目的探讨黑皮质素受体激动剂(MT-Ⅱ)改善SH3和多个锚蛋白重复结构域3(Shank3)基因缺陷孤独症模型鼠社交缺陷的作用机制。方法利用Shank3干扰慢病毒和空载慢病毒注射至仔鼠右侧脑室构建Shank3模型鼠和空载鼠各18只,Shank3组随机分为Shank...目的探讨黑皮质素受体激动剂(MT-Ⅱ)改善SH3和多个锚蛋白重复结构域3(Shank3)基因缺陷孤独症模型鼠社交缺陷的作用机制。方法利用Shank3干扰慢病毒和空载慢病毒注射至仔鼠右侧脑室构建Shank3模型鼠和空载鼠各18只,Shank3组随机分为Shank3+Sal(Sh3-Sal)组9只和Shank3+MT-Ⅱ(Sh3-MT-Ⅱ)组9只,空载组随机分为空载+Sal(V-Sal)组9只和空载+MT-Ⅱ(V-MT-Ⅱ)组9只。V-MT-Ⅱ组和Sh3-MT-Ⅱ组于第28天腹腔注射3.3 m L/kg MT-Ⅱ,V-Sal组和Sh3-Sal组腹腔注射3.3 m L/kg 0.9%氯化钠溶液,通过旷场实验、理毛实验、三箱社交实验及Morris水迷宫实验评估其行为学改变;采用逆转录聚合酶链式反应(RT-PCR)和蛋白免疫印迹(Western blot)检测下丘脑催产素(OXT)、催产素受体(OXTR)及黑皮质素受体4(MC4R)的mRNA与蛋白表达水平。结果行为学结果显示,三箱社交实验中与陌生鼠1相比,Sh3-Sal组未表现出社交差异(P>0.05),而MT-Ⅱ干预后,Sh3-MT-Ⅱ组与陌生鼠2的社交时间显著增加,差异有统计学意义(P<0.01)。Morris水迷宫实验中与V-Sal组相比,Sh3-Sal组表现出显著的学习记忆障碍(P<0.05),而MTⅡ干预后,Sh3-MT-Ⅱ组学习记忆能力明显提高,差异有统计学意义(P<0.01)。旷场实验和理毛实验结果显示,与V-Sal组相比,Sh3-Sal组周边停留时间及理毛时间均显著增加,差异有统计学意义(P<0.01);MT-Ⅱ干预后,旷场中心停留时间及理毛行为与Sh3-Sal组无显著差异(P>0.05)。RT-PCR检测显示,与Sh3-Sal组相比,Sh3-MT-Ⅱ组OXT、OXTR和MC4R mRNA表达水平明显升高,差异有统计学意义(P<0.05);Western blot法检测显示,与Sh3-Sal组相比,Sh3-MT-Ⅱ组大鼠下丘脑OXT蛋白表达水平明显升高(P<0.05),与V-Sal组相比,Sh3-Sal组和Sh3-MT-Ⅱ组大鼠下丘脑SHANK3蛋白表达水平明显降低(P<0.05,P<0.01),而OXTR及MC4R蛋白表达水平无显著差异(P>0.05)。结论黑皮质素受体激动剂MT-Ⅱ可能通过激活下丘脑OXT系统改善Shank3缺陷孤独症模型鼠的社交障碍,提示靶向OXT/MC4R通路或为孤独症社交缺陷的潜在干预策略。展开更多
Children with autism often exhibit abnormalities in body weight,but the underlying mechanism remains unclear.SH3 and multiple ankyrin repeat domains protein 3(SHANK3),a scaffold protein of the postsynaptic density,has...Children with autism often exhibit abnormalities in body weight,but the underlying mechanism remains unclear.SH3 and multiple ankyrin repeat domains protein 3(SHANK3),a scaffold protein of the postsynaptic density,has been reported to be associated with autism.This study aimed to investigate whether and how SHANK3 influences body weight in the hypothalamic neuronal regulation of energy homeostasis.Adeno-associated viruses 9(AAV9)carrying CMV-Cre and Agrp-Cre were stereotactically injected to restore SHANK3 expression in the arcuate nucleus(ARC)and agouti-related peptide(AgRP)neurons,respectively.Agrp-Cre mice were injected with AAV9-p38αflox/flox to overexpress p38α.Activated p38αwas generated by mutating both D176A and F327S in p38α.Inactivated p38αwas constructed by mutating both T180A and Y182F in p38α.Metabolic analysis,immunoblotting,histological analysis,the glucose tolerance test,the insulin tolerance test,and body fat mass analysis were applied to investigate the underlying mechanisms by which SHANK3 regulates body weight.We reveal that SHANK3 regulates body weight via the p38αsignaling pathway in the AgRP neurons of the hypothalamus.Shank3 knockout(Shank3−/−)mice exhibit resistance to diet-induced obesity.Shank3 re-expression in the ARC or AgRP neurons increases body weight in Shank3 knock-in mice with an inverted allele(SKO).Overexpression or activation of p38αin AgRP neurons elicits resistance to diet-induced obesity.Inactivated p38αin AgRP neurons abolished the resistance to diet-induced obesity due to SHANK3 deficiency.Our findings suggest that the SHANK3-p38αsiganling pathway in AgRP neurons regulates body weight balance in autism,revealing a promising therapeutic target for obesity in children with autism.展开更多
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
Long noncoding RNA and microRNA are regulatory noncoding RNAs that are implicated in Alzheimer's disease, but the role of long noncoding RNA-associated competitive endogenous RNA has not been fully elucidated. The...Long noncoding RNA and microRNA are regulatory noncoding RNAs that are implicated in Alzheimer's disease, but the role of long noncoding RNA-associated competitive endogenous RNA has not been fully elucidated. The long noncoding RNA growth arrest-specific 5(GAS5) is a member of the 5′-terminal oligopyrimidine gene family that may be involved in neurological disorders, but its role in Alzheimer's disease remains unclear. This study aimed to investigate the function of GAS5 and construct a GAS5-associated competitive endogenous RNA network comprising potential targets. RNA sequencing results showed that GAS5 was upregulated in five familial Alzheimer's disease(5×FAD) mice, APPswe/PSEN1dE9(APP/PS1) mice, Alzheimer's disease-related APPswe cells, and serum from patients with Alzheimer's disease. Functional experiments with targeted overexpression and silencing demonstrated that GAS5 played a role in cognitive dysfunction and multiple Alzheimer's disease-associated pathologies, including tau hyperphosphorylation, amyloid-beta accumulation, and neuronal apoptosis. Mechanistic studies indicated that GAS5 acted as an endogenous sponge by competing for microRNA-23b-3p(miR-23b-3p) binding to regulate its targets glycogen synthase kinase 3beta(GSK-3β) and phosphatase and tensin homologue deleted on chromosome 10(PTEN) expression in an Argonaute 2-induced RNA silencing complex(RISC)-dependent manner. GAS5 inhibited miR-23b-3p-mediated GSK-3β and PTEN cascades with a feedforward PTEN/protein kinase B(Akt)/GSK-3β linkage. Furthermore, recovery of GAS5/miR-23b-3p/GSK-3β/PTEN pathways relieved Alzheimer's disease-like symptoms in vivo, indicated by the amelioration of spatial cognition, neuronal degeneration, amyloid-beta load, and tau phosphorylation. Together, these findings suggest that GAS5 promotes Alzheimer's disease pathogenesis. This study establishes the functional convergence of the GAS5/miR-23b-3p/GSK-3β/PTEN pathway on multiple pathologies, suggesting a candidate therapeutic target in Alzheimer's disease.展开更多
文摘目的探讨黑皮质素受体激动剂(MT-Ⅱ)改善SH3和多个锚蛋白重复结构域3(Shank3)基因缺陷孤独症模型鼠社交缺陷的作用机制。方法利用Shank3干扰慢病毒和空载慢病毒注射至仔鼠右侧脑室构建Shank3模型鼠和空载鼠各18只,Shank3组随机分为Shank3+Sal(Sh3-Sal)组9只和Shank3+MT-Ⅱ(Sh3-MT-Ⅱ)组9只,空载组随机分为空载+Sal(V-Sal)组9只和空载+MT-Ⅱ(V-MT-Ⅱ)组9只。V-MT-Ⅱ组和Sh3-MT-Ⅱ组于第28天腹腔注射3.3 m L/kg MT-Ⅱ,V-Sal组和Sh3-Sal组腹腔注射3.3 m L/kg 0.9%氯化钠溶液,通过旷场实验、理毛实验、三箱社交实验及Morris水迷宫实验评估其行为学改变;采用逆转录聚合酶链式反应(RT-PCR)和蛋白免疫印迹(Western blot)检测下丘脑催产素(OXT)、催产素受体(OXTR)及黑皮质素受体4(MC4R)的mRNA与蛋白表达水平。结果行为学结果显示,三箱社交实验中与陌生鼠1相比,Sh3-Sal组未表现出社交差异(P>0.05),而MT-Ⅱ干预后,Sh3-MT-Ⅱ组与陌生鼠2的社交时间显著增加,差异有统计学意义(P<0.01)。Morris水迷宫实验中与V-Sal组相比,Sh3-Sal组表现出显著的学习记忆障碍(P<0.05),而MTⅡ干预后,Sh3-MT-Ⅱ组学习记忆能力明显提高,差异有统计学意义(P<0.01)。旷场实验和理毛实验结果显示,与V-Sal组相比,Sh3-Sal组周边停留时间及理毛时间均显著增加,差异有统计学意义(P<0.01);MT-Ⅱ干预后,旷场中心停留时间及理毛行为与Sh3-Sal组无显著差异(P>0.05)。RT-PCR检测显示,与Sh3-Sal组相比,Sh3-MT-Ⅱ组OXT、OXTR和MC4R mRNA表达水平明显升高,差异有统计学意义(P<0.05);Western blot法检测显示,与Sh3-Sal组相比,Sh3-MT-Ⅱ组大鼠下丘脑OXT蛋白表达水平明显升高(P<0.05),与V-Sal组相比,Sh3-Sal组和Sh3-MT-Ⅱ组大鼠下丘脑SHANK3蛋白表达水平明显降低(P<0.05,P<0.01),而OXTR及MC4R蛋白表达水平无显著差异(P>0.05)。结论黑皮质素受体激动剂MT-Ⅱ可能通过激活下丘脑OXT系统改善Shank3缺陷孤独症模型鼠的社交障碍,提示靶向OXT/MC4R通路或为孤独症社交缺陷的潜在干预策略。
基金supported by the Noncommunicable Chronic Diseases-National Science and Technology Major Project(2023ZD0506800).
文摘Children with autism often exhibit abnormalities in body weight,but the underlying mechanism remains unclear.SH3 and multiple ankyrin repeat domains protein 3(SHANK3),a scaffold protein of the postsynaptic density,has been reported to be associated with autism.This study aimed to investigate whether and how SHANK3 influences body weight in the hypothalamic neuronal regulation of energy homeostasis.Adeno-associated viruses 9(AAV9)carrying CMV-Cre and Agrp-Cre were stereotactically injected to restore SHANK3 expression in the arcuate nucleus(ARC)and agouti-related peptide(AgRP)neurons,respectively.Agrp-Cre mice were injected with AAV9-p38αflox/flox to overexpress p38α.Activated p38αwas generated by mutating both D176A and F327S in p38α.Inactivated p38αwas constructed by mutating both T180A and Y182F in p38α.Metabolic analysis,immunoblotting,histological analysis,the glucose tolerance test,the insulin tolerance test,and body fat mass analysis were applied to investigate the underlying mechanisms by which SHANK3 regulates body weight.We reveal that SHANK3 regulates body weight via the p38αsignaling pathway in the AgRP neurons of the hypothalamus.Shank3 knockout(Shank3−/−)mice exhibit resistance to diet-induced obesity.Shank3 re-expression in the ARC or AgRP neurons increases body weight in Shank3 knock-in mice with an inverted allele(SKO).Overexpression or activation of p38αin AgRP neurons elicits resistance to diet-induced obesity.Inactivated p38αin AgRP neurons abolished the resistance to diet-induced obesity due to SHANK3 deficiency.Our findings suggest that the SHANK3-p38αsiganling pathway in AgRP neurons regulates body weight balance in autism,revealing a promising therapeutic target for obesity in children with autism.
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,Nos. 82173806 and U1803281Chinese Academy of Medical Sciences (CAMS) Innovation Fund for Medical Science,Nos. 2021-I2M-1-030 and 2022-I2M-2-002Non-Profit Central Research Institute Fund of Chinese Academy of Medical Sciences,No. 2022-JKCS-08 (all to RL)。
文摘Long noncoding RNA and microRNA are regulatory noncoding RNAs that are implicated in Alzheimer's disease, but the role of long noncoding RNA-associated competitive endogenous RNA has not been fully elucidated. The long noncoding RNA growth arrest-specific 5(GAS5) is a member of the 5′-terminal oligopyrimidine gene family that may be involved in neurological disorders, but its role in Alzheimer's disease remains unclear. This study aimed to investigate the function of GAS5 and construct a GAS5-associated competitive endogenous RNA network comprising potential targets. RNA sequencing results showed that GAS5 was upregulated in five familial Alzheimer's disease(5×FAD) mice, APPswe/PSEN1dE9(APP/PS1) mice, Alzheimer's disease-related APPswe cells, and serum from patients with Alzheimer's disease. Functional experiments with targeted overexpression and silencing demonstrated that GAS5 played a role in cognitive dysfunction and multiple Alzheimer's disease-associated pathologies, including tau hyperphosphorylation, amyloid-beta accumulation, and neuronal apoptosis. Mechanistic studies indicated that GAS5 acted as an endogenous sponge by competing for microRNA-23b-3p(miR-23b-3p) binding to regulate its targets glycogen synthase kinase 3beta(GSK-3β) and phosphatase and tensin homologue deleted on chromosome 10(PTEN) expression in an Argonaute 2-induced RNA silencing complex(RISC)-dependent manner. GAS5 inhibited miR-23b-3p-mediated GSK-3β and PTEN cascades with a feedforward PTEN/protein kinase B(Akt)/GSK-3β linkage. Furthermore, recovery of GAS5/miR-23b-3p/GSK-3β/PTEN pathways relieved Alzheimer's disease-like symptoms in vivo, indicated by the amelioration of spatial cognition, neuronal degeneration, amyloid-beta load, and tau phosphorylation. Together, these findings suggest that GAS5 promotes Alzheimer's disease pathogenesis. This study establishes the functional convergence of the GAS5/miR-23b-3p/GSK-3β/PTEN pathway on multiple pathologies, suggesting a candidate therapeutic target in Alzheimer's disease.
