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1.
Mol Neurobiol ; 2024 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-39417922

RESUMEN

6:2 Fluorotelomer alcohol (6:2 FTOH) is a raw material used in the manufacture of short-chain poly- and perfluoroalkyl substances. Our previous study revealed that gestational exposure to 6:2 FTOH can impair blood‒brain barrier (BBB) function in offspring, accompanied by anxiety-like behavior and learning memory deficits. The aim of this study was to further investigate the specific mechanism by which maternal exposure to 6:2 FTOH resulted in impaired BBB function in offspring mice. Pregnant mice were orally administered different doses of 6:2 FTOH (0, 5, 25, and 125 mg/kg/day) from gestation day 8.5 until delivery. These results confirmed that maternal 6:2 FTOH exposure impaired BBB function and disrupted the brain immune microenvironment. Subsequent investigations revealed that endothelial-to-mesenchymal transition (EndMT) in the cerebral microvascular endothelium of offspring may be the mechanism mediating functional disruption of the BBB. Mechanistic studies revealed that exposure to 6:2 FTOH upregulated ETS proto-oncogene 1 (ETS1) expression via the tumor necrosis factor-α/extracellular signal-regulated kinase 1/2 signaling pathway, which mediated disturbances in energy metabolism, leading to impaired actin dynamics and subsequently triggering the EndMT phenotype. This is the first finding indicating that gestational 6:2 FTOH exposure caused functional impairment of the BBB through ETS1-mediated EndMT in cerebral microvascular endothelial cells, potentially providing novel insight into the environmental origins of neurodevelopmental disorders.

2.
Cell Commun Signal ; 22(1): 491, 2024 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-39394612

RESUMEN

Disulfidptosis is a novel discovered form of programmed cell death (PCD) that diverges from apoptosis, necroptosis, ferroptosis, and cuproptosis, stemming from disulfide stress-induced cytoskeletal collapse. In cancer cells exhibiting heightened expression of the solute carrier family 7 member 11 (SLC7A11), excessive cystine importation and reduction will deplete nicotinamide adenine dinucleotide phosphate (NADPH) under glucose deprivation, followed by an increase in intracellular disulfide stress and aberrant disulfide bond formation within actin networks, ultimately culminating in cytoskeletal collapse and disulfidptosis. Disulfidptosis involves crucial physiological processes in eukaryotic cells, such as cystine and glucose uptake, NADPH metabolism, and actin dynamics. The Rac1-WRC pathway-mediated actin polymerization is also implicated in this cell death due to its contribution to disulfide bond formation. However, the precise mechanisms underlying disulfidptosis and its role in tumors are not well understood. This is probably due to the multifaceted functionalities of SLC7A11 within cells and the complexities of the downstream pathways driving disulfidptosis. This review describes the critical roles of SLC7A11 in cells and summarizes recent research advancements in the potential pathways of disulfidptosis. Moreover, the less-studied aspects of this newly discovered cell death process are highlighted to stimulate further investigations in this field.


Asunto(s)
Citoesqueleto de Actina , Neoplasias , Humanos , Neoplasias/metabolismo , Neoplasias/patología , Neoplasias/tratamiento farmacológico , Citoesqueleto de Actina/metabolismo , Muerte Celular , Animales , Sistema de Transporte de Aminoácidos y+/metabolismo , Sistema de Transporte de Aminoácidos y+/genética
3.
FASEB J ; 38(18): e70055, 2024 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-39305126

RESUMEN

Spinal Muscular Atrophy (SMA) is a neuromuscular disease caused by low levels of the Survival of Motoneuron (SMN) protein. SMN interacts with and regulates the actin-binding protein profilin2a, thereby influencing actin dynamics. Dysfunctional actin dynamics caused by SMN loss disrupts neurite outgrowth, axonal pathfinding, and formation of functional synapses in neurons. Whether the SMN protein directly interacts with and regulates filamentous (F-) and monomeric globular (G-) actin is still elusive. In a quantitative single cell approach, we show that SMN loss leads to dysregulated F-/G-actin fractions. Furthermore, quantitative assessment of cell morphology suggests an F-actin organizational defect. Interestingly, this is mediated by an interaction of SMN with G- and F-actin. In co-immunoprecipitation, in-vitro pulldown and co-localization assays, we elucidated that this interaction is independent of the SMN-profilin2a interaction. Therefore, we suggest two populations being relevant for functional actin dynamics in healthy neurons: SMN-profilin2a-actin and SMN-actin. Additionally, those two populations may influence each other and therefore regulate binding of SMN to actin. In SMA, we showed a dysregulated co-localization pattern of SMN-actin which could only partially rescued by SMN restoration. However, dysregulation of F-/G-actin fractions was reduced by SMN restoration. Taken together, our results suggest a novel molecular function of SMN in binding to actin independent from SMN-profilin2a interaction.


Asunto(s)
Actinas , Atrofia Muscular Espinal , Profilinas , Proteína 1 para la Supervivencia de la Neurona Motora , Actinas/metabolismo , Profilinas/metabolismo , Profilinas/genética , Humanos , Atrofia Muscular Espinal/metabolismo , Atrofia Muscular Espinal/patología , Atrofia Muscular Espinal/genética , Animales , Proteína 1 para la Supervivencia de la Neurona Motora/metabolismo , Proteína 1 para la Supervivencia de la Neurona Motora/genética , Ratones , Neuronas Motoras/metabolismo , Unión Proteica
4.
Int J Mol Sci ; 25(16)2024 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-39201643

RESUMEN

An association between high CD47 expression and poor cancer survival has been attributed to its function on malignant cells to inhibit phagocytic clearance. However, CD47 mRNA expression in some cancers lacks correlation or correlates with improved survival. IFT57 encodes an essential primary cilium component and is colinear with CD47 across amniote genomes, suggesting coregulation of these genes. Analysis of The Cancer Genome Atlas datasets identified IFT57 as a top coexpressed gene with CD47 among 1156 human cancer cell lines and in most tumor types. The primary cilium also regulates cancer pathogenesis, and correlations between IFT57 mRNA and survival paralleled those for CD47 in thyroid and lung carcinomas, melanoma, and glioma. CD47 ranked first for coexpression with IFT57 mRNA in papillary thyroid carcinomas, and higher expression of both genes correlated with significantly improved overall survival. CD47 and IFT57 mRNAs were coordinately regulated in thyroid carcinoma cell lines. Transcriptome analysis following knockdown of CD47 or IFT57 in thyroid carcinoma cells identified the cytoskeletal regulator CRACD as a specific target of IFT57. CRACD mRNA expression inversely correlated with IFT57 mRNA and with survival in low-grade gliomas, lung adenocarcinomas, and papillary thyroid carcinomas, suggesting that IFT57 rather than CD47 regulates survival in these cancers.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Antígeno CD47 , Regulación Neoplásica de la Expresión Génica , Humanos , Antígeno CD47/genética , Antígeno CD47/metabolismo , Línea Celular Tumoral , Perfilación de la Expresión Génica , Neoplasias/genética , Neoplasias/mortalidad , Neoplasias/patología , Neoplasias/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Neoplasias de la Tiroides/genética , Neoplasias de la Tiroides/patología , Neoplasias de la Tiroides/mortalidad , Neoplasias de la Tiroides/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo
5.
J Neurochem ; 168(9): 3268-3283, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39126680

RESUMEN

Dynamins are large GTPases whose primary function is not only to catalyze membrane scission during endocytosis but also to modulate other cellular processes, such as actin polymerization and vesicle trafficking. Recently, we reported that centronuclear myopathy associated dynamin-2 mutations, p.A618T, and p.S619L, impair Ca2+-induced exocytosis of the glucose transporter GLUT4 containing vesicles in immortalized human myoblasts. As exocytosis and endocytosis occur within rapid timescales, here we applied high-temporal resolution techniques, such as patch-clamp capacitance measurements and carbon-fiber amperometry to assess the effects of these mutations on these two cellular processes, using bovine chromaffin cells as a study model. We found that the expression of any of these dynamin-2 mutants inhibits a dynamin and F-actin-dependent form of fast endocytosis triggered by single action potential stimulus, as well as inhibits a slow compensatory endocytosis induced by 500 ms square depolarization. Both dynamin-2 mutants further reduced the exocytosis induced by 500 ms depolarizations, and the frequency of release events and the recruitment of neuropeptide Y (NPY)-labeled vesicles to the cell cortex after stimulation of nicotinic acetylcholine receptors with 1,1-dimethyl-4-phenyl piperazine iodide (DMPP). They also provoked a significant decrease in the Ca2+-induced formation of new actin filaments in permeabilized chromaffin cells. In summary, our results indicate that the centronuclear myopathy (CNM)-linked p.A618T and p.S619L mutations in dynamin-2 affect exocytosis and endocytosis, being the disruption of F-actin dynamics a possible explanation for these results. These impaired cellular processes might underlie the pathogenic mechanisms associated with these mutations.


Asunto(s)
Células Cromafines , Dinamina II , Endocitosis , Exocitosis , Mutación , Miopatías Estructurales Congénitas , Células Cromafines/metabolismo , Endocitosis/fisiología , Endocitosis/genética , Dinamina II/genética , Dinamina II/metabolismo , Animales , Exocitosis/fisiología , Miopatías Estructurales Congénitas/genética , Miopatías Estructurales Congénitas/patología , Miopatías Estructurales Congénitas/metabolismo , Mutación/genética , Bovinos , Humanos , Actinas/metabolismo , Actinas/genética , Células Cultivadas , Técnicas de Placa-Clamp , Glándulas Suprarrenales/metabolismo , Glándulas Suprarrenales/patología
6.
Cells ; 13(13)2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38994946

RESUMEN

Although more difficult to detect than in the cytoplasm, it is now clear that actin polymerization occurs in the nucleus and that it plays a role in the specific processes of the nucleus such as transcription, replication, and DNA repair. A number of studies suggest that nuclear actin polymerization is promoting precise DNA repair by homologous recombination, which could potentially be of help for precise genome editing and gene therapy. This review summarizes the findings and describes the challenges and chances in the field.


Asunto(s)
Actinas , Núcleo Celular , Reparación del ADN , Terapia Genética , Polimerizacion , Humanos , Actinas/metabolismo , Núcleo Celular/metabolismo , Terapia Genética/métodos , Animales
7.
Autophagy ; 20(8): 1906-1908, 2024 08.
Artículo en Inglés | MEDLINE | ID: mdl-38855880

RESUMEN

The serine/threonine kinase, PINK1, and the E3 ubiquitin ligase, PRKN/Parkin facilitate LC3-dependent autophagosomal encasement and lysosomal clearance of dysfunctional mitochondria, and defects in this pathway contribute to the pathogenesis of numerous cardiometabolic and neurological diseases. Although dynamic actin remodeling has recently been shown to play an important role in governing spatiotemporal control of mitophagy, the mechanisms remain unclear. We recently found that the RhoGAP, ARHGAP26/GRAF1 is a PRKN-binding protein that is rapidly recruited to damaged mitochondria where upon phosphorylation by PINK1 it serves to coordinate phagophore capture by regulating mitochondrial-associated actin remodeling and by facilitating PRKN-LC3 interactions. Because ARHGAP26 phosphorylation on PINK1-dependent sites is dysregulated in human heart failure and ARHGAP26 depletion in mouse hearts blunts mitochondrial clearance and attenuates compensatory metabolic adaptations to stress, this enzyme may be a tractable target to treat the many diseases associated with mitochondrial dysfunction.


Asunto(s)
Actinas , Proteínas Activadoras de GTPasa , Mitocondrias , Animales , Humanos , Ratones , Actinas/metabolismo , Proteínas Activadoras de GTPasa/metabolismo , Mitocondrias/metabolismo , Mitofagia/fisiología , Proteínas Quinasas , Ubiquitina-Proteína Ligasas/metabolismo
8.
Bio Protoc ; 14(11): e4997, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38873016

RESUMEN

Cells need to migrate along gradients of chemicals (chemotaxis) in the course of development, wound healing, or immune responses. Neutrophils are prototypical migratory cells that are rapidly recruited to injured or infected tissues from the bloodstream. Their chemotaxis to these inflammatory sites involves changes in cytoskeletal dynamics in response to gradients of chemicals produced therein. Neutrophil chemotaxis has been largely studied in vitro; few assays have been developed to monitor gradient responses in complex living tissues. Here, we describe a laser-wound assay to generate focal injury in zebrafish larvae and monitor changes in behaviour and cytoskeletal dynamics. The first step is to cross adult fish and collect and rear embryos expressing a relevant fluorescent reporter (for example, Lifeact-mRuby, which labels dynamic actin) to an early larval stage. Subsequently, larvae are mounted and prepared for live imaging and wounding under a two-photon microscope. Finally, the resulting data are processed and used for cell segmentation and quantification of actin dynamics. Altogether, this assay allows the visualisation of cellular dynamics in response to acute injury at high resolution and can be combined with other manipulations, such as genetic or chemical perturbations. Key features • This protocol is designed to trigger laser wound in zebrafish larvae using two-photon intravital microscopy. • The ability to wound while imaging makes it possible to monitor the behaviour and actin changes of the cells immediately after gradient exposure. • The protocol requires a two-photon microscope for best results. Compared with one-photon laser wounding, the injury is more precise and has better tissue penetration. • The focal nature of the wounds is suitable for studies of neutrophil swarming/aggregation and can be further adapted to infectious settings.

9.
Int J Biol Sci ; 20(7): 2356-2369, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38725858

RESUMEN

Dysregulation of cancer cell motility is a key driver of invasion and metastasis. High dysadherin expression in cancer cells is correlated with invasion and metastasis. Here, we found the molecular mechanism by which dysadherin regulates the migration and invasion of colon cancer (CC). Comprehensive analysis using single-cell RNA sequencing data from CC patients revealed that high dysadherin expression in cells is linked to cell migration-related gene signatures. We confirmed that the deletion of dysadherin in tumor cells hindered local invasion and distant migration using in vivo tumor models. In this context, by performing cell morphological analysis, we found that aberrant cell migration resulted from impaired actin dynamics, focal adhesion turnover and protrusive structure formation upon dysadherin expression. Mechanistically, the activation of focal adhesion kinase (FAK) was observed in dysadherin-enriched cells. The dysadherin/FAK axis enhanced cell migration and invasion by activating the FAK downstream cascade, which includes the Rho family of small GTPases. Overall, this study illuminates the role of dysadherin in modulating cancer cell migration by forcing actin dynamics and protrusive structure formation via FAK signaling, indicating that targeting dysadherin may be a potential therapeutic strategy for CC patients.


Asunto(s)
Movimiento Celular , Neoplasias del Colon , Proteína-Tirosina Quinasas de Adhesión Focal , Canales Iónicos , Proteínas de Microfilamentos , Animales , Humanos , Ratones , Línea Celular Tumoral , Movimiento Celular/genética , Neoplasias del Colon/metabolismo , Neoplasias del Colon/patología , Neoplasias del Colon/genética , Quinasa 1 de Adhesión Focal/metabolismo , Quinasa 1 de Adhesión Focal/genética , Proteína-Tirosina Quinasas de Adhesión Focal/metabolismo , Canales Iónicos/metabolismo , Canales Iónicos/genética , Proteínas de Microfilamentos/metabolismo , Proteínas de Microfilamentos/genética , Transducción de Señal
10.
J Exp Bot ; 75(11): 3269-3286, 2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38600846

RESUMEN

The eukaryotic cytoskeleton is a complex scaffold consisting of actin filaments, intermediate filaments, and microtubules. Although fungi and plants lack intermediate filaments, their dynamic structural network of actin filaments and microtubules regulates cell shape, division, polarity, and vesicular trafficking. However, the specialized functions of the cytoskeleton during plant-fungus interactions remain elusive. Recent reports demonstrate that the plant cytoskeleton responds to signal cues and pathogen invasion through remodeling, thereby coordinating immune receptor trafficking, membrane microdomain formation, aggregation of organelles, and transport of defense compounds. Emerging evidence also suggests that cytoskeleton remodeling further regulates host immunity by triggering salicylic acid signaling, reactive oxygen species generation, and pathogenesis-related gene expression. During host invasion, fungi undergo systematic cytoskeleton remodeling, which is crucial for successful host penetration and colonization. Furthermore, phytohormones act as an essential regulator of plant cytoskeleton dynamics and are frequently targeted by fungal effectors to disrupt the host's growth-defense balance. This review discusses recent advances in the understanding of cytoskeleton dynamics during plant-fungus interactions and provides novel insights into the relationship between phytohormones and cytoskeleton remodeling upon pathogen attack. We also highlight the importance of fungal cytoskeleton rearrangements during host colonization and suggest directions for future investigations in this field.


Asunto(s)
Citoesqueleto , Hongos , Interacciones Huésped-Patógeno , Plantas , Citoesqueleto/metabolismo , Citoesqueleto/fisiología , Plantas/microbiología , Plantas/metabolismo , Plantas/inmunología , Interacciones Huésped-Patógeno/fisiología , Hongos/fisiología , Reguladores del Crecimiento de las Plantas/metabolismo , Reguladores del Crecimiento de las Plantas/fisiología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/inmunología
11.
Int J Mol Sci ; 25(8)2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38673765

RESUMEN

Quantum dots (QDs) are a novel type of nanomaterial that has unique optical and physical characteristics. As such, QDs are highly desired because of their potential to be used in both biomedical and industrial applications. However, the mass adoption of QDs usage has raised concerns among the scientific community regarding QDs' toxicity. Although many papers have reported the negative impact of QDs on a cellular level, the exact mechanism of the QDs' toxicity is still unclear. In this investigation, we study the adverse effects of QDs by focusing on one of the most important cellular processes: actin polymerization and depolymerization. Our results showed that QDs act in a biphasic manner where lower concentrations of QDs stimulate the polymerization of actin, while high concentrations of QDs inhibit actin polymerization. Furthermore, we found that QDs can bind to filamentous actin (F-actin) and cause bundling of the filament while also promoting actin depolymerization. Through this study, we found a novel mechanism in which QDs negatively influence cellular processes and exert toxicity.


Asunto(s)
Actinas , Compuestos de Cadmio , Puntos Cuánticos , Compuestos de Selenio , Sulfuros , Compuestos de Zinc , Puntos Cuánticos/química , Actinas/metabolismo , Compuestos de Zinc/química , Sulfuros/química , Compuestos de Cadmio/química , Compuestos de Selenio/química , Polimerizacion , Animales , Citoesqueleto de Actina/metabolismo , Citoesqueleto de Actina/efectos de los fármacos , Humanos
12.
Am J Respir Cell Mol Biol ; 70(6): 507-518, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38512807

RESUMEN

Airway remodeling is a cardinal feature of asthma, associated with increased airway smooth muscle (ASM) cell mass and upregulation of extracellular matrix deposition. Exaggerated ASM cell migration contributes to excessive ASM mass. Previously, we demonstrated the alleviating role of Kp (kisspeptin) receptor (KISS1R) activation by Kp-10 in mitogen (PDGF [platelet-derived growth factor])-induced human ASM cell proliferation in vitro and airway remodeling in vivo in a mouse model of asthma. Here, we examined the mechanisms by which KISS1R activation regulates mitogen-induced ASM cell migration. KISS1R activation using Kp-10 significantly inhibited PDGF-induced ASM cell migration, further confirmed using KISS1R shRNA. Furthermore, KISS1R activation modulated F/G actin dynamics and the expression of promigration proteins like CDC42 (cell division control protein 42) and cofilin. Mechanistically, we observed reduced ASM RhoA-GTPAse with KISS1R activation. The antimigratory effect of KISS1R was abolished by PKA (protein kinase A)-inhibitory peptide. Conversely, KISS1R activation significantly increased cAMP and phosphorylation of CREB (cAMP-response element binding protein) in PDGF-exposed ASM cells. Overall, these results highlight the alleviating properties of Kp-10 in the context of airway remodeling.


Asunto(s)
Movimiento Celular , Kisspeptinas , Miocitos del Músculo Liso , Receptores de Kisspeptina-1 , Transducción de Señal , Humanos , Factores Despolimerizantes de la Actina/metabolismo , Actinas/metabolismo , Remodelación de las Vías Aéreas (Respiratorias) , Proteína de Unión al GTP cdc42/metabolismo , Movimiento Celular/efectos de los fármacos , Proliferación Celular , Células Cultivadas , AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Kisspeptinas/metabolismo , Miocitos del Músculo Liso/metabolismo , Miocitos del Músculo Liso/efectos de los fármacos , Factor de Crecimiento Derivado de Plaquetas/metabolismo , Factor de Crecimiento Derivado de Plaquetas/farmacología , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Kisspeptina-1/metabolismo , Receptores de Kisspeptina-1/genética , Proteína de Unión al GTP rhoA/metabolismo
13.
Methods Mol Biol ; 2761: 245-255, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38427241

RESUMEN

Alzheimer's disease (AD) is distinguished by extracellular accumulation of amyloid-beta plaques and intracellular neurofibrillary tangles of Tau. Pathogenic Tau species are also known to display "prion-like propagation," which explains their presence in extracellular spaces as well. Glial population, especially microglia, tend to proclaim neuroinflammatory condition, disrupted signaling mechanisms, and cytoskeleton deregulation in AD. Omega-3 fatty acids play a neuroprotective role in the brain, which can trigger the anti-inflammatory pathways as well as actin dynamics in the cells. Improvement of cytoskeletal assembly mechanism by omega-3 fatty acids would regulate the other signaling cascades in the cells, leading to refining clearance of extracellular protein burden in AD. In this study, we focused on analyzing the ability of α-linolenic acid (ALA) as a regulator of actin dynamics to balance the signaling pathways in microglia, including endocytosis of extracellular Tau burden in AD.


Asunto(s)
Enfermedad de Alzheimer , Ácido alfa-Linolénico , Humanos , Ácido alfa-Linolénico/farmacología , Ácido alfa-Linolénico/metabolismo , Proteínas tau/metabolismo , Actinas/metabolismo , Microglía/metabolismo , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo
14.
Mol Cell Neurosci ; 129: 103921, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38428552

RESUMEN

Synapses change their weights in response to neuronal activity and in turn, neuronal networks alter their response properties and ultimately allow the brain to store information as memories. As for memories, not all events are maintained over time. Maintenance of synaptic plasticity depends on the interplay between functional changes at synapses and the synthesis of plasticity-related proteins that are involved in stabilizing the initial functional changes. Different forms of synaptic plasticity coexist in time and across the neuronal dendritic area. Thus, homosynaptic plasticity refers to activity-dependent synaptic modifications that are input-specific, whereas heterosynaptic plasticity relates to changes in non-activated synapses. Heterosynaptic forms of plasticity, such as synaptic cooperation and competition allow neurons to integrate events that occur separated by relatively large time windows, up to one hour. Here, we show that activation of Cdc42, a Rho GTPase that regulates actin cytoskeleton dynamics, is necessary for the maintenance of long-term potentiation (LTP) in a time-dependent manner. Inhibiting Cdc42 activation does not alter the time-course of LTP induction and its initial expression but blocks its late maintenance. We show that Cdc42 activation is involved in the phosphorylation of cofilin, a protein involved in modulating actin filaments and that weak and strong synaptic activation leads to similar levels on cofilin phosphorylation, despite different levels of LTP expression. We show that Cdc42 activation is required for synapses to interact by cooperation or competition, supporting the hypothesis that modulation of the actin cytoskeleton provides an activity-dependent and time-restricted permissive state of synapses allowing synaptic plasticity to occur. We found that under competition, the sequence in which synapses are activated determines the degree of LTP destabilization, demonstrating that competition is an active destabilization process. Taken together, we show that modulation of actin cytoskeleton by Cdc42 activation is necessary for the expression of homosynaptic and heterosynaptic forms of plasticity. Determining the temporal and spatial rules that determine whether synapses cooperate or compete will allow us to understand how memories are associated.


Asunto(s)
Potenciación a Largo Plazo , Sinapsis , Proteína de Unión al GTP cdc42 , Proteína de Unión al GTP cdc42/metabolismo , Animales , Potenciación a Largo Plazo/fisiología , Sinapsis/metabolismo , Sinapsis/fisiología , Fosforilación , Plasticidad Neuronal/fisiología , Ratas , Hipocampo/metabolismo , Hipocampo/fisiología , Hipocampo/citología , Factores Despolimerizantes de la Actina/metabolismo , Neuronas/metabolismo , Neuronas/fisiología , Masculino
15.
Dev Growth Differ ; 66(3): 205-218, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38403285

RESUMEN

Vision is formed by the transmission of light stimuli to the brain through axons extending from photoreceptor cells. Damage to these axons leads to loss of vision. Despite research on neural circuit regeneration through transplantation, achieving precise axon projection remains challenging. To achieve optic nerve regeneration by transplantation, we employed the Drosophila visual system. We previously established a transplantation method for Drosophila utilizing photoreceptor precursor cells extracted from the eye disc. However, little axonal elongation of transplanted cells into the brain, the lamina, was observed. We verified axonal elongation to the lamina by modifying the selection process for transplanted cells. Moreover, we focused on N-cadherin (Ncad), a cell adhesion factor, and Twinstar (Tsr), which has been shown to promote actin reorganization and induce axon elongation in damaged nerves. Overexpression of Ncad and tsr promoted axon elongation to the lamina, along with presynaptic structure formation in the elongating axons. Furthermore, overexpression of Neurexin-1 (Nrx-1), encoding a protein identified as a synaptic organizer, was found to not only promote presynapse formation but also enhance axon elongation. By introducing Ncad, tsr, and Nrx-1, we not only successfully achieved axonal projection of transplanted cells to the brain beyond the retina, but also confirmed the projection of transplanted cells into a deeper ganglion, the medulla. The present study offers valuable insights to realize regeneration through transplantation in a more complex nervous system.


Asunto(s)
Actinas , Adhesión Celular , Drosophila , Células Fotorreceptoras , Animales , Actinas/metabolismo , Axones/metabolismo , Drosophila/genética , Drosophila/metabolismo , Células Fotorreceptoras/metabolismo , Sinapsis/metabolismo
16.
Cell Oncol (Dordr) ; 47(4): 1071-1089, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38324230

RESUMEN

BACKGROUND: Metastasis accounts for the majority of cancer-related deaths. Actin dynamics and actin-based cell migration and invasion are important factors in cancer metastasis. Metastasis is characterized by actin polymerization and depolymerization, which are precisely regulated by molecular changes involving a plethora of actin regulators, including actin-binding proteins (ABPs) and signalling pathways, that enable cancer cell dissemination from the primary tumour. Research on deubiquitinating enzymes (DUBs) has revealed their vital roles in actin dynamics and actin-based migration and invasion during cancer metastasis. CONCLUSION: Here, we review how DUBs drive tumour metastasis by participating in actin rearrangement and actin-based migration and invasion. We summarize the well-characterized and essential actin cytoskeleton signalling molecules related to DUBs, including Rho GTPases, Src kinases, and ABPs such as cofilin and cortactin. Other DUBs that modulate actin-based migration signalling pathways are also discussed. Finally, we discuss and address therapeutic opportunities and ongoing challenges related to DUBs with respect to actin dynamics.


Asunto(s)
Citoesqueleto de Actina , Enzimas Desubicuitinizantes , Metástasis de la Neoplasia , Humanos , Citoesqueleto de Actina/metabolismo , Animales , Enzimas Desubicuitinizantes/metabolismo , Movimiento Celular , Transducción de Señal , Neoplasias/patología , Neoplasias/metabolismo , Neoplasias/enzimología , Actinas/metabolismo
17.
Food Sci Nutr ; 12(2): 881-889, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38370084

RESUMEN

Cucurbitacins have high economic value as they are a major source of food and have pharmacological properties. Cucurbitacin I (CuI) is a plant-derived natural tetracyclic triterpenoid compound that shows an anticancer effect via inhibiting the JAK2-STAT3 signaling pathway. The actin cytoskeleton is the most abundant protein in cells and regulates critical events through reorganization in cells. In this study, it is aimed at determining the direct effect of CuI on actin dynamics. The fluorescence profile of G-actin in the presence of CuI (1-200 nM) shifted to a higher temperature, suggesting that G-actin binds CuI and that G-actin-CuI is more thermally stable than the ligand-free form. CuI dose-dependently inhibited the polymerization of F-actin in vitro and disrupted actin filaments in endothelial cells. Docking and MD simulations suggested that CuI binds to the binding site formed by residues I136, I175, D154, and A138 that are at the interface of monomers in F-actin. The migration ability of cells treated with CuI for 24 h was significantly lower than the control group (p < .001). This study reveals the molecular mechanisms of CuI in the regulation of actin dynamics by binding G-actin. More importantly, this study indicates a novel role of CuI as an actin-targeting drug by binding directly to G-actin and may contribute to the mode of action of CuI on anticancer activities.

18.
Biochem Soc Trans ; 52(1): 343-352, 2024 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-38288872

RESUMEN

The Arp2/3 complex, which generates both branched but also linear actin filaments via activation of SPIN90, is evolutionarily conserved in eukaryotes. Several factors regulate the stability of filaments generated by the Arp2/3 complex to maintain the dynamics and architecture of actin networks. In this review, we summarise recent studies on the molecular mechanisms governing the tuning of Arp2/3 complex nucleated actin filaments, which includes investigations using microfluidics and single-molecule imaging to reveal the mechanosensitivity, dissociation and regeneration of actin branches. We also discuss the high-resolution cryo-EM structure of cortactin bound to actin branches, as well as the differences and similarities between the stability of Arp2/3 complex nucleated branches and linear filaments. These new studies provide a clearer picture of the stabilisation of Arp2/3 nucleated filaments at the molecular level. We also identified gaps in our understanding of how different factors collectively contribute to the stabilisation of Arp2/3 complex-generated actin networks.


Asunto(s)
Complejo 2-3 Proteico Relacionado con la Actina , Actinas , Complejo 2-3 Proteico Relacionado con la Actina/análisis , Complejo 2-3 Proteico Relacionado con la Actina/metabolismo , Actinas/metabolismo , Citoesqueleto de Actina/metabolismo , Citoesqueleto/metabolismo
19.
Plant Biotechnol J ; 22(1): 98-115, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37688588

RESUMEN

As a multifunctional hormone-like molecule, melatonin exhibits a pleiotropic role in plant salt stress tolerance. While actin cytoskeleton is essential to plant tolerance to salt stress, it is unclear if and how actin cytoskeleton participates in the melatonin-mediated alleviation of plant salt stress. Here, we report that melatonin alleviates salt stress damage in pigeon pea by activating a kinase-like protein, which interacts with an actin-depolymerizing factor. Cajanus cajan Actin-Depolymerizing Factor 9 (CcADF9) has the function of severing actin filaments and is highly expressed under salt stress. The CcADF9 overexpression lines (CcADF9-OE) showed a reduction of transgenic root length and an increased sensitivity to salt stress. By using CcADF9 as a bait to screen an Y2H library, we identified actin depolymerizing factor-related phosphokinase 1 (ARP1), a novel protein kinase that interacts with CcADF9. CcARP1, induced by melatonin, promotes salt resistance of pigeon pea through phosphorylating CcADF9, inhibiting its severing activity. The CcARP1 overexpression lines (CcARP1-OE) displayed an increased transgenic root length and resistance to salt stress, whereas CcARP1 RNA interference lines (CcARP1-RNAi) presented the opposite phenotype. Altogether, our findings reveal that melatonin-induced CcARP1 maintains F-actin dynamics balance by phosphorylating CcADF9, thereby promoting root growth and enhancing salt tolerance.


Asunto(s)
Cajanus , Melatonina , Melatonina/farmacología , Melatonina/metabolismo , Actinas/metabolismo , Cajanus/genética , Destrina/metabolismo , Tolerancia a la Sal/genética , Fosforilación , Citoesqueleto de Actina/metabolismo
20.
Mol Cell Endocrinol ; 579: 112087, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-37827228

RESUMEN

Sex-steroid signaling, especially estrogen, has a paradoxical impact on regulating airway remodeling. In our previous studies, we demonstrated differential effects of 17ß-estradiol (E2) towards estrogen receptors (ERs: α and ß) in regulating airway smooth muscle (ASM) cell proliferation and extracellular matrix (ECM) production. However, the role of ERs and their signaling on ASM migration is still unexplored. In this study, we examined how ERα versus ERß affects the mitogen (Platelet-derived growth factor, PDGF)-induced human ASM cell migration as well as the underlying mechanisms involved. We used Lionheart-FX automated microscopy and transwell assays to measure cell migration and found that activating specific ERs had differential effects on PDGF-induced ASM cell migration. Pharmacological activation of ERß or shRNA mediated knockdown of ERα and specific activation of ERß blunted PDGF-induced cell migration. Furthermore, specific ERß activation showed inhibition of actin polymerization by reducing the F/G-actin ratio. Using Zeiss confocal microscopy coupled with three-dimensional algorithmic ZEN-image analysis showed an ERß-mediated reduction in PDGF-induced expressions of neural Wiskott-Aldrich syndrome protein (N-WASP) and actin-related proteins-2/3 (Arp2/3) complex, thereby inhibiting actin-branching and lamellipodia. In addition, ERß activation also reduces the clustering of actin-binding proteins (vinculin and paxillin) at the leading edge of ASM cells. However, cells treated with E2 or ERα agonists do not show significant changes in actin/lamellipodial dynamics. Overall, these findings unveil the significance of ERß activation in regulating lamellipodial and focal adhesion dynamics to regulate ASM cell migration and could be a novel target to blunt airway remodeling.


Asunto(s)
Receptor alfa de Estrógeno , Receptores de Estrógenos , Humanos , Receptores de Estrógenos/metabolismo , Receptor alfa de Estrógeno/metabolismo , Actinas/metabolismo , Receptor beta de Estrógeno/genética , Receptor beta de Estrógeno/metabolismo , Adhesiones Focales/metabolismo , Seudópodos/metabolismo , Remodelación de las Vías Aéreas (Respiratorias)/fisiología , Movimiento Celular , Miocitos del Músculo Liso/metabolismo , Factor de Crecimiento Derivado de Plaquetas/farmacología
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