Browsing by Author "Zanlungo Matsuhiro, Silvana"

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    A Ribosomal Protein S10 Gene Is Found in the Mitochondrial Genome in Solanum Tuberosum
    (1994) Zanlungo Matsuhiro, Silvana; Holuigue Barros, María Loreto; Jordana, Xavier
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    Abnormalities of lipid metabolism, gallstone disease and gallbladder function
    (2011) Zanlungo Matsuhiro, Silvana; Miquel P., Juan Francisco; Rigotti Rivera, Attilio; Nervi, Flavio
    Gallstone disease is highly prevalent with a complex and multifactorial pathogenesis. Gallstones are closely related to the metabolic syndrome associated disease conditions in which abnormal regulation of lipid metabolism secondary to insulin resistance plays a major pathogenic role. Insulin resistance increases biliary cholesterol secretion and affects gallbladder (GB) motility. Regulation of lipid metabolism and energy homeostasis is complex and the GB has been considered to have a minor regulatory role in both the intestinal absorption of lipids and metabolic homeostasis of the whole body. In fact, ablation of the GB does not affect nutrient absorption or the ability to lead a normal life. GB function regulates the cycling of bile salts through the enterohepatic circulation. Bile salts have important signaling effects that can affect whole body metabolic homeostasis. The GB and intestinal mucosa are rich in the hormone FGF15/19 and the receptor TGR5, which participate in metabolic regulation. Recent evidence supports the hypothesis that cholecystectomy may not be innocuous and that the GB has a significant role in the regulation of hepatic triglyceride metabolism. This article provides information regarding recent advances in the understanding of the interaction between regulation of lipid metabolism, insulin resistance, gallstone disease and GB function.
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    Adenovirus-mediated hepatic syndecan-1 overexpression induces hepatocyte proliferation and hyperlipidaemia in mice
    (2007) Cortés, V.; Zanlungo Matsuhiro, Silvana; Brandan, Enrique; Rigotti Rivera, Attilio
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    Alteration of Gene Expression Profile in Niemann-Pick Type C Mice Correlates with Tissue Damage and Oxidative Stress
    (2011) Vázquez Rodríguez, Mary Carmen; Robledo Plaza, Fermín Alberto; Zanlungo Matsuhiro, Silvana
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    Amyloid-beta oligomers synaptotoxicity: The emerging role of epha4/c-Abl signaling in Alzheimer's disease
    (2018) Vargas, L. M.; Cerpa Nebott, Waldo Francisco; Munoz, F. J.; Zanlungo Matsuhiro, Silvana; Álvarez Rojas, Alejandra
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    Análisis y modulación de la vía de Catepsinas B y D en la fibrosis hepática en modelos in vitro e in vivo de la enfermedad de Niemann-Pick tipo C
    (2019) Oyarzún Isamitt, Juan Esteban; Zanlungo Matsuhiro, Silvana; Pontificia Universidad Católica de Chile. Escuela de Medicina
    La enfermedad de Niemann-Pick tipo C (NPC) es un desorden hereditario autosómico recesivo caracterizado por la acumulación de colesterol en los lisosomas. Esta enfermedad es causada por mutaciones en los genes que codifican para las proteínas NPC1 y NPC2, las cuales están implicadas en el eflujo del colesterol desde los lisosomas. La deficiencia de NPC1 ó NPC2 lleva a una acumulación primaria de colesterol libre lisosomal y posteriormente el consecuente daño celular. Si bien no se conoce del todo los mecanismos subyacentes por los cuales el colesterol libre generaría el daño hepático en la enfermedad de NPC, se han postulado diversas opciones, entre los que destaca el estrés oxidativo, la disfunción en la dinámica de endosomas y lisosomas, así como también la disfunción en la autofagia lisosomal. El sistema nervioso central (SNC) es el más afectado en los pacientes NPC, los cuales padecen una rápida neurodegeneración progresiva a edad temprana. Otro órgano muy afectado en los pacientes NPC es el hígado, ya que muchos pacientes padecen de enfermedad hepática incluso llegando a falla hepática fulminante. Sin embargo, las causas que conllevan al daño hepático en NPC han sido poco estudiadas y dilucidadas. En los hígados de pacientes NPC se ha reportado un aumento en el contenido de colesterol libre, fibrosis progresiva y apoptosis. Recientes reportes han postulado a las catepsinas B y D como potenciales candidatos en la vía que conecta la acumulación de colesterol libre con el daño hepático, particularmente con la fibrosis hepática. Considerando todos los antecedentes previos, se formuló la siguiente hipótesis: “Las vías de las catepsinas B y D contribuyen a la fibrosis hepática en la enfermedad de NiemannPick tipo C”. El objetivo general planteado fue: “Demostrar que las vías de las catepsinas B y D contribuyen a la fibrosis en modelos hepáticos in vitro e in vivo de la enfermedad de Niemann-Pick tipo C”. Los resultados de esta tesis muestran aumento en los niveles de catepsinas B y D, los que se correlacionaron con aumento en la fibrosis e inflamación en hígados de ratones NPC. Este aumento en la fibrosis también fue reproducido en los modelos hepáticos in vitro NPC. Interesantemente, la utilización de inhibidores de catepsinas B y D, CA-074 y pepstatina A, respectivamente, además de shRNA contra catepsina D, disminuyó el fenotipo pro-fibrótico en modelos celulares de hepatocitos y células estrelladas hepáticas NPC. Por otro lado, la sobreexpresión de catepsina B aumentó la fibrosis en los modelos in vitro. Los resultados obtenidos nos llevan a la conclusión que las catepsinas B y D participan en la fibrosis hepática en NPC y proponemos su inhibición como una aproximación terapéutica para tratar el daño hepático en esta enfermedad.
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    Apolipoprotein A-I deficiency does not affect biliary lipid secretion and gallstone formation in mice
    (2011) Amigo Boker, Ludwig Peter; Quiñones, Verónica; Leiva Mendoza, Andrea Alejandra; Busso, Dolores; Zanlungo Matsuhiro, Silvana; Nervi, Flavio; Rigotti Rivera, Attilio
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    Autophagy Induced by Toll-like Receptor Ligands Regulates Antigen Extraction and Presentation by B Cells
    (MDPI, 2022) Acharya, Mridu; Bozo, Juan Pablo; Diaz Munoz, Jheimmy Mariana; Guzman, Fanny; Lagos Orellana, Jonathan Alexander; Sagadiev, Sara; Stefani, Caroline; Yuseff Sepulveda, María Isabel; Zanlungo Matsuhiro, Silvana
    The engagement of B cells with surface-tethered antigens triggers the formation of an immune synapse (IS), where the local secretion of lysosomes can facilitate antigen uptake. Lysosomes intersect with other intracellular processes, such as Toll-like Rece
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    c-Abl activates RIPK3 signaling in Gaucher disease
    (2021) Yañez Henríquez, María José; Campos, F.; Marín Marín, Tamara Alejandra; Klein Posternack, Andrés David; Futerman, A. H.; Álvarez, Alejandra R.; Zanlungo Matsuhiro, Silvana
    Gaucher disease (GD) is caused by homozygous mutations in the GBA1 gene, which encodes the lysosomal β-glucosidase (GBA) enzyme. GD affects several organs and tissues, including the brain in certain variants of the disease. Heterozygous GBA1 variants are a major genetic risk factor for developing Parkinson's disease. The RIPK3 kinase is relevant in GD and its deficiency improves the neurological and visceral symptoms in a murine GD model. RIPK3 mediates necroptotic-like cell death: it is unknown whether the role of RIPK3 in GD is the direct induction of necroptosis or if it has a more indirect function by mediating necrosis-independent. Also, the mechanisms that activate RIPK3 in GD are currently unknown. In this study, we show that c-Abl tyrosine kinase participates upstream of RIPK3 in GD. We found that the active, phosphorylated form of c-Abl is increased in several GD models, including patient's fibroblasts and GBA null mice. Furthermore, its pharmacological inhibition with the FDA-approved drug Imatinib decreased RIPK3 signaling. We found that c-Abl interacts with RIPK3, that RIPK3 is phosphorylated at a tyrosine site, and that this phosphorylation is reduced when c-Abl is inhibited. Genetic ablation of c-Abl in neuronal GD and GD mice models significantly reduced RIPK3 activation and MLKL downstream signaling. These results showed that c-Abl signaling is a new upstream pathway that activates RIPK3 and that its inhibition is an attractive therapeutic approach for the treatment of GD.
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    c-Abl Inhibition Activates TFEB and Promotes Cellular Clearance in a Lysosomal Disorder
    (2020) Contreras, P. S.; Tapia Ossa, Pablo José; González Hódar, Lila Alejandra; Peluso, I.; Soldati, C.; Valls Jiménez, Cristián; Balboa Castillo, Elisa Ivana; Castro Alonso, Juan Cristóbal; Leal Reyes, Nancy Valeria; Zanlungo Matsuhiro, Silvana; Napolitano, G.; Matarese, M.; Heras, M. L.; Martinez, A.; Platt, F. M.; Sobota, A.; Winter, D.; Klein, A. D.; Medina, D. L.; Ballabio, A.; Alvarez, A. R.
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    c-Abl kinase at the crossroads of healthy synaptic remodeling and synaptic dysfunction in neurodegenerative diseases
    (2023) Gutiérrez García, Daniela A.; Chandía Cristi, América Valeska; Yanez, Maria Jose; Zanlungo Matsuhiro, Silvana; Álvarez Rojas, Alejandra
    Our ability to learn and remember depends on the active formation, remodeling, and elimination of synapses. Thus, the development and growth of synapses as well as their weakening and elimination are essential for neuronal rewiring. The structural reorganization of synaptic complexes, changes in actin cytoskeleton and organelle dynamics, as well as modulation of gene expression, determine synaptic plasticity. It has been proposed that dysregulation of these key synaptic homeostatic processes underlies the synaptic dysfunction observed in many neurodegenerative diseases. Much is known about downstream signaling of activated N-methyl-D-aspartate and a-amino-3-hydroxy5-methyl-4-isoazolepropionate receptors; however, other signaling pathways can also contribute to synaptic plasticity and long-lasting changes in learning and memory. The non-receptor tyrosine kinase c-Abl (ABL1) is a key signal transducer of intra and extracellular signals, and it shuttles between the cytoplasm and the nucleus. This review focuses on c-Abl and its synaptic and neuronal functions. Here, we discuss the evidence showing that the activation of c-Abl can be detrimental to neurons, promoting the development of neurodegenerative diseases. Nevertheless, c-Abl activity seems to be in a pivotal balance between healthy synaptic plasticity, regulating dendritic spines remodeling and gene expression after cognitive training, and synaptic dysfunction and loss in neurodegenerative diseases. Thus, c-Abl genetic ablation not only improves learning and memory and modulates the brain genetic program of trained mice, but its absence provides dendritic spines resiliency against damage. Therefore, the present review has been designed to elucidate the common links between c-Abl regulation of structural changes that involve the actin cytoskeleton and organelles dynamics, and the transcriptional program activated during synaptic plasticity. By summarizing the recent discoveries on c-Abl functions, we aim to provide an overview of how its inhibition could be a potentially fruitful treatment to improve degenerative outcomes and delay memory loss.
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    C-ABL kinase in Niemann Pick type a disease : its implication in the pathogenic mechanisms leading to autophagic flux alterations and neurodegeneration.
    (2020) Marín Marín, Tamara Alejandra; Zanlungo Matsuhiro, Silvana; Pontificia Universidad Católica de Chile. Facultad de Medicina
    Niemann-Pick type A (NPA) disease is a fatal lysosomal neurodegenerative and autosomal recessive disorder. It is characterized by deficiency in acid sphingomyelinase (ASM) and accumulation of sphingomyelin and cholesterol in lysosomes. Unfortunately, there is no cure for patients who die between 2-3 years of age. Previously we described that the c-Abl proapoptotic signaling pathway is key in neuronal death in different neurodegenerative diseases, including lysosomal disorders. Furthermore, recent studies show a role for c-Abl in autophagy and cellular clearance, processes that depend on the lysosome, and are essential for keeping cellular homeostasis. Indeed, autophagy dysfunctions are involved in different pathologies, including neurodegenerative diseases. Considering these antecedents, we propose to evaluate if c-Abl is hyperactivated and modulates autophagy and cellular clearance in NPA disease. The hypothesis of this thesis is that c-Abl hyperactivation blocks the autophagy flux contributing to the neuronal pathogenesis in Niemann Pick type A disease. Our general aim is to determine if c-Abl hyperactivation blocks the autophagy flux contributing to the neuronal pathogenesis in Niemann Pick type A disease. The specific aims are: 1) To determine if the c-Abl signaling pathway is hyperactivated and participates in NPA disease neurodegeneration and 2) To evaluate if hyperactivation of the c-Abl signaling pathway inhibits autophagy flux in NPA models. We used several NPA models including; fibroblasts from NPA patients, Neural Stem Cells derived from these fibroblasts and a NPA mouse. In these models we modulated c-Abl activity and evaluated cell death, cerebellar inflammation and autophagy flux. Our results show that: i) c-Abl is hyperactivated and contributes to the neurodegeneration in in vitro and in vivo NPA models; ii) There are lysosomal and autophagy alterations in NPA models; iii) c-Abl inhibition induces autophagy and decreases lipid accumulation in in vitro NPA models; iv) c-Abl inhibition decreases neuronal death and inflammation at the cerebellum and improves locomotor function in NPA mice and v) the downregulated genes in NPA fibroblasts increase their expression upon Imatinib treatment. Interestingly, these genes are direct or indirectly related with autophagy. These results give new antecedents to understand the role of c-Abl in autophagy regulation and its contribution to the NPA disease pathogenic mechanisms. Additionally, these results allow us to propose c-Abl inhibitors as a therapeutic option for this disease.
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    c-Abl links APP-BACE1 interaction promoting APP amyloidogenic processing in Niemann-Pick type C disease
    (2016) Yañez, M.; Belbin, O.; Estrada, L.; Leal, N.; Contreras, P.; Lleó, A.; Burgos, P.; Zanlungo Matsuhiro, Silvana; Álvarez Rojas, Alejandra
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    c-Abl Phosphorylates MFN2 to Regulate Mitochondrial Morphology in Cells under Endoplasmic Reticulum and Oxidative Stress, Impacting Cell Survival and Neurodegeneration
    (MDPI, 2023) Martinez Saavedra, Alexis; Lamaizon Muñoz, Cristián Nicolás; Valls Jimenez, Cristián; Llambi, Fabien; Leal Reyes, Nancy Valeria; Fitzgerald, Patrick; Guy, Cliff; Kaminsk,i Marcin M.; Inestrosa Cantin, Nibaldo; van Zundert, Brigitte; Cancino, Gonzalo; Dulcey, Andrés E.; Zanlungo Matsuhiro, Silvana; Marugan, Juan J.; Hetz, Claudio; Green, Douglas R.; Alvarez Rojas, Alejandra
    The endoplasmic reticulum is a subcellular organelle key in the control of synthesis, folding, and sorting of proteins. Under endoplasmic reticulum stress, an adaptative unfolded protein response is activated; however, if this activation is prolonged, cells can undergo cell death, in part due to oxidative stress and mitochondrial fragmentation. Here, we report that endoplasmic reticulum stress activates c-Abl tyrosine kinase, inducing its translocation to mitochondria. We found that endoplasmic reticulum stress-activated c-Abl interacts with and phosphorylates the mitochondrial fusion protein MFN2, resulting in mitochondrial fragmentation and apoptosis. Moreover, the pharmacological or genetic inhibition of c-Abl prevents MFN2 phosphorylation, mitochondrial fragmentation, and apoptosis in cells under endoplasmic reticulum stress. Finally, in the amyotrophic lateral sclerosis mouse model, where endoplasmic reticulum and oxidative stress has been linked to neuronal cell death, we demonstrated that the administration of c-Abl inhibitor neurotinib delays the onset of symptoms. Our results uncovered a function of c-Abl in the crosstalk between endoplasmic reticulum stress and mitochondrial dynamics via MFN2 phosphorylation.
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    c-Abl Phosphorylates MFN2 to Regulate Mitochondrial Morphology in Cells under Endoplasmic Reticulum and Oxidative Stress, Impacting Cell Survival and Neurodegeneration
    (De Gruyter, 2023) Martinez Saavedra, Alexis; Lamaizon Muñoz, Cristián Nicolás; Valls Jimenez, Cristián; Llambi, Fabien; Leal Reyes, Nancy Valeria; Fitzgerald, Patrick; Guy, Cliff; Kaminsk,i Marcin M.; Inestrosa Cantin, Nibaldo; van Zundert, Brigitte; Cancino, Gonzalo; Dulcey, Andrés E.; Zanlungo Matsuhiro, Silvana; Marugan, Juan J.; Hetz, Claudio; Green, Douglas R.; Alvarez Rojas, Alejandra
    The endoplasmic reticulum is a subcellular organelle key in the control of synthesis, folding, and sorting of proteins. Under endoplasmic reticulum stress, an adaptative unfolded protein response is activated; however, if this activation is prolonged, cells can undergo cell death, in part due to oxidative stress and mitochondrial fragmentation. Here, we report that endoplasmic reticulum stress activates c-Abl tyrosine kinase, inducing its translocation to mitochondria. We found that endoplasmic reticulum stress-activated c-Abl interacts with and phosphorylates the mitochondrial fusion protein MFN2, resulting in mitochondrial fragmentation and apoptosis. Moreover, the pharmacological or genetic inhibition of c-Abl prevents MFN2 phosphorylation, mitochondrial fragmentation, and apoptosis in cells under endoplasmic reticulum stress. Finally, in the amyotrophic lateral sclerosis mouse model, where endoplasmic reticulum and oxidative stress has been linked to neuronal cell death, we demonstrated that the administration of c-Abl inhibitor neurotinib delays the onset of symptoms. Our results uncovered a function of c-Abl in the crosstalk between endoplasmic reticulum stress and mitochondrial dynamics via MFN2 phosphorylation.
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    c-Abl Stabilizes HDAC2 Levels by Tyrosine Phosphorylation Repressing Neuronal Gene Expression in Alzheimer's Disease
    (2014) González Zúñiga, Marcelo Andrés; Contreras Soto, Pablo Andrés; Estrada Apablaza, Lisbell; Chamorro Veloso, David Daniel; Villagra, A.; Zanlungo Matsuhiro, Silvana; Seto, E.; Álvarez Rojas, Alejandra
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    c-Abl tyrosine kinase down-regulation as target for memory improvement in Alzheimer's disease
    (2023) Leon, Rilda; Gutierrez, Daniela A.; Pinto, Claudio; Morales Acevedo, Cristián Gonzalo; de la Fuente, Catalina; Riquelme, Cristobal; Cortés Castro, Bastián Ignacio; Gonzalez-Martin, Adrian; Chamorro, David; Espinosa, Nelson; Fuentealba Durand, Pablo José; Cancino Lobos, Gonzalo; Zanlungo Matsuhiro, Silvana; Dulcey, Andres E.; Marugan, Juan J.; Rojas, Alejandra Alvarez
    BackgroundGrowing evidence suggests that the non-receptor tyrosine kinase, c-Abl, plays a significant role in the pathogenesis of Alzheimer's disease (AD). Here, we analyzed the effect of c-Abl on the cognitive performance decline of APPSwe/PSEN1 & UDelta;E9 (APP/PS1) mouse model for AD. MethodsWe used the conditional genetic ablation of c-Abl in the brain (c-Abl-KO) and pharmacological treatment with neurotinib, a novel allosteric c-Abl inhibitor with high brain penetrance, imbued in rodent's chow. ResultsWe found that APP/PS1/c-Abl-KO mice and APP/PS1 neurotinib-fed mice had improved performance in hippocampus-dependent tasks. In the object location and Barnes-maze tests, they recognized the displaced object and learned the location of the escape hole faster than APP/PS1 mice. Also, APP/PS1 neurotinib-fed mice required fewer trials to reach the learning criterion in the memory flexibility test. Accordingly, c-Abl absence and inhibition caused fewer amyloid plaques, reduced astrogliosis, and preserved neurons in the hippocampus. DiscussionOur results further validate c-Abl as a target for AD, and the neurotinib, a novel c-Abl inhibitor, as a suitable preclinical candidate for AD therapies.
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    C-Abl Tyrosine Kinase Signaling: A New Player in AD Tau Pathology
    (2011) Estrada, L.; Zanlungo Matsuhiro, Silvana; Álvarez Rojas, Alejandra
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    Cholinergic abnormalities, endosomal alterations and up-regulation of nerve growth factor signaling in Niemann-Pick Type C disease
    (2012) Cabeza Huerta, Carolina Andrea; Figueroa, Alicia; Lazo Jerez, Oscar Marcelo; Galleguillos, Carolina; Pissani Alvear, Claudia; Klein, Andrés; Inestrosa Cantín, Nibaldo; Álvarez Rojas, Alejandra; Zanlungo Matsuhiro, Silvana; Bronfman C., Francisca; Gonzalez-Billault, Christian
    Abstract Background Neurotrophins and their receptors regulate several aspects of the developing and mature nervous system, including neuronal morphology and survival. Neurotrophin receptors are active in signaling endosomes, which are organelles that propagate neurotrophin signaling along neuronal processes. Defects in the Npc1 gene are associated with the accumulation of cholesterol and lipids in late endosomes and lysosomes, leading to neurodegeneration and Niemann-Pick type C (NPC) disease. The aim of this work was to assess whether the endosomal and lysosomal alterations observed in NPC disease disrupt neurotrophin signaling. As models, we used i) NPC1-deficient mice to evaluate the central cholinergic septo-hippocampal pathway and its response to nerve growth factor (NGF) after axotomy and ii) PC12 cells treated with U18666A, a pharmacological cellular model of NPC, stimulated with NGF. Results NPC1-deficient cholinergic cells respond to NGF after axotomy and exhibit increased levels of choline acetyl transferase (ChAT), whose gene is under the control of NGF signaling, compared to wild type cholinergic neurons. This finding was correlated with increased ChAT and phosphorylated Akt in basal forebrain homogenates. In addition, we found that cholinergic neurons from NPC1-deficient mice had disrupted neuronal morphology, suggesting early signs of neurodegeneration. Consistently, PC12 cells treated with U18666A presented a clear NPC cellular phenotype with a prominent endocytic dysfunction that includes an increased size of TrkA-containing endosomes and reduced recycling of the receptor. This result correlates with increased sensitivity to NGF, and, in particular, with up-regulation of the Akt and PLC-γ signaling pathways, increased neurite extension, increased phosphorylation of tau protein and cell death when PC12 cells are differentiated and treated with U18666A. Conclusions Our results suggest that the NPC cellular phenotype causes neuronal dysfunction through the abnormal up-regulation of survival pathways, which causes the perturbation of signaling cascades and anomalous phosphorylation of the cytoskeleton.
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    Complement Component C3 Participates in Early Stages of Niemann-Pick C Mouse Liver Damage
    (2020) Klein, A. D.; Gonzalez de la Vega, J. ; Zanlungo Matsuhiro, Silvana