RESUMEN
Lowe Syndrome (LS) is a rare X-linked disorder characterized by renal dysfunction, cataracts, and several central nervous system (CNS) anomalies. The mechanisms underlying the neurological dysfunction in LS remain unclear, albeit they share some phenotypic characteristics similar to the deficiency or dysfunction of the Reelin signaling, a relevant pathway with roles in CNS development and neuronal functions. In this study, we investigated the role of OCRL1, an inositol polyphosphate 5-phosphatase encoded by the OCRL gene, mutated in LS, focusing on its impact on endosomal trafficking and receptor recycling in human neuronal cells. Specifically, we tested the effects of OCRL1 deficiency in the trafficking and signaling of ApoER2/LRP8, a receptor for the ligand Reelin. We found that loss of OCRL1 impairs ApoER2 intracellular trafficking, leading to reduced receptor expression and decreased levels at the plasma membrane. Additionally, human neurons deficient in OCRL1 showed impairments in ApoER2/Reelin-induced responses. Our findings highlight the critical role of OCRL1 in regulating ApoER2 endosomal recycling and its impact on the ApoER2/Reelin signaling pathway, providing insights into potential mechanisms underlying the neurological manifestations of LS.
Asunto(s)
Moléculas de Adhesión Celular Neuronal , Endosomas , Proteínas de la Matriz Extracelular , Proteínas Relacionadas con Receptor de LDL , Proteínas del Tejido Nervioso , Neuronas , Monoéster Fosfórico Hidrolasas , Transporte de Proteínas , Proteína Reelina , Serina Endopeptidasas , Humanos , Monoéster Fosfórico Hidrolasas/metabolismo , Monoéster Fosfórico Hidrolasas/genética , Monoéster Fosfórico Hidrolasas/deficiencia , Proteínas del Tejido Nervioso/metabolismo , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/deficiencia , Serina Endopeptidasas/metabolismo , Serina Endopeptidasas/genética , Serina Endopeptidasas/deficiencia , Moléculas de Adhesión Celular Neuronal/metabolismo , Moléculas de Adhesión Celular Neuronal/genética , Moléculas de Adhesión Celular Neuronal/deficiencia , Proteínas de la Matriz Extracelular/metabolismo , Proteínas de la Matriz Extracelular/genética , Proteínas de la Matriz Extracelular/deficiencia , Endosomas/metabolismo , Neuronas/metabolismo , Proteínas Relacionadas con Receptor de LDL/metabolismo , Proteínas Relacionadas con Receptor de LDL/genética , Transducción de Señal , Síndrome Oculocerebrorrenal/genética , Síndrome Oculocerebrorrenal/metabolismoRESUMEN
BACKGROUND AND OBJECTIVES: Anti-IgLON5 disease is an autoimmune neurodegenerative disorder characterized by various phenotypes, notably sleep and movement disorders and tau pathology. Although the disease is known to be associated with the neuronal cell adhesion protein IgLON5, the physiologic function of IgLON5 remains elusive. There are conflicting views on whether autoantibodies cause loss of function, activation of IgLON5, or inflammation-associated neuronal damage, ultimately leading to the disease. We generated IgLON5 knockout (-/-) mice to investigate the functions of IgLON5 and elucidate the pathomechanism of anti-IgLON5 disease. METHODS: IgLON5 knockout (-/-) mice underwent behavioral tests investigating motor function, psychiatric function (notably anxiety and depression), social and exploratory behaviors, spatial learning and memory, and sensory perception. Histologic analysis was conducted to investigate tau aggregation in mice with tauopathy. RESULTS: IgLON5-/- mice had poorer performance in the wire hang and rotarod tests (which are tests for motor function) than wild-type mice. Moreover, IgLON5-/- mice exhibited decreased anxiety-like behavior and/or hyperactivity in behavior tests, including light/dark transition test and open field test. IgLON5-/- mice also exhibited poorer remote memory in the contextual fear conditioning test. However, neither sleeping disabilities assessed by EEG nor tau aggregation was detected in the knockout mice. DISCUSSION: These results suggest that IgLON5 is associated with activity, anxiety, motor ability, and contextual fear memory. Comparing the various phenotypes of anti-IgLON5 disease, anti-IgLON5 disease might partially be associated with loss of function of IgLON5; however, other phenotypes, such as sleep disorders and tau aggregation, can be caused by gain of function of IgLON5 and/or neuronal damage due to inflammation. Further studies are needed to elucidate the role of IgLON5 in the pathogenesis of anti-IgLON5 diseases.
Asunto(s)
Moléculas de Adhesión Celular Neuronal , Ratones Noqueados , Fenotipo , Animales , Masculino , Ratones , Ansiedad/inmunología , Autoanticuerpos/sangre , Conducta Animal/fisiología , Moléculas de Adhesión Celular Neuronal/deficiencia , Modelos Animales de Enfermedad , Ratones Endogámicos C57BL , Tauopatías/fisiopatología , Tauopatías/inmunología , HumanosRESUMEN
Plasma membrane rupture (PMR) in dying cells undergoing pyroptosis or apoptosis requires the cell-surface protein NINJ11. PMR releases pro-inflammatory cytoplasmic molecules, collectively called damage-associated molecular patterns (DAMPs), that activate immune cells. Therefore, inhibiting NINJ1 and PMR may limit the inflammation that is associated with excessive cell death. Here we describe an anti-NINJ1 monoclonal antibody that specifically targets mouse NINJ1 and blocks oligomerization of NINJ1, preventing PMR. Electron microscopy studies showed that this antibody prevents NINJ1 from forming oligomeric filaments. In mice, inhibition of NINJ1 or Ninj1 deficiency ameliorated hepatocellular PMR induced with TNF plus D-galactosamine, concanavalin A, Jo2 anti-Fas agonist antibody or ischaemia-reperfusion injury. Accordingly, serum levels of lactate dehydrogenase, the liver enzymes alanine aminotransaminase and aspartate aminotransferase, and the DAMPs interleukin 18 and HMGB1 were reduced. Moreover, in the liver ischaemia-reperfusion injury model, there was an attendant reduction in neutrophil infiltration. These data indicate that NINJ1 mediates PMR and inflammation in diseases driven by aberrant hepatocellular death.
Asunto(s)
Anticuerpos Monoclonales , Membrana Celular , Inflamación , Hígado , Factores de Crecimiento Nervioso , Daño por Reperfusión , Animales , Ratones , Alanina Transaminasa , Alarminas , Anticuerpos Monoclonales/inmunología , Aspartato Aminotransferasas , Moléculas de Adhesión Celular Neuronal/antagonistas & inhibidores , Moléculas de Adhesión Celular Neuronal/deficiencia , Moléculas de Adhesión Celular Neuronal/inmunología , Moléculas de Adhesión Celular Neuronal/ultraestructura , Muerte Celular , Membrana Celular/patología , Membrana Celular/ultraestructura , Concanavalina A , Galactosamina , Hepatocitos/patología , Hepatocitos/ultraestructura , Inflamación/patología , Lactato Deshidrogenasas , Hígado/patología , Microscopía Electrónica , Factores de Crecimiento Nervioso/antagonistas & inhibidores , Factores de Crecimiento Nervioso/deficiencia , Factores de Crecimiento Nervioso/inmunología , Factores de Crecimiento Nervioso/ultraestructura , Infiltración Neutrófila , Daño por Reperfusión/patologíaRESUMEN
The chemical synapse is one type of cell-adhesion system that transmits information from a neuron to another neuron in the complex neuronal network in the brain. Synaptic transmission is the rate-limiting step during the information processing in the neuronal network and its plasticity is involved in cognitive functions. Thus, morphological and electrophysiological analyses of synapses are of particular importance in neuroscience research. In the current study, we applied super-resolved three-dimensional stimulated emission depletion (3D-STED) microscopy for the morphological analyses of synapses. This approach allowed us to estimate the precise number of excitatory and inhibitory synapses in the mouse hippocampal tissue. We discovered a region-specific increase in excitatory synapses in a model mouse of autism spectrum disorder, Neuroligin-3 KO, with this method. This type of analysis will open a new field in developmental neuroscience in the future.
Asunto(s)
Trastorno del Espectro Autista/genética , Región CA1 Hipocampal/metabolismo , Moléculas de Adhesión Celular Neuronal/genética , Proteínas de la Membrana/genética , Microscopía/métodos , Proteínas del Tejido Nervioso/genética , Neuronas/metabolismo , Sinapsis/genética , Animales , Trastorno del Espectro Autista/diagnóstico por imagen , Trastorno del Espectro Autista/metabolismo , Trastorno del Espectro Autista/patología , Región CA1 Hipocampal/diagnóstico por imagen , Región CA1 Hipocampal/patología , Moléculas de Adhesión Celular Neuronal/deficiencia , Cognición/fisiología , Modelos Animales de Enfermedad , Técnicas de Inactivación de Genes , Proteínas de Andamiaje Homer/genética , Proteínas de Andamiaje Homer/metabolismo , Masculino , Proteínas de la Membrana/deficiencia , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Microscopía/instrumentación , Proteínas del Tejido Nervioso/deficiencia , Neuroimagen/instrumentación , Neuroimagen/métodos , Neuronas/patología , Sinapsis/metabolismo , Sinapsis/ultraestructura , Transmisión Sináptica/fisiologíaRESUMEN
Reelin is a large secreted glycoprotein that regulates neuronal migration, lamination and establishment of dendritic architecture in the embryonic brain. Reelin expression switches postnatally from Cajal-Retzius cells to interneurons. However, reelin function in interneuron development is still poorly understood. Here, we have investigated the role of reelin in interneuron development in the postnatal neocortex. To preclude early cortical migration defects caused by reelin deficiency, we employed a conditional reelin knockout (RelncKO) mouse to induce postnatal reelin deficiency. Induced reelin deficiency caused dendritic hypertrophy in distal dendritic segments of neuropeptide Y-positive (NPY+) and calretinin-positive (Calr+) interneurons, and in proximal dendritic segments of parvalbumin-positive (Parv+) interneurons. Chronic recombinant Reelin treatment rescued dendritic hypertrophy in Relncko interneurons. Moreover, we provide evidence that RelncKO interneuron hypertrophy is due to presynaptic GABABR dysfunction. Thus, GABABRs in RelncKO interneurons were unable to block N-type (Cav2.2) Ca2+ channels that control neurotransmitter release. Consequently, the excessive Ca2+ influx through AMPA receptors, but not NMDA receptors, caused interneuron dendritic hypertrophy. These findings suggest that reelin acts as a 'stop-growth-signal' for postnatal interneuron maturation.
Asunto(s)
Moléculas de Adhesión Celular Neuronal/metabolismo , Dendritas/metabolismo , Proteínas de la Matriz Extracelular/metabolismo , Interneuronas/citología , Neocórtex/crecimiento & desarrollo , Proteínas del Tejido Nervioso/metabolismo , Serina Endopeptidasas/metabolismo , Animales , Calbindina 2/metabolismo , Calcio/metabolismo , Moléculas de Adhesión Celular Neuronal/deficiencia , Moléculas de Adhesión Celular Neuronal/farmacología , Dendritas/efectos de los fármacos , Proteínas de la Matriz Extracelular/deficiencia , Proteínas de la Matriz Extracelular/farmacología , Hipertrofia , Interneuronas/efectos de los fármacos , Interneuronas/metabolismo , Ratones , Ratones Noqueados , Neocórtex/citología , Neocórtex/efectos de los fármacos , Neocórtex/patología , Proteínas del Tejido Nervioso/deficiencia , Proteínas del Tejido Nervioso/farmacología , Neuropéptido Y/metabolismo , Parvalbúminas/metabolismo , Receptores de GABA-B/metabolismo , Receptores de Glutamato/metabolismo , Proteína Reelina , Serina Endopeptidasas/deficiencia , Serina Endopeptidasas/farmacologíaRESUMEN
Neurons have recently emerged as essential cellular constituents of the tumour microenvironment, and their activity has been shown to increase the growth of a diverse number of solid tumours1. Although the role of neurons in tumour progression has previously been demonstrated2, the importance of neuronal activity to tumour initiation is less clear-particularly in the setting of cancer predisposition syndromes. Fifteen per cent of individuals with the neurofibromatosis 1 (NF1) cancer predisposition syndrome (in which tumours arise in close association with nerves) develop low-grade neoplasms of the optic pathway (known as optic pathway gliomas (OPGs)) during early childhood3,4, raising the possibility that postnatal light-induced activity of the optic nerve drives tumour initiation. Here we use an authenticated mouse model of OPG driven by mutations in the neurofibromatosis 1 tumour suppressor gene (Nf1)5 to demonstrate that stimulation of optic nerve activity increases optic glioma growth, and that decreasing visual experience via light deprivation prevents tumour formation and maintenance. We show that the initiation of Nf1-driven OPGs (Nf1-OPGs) depends on visual experience during a developmental period in which Nf1-mutant mice are susceptible to tumorigenesis. Germline Nf1 mutation in retinal neurons results in aberrantly increased shedding of neuroligin 3 (NLGN3) within the optic nerve in response to retinal neuronal activity. Moreover, genetic Nlgn3 loss or pharmacological inhibition of NLGN3 shedding blocks the formation and progression of Nf1-OPGs. Collectively, our studies establish an obligate role for neuronal activity in the development of some types of brain tumours, elucidate a therapeutic strategy to reduce OPG incidence or mitigate tumour progression, and underscore the role of Nf1mutation-mediated dysregulation of neuronal signalling pathways in mouse models of the NF1 cancer predisposition syndrome.
Asunto(s)
Transformación Celular Neoplásica/genética , Genes de Neurofibromatosis 1 , Mutación , Neurofibromina 1/genética , Neuronas/metabolismo , Glioma del Nervio Óptico/genética , Glioma del Nervio Óptico/patología , Animales , Astrocitoma/genética , Astrocitoma/patología , Moléculas de Adhesión Celular Neuronal/deficiencia , Moléculas de Adhesión Celular Neuronal/genética , Moléculas de Adhesión Celular Neuronal/metabolismo , Transformación Celular Neoplásica/efectos de la radiación , Femenino , Mutación de Línea Germinal , Humanos , Masculino , Proteínas de la Membrana/deficiencia , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Proteínas del Tejido Nervioso/deficiencia , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Neuronas/efectos de la radiación , Nervio Óptico/citología , Nervio Óptico/efectos de la radiación , Estimulación Luminosa , Retina/citología , Retina/efectos de la radiaciónRESUMEN
Homozygous Dab1 yotari mutant mice, Dab1yot (yot/yot) mice, have an autosomal recessive mutation of Dab1 and show reeler-like phenotype including histological abnormality of the cerebellum, hippocampus, and cerebral cortex. We here show abnormal hippocampal development of yot/yot mice where granule cells and pyramidal cells fail to form orderly rows but are dispersed diffusely in vague multiplicative layers. Possibly due to the positioning failure of granule cells and pyramidal cells and insufficient synaptogenesis, axons of the granule cells did not extend purposefully to connect with neighboring regions in yot/yot mice. We found that both hippocampal granule cells and pyramidal cells of yot/yot mice expressed proteins reactive with the anti-Dab1 antibody. We found that Y198- phosphorylated Dab1 of yot/yot mice was greatly decreased. Accordingly the downstream molecule, Akt was hardly phosphorylated. Especially, synapse formation was defective and the distribution of neurons was scattered in hippocampus of yot/yot mice. Some of neural cell adhesion molecules and hippocampus associated transcription factors of the neurons were expressed aberrantly, suggesting that the Reelin-Dab1 signaling pathway seemed to be importantly involved in not only neural migration as having been shown previously but also neural maturation and/or synaptogenesis of the mice. It is interesting to clarify whether the defective neural maturation is a direct consequence of the dysfunctional Dab1, or alternatively secondarily due to the Reelin-Dab1 intracellular signaling pathways.
Asunto(s)
Moléculas de Adhesión Celular Neuronal/fisiología , Proteínas de la Matriz Extracelular/fisiología , Hipocampo/anomalías , Ratones Mutantes/anomalías , Proteínas del Tejido Nervioso/fisiología , Serina Endopeptidasas/fisiología , Transducción de Señal/fisiología , Animales , Moléculas de Adhesión Celular Neuronal/deficiencia , Movimiento Celular , Activación Enzimática , Proteínas de la Matriz Extracelular/deficiencia , Genes Recesivos , Hipocampo/embriología , Hipocampo/metabolismo , Hipocampo/patología , Homocigoto , Ratones , Ratones Mutantes/genética , Ratones Mutantes/metabolismo , Proteínas del Tejido Nervioso/biosíntesis , Proteínas del Tejido Nervioso/deficiencia , Proteínas del Tejido Nervioso/genética , Moléculas de Adhesión de Célula Nerviosa/biosíntesis , Moléculas de Adhesión de Célula Nerviosa/genética , Fenotipo , Fosforilación , Procesamiento Proteico-Postraduccional , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteína Reelina , Serina Endopeptidasas/deficiencia , Sinapsis/metabolismo , Factores de Transcripción/biosíntesis , Factores de Transcripción/genéticaRESUMEN
Clever-1 also known as Stabilin-1 and FEEL-1 is a scavenger molecule expressed on a subpopulation of anti-inflammatory macrophages and lymphatic endothelial cells (LECs). However, its role in regulating dendritic cell (DC) trafficking and subsequent effects on immunity have remained unexplored. In this study, we demonstrate that DC trafficking from the skin into the draining lymph nodes is compromised in the absence of Clever-1. By adoptive transfer approaches we further show that the poor trafficking is due to the impaired entrance of DCs into afferent lymphatics. Despite this, injections of ovalbumin-loaded DCs into the footpads induced a stronger proliferative response of OT II T cells in the draining lymph nodes. This could be explained by the increased MHC II expression on DCs and a less tolerogenic phenotype of LECs in lymph nodes of Clever-1 knockout mice. Thus, although fewer DCs reach the nodes, they are more active in creating antigen-specific immune responses. This suggests that the DCs migrating to the draining lymph node within Clever-1 positive lymphatics experience immunosuppressive interactions with LECs. In conclusion, besides being a trafficking molecule on lymphatic vasculature Clever-1 is immunosuppressive towards migrating DCs and thus, regulates the magnitude of immune responses created by incoming DCs in the draining lymph nodes.
Asunto(s)
Moléculas de Adhesión Celular Neuronal/deficiencia , Células Dendríticas/inmunología , Células Endoteliales/inmunología , Eliminación de Gen , Migración Transendotelial y Transepitelial/inmunología , Animales , Moléculas de Adhesión Celular Neuronal/inmunología , Células Dendríticas/citología , Células Endoteliales/citología , Ratones , Ratones Noqueados , Migración Transendotelial y Transepitelial/genéticaRESUMEN
[Figure: see text].
Asunto(s)
Anticuerpos Neutralizantes/farmacología , Aterosclerosis/prevención & control , Moléculas de Adhesión Celular Neuronal/antagonistas & inhibidores , Adhesión Celular/efectos de los fármacos , Células Endoteliales/efectos de los fármacos , Proteínas de la Matriz Extracelular/antagonistas & inhibidores , Rodamiento de Leucocito/efectos de los fármacos , Leucocitos/efectos de los fármacos , Proteínas del Tejido Nervioso/antagonistas & inhibidores , Oligonucleótidos Antisentido/farmacología , Animales , Aterosclerosis/genética , Aterosclerosis/inmunología , Aterosclerosis/metabolismo , Receptor 1 de Quimiocinas CX3C/genética , Moléculas de Adhesión Celular Neuronal/deficiencia , Moléculas de Adhesión Celular Neuronal/genética , Técnicas de Cocultivo , Modelos Animales de Enfermedad , Células Endoteliales/inmunología , Células Endoteliales/metabolismo , Proteínas de la Matriz Extracelular/deficiencia , Proteínas de la Matriz Extracelular/genética , Femenino , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Humanos , Proteínas Relacionadas con Receptor de LDL/metabolismo , Leucocitos/inmunología , Leucocitos/metabolismo , Masculino , Ratones Transgénicos , Proteínas del Tejido Nervioso/deficiencia , Proteínas del Tejido Nervioso/genética , Placa Aterosclerótica , Receptores de LDL/deficiencia , Receptores de LDL/genética , Proteína Reelina , Serina Endopeptidasas/deficiencia , Serina Endopeptidasas/genética , Transducción de Señal , Células U937RESUMEN
Reelin, an extracellular matrix protein, is secreted by Cajal-Retzius cells and plays crucial roles in the development of brain structures and neuronal functions. Reductions in Reelin cause the brain dysfunctions associated with mental disorders, such as schizophrenia. A recent genome-wide copy number variation analysis of Japanese schizophrenia patients identified a novel deletion in RELN encoding Reelin. To clarify the pathophysiological role of the RELN deletion, we developed transgenic mice carrying the RELN deletion (Reln-del) and found abnormalities in their brain structures and social behavior. In the present study, we performed an in vitro analysis of Reelin expression, intracellular Reelin signaling, and the morphology of primary cultured cortical neurons from wild-type (WT) and Reln-del mice. Reelin protein levels were lower in Reln-del neurons than in WT neurons. Dab1 expression levels were significantly higher in Reln-del neurons than in WT neurons, suggesting that Reelin signaling was decreased in Reln-del neurons. Reelin was mainly expressed in γ-aminobutyric acid (GABA)-ergic inhibitory neurons, but not in parvalbumin (PV)-positive neurons. A small proportion of Ca2+/calmodulin-dependent protein kinase II α subunit (CaMKIIα)-positive excitatory neurons also expressed Reelin. In comparisons with WT neurons, significant decreases were observed in neurite lengths and branch points as well as in the number of postsynaptic density protein 95 (PSD95) immunoreactive puncta in Reln-del neurons. A disintegrin and metalloproteinase with thrombospondin motifs-3 (ADAMTS-3) is a protease that inactivates Reelin by cleavage at the N-t site. The knockdown of ADAMTS-3 by short hairpin RNAs suppressed Reelin cleavage in conditioned medium and reduced Dab1 expression, indicating that Reelin signaling was enhanced in the primary cultured cortical neurons of WT and heterozygous Reln-del. Accordingly, the inhibition of ADAMTS-3 may be a potential candidate in the clinical treatment of schizophrenia by enhancing Reelin signaling in the brain.
Asunto(s)
Moléculas de Adhesión Celular Neuronal/deficiencia , Corteza Cerebral/metabolismo , Proteínas de la Matriz Extracelular/deficiencia , Eliminación de Gen , Proteínas del Tejido Nervioso/deficiencia , Neuronas/metabolismo , Esquizofrenia/metabolismo , Serina Endopeptidasas/deficiencia , Animales , Moléculas de Adhesión Celular Neuronal/biosíntesis , Moléculas de Adhesión Celular Neuronal/genética , Células Cultivadas , Corteza Cerebral/citología , Proteínas de la Matriz Extracelular/biosíntesis , Proteínas de la Matriz Extracelular/genética , Células HEK293 , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Proteínas del Tejido Nervioso/biosíntesis , Proteínas del Tejido Nervioso/genética , Proteína Reelina , Esquizofrenia/genética , Serina Endopeptidasas/biosíntesis , Serina Endopeptidasas/genética , Transducción de Señal/fisiologíaRESUMEN
Reelin is a protein that is best known for its role in controlling neuronal layer formation in the developing cortex. Here, we studied its role for post-natal cortical network function, which is poorly explored. To preclude early cortical migration defects caused by Reelin deficiency, we used a conditional Reelin knock-out (RelncKO ) mouse, and induced Reelin deficiency post-natally. Induced Reelin deficiency caused hyperexcitability of the neocortical network in vitro and ex vivo. Blocking Reelin binding to its receptors ApoER2 and VLDLR resulted in a similar effect. Hyperexcitability in RelncKO organotypic slice cultures could be rescued by co-culture with wild-type organotypic slice cultures. Moreover, the GABAB receptor (GABAB R) agonist baclofen failed to activate and the antagonist CGP35348 failed to block GABAB Rs in RelncKO mice. Immunolabeling of RelncKO cortical slices revealed a reduction in GABAB R1 and GABAB R2 surface expression at the plasma membrane and western blot of RelncKO cortical tissue revealed decreased phosphorylation of the GABAB R2 subunit at serine 892 and increased phosphorylation at serine 783, reflecting receptor deactivation and proteolysis. These data show a role of Reelin in controlling early network activity, by modulating GABAB R function. Cover Image for this issue: https://doi.org/10.1111/jnc.15054.
Asunto(s)
Moléculas de Adhesión Celular Neuronal/deficiencia , Proteínas de la Matriz Extracelular/deficiencia , Neocórtex/metabolismo , Proteínas del Tejido Nervioso/deficiencia , Receptores de GABA-B/fisiología , Serina Endopeptidasas/deficiencia , Transducción de Señal/fisiología , Animales , Animales Recién Nacidos , Moléculas de Adhesión Celular Neuronal/genética , Proteínas de la Matriz Extracelular/genética , Femenino , Agonistas de Receptores GABA-B/farmacología , Masculino , Ratones , Ratones Noqueados , Proteínas del Tejido Nervioso/genética , Técnicas de Cultivo de Órganos , Proteína Reelina , Serina Endopeptidasas/genética , Transducción de Señal/efectos de los fármacosRESUMEN
The Class H scavenger receptors Stabilin-1 (Stab1) and Stabilin-2 (Stab2) are two of the most highly expressed genes in liver sinusoidal endothelial cells (LSECs). While Stab1-deficient (Stab1KO) and Stab2-deficient (Stab2KO) mice are phenotypically unremarkable, Stab1/2-double-deficient (StabDKO) mice exhibit perisinusoidal liver fibrosis, glomerulofibrotic nephropathy and a reduced life expectancy. These conditions are caused by insufficiently scavenged circulating noxious blood factors. The effects of either Stab-single- or double-deficiency on LSEC differentiation and function, however, have not yet been thoroughly investigated. Therefore, we performed comprehensive transcriptomic analyses of primary LSECs from Stab1KO, Stab2KO and StabDKO mice. Microarray analysis revealed dysregulation of pathways and genes involved in established LSEC functions while sinusoidal endothelial marker gene expression was grossly unchanged. 82 genes were significantly altered in Stab1KO, 96 genes in Stab2KO and 238 genes in StabDKO compared with controls; 42 genes were found to be commonly dysregulated in all three groups and all of these genes were downregulated. These commonly downregulated genes (CDGs) were categorized as "potential scavengers," "cell adhesion molecules," "TGF-ß/BMP-signaling" or "collagen and extracellular matrix (ECM) components". Among CDGs, Colec10, Lumican and Decorin, were the most strongly down-regulated genes and the corresponding proteins impact on the interaction of LSECs with chemokines, ECM components and carbohydrate structures. Similarly, "chemokine signaling," "cytokine-cytokine receptor interaction" and "ECM-receptor interaction," were the GSEA categories which represented most of the downregulated genes in Stab1KO and Stab2KO LSECs. In summary, our data show that loss of a single Stabilin scavenger receptor - and to a greater extent of both receptors - profoundly alters the transcriptomic repertoire of LSECs. These alterations may affect LSEC-specific functions, especially interactions of LSECs with the ECM and during inflammation as well as clearance of the peripheral blood.
Asunto(s)
Moléculas de Adhesión Celular Neuronal/genética , Células Endoteliales/metabolismo , Regulación de la Expresión Génica/genética , Cirrosis Hepática/genética , Animales , Moléculas de Adhesión Celular Neuronal/deficiencia , Quimiocinas/metabolismo , Perfilación de la Expresión Génica , Hígado/citología , Hígado/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Transcriptoma/genéticaRESUMEN
How developing and growing organisms attain their proper shape is a central problem of developmental biology. In this review, we investigate this question with respect to how the body axis and spine form in their characteristic linear head-to-tail fashion in vertebrates. Recent work in the zebrafish has implicated motile cilia and cerebrospinal fluid flow in axial morphogenesis and spinal straightness. We begin by introducing motile cilia, the fluid flows they generate and their roles in zebrafish development and growth. We then describe how cilia control body and spine shape through sensory cells in the spinal canal, a thread-like extracellular structure called the Reissner fiber, and expression of neuropeptide signals. Last, we discuss zebrafish mutants in which spinal straightness breaks down and three-dimensional curves form. These curves resemble the common but little-understood human disease Idiopathic Scoliosis. Zebrafish research is therefore poised to make progress in our understanding of this condition and, more generally, how body and spine shape is acquired and maintained through development and growth.
Asunto(s)
Moléculas de Adhesión Celular Neuronal/genética , Cilios/metabolismo , Proteínas del Citoesqueleto/genética , Morfogénesis/genética , Escoliosis/genética , Columna Vertebral/metabolismo , Proteínas de Pez Cebra/genética , Animales , Axonema/metabolismo , Axonema/ultraestructura , Moléculas de Adhesión Celular Neuronal/deficiencia , Líquido Cefalorraquídeo/química , Cilios/patología , Cilios/ultraestructura , Proteínas del Citoesqueleto/deficiencia , Modelos Animales de Enfermedad , Embrión no Mamífero , Regulación del Desarrollo de la Expresión Génica , Humanos , Mutación , Escoliosis/metabolismo , Escoliosis/patología , Transducción de Señal , Columna Vertebral/anomalías , Columna Vertebral/crecimiento & desarrollo , Urotensinas/genética , Pez Cebra , Proteínas de Pez Cebra/deficienciaRESUMEN
Recent studies have suggested that lymphatics help to restore heart function after cardiac injury1-6. Here we report that lymphatics promote cardiac growth, repair and cardioprotection in mice. We show that a lymphoangiocrine signal produced by lymphatic endothelial cells (LECs) controls the proliferation and survival of cardiomyocytes during heart development, improves neonatal cardiac regeneration and is cardioprotective after myocardial infarction. Embryos that lack LECs develop smaller hearts as a consequence of reduced cardiomyocyte proliferation and increased cardiomyocyte apoptosis. Culturing primary mouse cardiomyocytes in LEC-conditioned medium increases cardiomyocyte proliferation and survival, which indicates that LECs produce lymphoangiocrine signals that control cardiomyocyte homeostasis. Characterization of the LEC secretome identified the extracellular protein reelin (RELN) as a key component of this process. Moreover, we report that LEC-specific Reln-null mouse embryos develop smaller hearts, that RELN is required for efficient heart repair and function after neonatal myocardial infarction, and that cardiac delivery of RELN using collagen patches improves heart function in adult mice after myocardial infarction by a cardioprotective effect. These results highlight a lymphoangiocrine role of LECs during cardiac development and injury response, and identify RELN as an important mediator of this function.
Asunto(s)
Corazón/embriología , Sistema Linfático/citología , Sistema Linfático/metabolismo , Miocardio/citología , Miocitos Cardíacos/citología , Regeneración , Transducción de Señal , Animales , Animales Recién Nacidos , Apoptosis , Moléculas de Adhesión Celular Neuronal/deficiencia , Moléculas de Adhesión Celular Neuronal/genética , Moléculas de Adhesión Celular Neuronal/metabolismo , Proliferación Celular , Supervivencia Celular , Células Cultivadas , Células Endoteliales/metabolismo , Proteínas de la Matriz Extracelular/deficiencia , Proteínas de la Matriz Extracelular/genética , Proteínas de la Matriz Extracelular/metabolismo , Femenino , Humanos , Integrina beta1/metabolismo , Ratones , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Miocitos Cardíacos/metabolismo , Proteínas del Tejido Nervioso/deficiencia , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Tamaño de los Órganos , Organogénesis , Proteína Reelina , Serina Endopeptidasas/deficiencia , Serina Endopeptidasas/genética , Serina Endopeptidasas/metabolismoRESUMEN
A fundamental challenge in developing treatments for autism spectrum disorders is the heterogeneity of the condition. More than one hundred genetic mutations confer high risk for autism, with each individual mutation accounting for only a small fraction of cases1-3. Subsets of risk genes can be grouped into functionally related pathways, most prominently those involving synaptic proteins, translational regulation, and chromatin modifications. To attempt to minimize this genetic complexity, recent therapeutic strategies have focused on the neuropeptides oxytocin and vasopressin4-6, which regulate aspects of social behaviour in mammals7. However, it is unclear whether genetic risk factors predispose individuals to autism as a result of modifications to oxytocinergic signalling. Here we report that an autism-associated mutation in the synaptic adhesion molecule Nlgn3 results in impaired oxytocin signalling in dopaminergic neurons and in altered behavioural responses to social novelty tests in mice. Notably, loss of Nlgn3 is accompanied by a disruption of translation homeostasis in the ventral tegmental area. Treatment of Nlgn3-knockout mice with a new, highly specific, brain-penetrant inhibitor of MAP kinase-interacting kinases resets the translation of mRNA and restores oxytocin signalling and social novelty responses. Thus, this work identifies a convergence between the genetic autism risk factor Nlgn3, regulation of translation, and oxytocinergic signalling. Focusing on such common core plasticity elements might provide a pragmatic approach to overcoming the heterogeneity of autism. Ultimately, this would enable mechanism-based stratification of patient populations to increase the success of therapeutic interventions.
Asunto(s)
Trastorno Autístico/metabolismo , Trastorno Autístico/psicología , Modelos Animales de Enfermedad , Oxitocina/metabolismo , Conducta Social , Animales , Moléculas de Adhesión Celular Neuronal/deficiencia , Moléculas de Adhesión Celular Neuronal/genética , Factor 4E Eucariótico de Iniciación/metabolismo , Masculino , Proteínas de la Membrana/deficiencia , Proteínas de la Membrana/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Proteínas del Tejido Nervioso/deficiencia , Proteínas del Tejido Nervioso/genética , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Fosforilación/efectos de los fármacos , Biosíntesis de Proteínas/efectos de los fármacos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Transducción de Señal/efectos de los fármacos , Área Tegmental Ventral/citología , Área Tegmental Ventral/efectos de los fármacosRESUMEN
OBJECTIVE: Reelin, a secreted glycoprotein, was originally identified in the central nervous system, where it plays an important role in brain development and maintenance. In the cardiovascular system, reelin plays a role in atherosclerosis by enhancing vascular inflammation and in arterial thrombosis by promoting platelet adhesion, activation, and thrombus formation via APP (amyloid precursor protein) and GP (glycoprotein) Ib. However, the role of reelin in hemostasis and arterial thrombosis is not fully understood to date. Approach and Results: In the present study, we analyzed the importance of reelin for cytoskeletal reorganization of platelets and thrombus formation in more detail. Platelets release reelin to amplify alphaIIb beta3 integrin outside-in signaling by promoting platelet adhesion, cytoskeletal reorganization, and clot retraction via activation of Rho GTPases RAC1 (Ras-related C3 botulinum toxin substrate) and RhoA (Ras homolog family member A). Reelin interacts with the collagen receptor GP (glycoprotein) VI with subnanomolar affinity, induces tyrosine phosphorylation in a GPVI-dependent manner, and supports platelet binding to collagen and GPVI-dependent RAC1 activation, PLC gamma 2 (1-phosphatidylinositol-4,5-bisphosphate phosphodiesterase gamma-2) phosphorylation, platelet activation, and aggregation. When GPVI was deleted from the platelet surface by antibody treatment in reelin-deficient mice, thrombus formation was completely abolished after injury of the carotid artery while being only reduced in either GPVI-depleted or reelin-deficient mice. CONCLUSIONS: Our study identified a novel signaling pathway that involves reelin-induced GPVI activation and alphaIIb beta3 integrin outside-in signaling in platelets. Loss of both, GPVI and reelin, completely prevents stable arterial thrombus formation in vivo suggesting that inhibiting reelin-platelet-interaction might represent a novel strategy to avoid arterial thrombosis in cardiovascular disease.
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Plaquetas/enzimología , Traumatismos de las Arterias Carótidas/enzimología , Moléculas de Adhesión Celular Neuronal/sangre , Proteínas de la Matriz Extracelular/sangre , Proteínas del Tejido Nervioso/sangre , Neuropéptidos/sangre , Fosfolipasa C gamma/sangre , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/metabolismo , Glicoproteínas de Membrana Plaquetaria/metabolismo , Serina Endopeptidasas/sangre , Trombosis/enzimología , Proteína de Unión al GTP rac1/sangre , Proteína de Unión al GTP rhoA/sangre , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animales , Coagulación Sanguínea , Traumatismos de las Arterias Carótidas/sangre , Traumatismos de las Arterias Carótidas/etiología , Moléculas de Adhesión Celular Neuronal/deficiencia , Moléculas de Adhesión Celular Neuronal/genética , Retracción del Coagulo , Citoesqueleto/enzimología , Modelos Animales de Enfermedad , Proteínas de la Matriz Extracelular/deficiencia , Proteínas de la Matriz Extracelular/genética , Ratones de la Cepa 129 , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Proteínas del Tejido Nervioso/deficiencia , Proteínas del Tejido Nervioso/genética , Activación Plaquetaria , Proteína Reelina , Serina Endopeptidasas/deficiencia , Serina Endopeptidasas/genética , Transducción de Señal , Trombosis/sangre , Trombosis/etiologíaRESUMEN
Disruption of colonic homeostasis caused by aberrant M1/M2 macrophage polarization and dysbiosis contributes to inflammatory bowel disease (IBD) pathogenesis. However, the molecular factors mediating colonic homeostasis are not well characterized. Here, we found that Ninjurin1 (Ninj1) limits colon inflammation by regulating macrophage polarization and microbiota composition under homeostatic conditions and during colitis development. Ninj1 deletion in mice induced hypersusceptibility to colitis, with increased prevalence of colitogenic Prevotellaceae strains and decreased immunoregulatory Lachnospiraceae strains. Upon co-housing (CoH) with WT mice, Ninj1-/- mice showed increased Lachnospiraceae and decreased Prevotellaceae abundance, with subsequent improvement of colitis. Under homeostatic conditions, M1 macrophage frequency was higher in the Ninj1-/- mouse colons than wild-type (WT) mouse colons, which may contribute to increased basal colonic inflammation and microbial imbalance. Following colitis induction, Ninj1 expression was increased in macrophages; meanwhile Ninj1-/- mice showed severe colitis development and impaired recovery, associated with decreased M2 macrophages and escalated microbial imbalance. In vitro, Ninj1 knockdown in mouse and human macrophages activated M1 polarization and restricted M2 polarization. Finally, the transfer of WT macrophages ameliorated severe colitis in Ninj1-/- mice. These findings suggest that Ninj1 mediates colonic homeostasis by modulating M1/M2 macrophage balance and preventing extensive dysbiosis, with implications for IBD prevention and therapy.
Asunto(s)
Moléculas de Adhesión Celular Neuronal/deficiencia , Colitis/metabolismo , Colitis/patología , Microbioma Gastrointestinal/fisiología , Macrófagos/metabolismo , Macrófagos/patología , Factores de Crecimiento Nervioso/deficiencia , Animales , Moléculas de Adhesión Celular Neuronal/metabolismo , Diferenciación Celular/fisiología , Línea Celular Tumoral , Colitis/microbiología , Colon/metabolismo , Colon/microbiología , Colon/patología , Modelos Animales de Enfermedad , Homeostasis/fisiología , Humanos , Inflamación/metabolismo , Inflamación/microbiología , Inflamación/patología , Enfermedades Inflamatorias del Intestino/metabolismo , Enfermedades Inflamatorias del Intestino/microbiología , Enfermedades Inflamatorias del Intestino/patología , Activación de Macrófagos/fisiología , Masculino , Ratones , Factores de Crecimiento Nervioso/metabolismo , Células THP-1/metabolismoRESUMEN
Synapse formation is a dynamic process essential for the development and maturation of the neuronal circuitry in the brain. At the synaptic cleft, trans-synaptic protein-protein interactions are major biological determinants of proper synapse efficacy. The balance of excitatory and inhibitory synaptic transmission (E-I balance) stabilizes synaptic activity, and dysregulation of the E-I balance has been implicated in neurodevelopmental disorders, including autism spectrum disorders. However, the molecular mechanisms underlying the E-I balance remain to be elucidated. Here, using single-cell transcriptomics, immunohistochemistry, and electrophysiology approaches to murine CA1 pyramidal neurons obtained from organotypic hippocampal slice cultures, we investigate neuroligin (Nlgn) genes that encode a family of postsynaptic adhesion molecules known to shape excitatory and inhibitory synaptic function. We demonstrate that the NLGN3 protein differentially regulates inhibitory synaptic transmission in a splice isoform-dependent manner at hippocampal CA1 synapses. We also found that distinct subcellular localizations of the NLGN3 isoforms contribute to the functional differences observed among these isoforms. Finally, results from single-cell RNA-Seq analyses revealed that Nlgn1 and Nlgn3 are the major murine Nlgn genes and that the expression levels of the Nlgn splice isoforms are highly diverse in CA1 pyramidal neurons. Our results delineate isoform-specific effects of Nlgn genes on the E-I balance in the murine hippocampus.
Asunto(s)
Región CA1 Hipocampal/metabolismo , Moléculas de Adhesión Celular Neuronal/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Sinapsis/fisiología , Animales , Moléculas de Adhesión Celular Neuronal/deficiencia , Moléculas de Adhesión Celular Neuronal/genética , Potenciales Postsinápticos Excitadores , Inmunohistoquímica , Potenciales Postsinápticos Inhibidores , Proteínas de la Membrana/deficiencia , Proteínas de la Membrana/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas del Tejido Nervioso/deficiencia , Proteínas del Tejido Nervioso/genética , Técnicas de Placa-Clamp , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Empalme del ARNRESUMEN
AIM: A Japanese individual with schizophrenia harboring a novel exonic deletion in RELN was recently identified by genome-wide copy-number variation analysis. Thus, the present study aimed to generate and analyze a model mouse to clarify whether Reln deficiency is associated with the pathogenesis of schizophrenia. METHODS: A mouse line with a novel RELN exonic deletion (Reln-del) was established using the CRISPR/Cas9 method to elucidate the underlying molecular mechanism. Subsequently, general behavioral tests and histopathological examinations of the model mice were conducted and phenotypic analysis of the cerebellar granule cell migration was performed. RESULTS: The phenotype of homozygous Reln-del mice was similar to that of reeler mice with cerebellar atrophy, dysplasia of the cerebral layers, and abrogated protein levels of cerebral reelin. The expression of reelin in heterozygous Reln-del mice was approximately half of that in wild-type mice. Conversely, behavioral analyses in heterozygous Reln-del mice without cerebellar atrophy or dysplasia showed abnormal social novelty in the three-chamber social interaction test. In vitro reaggregation formation and neuronal migration were severely altered in the cerebellar cultures of homozygous Reln-del mice. CONCLUSION: The present results in novel Reln-del mice modeled after our patient with a novel exonic deletion in RELN are expected to contribute to the development of reelin-based therapies for schizophrenia.