RESUMEN
Irisin is secreted by muscle, increases with exercise, and mediates certain favorable effects of physical activity. In particular, irisin has been shown to have beneficial effects in adipose tissues, brain, and bone. However, the skeletal response to exercise is less clear, and the receptor for irisin has not been identified. Here we show that irisin binds to proteins of the αV class of integrins, and biophysical studies identify interacting surfaces between irisin and αV/ß5 integrin. Chemical inhibition of the αV integrins blocks signaling and function by irisin in osteocytes and fat cells. Irisin increases both osteocytic survival and production of sclerostin, a local modulator of bone remodeling. Genetic ablation of FNDC5 (or irisin) completely blocks osteocytic osteolysis induced by ovariectomy, preventing bone loss and supporting an important role of irisin in skeletal remodeling. Identification of the irisin receptor should greatly facilitate our understanding of irisin's function in exercise and human health.
Asunto(s)
Adipocitos/metabolismo , Tejido Adiposo/metabolismo , Remodelación Ósea , Fibronectinas/metabolismo , Integrina alfaV/metabolismo , Osteocitos/metabolismo , Osteólisis/metabolismo , Adipocitos/patología , Animales , Línea Celular Tumoral , Femenino , Fibronectinas/genética , Células HEK293 , Humanos , Integrina alfaV/genética , Ratones , Osteocitos/patología , Osteólisis/genéticaRESUMEN
Exercise benefits the human body in many ways. Irisin is secreted by muscle, increased with exercise, and conveys physiological benefits, including improved cognition and resistance to neurodegeneration. Irisin acts via αV integrins; however, a mechanistic understanding of how small polypeptides like irisin can signal through integrins is poorly understood. Using mass spectrometry and cryo-EM, we demonstrate that the extracellular heat shock protein 90α (eHsp90α) is secreted by muscle with exercise and activates integrin αVß5. This allows for high-affinity irisin binding and signaling through an Hsp90α/αV/ß5 complex. By including hydrogen/deuterium exchange data, we generate and experimentally validate a 2.98 Å RMSD irisin/αVß5 complex docking model. Irisin binds very tightly to an alternative interface on αVß5 distinct from that used by known ligands. These data elucidate a non-canonical mechanism by which a small polypeptide hormone like irisin can function through an integrin receptor.
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Comunicación Celular , Fibronectinas , Humanos , Fibronectinas/metabolismo , Transducción de SeñalRESUMEN
Large-scale screens to identify protein interactions typically underperform with eukaryotic extracellular proteins. In this issue, Özkan et al. report development of a high-throughput assay designed specifically for extracellular proteins that uncovers a wealth of new interactions among three protein superfamilies in Drosophila and sets the stage for more extensive screens.
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Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citología , Drosophila melanogaster/metabolismo , Fibronectinas/metabolismo , Inmunoglobulinas/metabolismo , Mapas de Interacción de Proteínas , Proteínas/metabolismo , Animales , Proteínas Repetidas Ricas en LeucinaRESUMEN
Robust dendrite morphogenesis is a critical step in the development of reproducible neural circuits. However, little is known about the extracellular cues that pattern complex dendrite morphologies. In the model nematode Caenorhabditis elegans, the sensory neuron PVD establishes stereotypical, highly branched dendrite morphology. Here, we report the identification of a tripartite ligand-receptor complex of membrane adhesion molecules that is both necessary and sufficient to instruct spatially restricted growth and branching of PVD dendrites. The ligand complex SAX-7/L1CAM and MNR-1 function at defined locations in the surrounding hypodermal tissue, whereas DMA-1 acts as the cognate receptor on PVD. Mutations in this complex lead to dramatic defects in the formation, stabilization, and organization of the dendritic arbor. Ectopic expression of SAX-7 and MNR-1 generates a predictable, unnaturally patterned dendritic tree in a DMA-1-dependent manner. Both in vivo and in vitro experiments indicate that all three molecules are needed for interaction.
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Proteínas de Caenorhabditis elegans/metabolismo , Dendritas/metabolismo , Proteínas de la Membrana/metabolismo , Moléculas de Adhesión de Célula Nerviosa/metabolismo , Neurogénesis , Animales , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Fibronectinas/metabolismo , Proteínas de la Membrana/genética , Moléculas de Adhesión de Célula Nerviosa/genética , FilogeniaRESUMEN
Extracellular domains of cell surface receptors and ligands mediate cell-cell communication, adhesion, and initiation of signaling events, but most existing protein-protein "interactome" data sets lack information for extracellular interactions. We probed interactions between receptor extracellular domains, focusing on a set of 202 proteins composed of the Drosophila melanogaster immunoglobulin superfamily (IgSF), fibronectin type III (FnIII), and leucine-rich repeat (LRR) families, which are known to be important in neuronal and developmental functions. Out of 20,503 candidate protein pairs tested, we observed 106 interactions, 83 of which were previously unknown. We "deorphanized" the 20 member subfamily of defective-in-proboscis-response IgSF proteins, showing that they selectively interact with an 11 member subfamily of previously uncharacterized IgSF proteins. Both subfamilies interact with a single common "orphan" LRR protein. We also observed interactions between Hedgehog and EGFR pathway components. Several of these interactions could be visualized in live-dissected embryos, demonstrating that this approach can identify physiologically relevant receptor-ligand pairs.
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Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citología , Drosophila melanogaster/metabolismo , Fibronectinas/metabolismo , Inmunoglobulinas/metabolismo , Mapas de Interacción de Proteínas , Proteínas/metabolismo , Secuencia de Aminoácidos , Animales , Proteínas de Drosophila/química , Drosophila melanogaster/embriología , Fibronectinas/química , Proteínas Repetidas Ricas en Leucina , Ligandos , Datos de Secuencia Molecular , Filogenia , Estructura Terciaria de Proteína , Receptores de Superficie Celular/química , Receptores de Superficie Celular/metabolismo , Alineación de SecuenciaRESUMEN
The skull roof, or calvaria, is comprised of interlocking plates of bones that encase the brain. Separating these bones are fibrous sutures that permit growth. Currently, we do not understand the instructions for directional growth of the calvaria, a process which is error-prone and can lead to skeletal deficiencies or premature suture fusion (craniosynostosis, CS). Here, we identify graded expression of fibronectin (FN1) in the mouse embryonic cranial mesenchyme (CM) that precedes the apical expansion of calvaria. Conditional deletion of Fn1 or Wasl leads to diminished frontal bone expansion by altering cell shape and focal actin enrichment, respectively, suggesting defective migration of calvarial progenitors. Interestingly, Fn1 mutants have premature fusion of coronal sutures. Consistently, syndromic forms of CS in humans exhibit dysregulated FN1 expression, and we also find FN1 expression altered in a mouse CS model of Apert syndrome. These data support a model of FN1 as a directional substrate for calvarial osteoblast migration that may be a common mechanism underlying many cranial disorders of disparate genetic etiologies.
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Fibronectinas , Nacimiento Prematuro , Cráneo , Animales , Femenino , Humanos , Ratones , Señales (Psicología) , Modelos Animales de Enfermedad , Fibronectinas/metabolismo , Osteoblastos , Cráneo/citología , Cráneo/crecimiento & desarrollo , Cráneo/metabolismo , SuturasRESUMEN
Lawrence et al. report that fetal cortical boundaries are susceptible to morphogenetic stress that regulates a microglia state resembling postnatal, axon-tract associated microglia (ATM). This state performs a newfound function at these boundaries by preventing the formation of cavitary lesions, mediated in part by Spp1-regulated phagocytosis of fibronectin 1.
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Microglía , Microglía/fisiología , Animales , Humanos , Fagocitosis , Corteza Cerebral/embriología , Corteza Cerebral/citología , Encéfalo/embriología , Encéfalo/fisiología , Fibronectinas/metabolismoRESUMEN
Natural killer (NK) cells are innate lymphoid cells, and their presence within human tumors correlates with better prognosis. However, the mechanisms by which NK cells control tumors in vivo are unclear. Here, we used reflectance confocal microscopy (RCM) imaging in humans and in mice to visualize tumor architecture in vivo. We demonstrated that signaling via the NK cell receptor NKp46 (human) and Ncr1 (mouse) induced interferon-γ (IFN-γ) secretion from intratumoral NK cells. NKp46- and Ncr1-mediated IFN-γ production led to the increased expression of the extracellular matrix protein fibronectin 1 (FN1) in the tumors, which altered primary tumor architecture and resulted in decreased metastases formation. Injection of IFN-γ into tumor-bearing mice or transgenic overexpression of Ncr1 in NK cells in mice resulted in decreased metastasis formation. Thus, we have defined a mechanism of NK cell-mediated control of metastases in vivo that may help develop NK cell-dependent cancer therapies.
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Antígenos Ly/metabolismo , Fibronectinas/metabolismo , Interferón gamma/metabolismo , Células Asesinas Naturales/metabolismo , Receptor 1 Gatillante de la Citotoxidad Natural/metabolismo , Neoplasias/metabolismo , Animales , Western Blotting , Femenino , Citometría de Flujo , Técnica del Anticuerpo Fluorescente , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Masculino , Ratones , Microscopía Confocal , Metástasis de la Neoplasia/genética , Neoplasias/patología , Reacción en Cadena en Tiempo Real de la Polimerasa , Transducción de Señal/genéticaRESUMEN
Myokines and exosomes, originating from skeletal muscle, are shown to play a significant role in maintaining brain homeostasis. While exercise has been reported to promote muscle secretion, little is known about the effects of neuronal innervation and activity on the yield and molecular composition of biologically active molecules from muscle. As neuromuscular diseases and disabilities associated with denervation impact muscle metabolism, we hypothesize that neuronal innervation and firing may play a pivotal role in regulating secretion activities of skeletal muscles. We examined this hypothesis using an engineered neuromuscular tissue model consisting of skeletal muscles innervated by motor neurons. The innervated muscles displayed elevated expression of mRNAs encoding neurotrophic myokines, such as interleukin-6, brain-derived neurotrophic factor, and FDNC5, as well as the mRNA of peroxisome-proliferator-activated receptor γ coactivator 1α, a key regulator of muscle metabolism. Upon glutamate stimulation, the innervated muscles secreted higher levels of irisin and exosomes containing more diverse neurotrophic microRNAs than neuron-free muscles. Consequently, biological factors secreted by innervated muscles enhanced branching, axonal transport, and, ultimately, spontaneous network activities of primary hippocampal neurons in vitro. Overall, these results reveal the importance of neuronal innervation in modulating muscle-derived factors that promote neuronal function and suggest that the engineered neuromuscular tissue model holds significant promise as a platform for producing neurotrophic molecules.
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Factor Neurotrófico Derivado del Encéfalo , Exosomas , Músculo Esquelético , Exosomas/metabolismo , Animales , Músculo Esquelético/metabolismo , Músculo Esquelético/inervación , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Ratones , Fibronectinas/metabolismo , Neuronas Motoras/metabolismo , Interleucina-6/metabolismo , MicroARNs/metabolismo , MicroARNs/genética , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/metabolismo , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/genética , Neuronas/metabolismo , Factores de Crecimiento Nervioso/metabolismo , MioquinasRESUMEN
Cell migration modes can vary, depending on a number of environmental and intracellular factors. The high motility of the pathogenic amoeba Entamoeba histolytica is a decisive factor in its ability to cross the human colonic barrier. We used quantitative live imaging techniques to study the migration of this parasite on fibronectin, a key tissue component. Entamoeba histolytica amoebae on fibronectin contain abundant podosome-like structures. By using a laminar flow chamber, we determined that the adhesion forces generated on fibronectin were twice those on non-coated glass. When migrating on fibronectin, elongated amoeboid cells converted into fan-shaped cells characterized by the presence of a dorsal column of F-actin and a broad cytoplasmic extension at the front. The fan shape depended on the Arp2/3 complex, and the amoebae moved laterally and more slowly. Intracellular measurements of physical variables related to fluid dynamics revealed that cytoplasmic pressure gradients were weaker within fan-shaped cells; hence, actomyosin motors might be less involved in driving the cell body forward. We also found that the Rho-associated coiled-coil containing protein kinase regulated podosome dynamics. We conclude that E. histolytica spontaneously changes its migration mode as a function of the substrate composition. This adaptive ability might favour E. histolytica's invasion of human colonic tissue. By combining microfluidic experiments, mechanical modelling, and image analysis, our work also introduces a computational pipeline for the study of cell migration.
Asunto(s)
Movimiento Celular , Entamoeba histolytica , Fibronectinas , Entamoeba histolytica/metabolismo , Entamoeba histolytica/fisiología , Fibronectinas/metabolismo , Humanos , Movimiento Celular/fisiología , Entamebiasis/parasitología , Entamebiasis/metabolismo , Actinas/metabolismo , Podosomas/metabolismo , Adhesión Celular/fisiología , Proteínas Protozoarias/metabolismoRESUMEN
Spinal cord injury in mammals is thought to trigger scar formation with little regeneration of axons1-4. Here we show that a crush injury to the spinal cord in neonatal mice leads to scar-free healing that permits the growth of long projecting axons through the lesion. Depletion of microglia in neonatal mice disrupts this healing process and stalls the regrowth of axons, suggesting that microglia are critical for orchestrating the injury response. Using single-cell RNA sequencing and functional analyses, we find that neonatal microglia are transiently activated and have at least two key roles in scar-free healing. First, they transiently secrete fibronectin and its binding proteins to form bridges of extracellular matrix that ligate the severed ends of the spinal cord. Second, neonatal-but not adult-microglia express several extracellular and intracellular peptidase inhibitors, as well as other molecules that are involved in resolving inflammation. We transplanted either neonatal microglia or adult microglia treated with peptidase inhibitors into spinal cord lesions of adult mice, and found that both types of microglia significantly improved healing and axon regrowth. Together, our results reveal the cellular and molecular basis of the nearly complete recovery of neonatal mice after spinal cord injury, and suggest strategies that could be used to facilitate scar-free healing in the adult mammalian nervous system.
Asunto(s)
Microglía/fisiología , Traumatismos de la Médula Espinal/terapia , Regeneración de la Medula Espinal , Médula Espinal/citología , Médula Espinal/fisiología , Animales , Animales Recién Nacidos , Axones/efectos de los fármacos , Axones/fisiología , Cicatriz , Fibronectinas/metabolismo , Homeostasis , Ratones , Microglía/efectos de los fármacos , Inhibidores de Proteasas/farmacología , RNA-Seq , Análisis de la Célula Individual , Médula Espinal/patología , Traumatismos de la Médula Espinal/patología , Regeneración de la Medula Espinal/efectos de los fármacos , Cicatrización de Heridas/efectos de los fármacosRESUMEN
Mammalian FNDC5 encodes a protein precursor of Irisin, which is important for exercise-dependent regulation of whole-body metabolism. In a genetic screen in Drosophila, we identified Iditarod (Idit), which shows substantial protein homology to mouse and human FNDC5, as a regulator of autophagy acting downstream of Atg1/Atg13. Physiologically, Idit-deficient flies showed reduced exercise performance and defective cold resistance, which were rescued by exogenous expression of Idit. Exercise training increased endurance in wild-type flies, but not in Idit-deficient flies. Conversely, Idit is induced upon exercise training, and transgenic expression of Idit in wild-type flies increased endurance to the level of exercise trained flies. Finally, Idit deficiency prevented both exercise-induced increase in cardiac Atg8 and exercise-induced cardiac stress resistance, suggesting that cardiac autophagy may be an additional mechanism by which Idit is involved in the adaptive response to exercise. Our work suggests an ancient role of an Iditarod/Irisin/FNDC5 family of proteins in autophagy, exercise physiology, and cold adaptation, conserved throughout metazoan species.
Asunto(s)
Proteínas de Drosophila , Fibronectinas , Animales , Humanos , Ratones , Animales Modificados Genéticamente , Autofagia , Drosophila , Fibronectinas/metabolismo , Mamíferos , Factores de Transcripción , Proteínas de Drosophila/metabolismoRESUMEN
Tumor initiation at either primary or metastatic sites is an inefficient process in which tumor cells must fulfill a series of conditions. One critical condition involves the ability of individual tumor-initiating cells to overcome 'isolation stress', enabling them to survive within harsh isolating microenvironments that can feature nutrient stress, hypoxia, oxidative stress and the absence of a proper extracellular matrix (ECM). In response to isolation stress, tumor cells can exploit various adaptive strategies to develop stress tolerance and gain stemness features. In this Opinion, we discuss how strategies such as the induction of certain cell surface receptors and deposition of ECM proteins enable tumor cells to endure isolation stress, thereby gaining tumor-initiating potential. As examples, we highlight recent findings from our group demonstrating how exposure of tumor cells to isolation stress upregulates the G-protein-coupled receptor lysophosphatidic acid receptor 4 (LPAR4), its downstream target fibronectin and two fibronectin-binding integrins, α5ß1 and αvß3. These responses create a fibronectin-rich niche for tumor cells, ultimately driving stress tolerance, cancer stemness and tumor initiation. We suggest that approaches to prevent cancer cells from adapting to stress by suppressing LPAR4 induction, blocking its downstream signaling or disrupting fibronectin-integrin interactions hold promise as potential strategies for cancer treatment.
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Fibronectinas , Integrinas , Fibronectinas/metabolismo , Adhesión Celular/fisiología , Regulación hacia Arriba , Integrinas/metabolismo , Integrina alfa5beta1/metabolismo , Matriz Extracelular/metabolismo , Integrina alfaVbeta3/metabolismoRESUMEN
Placentas from pregnancies complicated by severe early-onset fetal growth restriction (FGR) exhibit diminished vascular development mediated by impaired angiogenesis, but underlying mechanisms remain unknown. In this study, we show that FGR endothelial cells demonstrate inherently reduced migratory capacity despite the presence of fibronectin, a matrix protein abundant in placental stroma that displays abnormal organization in FGR placentas. Thus, we hypothesized that aberrant endothelial-fibronectin interactions in FGR are a key mechanism underlying impaired FGR endothelial migration. Using human fetoplacental endothelial cells isolated from uncomplicated term control and FGR pregnancies, we assessed integrin α5ß1 and αvß3 regulation during cell migration. We show that endothelial integrin α5ß1 and αvß3 interactions with fibronectin are required for migration and that FGR endothelial cells responded differentially to integrin inhibition, indicating integrin dysregulation in FGR. Whole-cell expression was not different between groups. However, there were significantly more integrins in focal adhesions and reduced intracellular trafficking in FGR. These newly identified changes in FGR endothelial cellular processes represent previously unidentified mechanisms contributing to persistent angiogenic deficiencies in FGR.
Asunto(s)
Retardo del Crecimiento Fetal , Integrina alfaVbeta3 , Células Endoteliales/metabolismo , Femenino , Fibronectinas/genética , Fibronectinas/metabolismo , Humanos , Integrina alfa5beta1/genética , Integrina alfa5beta1/metabolismo , Integrina alfaVbeta3/genética , Integrina alfaVbeta3/metabolismo , Placenta/metabolismo , EmbarazoRESUMEN
H9N2 avian influenza is a low-pathogenic avian influenza circulating in poultry and wild birds worldwide and frequently contributes to chicken salpingitis that is caused by avian pathogenic Escherichia coli (APEC), leading to huge economic losses and risks for food safety. Currently, how the H9N2 virus contributes to APEC infection and facilitates salpingitis remains elusive. In this study, in vitro chicken oviduct epithelial cell (COEC) model and in vivo studies were performed to investigate the role of H9N2 viruses on secondary APEC infection, and we identified that H9N2 virus enhances APEC infection both in vitro and in vivo. To understand the mechanisms behind this phenomenon, adhesive molecules on the cell surface facilitating APEC adhesion were checked, and we found that H9N2 virus could upregulate the expression of fibronectin, which promotes APEC adhesion onto COECs. We further investigated how fibronectin expression is regulated by H9N2 virus infection and revealed that transforming growth factor beta (TGF-ß) signaling pathway is activated by the NS1 protein of the virus, thus regulating the expression of adhesive molecules. These new findings revealed the role of H9N2 virus in salpingitis co-infected with APEC and discovered the molecular mechanisms by which the H9N2 virus facilitates APEC infection, offering new insights to the etiology of salpingitis with viral-bacterial co-infections.IMPORTANCEH9N2 avian influenza virus (AIV) widely infects poultry and is sporadically reported in human infections. The infection in birds frequently causes secondary bacterial infections, resulting in severe symptoms like pneumonia and salpingitis. Currently, the mechanism that influenza A virus contributes to secondary bacterial infection remains elusive. Here we discovered that H9N2 virus infection promotes APEC infection and further explored the underlying molecular mechanisms. We found that fibronectin protein on the cell surface is vital for APEC adhesion and also showed that H9N2 viral protein NS1 increased the expression of fibronectin by activating the TGF-ß signaling pathway. Our findings offer new information on how AIV infection promotes APEC secondary infection, providing potential targets for mitigating severe APEC infections induced by H9N2 avian influenza, and also give new insights on the mechanisms on how viruses promote secondary bacterial infections in animal and human diseases.
Asunto(s)
Infecciones por Escherichia coli , Subtipo H9N2 del Virus de la Influenza A , Gripe Aviar , Enfermedades de las Aves de Corral , Salpingitis , Animales , Femenino , Humanos , Pollos , Escherichia coli , Fibronectinas/metabolismo , Subtipo H9N2 del Virus de la Influenza A/fisiología , Gripe Aviar/complicaciones , Oviductos/metabolismo , Aves de Corral , Enfermedades de las Aves de Corral/metabolismo , Enfermedades de las Aves de Corral/virología , Salpingitis/metabolismo , Salpingitis/veterinaria , Salpingitis/virología , Factor de Crecimiento Transformador beta/metabolismo , Proteínas Virales/metabolismo , Infecciones por Escherichia coli/complicaciones , Infecciones por Escherichia coli/veterinariaRESUMEN
Leucine-rich α2-glycoprotein-1 (LRG1) is overexpressed in various cancers, including non-small cell lung cancer (NSCLC), but its role in NSCLC cell metastasis is not well understood. In this study, NSCLC cell exosomes were analyzed using different techniques, and the impact of exosomal LRG1 on NSCLC cell behavior was investigated through various assays both in vitro and in vivo. The study revealed that LRG1, found abundantly in NSCLC cells and exosomes, enhanced cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT). Exosomal LRG1 was shown to promote NSCLC cell metastasis in animal models. Additionally, the interaction between LRG1 and fibronectin 1 (FN1) in the cytoplasm was identified. It was observed that FN1 could counteract the effects of LRG1 knockdown on cell regulation induced by exosomes derived from NSCLC cells. Overall, the findings suggest that targeting exosomal LRG1 or FN1 may hold therapeutic potential for treating NSCLC.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Movimiento Celular , Proliferación Celular , Exosomas , Fibronectinas , Glicoproteínas , Neoplasias Pulmonares , Carcinoma de Pulmón de Células no Pequeñas/patología , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/genética , Humanos , Exosomas/metabolismo , Exosomas/genética , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/genética , Proliferación Celular/genética , Fibronectinas/metabolismo , Fibronectinas/genética , Animales , Glicoproteínas/metabolismo , Glicoproteínas/genética , Movimiento Celular/genética , Ratones , Línea Celular Tumoral , Transición Epitelial-Mesenquimal/genética , Ratones Desnudos , Metástasis de la Neoplasia , Ratones Endogámicos BALB C , Regulación Neoplásica de la Expresión Génica , Células A549RESUMEN
Physical activity provides clinical benefit in Parkinson's disease (PD). Irisin is an exercise-induced polypeptide secreted by skeletal muscle that crosses the blood-brain barrier and mediates certain effects of exercise. Here, we show that irisin prevents pathologic α-synuclein (α-syn)-induced neurodegeneration in the α-syn preformed fibril (PFF) mouse model of sporadic PD. Intravenous delivery of irisin via viral vectors following the stereotaxic intrastriatal injection of α-syn PFF cause a reduction in the formation of pathologic α-syn and prevented the loss of dopamine neurons and lowering of striatal dopamine. Irisin also substantially reduced the α-syn PFF-induced motor deficits as assessed behaviorally by the pole and grip strength test. Recombinant sustained irisin treatment of primary cortical neurons attenuated α-syn PFF toxicity by reducing the formation of phosphorylated serine 129 of α-syn and neuronal cell death. Tandem mass spectrometry and biochemical analysis revealed that irisin reduced pathologic α-syn by enhancing endolysosomal degradation of pathologic α-syn. Our findings highlight the potential for therapeutic disease modification of irisin in PD.
Asunto(s)
Cuerpo Estriado , Fibronectinas , Enfermedad de Parkinson , alfa-Sinucleína , Animales , Cuerpo Estriado/metabolismo , Modelos Animales de Enfermedad , Neuronas Dopaminérgicas/metabolismo , Fibronectinas/administración & dosificación , Fibronectinas/genética , Fibronectinas/metabolismo , Ratones , Enfermedad de Parkinson/metabolismo , Enfermedad de Parkinson/terapia , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismoRESUMEN
Epithelial polarity is fundamental in maintaining barrier integrity and tissue protection. In cystic fibrosis (CF), apicobasal polarity of the airway epithelium is altered, resulting in increased apical fibronectin deposition and enhanced susceptibility to bacterial infections. Here, we evaluated the effect of highly effective modulator treatment (HEMT) on fibronectin apical deposition and investigated the intracellular mechanisms triggering the defect in polarity of the CF airway epithelium. To this end, primary cultures of CF (F508del variant) human airway epithelial cells (HAECs) and a HAEC line, Calu-3, knocked down for CFTR (CF transmembrane conductance regulator) were compared with control counterparts. We show that CFTR mutation in primary HAECs and CFTR knockdown cells promote the overexpression and oversecretion of TGF-ß1 and DKK1 when cultured at an air-liquid interface. These dynamic changes result in hyperactivation of the TGF-ß pathway and inhibition of the Wnt pathway through degradation of ß-catenin leading to imbalanced proliferation and polarization. The abnormal interplay between TGF-ß and Wnt signaling pathways is reinforced by aberrant Akt signaling. Pharmacological manipulation of TGF-ß, Wnt, and Akt pathways restored polarization of the F508del CF epithelium, a correction that was not achieved by HEMT. Our data shed new insights into the signaling pathways that fine-tune apicobasal polarization in primary airway epithelial cells and may provide an explanation to the mitigated efficacy of HEMT on lung infection in people with CF.
Asunto(s)
Polaridad Celular , Regulador de Conductancia de Transmembrana de Fibrosis Quística , Fibrosis Quística , Células Epiteliales , Péptidos y Proteínas de Señalización Intercelular , Proteínas Proto-Oncogénicas c-akt , Mucosa Respiratoria , Vía de Señalización Wnt , Humanos , Fibrosis Quística/metabolismo , Fibrosis Quística/patología , Fibrosis Quística/genética , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Polaridad Celular/efectos de los fármacos , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Péptidos y Proteínas de Señalización Intercelular/genética , Células Epiteliales/metabolismo , Células Epiteliales/patología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Mucosa Respiratoria/metabolismo , Mucosa Respiratoria/patología , beta Catenina/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Factor de Crecimiento Transformador beta1/metabolismo , Células Cultivadas , Línea Celular , Fibronectinas/metabolismoRESUMEN
Fibronectin (FN) is a major extracellular matrix (ECM) protein involved in a wide range of physiological processes, including cell migration. These FN-mediated cell migration events are essential to processes such as wound repair, cancer metastasis, and vertebrate development. This review synthesizes mainly current literature to provide an overview of the mechanoregulatory role of FN-mediated cell migration. Background on FN structure and role in mechanotransduction is provided. Cell migration concepts are introduced, including the general cell migration mechanism and classification of cell migration types. Then, FN-mediated events that directly affect cell migration are explored. Finally, a focus on FN in tissue repair and cancer migration is presented, as these topics represent a large amount of current research.
Asunto(s)
Fibronectinas , Neoplasias , Humanos , Fibronectinas/metabolismo , Matriz Extracelular/metabolismo , Mecanotransducción Celular , Movimiento Celular , Proteínas de la Matriz Extracelular/metabolismo , Neoplasias/metabolismo , Adhesión CelularRESUMEN
Mechanical ventilation (MV) is an essential life-saving technique, but prolonged MV can cause significant diaphragmatic dysfunction due to atrophy and decreased contractility of the diaphragm fibres, called ventilator-induced diaphragmatic dysfunction (VIDD). It is not clear about the mechanism of occurrence and prevention measures of VIDD. Irisin is a newly discovered muscle factor that regulates energy metabolism. Studies have shown that irisin can exhibit protective effects by downregulating endoplasmic reticulum (ER) stress in a variety of diseases; whether irisin plays a protective role in VIDD has not been reported. Sprague-Dawley rats were mechanically ventilated to construct a VIDD model, and intervention was performed by intravenous administration of irisin. Diaphragm contractility, degree of atrophy, cross-sectional areas (CSAs), ER stress markers, AMPK protein expression, oxidative stress indicators and apoptotic cell levels were measured at the end of the experiment.Our findings showed that as the duration of ventilation increased, the more severe the VIDD was, the degree of ER stress increased, and the expression of irisin decreased.ER stress may be one of the causes of VIDD. Intervention with irisin ameliorated VIDD by reducing the degree of ER stress, attenuating oxidative stress, and decreasing the apoptotic index. MV decreases the expression of phosphorylated AMPK in the diaphragm, whereas the use of irisin increases the expression of phosphorylated AMPK. Irisin may exert its protective effect by activating the phosphorylated AMPK pathway.