insights into molecular mechanisms underlying the tight association between 16p11.2 and several neural developmental disorders, including autism, epilepsy, mental retardation and schizophrenia.
