Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 5.834
Filtrar
1.
Cell Adh Migr ; 15(1): 261-271, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34494935

RESUMO

Serotonin is well known as a neurotransmitter. Its roles in neuronal processes such as learning, memory or cognition are well established, and also in disorders such as depression, schizophrenia, bipolar disorder, and dementia. However, its effects on adhesion and cytoskeletal remodelling which are strongly affected by 5-HT receptors, are not as well studied with some exceptions for e.g. platelet aggregation. Neuronal function is strongly dependent on cell-cell contacts and adhesion-related processes. Therefore the role played by serotonin in psychiatric illness, as well as in the positive and negative effects of neuropsychiatric drugs through cell-related adhesion can be of great significance. In this review, we explore the role of serotonin in some of these aspects based on recent findings.


Assuntos
Adesão Celular/fisiologia , Movimento Celular/fisiologia , Citoesqueleto/fisiologia , Neurotransmissores/fisiologia , Serotonina/fisiologia , Animais , Humanos , Transtornos Mentais/metabolismo
2.
Int J Mol Sci ; 22(16)2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34445693

RESUMO

Mechanical forces acting on cell-cell adhesion modulate the barrier function of endothelial cells. The actively remodeled actin cytoskeleton impinges on cell-cell adhesion to counteract external forces. We applied stress on endothelial monolayers by mechanical stretch to uncover the role of BRAF in the stress-induced response. Control cells responded to external forces by organizing and stabilizing actin cables in the stretched cell junctions. This was accompanied by an increase in intercellular gap formation, which was prevented in BRAF knockdown monolayers. In the absence of BRAF, there was excess stress fiber formation due to the enhanced reorganization of actin fibers. Our findings suggest that stretch-induced intercellular gap formation, leading to a decrease in barrier function of blood vessels, can be reverted by BRAF RNAi. This is important when the endothelium experiences changes in external stresses caused by high blood pressure, leading to edema, or by immune or cancer cells in inflammation or metastasis.


Assuntos
Células Endoteliais/metabolismo , Junções Comunicantes/fisiologia , Proteínas Proto-Oncogênicas B-raf/metabolismo , Actinas/fisiologia , Adesão Celular/fisiologia , Células Cultivadas , Citoesqueleto/fisiologia , Células Endoteliais/fisiologia , Endotélio Vascular/citologia , Humanos , Junções Intercelulares/fisiologia , Fenômenos Mecânicos , Proteínas Proto-Oncogênicas B-raf/fisiologia
3.
Elife ; 102021 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-34323216

RESUMO

Keratin intermediate filaments are an essential and major component of the cytoskeleton in epithelial cells. They form a stable yet dynamic filamentous network extending from the nucleus to the cell periphery, which provides resistance to mechanical stresses. Mutations in keratin genes are related to a variety of epithelial tissue diseases. Despite their importance, the molecular structure of keratin filaments remains largely unknown. In this study, we analyzed the structure of keratin 5/keratin 14 filaments within ghost mouse keratinocytes by cryo-electron microscopy and cryo-electron tomography. By averaging a large number of keratin segments, we have gained insights into the helical architecture of the filaments. Two-dimensional classification revealed profound variations in the diameter of keratin filaments and their subunit organization. Computational reconstitution of filaments of substantial length uncovered a high degree of internal heterogeneity along single filaments, which can contain regions of helical symmetry, regions with less symmetry and regions with significant diameter fluctuations. Cross-section views of filaments revealed that keratins form hollow cylinders consisting of multiple protofilaments, with an electron dense core located in the center of the filament. These findings shed light on the complex and remarkable heterogenic architecture of keratin filaments, suggesting that they are highly flexible, dynamic cytoskeletal structures.


Assuntos
Microscopia Crioeletrônica/métodos , Queratinas/análise , Queratinas/química , Animais , Citoesqueleto/fisiologia , Células Epiteliais/química , Filamentos Intermediários/ultraestrutura , Queratinócitos/ultraestrutura , Queratinas/classificação , Queratinas/ultraestrutura , Camundongos
4.
Nat Commun ; 12(1): 4470, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34294690

RESUMO

Gravity is a critical environmental factor regulating directional growth and morphogenesis in plants, and gravitropism is the process by which plants perceive and respond to the gravity vector. The cytoskeleton is proposed to play important roles in gravitropism, but the underlying mechanisms are obscure. Here we use genetic screening in Physcomitrella patens, to identify a locus GTRC, that when mutated, reverses the direction of protonemal gravitropism. GTRC encodes a processive minus-end-directed KCHb kinesin, and its N-terminal, C-terminal and motor domains are all essential for transducing the gravity signal. Chimeric analysis between GTRC/KCHb and KCHa reveal a unique role for the N-terminus of GTRC in gravitropism. Further study shows that gravity-triggered normal asymmetric distribution of actin filaments in the tip of protonema is dependent on GTRC. Thus, our work identifies a microtubule-based cellular motor that determines the direction of plant gravitropism via mediating the asymmetric distribution of actin filaments.


Assuntos
Bryopsida/fisiologia , Gravitropismo/fisiologia , Cinesina/fisiologia , Proteínas de Plantas/fisiologia , Citoesqueleto de Actina/química , Citoesqueleto de Actina/fisiologia , Sequência de Bases , Bryopsida/genética , Mapeamento Cromossômico , Citoesqueleto/química , Citoesqueleto/fisiologia , DNA de Plantas/genética , Genes de Plantas , Gravitropismo/genética , Cinesina/química , Cinesina/genética , Microtúbulos/química , Microtúbulos/fisiologia , Mutagênese , Mutação , Proteínas de Plantas/química , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Domínios Proteicos
5.
J Am Soc Nephrol ; 32(8): 1974-1986, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34078664

RESUMO

BACKGROUND: CKD is associated with the loss of functional nephr ons, leading to increased mechanical and metabolic stress in the remaining cells, particularly for cells constituting the filtration barrier, such as podocytes. The failure of podocytes to mount an adequate stress response can lead to further nephron loss and disease progression. However, the mechanisms that regulate this degenerative process in the kidney are unknown. METHODS: We combined in vitro, in vivo, and organ-on-chip approaches to identify the RE1-silencing transcription factor (REST), a repressor of neuronal genes during embryonic development, as a central regulator of podocyte adaptation to injury and aging. RESULTS: Mice with a specific deletion of REST in podocytes exhibit albuminuria, podocyte apoptosis, and glomerulosclerosis during aging, and exhibit increased vulnerability to renal injury. This phenotype is mediated, in part, by the effects of REST on the podocyte cytoskeleton that promote resistance to mechanical stressors and augment podocyte survival. Finally, REST expression is upregulated in human podocytes during aging, consistent with a conserved mechanism of stress resistance. CONCLUSIONS: These results suggest REST protects the kidney from injury and degeneration during aging, with potentially important therapeutic implications.


Assuntos
Adaptação Fisiológica/genética , Envelhecimento/fisiologia , Podócitos/patologia , Podócitos/fisiologia , Proteínas Repressoras/genética , Estresse Fisiológico/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Albuminúria/genética , Animais , Apoptose/genética , Linhagem Celular , Sobrevivência Celular , Citoesqueleto/fisiologia , Regulação da Expressão Gênica/genética , Homeostase/genética , Humanos , Camundongos , Fenótipo , Proteínas Repressoras/metabolismo , Esclerose , Adulto Jovem
6.
Int J Mol Sci ; 22(10)2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-34064719

RESUMO

Inflammation is a major cause of several chronic diseases and is reported to be recovered by the immuno-modulation of mesenchymal stem cells (MSCs). While most studies have focussed on the anti-inflammatory roles of MSCs in stem cell therapy, the impaired features of MSCs, such as the loss of homeostasis by systemic aging or pathologic conditions, remain incompletely understood. In this study, we investigated whether the altered phenotypes of human placenta-derived MSCs (hPD-MSCs) exposed to inflammatory cytokines, including TNF-α and IFN-γ, could be protected by MIT-001, a small anti-inflammatory and anti-necrotic molecule. MIT-001 promoted the spindle-like shape and cytoskeletal organization extending across the long cell axis, whereas hPD-MSCs exposed to TNF-α/IFN-γ exhibited increased morphological heterogeneity with an abnormal cell shape and cytoskeletal disorganization. Importantly, MIT-001 improved mitochondrial distribution across the cytoplasm. MIT-001 significantly reduced basal respiration, ATP production, and cellular ROS levels and augmented the spare respiratory capacity compared to TNF-α/IFN-γ-exposed hPD-MSCs, indicating enhanced mitochondrial quiescence and homeostasis. In conclusion, while TNF-α/IFN-γ-exposed MSCs lost homeostasis and mitochondrial quiescence by becoming over-activated in response to inflammatory cytokines, MIT-001 was able to rescue mitochondrial features and cellular phenotypes. Therefore, MIT-001 has therapeutic potential for clinical applications to treat mitochondrion-related inflammatory diseases.


Assuntos
Citoesqueleto/fisiologia , Células-Tronco Mesenquimais/fisiologia , Mitocôndrias/fisiologia , Compostos Orgânicos/farmacologia , Placenta/citologia , Citoesqueleto/efeitos dos fármacos , Feminino , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Consumo de Oxigênio , Placenta/efeitos dos fármacos , Placenta/metabolismo , Gravidez , Espécies Reativas de Oxigênio/metabolismo
7.
Cell Mol Life Sci ; 78(13): 5371-5379, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34085116

RESUMO

The identification of the membrane periodic skeleton (MPS), composed of a periodic lattice of actin rings interconnected by spectrin tetramers, was enabled by the development of super-resolution microscopy, and brought a new exciting perspective to our view of neuronal biology. This exquisite cytoskeleton arrangement plays an important role on mechanisms regulating neuronal (dys)function. The MPS was initially thought to provide mainly for axonal mechanical stability. Since its discovery, the importance of the MPS in multiple aspects of neuronal biology has, however, emerged. These comprise its capacity to act as a signaling platform, regulate axon diameter-with important consequences on the efficiency of axonal transport and electrophysiological properties- participate in the assembly and function of the axon initial segment, and control axon microtubule stability. Recently, MPS disassembly has also surfaced as an early player in the course of axon degeneration. Here, we will discuss the current knowledge on the role of the MPS in axonal physiology and disease.


Assuntos
Transporte Axonal , Axônios/fisiologia , Membrana Celular/metabolismo , Citoesqueleto/fisiologia , Espectrina/metabolismo , Animais , Humanos
8.
Dev Biol ; 477: 22-34, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34004181

RESUMO

Branching networks are a very common feature of multicellular animals and underlie the formation and function of numerous organs including the nervous system, the respiratory system, the vasculature and many internal glands. These networks range from subcellular structures such as dendritic trees to large multicellular tissues such as the lungs. The production of branched structures by single cells, so called subcellular branching, which has been better described in neurons and in cells of the respiratory and vascular systems, involves complex cytoskeletal remodelling events. In Drosophila, tracheal system terminal cells (TCs) and nervous system dendritic arborisation (da) neurons are good model systems for these subcellular branching processes. During development, the generation of subcellular branches by single-cells is characterized by extensive remodelling of the microtubule (MT) network and actin cytoskeleton, followed by vesicular transport and membrane dynamics. In this review, we describe the current knowledge on cytoskeletal regulation of subcellular branching, based on the terminal cells of the Drosophila tracheal system, but drawing parallels with dendritic branching and vertebrate vascular subcellular branching.


Assuntos
Diferenciação Celular/fisiologia , Citoesqueleto/fisiologia , Drosophila melanogaster/embriologia , Morfogênese , Neurogênese/fisiologia , Actinas/fisiologia , Animais , Comunicação Celular , Drosophila melanogaster/citologia , Endotélio/embriologia , Humanos , Microtúbulos/fisiologia , Análise de Célula Única , Traqueia/citologia , Traqueia/embriologia
9.
Exp Cell Res ; 405(1): 112662, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34022203

RESUMO

The cytoophidium, a filamentous structure formed by metabolic enzymes, has emerged as a novel regulatory machinery for certain proteins. The rate-limiting enzymes of de novo CTP and GTP synthesis, cytidine triphosphate synthase (CTPS) and inosine monophosphate dehydrogenase (IMPDH), are the most characterized cytoophidium-forming enzymes in mammalian models. Although the assembly of CTPS cytoophidia has been demonstrated in various organisms including multiple human cancers, a systemic survey for the presence of CTPS cytoophidia in mammalian tissues in normal physiological conditions has not yet been reported. Herein, we examine major organs of adult mouse and observe that CTPS cytoophidia are displayed by a specific thymocyte population ranging between DN3 to early DP stages. Most of these cytoophidium-presenting cells have both CTPS and IMPDH cytoophidia and undergo rapid cell proliferation. In addition, we show that cytoophidium formation is associated with active glycolytic metabolism as the cytoophidium-presenting cells exhibit higher levels of c-Myc, phospho-Akt and PFK. Inhibition of glycolysis with 2DG, however, disrupts most of cytoophidium structures and impairs cell proliferation. Our findings not only indicate that the regulation of CTPS and IMPDH cytoophidia are correlated with the metabolic switch triggered by pre-TCR signaling, but also suggest physiological roles of the cytoophidium in thymocyte development.


Assuntos
Carbono-Nitrogênio Ligases/metabolismo , Citidina Trifosfato/metabolismo , Citoesqueleto/fisiologia , IMP Desidrogenase/metabolismo , Timócitos/citologia , Animais , Proliferação de Células , Feminino , Masculino , Camundongos , Camundongos Endogâmicos ICR , Transdução de Sinais , Timócitos/metabolismo
10.
PLoS Comput Biol ; 17(5): e1008784, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33939706

RESUMO

The interior of a eukaryotic cell is a highly complex composite material which consists of water, structural scaffoldings, organelles, and various biomolecular solutes. All these components serve as obstacles that impede the motion of vesicles. Hence, it is hypothesized that any alteration of the cytoskeletal network may directly impact or even disrupt the vesicle transport. A disruption of the vesicle-mediated cell transport is thought to contribute to several severe diseases and disorders, such as diabetes, Parkinson's and Alzheimer's disease, emphasizing the clinical relevance. To address the outlined objective, a multiscale finite element model of the diffusive vesicle transport is proposed on the basis of the concept of homogenization, owed to the complexity of the cytoskeletal network. In order to study the microscopic effects of specific nanoscopic actin filament network alterations onto the vesicle transport, a parametrized three-dimensional geometrical model of the actin filament network was generated on the basis of experimentally observed filament densities and network geometries in an adenocarcinomic human alveolar basal epithelial cell. Numerical analyzes of the obtained effective diffusion properties within two-dimensional sampling domains of the whole cell model revealed that the computed homogenized diffusion coefficients can be predicted statistically accurate by a simple two-parameter power law as soon as the inaccessible area fraction, due to the obstacle geometries and the finite size of the vesicles, is known. This relationship, in turn, leads to a massive reduction in computation time and allows to study the impact of a variety of different cytoskeletal alterations onto the vesicle transport. Hence, the numerical simulations predicted a 35% increase in transport time due to a uniformly distributed four-fold increase of the total filament amount. On the other hand, a hypothetically reduced expression of filament cross-linking proteins led to sparser filament networks and, thus, a speed up of the vesicle transport.


Assuntos
Citoesqueleto de Actina/fisiologia , Citoesqueleto/fisiologia , Modelos Biológicos , Células A549 , Citoesqueleto de Actina/ultraestrutura , Anisotropia , Transporte Biológico , Biologia Computacional , Simulação por Computador , Citoesqueleto/ultraestrutura , Difusão , Análise de Elementos Finitos , Humanos , Conceitos Matemáticos , Movimento/fisiologia , Termodinâmica
11.
Nat Rev Mol Cell Biol ; 22(8): 548-562, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33927361

RESUMO

The cytoskeleton - comprising actin filaments, microtubules and intermediate filaments - serves instructive roles in regulating cell function and behaviour during development. However, a key challenge in cell and developmental biology is to dissect how these different structures function and interact in vivo to build complex tissues, with the ultimate aim to understand these processes in a mammalian organism. The preimplantation mouse embryo has emerged as a primary model system for tackling this challenge. Not only does the mouse embryo share many morphological similarities with the human embryo during its initial stages of life, it also permits the combination of genetic manipulations with live-imaging approaches to study cytoskeletal dynamics directly within an intact embryonic system. These advantages have led to the discovery of novel cytoskeletal structures and mechanisms controlling lineage specification, cell-cell communication and the establishment of the first forms of tissue architecture during development. Here we highlight the diverse organization and functions of each of the three cytoskeletal filaments during the key events that shape the early mammalian embryo, and discuss how they work together to perform key developmental tasks, including cell fate specification and morphogenesis of the blastocyst. Collectively, these findings are unveiling a new picture of how cells in the early embryo dynamically remodel their cytoskeleton with unique spatial and temporal precision to drive developmental processes in the rapidly changing in vivo environment.


Assuntos
Citoesqueleto/fisiologia , Desenvolvimento Embrionário/fisiologia , Animais , Blastocisto/citologia , Blastocisto/metabolismo , Comunicação Celular , Divisão Celular , Linhagem da Célula , Embrião de Mamíferos , Humanos , Morfogênese
12.
Biomolecules ; 11(5)2021 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-33922633

RESUMO

Metastasis is a process by which cancer cells escape from the location of the primary tumor invading normal tissues at distant organs. Chromosomal instability (CIN) is a hallmark of human cancer, associated with metastasis and therapeutic resistance. The centrosome plays a major role in organizing the microtubule cytoskeleton in animal cells regulating cellular architecture and cell division. Loss of centrosome integrity activates the p38-p53-p21 pathway, which results in cell-cycle arrest or senescence and acts as a cell-cycle checkpoint pathway. Structural and numerical centrosome abnormalities can lead to aneuploidy and CIN. New findings derived from studies on cancer and rare genetic disorders suggest that centrosome dysfunction alters the cellular microenvironment through Rho GTPases, p38, and JNK (c-Jun N-terminal Kinase)-dependent signaling in a way that is favorable for pro-invasive secretory phenotypes and aneuploidy tolerance. We here review recent data on how centrosomes act as complex molecular platforms for Rho GTPases and p38 MAPK (Mitogen activated kinase) signaling at the crossroads of CIN, cytoskeleton remodeling, and immune evasion via both cell-autonomous and non-autonomous mechanisms.


Assuntos
Centrossomo/metabolismo , Inflamação/patologia , Metástase Neoplásica/patologia , Aneuploidia , Animais , Ciclo Celular/fisiologia , Pontos de Checagem do Ciclo Celular/fisiologia , Centrossomo/fisiologia , Instabilidade Cromossômica/fisiologia , Citoesqueleto/fisiologia , Humanos , Inflamação/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/genética , Sistema de Sinalização das MAP Quinases/fisiologia , Microtúbulos/metabolismo , Metástase Neoplásica/genética , Neoplasias/metabolismo , Transdução de Sinais , Microambiente Tumoral , Proteína Supressora de Tumor p53/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/fisiologia , Proteínas rho de Ligação ao GTP/metabolismo
13.
Genes (Basel) ; 12(5)2021 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-33925685

RESUMO

Nuclear architecture undergoes an extensive remodeling during spermatogenesis, especially at levels of spermatocytes (SPC) and spermatids (SPT). Interestingly, typical events of spermiogenesis, such as nuclear elongation, acrosome biogenesis, and flagellum formation, need a functional cooperation between proteins of the nuclear envelope and acroplaxome/manchette structures. In addition, nuclear envelope plays a key role in chromosome distribution. In this scenario, special attention has been focused on the LINC (linker of nucleoskeleton and cytoskeleton) complex, a nuclear envelope-bridge structure involved in the connection of the nucleoskeleton to the cytoskeleton, governing mechanotransduction. It includes two integral proteins: KASH- and SUN-domain proteins, on the outer (ONM) and inner (INM) nuclear membrane, respectively. The LINC complex is involved in several functions fundamental to the correct development of sperm cells such as head formation and head to tail connection, and, therefore, it seems to be important in determining male fertility. This review provides a global overview of the main LINC complex components, with a special attention to their subcellular localization in sperm cells, their roles in the regulation of sperm morphological maturation, and, lastly, LINC complex alterations associated to male infertility.


Assuntos
Núcleo Celular/fisiologia , Citoesqueleto/metabolismo , Citoesqueleto/fisiologia , Membrana Nuclear/metabolismo , Matriz Nuclear/metabolismo , Espermatozoides/metabolismo , Espermatozoides/fisiologia , Animais , Núcleo Celular/metabolismo , Humanos , Infertilidade Masculina/metabolismo , Infertilidade Masculina/fisiopatologia , Masculino , Mecanotransdução Celular/fisiologia , Matriz Nuclear/fisiologia , Espermátides/metabolismo , Espermátides/fisiologia , Espermatócitos/metabolismo , Espermatócitos/fisiologia
14.
Nat Metab ; 3(4): 456-468, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33875882

RESUMO

Metabolism and mechanics are intrinsically intertwined. External forces, sensed through the cytoskeleton or distortion of the cell and organelles, induce metabolic changes in the cell. The resulting changes in metabolism, in turn, feed back to regulate every level of cell biology, including the mechanical properties of cells and tissues. Here we examine the links between metabolism and mechanics, highlighting signalling pathways involved in the regulation and response to cellular mechanosensing. We consider how forces and metabolism regulate one another through nanoscale molecular sensors, micrometre-scale cytoskeletal networks, organelles and dynamic biomolecular condensates. Understanding this cross-talk will create diagnostic and therapeutic opportunities for metabolic disorders such as cancer, cardiovascular pathologies and obesity.


Assuntos
Biologia Celular , Mecanotransdução Celular/fisiologia , Metabolismo/fisiologia , Animais , Citoesqueleto/fisiologia , Humanos , Transdução de Sinais , Estresse Mecânico
15.
J Cell Biol ; 220(6)2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-33764397

RESUMO

Ezrin, radixin, and moesin (ERM) family proteins regulate cytoskeletal responses by tethering the plasma membrane to the underlying actin cortex. Mutations in ERM proteins lead to severe combined immunodeficiency, but the function of these proteins in T cells remains poorly defined. Using mice in which T cells lack all ERM proteins, we demonstrate a selective role for these proteins in facilitating S1P-dependent egress from lymphoid organs. ERM-deficient T cells display defective S1P-induced migration in vitro, despite normal responses to standard protein chemokines. Analysis of these defects revealed that S1P promotes a fundamentally different mode of migration than chemokines, characterized by intracellular pressurization and bleb-based motility. ERM proteins facilitate this process, controlling directional migration by limiting blebbing to the leading edge. We propose that the distinct modes of motility induced by S1P and chemokines are specialized to allow T cell migration across lymphatic barriers and through tissue stroma, respectively.


Assuntos
Movimento Celular , Proteínas do Citoesqueleto/metabolismo , Proteínas do Citoesqueleto/fisiologia , Citoesqueleto/fisiologia , Linfócitos/metabolismo , Lisofosfolipídeos/metabolismo , Proteínas de Membrana/metabolismo , Proteínas dos Microfilamentos/metabolismo , Esfingosina/análogos & derivados , Animais , Membrana Celular , Proteínas do Citoesqueleto/genética , Feminino , Linfócitos/citologia , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas dos Microfilamentos/genética , Fosforilação , Esfingosina/metabolismo
16.
J Cell Mol Med ; 25(10): 4649-4657, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33742541

RESUMO

Although document studies (including ours) have been reported the achieved in vitro osteoclastic cellular model establishment from the RAW264.7 cell lineage, there was no study directly reported that American Type Culture Collection (ATCC) cell bank has various RAW264.7 cell lineages. Besides that, for our knowledge there was only one study compared the two different RAW264.7TIB-71 and RAW264.7CRL-2278 cell lineages for their osteoclastic differentiation, and they concluded that the RAW264.7CRL-2278 demonstrated to generate much osteoclast than RAW264.7TIB-71 . However, on the contrary to their results we noticed the fusion of RAW264.7TIB-71 in our previous studies was much compromising. Therefore, we try to explore the two cell lineages for their properties in osteoclastic differentiation with an in-depth cellular cytoskeletal study. Our current study has showed that comparing to the RAW264.7CRL-2278 , RAW264.7TIB-71 demonstrated a much higher efficacies for RANKL-stimulated osteoclastic differentiation. Besides that, in our depth cytoskeletal studies, we found that the RANKL-induced RAW264.7TIB-71 cells could finally differentiate into mature osteoclasts. However, regardless the various pre-treatment conditions, there was no mature osteoclast formed in RANKL-induced RAW264.7CRL-2278 cell lineage.


Assuntos
Diferenciação Celular , Proliferação de Células , Citoesqueleto/fisiologia , Osteoclastos/citologia , Ligante RANK/metabolismo , Animais , Camundongos , Osteoclastos/metabolismo , Ligante RANK/genética , Células RAW 264.7
17.
FASEB J ; 35(4): e21280, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33710673

RESUMO

Ethylene glycol butyl ether (EGBE) is a ubiquitous environmental pollutant that is commonly used in maquillage, industrial, and household products. EGBE has been shown to cause blood toxicity, carcinogenicity, and organ malformations. However, little is known about the impact of EGBE on the female reproductive system, especially oocyte quality. Here, we reported that EGBE influenced oocyte quality by showing the disturbed oocyte meiotic capacity, fertilization potential, and early embryonic development competency. Specifically, EGBE exposure impaired spindle/chromosome structure, microtubule stability, and actin polymerization to result in the oocyte maturation arrest and aneuploidy. In addition, EGBE exposure compromised the dynamics of cortical granules and their component ovastacin, leading to the failure of sperm binding and fertilization. Last, single-cell transcriptome analysis revealed that EGBE-induced oocyte deterioration was caused by mitochondrial dysfunction, which led to the accumulation of ROS and occurrence of apoptosis. Altogether, our study illustrates that mitochondrial dysfunction and redox perturbation is the major cause of the poor quality of oocytes exposed to EGBE.


Assuntos
Etilenoglicóis/toxicidade , Oócitos/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/fisiologia , Dano ao DNA , Desenvolvimento Embrionário/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Feminino , Meiose/efeitos dos fármacos , Camundongos , Organelas/efeitos dos fármacos , Organelas/fisiologia , Espécies Reativas de Oxigênio
18.
J Biol Chem ; 296: 100359, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33539927

RESUMO

Prion diseases are a group of neurodegenerative disorders that infect animals and humans with proteinaceous particles called prions. Prions consist of scrapie prion protein (PrPSc), a misfolded version of the cellular prion protein (PrPC). During disease progression, PrPSc replicates by interacting with PrPC and inducing its conversion to PrPSc. Attachment of PrPC to cellular membranes via a glycosylphosphatidylinositol (GPI) anchor is critical for the conversion of PrPC into PrPSc. However, the mechanisms governing PrPC conversion and replication on the membrane remain largely unclear. Here, a site-selectively modified PrP variant equipped with a fluorescent GPI anchor mimic (PrP-GPI) was employed to directly observe PrP at the cellular membrane in neuronal SH-SY5Y cells. PrP-GPI exhibits a cholesterol-dependent membrane accumulation and a cytoskeleton-dependent mobility. More specifically, inhibition of actin polymerization reduced the diffusion of PrP-GPI indicating protein clustering, which resembles the initial step of PrP aggregation and conversion into its pathogenic isoform. An intact actin cytoskeleton might therefore prevent conversion of PrPC into PrPSc and offer new therapeutic angles.


Assuntos
Citoesqueleto/fisiologia , Proteínas de Membrana/metabolismo , Príons/metabolismo , Actinas/metabolismo , Linhagem Celular , Membrana Celular/metabolismo , Análise por Conglomerados , Citoesqueleto/metabolismo , Glicosilfosfatidilinositóis/química , Glicosilfosfatidilinositóis/metabolismo , Humanos , Neurônios/metabolismo , Proteínas PrPSc/metabolismo , Doenças Priônicas/metabolismo , Proteínas Priônicas/metabolismo , Isoformas de Proteínas/metabolismo , Scrapie/metabolismo
19.
PLoS One ; 16(2): e0246311, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33524055

RESUMO

Amoeboid cell migration is characterized by frequent changes of the direction of motion and resembles a persistent random walk on long time scales. Although it is well known that cell migration is typically driven by the actin cytoskeleton, the cause of this migratory behavior remains poorly understood. We analyze the spontaneous dynamics of actin assembly due to nucleation promoting factors, where actin filaments lead to an inactivation of these factors. We show that this system exhibits excitable dynamics and can spontaneously generate waves, which we analyze in detail. By using a phase-field approach, we show that these waves can generate cellular random walks. We explore how the characteristics of these persistent random walks depend on the parameters governing the actin-nucleator dynamics. In particular, we find that the effective diffusion constant and the persistence time depend strongly on the speed of filament assembly and the rate of nucleator inactivation. Our findings point to a deterministic origin of the random walk behavior and suggest that cells could adapt their migration pattern by modifying the pool of available actin.


Assuntos
Actinas/fisiologia , Amoeba/fisiologia , Movimento Celular/fisiologia , Citoesqueleto/fisiologia , Modelos Teóricos
20.
Parasitol Res ; 120(3): 1067-1076, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33515065

RESUMO

Giardia intestinalis is a human parasite that causes a diarrheal disease in developing countries. G. intestinalis has a cytoskeleton (CSK) composed of microtubules and microfilaments, and the Giardia genome does not code for the canonical CSK-binding proteins described in other eukaryotic cells. To identify candidate actin and tubulin cross-linking proteins, we performed a BLAST analysis of the Giardia genome using a spectraplakins consensus sequence as a query. Based on the highest BLAST score, we selected a 259-kDa sequence designated as a cytoskeleton linker protein (CLP259). The sequence was cloned in three fragments and characterized by immunoprecipitation, confocal microscopy, and mass spectrometry (MS). CLP259 was located in the cytoplasm in the form of clusters of thick rods and colocalized with actin at numerous sites and with tubulin in the median body. Immunoprecipitation followed by mass spectrometry revealed that CLP259 interacts with structural proteins such as giardins, SALP-1, axonemal, and eight coiled-coils. The vesicular traffic proteins detected were Mu adaptin, Vacuolar ATP synthase subunit B, Bip, Sec61 alpha, NSF, AP complex subunit beta, and dynamin. These results indicate that CLP259 in trophozoites is a CSK linker protein for actin and tubulin and could act as a scaffold protein driving vesicular traffic.


Assuntos
Actinas/metabolismo , Giardia lamblia/metabolismo , Plaquinas/metabolismo , Tubulina (Proteína)/metabolismo , Actinas/química , Sequência de Aminoácidos , Animais , Anquirinas/química , Sequência de Bases , Western Blotting , Biologia Computacional , Sequência Consenso , Citoplasma/química , Citoesqueleto/química , Citoesqueleto/fisiologia , Citoesqueleto/ultraestrutura , Dinaminas/análise , Feminino , Imunofluorescência , Giardia lamblia/química , Giardia lamblia/ultraestrutura , Humanos , Imunoprecipitação , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Confocal , Plaquinas/química , Alinhamento de Sequência , Tubulina (Proteína)/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...