Spinal cord injury is a severe neurological condition with limited neuronal regeneration and functional recovery.Currently,no effective treatments exist to improve spinal cord injury prognosis.Neuronal guidance protei...Spinal cord injury is a severe neurological condition with limited neuronal regeneration and functional recovery.Currently,no effective treatments exist to improve spinal cord injury prognosis.Neuronal guidance proteins are a diverse group of molecules that play crucial roles in axon and dendrite growth during nervous system development.Increasing evidence highlights their regulatory functions in spinal cord injury.This review provides a brief overview of the modulation patterns of key neuronal guidance proteins in neuronal axon growth during nervous system formation and subsequently focuses on their roles in neuronal regeneration and functional recovery following spinal cord injury.Neuronal guidance proteins include,but are not limited to,semaphorins and their receptors,plexins;netrins and their receptors,deleted in colorectal cancer and UNC5;Eph receptors and their ligands,ephrins;Slit and its receptor,Robo;repulsive guidance molecules and their receptor,neogenin;Wnt proteins and their receptor,Frizzled;and protocadherins.Localized Netrin-1 at the injury site inhibits motor axon regeneration after adult spinal cord injury while promoting oligodendrocyte growth.Slit2 enhances synapse formation in the injured spinal cord of rats.EphA7 regulates acute apoptosis in the early pathophysiological stages of spinal cord injury,while ephrinA1 plays a role in the nervous system’s injury response,with its reduced expression leading to impaired motor function in rats.EphA3 is upregulated following spinal cord injury,promoting an inhibitory environment for axonal regeneration.After spinal cord injury,bidirectional activation of ephrinB2 and EphB2 in astrocytes and fibroblasts results in the formation of a dense astrocyte-meningeal fibroblast scar.EphB1/ephrinB1 signaling mediates pain processing in spinal cord injury by regulating calpain-1 and caspase-3 in neurons.EphB3 expression increases in white matter after spinal cord injury,further inhibiting axon regeneration.Sema3A,expressed by neurons and fibroblasts in the scar surrounding the injury,inhibits motor neuron and sensory nerve growth after spinal cord injury.Sema4D suppresses neuronal axon myelination and axon regeneration,while its inhibition significantly enhances axon regeneration and motor recovery.Sema7A is involved in glial scar formation and may influence serotonin channel remodeling,thereby affecting motor coordination.Given these findings,the local or systemic application of neuronal guidance proteins represents a promising avenue for spinal cord injury treatment.展开更多
Autism Spectrum Disorder(ASD)is marked by early-onset neurodevelopmental anomalies,yet the tem-poral dynamics of genetic contributions to these processes remain insufficiently understood.This study aimed to elu-cidate...Autism Spectrum Disorder(ASD)is marked by early-onset neurodevelopmental anomalies,yet the tem-poral dynamics of genetic contributions to these processes remain insufficiently understood.This study aimed to elu-cidate the role of the Shank3 gene,known to be associated with monogenic causes of autism,in early developmental processes to inform the timing and mechanisms for poten-tial interventions for ASD.Utilizing the Shank3B knockout(KO)mouse model,we examined Shank3 expression and its impact on neuronal maturation through Golgi staining for dendritic morphology and electrophysiological recordings to measure synaptic function in the anterior cingulate cortex(ACC)across different postnatal stages.Our longitudinal analysis revealed that,while Shank3B KO mice displayed normal neuronal morphology at one week postnatal,signifi-cant impairments in dendritic growth and synaptic activity emerged by two to three weeks.These findings highlight the critical developmental window during which Shank3 is essential for neuronal and synaptic maturation in the ACC.展开更多
The process of neurite outgrowth and branching is a crucial aspect of neuronal development and regeneration.Axons and dendrites,sometimes referred to as neurites,are extensions of a neuron's cellular body that are...The process of neurite outgrowth and branching is a crucial aspect of neuronal development and regeneration.Axons and dendrites,sometimes referred to as neurites,are extensions of a neuron's cellular body that are used to start networks.Here we explored the effects of diethyl(3,4-dihydroxyphenethylamino)(quinolin-4-yl)methylphosphonate(DDQ)on neurite developmental features in HT22 neuronal cells.In this work,we examined the protective effects of DDQ on neuronal processes and synaptic outgrowth in differentiated HT22cells expressing mutant Tau(mTau)cDNA.To investigate DDQ chara cteristics,cell viability,biochemical,molecular,western blotting,and immunocytochemistry were used.Neurite outgrowth is evaluated through the segmentation and measurement of neural processes.These neural processes can be seen and measured with a fluorescence microscope by manually tracing and measuring the length of the neurite growth.These neuronal processes can be observed and quantified with a fluorescent microscope by manually tracing and measuring the length of the neuronal HT22.DDQ-treated mTau-HT22 cells(HT22 cells transfected with cDNA mutant Tau)were seen to display increased levels of synaptophysin,MAP-2,andβ-tubulin.Additionally,we confirmed and noted reduced levels of both total and p-Tau,as well as elevated levels of microtubule-associated protein 2,β-tubulin,synaptophysin,vesicular acetylcholine transporter,and the mitochondrial biogenesis protein-pe roxisome prolife rator-activated receptor-gamma coactivator-1α.In mTa u-expressed HT22 neurons,we observed DDQ enhanced the neurite characteristics and improved neurite development through increased synaptic outgrowth.Our findings conclude that mTa u-HT22(Alzheimer's disease)cells treated with DDQ have functional neurite developmental chara cteristics.The key finding is that,in mTa u-HT22 cells,DDQ preserves neuronal structure and may even enhance nerve development function with mTa u inhibition.展开更多
Alzheimer's disease is characterized by deposition of amyloid-β,which forms extracellular neuritic plaques,and accumulation of hyperphosphorylated tau,which aggregates to form intraneuronal neurofibrillary tangle...Alzheimer's disease is characterized by deposition of amyloid-β,which forms extracellular neuritic plaques,and accumulation of hyperphosphorylated tau,which aggregates to form intraneuronal neurofibrillary tangles,in the brain.The NLRP3 inflammasome may play a role in the transition from amyloid-βdeposition to tau phosphorylation and aggregation.Because NLRP3 is primarily found in brain microglia,and tau is predominantly located in neurons,it has been suggested that NLRP3 expressed by microglia indirectly triggers tau phosphorylation by upregulating the expression of pro-inflammatory cytokines.Here,we found that neurons also express NLRP3 in vitro and in vivo,and that neuronal NLRP3 regulates tau phosphorylation.Using biochemical methods,we mapped the minimal NLRP3 promoter and identified FUBP3 as a transcription factor regulating NLRP3 expression in neurons.In primary neurons and the neuroblastoma cell line Neuro2A,FUBP3 is required for endogenous NLRP3 expression and tau phosphorylation only when amyloid-βis present.In the brains of aged wild-type mice and a mouse model of Alzheimer's disease,FUBP3 expression was markedly increased in cortical neurons.Transcriptome analysis suggested that FUBP3 plays a role in neuron-mediated immune responses.We also found that FUBP3 trimmed the 5′end of DNA fragments that it bound,implying that FUBP3 functions in stress-induced responses.These findings suggest that neuronal NLRP3 may be more directly involved in the amyloid-β-to–phospho-tau transition than microglial NLRP3,and that amyloid-βfundamentally alters the regulatory mechanism of NLRP3 expression in neurons.Given that FUBP3 was only expressed at low levels in young wild-type mice and was strongly upregulated in the brains of aged mice and Alzheimer's disease mice,FUBP3 could be a safe therapeutic target for preventing Alzheimer's disease progression.展开更多
Background:C1QL3 is widely expressed in the brain and is specifically produced by a subset of excitatory neurons.However,its function is still not clear.We established C1ql3-deficient rats to investigate the role of C...Background:C1QL3 is widely expressed in the brain and is specifically produced by a subset of excitatory neurons.However,its function is still not clear.We established C1ql3-deficient rats to investigate the role of C1QL3 in the brain.Methods:C1ql3 knockout(KO)rats were generated using CRISPR/Cas9.C1ql3 KO was determined by polymerase chain reaction(PCR),DNA sequencing,and western blot-ting.Microglia morphology and cytokine expression with or without lipopolysaccha-ride(LPS)stimulus were analyzed using immunohistochemistry and real-time PCR.The brain structure changes in KO rats were examined using magnetic resonance imaging.Neuronal architecture alteration was analyzed by performing Golgi staining.Behavior was evaluated using the open field test,Morris water maze test,and Y maze test.Results:C1ql3 KO significantly increased the number of ramified microglia and decreased the number of hypertrophic microglia,whereas C1ql3 KO did not in-fluence the expression of pro-inflammatory factors and anti-inflammatory factors except IL-10.C1ql3 KO brains had more amoeboid microglia types and higher Arg-1 expression compared with the WT rats after LPS stimulation.The brain weights and HPC sizes of C1ql3 KO rats did not differ from WT rats.C1ql3 KO damaged neuronal integrity including neuron dendritic arbors and spine density.C1ql3 KO rats demonstrated an increase in spontaneous activity and an impairment in short working memory.Conclusions:C1ql3 KO not only interrupts the neuronal integrity but also affects the microglial activation,resulting in hyperactive behavior and impaired short memory in rats,which highlights the role of C1QL3 in the regulation of structure and function of both neuronal and microglial cells.展开更多
Deep learning networks are increasingly exploited in the field of neuronal soma segmentation.However,annotating dataset is also an expensive and time-consuming task.Unsupervised domain adaptation is an effective metho...Deep learning networks are increasingly exploited in the field of neuronal soma segmentation.However,annotating dataset is also an expensive and time-consuming task.Unsupervised domain adaptation is an effective method to mitigate the problem,which is able to learn an adaptive segmentation model by transferring knowledge from a rich-labeled source domain.In this paper,we propose a multi-level distribution alignment-based unsupervised domain adaptation network(MDA-Net)for segmentation of 3D neuronal soma images.Distribution alignment is performed in both feature space and output space.In the feature space,features from different scales are adaptively fused to enhance the feature extraction capability for small target somata and con-strained to be domain invariant by adversarial adaptation strategy.In the output space,local discrepancy maps that can reveal the spatial structures of somata are constructed on the predicted segmentation results.Then thedistribution alignment is performed on the local discrepancies maps across domains to obtain a superior discrepancy map in the target domain,achieving refined segmentation performance of neuronal somata.Additionally,after a period of distribution align-ment procedure,a portion of target samples with high confident pseudo-labels are selected as training data,which assist in learning a more adaptive segmentation network.We verified the superiority of the proposed algorithm by comparing several domain adaptation networks on two 3D mouse brain neuronal somata datasets and one macaque brain neuronal soma dataset.展开更多
Objective NMDA receptor channel plays an important role in the pathophysiological process of traumatic brain injury （TBI）. The present study aims to study the pathological mechanism of TBI and the impairment of lear...Objective NMDA receptor channel plays an important role in the pathophysiological process of traumatic brain injury （TBI）. The present study aims to study the pathological mechanism of TBI and the impairment of learning and memory after TBI, and to investigate the mechanism of the protective effect of NMDA receptor antagonist MK-801 on learning and memory disorder after TBI. Methods Forty Sprague-Dawley rats （weighing approximately 200 g） were randomized into 5 groups （n = 8 in each group）： control group, model group, low-dose group （MK-801 0.5 mg/kg）, middle-dose group （MK-801 2 mg/kg）, and high-dose group （MK-801 10 mg/kg）. TBI model was established using a weight-drop head injury mode. After 2-month drug treatment, learning and memory ability was evaluated by using Morris water maze test. Then the animals were sacrificed, and brain tissues were taken out for morphological and immunohistochemical assays. Results The ability of learning and memory was significantly impaired in the TBI model animals. Besides, the neuronal caspase-3 expression, neuronal nitric oxide synthase （nNOS）-positive neurons and OX-42-positive microglia were all increased in TBI animals. Meanwhile, the number of neuron synapses was decreased, and vacuoles degeneration could be observed in mitochondria. After MK-801 treatment at 3 different dosages, the ability of learning and memory was markedly improved, as compared to that of the TBI model animals. Moreover, neuronal caspase-3 expression, OX-42-positive microglia and nNOS-positive neurons were all significantly decreased. Meanwhile, the mitochondria degeneration was greatly inhibited. Conclusion MK-801 could significantly inhibit the degeneration and apoptosis of neurons in damaged brain areas. It could also inhibit TBI-induced increase in nNOS-positive neurons and OX-42-positive microglia. Impairment in learning and memory in TBI animals could be repaired by treatment with MK-801.展开更多
To perform various functions in the body,skeletal muscle is controlled and coordinated as a whole by nerves.However,there has been little research into whether the nerve control characteristics of different muscles ar...To perform various functions in the body,skeletal muscle is controlled and coordinated as a whole by nerves.However,there has been little research into whether the nerve control characteristics of different muscles are different,and the importance of these potential differences.In the present study,we used a three-dimensional imaging of solvent-cleared organ-compatible multi-tracer technique to explore the spatial distribution patterns of sensory and sympathetic neurons that innervate limb muscles.We integrated transcriptome sequencing datasets from mouse limb muscles in public databases and performed correlation analysis with neuronal spatial distribution data to reveal the unique effects of different types of neurons on muscle functional pathways.In terms of spatial distribution patterns,sympathetic neurons exhibited a more concentrated distribution than sensory and motor neurons.In addition,the neuronal innervation of limb muscles exhibited four different characteristics:sympathetic neuron-rich muscle,sensory neuron-rich muscle,neuron-sparse muscle,and motor neuron-rich muscle.Sensory neuron density was mainly associated with muscle contractile structure and cell pH,whereas sympathetic neuron density was associated with protein kinase activity,muscle vasculature,muscle calcium-dependent protein kinase activity,lipid transport,and vesicle release.Motor neuron density was mainly associated with protein kinase activity,cell adhesion,oxidoreductase activity,and exocytosis.These findings may contribute to a deeper understanding of how nerves cooperate to endow muscles with diverse physiological functions,thereby providing new insights and experimental evidence for the treatment of various neuromuscular diseases.展开更多
Functional neurological recovery remains the primary objective when treating ischemic stroke.However,current therapeutic approaches often fall short of achieving optimal outcomes.One of the most significant challenges...Functional neurological recovery remains the primary objective when treating ischemic stroke.However,current therapeutic approaches often fall short of achieving optimal outcomes.One of the most significant challenges in stroke treatment is the effective delivery of neuroprotective agents across the blood–brain barrier to ischemic regions within the brain.The blood–brain barrier,while essential for protecting the brain from harmful substances,also restricts the passage of many therapeutic compounds,thus limiting their efficacy.In this review,we summarizes the emerging role of nanoparticle-based therapies for the treatment of ischemic stroke and investigate their potential to revolutionize drug delivery,enhance neuroprotection,and promote functional recovery.Recent advancements in nanotechnology have led to the development of engineered nanoparticles specifically designed to overcome the blood–brain barrier,thus enabling the targeted delivery of therapeutic agents directly to the affected brain areas.Preclinical studies have demonstrated the remarkable potential of nanoparticle-based therapies to activate key neuroprotective pathways,such as the phosphoinositide 3-kinase/protein kinase B/c AMP response element-binding protein signaling cascade,which is crucial for neuronal survival,synaptic plasticity,and post-stroke recovery.By modulating these pathways,nanoparticles could mitigate neuronal damage,reduce inflammation,and promote tissue repair.Furthermore,nanoparticles offer a unique advantage by enabling multimodal therapeutic strategies that simultaneously target multiple pathological mechanisms of ischemic stroke,including oxidative stress,neuroinflammation,and apoptosis.This multifaceted approach enhances the overall efficacy of treatment,addressing the complex and interconnected processes that contribute to stroke-related brain injury.Surface modifications,such as functionalization with specific ligands or targeting molecules,further improve the precision of drug delivery,enhance targeting specificity,and prolong systemic circulation,thereby optimizing therapeutic outcomes.Nanoparticlebased therapeutics represent a paradigm shift for the management of stroke and provide a promising avenue for reducing post-stroke disability and improving the outcomes of long-term rehabilitation.By combining targeted drug delivery with the ability to modulate critical neuroprotective pathways,nanoparticles hold the potential to transform the treatment landscape for ischemic stroke.However,while preclinical data are highly encouraging,significant challenges remain in translating these advancements into clinical practice.Further research is needed to refine nanoparticle designs,optimize their safety profiles,and ensure their scalability for widespread application.Rigorous clinical trials are essential to validate their efficacy,assess long-term biocompatibility,and address potential off-target effects.The integration of interdisciplinary approaches,combining insights from nanotechnology,neuroscience,and pharmacology,will be critical if we are to overcome these challenges.Ultimately,nanoparticle-based therapies offer a foundation for innovative,precision-based treatments that could significantly improve outcomes for stroke patients,thus paving the way for a new era in stroke care and neurological rehabilitation.展开更多
Phosphodiesterase 4 is a key enzyme involved in the regulation of cell signal transduction,but its role in subarachnoid hemorrhage remains unclear.Neuronal pyroptosis has been reported to be involved in early brain in...Phosphodiesterase 4 is a key enzyme involved in the regulation of cell signal transduction,but its role in subarachnoid hemorrhage remains unclear.Neuronal pyroptosis has been reported to be involved in early brain injury after subarachnoid hemorrhage.This study aimed to investigate whether phosphodiesterase 4 contributes to early brain injury after subarachnoid hemorrhage by mediating neuronal pyroptosis and its related mechanisms.Endovascular perforation of male C57BL/6J mice was performed to model subarachnoid hemorrhage in vivo,and oxyhemoglobin was added to the culture medium of primary neurons to model subarachnoid hemorrhage in vitro.A phosphodiesterase 4-specific inhibitor,etazolate,was intraperitoneally injected 30 minutes after subarachnoid hemorrhage induction.Small interfering RNA(siRNA)was administered intracerebroventricularly 72 hours before subarachnoid hemorrhage to achieve genetic knockdown of phosphodiesterase 4.To investigate the mechanism,a nucleotide-binding oligomerization domain-like receptor pyrin domain containing 3(NLRP3)-specific agonist,nigericin,was intracerebroventricularly injected 60 minutes before subarachnoid hemorrhage.Neuronal phosphodiesterase 4 expression increased after subarachnoid hemorrhage and reached the highest point at 24 hours.Etazolate treatment reduced neurological deficits and brain edema in mice,alleviated neuronal pyroptosis and inflammatory response,and improved neuronal injury.Treatment with phosphodiesterase 4 siRNA had the same neuroprotective effects as etazolate.Mechanistically,phosphodiesterase 4 triggered the nuclear factor kappa-B pathway,and simultaneously caused lysosomal and mitochondrial dysfunction after subarachnoid hemorrhage,which promoted NLRP3 inflammasome activation and induced neuronal pyroptosis.Blocking of phosphodiesterase 4 inhibited the nuclear factor kappa-B pathway,and improved lysosome and mitochondrial function.Activation of NLRP3 reversed the neuroprotective effects of etazolate without affecting phosphodiesterase 4 expression.Together,the results indicate that phosphodiesterase 4 regulates NLRP3-mediated neuronal pyroptosis in early brain injury after subarachnoid hemorrhage.Phosphodiesterase 4 may be a potential therapeutic molecular target for subarachnoid hemorrhage.展开更多
基金supported by Shenzhen University General Hospital Scientific Research Project,No.SUGH2019QD002Shenzhen Science and Technology Development Foundation,No.20220810173216001(both to ZS).
文摘Spinal cord injury is a severe neurological condition with limited neuronal regeneration and functional recovery.Currently,no effective treatments exist to improve spinal cord injury prognosis.Neuronal guidance proteins are a diverse group of molecules that play crucial roles in axon and dendrite growth during nervous system development.Increasing evidence highlights their regulatory functions in spinal cord injury.This review provides a brief overview of the modulation patterns of key neuronal guidance proteins in neuronal axon growth during nervous system formation and subsequently focuses on their roles in neuronal regeneration and functional recovery following spinal cord injury.Neuronal guidance proteins include,but are not limited to,semaphorins and their receptors,plexins;netrins and their receptors,deleted in colorectal cancer and UNC5;Eph receptors and their ligands,ephrins;Slit and its receptor,Robo;repulsive guidance molecules and their receptor,neogenin;Wnt proteins and their receptor,Frizzled;and protocadherins.Localized Netrin-1 at the injury site inhibits motor axon regeneration after adult spinal cord injury while promoting oligodendrocyte growth.Slit2 enhances synapse formation in the injured spinal cord of rats.EphA7 regulates acute apoptosis in the early pathophysiological stages of spinal cord injury,while ephrinA1 plays a role in the nervous system’s injury response,with its reduced expression leading to impaired motor function in rats.EphA3 is upregulated following spinal cord injury,promoting an inhibitory environment for axonal regeneration.After spinal cord injury,bidirectional activation of ephrinB2 and EphB2 in astrocytes and fibroblasts results in the formation of a dense astrocyte-meningeal fibroblast scar.EphB1/ephrinB1 signaling mediates pain processing in spinal cord injury by regulating calpain-1 and caspase-3 in neurons.EphB3 expression increases in white matter after spinal cord injury,further inhibiting axon regeneration.Sema3A,expressed by neurons and fibroblasts in the scar surrounding the injury,inhibits motor neuron and sensory nerve growth after spinal cord injury.Sema4D suppresses neuronal axon myelination and axon regeneration,while its inhibition significantly enhances axon regeneration and motor recovery.Sema7A is involved in glial scar formation and may influence serotonin channel remodeling,thereby affecting motor coordination.Given these findings,the local or systemic application of neuronal guidance proteins represents a promising avenue for spinal cord injury treatment.
基金supported by the Natural Science Foundation of China(32394032,82201699,and 82221001)the Natural Science Foundation of Zhejiang Province(LTGD24H250001)+1 种基金the Kay R&D Program of Shaanxi Province(2023-YBSF-093),the Young Talent Fund of University Association for Science and Technology in Shaanxi(20220306)the Joint Founding Project of Innovation Research Institute,Xijing Hospital(LHJJ24JH02).
文摘Autism Spectrum Disorder(ASD)is marked by early-onset neurodevelopmental anomalies,yet the tem-poral dynamics of genetic contributions to these processes remain insufficiently understood.This study aimed to elu-cidate the role of the Shank3 gene,known to be associated with monogenic causes of autism,in early developmental processes to inform the timing and mechanisms for poten-tial interventions for ASD.Utilizing the Shank3B knockout(KO)mouse model,we examined Shank3 expression and its impact on neuronal maturation through Golgi staining for dendritic morphology and electrophysiological recordings to measure synaptic function in the anterior cingulate cortex(ACC)across different postnatal stages.Our longitudinal analysis revealed that,while Shank3B KO mice displayed normal neuronal morphology at one week postnatal,signifi-cant impairments in dendritic growth and synaptic activity emerged by two to three weeks.These findings highlight the critical developmental window during which Shank3 is essential for neuronal and synaptic maturation in the ACC.
基金supported by NIH grants AG079264(to PHR)and AG071560(to APR)。
文摘The process of neurite outgrowth and branching is a crucial aspect of neuronal development and regeneration.Axons and dendrites,sometimes referred to as neurites,are extensions of a neuron's cellular body that are used to start networks.Here we explored the effects of diethyl(3,4-dihydroxyphenethylamino)(quinolin-4-yl)methylphosphonate(DDQ)on neurite developmental features in HT22 neuronal cells.In this work,we examined the protective effects of DDQ on neuronal processes and synaptic outgrowth in differentiated HT22cells expressing mutant Tau(mTau)cDNA.To investigate DDQ chara cteristics,cell viability,biochemical,molecular,western blotting,and immunocytochemistry were used.Neurite outgrowth is evaluated through the segmentation and measurement of neural processes.These neural processes can be seen and measured with a fluorescence microscope by manually tracing and measuring the length of the neurite growth.These neuronal processes can be observed and quantified with a fluorescent microscope by manually tracing and measuring the length of the neuronal HT22.DDQ-treated mTau-HT22 cells(HT22 cells transfected with cDNA mutant Tau)were seen to display increased levels of synaptophysin,MAP-2,andβ-tubulin.Additionally,we confirmed and noted reduced levels of both total and p-Tau,as well as elevated levels of microtubule-associated protein 2,β-tubulin,synaptophysin,vesicular acetylcholine transporter,and the mitochondrial biogenesis protein-pe roxisome prolife rator-activated receptor-gamma coactivator-1α.In mTa u-expressed HT22 neurons,we observed DDQ enhanced the neurite characteristics and improved neurite development through increased synaptic outgrowth.Our findings conclude that mTa u-HT22(Alzheimer's disease)cells treated with DDQ have functional neurite developmental chara cteristics.The key finding is that,in mTa u-HT22 cells,DDQ preserves neuronal structure and may even enhance nerve development function with mTa u inhibition.
基金supported by a grant from Key Laboratory of Alzheimer's Disease of Zhejiang Province,Institute of Aging,Wenzhou Medical University,No.ZJAD-2021002(to ZW)。
文摘Alzheimer's disease is characterized by deposition of amyloid-β,which forms extracellular neuritic plaques,and accumulation of hyperphosphorylated tau,which aggregates to form intraneuronal neurofibrillary tangles,in the brain.The NLRP3 inflammasome may play a role in the transition from amyloid-βdeposition to tau phosphorylation and aggregation.Because NLRP3 is primarily found in brain microglia,and tau is predominantly located in neurons,it has been suggested that NLRP3 expressed by microglia indirectly triggers tau phosphorylation by upregulating the expression of pro-inflammatory cytokines.Here,we found that neurons also express NLRP3 in vitro and in vivo,and that neuronal NLRP3 regulates tau phosphorylation.Using biochemical methods,we mapped the minimal NLRP3 promoter and identified FUBP3 as a transcription factor regulating NLRP3 expression in neurons.In primary neurons and the neuroblastoma cell line Neuro2A,FUBP3 is required for endogenous NLRP3 expression and tau phosphorylation only when amyloid-βis present.In the brains of aged wild-type mice and a mouse model of Alzheimer's disease,FUBP3 expression was markedly increased in cortical neurons.Transcriptome analysis suggested that FUBP3 plays a role in neuron-mediated immune responses.We also found that FUBP3 trimmed the 5′end of DNA fragments that it bound,implying that FUBP3 functions in stress-induced responses.These findings suggest that neuronal NLRP3 may be more directly involved in the amyloid-β-to–phospho-tau transition than microglial NLRP3,and that amyloid-βfundamentally alters the regulatory mechanism of NLRP3 expression in neurons.Given that FUBP3 was only expressed at low levels in young wild-type mice and was strongly upregulated in the brains of aged mice and Alzheimer's disease mice,FUBP3 could be a safe therapeutic target for preventing Alzheimer's disease progression.
基金The present work was supported by the National Natural Science Foundation(31970508)the National Key Research and Development Program of China(2022YFF0710702).
文摘Background:C1QL3 is widely expressed in the brain and is specifically produced by a subset of excitatory neurons.However,its function is still not clear.We established C1ql3-deficient rats to investigate the role of C1QL3 in the brain.Methods:C1ql3 knockout(KO)rats were generated using CRISPR/Cas9.C1ql3 KO was determined by polymerase chain reaction(PCR),DNA sequencing,and western blot-ting.Microglia morphology and cytokine expression with or without lipopolysaccha-ride(LPS)stimulus were analyzed using immunohistochemistry and real-time PCR.The brain structure changes in KO rats were examined using magnetic resonance imaging.Neuronal architecture alteration was analyzed by performing Golgi staining.Behavior was evaluated using the open field test,Morris water maze test,and Y maze test.Results:C1ql3 KO significantly increased the number of ramified microglia and decreased the number of hypertrophic microglia,whereas C1ql3 KO did not in-fluence the expression of pro-inflammatory factors and anti-inflammatory factors except IL-10.C1ql3 KO brains had more amoeboid microglia types and higher Arg-1 expression compared with the WT rats after LPS stimulation.The brain weights and HPC sizes of C1ql3 KO rats did not differ from WT rats.C1ql3 KO damaged neuronal integrity including neuron dendritic arbors and spine density.C1ql3 KO rats demonstrated an increase in spontaneous activity and an impairment in short working memory.Conclusions:C1ql3 KO not only interrupts the neuronal integrity but also affects the microglial activation,resulting in hyperactive behavior and impaired short memory in rats,which highlights the role of C1QL3 in the regulation of structure and function of both neuronal and microglial cells.
基金supported by the Fund of Key Laboratory of Biomedical Engineering of Hainan Province(No.BME20240001)the STI2030-Major Projects(No.2021ZD0200104)the National Natural Science Foundations of China under Grant 61771437.
文摘Deep learning networks are increasingly exploited in the field of neuronal soma segmentation.However,annotating dataset is also an expensive and time-consuming task.Unsupervised domain adaptation is an effective method to mitigate the problem,which is able to learn an adaptive segmentation model by transferring knowledge from a rich-labeled source domain.In this paper,we propose a multi-level distribution alignment-based unsupervised domain adaptation network(MDA-Net)for segmentation of 3D neuronal soma images.Distribution alignment is performed in both feature space and output space.In the feature space,features from different scales are adaptively fused to enhance the feature extraction capability for small target somata and con-strained to be domain invariant by adversarial adaptation strategy.In the output space,local discrepancy maps that can reveal the spatial structures of somata are constructed on the predicted segmentation results.Then thedistribution alignment is performed on the local discrepancies maps across domains to obtain a superior discrepancy map in the target domain,achieving refined segmentation performance of neuronal somata.Additionally,after a period of distribution align-ment procedure,a portion of target samples with high confident pseudo-labels are selected as training data,which assist in learning a more adaptive segmentation network.We verified the superiority of the proposed algorithm by comparing several domain adaptation networks on two 3D mouse brain neuronal somata datasets and one macaque brain neuronal soma dataset.
基金supported by the grants from Nanjing Military Medical Science and Technology Innovation Project (No. 08MA007)
文摘Objective NMDA receptor channel plays an important role in the pathophysiological process of traumatic brain injury （TBI）. The present study aims to study the pathological mechanism of TBI and the impairment of learning and memory after TBI, and to investigate the mechanism of the protective effect of NMDA receptor antagonist MK-801 on learning and memory disorder after TBI. Methods Forty Sprague-Dawley rats （weighing approximately 200 g） were randomized into 5 groups （n = 8 in each group）： control group, model group, low-dose group （MK-801 0.5 mg/kg）, middle-dose group （MK-801 2 mg/kg）, and high-dose group （MK-801 10 mg/kg）. TBI model was established using a weight-drop head injury mode. After 2-month drug treatment, learning and memory ability was evaluated by using Morris water maze test. Then the animals were sacrificed, and brain tissues were taken out for morphological and immunohistochemical assays. Results The ability of learning and memory was significantly impaired in the TBI model animals. Besides, the neuronal caspase-3 expression, neuronal nitric oxide synthase （nNOS）-positive neurons and OX-42-positive microglia were all increased in TBI animals. Meanwhile, the number of neuron synapses was decreased, and vacuoles degeneration could be observed in mitochondria. After MK-801 treatment at 3 different dosages, the ability of learning and memory was markedly improved, as compared to that of the TBI model animals. Moreover, neuronal caspase-3 expression, OX-42-positive microglia and nNOS-positive neurons were all significantly decreased. Meanwhile, the mitochondria degeneration was greatly inhibited. Conclusion MK-801 could significantly inhibit the degeneration and apoptosis of neurons in damaged brain areas. It could also inhibit TBI-induced increase in nNOS-positive neurons and OX-42-positive microglia. Impairment in learning and memory in TBI animals could be repaired by treatment with MK-801.
基金supported by the National Natural Science Foundation of China,No.82072162(to XY).
文摘To perform various functions in the body,skeletal muscle is controlled and coordinated as a whole by nerves.However,there has been little research into whether the nerve control characteristics of different muscles are different,and the importance of these potential differences.In the present study,we used a three-dimensional imaging of solvent-cleared organ-compatible multi-tracer technique to explore the spatial distribution patterns of sensory and sympathetic neurons that innervate limb muscles.We integrated transcriptome sequencing datasets from mouse limb muscles in public databases and performed correlation analysis with neuronal spatial distribution data to reveal the unique effects of different types of neurons on muscle functional pathways.In terms of spatial distribution patterns,sympathetic neurons exhibited a more concentrated distribution than sensory and motor neurons.In addition,the neuronal innervation of limb muscles exhibited four different characteristics:sympathetic neuron-rich muscle,sensory neuron-rich muscle,neuron-sparse muscle,and motor neuron-rich muscle.Sensory neuron density was mainly associated with muscle contractile structure and cell pH,whereas sympathetic neuron density was associated with protein kinase activity,muscle vasculature,muscle calcium-dependent protein kinase activity,lipid transport,and vesicle release.Motor neuron density was mainly associated with protein kinase activity,cell adhesion,oxidoreductase activity,and exocytosis.These findings may contribute to a deeper understanding of how nerves cooperate to endow muscles with diverse physiological functions,thereby providing new insights and experimental evidence for the treatment of various neuromuscular diseases.
基金supported by the National Natural Science Foundations of China,Nos.82272163,82472164(both MF)。
文摘Functional neurological recovery remains the primary objective when treating ischemic stroke.However,current therapeutic approaches often fall short of achieving optimal outcomes.One of the most significant challenges in stroke treatment is the effective delivery of neuroprotective agents across the blood–brain barrier to ischemic regions within the brain.The blood–brain barrier,while essential for protecting the brain from harmful substances,also restricts the passage of many therapeutic compounds,thus limiting their efficacy.In this review,we summarizes the emerging role of nanoparticle-based therapies for the treatment of ischemic stroke and investigate their potential to revolutionize drug delivery,enhance neuroprotection,and promote functional recovery.Recent advancements in nanotechnology have led to the development of engineered nanoparticles specifically designed to overcome the blood–brain barrier,thus enabling the targeted delivery of therapeutic agents directly to the affected brain areas.Preclinical studies have demonstrated the remarkable potential of nanoparticle-based therapies to activate key neuroprotective pathways,such as the phosphoinositide 3-kinase/protein kinase B/c AMP response element-binding protein signaling cascade,which is crucial for neuronal survival,synaptic plasticity,and post-stroke recovery.By modulating these pathways,nanoparticles could mitigate neuronal damage,reduce inflammation,and promote tissue repair.Furthermore,nanoparticles offer a unique advantage by enabling multimodal therapeutic strategies that simultaneously target multiple pathological mechanisms of ischemic stroke,including oxidative stress,neuroinflammation,and apoptosis.This multifaceted approach enhances the overall efficacy of treatment,addressing the complex and interconnected processes that contribute to stroke-related brain injury.Surface modifications,such as functionalization with specific ligands or targeting molecules,further improve the precision of drug delivery,enhance targeting specificity,and prolong systemic circulation,thereby optimizing therapeutic outcomes.Nanoparticlebased therapeutics represent a paradigm shift for the management of stroke and provide a promising avenue for reducing post-stroke disability and improving the outcomes of long-term rehabilitation.By combining targeted drug delivery with the ability to modulate critical neuroprotective pathways,nanoparticles hold the potential to transform the treatment landscape for ischemic stroke.However,while preclinical data are highly encouraging,significant challenges remain in translating these advancements into clinical practice.Further research is needed to refine nanoparticle designs,optimize their safety profiles,and ensure their scalability for widespread application.Rigorous clinical trials are essential to validate their efficacy,assess long-term biocompatibility,and address potential off-target effects.The integration of interdisciplinary approaches,combining insights from nanotechnology,neuroscience,and pharmacology,will be critical if we are to overcome these challenges.Ultimately,nanoparticle-based therapies offer a foundation for innovative,precision-based treatments that could significantly improve outcomes for stroke patients,thus paving the way for a new era in stroke care and neurological rehabilitation.
基金supported by the National Natural Science Foundation of China,No.81870927(to ZH)the Natural Science Foundation Project ofChongqing Science and Technology Commission,No.CSTB2023NSCQ-MSX0112(to ZH).
文摘Phosphodiesterase 4 is a key enzyme involved in the regulation of cell signal transduction,but its role in subarachnoid hemorrhage remains unclear.Neuronal pyroptosis has been reported to be involved in early brain injury after subarachnoid hemorrhage.This study aimed to investigate whether phosphodiesterase 4 contributes to early brain injury after subarachnoid hemorrhage by mediating neuronal pyroptosis and its related mechanisms.Endovascular perforation of male C57BL/6J mice was performed to model subarachnoid hemorrhage in vivo,and oxyhemoglobin was added to the culture medium of primary neurons to model subarachnoid hemorrhage in vitro.A phosphodiesterase 4-specific inhibitor,etazolate,was intraperitoneally injected 30 minutes after subarachnoid hemorrhage induction.Small interfering RNA(siRNA)was administered intracerebroventricularly 72 hours before subarachnoid hemorrhage to achieve genetic knockdown of phosphodiesterase 4.To investigate the mechanism,a nucleotide-binding oligomerization domain-like receptor pyrin domain containing 3(NLRP3)-specific agonist,nigericin,was intracerebroventricularly injected 60 minutes before subarachnoid hemorrhage.Neuronal phosphodiesterase 4 expression increased after subarachnoid hemorrhage and reached the highest point at 24 hours.Etazolate treatment reduced neurological deficits and brain edema in mice,alleviated neuronal pyroptosis and inflammatory response,and improved neuronal injury.Treatment with phosphodiesterase 4 siRNA had the same neuroprotective effects as etazolate.Mechanistically,phosphodiesterase 4 triggered the nuclear factor kappa-B pathway,and simultaneously caused lysosomal and mitochondrial dysfunction after subarachnoid hemorrhage,which promoted NLRP3 inflammasome activation and induced neuronal pyroptosis.Blocking of phosphodiesterase 4 inhibited the nuclear factor kappa-B pathway,and improved lysosome and mitochondrial function.Activation of NLRP3 reversed the neuroprotective effects of etazolate without affecting phosphodiesterase 4 expression.Together,the results indicate that phosphodiesterase 4 regulates NLRP3-mediated neuronal pyroptosis in early brain injury after subarachnoid hemorrhage.Phosphodiesterase 4 may be a potential therapeutic molecular target for subarachnoid hemorrhage.
