scholarly journals Neuronal Glycoprotein M6a: An Emerging Molecule in Chemical Synapse Formation and Dysfunction

2021 ◽  
Vol 13 ◽  
Author(s):  
Antonella León ◽  
Gabriela I. Aparicio ◽  
Camila Scorticati
Keyword(s):  
Large Scale ◽  
Molecular Mechanisms ◽  
Neuronal Development ◽  
Synapse Formation ◽  
Disease Risk ◽  
Protein Complexes ◽  
Synaptic Function ◽  
Chemical Synapse ◽  
Gene Target

The cellular and molecular mechanisms underlying neuropsychiatric and neurodevelopmental disorders show that most of them can be categorized as synaptopathies—or damage of synaptic function and plasticity. Synaptic formation and maintenance are orchestrated by protein complexes that are in turn regulated in space and time during neuronal development allowing synaptic plasticity. However, the exact mechanisms by which these processes are managed remain unknown. Large-scale genomic and proteomic projects led to the discovery of new molecules and their associated variants as disease risk factors. Neuronal glycoprotein M6a, encoded by the GPM6A gene is emerging as one of these molecules. M6a has been involved in neuron development and synapse formation and plasticity, and was also recently proposed as a gene-target in various neuropsychiatric disorders where it could also be used as a biomarker. In this review, we provide an overview of the structure and molecular mechanisms by which glycoprotein M6a participates in synapse formation and maintenance. We also review evidence collected from patients carrying mutations in the GPM6A gene; animal models, and in vitro studies that together emphasize the relevance of M6a, particularly in synapses and in neurological conditions.

scholarly journals Identification of Neuronal Pentraxins as Synaptic Binding Partners of C1q and the Involvement of NP1 in Synaptic Pruning in Adult Mice

2021 ◽  
Vol 11 ◽  
Author(s):  
Réka Á. Kovács ◽  
Henrietta Vadászi ◽  
Éva Bulyáki ◽  
György Török ◽  
Vilmos Tóth ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Synapse Formation ◽  
Potential Interaction ◽  
Synaptic Function ◽  
Classical Pathway ◽  
Microglial Phagocytosis ◽  
Classical Complement Pathway ◽  
Adult Mice ◽  
Synaptic Pruning

Elements of the immune system particularly that of innate immunity, play important roles beyond their traditional tasks in host defense, including manifold roles in the nervous system. Complement-mediated synaptic pruning is essential in the developing and healthy functioning brain and becomes aberrant in neurodegenerative disorders. C1q, component of the classical complement pathway, plays a central role in tagging synapses for elimination; however, the underlying molecular mechanisms and interaction partners are mostly unknown. Neuronal pentraxins (NPs) are involved in synapse formation and plasticity, moreover, NP1 contributes to cell death and neurodegeneration under adverse conditions. Here, we investigated the potential interaction between C1q and NPs, and its role in microglial phagocytosis of synapses in adult mice. We verified in vitro that NPs interact with C1q, as well as activate the complement system. Flow cytometry, immunostaining and co-immunoprecipitation showed that synapse-bound C1q colocalizes and interacts with NPs. High-resolution confocal microscopy revealed that microglia-surrounded C1q-tagged synapses are NP1 positive. We have also observed the synaptic occurrence of C4 suggesting that activation of the classical pathway cannot be ruled out in synaptic plasticity in healthy adult animals. In summary, our results indicate that NPs play a regulatory role in the synaptic function of C1q. Whether this role can be intensified upon pathological conditions, such as in Alzheimer’s disease, is to be disclosed.

scholarly journals EGCG binds intrinsically disordered N-terminal domain of p53 and disrupts p53-MDM2 interaction

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jing Zhao ◽  
Alan Blayney ◽  
Xiaorong Liu ◽  
Lauren Gandy ◽  
Weihua Jin ◽  
...  
Keyword(s):  
Large Scale ◽  
Molecular Mechanisms ◽  
Epigallocatechin Gallate ◽  
Cancer Drug ◽  
Dynamic Interactions ◽  
Cancer Drug Discovery ◽  
Intrinsically Disordered ◽  
Terminal Domain ◽  
Cancerous Cells

AbstractEpigallocatechin gallate (EGCG) from green tea can induce apoptosis in cancerous cells, but the underlying molecular mechanisms remain poorly understood. Using SPR and NMR, here we report a direct, μM interaction between EGCG and the tumor suppressor p53 (KD = 1.6 ± 1.4 μM), with the disordered N-terminal domain (NTD) identified as the major binding site (KD = 4 ± 2 μM). Large scale atomistic simulations (>100 μs), SAXS and AUC demonstrate that EGCG-NTD interaction is dynamic and EGCG causes the emergence of a subpopulation of compact bound conformations. The EGCG-p53 interaction disrupts p53 interaction with its regulatory E3 ligase MDM2 and inhibits ubiquitination of p53 by MDM2 in an in vitro ubiquitination assay, likely stabilizing p53 for anti-tumor activity. Our work provides insights into the mechanisms for EGCG’s anticancer activity and identifies p53 NTD as a target for cancer drug discovery through dynamic interactions with small molecules.

scholarly journals The Organotypic Longitudinal Spinal Cord Slice Culture for Stem Cell Study

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Joanna Sypecka ◽  
Sylwia Koniusz ◽  
Maria Kawalec ◽  
Anna Sarnowska
Keyword(s):  
Spinal Cord ◽  
Molecular Mechanisms ◽  
Synapse Formation ◽  
Scientific Basis ◽  
Slice Culture ◽  
Spinal Cord Regeneration ◽  
Spinal Cord Slice ◽  
Detailed Method ◽  
Cord Injury

The objective of this paper is to describe in detail the method of organotypic longitudinal spinal cord slice culture and the scientific basis for its potential utility. The technique is based on the interface method, which was described previously and thereafter was modified in our laboratory. The most important advantage of the presented model is the preservation of the intrinsic spinal cord fiber tract and the ventrodorsal polarity of the spinal cord. All the processes occurring during axonal growth, regeneration, synapse formation, and myelination could be visualized while being culturedin vitrofor up to 4-5 weeks after the slices had been isolated. Both pups and adult animals can undergo the same, equally efficient procedures when going by the protocol in question. The urgent need for an appropriatein vitromodel for spinal cord regeneration results from a greater number of clinical trials concerning regenerative medicine in the spinal cord injury and from still insufficient knowledge of the molecular mechanisms involved in the neuroreparative processes. The detailed method of organotypic longitudinal spinal cord slice culture is accompanied by examples of its application to studying biological processes to which both the CNS inhabiting and grafted cells are subjected.

scholarly journals Superfluous Role of Mammalian Septins 3 and 5 in Neuronal Development and Synaptic Transmission

2008 ◽  
Vol 28 (23) ◽  
pp. 7012-7029 ◽  
Author(s):  
Christopher W. Tsang ◽  
Michael Fedchyshyn ◽  
John Harrison ◽  
Hong Xie ◽  
Jing Xue ◽  
...  
Keyword(s):  
Synaptic Transmission ◽  
Synaptic Vesicle ◽  
Hippocampal Neurons ◽  
Neuronal Development ◽  
Synapse Formation ◽  
Vesicle Traffic ◽  
Axon Development ◽  
Central Synapses ◽  
Synaptic Vesicle Fusion

ABSTRACT The septin family of GTPases, first identified for their roles in cell division, are also expressed in postmitotic tissues. SEPT3 (G-septin) and SEPT5 (CDCrel-1) are highly expressed in neurons, enriched in presynaptic terminals, and associated with synaptic vesicles. These characteristics suggest that SEPT3 or SEPT5 might be important for synapse formation, maturation, or synaptic vesicle traffic. Since Sept5 −/− mice do not show any overt neurological phenotypes, we generated Sept3 −/− and Sept3 −/− Sept5 −/− mice and found that SEPT3 and SEPT5 are not essential for development, fertility, or viability. Changes in the expression of septins were noted in the absence of SEPT3, SEPT5, and both septins. SEPT5 association with other septins in brain tissue was unaffected by the removal of SEPT3. No abnormalities were observed in the gross morphology and synapses of the hippocampus. Similarly, axon development and synapse formation were unaffected in vitro. In cultured hippocampal neurons, the size of the recycling synaptic vesicle pool was unaltered in the absence of SEPT3. Furthermore, synaptic transmission at two different central synapses was not significantly affected in Sept3 −/− Sept5 −/− mice. These results indicate that SEPT3 and SEPT5 are dispensable for neuronal development as well as for synaptic vesicle fusion and recycling.

scholarly journals Identification of IL10RA by Weighted Correlation Network Analysis and in vitro Validation of Its Association With Prognosis of Metastatic Melanoma

2021 ◽  
Vol 8 ◽  
Author(s):  
Si Cheng ◽  
Zhe Li ◽  
Wenhao Zhang ◽  
Zhiqiang Sun ◽  
Zhigang Fan ◽  
...  
Keyword(s):  
Network Analysis ◽  
Metastatic Melanoma ◽  
Large Scale ◽  
Molecular Mechanisms ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Enrichment Analysis ◽  
Gene Set Enrichment Analysis ◽  
Migration And Invasion

Skin cutaneous melanoma (SKCM) is the major cause of death for skin cancer patients, its high metastasis often leads to poor prognosis of patients with malignant melanoma. However, the molecular mechanisms underlying metastatic melanoma remain to be elucidated. In this study we aim to identify and validate prognostic biomarkers associated with metastatic melanoma. We first construct a co-expression network using large-scale public gene expression profiles from GEO, from which candidate genes are screened out using weighted gene co-expression network analysis (WGCNA). A total of eight modules are established via the average linkage hierarchical clustering, and 111 hub genes are identified from the clinically significant modules. Next, two other datasets from GEO and TCGA are used for further screening of biomarker genes related to prognosis of metastatic melanoma, and identified 11 key genes via survival analysis. We find that IL10RA has the highest correlation with clinically important modules among all identified biomarker genes. Further in vitro biochemical experiments, including CCK8 assays, wound-healing assays and transwell assays, have verified that IL10RA can significantly inhibit the proliferation, migration and invasion of melanoma cells. Furthermore, gene set enrichment analysis shows that PI3K-AKT signaling pathway is significantly enriched in metastatic melanoma with highly expressed IL10RA, indicating that IL10RA mediates in metastatic melanoma via PI3K-AKT pathway.

scholarly journals Biophysical and biochemical properties of Deup1 self-assemblies: a potential driver for deuterosome formation during multiciliogenesis

Biology Open ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. bio056432 ◽  
Author(s):  
Shohei Yamamoto ◽  
Ryoichi Yabuki ◽  
Daiju Kitagawa
Keyword(s):  
Self Assembly ◽  
Large Scale ◽  
Molecular Mechanisms ◽  
Coiled Coil ◽  
Biochemical Properties ◽  
The Self ◽  
Centrosomal Protein ◽  
Biochemical Analyses ◽  
Stable Structures

ABSTRACTThe deuterosome is a non-membranous organelle involved in large-scale centriole amplification during multiciliogenesis. Deuterosomes are specifically assembled during the process of multiciliogenesis. However, the molecular mechanisms underlying deuterosome formation are poorly understood. In this study, we investigated the molecular properties of deuterosome protein 1 (Deup1), an essential protein involved in deuterosome assembly. We found that Deup1 has the ability to self-assemble into macromolecular condensates both in vitro and in cells. The Deup1-containing structures formed in multiciliogenesis and the Deup1 condensates self-assembled in vitro showed low turnover of Deup1, suggesting that Deup1 forms highly stable structures. Our biochemical analyses revealed that an increase of the concentration of Deup1 and a crowded molecular environment both facilitate Deup1 self-assembly. The self-assembly of Deup1 relies on its N-terminal region, which contains multiple coiled coil domains. Using an optogenetic approach, we demonstrated that self-assembly and the C-terminal half of Deup1 were sufficient to spatially compartmentalize centrosomal protein 152 (Cep152) and polo like kinase 4 (Plk4), master components for centriole biogenesis, in the cytoplasm. Collectively, the present data suggest that Deup1 forms the structural core of the deuterosome through self-assembly into stable macromolecular condensates.This article has an associated First Person interview with the first author of the paper.

scholarly journals From Zero to Neuro-Reprogramming: Innovations in Translational Neuroregenerative Medicine

2019 ◽  
Vol 9 (1) ◽  
pp. 54-60
Author(s):  
Ahmad Galuta ◽  
Eve Tsai
Keyword(s):  
Stem Cells ◽  
Nervous System ◽  
Large Scale ◽  
Neuronal Development ◽  
Developmental Stages ◽  
Study Patient ◽  
Patient Specific ◽  
Translational Study ◽  
Neuroregenerative Medicine

Acquiring live human nervous tissue for research presents ethical and technical constraints. As a result, clinicians and scientists resort to using animal models to investigate human neuronal development and degeneration. However, innate species differences in neurobiology have hindered the translation of disease pathologies and development of therapeutic strategies. The discovery of endogenous neural stem cells (NSCs) and their examination has been critical for neuronal development, degeneration and regeneration. NSCs can exist in different developmental stages, embryonic through adult, and possess the capacity to generate the various cells that make up the nervous system. Importantly, human somatic cells can be obtained non-invasively and genetically reprogrammed into NSCs providing an ethically viable source of stem cells for translational study and potential therapy. Novel methods to generate NSCs of various developmental origins and regional identities are rapidly evolving to provide safer, quicker, and more efficient reprogramming strategies. Reprogrammed NSCs share many molecular and functional attributes with their endogenous NSC counterparts and can be used for in vitro modelling at a large scale. The accessibility to study patient specific NSCs allows the causal inferences of human disease mechanisms that may be unfeasible to model in animals. Despite the novelty of this burgeoning field, the opportunity for translational discoveries in neuronal development and degeneration and for therapeutic applications is unprecedented. This review will highlight the advances in manufacturing NSCs and their translational implications for disease modelling and potential treatment of the nervous system.

scholarly journals Early Developmental Exposure to General Anesthetic Agents in Primary Neuron Culture Disrupts Synapse Formation via Actions on the mTOR Pathway

2018 ◽  
Author(s):  
Jing Xu ◽  
R. Paige Mathena ◽  
Michael Xu ◽  
YuChia Wang ◽  
CheJui Chang ◽  
...  
Keyword(s):  
Neuronal Development ◽  
Synapse Formation ◽  
Epidemiologic Studies ◽  
Mtor Pathway ◽  
General Anesthetic ◽  
Neuron Culture ◽  
Neurodevelopmental Disease ◽  
Anesthetic Agents ◽  
Pharmacologic Inhibition

Human epidemiologic studies and laboratory investigations in animal models suggest that exposure to general anesthetic agents (GAs) have harmful effects on brain development. The mechanism underlying this putative iatrogenic condition is not clear and there are currently no accepted strategies for prophylaxis or treatment. Recent evidence suggests that anesthetics might cause persistent deficits in synaptogenesis by disrupting key events in neurodevelopment. Using an in vitro model consisting of dissociated primary cultured mouse neurons we demonstrate abnormal pre- and post-synaptic marker expression after a clinically relevant isoflurane anesthesia exposure conducted during neuron development. We find that pharmacologic inhibition of the mechanistic target of rapamycin (mTOR) pathway can reverse the observed changes. Isoflurane exposure increases expression of phospho-S6, a marker of mTOR pathway activity, in a concentration-dependent fashion and this effect occurs throughout neuronal development. The mTOR 1 complex (mTORC1) and the mTOR 2 complex (mTORC2) branches of the pathway are both activated by isoflurane exposure and this is reversible with branch-specific inhibitors. Upregulation of mTOR is also seen with sevoflurane and propofol exposure, suggesting that this mechanism of developmental anesthetic neurotoxicity may occur with all the commonly used GAs in pediatric practice. We conclude that GAs disrupt the development of neurons during development by activating a well-defined neurodevelopmental disease pathway and that this phenotype can be reversed by pharmacologic inhibition.

scholarly journals The Interaction of TRAF6 With Neuroplastin Promotes Spinogenesis During Early Neuronal Development

2020 ◽  
Vol 8 ◽  
Author(s):  
Sampath Kumar Vemula ◽  
Ayse Malci ◽  
Lennart Junge ◽  
Anne-Christin Lehmann ◽  
Ramya Rama ◽  
...  
Keyword(s):  
Neuronal Development ◽  
Synapse Formation ◽  
Tumor Necrosis Factor Receptor ◽  
Physical Interaction ◽  
Binding Assays ◽  
C Terminus ◽  
Synapse Density ◽  
Pharmacological Blockade ◽  
Necrosis Factor

Correct brain wiring depends on reliable synapse formation. Nevertheless, signaling codes promoting synaptogenesis are not fully understood. Here, we report a spinogenic mechanism that operates during neuronal development and is based on the interaction of tumor necrosis factor receptor-associated factor 6 (TRAF6) with the synaptic cell adhesion molecule neuroplastin. The interaction between these proteins was predicted in silico and verified by co-immunoprecipitation in extracts from rat brain and co-transfected HEK cells. Binding assays show physical interaction between neuroplastin’s C-terminus and the TRAF-C domain of TRAF6 with a Kd value of 88 μM. As the two proteins co-localize in primordial dendritic protrusions, we used young cultures of rat and mouse as well as neuroplastin-deficient mouse neurons and showed with mutagenesis, knock-down, and pharmacological blockade that TRAF6 is required by neuroplastin to promote early spinogenesis during in vitro days 6-9, but not later. Time-framed TRAF6 blockade during days 6–9 reduced mEPSC amplitude, number of postsynaptic sites, synapse density and neuronal activity as neurons mature. Our data unravel a new molecular liaison that may emerge during a specific window of the neuronal development to determine excitatory synapse density in the rodent brain.

scholarly journals CloneSifter: enrichment of rare clones from heterogeneous cell populations

BMC Biology ◽  
2020 ◽  
Vol 18 (1) ◽  
Author(s):  
David Feldman ◽  
FuNien Tsai ◽  
Anthony J. Garrity ◽  
Ryan O’Rourke ◽  
Lisa Brenan ◽  
...  
Keyword(s):  
Large Scale ◽  
Molecular Mechanisms ◽  
Cancer Metastasis ◽  
Population Level ◽  
Fitness Assessment ◽  
Large Populations ◽  
Organismal Development ◽  
Insight Into

Abstract Background Many biological processes, such as cancer metastasis, organismal development, and acquisition of resistance to cytotoxic therapy, rely on the emergence of rare sub-clones from a larger population. Understanding how the genetic and epigenetic features of diverse clones affect clonal fitness provides insight into molecular mechanisms underlying selective processes. While large-scale barcoding with NGS readout has facilitated cellular fitness assessment at the population level, this approach does not support characterization of clones prior to selection. Single-cell genomics methods provide high biological resolution, but are challenging to scale across large populations to probe rare clones and are destructive, limiting further functional analysis of important clones. Results Here, we develop CloneSifter, a methodology for tracking and enriching rare clones throughout their response to selection. CloneSifter utilizes a CRISPR sgRNA-barcode library that facilitates the isolation of viable cells from specific clones within the barcoded population using a sequence-specific retrieval reporter. We demonstrate that CloneSifter can measure clonal fitness of cancer cell models in vitro and retrieve targeted clones at abundance as low as 1 in 1883 in a heterogeneous cell population. Conclusions CloneSifter provides a means to track and access specific and rare clones of interest across dynamic changes in population structure to comprehensively explore the basis of these changes.

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