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Vicidomini R, Choudhury SD, Han TH, Nguyen TH, Nguyen P, Opazo F, Serpe M. Versatile nanobody-based approach to image, track and reconstitute functional Neurexin-1 in vivo. Nat Commun 2024; 15:6068. [PMID: 39025931 PMCID: PMC11258300 DOI: 10.1038/s41467-024-50462-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 07/10/2024] [Indexed: 07/20/2024] Open
Abstract
Neurexins are key adhesion proteins that coordinate extracellular and intracellular synaptic components. Nonetheless, the low abundance of these multidomain proteins has complicated any localization and structure-function studies. Here we combine an ALFA tag (AT)/nanobody (NbALFA) tool with classic genetics, cell biology and electrophysiology to examine the distribution and function of the Drosophila Nrx-1 in vivo. We generate full-length and ΔPDZ ALFA-tagged Nrx-1 variants and find that the PDZ binding motif is key to Nrx-1 surface expression. A PDZ binding motif provided in trans, via genetically encoded cytosolic NbALFA-PDZ chimera, fully restores the synaptic localization and function of NrxΔPDZ-AT. Using cytosolic NbALFA-mScarlet intrabody, we achieve compartment-specific detection of endogenous Nrx-1, track live Nrx-1 transport along the motor neuron axons, and demonstrate that Nrx-1 co-migrates with Rab2-positive vesicles. Our findings illustrate the versatility of the ALFA system and pave the way towards dissecting functional domains of complex proteins in vivo.
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Affiliation(s)
- Rosario Vicidomini
- Section on Cellular Communication, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Saumitra Dey Choudhury
- Section on Cellular Communication, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
- Centralized Core Research Facility-Microscopy, All India Institute of Medical Sciences, New Delhi, Delhi, India
| | - Tae Hee Han
- Section on Cellular Communication, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Tho Huu Nguyen
- Section on Cellular Communication, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Peter Nguyen
- Section on Cellular Communication, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Felipe Opazo
- Department of Neuro and Sensory Physiology, University Medical Center Göttingen, Göttingen, Germany
- NanoTag Biotechnologies GmbH, Göttingen, Germany
| | - Mihaela Serpe
- Section on Cellular Communication, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA.
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Bai SY, Zeng DY, Ouyang M, Zeng Y, Tan W, Xu L. Synaptic cell adhesion molecules contribute to the pathogenesis and progression of fragile X syndrome. Front Cell Neurosci 2024; 18:1393536. [PMID: 39022311 PMCID: PMC11252757 DOI: 10.3389/fncel.2024.1393536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 06/19/2024] [Indexed: 07/20/2024] Open
Abstract
Fragile X syndrome (FXS) is the most common form of inherited intellectual disability and a monogenic cause of autism spectrum disorders. Deficiencies in the fragile X messenger ribonucleoprotein, encoded by the FMR1 gene, lead to various anatomical and pathophysiological abnormalities and behavioral deficits, such as spine dysmorphogenesis and learning and memory impairments. Synaptic cell adhesion molecules (CAMs) play crucial roles in synapse formation and neural signal transmission by promoting the formation of new synaptic contacts, accurately organizing presynaptic and postsynaptic protein complexes, and ensuring the accuracy of signal transmission. Recent studies have implicated synaptic CAMs such as the immunoglobulin superfamily, N-cadherin, leucine-rich repeat proteins, and neuroligin-1 in the pathogenesis of FXS and found that they contribute to defects in dendritic spines and synaptic plasticity in FXS animal models. This review systematically summarizes the biological associations between nine representative synaptic CAMs and FMRP, as well as the functional consequences of the interaction, to provide new insights into the mechanisms of abnormal synaptic development in FXS.
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Affiliation(s)
- Shu-Yuan Bai
- Geriatric Hospital Affiliated to Wuhan University of Science and Technology, Wuhan, China
- Hubei Provincial Clinical Research Center for Alzheimer's Disease, Wuhan University of Science and Technology, Wuhan, China
| | - De-Yang Zeng
- Geriatric Hospital Affiliated to Wuhan University of Science and Technology, Wuhan, China
- Hubei Provincial Clinical Research Center for Alzheimer's Disease, Wuhan University of Science and Technology, Wuhan, China
| | - Ming Ouyang
- Geriatric Hospital Affiliated to Wuhan University of Science and Technology, Wuhan, China
- Hubei Provincial Clinical Research Center for Alzheimer's Disease, Wuhan University of Science and Technology, Wuhan, China
| | - Yan Zeng
- Geriatric Hospital Affiliated to Wuhan University of Science and Technology, Wuhan, China
- Hubei Provincial Clinical Research Center for Alzheimer's Disease, Wuhan University of Science and Technology, Wuhan, China
| | - Wei Tan
- Geriatric Hospital Affiliated to Wuhan University of Science and Technology, Wuhan, China
- Hubei Provincial Clinical Research Center for Alzheimer's Disease, Wuhan University of Science and Technology, Wuhan, China
| | - Lang Xu
- Geriatric Hospital Affiliated to Wuhan University of Science and Technology, Wuhan, China
- Hubei Provincial Clinical Research Center for Alzheimer's Disease, Wuhan University of Science and Technology, Wuhan, China
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3
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Melrose J. CNS/PNS proteoglycans functionalize neuronal and astrocyte niche microenvironments optimizing cellular activity by preserving membrane polarization dynamics, ionic microenvironments, ion fluxes, neuronal activation, and network neurotransductive capacity. J Neurosci Res 2024; 102:e25361. [PMID: 39034899 DOI: 10.1002/jnr.25361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 03/22/2024] [Accepted: 05/27/2024] [Indexed: 07/23/2024]
Abstract
Central and peripheral nervous system (CNS/PNS) proteoglycans (PGs) have diverse functional roles, this study examined how these control cellular behavior and tissue function. The CNS/PNS extracellular matrix (ECM) is a dynamic, responsive, highly interactive, space-filling, cell supportive, stabilizing structure maintaining tissue compartments, ionic microenvironments, and microgradients that regulate neuronal activity and maintain the neuron in an optimal ionic microenvironment. The CNS/PNS contains a high glycosaminoglycan content (60% hyaluronan, HA) and a diverse range of stabilizing PGs. Immobilization of HA in brain tissues by HA interactive hyalectan PGs preserves tissue hydration and neuronal activity, a paucity of HA in brain tissues results in a pro-convulsant epileptic phenotype. Diverse CS, KS, and HSPGs stabilize the blood-brain barrier and neurovascular unit, provide smart gel neurotransmitter neuron vesicle storage and delivery, organize the neuromuscular junction basement membrane, and provide motor neuron synaptic plasticity, and photoreceptor and neuron synaptic functions. PG-HA networks maintain ionic fluxes and microgradients and tissue compartments that contribute to membrane polarization dynamics essential to neuronal activation and neurotransduction. Hyalectans form neuroprotective perineuronal nets contributing to synaptic plasticity, memory, and cognitive learning. Sialoglycoprotein associated with cones and rods (SPACRCAN), an HA binding CSPG, stabilizes the inter-photoreceptor ECM. HSPGs pikachurin and eyes shut stabilize the photoreceptor synapse aiding in phototransduction and neurotransduction with retinal bipolar neurons crucial to visual acuity. This is achieved through Laminin G motifs in pikachurin, eyes shut, and neurexins that interact with the dystroglycan-cytoskeleton-ECM-stabilizing synaptic interconnections, neuronal interactive specificity, and co-ordination of regulatory action potentials in neural networks.
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Affiliation(s)
- James Melrose
- Raymond Purves Bone and Joint Research Laboratory, Kolling Institute, Northern Sydney Local Health District, St. Leonards, New South Wales, Australia
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
- Sydney Medical School, Northern, The University of Sydney Faculty of Medicine and Health, Royal North Shore Hospital, St. Leonards, New South Wales, Australia
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Gedman GL, Kimball TH, Atkinson LL, Factor D, Vojtova G, Farias-Virgens M, Wright TF, White SA. CHIRP-Seq: FoxP2 transcriptional targets in zebra finch brain include numerous speech and language-related genes. RESEARCH SQUARE 2024:rs.3.rs-4542378. [PMID: 38978588 PMCID: PMC11230500 DOI: 10.21203/rs.3.rs-4542378/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Background Vocal learning is a rare, convergent trait that is fundamental to both human speech and birdsong. The Forkhead Box P2 (FoxP2) transcription factor appears necessary for both types of learned signals, as human mutations in FoxP2 result in speech deficits, and disrupting its expression in zebra finches impairs male-specific song learning. In juvenile and adult male finches, striatal FoxP2 mRNA and protein decline acutely within song-dedicated neurons during singing, indicating that its transcriptional targets are also behaviorally regulated. The identities of these targets in songbirds, and whether they differ across sex, development and/or behavioral conditions, are largely unknown. Results Here we used chromatin immunoprecipitation followed by sequencing (ChIP-Seq) to identify genomic sites bound by FoxP2 in male and female, juvenile and adult, and singing and non-singing birds. Our results suggest robust FoxP2 binding concentrated in putative promoter regions of genes. The number of genes likely to be bound by FoxP2 varied across conditions, suggesting specialized roles of the candidate targets related to sex, age, and behavioral state. We validated these binding targets both bioinformatically, with comparisons to previous studies and biochemically, with immunohistochemistry using an antibody for a putative target gene. Gene ontology analyses revealed enrichment for human speech- and language-related functions in males only, consistent with the sexual dimorphism of song learning in this species. Fewer such targets were found in juveniles relative to adults, suggesting an expansion of this regulatory network with maturation. The fewest speech-related targets were found in the singing condition, consistent with the well-documented singing-driven down-regulation of FoxP2 in the songbird striatum. Conclusions Overall, these data provide an initial catalog of the regulatory landscape of FoxP2 in an avian vocal learner, offering dozens of target genes for future study and providing insight into the molecular underpinnings of vocal learning.
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Adeoye T, Shah SI, Ullah G. Systematic Analysis of Biological Processes Reveals Gene Co-expression Modules Driving Pathway Dysregulation in Alzheimer's Disease. Aging Dis 2024:AD.2024.0429. [PMID: 38913039 DOI: 10.14336/ad.2024.0429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Accepted: 06/12/2024] [Indexed: 06/25/2024] Open
Abstract
Alzheimer's disease (AD) manifests as a complex systems pathology with intricate interplay among various genes and biological processes. Traditional differential gene expression (DEG) analysis, while commonly employed to characterize AD-driven perturbations, does not sufficiently capture the full spectrum of underlying biological processes. Utilizing single-nucleus RNA-sequencing data from postmortem brain samples across key regions-middle temporal gyrus, superior frontal gyrus, and entorhinal cortex-we provide a comprehensive systematic analysis of disrupted processes in AD. We go beyond the DEG-centric analysis by integrating pathway activity analysis with weighted gene co-expression patterns to comprehensively map gene interconnectivity, identifying region- and cell-type-specific drivers of biological processes associated with AD. Our analysis reveals profound modular heterogeneity in neurons and glia as well as extensive AD-related functional disruptions. Co-expression networks highlighted the extended involvement of astrocytes and microglia in biological processes beyond neuroinflammation, such as calcium homeostasis, glutamate regulation, lipid metabolism, vesicle-mediated transport, and TOR signaling. We find limited representation of DEGs within dysregulated pathways across neurons and glial cells, suggesting that differential gene expression alone may not adequately represent the disease complexity. Further dissection of inferred gene modules revealed distinct dynamics of hub DEGs in neurons versus glia, suggesting that DEGs exert more impact on neurons compared to glial cells in driving modular dysregulations underlying perturbed biological processes. Interestingly, we observe an overall downregulation of astrocyte and microglia modules across all brain regions in AD, indicating a prevailing trend of functional repression in glial cells across these regions. Notable genes from the CALM and HSP90 families emerged as hub genes across neuronal modules in all brain regions, suggesting conserved roles as drivers of synaptic dysfunction in AD. Our findings demonstrate the importance of an integrated, systems-oriented approach combining pathway and network analysis to comprehensively understand the cell-type-specific roles of genes in AD-related biological processes.
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Leow KQ, Tonta MA, Lu J, Coleman HA, Parkington HC. Towards understanding sex differences in autism spectrum disorders. Brain Res 2024; 1833:148877. [PMID: 38513995 DOI: 10.1016/j.brainres.2024.148877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 03/17/2024] [Accepted: 03/18/2024] [Indexed: 03/23/2024]
Abstract
Autism Spectrum Disorder (ASD) is a neurodevelopmental condition characterized by social deficits, repetitive behaviours and lack of empathy. Its significant genetic heritability and potential comorbidities often lead to diagnostic and therapeutic challenges. This review addresses the biological basis of ASD, focusing on the sex differences in gene expression and hormonal influences. ASD is more commonly diagnosed in males at a ratio of 4:1, indicating a potential oversight in female-specific ASD research and a risk of underdiagnosis in females. We consider how ASD manifests differently across sexes by exploring differential gene expression in female and male brains and consider how variations in steroid hormones influence ASD characteristics. Synaptic function, including excitation/inhibition ratio imbalance, is influenced by gene mutations and this is explored as a key factor in the cognitive and behavioural manifestations of ASD. We also discuss the role of micro RNAs (miRNAs) and highlight a novel mutation in miRNA-873, which affects a suite of key synaptic genes, neurexin, neuroligin, SHANK and post-synaptic density proteins, implicated in the pathology of ASD. Our review suggests that genetic predisposition, sex differences in brain gene expression, and hormonal factors significantly contribute to the presentation, identification and severity of ASD, necessitating sex-specific considerations in diagnosis and treatments. These findings advocate for personalized interventions to improve the outcomes for individuals with ASD.
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Affiliation(s)
- Karen Q Leow
- Department of Physiology, Biomedical Discovery Institute, Monash University, Victoria, Australia
| | - Mary A Tonta
- Department of Physiology, Biomedical Discovery Institute, Monash University, Victoria, Australia
| | - Jing Lu
- Tianjin Institute of Infectious Disease, Second Hospital of Tianjin Medical University, China
| | - Harold A Coleman
- Department of Physiology, Biomedical Discovery Institute, Monash University, Victoria, Australia
| | - Helena C Parkington
- Department of Physiology, Biomedical Discovery Institute, Monash University, Victoria, Australia.
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Matúš D, Lopez JM, Sando RC, Südhof TC. Essential Role of Latrophilin-1 Adhesion GPCR Nanoclusters in Inhibitory Synapses. J Neurosci 2024; 44:e1978232024. [PMID: 38684366 PMCID: PMC11154861 DOI: 10.1523/jneurosci.1978-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 02/03/2024] [Accepted: 02/20/2024] [Indexed: 05/02/2024] Open
Abstract
Latrophilin-1 (Lphn1, aka CIRL1 and CL1; gene symbol Adgrl1) is an adhesion GPCR that has been implicated in excitatory synaptic transmission as a candidate receptor for α-latrotoxin. Here we analyzed conditional knock-in/knock-out mice for Lphn1 that contain an extracellular myc epitope tag. Mice of both sexes were used in all experiments. Surprisingly, we found that Lphn1 is localized in cultured neurons to synaptic nanoclusters that are present in both excitatory and inhibitory synapses. Conditional deletion of Lphn1 in cultured neurons failed to elicit a detectable impairment in excitatory synapses but produced a decrease in inhibitory synapse numbers and synaptic transmission that was most pronounced for synapses close to the neuronal soma. No changes in axonal or dendritic outgrowth or branching were observed. Our data indicate that Lphn1 is among the few postsynaptic adhesion molecules that are present in both excitatory and inhibitory synapses and that Lphn1 by itself is not essential for excitatory synaptic transmission but is required for some inhibitory synaptic connections.
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Affiliation(s)
- Daniel Matúš
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305
| | - Jaybree M Lopez
- Department of Pharmacology, Vanderbilt Brain Institute, Vanderbilt University, Nashville, Tennessee 37240
| | - Richard C Sando
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305
- Department of Pharmacology, Vanderbilt Brain Institute, Vanderbilt University, Nashville, Tennessee 37240
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305
- Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305
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Yu X, Kim E. Editorial Overview: Molecular neuroscience. Curr Opin Neurobiol 2024; 86:102873. [PMID: 38564830 DOI: 10.1016/j.conb.2024.102873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Affiliation(s)
- Xiang Yu
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University McGovern Institute, Peking University, Beijing 100871, China; Autism Research Center of Peking University Health Science Center, Beijing 100191, China; Chinese Institute for Brain Research, Beijing 102206, China.
| | - Eunjoon Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea; Center for Synaptic Brain Dysfunctions, Institute for Basic Science, Daejeon, 34141, South Korea.
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Jiang HH, Xu R, Nie X, Su Z, Xu X, Pang R, Zhou Y, Luo F. Neurexins control the strength and precise timing of glycinergic inhibition in the auditory brainstem. eLife 2024; 13:RP94315. [PMID: 38814174 PMCID: PMC11139475 DOI: 10.7554/elife.94315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024] Open
Abstract
Neurexins play diverse functions as presynaptic organizers in various glutamatergic and GABAergic synapses. However, it remains unknown whether and how neurexins are involved in shaping functional properties of the glycinergic synapses, which mediate prominent inhibition in the brainstem and spinal cord. To address these issues, we examined the role of neurexins in a model glycinergic synapse between the principal neuron in the medial nucleus of the trapezoid body (MNTB) and the principal neuron in the lateral superior olive (LSO) in the auditory brainstem. Combining RNAscope with stereotactic injection of AAV-Cre in the MNTB of neurexin1/2/3 conditional triple knockout mice, we showed that MNTB neurons highly express all isoforms of neurexins although their expression levels vary remarkably. Selective ablation of all neurexins in MNTB neurons not only reduced the amplitude but also altered the kinetics of the glycinergic synaptic transmission at LSO neurons. The synaptic dysfunctions primarily resulted from an impaired Ca2+ sensitivity of release and a loosened coupling between voltage-gated Ca2+ channels and synaptic vesicles. Together, our current findings demonstrate that neurexins are essential in controlling the strength and temporal precision of the glycinergic synapse, which therefore corroborates the role of neurexins as key presynaptic organizers in all major types of fast chemical synapses.
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Affiliation(s)
- He-Hai Jiang
- Guangzhou National LaboratoryGuangzhouChina
- Bioland LaboratoryGuangzhouChina
- School of Basic Medical Sciences, Guangzhou Medical UniversityGuangzhouChina
| | - Ruoxuan Xu
- Guangzhou National LaboratoryGuangzhouChina
| | | | | | | | - Ruiqi Pang
- Department of Neurobiology, School of Basic Medicine, Army Medical UniversityChongqingChina
- Advanced Institute for Brain and Intelligence, School of Medicine, Guangxi UniversityNanningChina
| | - Yi Zhou
- Department of Neurobiology, School of Basic Medicine, Army Medical UniversityChongqingChina
| | - Fujun Luo
- Guangzhou National LaboratoryGuangzhouChina
- School of Basic Medical Sciences, Guangzhou Medical UniversityGuangzhouChina
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Brocato ER, Easter R, Morgan A, Kakani M, Lee G, Wolstenholme JT. Adolescent binge ethanol impacts H3K9me3-occupancy at synaptic genes and the regulation of oligodendrocyte development. Front Mol Neurosci 2024; 17:1389100. [PMID: 38840776 PMCID: PMC11150558 DOI: 10.3389/fnmol.2024.1389100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 05/06/2024] [Indexed: 06/07/2024] Open
Abstract
Introduction Binge drinking in adolescence can disrupt myelination and cause brain structural changes that persist into adulthood. Alcohol consumption at a younger age increases the susceptibility of these changes. Animal models to understand ethanol's actions on myelin and white matter show that adolescent binge ethanol can alter the developmental trajectory of oligodendrocytes, myelin structure, and myelin fiber density. Oligodendrocyte differentiation is epigenetically regulated by H3K9 trimethylation (H3K9me3). Prior studies have shown that adolescent binge ethanol dysregulates H3K9 methylation and decreases H3K9-related gene expression in the PFC. Methods Here, we assessed ethanol-induced changes to H3K9me3 occupancy at genomic loci in the developing adolescent PFC. We further assessed ethanol-induced changes at the transcription level with qPCR time course approaches in oligodendrocyte-enriched cells to assess changes in oligodendrocyte progenitor and oligodendrocytes specifically. Results Adolescent binge ethanol altered H3K9me3 regulation of synaptic-related genes and genes specific for glutamate and potassium channels in a sex-specific manner. In PFC tissue, we found an early change in gene expression in transcription factors associated with oligodendrocyte differentiation that may lead to the later significant decrease in myelin-related gene expression. This effect appeared stronger in males. Conclusion Further exploration in oligodendrocyte cell enrichment time course and dose response studies could suggest lasting dysregulation of oligodendrocyte maturation at the transcriptional level. Overall, these studies suggest that binge ethanol may impede oligodendrocyte differentiation required for ongoing myelin development in the PFC by altering H3K9me3 occupancy at synaptic-related genes. We identify potential genes that may be contributing to adolescent binge ethanol-related myelin loss.
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Affiliation(s)
- Emily R. Brocato
- Pharmacology and Toxicology Department, Virginia Commonwealth University, Richmond, VA, United States
| | - Rachel Easter
- Alcohol Research Center, Virginia Commonwealth University, Richmond, VA, United States
| | - Alanna Morgan
- Alcohol Research Center, Virginia Commonwealth University, Richmond, VA, United States
| | - Meenakshi Kakani
- Pharmacology and Toxicology Department, Virginia Commonwealth University, Richmond, VA, United States
| | - Grace Lee
- Pharmacology and Toxicology Department, Virginia Commonwealth University, Richmond, VA, United States
| | - Jennifer T. Wolstenholme
- Pharmacology and Toxicology Department, Virginia Commonwealth University, Richmond, VA, United States
- Alcohol Research Center, Virginia Commonwealth University, Richmond, VA, United States
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Cesari E, Farini D, Medici V, Ehrmann I, Guerra M, Testa E, Naro C, Geloso MC, Pagliarini V, La Barbera L, D’Amelio M, Orsini T, Vecchioli SF, Tamagnone L, Fort P, Viscomi MT, Elliott DJ, Sette C. Differential expression of paralog RNA binding proteins establishes a dynamic splicing program required for normal cerebral cortex development. Nucleic Acids Res 2024; 52:4167-4184. [PMID: 38324473 PMCID: PMC11077083 DOI: 10.1093/nar/gkae071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 01/17/2024] [Accepted: 01/25/2024] [Indexed: 02/09/2024] Open
Abstract
Sam68 and SLM2 are paralog RNA binding proteins (RBPs) expressed in the cerebral cortex and display similar splicing activities. However, their relative functions during cortical development are unknown. We found that these RBPs exhibit an opposite expression pattern during development. Sam68 expression declines postnatally while SLM2 increases after birth, and this developmental pattern is reinforced by hierarchical control of Sam68 expression by SLM2. Analysis of Sam68:Slm2 double knockout (Sam68:Slm2dko) mice revealed hundreds of exons that respond to joint depletion of these proteins. Moreover, parallel analysis of single and double knockout cortices indicated that exons regulated mainly by SLM2 are characterized by a dynamic splicing pattern during development, whereas Sam68-dependent exons are spliced at relatively constant rates. Dynamic splicing of SLM2-sensitive exons is completely suppressed in the Sam68:Slm2dko developing cortex. Sam68:Slm2dko mice die perinatally with defects in neurogenesis and in neuronal differentiation, and develop a hydrocephalus, consistent with splicing alterations in genes related to these biological processes. Thus, our study reveals that developmental control of separate Sam68 and Slm2 paralog genes encoding homologous RBPs enables the orchestration of a dynamic splicing program needed for brain development and viability, while ensuring a robust redundant mechanism that supports proper cortical development.
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Affiliation(s)
- Eleonora Cesari
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
- Fondazione Policlinico Agostino Gemelli IRCCS, Largo Agostino Gemelli, 00168 Rome, Italy
| | - Donatella Farini
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
- Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143 Rome, Italy
| | - Vanessa Medici
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
| | - Ingrid Ehrmann
- Newcastle University Centre for Cancer, Newcastle University Institute of Biosciences, Newcastle NE1 3BZ, UK
| | - Marika Guerra
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
| | - Erika Testa
- Department of Life Science and Public Health, Section of Histology and Embryology, Catholic University of the Sacred Heart, Rome
| | - Chiara Naro
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
- Fondazione Policlinico Agostino Gemelli IRCCS, Largo Agostino Gemelli, 00168 Rome, Italy
| | - Maria Concetta Geloso
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
| | - Vittoria Pagliarini
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
- Fondazione Policlinico Agostino Gemelli IRCCS, Largo Agostino Gemelli, 00168 Rome, Italy
| | - Livia La Barbera
- Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143 Rome, Italy
| | - Marcello D’Amelio
- Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143 Rome, Italy
- Università Campus Bio-Medico di Roma, Via Álvaro del Portillo, 21, 00128 Rome, Italy
| | - Tiziana Orsini
- Institute of Biochemistry and Cell Biology, National Research Council (IBBC/CNR), Monterotondo, 00015 Rome, Italy
| | - Stefano Farioli Vecchioli
- Institute of Biochemistry and Cell Biology, National Research Council (IBBC/CNR), Monterotondo, 00015 Rome, Italy
| | - Luca Tamagnone
- Fondazione Policlinico Agostino Gemelli IRCCS, Largo Agostino Gemelli, 00168 Rome, Italy
- Department of Life Science and Public Health, Section of Histology and Embryology, Catholic University of the Sacred Heart, Rome
| | - Philippe Fort
- Centre de Recherche en Biologie Cellulaire de Montpellier, University of Montpellier, CNRS, 1919 Route de Mende, 34293 Montpellier Cedex 05, France
| | - Maria Teresa Viscomi
- Fondazione Policlinico Agostino Gemelli IRCCS, Largo Agostino Gemelli, 00168 Rome, Italy
- Department of Life Science and Public Health, Section of Histology and Embryology, Catholic University of the Sacred Heart, Rome
| | - David J Elliott
- Newcastle University Centre for Cancer, Newcastle University Institute of Biosciences, Newcastle NE1 3BZ, UK
| | - Claudio Sette
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
- Fondazione Policlinico Agostino Gemelli IRCCS, Largo Agostino Gemelli, 00168 Rome, Italy
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Verpoort B, de Wit J. Cell Adhesion Molecule Signaling at the Synapse: Beyond the Scaffold. Cold Spring Harb Perspect Biol 2024; 16:a041501. [PMID: 38316556 PMCID: PMC11065171 DOI: 10.1101/cshperspect.a041501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Synapses are specialized intercellular junctions connecting pre- and postsynaptic neurons into functional neural circuits. Synaptic cell adhesion molecules (CAMs) constitute key players in synapse development that engage in homo- or heterophilic interactions across the synaptic cleft. Decades of research have identified numerous synaptic CAMs, mapped their trans-synaptic interactions, and determined their role in orchestrating synaptic connectivity. However, surprisingly little is known about the molecular mechanisms that translate trans-synaptic adhesion into the assembly of pre- and postsynaptic compartments. Here, we provide an overview of the intracellular signaling pathways that are engaged by synaptic CAMs and highlight outstanding issues to be addressed in future work.
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Affiliation(s)
- Ben Verpoort
- VIB-KU Leuven Center for Brain and Disease Research, 3000 Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, 3000 Leuven, Belgium
| | - Joris de Wit
- VIB-KU Leuven Center for Brain and Disease Research, 3000 Leuven, Belgium
- KU Leuven, Department of Neurosciences, Leuven Brain Institute, 3000 Leuven, Belgium
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13
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Turrel O, Gao L, Sigrist SJ. Presynaptic regulators in memory formation. Learn Mem 2024; 31:a054013. [PMID: 38862173 PMCID: PMC11199941 DOI: 10.1101/lm.054013.124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Accepted: 04/17/2024] [Indexed: 06/13/2024]
Abstract
The intricate molecular and structural sequences guiding the formation and consolidation of memories within neuronal circuits remain largely elusive. In this study, we investigate the roles of two pivotal presynaptic regulators, the small GTPase Rab3, enriched at synaptic vesicles, and the cell adhesion protein Neurexin-1, in the formation of distinct memory phases within the Drosophila mushroom body Kenyon cells. Our findings suggest that both proteins play crucial roles in memory-supporting processes within the presynaptic terminal, operating within distinct plasticity modules. These modules likely encompass remodeling and maturation of existing active zones (AZs), as well as the formation of new AZs.
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Affiliation(s)
- Oriane Turrel
- Institute for Biology, Genetics, Freie Universität Berlin, 14195 Berlin, Germany
| | - Lili Gao
- Institute for Biology, Genetics, Freie Universität Berlin, 14195 Berlin, Germany
| | - Stephan J Sigrist
- Institute for Biology, Genetics, Freie Universität Berlin, 14195 Berlin, Germany
- Cluster of Excellence NeuroCure, Charité Universitätsmedizin Berlin, 10117 Berlin, Germany
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14
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Liu X, Wu L, Wang L, Li Y. Identification and classification of glioma subtypes based on RNA-binding proteins. Comput Biol Med 2024; 174:108404. [PMID: 38582000 DOI: 10.1016/j.compbiomed.2024.108404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 03/23/2024] [Accepted: 04/01/2024] [Indexed: 04/08/2024]
Abstract
BACKGROUND Glioma is a common and aggressive primary malignant cancer known for its high morbidity, mortality, and recurrence rates. Despite this, treatment options for glioma are currently restricted. The dysregulation of RBPs has been linked to the advancement of several types of cancer, but their precise role in glioma evolution is still not fully understood. This study sought to investigate how RBPs may impact the development and prognosis of glioma, with potential implications for prognosis and therapy. METHODS RNA-seq profiles of glioma and corresponding clinical data from the CGGA database were initially collected for analysis. Unsupervised clustering was utilized to identify crucial tumor subtypes in glioma development. Subsequent time-series analysis and MS model were employed to track the progression of these identified subtypes. RBPs playing a significant role in glioma progression were then pinpointed using WGCNA and Lasso Cox regression models. Functional analysis of these key RBP-related genes was conducted through GSEA. Additionally, the CIBERSORT algorithm was utilized to estimate immune infiltrating cells, while the STRING database was consulted to uncover potential mechanisms of the identified biomarkers. RESULTS Six tumor subgroups were identified and found to be highly homogeneous within each subgroup. The progression stages of these tumor subgroups were determined using time-series analysis and a MS model. Through WGCNA, Lasso Cox, and multivariate Cox regression analysis, it was confirmed that BCLAF1 is correlated with survival in glioma patients and is closely linked to glioma progression. Functional annotation suggests that BCLAF1 may impact glioma progression by influencing RNA splicing, which in turn affects the cell cycle, Wnt signaling pathway, and other cancer development pathways. CONCLUSIONS The study initially identified six subtypes of glioma progression and assessed their malignancy ranking. Furthermore, it was determined that BCLAF1 could serve as an RBP-related prognostic marker, offering significant implications for the clinical diagnosis and personalized treatment of glioma.
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Affiliation(s)
- Xudong Liu
- School of Medicine, Chongqing University, Chongqing, 400044, China; Department of Medical Oncology, Chongqing University Cancer Hospital, Chongqing, 400030, China
| | - Lei Wu
- Department of Medical Oncology, Chongqing University Cancer Hospital, Chongqing, 400030, China
| | - Lei Wang
- College of Life Sciences, Xinyang Normal University, Xinyang, 464000, China.
| | - Yongsheng Li
- Department of Medical Oncology, Chongqing University Cancer Hospital, Chongqing, 400030, China.
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15
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Ruan Y, Yuan R, He J, Jiang Y, Chu S, Chen N. New perspective on sustained antidepressant effect: focus on neurexins regulating synaptic plasticity. Cell Death Discov 2024; 10:205. [PMID: 38693106 PMCID: PMC11063156 DOI: 10.1038/s41420-024-01974-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Revised: 04/17/2024] [Accepted: 04/17/2024] [Indexed: 05/03/2024] Open
Abstract
Depression is highly prevalent globally, however, currently available medications face challenges such as low response rates and short duration of efficacy. Additionally, depression mostly accompany other psychiatric disorders, further progressing to major depressive disorder without long-term effective management. Thus, sustained antidepressant strategies are urgently needed. Recently, ketamine and psilocybin gained attention as potential sustained antidepressants. Review of recent studies highlights that synaptic plasticity changes as key events of downstream long-lasting changes in sustained antidepressant effect. This underscores the significance of synaptic plasticity in sustained antidepressant effect. Moreover, neurexins, key molecules involved in the regulation of synaptic plasticity, act as critical links between synaptic plasticity and sustained antidepressant effects, involving mechanisms including protein level, selective splicing, epigenetics, astrocytes, positional redistribution and protein structure. Based on the regulation of synaptic plasticity by neurexins, several drugs with potential for sustained antidepressant effect are also discussed. Focusing on neurexins in regulating synaptic plasticity promises much for further understanding underlying mechanisms of sustained antidepressant and the next step in new drug development. This research represents a highly promising future research direction.
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Affiliation(s)
- Yuan Ruan
- Tianjin University of Traditional Chinese Medicine, Tianjin, PR China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China
| | - Ruolan Yuan
- Tianjin University of Traditional Chinese Medicine, Tianjin, PR China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China
| | - Jiaqi He
- Tianjin University of Traditional Chinese Medicine, Tianjin, PR China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China
| | - Yutong Jiang
- Tianjin University of Traditional Chinese Medicine, Tianjin, PR China
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China
| | - Shifeng Chu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
| | - Naihong Chen
- Tianjin University of Traditional Chinese Medicine, Tianjin, PR China.
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
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16
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Sun Z, Wang H, Xu Y, Liu Y, Wang L, Zhou R, Zhou R, Ma W, Zhang T. High expression of NXPH4 correlates with poor prognosis, metabolic reprogramming, and immune infiltration in colon adenocarcinoma. J Gastrointest Oncol 2024; 15:641-667. [PMID: 38756632 PMCID: PMC11094489 DOI: 10.21037/jgo-23-956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 03/15/2024] [Indexed: 05/18/2024] Open
Abstract
Background Colon adenocarcinoma (COAD) is a prevalent gastrointestinal malignant disease with high mortality rate, and identification of novel prognostic biomarkers and therapeutic targets is urgently needed. Although neurexophilin 4 (NXPH4) has been investigated in several tumors, its role in COAD remains unclear. The aim of this study was to explore the prognostic value and potential functions of NXPH4 in COAD. Methods The expression of NXPH4 in COAD were analyzed using The Cancer Genome Atlas (TCGA) and datasets from the Gene Expression Omnibus (GEO) database. The prognostic value of NXPH4 was determined using Kaplan-Meier analysis and Cox regression analysis. To investigate the possible mechanism underlying the role of NXPH4 in COAD, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene set enrichment analysis (GSEA) were employed. The correlation between NXPH4 expression and immune cell infiltration levels was examined thorough single-sample gene set enrichment analysis (ssGSEA). Furthermore, the competing endogenous RNA (ceRNA) regulatory network that may be involved in NXPH4 in COAD was predicted and constructed through a variety of databases. Results NXPH4 expression was significantly higher in COAD tissue compared with normal colon tissues. Meanwhile, high expression of NXPH4 was associated with poor prognosis in COAD patients. GO-KEGG and GSEA analyses indicated that NXPH4 was associated with glycolysis and hypoxia pathway, and may promote COAD progression and metastasis by modulating metabolic reprogramming. ssGSEA analysis demonstrated that NXPH4 expression also associated with immune infiltration. Furthermore, we identified various microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) as upstream regulators of NXPH4 in COAD. Conclusions The present study revealed that high expression of NXPH4 is associated with tumor progression, metabolic reprogramming, and immune infiltration. These findings suggest that NXPH4 could serve as a reliable prognostic biomarker and a promising therapeutic target in COAD.
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Affiliation(s)
- Zhe Sun
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Haodi Wang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Yao Xu
- Institute of Biology and Medicine, College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan, China
| | - Yichi Liu
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Lu Wang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Ruijie Zhou
- Institute of Biology and Medicine, College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan, China
| | - Runlong Zhou
- Institute of Biology and Medicine, College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan, China
| | - Wenjian Ma
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
- Qilu Institute of Technology, Jinan, China
| | - Tongcun Zhang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
- Institute of Biology and Medicine, College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan, China
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17
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Iwanaga R, Yahagi N, Hakeda-Suzuki S, Suzuki T. Cell adhesion and actin dynamics factors promote axonal extension and synapse formation in transplanted Drosophila photoreceptor cells. Dev Growth Differ 2024; 66:205-218. [PMID: 38403285 DOI: 10.1111/dgd.12916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 02/27/2024]
Abstract
Vision is formed by the transmission of light stimuli to the brain through axons extending from photoreceptor cells. Damage to these axons leads to loss of vision. Despite research on neural circuit regeneration through transplantation, achieving precise axon projection remains challenging. To achieve optic nerve regeneration by transplantation, we employed the Drosophila visual system. We previously established a transplantation method for Drosophila utilizing photoreceptor precursor cells extracted from the eye disc. However, little axonal elongation of transplanted cells into the brain, the lamina, was observed. We verified axonal elongation to the lamina by modifying the selection process for transplanted cells. Moreover, we focused on N-cadherin (Ncad), a cell adhesion factor, and Twinstar (Tsr), which has been shown to promote actin reorganization and induce axon elongation in damaged nerves. Overexpression of Ncad and tsr promoted axon elongation to the lamina, along with presynaptic structure formation in the elongating axons. Furthermore, overexpression of Neurexin-1 (Nrx-1), encoding a protein identified as a synaptic organizer, was found to not only promote presynapse formation but also enhance axon elongation. By introducing Ncad, tsr, and Nrx-1, we not only successfully achieved axonal projection of transplanted cells to the brain beyond the retina, but also confirmed the projection of transplanted cells into a deeper ganglion, the medulla. The present study offers valuable insights to realize regeneration through transplantation in a more complex nervous system.
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Affiliation(s)
- Riku Iwanaga
- School of Life Science and Technology, Tokyo Institute of Technology, Yokahama, Japan
| | - Nagisa Yahagi
- School of Life Science and Technology, Tokyo Institute of Technology, Yokahama, Japan
| | - Satoko Hakeda-Suzuki
- School of Life Science and Technology, Tokyo Institute of Technology, Yokahama, Japan
- Research Initiatives and Promotion Organization, Yokohama National University, Yokohama, Japan
| | - Takashi Suzuki
- School of Life Science and Technology, Tokyo Institute of Technology, Yokahama, Japan
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18
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Adeoye T, Shah SI, Ullah G. Systematic Analysis of Biological Processes Reveals Gene Co-expression Modules Driving Pathway Dysregulation in Alzheimer's Disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.15.585267. [PMID: 38559218 PMCID: PMC10980062 DOI: 10.1101/2024.03.15.585267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Alzheimer's disease (AD) manifests as a complex systems pathology with intricate interplay among various genes and biological processes. Traditional differential gene expression (DEG) analysis, while commonly employed to characterize AD-driven perturbations, does not sufficiently capture the full spectrum of underlying biological processes. Utilizing single-nucleus RNA-sequencing data from postmortem brain samples across key regions-middle temporal gyrus, superior frontal gyrus, and entorhinal cortex-we provide a comprehensive systematic analysis of disrupted processes in AD. We go beyond the DEG-centric analysis by integrating pathway activity analysis with weighted gene co-expression patterns to comprehensively map gene interconnectivity, identifying region- and cell-type-specific drivers of biological processes associated with AD. Our analysis reveals profound modular heterogeneity in neurons and glia as well as extensive AD-related functional disruptions. Co-expression networks highlighted the extended involvement of astrocytes and microglia in biological processes beyond neuroinflammation, such as calcium homeostasis, glutamate regulation, lipid metabolism, vesicle-mediated transport, and TOR signaling. We find limited representation of DEGs within dysregulated pathways across neurons and glial cells, indicating that differential gene expression alone may not adequately represent the disease complexity. Further dissection of inferred gene modules revealed distinct dynamics of hub DEGs in neurons versus glia, highlighting the differential impact of DEGs on neurons compared to glial cells in driving modular dysregulations underlying perturbed biological processes. Interestingly, we note an overall downregulation of both astrocyte and microglia modules in AD across all brain regions, suggesting a prevailing trend of functional repression in glial cells across these regions. Notable genes, including those of the CALM and HSP90 family genes emerged as hub genes across neuronal modules in all brain regions, indicating conserved roles as drivers of synaptic dysfunction in AD. Our findings demonstrate the importance of an integrated, systems-oriented approach combining pathway and network analysis for a comprehensive understanding of the cell-type-specific roles of genes in AD-related biological processes.
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Affiliation(s)
- Temitope Adeoye
- Department of Physics, University of South Florida, Tampa, FL 33620
| | - Syed I Shah
- Department of Physics, University of South Florida, Tampa, FL 33620
| | - Ghanim Ullah
- Department of Physics, University of South Florida, Tampa, FL 33620
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19
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Di Liegro CM, Schiera G, Schirò G, Di Liegro I. Role of Post-Transcriptional Regulation in Learning and Memory in Mammals. Genes (Basel) 2024; 15:337. [PMID: 38540396 PMCID: PMC10970538 DOI: 10.3390/genes15030337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 02/27/2024] [Accepted: 03/01/2024] [Indexed: 06/14/2024] Open
Abstract
After many decades, during which most molecular studies on the regulation of gene expression focused on transcriptional events, it was realized that post-transcriptional control was equally important in order to determine where and when specific proteins were to be synthesized. Translational regulation is of the most importance in the brain, where all the steps of mRNA maturation, transport to different regions of the cells and actual expression, in response to specific signals, constitute the molecular basis for neuronal plasticity and, as a consequence, for structural stabilization/modification of synapses; notably, these latter events are fundamental for the highest brain functions, such as learning and memory, and are characterized by long-term potentiation (LTP) of specific synapses. Here, we will discuss the molecular bases of these fundamental events by considering both the role of RNA-binding proteins (RBPs) and the effects of non-coding RNAs involved in controlling splicing, editing, stability and translation of mRNAs. Importantly, it has also been found that dysregulation of mRNA metabolism/localization is involved in many pathological conditions, arising either during brain development or in the adult nervous system.
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Affiliation(s)
- Carlo Maria Di Liegro
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, 90128 Palermo, Italy; (C.M.D.L.); (G.S.)
| | - Gabriella Schiera
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, 90128 Palermo, Italy; (C.M.D.L.); (G.S.)
| | - Giuseppe Schirò
- Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, 90127 Palermo, Italy;
- Neurology and Multiple Sclerosis Center, Unità Operativa Complessa (UOC), Foundation Institute “G. Giglio”, 90015 Cefalù, Italy
| | - Italia Di Liegro
- Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, 90127 Palermo, Italy;
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20
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Melrose J. Hippo cell signaling and HS-proteoglycans regulate tissue form and function, age-dependent maturation, extracellular matrix remodeling, and repair. Am J Physiol Cell Physiol 2024; 326:C810-C828. [PMID: 38223931 DOI: 10.1152/ajpcell.00683.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 01/09/2024] [Accepted: 01/09/2024] [Indexed: 01/16/2024]
Abstract
This review examined how Hippo cell signaling and heparan sulfate (HS)-proteoglycans (HSPGs) regulate tissue form and function. Despite being a nonweight-bearing tissue, the brain is regulated by Hippo mechanoresponsive cell signaling pathways during embryonic development. HS-proteoglycans interact with growth factors, morphogens, and extracellular matrix components to regulate development and pathology. Pikachurin and Eyes shut (Eys) interact with dystroglycan to stabilize the photoreceptor axoneme primary cilium and ribbon synapse facilitating phototransduction and neurotransduction with bipolar retinal neuronal networks in ocular vision, the primary human sense. Another HSPG, Neurexin interacts with structural and adaptor proteins to stabilize synapses and ensure specificity of neural interactions, and aids in synaptic potentiation and plasticity in neurotransduction. HSPGs also stabilize the blood-brain barrier and motor neuron basal structures in the neuromuscular junction. Agrin and perlecan localize acetylcholinesterase and its receptors in the neuromuscular junction essential for neuromuscular control. The primary cilium is a mechanosensory hub on neurons, utilized by YES associated protein (YAP)-transcriptional coactivator with PDZ-binding motif (TAZ) Hippo, Hh, Wnt, transforming growth factor (TGF)-β/bone matrix protein (BMP) receptor tyrosine kinase cell signaling. Members of the glypican HSPG proteoglycan family interact with Smoothened and Patched G-protein coupled receptors on the cilium to regulate Hh and Wnt signaling during neuronal development. Control of glycosyl sulfotransferases and endogenous protease expression by Hippo TAZ YAP represents a mechanism whereby the fine structure of HS-proteoglycans can be potentially modulated spatiotemporally to regulate tissue morphogenesis in a similar manner to how Hippo signaling controls sialyltransferase expression and mediation of cell-cell recognition, dysfunctional sialic acid expression is a feature of many tumors.
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Affiliation(s)
- James Melrose
- Raymond Purves Laboratory, Institute of Bone and Joint Research, Kolling Institute of Medical Research, University of Sydney, Northern Sydney Local Health District, Royal North Shore Hospital, St. Leonards, New South Wales, Australia
- Sydney Medical School-Northern, University of Sydney at Royal North Shore Hospital, St. Leonards, New South Wales, Australia
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia
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21
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Han KA, Yoon TH, Kim J, Lee J, Lee JY, Jang G, Um JW, Kim JK, Ko J. Specification of neural circuit architecture shaped by context-dependent patterned LAR-RPTP microexons. Nat Commun 2024; 15:1624. [PMID: 38388459 PMCID: PMC10883964 DOI: 10.1038/s41467-024-45695-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 01/30/2024] [Indexed: 02/24/2024] Open
Abstract
LAR-RPTPs are evolutionarily conserved presynaptic cell-adhesion molecules that orchestrate multifarious synaptic adhesion pathways. Extensive alternative splicing of LAR-RPTP mRNAs may produce innumerable LAR-RPTP isoforms that act as regulatory "codes" for determining the identity and strength of specific synapse signaling. However, no direct evidence for this hypothesis exists. Here, using targeted RNA sequencing, we detected LAR-RPTP mRNAs in diverse cell types across adult male mouse brain areas. We found pronounced cell-type-specific patterns of two microexons, meA and meB, in Ptprd mRNAs. Moreover, diverse neural circuits targeting the same neuronal populations were dictated by the expression of different Ptprd variants with distinct inclusion patterns of microexons. Furthermore, conditional ablation of Ptprd meA+ variants at presynaptic loci of distinct hippocampal circuits impaired distinct modes of synaptic transmission and objection-location memory. Activity-triggered alterations of the presynaptic Ptprd meA code in subicular neurons mediates NMDA receptor-mediated postsynaptic responses in CA1 neurons and objection-location memory. Our data provide the evidence of cell-type- and/or circuit-specific expression patterns in vivo and physiological functions of LAR-RPTP microexons that are dynamically regulated.
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Affiliation(s)
- Kyung Ah Han
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea
- Center for Synapse Diversity and Specificity, DGIST, Daegu, 42988, Korea
| | - Taek-Han Yoon
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea
| | - Jinhu Kim
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea
| | - Jusung Lee
- Department of New Biology, DGIST, Daegu, 42988, Korea
| | - Ju Yeon Lee
- Korea Basic Science Institute, Research Center for Bioconvergence Analysis, Cheongju, 28119, Korea
| | - Gyubin Jang
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea
- Center for Synapse Diversity and Specificity, DGIST, Daegu, 42988, Korea
| | - Ji Won Um
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea
- Center for Synapse Diversity and Specificity, DGIST, Daegu, 42988, Korea
| | - Jong Kyoung Kim
- Department of New Biology, DGIST, Daegu, 42988, Korea
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Korea
| | - Jaewon Ko
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Korea.
- Center for Synapse Diversity and Specificity, DGIST, Daegu, 42988, Korea.
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22
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Koumoundourou A, Rannap M, De Bruyckere E, Nestel S, Reissner C, Egorov AV, Liu P, Missler M, Heimrich B, Draguhn A, Britsch S. Regulation of hippocampal mossy fiber-CA3 synapse function by a Bcl11b/C1ql2/Nrxn3(25b+) pathway. eLife 2024; 12:RP89854. [PMID: 38358390 PMCID: PMC10942602 DOI: 10.7554/elife.89854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024] Open
Abstract
The transcription factor Bcl11b has been linked to neurodevelopmental and neuropsychiatric disorders associated with synaptic dysfunction. Bcl11b is highly expressed in dentate gyrus granule neurons and is required for the structural and functional integrity of mossy fiber-CA3 synapses. The underlying molecular mechanisms, however, remained unclear. We show in mice that the synaptic organizer molecule C1ql2 is a direct functional target of Bcl11b that regulates synaptic vesicle recruitment and long-term potentiation at mossy fiber-CA3 synapses in vivo and in vitro. Furthermore, we demonstrate C1ql2 to exert its functions through direct interaction with a specific splice variant of neurexin-3, Nrxn3(25b+). Interruption of C1ql2-Nrxn3(25b+) interaction by expression of a non-binding C1ql2 mutant or by deletion of Nrxn3 in the dentate gyrus granule neurons recapitulates major parts of the Bcl11b as well as C1ql2 mutant phenotype. Together, this study identifies a novel C1ql2-Nrxn3(25b+)-dependent signaling pathway through which Bcl11b controls mossy fiber-CA3 synapse function. Thus, our findings contribute to the mechanistic understanding of neurodevelopmental disorders accompanied by synaptic dysfunction.
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Affiliation(s)
| | - Märt Rannap
- Institute of Physiology and Pathophysiology, Faculty of Medicine, Heidelberg UniversityHeidelbergGermany
| | | | - Sigrun Nestel
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of FreiburgFreiburgGermany
| | - Carsten Reissner
- Institute of Anatomy and Molecular Neurobiology, University of MünsterMünsterGermany
| | - Alexei V Egorov
- Institute of Physiology and Pathophysiology, Faculty of Medicine, Heidelberg UniversityHeidelbergGermany
| | - Pengtao Liu
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong KongHong KongChina
- Centre for Translational Stem Cell BiologyHong KongChina
| | - Markus Missler
- Institute of Anatomy and Molecular Neurobiology, University of MünsterMünsterGermany
| | - Bernd Heimrich
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of FreiburgFreiburgGermany
| | - Andreas Draguhn
- Institute of Physiology and Pathophysiology, Faculty of Medicine, Heidelberg UniversityHeidelbergGermany
| | - Stefan Britsch
- Institute of Molecular and Cellular Anatomy, Ulm UniversityUlmGermany
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23
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Correa E, Mialon M, Cizeron M, Bessereau JL, Pinan-Lucarre B, Kratsios P. UNC-30/PITX coordinates neurotransmitter identity with postsynaptic GABA receptor clustering. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.14.580278. [PMID: 38405977 PMCID: PMC10888783 DOI: 10.1101/2024.02.14.580278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Terminal selectors are transcription factors that control neuronal identity by regulating the expression of key effector molecules, such as neurotransmitter (NT) biosynthesis proteins, ion channels and neuropeptides. Whether and how terminal selectors control neuronal connectivity is poorly understood. Here, we report that UNC-30 (PITX2/3), the terminal selector of GABA motor neuron identity in C. elegans , is required for NT receptor clustering, a hallmark of postsynaptic differentiation. Animals lacking unc-30 or madd-4B, the short isoform of the MN-secreted synapse organizer madd-4 ( Punctin/ADAMTSL ), display severe GABA receptor type A (GABA A R) clustering defects in postsynaptic muscle cells. Mechanistically, UNC-30 acts directly to induce and maintain transcription of madd-4B and GABA biosynthesis genes (e.g., unc-25/GAD , unc-47/VGAT ). Hence, UNC-30 controls GABA A R clustering on postsynaptic muscle cells and GABA biosynthesis in presynaptic cells, transcriptionally coordinating two critical processes for GABA neurotransmission. Further, we uncover multiple target genes and a dual role for UNC-30 both as an activator and repressor of gene transcription. Our findings on UNC-30 function may contribute to our molecular understanding of human conditions, such as Axenfeld-Rieger syndrome, caused by PITX2 and PITX3 gene mutations.
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Shan D, Song Y, Zhang Y, Ho CW, Xia W, Li Z, Ge F, Ou Q, Dai Z, Dai Z. Neurexin dysfunction in neurodevelopmental and neuropsychiatric disorders: a PRIMSA-based systematic review through iPSC and animal models. Front Behav Neurosci 2024; 18:1297374. [PMID: 38380150 PMCID: PMC10876810 DOI: 10.3389/fnbeh.2024.1297374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 01/17/2024] [Indexed: 02/22/2024] Open
Abstract
Background Neurexins, essential synaptic proteins, are linked to neurodevelopmental and neuropsychiatric disorders like autism spectrum disorder (ASD) and schizophrenia. Objective Through this systematic review, we aimed to shed light on the relationship between neurexin dysfunction and its implications in neurodevelopmental and neuropsychiatric manifestations. Both animal and human-induced pluripotent stem cell (hiPSC) models served as our primary investigative platforms. Methods Utilizing the PRISMA 2020 guidelines, our search strategy involved scouring articles from the PubMed and Google Scholar databases covering a span of two decades (2003-2023). Of the initial collection, 27 rigorously evaluated studies formed the essence of our review. Results Our review suggested the significant ties between neurexin anomalies and neurodevelopmental and neuropsychiatric outcomes, most notably ASD. Rodent-based investigations delineated pronounced ASD-associated behaviors, and hiPSC models derived from ASD-diagnosed patients revealed the disruptions in calcium dynamics and synaptic activities. Additionally, our review underlined the integral role of specific neurexin variants, primarily NRXN1, in the pathology of schizophrenia. It was also evident from our observation that neurexin malfunctions were implicated in a broader array of these disorders, including ADHD, intellectual challenges, and seizure disorders. Conclusion This review accentuates the cardinal role neurexins play in the pathological process of neurodevelopmental and neuropsychiatric disorders. The findings underscore a critical need for standardized methodologies in developing animal and hiPSC models for future studies, aiming to minimize heterogeneity. Moreover, we highlight the need to expand research into less studied neurexin variants (i.e., NRXN2 and NRXN3), broadening the scope of our understanding in this field. Our observation also projects hiPSC models as potent tools for bridging research gaps, promoting translational research, and fostering the development of patient-specific therapeutic interventions.
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Affiliation(s)
- Dan Shan
- Department of Biobehavioral Sciences, Columbia University, New York, NY, United States
- Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom
| | - Yuming Song
- School of Medical Imaging, Hebei Medical University, Shijiazhuang, China
| | - Yanyi Zhang
- School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Cheong Wong Ho
- School of Medicine, University of Galway, Galway, Ireland
| | - Wenxin Xia
- School of Medicine, University of Galway, Galway, Ireland
| | - Zhi Li
- College of Health, Medicine and Wellbeing, University of Newcastle, Newcastle, NSW, Australia
| | - Fenfen Ge
- Faculty of Medicine, University of Iceland, Reykjavík, Iceland
| | - Qifeng Ou
- School of Medicine, University of Galway, Galway, Ireland
| | - Zijie Dai
- Division of Biosciences, Faculty of Life Sciences, University College London, London, United Kingdom
| | - Zhihao Dai
- School of Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
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25
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Wolterhoff N, Hiesinger PR. Synaptic promiscuity in brain development. Curr Biol 2024; 34:R102-R116. [PMID: 38320473 PMCID: PMC10849093 DOI: 10.1016/j.cub.2023.12.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
Precise synaptic connectivity is a prerequisite for the function of neural circuits, yet individual neurons, taken out of their developmental context, readily form unspecific synapses. How does the genome encode brain wiring in light of this apparent contradiction? Synaptic specificity is the outcome of a long series of developmental processes and mechanisms before, during and after synapse formation. How much promiscuity is permissible or necessary at the moment of synaptic partner choice depends on the extent to which prior development restricts available partners or subsequent development corrects initially made synapses. Synaptic promiscuity at the moment of choice can thereby play important roles in the development of precise connectivity, but also facilitate developmental flexibility and robustness. In this review, we assess the experimental evidence for the prevalence and roles of promiscuous synapse formation during brain development. Many well-established experimental approaches are based on developmental genetic perturbation and an assessment of synaptic connectivity only in the adult; this can make it difficult to pinpoint when a given defect or mechanism occurred. In many cases, such studies reveal mechanisms that restrict partner availability already prior to synapse formation. Subsequently, at the moment of choice, factors including synaptic competency, interaction dynamics and molecular recognition further restrict synaptic partners. The discussion of the development of synaptic specificity through the lens of synaptic promiscuity suggests an algorithmic process based on neurons capable of promiscuous synapse formation that are continuously prevented from making the wrong choices, with no single mechanism or developmental time point sufficient to explain the outcome.
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Affiliation(s)
- Neele Wolterhoff
- Division of Neurobiology, Free University Berlin, 14195 Berlin, Germany
| | - P Robin Hiesinger
- Division of Neurobiology, Free University Berlin, 14195 Berlin, Germany.
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26
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Gobom J, Brinkmalm A, Brinkmalm G, Blennow K, Zetterberg H. Alzheimer's Disease Biomarker Analysis Using Targeted Mass Spectrometry. Mol Cell Proteomics 2024; 23:100721. [PMID: 38246483 PMCID: PMC10926085 DOI: 10.1016/j.mcpro.2024.100721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 12/30/2023] [Accepted: 01/04/2024] [Indexed: 01/23/2024] Open
Abstract
Alzheimer's disease (AD) is characterized by several neuropathological changes, mainly extracellular amyloid aggregates (plaques), intraneuronal inclusions of phosphorylated tau (tangles), as well as neuronal and synaptic degeneration, accompanied by tissue reactions to these processes (astrocytosis and microglial activation) that precede neuronal network disturbances in the symptomatic phase of the disease. A number of biomarkers for these brain tissue changes have been developed, mainly using immunoassays. In this review, we discuss how targeted mass spectrometry (TMS) can be used to validate and further characterize classes of biomarkers reflecting different AD pathologies, such as tau- and amyloid-beta pathologies, synaptic dysfunction, lysosomal dysregulation, and axonal damage, and the prospect of using TMS to measure these proteins in clinical research and diagnosis. TMS advantages and disadvantages in relation to immunoassays are discussed, and complementary aspects of the technologies are discussed.
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Affiliation(s)
- Johan Gobom
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden.
| | - Ann Brinkmalm
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Gunnar Brinkmalm
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden; Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden; Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK; UK Dementia Research Institute at UCL, London, UK; Hong Kong Center for Neurodegenerative Diseases, Clear Water Bay, Hong Kong, China; Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, USA.
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27
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Mohrmann L, Seebach J, Missler M, Rohlmann A. Distinct Alterations in Dendritic Spine Morphology in the Absence of β-Neurexins. Int J Mol Sci 2024; 25:1285. [PMID: 38279285 PMCID: PMC10817056 DOI: 10.3390/ijms25021285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/12/2024] [Accepted: 01/18/2024] [Indexed: 01/28/2024] Open
Abstract
Dendritic spines are essential for synaptic function because they constitute the postsynaptic compartment of the neurons that receives the most excitatory input. The extracellularly shorter variant of the presynaptic cell adhesion molecules neurexins, β-neurexin, has been implicated in various aspects of synaptic function, including neurotransmitter release. However, its role in developing or stabilizing dendritic spines as fundamental computational units of excitatory synapses has remained unclear. Here, we show through morphological analysis that the deletion of β-neurexins in hippocampal neurons in vitro and in hippocampal tissue in vivo affects presynaptic dense-core vesicles, as hypothesized earlier, and, unexpectedly, alters the postsynaptic spine structure. Specifically, we observed that the absence of β-neurexins led to an increase in filopodial-like protrusions in vitro and more mature mushroom-type spines in the CA1 region of adult knockout mice. In addition, the deletion of β-neurexins caused alterations in the spine head dimension and an increase in spines with perforations of their postsynaptic density but no changes in the overall number of spines or synapses. Our results indicate that presynaptic β-neurexins play a role across the synaptic cleft, possibly by aligning with postsynaptic binding partners and glutamate receptors via transsynaptic columns.
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Affiliation(s)
| | | | - Markus Missler
- Institute of Anatomy and Molecular Neurobiology, University Münster, 48149 Münster, Germany; (L.M.); (J.S.)
| | - Astrid Rohlmann
- Institute of Anatomy and Molecular Neurobiology, University Münster, 48149 Münster, Germany; (L.M.); (J.S.)
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28
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Dabrowski KR, Floris G, Gillespie A, Daws SE. Orbitofrontal intronic circular RNA from Nrxn3 mediates reward learning and motivation for reward. Prog Neurobiol 2024; 232:102546. [PMID: 38036039 PMCID: PMC10843848 DOI: 10.1016/j.pneurobio.2023.102546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 10/27/2023] [Accepted: 11/20/2023] [Indexed: 12/02/2023]
Abstract
The orbitofrontal cortex (OFC) is a vital component of brain reward circuitry that is important for reward seeking behavior. However, OFC-mediated molecular mechanisms underlying rewarding behavior are understudied. Here, we report the first circular RNA (circRNA) profile associated with appetitive reward and identify regulation of 92 OFC circRNAs by sucrose self-administration. Among these changes, we observed downregulation of circNrxn3, a circRNA originating from neurexin 3 (Nrxn3), a gene involved in synaptogenesis, learning, and memory. Transcriptomic profiling via RNA sequencing and qPCR of the OFC following in vivo knock-down of circNrxn3 revealed differential regulation of genes associated with pathways important for learning and memory and altered splicing of Nrxn3. Furthermore, circNrxn3 knock-down enhanced sucrose self-administration and motivation for sucrose. Using RNA-immunoprecipitation, we report binding of circNrxn3 to the known Nrxn3 splicing factor SAM68. circNrxn3 is the first reported circRNA capable of regulating reward behavior and circNrxn3-mediated interactions with SAM68 may impact subsequent downstream processing of RNAs such as the regulation of gene expression and splicing.
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Affiliation(s)
- Konrad R Dabrowski
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA; Department of Biology, Temple University, Philadelphia, PA, USA
| | - Gabriele Floris
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA; Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Aria Gillespie
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA; Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Stephanie E Daws
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA; Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA.
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29
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Fernando MB, Fan Y, Zhang Y, Kammourh S, Murphy AN, Ghorbani S, Onatzevitch R, Pero A, Padilla C, Flaherty EK, Prytkova IK, Cao L, Williams S, Fang G, Slesinger PA, Brennand KJ. Precise Therapeutic Targeting of Distinct NRXN1+/- Mutations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.28.564543. [PMID: 37961635 PMCID: PMC10634884 DOI: 10.1101/2023.10.28.564543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
As genetic studies continue to identify risk loci that are significantly associated with risk for neuropsychiatric disease, a critical unanswered question is the extent to which diverse mutations--sometimes impacting the same gene-- will require tailored therapeutic strategies. Here we consider this in the context of rare neuropsychiatric disorder-associated copy number variants (2p16.3) resulting in heterozygous deletions in NRXN1, a pre-synaptic cell adhesion protein that serves as a critical synaptic organizer in the brain. Complex patterns of NRXN1 alternative splicing are fundamental to establishing diverse neurocircuitry, vary between the cell types of the brain, and are differentially impacted by unique (non-recurrent) deletions. We contrast the cell-type-specific impact of patient-specific mutations in NRXN1 using human induced pluripotent stem cells, finding that perturbations in NRXN1 splicing result in divergent cell-type-specific synaptic outcomes. Via distinct loss-of-function (LOF) and gain-of-function (GOF) mechanisms, NRXN1+/- deletions cause decreased synaptic activity in glutamatergic neurons, yet increased synaptic activity in GABAergic neurons. Stratification of patients by LOF and GOF mechanisms will facilitate individualized restoration of NRXN1 isoform repertoires; towards this, antisense oligonucleotides knockdown mutant isoform expression and alters synaptic transcriptional signatures, while treatment with β-estradiol rescues synaptic function in glutamatergic neurons. Given the increasing number of mutations predicted to engender both LOF and GOF mechanisms in brain disease, our findings add nuance to future considerations of precision medicine.
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Affiliation(s)
- Michael B. Fernando
- Graduate School of Biomedical Science, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Black Family Stem Cell Institute, Pamela Sklar Division of Psychiatric Genomics, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06520
| | - Yu Fan
- Department of Genetics and Genomics, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Yanchun Zhang
- Department of Genetics and Genomics, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Sarah Kammourh
- Department of Genetics and Genomics, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Aleta N. Murphy
- Graduate School of Biomedical Science, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Black Family Stem Cell Institute, Pamela Sklar Division of Psychiatric Genomics, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Sadaf Ghorbani
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06520
- Haukeland University Hospital, Bergen, Norway
| | - Ryan Onatzevitch
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Adriana Pero
- Department of Genetics and Genomics, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Christopher Padilla
- Department of Genetics and Genomics, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Erin K. Flaherty
- Graduate School of Biomedical Science, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Iya K. Prytkova
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Lei Cao
- Department of Genetics and Genomics, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Sarah Williams
- Graduate School of Biomedical Science, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Genetics and Genomics, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Black Family Stem Cell Institute, Pamela Sklar Division of Psychiatric Genomics, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Gang Fang
- Department of Genetics and Genomics, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Paul A. Slesinger
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Kristen J. Brennand
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Genetics and Genomics, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Black Family Stem Cell Institute, Pamela Sklar Division of Psychiatric Genomics, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06520
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30
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Traenkner D, Shennib O, Johnson A, Weinbrom A, Taylor MR, Williams ME. Modular Splicing Is Linked to Evolution in the Synapse-Specificity Molecule Kirrel3. eNeuro 2023; 10:ENEURO.0253-23.2023. [PMID: 37977826 DOI: 10.1523/eneuro.0253-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 11/09/2023] [Accepted: 11/13/2023] [Indexed: 11/19/2023] Open
Abstract
Kirrel3 is a cell-adhesion molecule that instructs the formation of specific synapses during brain development in mouse and Kirrel3 variants may be risk factors for autism and intellectual disabilities in humans. Kirrel3 is predicted to undergo alternative splicing but brain isoforms have not been studied. Here, we present the first in-depth characterization of Kirrel3 isoform diversity in brain using targeted, long-read mRNA sequencing of mouse hippocampus. We identified 19 isoforms with predicted transmembrane and secreted forms and show that even rare isoforms generate detectable protein in the brain. We also analyzed publicly-available long-read mRNA databases from human brain tissue and found 11 Kirrel3 isoforms that, similar to mouse, encode transmembrane and secreted forms. In mice and humans, Kirrel3 diversity arises from alternative, independent use of protein-domain coding exons and alternative early translation-stop signals. Intriguingly, the alternatively spliced exons appear at branch points in the chordate phylogenetic tree, including one exon only found in humans and their closest living relatives, the great apes. Together, these results validate a simple pipeline for analyzing isoform diversity in genes with low expression and suggest that Kirrel3 function is fine-tuned by alternative splicing and may play a role in brain evolution.
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Affiliation(s)
- Dimitri Traenkner
- Department of Neurobiology, University of Utah, School of Medicine, Salt Lake City, UT 84112
| | - Omar Shennib
- Department of Neurobiology, University of Utah, School of Medicine, Salt Lake City, UT 84112
| | - Alyssa Johnson
- Department of Neurobiology, University of Utah, School of Medicine, Salt Lake City, UT 84112
| | - Adam Weinbrom
- Department of Neurobiology, University of Utah, School of Medicine, Salt Lake City, UT 84112
| | - Matthew R Taylor
- Department of Neurobiology, University of Utah, School of Medicine, Salt Lake City, UT 84112
| | - Megan E Williams
- Department of Neurobiology, University of Utah, School of Medicine, Salt Lake City, UT 84112
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Kjer-Hansen P, Weatheritt RJ. The function of alternative splicing in the proteome: rewiring protein interactomes to put old functions into new contexts. Nat Struct Mol Biol 2023; 30:1844-1856. [PMID: 38036695 DOI: 10.1038/s41594-023-01155-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 10/17/2023] [Indexed: 12/02/2023]
Abstract
Alternative splicing affects more than 95% of multi-exon genes in the human genome. These changes affect the proteome in a myriad of ways. Here, we review our understanding of the breadth of these changes from their effect on protein structure to their influence on interactions. These changes encompass effects on nucleic acid binding in the nucleus to protein-carbohydrate interactions in the extracellular milieu, altering interactions involving all major classes of biological molecules. Protein isoforms have profound influences on cellular and tissue physiology, for example, by shaping neuronal connections, enhancing insulin secretion by pancreatic beta cells and allowing for alternative viral defense strategies in stem cells. More broadly, alternative splicing enables repurposing proteins from one context to another and thereby contributes to both the evolution of new traits as well as the creation of disease-specific interactomes that drive pathological phenotypes. In this Review, we highlight this universal character of alternative splicing as a central regulator of protein function with implications for almost every biological process.
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Affiliation(s)
- Peter Kjer-Hansen
- EMBL Australia, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.
- St. Vincent Clinical School, University of New South Wales, Darlinghurst, New South Wales, Australia.
| | - Robert J Weatheritt
- EMBL Australia, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia.
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia.
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Bastien BL, Cowen MH, Hart MP. Distinct neurexin isoforms cooperate to initiate and maintain foraging activity. Transl Psychiatry 2023; 13:367. [PMID: 38036526 PMCID: PMC10689797 DOI: 10.1038/s41398-023-02668-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 10/24/2023] [Accepted: 11/13/2023] [Indexed: 12/02/2023] Open
Abstract
Neurexins are synaptic adhesion molecules that play diverse roles in synaptic development, function, maintenance, and plasticity. Neurexin genes have been associated with changes in human behavior, where variants in NRXN1 are associated with autism, schizophrenia, and Tourette syndrome. While NRXN1, NRXN2, and NRXN3 all encode major α and β isoforms, NRXN1 uniquely encodes a γ isoform, for which mechanistic roles in behavior have yet to be defined. Here, we show that both α and γ isoforms of neurexin/nrx-1 are required for the C. elegans behavioral response to food deprivation, a sustained period of hyperactivity upon food loss. We find that the γ isoform regulates initiation and the α isoform regulates maintenance of the behavioral response to food deprivation, demonstrating cooperative function of multiple nrx-1 isoforms in regulating a sustained behavior. The γ isoform alters monoamine signaling via octopamine, relies on specific expression of NRX-1 isoforms throughout the relevant circuit, and is independent of neuroligin/nlg-1, the canonical trans-synaptic partner of nrx-1. The α isoform regulates the pre-synaptic structure of the octopamine producing RIC neuron and its maintenance role is conditional on neuroligin/nlg-1. Collectively, these results demonstrate that neurexin isoforms can have separate behavioral roles and act cooperatively across neuronal circuits to modify behavior, highlighting the need to directly analyze and consider all isoforms when defining the contribution of neurexins to behavior.
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Affiliation(s)
- Brandon L Bastien
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Mara H Cowen
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Michael P Hart
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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Mu Y, Li J, Zhang S, Zhong F, Zhang X, Song J, Yuan H, Tian T, Hu Y. Role of LncMALAT1-miR-141-3p/200a-3p-NRXN1 Axis in the Impairment of Learning and Memory Capacity in ADHD. Physiol Res 2023; 72:645-656. [PMID: 38015763 PMCID: PMC10751048 DOI: 10.33549/physiolres.935011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 06/27/2023] [Indexed: 01/05/2024] Open
Abstract
As a prevalent neurodevelopmental disease, attention-deficit hyperactivity disorder (ADHD) impairs the learning and memory capacity, and so far, there has been no available treatment option for long-term efficacy. Alterations in gene regulation and synapse-related proteins influence learning and memory capacity; nevertheless, the regulatory mechanism of synapse-related protein synthesis is still unclear in ADHD. LncRNAs have been found participating in regulating genes in multiple disorders. For instance, lncRNA Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT1) has an essential regulatory function in numerous psychiatric diseases. However, how MALAT1 influences synapse-related protein synthesis in ADHD remains largely unknown. Here, our study found that MALAT1 decreased in the hippocampus tissue of spontaneously hypertensive rats (SHRs) compared to the standard controls, Wistar Kyoto (WKY) rats. Subsequent experiments revealed that MALAT1 enhanced the expression of neurexin 1 (NRXN1), which promoted the synapse-related genes (SYN1, PSD95, and GAP43) expression. Then, the bioinformatic analyses predicted that miR-141-3p and miR-200a-3p, microRNAs belonging to miR-200 family and sharing same seed sequence, could interact with MALAT1 and NRXN1 mRNA, which were further confirmed by luciferase report assays. Finally, rescue experiments indicated that MALAT1 influenced the expression of NRXN1 by sponging miR-141-3p/200a-3p. All data verified our hypothesis that MALAT1 regulated synapse-related proteins (SYN1, PSD95, and GAP43) through the MALAT1-miR-141-3p/200a-3p-NRXN1 axis in ADHD. Our research underscored a novel role of MALAT1 in the pathogenesis of impaired learning and memory capacity in ADHD and may shed more light on developing diagnostic biomarkers and more effective therapeutic interventions for individuals with ADHD.
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Affiliation(s)
- Y Mu
- The First Clinical Medical College of Nanjing Medical University, Nanjing, Jiangsu, China; Department of Children's Health Care, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Maternal and Child Health Care Hospital, Nanjing, Jiangsu, China. ,
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Frankel EB, Tiroumalechetty A, Henry PS, Su Z, Wu Y, Kurshan PT. Protein-lipid interactions drive presynaptic assembly upstream of cell adhesion molecules. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.17.567618. [PMID: 38014115 PMCID: PMC10680821 DOI: 10.1101/2023.11.17.567618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Textbook models of synaptogenesis position cell adhesion molecules such as neurexin as initiators of synapse assembly. Here we discover a mechanism for presynaptic assembly that occurs prior to neurexin recruitment, while supporting a role for neurexin in synapse maintenance. We find that the cytosolic active zone scaffold SYD-1 interacts with membrane phospholipids to promote active zone protein clustering at the plasma membrane, and subsequently recruits neurexin to stabilize those clusters. Employing molecular dynamics simulations to model intrinsic interactions between SYD-1 and lipid bilayers followed by in vivo tests of these predictions, we find that PIP2-interacting residues in SYD-1's C2 and PDZ domains are redundantly necessary for proper active zone assembly. Finally, we propose that the uncharacterized yet evolutionarily conserved short γ isoform of neurexin represents a minimal neurexin sequence that can stabilize previously assembled presynaptic clusters, potentially a core function of this critical protein.
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Affiliation(s)
- Elisa B Frankel
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461
| | | | - Parise S Henry
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Zhaoqian Su
- Data Science Institute, Vanderbilt University, 1001 19th Ave S, Nashville, TN, 37212
| | - Yinghao Wu
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Peri T Kurshan
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461
- Lead Contact
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35
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Rupareliya VP, Singh AA, Butt AM, A H, Kumar H. The "molecular soldiers" of the CNS: Astrocytes, a comprehensive review on their roles and molecular signatures. Eur J Pharmacol 2023; 959:176048. [PMID: 37758010 DOI: 10.1016/j.ejphar.2023.176048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 08/24/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023]
Abstract
For a long time, neurons held the position of central players in the nervous system. Since there are far more astrocytes than neurons in the brain, it makes us wonder if these cells just take up space and support the neurons or if they are actively participating in central nervous system (CNS) homeostasis. Now, astrocytes' contribution to CNS physiology is appreciated as they are known to regulate ion and neurotransmitter levels, synapse formation and elimination, blood-brain barrier integrity, immune function, cerebral blood flow, and many more. In many neurological and psychiatric disorders, astrocyte functions are altered. Advancements in microscopic and transcriptomic tools revealed populations of astrocytes with varied morphology, electrophysiological properties, and transcriptomic profiles. Neuron-circuit-specific functions and neuron-specific interactions of astroglial subpopulations are found, which suggests that diversity is essential in carrying out diverse region-specific CNS functions. Investigations on heterogeneous astrocyte populations are revealing new astrocyte functions and their role in pathological conditions, opening a new therapeutic avenue for targeting neurological conditions. The true extent of astrocytic heterogeneity and its functional implications are yet to be fully explored. This review summarizes essential astrocytic functions and their relevance in pathological conditions and discusses astrocytic diversity in relation to morphology, function, and gene expression throughout the CNS.
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Affiliation(s)
- Vimal P Rupareliya
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Gandhinagar, Gujarat 382355, India
| | - Aditya A Singh
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Gandhinagar, Gujarat 382355, India
| | - Ayub Mohammed Butt
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Gandhinagar, Gujarat 382355, India
| | - Hariharan A
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Gandhinagar, Gujarat 382355, India
| | - Hemant Kumar
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Gandhinagar, Gujarat 382355, India.
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36
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Connor SA, Siddiqui TJ. Synapse organizers as molecular codes for synaptic plasticity. Trends Neurosci 2023; 46:971-985. [PMID: 37652840 DOI: 10.1016/j.tins.2023.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 07/13/2023] [Accepted: 08/03/2023] [Indexed: 09/02/2023]
Abstract
Synapse organizing proteins are multifaceted molecules that coordinate the complex processes of brain development and plasticity at the level of individual synapses. Their importance is demonstrated by the major brain disorders that emerge when their function is compromised. The mechanisms whereby the various families of organizers govern synapses are diverse, but converge on the structure, function, and plasticity of synapses. Therefore, synapse organizers regulate how synapses adapt to ongoing activity, a process central for determining the developmental trajectory of the brain and critical to all forms of cognition. Here, we explore how synapse organizers set the conditions for synaptic plasticity and the associated molecular events, which eventually link to behavioral features of neurodevelopmental and neuropsychiatric disorders. We also propose central questions on how synapse organizers influence network function through integrating nanoscale and circuit-level organization of the brain.
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Affiliation(s)
- Steven A Connor
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada.
| | - Tabrez J Siddiqui
- PrairieNeuro Research Centre, Kleysen Institute for Advanced Medicine, Health Sciences Centre, Winnipeg, MB R3E 0Z3, Canada; Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada; The Children's Hospital Research Institute of Manitoba, Winnipeg, MB R3E 3P4, Canada; Program in Biomedical Engineering, University of Manitoba, Winnipeg, MB, Canada.
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37
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Boahen A, Hu D, Adams MJ, Nicholls PK, Greene WK, Ma B. Bidirectional crosstalk between the peripheral nervous system and lymphoid tissues/organs. Front Immunol 2023; 14:1254054. [PMID: 37767094 PMCID: PMC10520967 DOI: 10.3389/fimmu.2023.1254054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 08/25/2023] [Indexed: 09/29/2023] Open
Abstract
The central nervous system (CNS) influences the immune system generally by regulating the systemic concentration of humoral substances (e.g., cortisol and epinephrine), whereas the peripheral nervous system (PNS) communicates specifically with the immune system according to local interactions/connections. An imbalance between the components of the PNS might contribute to pathogenesis and the further development of certain diseases. In this review, we have explored the "thread" (hardwiring) of the connections between the immune system (e.g., primary/secondary/tertiary lymphoid tissues/organs) and PNS (e.g., sensory, sympathetic, parasympathetic, and enteric nervous systems (ENS)) in health and disease in vitro and in vivo. Neuroimmune cell units provide an anatomical and physiological basis for bidirectional crosstalk between the PNS and the immune system in peripheral tissues, including lymphoid tissues and organs. These neuroimmune interactions/modulation studies might greatly contribute to a better understanding of the mechanisms through which the PNS possibly affects cellular and humoral-mediated immune responses or vice versa in health and diseases. Physical, chemical, pharmacological, and other manipulations of these neuroimmune interactions should bring about the development of practical therapeutic applications for certain neurological, neuroimmunological, infectious, inflammatory, and immunological disorders/diseases.
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Affiliation(s)
- Angela Boahen
- Department of Medical Microbiology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Seri-Kembangan, Selangor, Malaysia
| | - Dailun Hu
- Department of Pathogenic Biology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Murray J. Adams
- School of Medical, Molecular and Forensic Sciences, Murdoch University, Murdoch, WA, Australia
| | - Philip K. Nicholls
- School of Medical, Molecular and Forensic Sciences, Murdoch University, Murdoch, WA, Australia
| | - Wayne K. Greene
- School of Medical, Molecular and Forensic Sciences, Murdoch University, Murdoch, WA, Australia
| | - Bin Ma
- School of Medical, Molecular and Forensic Sciences, Murdoch University, Murdoch, WA, Australia
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38
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Fertan E, Wong AA, Montbrun TSGD, Purdon MK, Roddick KM, Yamamoto T, Brown RE. Early postnatal development of the MDGA2 +/- mouse model of synaptic dysfunction. Behav Brain Res 2023; 452:114590. [PMID: 37499910 DOI: 10.1016/j.bbr.2023.114590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/13/2023] [Accepted: 07/19/2023] [Indexed: 07/29/2023]
Abstract
Synaptic dysfunction underlies many neurodevelopmental disorders (NDDs). The membrane-associated mucin domain-containing glycosylphosphatidylinositol anchor proteins (MDGAs) regulate synaptic development by modulating neurexin-neuroligin complex formation. Since understanding the neurodevelopmental profile and the sex-based differences in the manifestation of the symptoms of NDDs is important for their early diagnosis, we tested a mouse model haploinsufficient for MDGA2 (MDGA2+/-) on a neurodevelopmental test battery, containing sensory, motor, and cognitive measures, as well as ultrasonic vocalizations. When male and female MDGA2+/- and wildtype (WT) C57BL/6 J mice were examined from 2 to 23 days of age using this test battery, genotype and sex differences in body weight, sensory-motor processes, and ultrasonic vocalizations were observed. The auditory startle reflex appeared earlier in the MDGA2+/- than in WT mice and the MDGA2+/- mice produced fewer ultrasonic vocalizations. The MDGA2+/- mice showed reduced locomotion and rearing than WT mice in the open field after 17 days of age and spent less time investigating a novel object than WT mice at 21 days of age. Female MDGA2+/- mice weighed less than WT females and showed lower grip strength, indicating a delay in sensory-motor development in MDGA2+/- mice, which appears to be more pronounced in females than males. The behavioural phenotypes resulting from MDGA2 haploinsufficiency suggests that it shows delayed development of motor behaviour, grip strength and exploratory behaviour, non-social phenotypes of NDDs.
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Affiliation(s)
- Emre Fertan
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Aimée A Wong
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | | | - Michaela K Purdon
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Kyle M Roddick
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Tohru Yamamoto
- Department of Molecular Neurobiology, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kagawa 761-0793, Japan
| | - Richard E Brown
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada.
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39
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Mori T, Zhou M, Tabuchi K. Diverse Clinical Phenotypes of CASK-Related Disorders and Multiple Functional Domains of CASK Protein. Genes (Basel) 2023; 14:1656. [PMID: 37628707 PMCID: PMC10454856 DOI: 10.3390/genes14081656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 08/17/2023] [Accepted: 08/17/2023] [Indexed: 08/27/2023] Open
Abstract
CASK-related disorders are a form of rare X-linked neurological diseases and most of the patients are females. They are characterized by several symptoms, including microcephaly with pontine and cerebellar hypoplasia (MICPCH), epilepsy, congenital nystagmus, and neurodevelopmental disorders. Whole-genome sequencing has identified various mutations, including nonsense and missense mutations, from patients with CASK-related disorders, revealing correlations between specific mutations and clinical phenotypes. Notably, missense mutations associated with epilepsy and intellectual disability were found throughout the whole region of the CASK protein, while missense mutations related to microcephaly and MICPCH were restricted in certain domains. To investigate the pathophysiology of CASK-related disorders, research groups have employed diverse methods, including the generation of CASK knockout mice and the supplementation of CASK to rescue the phenotypes. These approaches have yielded valuable insights into the identification of functional domains of the CASK protein associated with a specific phenotype. Additionally, recent advancements in the AI-based prediction of protein structure, such as AlphaFold2, and the application of genome-editing techniques to generate CASK mutant mice carrying missense mutations from patients with CASK-related disorders, allow us to understand the pathophysiology of CASK-related disorders in more depth and to develop novel therapeutic methods for the fundamental treatment of CASK-related disorders.
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Affiliation(s)
- Takuma Mori
- Department of Neuroinnovation, Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Matsumoto 390-8621, Japan;
- Department of Molecular and Cellular Physiology, Shinshu University School of Medicine, Matsumoto 390-8621, Japan;
| | - Mengyun Zhou
- Department of Molecular and Cellular Physiology, Shinshu University School of Medicine, Matsumoto 390-8621, Japan;
| | - Katsuhiko Tabuchi
- Department of Neuroinnovation, Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Matsumoto 390-8621, Japan;
- Department of Molecular and Cellular Physiology, Shinshu University School of Medicine, Matsumoto 390-8621, Japan;
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40
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Sclip A, Südhof TC. Combinatorial expression of neurexins and LAR-type phosphotyrosine phosphatase receptors instructs assembly of a cerebellar circuit. Nat Commun 2023; 14:4976. [PMID: 37591863 PMCID: PMC10435579 DOI: 10.1038/s41467-023-40526-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 07/20/2023] [Indexed: 08/19/2023] Open
Abstract
Synaptic adhesion molecules (SAMs) shape the structural and functional properties of synapses and thereby control the information processing power of neural circuits. SAMs are broadly expressed in the brain, suggesting that they may instruct synapse formation and specification via a combinatorial logic. Here, we generate sextuple conditional knockout mice targeting all members of the two major families of presynaptic SAMs, Neurexins and leukocyte common antigen-related-type receptor phospho-tyrosine phosphatases (LAR-PTPRs), which together account for the majority of known trans-synaptic complexes. Using synapses formed by cerebellar Purkinje cells onto deep cerebellar nuclei as a model system, we confirm that Neurexins and LAR-PTPRs themselves are not essential for synapse assembly. The combinatorial deletion of both neurexins and LAR-PTPRs, however, decreases Purkinje-cell synapses on deep cerebellar nuclei, the major output pathway of cerebellar circuits. Consistent with this finding, combined but not separate deletions of neurexins and LAR-PTPRs impair motor behaviors. Thus, Neurexins and LAR-PTPRs are together required for the assembly of a functional cerebellar circuit.
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Affiliation(s)
- Alessandra Sclip
- Department of Cellular and Molecular Physiology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
| | - Thomas C Südhof
- Department of Cellular and Molecular Physiology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, 94305, USA.
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41
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Dowling P, Zweyer M, Sabir H, Henry M, Meleady P, Swandulla D, Ohlendieck K. Mass spectrometry-based proteomic characterization of the middle-aged mouse brain for animal model research of neuromuscular diseases. Eur J Transl Myol 2023; 33:11553. [PMID: 37545360 PMCID: PMC10583138 DOI: 10.4081/ejtm.2023.11553] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 07/28/2023] [Indexed: 08/08/2023] Open
Abstract
Neuromuscular diseases with primary muscle wasting symptoms may also display multi-systemic changes in the body and exhibit secondary pathophysiological alterations in various non-muscle tissues. In some cases, this includes proteome-wide alterations and/or adaptations in the central nervous system. Thus, in order to provide an improved bioanalytical basis for the comprehensive evaluation of animal models that are routinely used in muscle research, this report describes the mass spectrometry-based proteomic characterization of the mouse brain. Crude tissue extracts were examined by bottom-up proteomics and detected 4558 distinct protein species. The detailed analysis of the brain proteome revealed the presence of abundant cellular proteoforms in the neuronal cytoskeleton, as well as various brain region enriched proteins, including markers of the cerebral cortex, cerebellum, hippocampus and the olfactory bulb. Neuroproteomic markers of specific cell types in the brain were identified in association with various types of neurons and glia cells. Markers of subcellular structures were established for the plasmalemma, nucleus, endoplasmic reticulum, mitochondria and other crucial organelles, as well as synaptic components that are involved in presynaptic vesicle docking, neurotransmitter release and synapse remodelling.
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Affiliation(s)
- Paul Dowling
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Co. Kildare, Ireland; Kathleen Lonsdale Institute for Human Health Research, Maynooth University, Maynooth, Co. Kildare.
| | - Margit Zweyer
- Department of Neonatology and Paediatric Intensive Care, Children's Hospital, University of Bonn, Bonn, Germany; German Centre for Neurodegenerative Diseases, University of Bonn, Bonn.
| | - Hemmen Sabir
- Department of Neonatology and Paediatric Intensive Care, Children's Hospital, University of Bonn, Bonn, Germany; German Centre for Neurodegenerative Diseases, University of Bonn, Bonn.
| | - Michael Henry
- National Institute for Cellular Biotechnology, Dublin City University, Dublin.
| | - Paula Meleady
- National Institute for Cellular Biotechnology, Dublin City University, Dublin.
| | - Dieter Swandulla
- Institute of Physiology, Medical Faculty, University of Bonn, Bonn.
| | - Kay Ohlendieck
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Co. Kildare, Ireland; Kathleen Lonsdale Institute for Human Health Research, Maynooth University, Maynooth, Co. Kildare.
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42
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Dai DL, Li M, Lee EB. Human Alzheimer's disease reactive astrocytes exhibit a loss of homeostastic gene expression. Acta Neuropathol Commun 2023; 11:127. [PMID: 37533101 PMCID: PMC10398957 DOI: 10.1186/s40478-023-01624-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 07/14/2023] [Indexed: 08/04/2023] Open
Abstract
Astrocytes are one of the brain's major cell types and are responsible for maintaining neuronal homeostasis via regulating the extracellular environment, providing metabolic support, and modulating synaptic activity. In neurodegenerative diseases, such as Alzheimer's disease, astrocytes can take on a hypertrophic appearance. These reactive astrocytes are canonically associated with increases in cytoskeletal proteins, such as glial fibrillary acidic protein and vimentin. However, the molecular alterations that characterize astrocytes in human disease tissues have not been extensively studied with single cell resolution. Using single nucleus RNA sequencing data from normal, pathologic aging, and Alzheimer's disease brains, we identified the transcriptomic changes associated with reactive astrocytes. Deep learning-based clustering algorithms denoised expression data for 17,012 genes and clustered 15,529 astrocyte nuclei, identifying protoplasmic, gray matter and fibrous, white matter astrocyte clusters. RNA trajectory analyses revealed a spectrum of reactivity within protoplasmic astrocytes characterized by a modest increase of reactive genes and a marked decrease in homeostatic genes. Amyloid but not tau pathology correlated with astrocyte reactivity. To identify reactivity-associated genes, linear regressions of gene expression versus reactivity were used to identify the top 52 upregulated and 144 downregulated genes. Gene Ontology analysis revealed that upregulated genes were associated with cellular growth, responses to metal ions, inflammation, and proteostasis. Downregulated genes were involved in cellular interactions, neuronal development, ERBB signaling, and synapse regulation. Transcription factors were significantly enriched among the downregulated genes. Using co-immunofluorescence staining of Alzheimer's disease brain tissues, we confirmed pathologic downregulation of ERBB4 and transcription factor NFIA in reactive astrocytes. Our findings reveal that protoplasmic, gray matter astrocytes in Alzheimer's disease exist within a spectrum of reactivity that is marked by a strong loss of normal function.
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Affiliation(s)
- David L Dai
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, 19104, USA
| | - Mingyao Li
- Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, 19104, USA
| | - Edward B Lee
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, 19104, USA.
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43
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Südhof TC. Cerebellin-neurexin complexes instructing synapse properties. Curr Opin Neurobiol 2023; 81:102727. [PMID: 37209532 DOI: 10.1016/j.conb.2023.102727] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 04/20/2023] [Accepted: 04/21/2023] [Indexed: 05/22/2023]
Abstract
Cerebellins (Cbln1-4) are secreted adaptor proteins that connect presynaptic neurexins (Nrxn1-3) to postsynaptic ligands (GluD1/2 for Cbln1-3 vs. DCC and Neogenin-1 for Cbln4). Classical studies demonstrated that neurexin-Cbln1-GluD2 complexes organize cerebellar parallel-fiber synapses, but the role of cerebellins outside of the cerebellum has only recently been clarified. In synapses of the hippocampal subiculum and prefrontal cortex, Nrxn1-Cbln2-GluD1 complexes strikingly upregulate postsynaptic NMDA-receptors, whereas Nrxn3-Cbln2-GluD1 complexes conversely downregulate postsynaptic AMPA-receptors. At perforant-path synapses in the dentate gyrus, in contrast, neurexin/Cbln4/Neogenin-1 complexes are essential for LTP without affecting basal synaptic transmission or NMDA- or AMPA-receptors. None of these signaling pathways are required for synapse formation. Thus, outside of the cerebellum neurexin/cerebellin complexes regulate synapse properties by activating specific downstream receptors.
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Affiliation(s)
- Thomas C Südhof
- Dept. of Molecular and Cellular Physiology and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford CA 94305, USA.
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44
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Lu H, Zuo L, Roddick KM, Zhang P, Oku S, Garden J, Ge Y, Bellefontaine M, Delhaye M, Brown RE, Craig AM. Alternative splicing and heparan sulfation converge on neurexin-1 to control glutamatergic transmission and autism-related behaviors. Cell Rep 2023; 42:112714. [PMID: 37384525 DOI: 10.1016/j.celrep.2023.112714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 04/16/2023] [Accepted: 06/13/2023] [Indexed: 07/01/2023] Open
Abstract
Neurexin synaptic organizing proteins are central to a genetic risk pathway in neuropsychiatric disorders. Neurexins also exemplify molecular diversity in the brain, with over a thousand alternatively spliced forms and further structural heterogeneity contributed by heparan sulfate glycan modification. Yet, interactions between these modes of post-transcriptional and post-translational modification have not been studied. We reveal that these regulatory modes converge on neurexin-1 splice site 5 (S5): the S5 insert increases the number of heparan sulfate chains. This is associated with reduced neurexin-1 protein level and reduced glutamatergic neurotransmitter release. Exclusion of neurexin-1 S5 in mice boosts neurotransmission without altering the AMPA/NMDA ratio and shifts communication and repetitive behavior away from phenotypes associated with autism spectrum disorders. Thus, neurexin-1 S5 acts as a synaptic rheostat to impact behavior through the intersection of RNA processing and glycobiology. These findings position NRXN1 S5 as a potential therapeutic target to restore function in neuropsychiatric disorders.
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Affiliation(s)
- Hong Lu
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, BC V6T 2B5, Canada
| | - Long Zuo
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, BC V6T 2B5, Canada
| | - Kyle M Roddick
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Peng Zhang
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, BC V6T 2B5, Canada
| | - Shinichiro Oku
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, BC V6T 2B5, Canada
| | - Jessica Garden
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Yuan Ge
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, BC V6T 2B5, Canada
| | - Michael Bellefontaine
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Mathias Delhaye
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, BC V6T 2B5, Canada
| | - Richard E Brown
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Ann Marie Craig
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, BC V6T 2B5, Canada.
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45
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Medina-Samamé A, Paller É, Bril MR, Archvadze A, Simões-Abade MBC, Estañol-Cayuela P, LeMaoult C. Role of Neurexins in Alzheimer's Disease. J Neurosci 2023; 43:4194-4196. [PMID: 37286342 DOI: 10.1523/jneurosci.0169-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 04/03/2023] [Accepted: 04/05/2023] [Indexed: 06/09/2023] Open
Affiliation(s)
| | - Éva Paller
- University of Groningen, 9700 AB, Groningen, The Netherlands
| | - Mateo R Bril
- University of Groningen, 9700 AB, Groningen, The Netherlands
| | - Ana Archvadze
- University of Groningen, 9700 AB, Groningen, The Netherlands
| | | | | | - Chloe LeMaoult
- University of Groningen, 9700 AB, Groningen, The Netherlands
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46
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Feichtinger RG, Preisel M, Brugger K, Wortmann SB, Mayr JA. Case Report-An Inherited Loss-of-Function NRXN3 Variant Potentially Causes a Neurodevelopmental Disorder with Autism Consistent with Previously Described 14q24.3-31.1 Deletions. Genes (Basel) 2023; 14:1217. [PMID: 37372397 DOI: 10.3390/genes14061217] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 05/26/2023] [Accepted: 05/31/2023] [Indexed: 06/29/2023] Open
Abstract
BACKGROUND Heterozygous, large-scale deletions at 14q24.3-31.1 affecting the neurexin-3 gene have been associated with neurodevelopmental disorders such as autism. Both "de novo" occurrences and inheritance from a healthy parent suggest incomplete penetrance and expressivity, especially in autism spectrum disorder. NRXN3 encodes neurexin-3, a neuronal cell surface protein involved in cell recognition and adhesion, as well as mediating intracellular signaling. NRXN3 is expressed in two distinct isoforms (alpha and beta) generated by alternative promoters and splicing. MM/Results: Using exome sequencing, we identified a monoallelic frameshift variant c.159_160del (p.Gln54AlafsTer50) in the NRXN3 beta isoform (NM_001272020.2) in a 5-year-old girl with developmental delay, autism spectrum disorder, and behavioral issues. This variant was inherited from her mother, who did not have any medical complaints. DISCUSSION This is the first detailed report of a loss-of-function variant in NRXN3 causing an identical phenotype, as reported for heterozygous large-scale deletions in the same genomic region, thereby confirming NRXN3 as a novel gene for neurodevelopmental disorders with autism.
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Affiliation(s)
- René G Feichtinger
- University Children's Hospital, Salzburger Landeskliniken (SALK) und Paracelsus Medical University (PMU), 5020 Salzburg, Austria
| | - Martin Preisel
- University Children's Hospital, Salzburger Landeskliniken (SALK) und Paracelsus Medical University (PMU), 5020 Salzburg, Austria
| | - Karin Brugger
- University Children's Hospital, Salzburger Landeskliniken (SALK) und Paracelsus Medical University (PMU), 5020 Salzburg, Austria
| | - Saskia B Wortmann
- University Children's Hospital, Salzburger Landeskliniken (SALK) und Paracelsus Medical University (PMU), 5020 Salzburg, Austria
- Amalia Children's Hospital, Radboudumc, 6525 HB Nijmegen, The Netherlands
| | - Johannes A Mayr
- University Children's Hospital, Salzburger Landeskliniken (SALK) und Paracelsus Medical University (PMU), 5020 Salzburg, Austria
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Lee AK, Yi N, Khaled H, Feller B, Takahashi H. SorCS1 inhibits amyloid-β binding to neurexin and rescues amyloid-β-induced synaptic pathology. Life Sci Alliance 2023; 6:e202201681. [PMID: 36697254 PMCID: PMC9880023 DOI: 10.26508/lsa.202201681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 01/13/2023] [Accepted: 01/16/2023] [Indexed: 01/27/2023] Open
Abstract
Amyloid-β oligomers (AβOs), toxic peptide aggregates found in Alzheimer's disease, cause synapse pathology. AβOs interact with neurexins (NRXs), key synaptic organizers, and this interaction dampens normal trafficking and function of NRXs. Axonal trafficking of NRX is in part regulated by its interaction with SorCS1, a protein sorting receptor, but the impact of SorCS1 regulation of NRXs in Aβ pathology was previously unstudied. Here, we show competition between the SorCS1 ectodomain and AβOs for β-NRX binding and rescue effects of the SorCS1b isoform on AβO-induced synaptic pathology. Like AβOs, the SorCS1 ectodomain binds to NRX1β through the histidine-rich domain of NRX1β, and the SorCS1 ectodomain and AβOs compete for NRX1β binding. In cultured hippocampal neurons, SorCS1b colocalizes with NRX1β on the axon surface, and axonal expression of SorCS1b rescues AβO-induced impairment of NRX-mediated presynaptic organization and presynaptic vesicle recycling and AβO-induced structural defects in excitatory synapses. Thus, our data suggest a role for SorCS1 in the rescue of AβO-induced NRX dysfunction and synaptic pathology, providing the basis for a novel potential therapeutic strategy for Alzheimer's disease.
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Affiliation(s)
- Alfred Kihoon Lee
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, Canada
| | - Nayoung Yi
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, Canada
- Department of Medicine, Université de Montréal, Montreal, Canada
| | - Husam Khaled
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, Canada
- Department of Medicine, Université de Montréal, Montreal, Canada
| | - Benjamin Feller
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, Canada
- Department of Medicine, Université de Montréal, Montreal, Canada
| | - Hideto Takahashi
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, Canada
- Department of Medicine, Université de Montréal, Montreal, Canada
- Division of Experimental Medicine, McGill University, Montreal, Canada
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Lee H, Chofflet N, Liu J, Fan S, Lu Z, Resua Rojas M, Penndorf P, Bailey AO, Russell WK, Machius M, Ren G, Takahashi H, Rudenko G. Designer molecules of the synaptic organizer MDGA1 reveal 3D conformational control of biological function. J Biol Chem 2023; 299:104586. [PMID: 36889589 PMCID: PMC10131064 DOI: 10.1016/j.jbc.2023.104586] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 03/08/2023] Open
Abstract
MDGAs (MAM domain-containing glycosylphosphatidylinositol anchors) are synaptic cell surface molecules that regulate the formation of trans-synaptic bridges between neurexins (NRXNs) and neuroligins (NLGNs), which promote synaptic development. Mutations in MDGAs are implicated in various neuropsychiatric diseases. MDGAs bind NLGNs in cis on the postsynaptic membrane and physically block NLGNs from binding to NRXNs. In crystal structures, the six immunoglobulin (Ig) and single fibronectin III domains of MDGA1 reveal a striking compact, triangular shape, both alone and in complex with NLGNs. Whether this unusual domain arrangement is required for biological function or other arrangements occur with different functional outcomes is unknown. Here, we show that WT MDGA1 can adopt both compact and extended 3D conformations that bind NLGN2. Designer mutants targeting strategic molecular elbows in MDGA1 alter the distribution of 3D conformations while leaving the binding affinity between soluble ectodomains of MDGA1 and NLGN2 intact. In contrast, in a cellular context, these mutants result in unique combinations of functional consequences, including altered binding to NLGN2, decreased capacity to conceal NLGN2 from NRXN1β, and/or suppressed NLGN2-mediated inhibitory presynaptic differentiation, despite the mutations being located far from the MDGA1-NLGN2 interaction site. Thus, the 3D conformation of the entire MDGA1 ectodomain appears critical for its function, and its NLGN-binding site on Ig1-Ig2 is not independent of the rest of the molecule. As a result, global 3D conformational changes to the MDGA1 ectodomain via strategic elbows may form a molecular mechanism to regulate MDGA1 action within the synaptic cleft.
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Affiliation(s)
- Hubert Lee
- Deptartment of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA
| | - Nicolas Chofflet
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montréal, Quebec, Canada; Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada
| | - Jianfang Liu
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Shanghua Fan
- Deptartment of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA
| | - Zhuoyang Lu
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Martin Resua Rojas
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montréal, Quebec, Canada
| | - Patrick Penndorf
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montréal, Quebec, Canada
| | - Aaron O Bailey
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
| | - William K Russell
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
| | - Mischa Machius
- Deptartment of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA
| | - Gang Ren
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
| | - Hideto Takahashi
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montréal, Quebec, Canada; Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada; Department of Medicine, Université de Montréal, Montréal, Quebec, Canada; Division of Experimental Medicine, McGill University, Montréal, Quebec, Canada.
| | - Gabby Rudenko
- Deptartment of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA.
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Marcassa G, Dascenco D, de Wit J. Proteomics-based synapse characterization: From proteins to circuits. Curr Opin Neurobiol 2023; 79:102690. [PMID: 36805717 DOI: 10.1016/j.conb.2023.102690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/15/2022] [Accepted: 01/10/2023] [Indexed: 02/19/2023]
Abstract
The highly heterogeneous nature of neuronal cell types and their connections presents a major challenge to the characterization of neural circuits at the protein level. New approaches now enable an increasingly sophisticated dissection of cell type- and cellular compartment-specific proteomes, as well as the profiling of the protein composition of specific synaptic connections. Here, we provide an overview of these approaches and discuss how they hold considerable promise toward unravelling the molecular mechanisms of neural circuit formation and function. Finally, we provide an outlook of technological developments that may bring the characterization of synaptic proteomes at the single-synapse level within reach.
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Affiliation(s)
- Gabriele Marcassa
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Herestraat 49, 3000 Leuven, Belgium
| | - Dan Dascenco
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Herestraat 49, 3000 Leuven, Belgium. https://twitter.com/ddascenco
| | - Joris de Wit
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Herestraat 49, 3000 Leuven, Belgium.
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50
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Fu WY, Ip NY. The role of genetic risk factors of Alzheimer's disease in synaptic dysfunction. Semin Cell Dev Biol 2023; 139:3-12. [PMID: 35918217 DOI: 10.1016/j.semcdb.2022.07.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 07/24/2022] [Accepted: 07/25/2022] [Indexed: 12/31/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease characterized by the progressive deterioration of cognitive functions. Due to the extended global life expectancy, the prevalence of AD is increasing among aging populations worldwide. While AD is a multifactorial disease, synaptic dysfunction is one of the major neuropathological changes that occur early in AD, before clinical symptoms appear, and is associated with the progression of cognitive deterioration. However, the underlying pathological mechanisms leading to this synaptic dysfunction remains unclear. Recent large-scale genomic analyses have identified more than 40 genetic risk factors that are associated with AD. In this review, we discuss the functional roles of these genes in synaptogenesis and synaptic functions under physiological conditions, and how their functions are dysregulated in AD. This will provide insights into the contributions of these encoded proteins to synaptic dysfunction during AD pathogenesis.
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Affiliation(s)
- Wing-Yu Fu
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China; Hong Kong Center for Neurodegenerative Diseases, Hong Kong Science Park, Hong Kong, China
| | - Nancy Y Ip
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China; Hong Kong Center for Neurodegenerative Diseases, Hong Kong Science Park, Hong Kong, China; Guangdong Provincial Key Laboratory of Brain Science, Disease and Drug Development, HKUST Shenzhen Research Institute, Shenzhen-Hong Kong Institute of Brain Science, Shenzhen, Guangdong 518057, China.
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