Artículos (Fisiología Médica y Biofísica)
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Artículo CCAAT/Enhancer binding protein β induces motility and invasion of glioblastoma cells through transcriptional regulation of the calcium binding protein S100A4(Impact Journals, 2015-01-24) Aguilar Morante, Diana; Morales-García, J. A.; Santos, A.; Pérez-Castillo, A.; Universidad de Sevilla. Departamento de Fisiología Médica y Biofísica; Fundacion Mutua Madrilena; Instituto de Salud Carlos III; MINECO; Universidad de Sevilla. CTS-007: Fisiopatología de células madre neuralesWe have previously shown that decreased expression of CCAAT/enhancer binding protein β (C/EBPβ) inhibits the growth of glioblastoma cells and diminishes their transformation capacity and migration. In agreement with this, we showed that C/EBPβ depletion decreases the mRNA levels of different genes involved in metastasis and invasion. Among these, we found S100 calcium binding protein A4 (S100A4) to be almost undetectable in glioblastoma cells deficient in C/EBPβ. Here, we have evaluated the possible role of S100A4 in the observed effects of C/EBPβ in glioblastoma cells and the mechanism through which S100A4 levels are controlled by C/EBPβ. Our results show that C/EBPβ suppression significantly reduced the levels of S100A4 in murine GL261 and human T98G glioblastoma cells. By employing an S100A4-promoter reporter, we observed a significant induction in the transcriptional activation of the S100A4 gene by C/EBPβ. Furthermore, overexpression of S100A4 in C/EBPβ-depleted glioblastoma cells reverses the enhanced migration and motility induced by this transcription factor. Our data also point to a role of S100A4 in glioblastoma cell invasion and suggest that the C/EBPβ gene controls the invasive potential of GL261 and T98G cells through direct regulation of S100A4. Finally, this study indicates a role of C/EBPβ on the maintenance of the stem cell population present in GL261 glioblastoma cells.Artículo Neural crest derived progenitor cells contribute to tumor stroma and aggressiveness in stage 4/M neuroblastoma(Impact Journals, 2017-09-21) Linares Clemente, Pedro; Aguilar Morante, Diana; Rodríguez Prieto, Ismael; Ramírez, Gema; Torres, Carmen de; Santamaría, Vicente; Pascual-Vaca, Diego; Colmenero-Repiso, Ana; Vega Moreno, Francisco Manuel; Pardal Redondo, Ricardo; Universidad de Sevilla. Departamento de Biología Celular; Universidad de Sevilla. Departamento de Fisiología Médica y Biofísica; Asociacion Espanola contra el Cancer (AECC); European Research Council (ERC Starting Grant (CBSCs)); FEDER; Spanish Ministry of Economy and Competitiviness SAF; Universidad de Sevilla. CTS-007: Fisiopatología de células madre neuralesPediatric tumors arise upon oncogenic transformation of stem/progenitor cells during embryonic development. Given this scenario, the existence of non-tumorigenic stem cells included within the aberrant tumoral niche, with a potential role in tumor biology, is an intriguing and unstudied possibility. Here, we describe the presence and function of non-tumorigenic neural crest-derived progenitor cells in aggressive neuroblastoma (NB) tumors. These cells differentiate into neural crest typical mesectodermal derivatives, giving rise to tumor stroma and promoting proliferation and tumor aggressiveness. Furthermore, an analysis of gene expression profiles in stage 4/M NB revealed a neural crest stem cell (NCSC) gene signature that was associated to stromal phenotype and high probability of relapse. Thus, this NCSC gene expression signature could be used in prognosis to improve stratification of stage 4/M NB tumors. Our results might facilitate the design of new therapies by targeting NCSCs and their contribution to tumor stroma.Artículo CCAAT/Enhancer binding protein beta silencing mitigates glial activation and neurodegeneration in a rat model of Parkinson's disease(Nature Research, 2017-10-19) Morales-García, J.A.; Gine, E.; Hernández-Encinas, E.; Aguilar Morante, Diana; Sierra-Magro, A.; Sanz-SanCristóbal, M.; Alonso-Gil, S.; Sánchez-Lanzas, R.; Castaño, J. G.; Santos, Á.; Pérez-Castillo, A.; Universidad de Sevilla. Departamento de Fisiología Médica y Biofísica; FEDER; Instituto de Salud Carlos III; MINECO; Universidad de Sevilla. CTS-007: Fisiopatología de células madre neuralesThe CCAAT/Enhancer binding protein β (C/EBPβ) is a transcription factor involved in numerous physiological as well as pathological conditions in the brain. However, little is known regarding its possible role in neurodegenerative disorders. We have previously shown that C/EBPβ regulates the expression of genes involved in inflammatory processes and brain injury. Here, we have analyzed the effects of C/EBPβ interference in dopaminergic cell death and glial activation in the 6-hydroxydopamine model of Parkinson's disease. Our results showed that lentivirus-mediated C/EBPβ deprivation conferred marked in vitro and in vivo neuroprotection of dopaminergic cells concomitant with a significant attenuation of the level of the inflammatory response and glial activation. Additionally, C/EBPβ interference diminished the induction of α-synuclein in the substantia nigra pars compacta of animals injected with 6-hydroxydopamine. Taking together, these results reveal an essential function for C/EBPβ in the pathways leading to inflammatory-mediated brain damage and suggest novel roles for C/EBPβ in neurodegenerative diseases, specifically in Parkinson's disease, opening the door for new therapeutic interventions.Artículo Complement component 3 (C3) expression in the hippocampus after excitotoxic injury: role of C/EBP beta(BMC, 2016-10-21) Hernandez-Encinas, E; Aguilar Morante, Diana; Morales-Garcia, JA; Gine, E; Sanz-SanCristobal, M; Santos, A.; Universidad de Sevilla. Departamento de Fisiología Médica y Biofísica; CIBERNED; CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI); FEDER funds; Instituto de Salud Carlos III; MINECO; Universidad de Sevilla. CTS-007: Fisiopatología de células madre neuralesBackground: The CCAAT/enhancer-binding protein β (C/EBPβ) is a transcription factor implicated in the control of proliferation, differentiation, and inflammatory processes mainly in adipose tissue and liver; although more recent results have revealed an important role for this transcription factor in the brain. Previous studies from our laboratory indicated that CCAAT/enhancer-binding protein β is implicated in inflammatory process and brain injury, since mice lacking this gene were less susceptible to kainic acid-induced injury. More recently, we have shown that the complement component 3 gene (C3) is a downstream target of CCAAT/enhancer-binding protein β and it could be a mediator of the proinflammatory effects of this transcription factor in neural cells. Methods: Adult male Wistar rats (8-12 weeks old) were used throughout the study. C/EBPβ+/+ and C/EBPβ-/- mice were generated from heterozygous breeding pairs. Animals were injected or not with kainic acid, brains removed, and brain slices containing the hippocampus analyzed for the expression of both CCAAT/enhancer-binding protein β and C3. Results: In the present work, we have further extended these studies and show that CCAAT/enhancer-binding protein β and C3 co-express in the CA1 and CA3 regions of the hippocampus after an excitotoxic injury. Studies using CCAAT/enhancer-binding protein β knockout mice demonstrate a marked reduction in C3 expression after kainic acid injection in these animals, suggesting that indeed this protein is regulated by C/EBPβ in the hippocampus in vivo. Conclusions: Altogether these results suggest that CCAAT/enhancer-binding protein β could regulate brain disorders, in which excitotoxic and inflammatory processes are involved, at least in part through the direct regulation of C3.Artículo Feedback modulation of orai1alpha and orai1beta protein content mediated by STIM proteins(Wiley, 2024) Nieto-Felipe, Joel; Macias-Diaz, Alvaro; Jimenez-Velarde, Vanesa; Lopez, Jose J.; Salido, Gines M.; Smani Hajami, Tarik; Jardin, Isaac; Rosado, Juan A.; Universidad de Sevilla. Departamento de Fisiología Médica y Biofísica; Agencia Estatal de Investigacion; Junta de ExtremaduraStore-operated Ca^2+ entry is a mechanism controlled by the filling state of the intracellular Ca^2+ stores, predominantly the endoplasmic reticulum (ER), where ER-resident proteins STIM1 and STIM2 orchestrate the activation of Orai channels in the plasma membrane, and Orai1 playing a predominant role. Two forms of Orai1, Orai1α and Orai1β, have been identified, which arises the question whether they are equally regulated by STIM proteins. We demonstrate that STIM1 preferentially activates Orai1α over STIM2, yet both STIM proteins similarly activate Orai1β. Under resting conditions, there is a pronounced association between STIM2 and Orai1α. STIM1 and STIM2 are also shown to influence the protein levels of the Orai1 variants, independently of Ca^2+ influx, via lysosomal degradation. Interestingly, Orai1α and Orai1β appear to selectively regulate the protein level of STIM1, but not STIM2. These observations offer crucial insights into the regulatory dynamics between STIM proteins and Orai1 variants, enhancing our understanding of the intricate processes that fine-tune intracellular Ca^2+ signaling.Artículo Molecular and micro-architectural mapping of gray matter alterations in psychosis(Springer Nature, 2024-09-12) García-San-Martín, Natalia; Bethlehem, Richard A. I.; Mihalik, Agoston; Seidlitz, Jakob; Sebenius, Isaac; Alemán-Morillo, Claudio; Ruiz Veguilla, Miguel; Crespo Facorro, Benedicto; Romero García, Rafael; Universidad de Sevilla. Departamento de Fisiología Médica y Biofísica; Universidad de Sevilla. Departamento de PsiquiatríaThe psychosis spectrum encompasses a heterogeneous range of clinical conditions associated with abnormal brain development. Detecting patterns of atypical neuroanatomical maturation across psychiatric disorders requires an interpretable metric standardized by age-, sex- and site-effect. The molecular and micro-architectural attributes that account for these deviations in brain structure from typical neurodevelopment are still unknown. Here, we aggregate structural magnetic resonance imaging data from 38,696 healthy controls (HC) and 1256 psychosis-related conditions, including first-degree relatives of schizophrenia (SCZ) and schizoaffective disorder (SAD) patients (n = 160), individuals who had psychotic experiences (n = 157), patients who experienced a first episode of psychosis (FEP, n = 352), and individuals with chronic SCZ or SAD (n = 587). Using a normative modeling approach, we generated centile scores for cortical gray matter (GM) phenotypes, identifying deviations in regional volumes below the expected trajectory for all conditions, with a greater impact on the clinically diagnosed ones, FEP and chronic. Additionally, we mapped 46 neurobiological features from healthy individuals (including neurotransmitters, cell types, layer thickness, microstructure, cortical expansion, and metabolism) to these abnormal centiles using a multivariate approach. Results revealed that neurobiological features were highly co-localized with centile deviations, where metabolism (e.g., cerebral metabolic rate of oxygen (CMRGlu) and cerebral blood flow (CBF)) and neurotransmitter concentrations (e.g., serotonin (5-HT) and acetylcholine (α4β2) receptors) showed the most consistent spatial overlap with abnormal GM trajectories. Taken together these findings shed light on the vulnerability factors that may underlie atypical brain maturation during different stages of psychosis.Artículo Mecanismos patogénicos en la fibrosis pulmonar idiopática. Implicación de los canales de Aquoporina 1(Asociación de Neumólogos del Sur, 2019) Rodríguez Portal, José Antonio; Arellano Orden, Elena; Suárez Luna, Nela; Gómez Izquierdo, L.; Barrera Talavera, María Dolores; Echevarría Irusta, Miriam; Universidad de Sevilla. Departamento de Fisiología Médica y Biofísica; Instituto de Biomedicina de Sevilla (IBIS); Universidad de Sevilla. CTS1047: Fisiopatología asociada a las Acuaporinas.La fibrosis pulmonar idiopática (FPI) es una enfermedad pulmonar intersticial difusa (EPID) y progresiva. La FPI resulta de la alteración en la reepitelización tras la lesión de las células epiteliales alveolares. Se produce un aumento en la apoptosis epitelial y en la síntesis de mediadores pro fibróticos, con la consiguiente proliferación de fibroblastos, transformación a miofibrobastos y el depósito incontrolado de matriz extracelular. La aquoporina 1 (AQP1), es una proteína que facilita el movimiento de agua entre el espacio aéreo pulmonar y el parénquima y se ha demostrado que se regula al alza en animales expuestos a hipoxia. La AQP1 se expresa en células endoteliales, pero no en el epitelio alveolar pulmonar. Más recientemente se ha asociado a la AQP1 en los mecanismos implicados en la proliferación celular. Nuestro objetivo principal ha sido evaluar la participación de las Aquoporinas (AQPs) pulmonares en la patogenia de la FPI. Hemos analizado la expresión de AQP1 en biopsias de pacientes diagnosticados con FPI según los criterios de la ATS/ERS/ALAT de 2011 y en otras patologías pulmonares tales como la neumonitis por hipersensibilidad, sarcoidosis y biopsias de controles sanos. Los resultado de la inmunohistoquímica revelaron una intensa expresión de AQP1 en neumocitos tipo II hiperplásicos solo en las muestras obtenidas de pacientes con FPI. Además hay una inducción de la expresión de AQP1 (mRNA y proteína) tras la estimulación con TGF-β lo que acompaña a los cambios típicos del proceso de transición epitelio mesenquimal. Por lo tanto, la aparición de AQP1 en las células hiperplásicas tipo II y su regulación podrían estar implicadas en la patogénesis de la FPI.Artículo Aquaporin-1 plays important role in proliferation by affecting cell cycle progression(Wiley, 2016-06-16) Galán-Cobo, Ana; Ramírez Lorca, Reposo; Toledo Aral, Juan José; Echevarría Irusta, Miriam; Universidad de Sevilla. Departamento de Fisiología Médica y Biofísica; Instituto de Biomedicina de Sevilla (IBIS)Aquaporin-1 (AQP1) has been associated with tumor development. Here, we investigated how AQP1 may affect cell proliferation. The proliferative rate of adult carotid body (CB) cells, known to proliferate under chronic hypoxia, was analyzed in wild-type (AQP1 +/+) and knock out (AQP1 -/-) mice, maintained in normoxia or exposed to hypoxia while BrdU was administered. Fewer numbers of total BrdU+ and TH-BrdU+ cells were observed in AQP1 -/- mice, indicating a role for AQP1 in CB proliferation. Then, by flow cytometry, cell cycle state and proliferation of cells overexpressing AQP1 were compared to those of wild-type cells. In the AQP1-overexpressing cells, we observed higher cell proliferation and percentages of cells in phases S and G2/M and fewer apoptotic cells after nocodazole treatment were detected by annexin V staining. Also in these cells, proteomic assays showed higher expression of cyclin D1 and E1 and microarray analysis revealed changes in many cell proliferation-related molecules, including, Zeb 2, Jun, NF-kβ, Cxcl9, Cxcl10, TNF, and the TNF receptor. Overall, our results indicate that the presence of AQP1 modifies the expression of key cell cycle proteins apparently related to increases in cell proliferation. This contributes to explaining the presence of AQP1 in many different tumors.Artículo Rearrangement of cell types in the rat carotid body neurogenic niche induced by chronic intermittent hypoxia(Wiley, 2023-01-17) Caballero Eraso, Candela; Colinas Miranda, Olalla; González Montelongo, Rafaela; Cabeza, Jose M.; Gao Chen, Lin; Pardal Redondo, Ricardo; López Barneo, José; Ortega Sáenz, Patricia; Universidad de Sevilla. Departamento de Fisiología Médica y Biofísica; Instituto de Biomedicina de Sevilla (IBIS); European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER); Junta de Andalucía. Consejería de Salud; Ministerio de Ciencias, Innovación y Salud.The carotid body (CB) is a prototypical acute oxygen (O2)-sensing organ that mediates reflex hyperventilation and increased cardiac output in response to hypoxaemia. CB overactivation, secondary to the repeated stimulation produced by the recurrent episodes of intermittent hypoxia, is believed to contribute to the pathogenesis of sympathetic hyperactivity present in sleep apnoea patients. Although CB functional plasticity induced by chronic intermittent hypoxia (CIH) has been demonstrated, the underlying mechanisms are not fully elucidated. Here, we show that CIH induces a small increase in CB volume and rearrangement of cell types in the CB, characterized by a mobilization of immature quiescent neuroblasts, which enter a process of differentiation into mature, O2-sensing and neuron-like, chemoreceptor glomus cells. Prospective isolation of individual cell classes has allowed us to show that maturation of CB neuroblasts is paralleled by an upregulation in the expression of specific glomus cell genes involved in acute O2-sensing. CIH enhances mitochondrial responsiveness to hypoxia in maturing neuroblasts as well as in glomus cells. These data provide novel perspectives on the pathogenesis of CB-mediated sympathetic overflow that may lead to the development of new pharmacological strategies of potential applicability in sleep apnoea patients.Artículo Carotid body function in tyrosine hydroxylase conditional Olfr78 knockout mice(Oxford University Press, 2024-02-22) Colinas Miranda, Olalla; Mombaerts, Peter; López Barneo, José; Ortega Sáenz, Patricia; Universidad de Sevilla. Departamento de Fisiología Médica y Biofísica; Instituto de Biomedicina de Sevilla (IBIS); Ministerio de Ciencia e Innovación (MICIN). EspañaThe Olfr78 gene encodes a G-protein-coupled olfactory receptor that is expressed in several ectopic sites. Olfr78 is one of the most abundant mRNA species in carotid body (CB) glomus cells. These cells are the prototypical oxygen (O2) sensitive arterial chemoreceptors, which, in response to lowered O2 tension (hypoxia), activate the respiratory centers to induce hyperventilation. It has been proposed that Olfr78 is a lactate receptor and that glomus cell activation by the increase in blood lactate mediates the hypoxic ventilatory response (HVR). However, this proposal has been challenged by several groups showing that Olfr78 is not a physiologically relevant lactate receptor and that the O2-based regulation of breathing is not affected in constitutive Olfr78 knockout mice. In another study, constitutive Olfr78 knockout mice were reported to have altered systemic and CB responses to mild hypoxia. To further characterize the functional role of Olfr78 in CB glomus cells, we here generated a conditional Olfr78 knockout mouse strain and then restricted the knockout to glomus cells and other catecholaminergic cells by crossing with a tyrosine hydroxylase-specific Cre driver strain (TH-Olfr78 KO mice). We find that TH-Olfr78 KO mice have a normal HVR. Interestingly, glomus cells of TH-Olfr78 KO mice exhibit molecular and electrophysiological alterations as well as a reduced dopamine content in secretory vesicles and neurosecretory activity. These functional characteristics resemble those of CB neuroblasts in wild-type mice. We suggest that, although Olfr78 is not essential for CB O2 sensing, activation of Olfr78-dependent pathways is required for maturation of glomus cells.Artículo Presenilin/γ-Secretase Regulates Neurexin Processing at Synapses(Public Library of Science, 2011-04-29) Saura, Carlos A.; Servián Morilla, Emilia; Gómez Scholl, Francisco Manuel; Universidad de Sevilla. Departamento de Fisiología Médica y Biofísica; Consejería de Innovación, Ciencia y Empresa. Junta de Andalucía; Ministerio de Ciencia e Innovación (MICIN). EspañaNeurexins are a large family of neuronal plasma membrane proteins, which function as trans-synaptic receptors during synaptic differentiation. The binding of presynaptic neurexins to postsynaptic partners, such as neuroligins, has been proposed to participate in a signaling pathway that regulates synapse formation/stabilization. The identification of mutations in neurexin genes associated with autism and mental retardation suggests that dysfunction of neurexins may underlie synaptic defects associated with brain disorders. However, the mechanisms that regulate neurexin function at synapses are still unclear. Here, we show that neurexins are proteolytically processed by presenilins (PS), the catalytic components of the γ-secretase complex that mediates the intramembraneous cleavage of several type I membrane proteins. Inhibition of PS/γ-secretase by using pharmacological and genetic approaches induces a drastic accumulation of neurexin C-terminal fragments (CTFs) in cultured rat hippocampal neurons and mouse brain. Neurexin-CTFs accumulate mainly at the presynaptic terminals of PS conditional double knockout (PS cDKO) mice lacking both PS genes in glutamatergic neurons of the forebrain. The fact that loss of PS function enhances neurexin accumulation at glutamatergic terminals mediated by neuroligin-1 suggests that PS regulate the processing of neurexins at glutamatergic synapses. Interestingly, presenilin 1 (PS1) is recruited to glutamatergic terminals mediated by neuroligin-1, thus concentrating PS1 at terminals containing β-neurexins. Furthermore, familial Alzheimer's disease (FAD)-linked PS1 mutations differentially affect β-neurexin-1 processing. Expression of PS1 M146L and PS1 H163R mutants in PS−/− cells rescues the processing of β-neurexin-1, whereas PS1 C410Y and PS1 ΔE9 fail to rescue the processing defect. These results suggest that PS regulate the synaptic function and processing of neurexins at glutamatergic synapses, and that impaired neurexin processing by PS may play a role in FAD.Artículo Dual-promoter lentiviral vectors for constitutive and regulated gene expression in neurons(Elsevier, 2008-02-15) Gascón, Sergio; Páez Gómez, Juan A.; Díaz-Guerra, Margarita; Scheiffele, Peter; Gómez Scholl, Francisco Manuel; Universidad de Sevilla. Departamento de Fisiología Médica y BiofísicaGene transfer methods for efficient co-expression of exogenous proteins in neurons are crucial tools towards the understanding of the molecular basis of the central nervous system. Lentiviruses are retroviral vectors that can transduce a wide variety of cells including differentiated neurons. In this work, we have generated lentiviral vectors containing dual promoters that allow efficient co-expression of exogenous proteins in neurons. We show that insertion of two copies of a human synapsin promoter/WPRE cassette in a single lentiviral vector directs robust co-expression of cDNAs in cultured neurons, while excluding expression in the surrounding glial cells. Furthermore, insertion of the tetracycline-inducible system (Tet-off) controlled by the synapsin promoter results in tightly regulated expression of EGFP when used as a transgene in cultured neurons. Transduction of primary neurons with this inducible system leads to a 100-fold increase in EGFP mRNA levels in the absence of doxycycline. In transduced cultures, EGFP transcription is inhibited within 24 h upon addition of doxycycline. The viral systems we developed here provide neuron-specific and regulated expression mediated by single lentiviral vectors and will prove valuable tools for the study of neuronal function.Artículo Rare variants analysis of neurexin-1β in autism reveals a novel start codon mutation affecting protein levels at synapses(Lippincott, Williams & Wilkins, 2013-08-07) Camacho García, Rafael J.; Hervás, Amaia; Toma, Claudio; Balmaña, Noemí; Cormand, Bru; Martinez-Mir, Amalia; Gómez Scholl, Francisco Manuel; Universidad de Sevilla. Departamento de Fisiología Médica y Biofísica; Agencia de Gestio d\'Ajuts Universitaris i de Recerca-AGAUR, Generalitat de Catalunya; European Union (UE); Fundaciò La Maratò de TV3; Fundación Alicia Koplowitz; Instituto de Salud Carlos III; Ministerio de Economía y Competitividad (MINECO). EspañaNeurexins are synaptic plasma membrane proteins encoded by three genes (NRXN1, -2, -3) with alternative promoters. Mutations in neurexin genes have been identified in different neurodevelopmental disorders, including autism. Recently, two point mutations altering the translation initiation site of NRXN1β (c.−3G>T and c.3G>T) have been described in patients with autism and mental retardation. In this study, we analyzed the NRXN1β gene in a sample of 153 patients with autism. We report the identification of a novel mutation, c.3G>A (p.Met1), affecting the translation initiation site. Expression analysis showed that the c.3G>A mutation switches the translation start site of NRXN1β to an in-frame downstream methionine and decreases synaptic levels of the mutant protein in cultured neurons. These data reinforce a role for synaptic defects of NRXN1β in neurodevelopmental disorders.Artículo A truncating mutation in Alzheimer's disease inactivates neuroligin-1 synaptic function(Elsevier, 2015-09-03) Tristán Clavijo, Enriqueta; Camacho García, Rafael J.; Robles Lanuza, Estefanía; Ruiz, Agustín; Van der Zee, Julie; Van Broeckhoven, Christine; Hernandez, Isabel; Martinez-Mir, Amalia; Gómez Scholl, Francisco Manuel; Universidad de Sevilla. Departamento de Fisiología Médica y Biofísica; Instituto de Salud Carlos III; Junta de AndalucíaNeuroligins (NLs) are cell-adhesion proteins that regulate synapse formation and function. Neuroligin 1 (NL1) promotes the formation of glutamatergic synapses and mediates long-term potentiation in mouse models. Thus, altered NL1 function could mediate the synaptic and memory deficits associated with Alzheimer's disease (AD). Here, we describe a frameshift mutation, c.875_876insTT, in the neuroligin 1 gene (NLGN1) in a patient with AD and familial history of AD. The insertion generates a premature stop codon in the extracellular domain of NL1 (p.Thr271fs). Expression of mutant NL1 shows accumulation of truncated NL1 proteins in the endoplasmic reticulum. In hippocampal neurons, the p.Thr271fs mutation abolishes the ability of NL1 to promote the formation of glutamatergic synapses. Our data support a role for inactivating mutations in NLGN1 in AD. Previous studies have reported rare mutations in X-linked NLGNL3 and NLGNL4 genes in patients with autism, which result in the inactivation of the mutant alleles. Therefore, together with a role in neurodevelopmental disorders, altered NL function could underlie the molecular mechanisms associated with brain diseases in the elderly.Artículo Molecular and Cellular Mechanisms of Synaptopathies(Wiley Open Access, 2017-04-30) Ardiles, Álvaro O.; Grabrucker, Andreas M.; Gómez Scholl, Francisco Manuel; Rudenko, Gabby; Borsello, Tiziana; Universidad de Sevilla. Departamento de Fisiología Médica y Biofísica; NIMH NIH HHSSynapses, contact points between neurons, are essential elements supporting the ability of neurons to communicate and to transmit relevant information to each other. They play an integral role in brain development and wiring neurons into neural circuits, for example, those related to our behavior. Therefore, alterations affecting the integrity and/or functionality of synapses can lead to synaptic pathologies or synaptopathies. For instance, many neurological disorders including Alzheimer’s disease, Down syndrome, epilepsy, and Parkinson’s disease and neurodevelopmental disorders such as autism spectrum disorders, intellectual disability, and fragile X syndrome have consistently been reported to exhibit abnormalities in synaptic composition, morphology, and function. This special issue discusses various aspects of the molecular interactions that underlie synaptic protein networks and the complex signaling pathways that are activated by them, knowledge that is crucial to understand the cellular and molecular mechanisms involved in different synaptopathies. Synapses comprise a presynaptic compartment, consisting of the axon terminal and their protein machinery implicated in the release of neurotransmitters. Upon exocytosis of presynaptic vesicles, neurotransmitters spill out into the extracellular space called the “synaptic cleft” and diffuse to reach a postsynaptic compartment, composed of the protein machinery that receives and transduces the neurotransmitter-induced signals [1]. Most synaptopathies directly or indirectly affect the molecular repertoire of synaptic proteins.Artículo Proteolytic Processing of Neurexins by Presenilins Sustains Synaptic Vesicle Release(Society for Neuroscience, 2018-01-24) Servián Morilla, Emilia; Robles Lanuza, Estefanía; Sánchez Hidalgo, Ana Carmen; Camacho García, Rafael J.; Páez Gómez, Juan A.; Mavillard Saborido, Fabiola; Saura, Carlos A.; Martinez-Mir, Amalia; Gómez Scholl, Francisco Manuel; Universidad de Sevilla. Departamento de Fisiología Médica y Biofísica; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER); Junta de Andalucía; Ministerio de Economía y Competitividad (MINECO). EspañaProteolytic processing of synaptic adhesion components can accommodate the function of synapses to activity-dependent changes. The adhesion system formed by neurexins (Nrxns) and neuroligins (Nlgns) bidirectionally orchestrate the function of presynaptic and postsynaptic terminals. Previous studies have shown that presenilins (PS), components of the gamma-secretase complex frequently mutated in familial Alzheimer's disease, clear from glutamatergic terminals the accumulation of Nrxn C-terminal fragments (Nrxn-CTF) generated by ectodomain shedding. Here, we characterized the synaptic consequences of the proteolytic processing of Nrxns in cultured hippocampal neurons from mice and rats of both sexes. We show that activation of presynaptic Nrxns with postsynaptic Nlgn1 or inhibition of ectodomain shedding in axonal Nrxn1-β increases presynaptic release at individual terminals, likely reflecting an increase in the number of functional release sites. Importantly, inactivation of PS inhibits presynaptic release downstream of Nrxn activation, leaving synaptic vesicle recruitment unaltered. Glutamate-receptor signaling initiates the activity-dependent generation of Nrxn-CTF, which accumulate at presynaptic terminals lacking PS function. The sole expression of Nrxn-CTF decreases presynaptic release and calcium flux, recapitulating the deficits due to loss of PS function. Our data indicate that inhibition of Nrxn processing by PS is deleterious to glutamatergic function.Artículo A Neuroligin-1 mutation associated with Alzheimer’s disease produces memory and age-dependent impairments in hippocampal plasticity(Cell Press, 2023-05-13) Arias-Aragón, Francisco; Tristán Clavijo, Enriqueta; Martínez Gallego, Irene; Robles Lanuza, Estefanía; Coatl-Cuaya, Heriberto; Martín-Cuevas, Celia; Sánchez Hidalgo, Ana Carmen; Rodríguez Moreno, Antonio; Martínez Mir, Amalia; Gómez Scholl, Francisco Manuel; Universidad de Sevilla. Departamento de Fisiología Médica y Biofísica; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER); Junta de Andalucía; Ministerio de Ciencia, Innovación y Universidades (MICINN). España; Ministerio de Economia, Industria y Competitividad (MINECO). España; Formación de Profesorado Universitario predoctoral fellowship del Ministerio de UniversidadesAlzheimer’s disease (AD) is characterized by memory impairments and age-dependent synapse loss. Experimental and clinical studies have shown decreased expression of the glutamatergic protein Neuroligin-1 (Nlgn1) in AD. However, the consequences of a sustained reduction of Nlgn1 are unknown. Here, we generated a knockin mouse that reproduces the NLGN1 Thr271fs mutation, identified in heterozygosis in a familial case of AD. We found that Nlgn1 Thr271fs mutation abolishes Nlgn1 expression in mouse brain. Importantly, heterozygous Nlgn1 Thr271fs mice showed delay-dependent amnesia for recognition memory. Electrophysiological recordings uncovered age-dependent impairments in basal synaptic transmission and long-term potentiation (LTP) in CA1 hippocampal neurons of heterozygous Nlgn1 Thr271fs mice. In contrast, homozygous Nlgn1 Thr271fs mice showed impaired fear-conditioning memory and normal basal synaptic transmission, suggesting unshared mechanisms for a partial or total loss of Nlgn1. These data suggest that decreased Nlgn1 may contribute to the synaptic and memory deficits in AD.
Artículo Microglia mitochondrial complex I deficiency during development induces glial dysfunction and early lethality(Nature, 2024-07-24) Mora Romero, Bella; Capelo Carrasco, Nicolás; Pérez Moreno, Juan José; Álvarez Vergara, María Isabel; Trujillo Estrada, Laura Isabel; Romero Molina, Carmen; Martínez Márquez, Emilio; Morano Catalan, Noelia; Vizuete Chacón, María Luisa; López Barneo, José; Nieto González, José Luis; García-Junco Clemente, Pablo; Vitorica Ferrández, Francisco Javier; Gutiérrez, Antonia; Macías, David; Rosales Nieves, Alicia E.; Pascual Bravo, Alberto; Universidad de Sevilla. Departamento de Biología Celular; Universidad de Sevilla. Departamento de Bioquímica y Biología Molecular; Universidad de Sevilla. Departamento de Fisiología Médica y Biofísica; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España; Instituto de Salud Carlos III; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER); Junta de AndalucíaPrimary mitochondrial diseases (PMDs) are associated with pediatric neurological disorders and are traditionally related to oxidative phosphorylation system (OXPHOS) defects in neurons. Interestingly, both PMD mouse models and patients with PMD show gliosis, and pharmacological depletion of microglia, the innate immune cells of the brain, ameliorates multiple symptoms in a mouse model. Given that microglia activation correlates with the expression of OXPHOS genes, we studied whether OXPHOS deficits in microglia may contribute to PMDs. We first observed that the metabolic rewiring associated with microglia stimulation in vitro (via IL-33 or TAU treatment) was partially changed by complex I (CI) inhibition (via rotenone treatment). In vivo, we generated a mouse model deficient for CI activity in microglia (MGcCI). MGcCI microglia showed metabolic rewiring and gradual transcriptional activation, which led to hypertrophy and dysfunction in juvenile (1-month-old) and adult (3-month-old) stages, respectively. MGcCI mice presented widespread reactive astrocytes, a decrease of synaptic markers accompanied by an increased number of parvalbumin neurons, a behavioral deficit characterized by prolonged periods of immobility, loss of weight and premature death that was partially rescued by pharmacologic depletion of microglia. Our data demonstrate that microglia development depends on mitochondrial CI and suggest a direct microglial contribution to PMDs.Artículo The Complex Role of Store Operated Calcium Entry Pathways and Related Proteins in the Function of Cardiac, Skeletal and Vascular Smooth Muscle Cells(Frontiers Media, 2018-03-21) Ávila Medina, Javier; Mayoral González, Isabel; Dominguez Rodriguez, Alejandro; Gallardo Castillo, Isabel; Ribas Serna, Juan; Ordóñez Fernández, Antonio; Rosado, Juan Antonio; Smani Hajami, Tarik; Universidad de Sevilla. Departamento de Estomatología; Universidad de Sevilla. Departamento de Fisiología Médica y Biofísica; Junta de Andalucía; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER); Instituto de Salud Carlos III; Ministerio de Economía y Competitividad (MINECO). EspañaCardiac, skeletal, and smooth muscle cells shared the common feature of contraction in response to different stimuli. Agonist-induced muscle's contraction is triggered by a cytosolic free Ca2+ concentration increase due to a rapid Ca2+ release from intracellular stores and a transmembrane Ca2+ influx, mainly through L-type Ca2+ channels. Compelling evidences have demonstrated that Ca2+ might also enter through other cationic channels such as Store-Operated Ca2+ Channels (SOCCs), involved in several physiological functions and pathological conditions. The opening of SOCCs is regulated by the filling state of the intracellular Ca2+ store, the sarcoplasmic reticulum, which communicates to the plasma membrane channels through the Stromal Interaction Molecule 1/2 (STIM1/2) protein. In muscle cells, SOCCs can be mainly non-selective cation channels formed by Orai1 and other members of the Transient Receptor Potential-Canonical (TRPC) channels family, as well as highly selective Ca2+ Release-Activated Ca2+ (CRAC) channels, formed exclusively by subunits of Orai proteins likely organized in macromolecular complexes. This review summarizes the current knowledge of the complex role of Store Operated Calcium Entry (SOCE) pathways and related proteins in the function of cardiac, skeletal, and vascular smooth muscle cells.Artículo Valor pronóstico de la bioimpedancia eléctrica medida con el dispositivo IVOL en la insuficiencia cardiaca aguda(Elsevier, 2024) Gutiérrez Carretero, Encarnación; Campos, Ana Maria; Gimenez-Miranda, Luis; Rezaei, Kambitz; Pena, Amelia; Rossel, Javier; Praena, Juan Manuel; Smani Hajami, Tarik; Ordonez, Antonio; Medrano Ortega, Francisco Javier; Universidad de Sevilla. Departamento de Cirugía; Universidad de Sevilla. Departamento de Fisiología Médica y Biofísica; Universidad de Sevilla. Departamento de MedicinaIntroducción y objetivos: La evaluación actual de la insuficiencia cardiaca (IC) aguda no permite predecir adecuadamente su evolución. La bioimpedancia eléctrica (BI) permite conocer el estado de volemia, hasta ahora solo con equipos fijos. Hemos desarrollado y validado un dispositivo portátil e inalámbrico para medir la BI en el tobillo (IVOL). El objetivo del estudio es conocer el valor pronóstico a largo plazo de la medición puntual de la BI con IVOL en pacientes con IC aguda. Métodos: Estudio de cohorte prospectivo de pacientes no seleccionados ingresados por IC aguda en un hospital de tercer nivel. Se analizó la asociación entre la BI y diferentes variables (clínicas, analíticas y ecocardiográficos) al ingreso y evolución clínica. Resultados: Se incluyeron 76 pacientes (edad media 66,1 anos, ˜ 71,1% varones, 68,4% hipertensos, 34,2% diabéticos, NT-ProBNP medio: 7.103 pg/ml). De ellos, el 52,6% con fracción de eyección del ventrículo izquierdo (FEVI) no preservada (< 50%) y el 56,6% con disfunción del ventrículo derecho (VD). El 26,3% fallecieron durante un seguimiento medio de 35,8 meses. La supervivencia en pacientes con BI ≤ 21,8 fue menor, globalmente, y en los subgrupos de pacientes sin FEVI preservada y con disfunción del VD; p < 0,008). En el análisis multivariante una BI ≥ 21,8 fue un factor independiente de supervivencia (HR: 0,242; IC 95%: 0,86-0,681; p = 0,007). Conclusiones: Los valores de la BI medidos con IVOL pueden ser un predictor independiente de mortalidad a largo plazo en pacientes hospitalizados por IC aguda. Este valor pronóstico se mantiene en pacientes con FEVI no preservada y con disfunción ventricular derecha.