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1.
Nat Commun ; 11(1): 539, 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-31988277

RESUMO

In the Caenorhabditis elegans zygote, PAR protein patterns, driven by mutual anatagonism, determine the anterior-posterior axis and facilitate the redistribution of proteins for the first cell division. Yet, the factors that determine the selection of the polarity axis remain unclear. We present a reaction-diffusion model in realistic cell geometry, based on biomolecular reactions and accounting for the coupling between membrane and cytosolic dynamics. We find that the kinetics of the phosphorylation-dephosphorylation cycle of PARs and the diffusive protein fluxes from the cytosol towards the membrane are crucial for the robust selection of the anterior-posterior axis for polarisation. The local ratio of membrane surface to cytosolic volume is the main geometric cue that initiates pattern formation, while the choice of the long-axis for polarisation is largely determined by the length of the aPAR-pPAR interface, and mediated by processes that minimise the diffusive fluxes of PAR proteins between cytosol and membrane.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Polaridade Celular , Animais , Divisão Celular Assimétrica , Caenorhabditis elegans/citologia , Caenorhabditis elegans/embriologia , Biologia Computacional , Citosol/metabolismo , Embrião não Mamífero/citologia , Embrião não Mamífero/metabolismo , Desenvolvimento Embrionário , Cinética , Modelos Biológicos , Fosforilação , Transdução de Sinais , Termodinâmica
2.
mSphere ; 5(1)2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31996420

RESUMO

Toxoplasma gondii can infect and replicate in vascular endothelial cells prior to entering host tissues. However, little is known about the molecular interactions at the parasite-endothelial cell interface. We demonstrate that T. gondii infection of primary human umbilical vein endothelial cells (HUVEC) altered cell morphology and dysregulated barrier function, increasing permeability to low-molecular-weight polymers. T. gondii disrupted vascular endothelial cadherin (VE-cadherin) and ß-catenin localization to the cell periphery and reduced VE-cadherin protein expression. Notably, T. gondii infection led to reorganization of the host cytoskeleton by reducing filamentous actin (F-actin) stress fiber abundance under static and microfluidic shear stress conditions and by reducing planar cell polarity. RNA sequencing (RNA-Seq) comparing genome-wide transcriptional profiles of infected to uninfected endothelial cells revealed changes in gene expression associated with cell-cell adhesion, extracellular matrix reorganization, and cytokine-mediated signaling. In particular, genes downstream of Hippo signaling and the biomechanical sensor and transcriptional coactivator Yes-associated protein (YAP) were downregulated in infected endothelial cells. Interestingly, T. gondii infection activated Hippo signaling by increasing phosphorylation of LATS1, leading to cytoplasmic retention of YAP, and reducing YAP target gene expression. These findings suggest that T. gondii infection triggers Hippo signaling and YAP nuclear export, leading to an altered transcriptional profile of infected endothelial cells.IMPORTANCE Toxoplasma gondii is a foodborne parasite that infects virtually all warm-blooded animals and can cause severe disease in individuals with compromised or weakened immune systems. During dissemination in its infected hosts, T. gondii breaches endothelial barriers to enter tissues and establish the chronic infections underlying the most severe manifestations of toxoplasmosis. The research presented here examines how T. gondii infection of primary human endothelial cells induces changes in cell morphology, barrier function, gene expression, and mechanotransduction signaling under static conditions and under the physiological conditions of shear stress found in the bloodstream. Understanding the molecular interactions occurring at the interface between endothelial cells and T. gondii may provide insights into processes linked to parasite dissemination and pathogenesis.


Assuntos
Permeabilidade da Membrana Celular , Células Endoteliais da Veia Umbilical Humana/parasitologia , Mecanotransdução Celular , Toxoplasma/patogenicidade , Actinas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Antígenos CD/metabolismo , Caderinas/metabolismo , Polaridade Celular , Células Cultivadas , Citoesqueleto , Células Endoteliais da Veia Umbilical Humana/citologia , Humanos , Proteínas Serina-Treonina Quinases/metabolismo , Fibras de Estresse/metabolismo , Fatores de Transcrição/metabolismo , Transcriptoma , beta Catenina/metabolismo
3.
Dev Cell ; 52(2): 137-138, 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-31991102

RESUMO

Plant cells use polarity cues to confine membrane proteins to specific localizations. In this issue of Developmental Cell, Marhava et al. (2020) describe a biochemical feedforward mechanism that reinforces polar protein localization and regulates membrane composition and endocytosis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Polaridade Celular/fisiologia , Endocitose/fisiologia , Modelos Biológicos , Fosforilação/fisiologia , Fenômenos Fisiológicos Vegetais
4.
Int J Cancer ; 146(6): 1578-1591, 2020 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-31577845

RESUMO

Breast cancer remains a leading cause of cancer-related death for women. The stepwise development of breast cancer through preinvasive to invasive disease is associated with progressive disruption of cellular and tissue organization. Apical-basal polarity is thought to be a barrier to breast cancer development, but the extent and potential mechanisms that contribute to disrupted polarity are incompletely understood. To investigate the cell polarity status of invasive breast cancers, we performed multiplex imaging of polarity markers on tissue cores from 432 patients from a spectrum of grades, stages and molecular subtypes. Apical-basal cell polarity was lost in 100% of cells in all cases studied, indicating that loss of epithelial polarity may be a universal feature of invasive breast cancer. We then analyzed genomic events from the TCGA dataset for an 18-gene set of core polarity genes. Coamplification of polarity genes with established breast oncogenes was found, which is consistent with functional cooperation within signaling amplicons. Gene-expression levels of several polarity genes were significantly associated with survival, and protein localization of Par6 correlated with higher grade, nodal metastasis and molecular subtype. Finally, multiple hotspot mutations in protein-protein interaction domains critical for cell polarity were identified. Our data indicate that genomic events likely contribute to pervasive disruption of epithelial polarity observed in invasive breast cancer.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias da Mama/patologia , Polaridade Celular/genética , Células Epiteliais/patologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/análise , Mama/patologia , Neoplasias da Mama/genética , Neoplasias da Mama/mortalidade , Variações do Número de Cópias de DNA , Conjuntos de Dados como Assunto , Intervalo Livre de Doença , Feminino , Perfilação da Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , Pessoa de Meia-Idade , Imagem Molecular , Mutação , Invasividade Neoplásica/genética , Domínios e Motivos de Interação entre Proteínas/genética , Transdução de Sinais/genética , Análise Serial de Tecidos
5.
Life Sci ; 240: 116985, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31647949

RESUMO

BACKGROUND: The infiltration and activation of macrophages play key roles in arterial restenosis, providing a promising strategy for the treatment of restenosis caused by intimal hyperplasia. Although miR-150 has been implicated in cardiovascular diseases, the individual effect of miR-150 on intimal hyperplasia remains unclear. METHODS AND RESULTS: We observed that the expression of miR-150 was robustly reduced in proinflammatory M1 macrophages and reversely induced in resolving M2 macrophages. An in vitro experiment demonstrated that miR-150 deficiency promoted extensive upregulation of the expression of M1 markers but attenuated the expression of M2 macrophage markers. MiR-150 enhanced the proliferation and migration of vascular smooth muscle cells (VSMCs) when co-cultured with conditioned medium from polarized macrophages upon LPS or IL-4 stimulation. Mechanistically, the bioinformatics analysis and luciferase assay results showed that miR-150 directly targeted STAT1 and STAT1 was required for the effect of miR-150 knockout on macrophage polarization. More importantly, we showed that knockout of miR-150 accelerated neointima formation, accompanied by the activation of M1 macrophages and the inactivation of M2 macrophages. Furthermore, miR-150 deficiency in marrow-derived cell accelerated neointima formation. CONCLUSION: Our research demonstrated that miR-150 deficiency promoted intimal hyperplasia with high ratios of M1 to M2 macrophages and subsequently increased VSMCs proliferation and migration, which were partially mediated by directly targeting to STAT1. Collectively, these results suggested that miR-150 may act as a novel therapeutic target for arterial restenosis.


Assuntos
Polaridade Celular/genética , Hiperplasia/genética , Macrófagos , MicroRNAs/genética , Neointima/genética , Animais , Movimento Celular/genética , Proliferação de Células , Biologia Computacional , Hiperplasia/patologia , Inflamação/genética , Inflamação/patologia , Interleucina-4/farmacologia , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , Camundongos Knockout , Músculo Liso Vascular , Neointima/patologia , Fator de Transcrição STAT1/genética
6.
J Biochem Mol Toxicol ; 34(2): e22422, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31729780

RESUMO

M1 macrophages serve one edge as proinflammatory and M2 macrophages serve the other edge as an anti-inflammatory macrophage. It appears that a related "switch" in macrophage morphology may also happen in the course of atherosclerosis, which has not yet been elucidated. An atherogenic diet (AD) was given to rats, and induction of macrophage differentiation and the nuclear localization of nuclear factor-kappa B (NFκB) were investigated by Western blot and immunofluorescence. Chemokines were analyzed using an antibody array with 32 target proteins. M2 macrophage transformation was confirmed in diosgenin-treated aorta by immunofluorescence and was validated in vitro using THP-1 cells. MAC387 (macrophage marker) and NFκBp65 (inflammatory hub) were upregulated in oxidatively-modified low-density lipoprotein (OxyLDL) and AD-induced condition. Macrophage differentiation, which induced the formation of inflammatory mediators, was not significantly suppressed by the inhibition of NFκB using dexamethasone. M1 macrophage polarization was identified in OxyLDL-induced monocytes, which are proinflammatory in nature, whereas M2 macrophage polarization was noticed in diosgenin-treated monocytes, which exhibit anti-inflammatory properties. M1-and M2-specific chemokines were analyzed using chemokine antibody array. Furthermore, the expression of proinflammatory macrophage (M1) was noticed in AD-induced aorta and anti-inflammatory macrophage (M2) was observed in diosgenin-treated aorta. This is the first report where, unifying the mechanism of diosgenin as aan nti-atherosclerotic and the expression of M1 and M2 specific chemokines is shown by downregulating NFκB and not by preventing the differentiation of monocyte into a macrophage, but by allowing macrophage to differentiate into M2, which aids in preventing the atherosclerotic progression.


Assuntos
Aorta/metabolismo , Aterosclerose/metabolismo , Polaridade Celular , Citocinas/metabolismo , Diosgenina/farmacologia , Macrófagos/metabolismo , Extratos Vegetais/farmacologia , Fator de Transcrição RelA/metabolismo , Animais , Antígenos CD/genética , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/genética , Antígenos de Diferenciação Mielomonocítica/metabolismo , Aterosclerose/tratamento farmacológico , Aterosclerose/prevenção & controle , Antígenos CD36/genética , Antígenos CD36/metabolismo , Diferenciação Celular/efeitos dos fármacos , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Dexametasona/farmacologia , Dieta Aterogênica/efeitos adversos , Dioscorea/química , Diosgenina/uso terapêutico , Humanos , Lipoproteínas LDL/farmacologia , Masculino , Monócitos/metabolismo , Extratos Vegetais/uso terapêutico , Ratos , Transdução de Sinais/efeitos dos fármacos , Células THP-1 , Fator de Transcrição RelA/antagonistas & inibidores , Fator de Transcrição RelA/genética
7.
Phys Rev Lett ; 123(21): 218101, 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31809131

RESUMO

We develop an iterated map model to describe the bifurcations and complex dynamics caused by the feedback between voltage and intracellular Ca^{2+} and Na^{+} concentrations in paced ventricular myocytes. Voltage and Ca^{2+} can form either a positive or a negative feedback loop, while voltage and Na^{+} form a negative feedback loop. Under certain diseased conditions, when the feedback between voltage and Ca^{2+} is positive, Hopf bifurcations occur, leading to periodic oscillatory behaviors. When this feedback is negative, period-doubling bifurcation routes to alternans and chaos occur.


Assuntos
Cálcio/metabolismo , Modelos Cardiovasculares , Miócitos Cardíacos/metabolismo , Sódio/metabolismo , Relógios Biológicos , Cátions Bivalentes/metabolismo , Cátions Monovalentes/metabolismo , Membrana Celular/metabolismo , Polaridade Celular , Retroalimentação Fisiológica , Ventrículos do Coração/citologia , Ventrículos do Coração/metabolismo , Potenciais da Membrana , Miócitos Cardíacos/citologia , Trocador de Sódio e Cálcio/metabolismo
8.
Int J Nanomedicine ; 14: 9325-9336, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31819434

RESUMO

Background: During the past few years, immune cell therapy for malignant cancer has benefited a considerable amount of patients worldwide. As one of several promising candidates for immunotherapy, Vγ9Vδ2 γδ T cells have many unique biological advantages, such as non-MHC restriction and have been noted as the earliest source of IFN-γ. However, potentiating anti-tumor functions of γδ T cells has become of particular interest to researchers studying γδ T cell applications. Purpose: In this study, we proposed a nanotechnology-based methodology for strengthening γδ T cell functions. Methods: As a type of reliable, biocompatible material, chitosan nanoparticles (CSNPs) were used to enhance anti-tumor immunity of γδ T cells. Results: First, we found that the size of prepared CSNPs distributed 50 to 100 nm, and that CSNPs had optimal immunocompatibility. Then, we observed that CSNPs could induce α-tubulin cytoskeleton polarization and rearrangement, correlating with a higher killing ability of γδ T cells. Furthermore, we revealed that CSNPs could enhance Vγ9Vδ2 T cell anti-tumor functions by upregulating killing of related receptors, including NKG2D, CD56, FasL, and perforin secretion. Conclusion: Our work provided evidence of application for CSNPs based bio-carrier in immunotherapy. More importantly, we proposed a new strategy for enhancing γδ T cell anti-tumor activity using nanobiomaterial, which could benefit future clinical applications of γδ T cells.


Assuntos
Quitosana/farmacologia , Citoesqueleto/metabolismo , Nanopartículas/química , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Linfócitos T Citotóxicos/imunologia , Regulação para Cima , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Polaridade Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Citoesqueleto/efeitos dos fármacos , Citotoxicidade Imunológica/efeitos dos fármacos , Humanos , Ativação Linfocitária , Nanopartículas/ultraestrutura , Perforina/metabolismo , Tubulina (Proteína)/metabolismo
9.
Int J Nanomedicine ; 14: 9361-9375, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31819437

RESUMO

Background: Rehmannia glutinosa polysaccharide is the main reason that contributes to the immunological function of R. glutinosa. Due to its disadvantages in clinical use, here we designed the PEGylation nano-RGP (pRL) to improve the drug-targeting effect and the immunological function. Our present work aims to establish the optimum condition of preparing the pRL and to investigate its immunological function on macrophages. Methods: pRL was prepared by thin film hydration method combined with ultra-sonication technique. And its preparation conditions were optimized with response surface methodology. Also, the lyophilization method was optimized. The characteristics of the pRL were evaluated, including particle size, drug loading, encapsulation efficiency and morphology. The immunological function of pRL on macrophage was investigated through CCK-8 test, ELISA and flow cytometry. Results: The lipid-to-cholesterol molar ratio of 8:1, the addition of DSPE-PEG2000 of 9% and the lipid-to-drug ratio of 5.4:1 were the optimum preparation technology for pRL. The encapsulation efficiency (EE) of pRL under this preparation technology was 95.81±1.58%, with a particle size of 31.98 ± 2.6 nm. The lactose-to-lipid ratio (2:1) was the optimal lyophilization method. pRL promoted macrophage proliferation, which is significantly better than that of nano-RGP without PEGylation (RL). pRL-stimulated RAW264.7 cells showed a high secretion of pro-inflammatory cytokines, which is the characteristic indicator of M1 polarization. Enhanced cellular uptake through macropinocytosis-dependent and caveolae-mediated endocytosis was observed in pRL-treated RAW264.7 cells. Conclusion: Our study concluded that PEGylation effectively overcame the poor targeting effect of Rehmannia glutinosa polysaccharide (RGP) and significantly improved the immunological profile of its nano-formulation, which suggested that pRL could serve as an immune adjuvant in clinical application.


Assuntos
Adjuvantes Imunológicos/farmacologia , Macrófagos/imunologia , Nanopartículas/química , Polietilenoglicóis/química , Polissacarídeos/farmacologia , Rehmannia/química , Análise de Variância , Animais , Cavéolas/efeitos dos fármacos , Cavéolas/metabolismo , Polaridade Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Citocinas/biossíntese , Liofilização , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Camundongos , Pinocitose/efeitos dos fármacos , Células RAW 264.7
10.
PLoS Comput Biol ; 15(12): e1007171, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31869321

RESUMO

Pseudostratified epithelia (PSE) are a common type of columnar epithelia found in a wealth of embryonic and adult tissues such as ectodermal placodes, the trachea, the ureter, the gut and the neuroepithelium. PSE are characterized by the choreographed displacement of cells' nuclei along the apicobasal axis according to phases of their cell cycle. Such movements, called interkinetic movements (INM), have been proposed to influence tissue expansion and shape and suggested as culprit in several congenital diseases such as CAKUT (Congenital anomalies of kidney and urinary tract) and esophageal atresia. INM rely on cytoskeleton dynamics just as adhesion, contractility and mitosis do. Therefore, long term impairment of INM without affecting proliferation and adhesion is currently technically unachievable. Here we bypassed this hurdle by generating a 2D agent-based model of a proliferating PSE and compared its output to the growth of the chick neuroepithelium to assess the interplay between INM and these other important cell processes during growth of a PSE. We found that INM directly generates apical expansion and apical nuclear crowding. In addition, our data strongly suggest that apicobasal elongation of cells is not an emerging property of a proliferative PSE but rather requires a specific elongation program. We then discuss how such program might functionally link INM, tissue growth and differentiation.


Assuntos
Núcleo Celular/fisiologia , Epitélio/embriologia , Animais , Padronização Corporal/fisiologia , Contagem de Células , Ciclo Celular/fisiologia , Polaridade Celular/fisiologia , Proliferação de Células/fisiologia , Embrião de Galinha , Biologia Computacional , Humanos , Modelos Biológicos , Movimento/fisiologia , Células Neuroepiteliais/citologia , Análise de Sistemas , Anormalidades Urogenitais/embriologia , Refluxo Vesicoureteral/embriologia
11.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 35(11): 967-972, 2019 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-31878991

RESUMO

Objective To examine the effect of exosomes derived from lung adenocarcinoma cells on macrophage polarization and the change of cytobiological behaviors in lung cancer cells induced by activated macrophages. Methods Exosomes derived from lung adenocarcinoma cells were extracted by exosomes extraction kit. The expression of exosomal markers including CD9 and CD63 was detected by Western blot analysis. After THP-1 cells were treated with 100 ng/mL phorbol ester (PMA) for 48 hours, the macrophage marker of CD68 was detected by real-time quantitative PCR (RT-qPCR). Following 24-hour treatment of macrophages with the exosomes (200 µg/mL), the mRNA levels of transforming growth factor ß (TGF-ß), tumor necrosis factor α (TNF-α), inducible nitric oxide synthase (iNOS) and CD163 were detected by RT-qPCR, and the protein levels of IL-6, IL-8 and IL-10 were measured by IMMULITE 1000. The macrophages after exosome treatment were co-cultured with A549 or H1299 cells. The invasion of lung adenocarcinoma cells was tested by TranswellTM assay and the mRNA levels of MMP9, MMP2 in lung adenocarcinoma cells were detected by RT-qPCR. Results CD9 and CD63 were highly expressed in exosomes. The THP-1 cells after PMA induction produced a high level of CD68. After the macrophages were treated with exosomes, the expression of iNOS decreased and the expression of CD163, TNF-α, IL-6, IL-8 and IL-10 significantly increased in the macrophages. The co-culture of macrophages with A549 and H1299 after exosome treatment enhanced significantly the invasion ability of lung adenocarcinoma cells and increased the levels of MMP2 and MMP9. Conclusion The exosomes derived from lung adenocarcinoma cells can activate macrophages to exhibit a mixed M1/M2 phenotype, thus promot the invasion of lung cancer cells.


Assuntos
Adenocarcinoma de Pulmão/patologia , Exossomos/metabolismo , Neoplasias Pulmonares/patologia , Macrófagos/citologia , Invasividade Neoplásica , Células A549 , Polaridade Celular , Citocinas/metabolismo , Humanos , Óxido Nítrico Sintase Tipo II/metabolismo , Células THP-1
12.
Phys Rev Lett ; 123(23): 238101, 2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31868441

RESUMO

Ultrasound irradiation makes it possible to generate alternating electric polarization through the electromechanical coupling of materials. It follows that electromagnetic fields are often emitted to the surrounding environment when materials are acoustically stimulated. We investigate the acoustically stimulated electromagnetic (ASEM) response of soft biological tissues. The ASEM signal is detected through a capacitive resonant antenna tuned to the MHz frequency of the irradiated ultrasound waves. The signal is well explained by the stress-induced polarization, which responds linearly to the applied acoustic stress. Induced polarization is clearly observed in the Achilles tendon, aortic wall, and aortic valve samples, whereas it is small in adipose tissue and myocardium samples, indicating that fibrous tissues exhibit electromechanical coupling.


Assuntos
Tendão do Calcâneo/efeitos da radiação , Tecido Adiposo/efeitos da radiação , Aorta/efeitos da radiação , Coração/efeitos da radiação , Ondas Ultrassônicas , Animais , Valva Aórtica/efeitos da radiação , Bovinos , Polaridade Celular/efeitos da radiação , Campos Eletromagnéticos , Modelos Biológicos , Suínos
13.
PLoS Comput Biol ; 15(11): e1007468, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31738746

RESUMO

Macrophages respond to signals in the microenvironment by changing their functional phenotypes, a process known as polarization. Depending on the context, they acquire different patterns of transcriptional activation, cytokine expression and cellular metabolism which collectively constitute a continuous spectrum of phenotypes, of which the two extremes are denoted as classical (M1) and alternative (M2) activation. To quantitatively decode the underlying principles governing macrophage phenotypic polarization and thereby harness its therapeutic potential in human diseases, a systems-level approach is needed given the multitude of signaling pathways and intracellular regulation involved. Here we develop the first mechanism-based, multi-pathway computational model that describes the integrated signal transduction and macrophage programming under M1 (IFN-γ), M2 (IL-4) and cell stress (hypoxia) stimulation. Our model was calibrated extensively against experimental data, and we mechanistically elucidated several signature feedbacks behind the M1-M2 antagonism and investigated the dynamical shaping of macrophage phenotypes within the M1-M2 spectrum. Model sensitivity analysis also revealed key molecular nodes and interactions as targets with potential therapeutic values for the pathophysiology of peripheral arterial disease and cancer. Through simulations that dynamically capture the signal integration and phenotypic marker expression in the differential macrophage polarization responses, our model provides an important computational basis toward a more quantitative and network-centric understanding of the complex physiology and versatile functions of macrophages in human diseases.


Assuntos
Polaridade Celular/fisiologia , Biologia Computacional/métodos , Ativação de Macrófagos/fisiologia , Citocinas/metabolismo , Humanos , Macrófagos/metabolismo , Macrófagos/fisiologia , Fenótipo , Transdução de Sinais/fisiologia
14.
Phys Rev Lett ; 123(18): 188101, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31763902

RESUMO

The cell cortex, a thin film of active material assembled below the cell membrane, plays a key role in cellular symmetry-breaking processes such as cell polarity establishment and cell division. Here, we present a minimal model of the self-organization of the cell cortex that is based on a hydrodynamic theory of curved active surfaces. Active stresses on this surface are regulated by a diffusing molecular species. We show that coupling of the active surface to a passive bulk fluid enables spontaneous polarization and the formation of a contractile ring on the surface via mechanochemical instabilities. We discuss the role of external fields in guiding such pattern formation. Our work reveals that key features of cellular symmetry breaking and cell division can emerge in a minimal model via general dynamic instabilities.


Assuntos
Forma Celular/fisiologia , Estruturas Celulares/citologia , Modelos Biológicos , Fenômenos Biomecânicos , Divisão Celular/fisiologia , Polaridade Celular/fisiologia , Viscosidade
15.
PLoS Comput Biol ; 15(11): e1007454, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31770364

RESUMO

Planar cell polarity (PCP), the long-range in-plane polarization of epithelial tissues, provides directional information that guides a multitude of developmental processes at cellular and tissue levels. While it is manifest that cells utilize both intracellular and intercellular interactions, the coupling between the two modules, essential to the coordination of collective polarization, remains an active area of investigation. We propose a generalized reaction-diffusion model to study the role of intracellular interactions in the emergence of long-range polarization, and show that the nonlocality of cytoplasmic interactions, i.e. coupling of membrane proteins localized on different cell-cell junctions, is of vital importance to the faithful detection of weak directional signals, and becomes increasingly more crucial to the stability of polarization against the deleterious effects of large geometric irregularities. We demonstrate that nonlocal interactions are necessary for geometric information to become accessible to the PCP components. The prediction of the model regarding polarization in elongated tissues, is shown to be in agreement with experimental observations, where the polarity emerges perpendicular to the axis of elongation. Core PCP is adopted as a model pathway, in term of which we interpret the model parameters. To this end, we introduce three distinct classes of mutations, (I) in membrane proteins, (II) in cytoplasmic proteins, and (III) local enhancement of geometric disorder. Comparing the in silico and in vivo phenotypes, we show that our model successfully recapitulates the salient phenotypic features of these mutations. Exploring the parameter space helps us shed light on the role of cytoplasmic proteins in cell-cell communications, and make falsifiable predictions regarding the cooperation of cytoplasmic and membrane proteins in the establishment of long-range polarization.


Assuntos
Padronização Corporal/fisiologia , Polaridade Celular/fisiologia , Biologia Computacional/métodos , Animais , Comunicação Celular , Citoplasma/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Proteínas de Membrana/metabolismo , Modelos Biológicos , Modelos Teóricos , Transdução de Sinais
16.
BMC Complement Altern Med ; 19(1): 314, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31744490

RESUMO

BACKGROUNDS: Inflammation is recognized as the key pathological mechanism of type 2 diabetes. The hypoglyceamic effects of berberine (BBR) are related to the inhibition of the inflammatory response, but the mechanism is not completely clear. METHODS: The inflammatory polarization of Raw264.7 cells and primary peritoneal macrophages were induced by LPS, and then effects and underlying mechanisms of BBR were explored. An inflammatory model was established by LPS treatment at different concentrations for different treatment time. An ELISA assay was used to detect the secretions of TNF-α. RT-PCR was applied to detect M1 inflammatory factors. The F4/80+ ratio and CD11c+ ratio of primary peritoneal macrophages were determined by flow cytometry. The expressions of p-AMPK and TLR4 were detected by Western blot. The cytoplasmic and nuclear distributions of NFκB p65 were observed by confocal microscopy. The binding of TLR4 to MyD88 was tested by CoIP, and the affinity of BBR for TLR4 was assessed by molecular docking. RESULTS: Upon exposure to LPS, the secretion of TNF-α and transcription of inflammatory factors in macrophages increased, cell morphology changed and protrusions appeared gradually, the proportion of F4/80+CD11c+ M1 macrophages increased, and the nuclear distribution of NFκB p65 increased. BBR pretreatment partially inhibited the changes mentioned above. However, the expression of TLR4 and p-AMPK did not change significantly after LPS intervention for 3 h. Meanwhile, CoIP showed that the interaction between TLR4 and MyD88 increased, and BBR inhibited the binding. Molecular docking suggested that BBR might interact with TLR4. CONCLUSIONS: Inflammatory changes were induced in macrophages after LPS stimulation for 3 h, and BBR pretreatment inhibited inflammatory polarization. BBR might interact with TLR4 and disturb TLR4/MyD88/NFκB signalling pathway, and it might be the mechanism by which BBR attenuated inflammation in the early phase.


Assuntos
Berberina/farmacologia , Macrófagos/efeitos dos fármacos , Fator 88 de Diferenciação Mieloide/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Berberina/química , Polaridade Celular/efeitos dos fármacos , Células Cultivadas , Feminino , Humanos , Lipopolissacarídeos/farmacologia , Macrófagos/química , Macrófagos/citologia , Macrófagos/metabolismo , Camundongos , Simulação de Acoplamento Molecular , Fator 88 de Diferenciação Mieloide/química , Fator 88 de Diferenciação Mieloide/genética , Ligação Proteica/efeitos dos fármacos , Células RAW 264.7 , Receptor 4 Toll-Like/química , Receptor 4 Toll-Like/genética , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
17.
Nat Cell Biol ; 21(11): 1309-1320, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31685996

RESUMO

With ageing, intrinsic haematopoietic stem cell (HSC) activity decreases, resulting in impaired tissue homeostasis, reduced engraftment following transplantation and increased susceptibility to diseases. However, whether ageing also affects the HSC niche, and thereby impairs its capacity to support HSC function, is still widely debated. Here, by using in-vivo long-term label-retention assays we demonstrate that aged label-retaining HSCs, which are, in old mice, the most quiescent HSC subpopulation with the highest regenerative capacity and cellular polarity, reside predominantly in perisinusoidal niches. Furthermore, we demonstrate that sinusoidal niches are uniquely preserved in shape, morphology and number on ageing. Finally, we show that myeloablative chemotherapy can selectively disrupt aged sinusoidal niches in the long term, which is linked to the lack of recovery of endothelial Jag2 at sinusoids. Overall, our data characterize the functional alterations of the aged HSC niche and unveil that perisinusoidal niches are uniquely preserved and thereby protect HSCs from ageing.


Assuntos
Envelhecimento/genética , Capilares/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Homeostase/genética , Nicho de Células-Tronco/genética , Envelhecimento/metabolismo , Animais , Medula Óssea/efeitos dos fármacos , Medula Óssea/metabolismo , Capilares/citologia , Capilares/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Polaridade Celular/efeitos dos fármacos , Rastreamento de Células/métodos , Doxiciclina/farmacologia , Fluoruracila/farmacologia , Regulação da Expressão Gênica , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Histonas/genética , Histonas/metabolismo , Homeostase/efeitos dos fármacos , Proteína Jagged-2/genética , Proteína Jagged-2/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Agonistas Mieloablativos/farmacologia , Nicho de Células-Tronco/efeitos dos fármacos
18.
Nat Cell Biol ; 21(11): 1370-1381, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31685997

RESUMO

Cell migration is hypothesized to involve a cycle of behaviours beginning with leading edge extension. However, recent evidence suggests that the leading edge may be dispensable for migration, raising the question of what actually controls cell directionality. Here, we exploit the embryonic migration of Drosophila macrophages to bridge the different temporal scales of the behaviours controlling motility. This approach reveals that edge fluctuations during random motility are not persistent and are weakly correlated with motion. In contrast, flow of the actin network behind the leading edge is highly persistent. Quantification of actin flow structure during migration reveals a stable organization and asymmetry in the cell-wide flowfield that strongly correlates with cell directionality. This organization is regulated by a gradient of actin network compression and destruction, which is controlled by myosin contraction and cofilin-mediated disassembly. It is this stable actin-flow polarity, which integrates rapid fluctuations of the leading edge, that controls inherent cellular persistence.


Assuntos
Actinas/genética , Movimento Celular/genética , Drosophila melanogaster/embriologia , Mecanotransdução Celular , Peixe-Zebra/embriologia , Actinas/metabolismo , Animais , Polaridade Celular , Rastreamento de Células , Cofilina 1/genética , Cofilina 1/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Embrião não Mamífero , Regulação da Expressão Gênica no Desenvolvimento , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Hemócitos/citologia , Hemócitos/metabolismo , Queratinócitos/citologia , Queratinócitos/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Macrófagos/citologia , Macrófagos/metabolismo , Miosinas/genética , Miosinas/metabolismo , Cultura Primária de Células , Peixe-Zebra/genética , Peixe-Zebra/metabolismo
19.
PLoS Biol ; 17(10): e3000466, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31658245

RESUMO

The pre- and postsynaptic membranes comprising the synaptic junction differ in protein composition. The membrane trafficking mechanisms by which neurons control surface polarization of synaptic receptors remain poorly understood. The sorting receptor Sortilin-related CNS expressed 1 (SorCS1) is a critical regulator of trafficking of neuronal receptors, including the presynaptic adhesion molecule neurexin (Nrxn), an essential synaptic organizer. Here, we show that SorCS1 maintains a balance between axonal and dendritic Nrxn surface levels in the same neuron. Newly synthesized Nrxn1α traffics to the dendritic surface, where it is endocytosed. Endosomal SorCS1 interacts with the Rab11 GTPase effector Rab11 family-interacting protein 5 (Rab11FIP5)/Rab11 interacting protein (Rip11) to facilitate the transition of internalized Nrxn1α from early to recycling endosomes and bias Nrxn1α surface polarization towards the axon. In the absence of SorCS1, Nrxn1α accumulates in early endosomes and mispolarizes to the dendritic surface, impairing presynaptic differentiation and function. Thus, SorCS1-mediated sorting in dendritic endosomes controls Nrxn axonal surface polarization required for proper synapse development and function.


Assuntos
Proteínas de Ligação ao Cálcio/genética , Córtex Cerebral/metabolismo , Moléculas de Adesão de Célula Nervosa/genética , Neurônios/metabolismo , Receptores de Superfície Celular/genética , Membranas Sinápticas/metabolismo , Transmissão Sináptica/genética , Animais , Proteínas de Ligação ao Cálcio/metabolismo , Polaridade Celular , Córtex Cerebral/citologia , Embrião de Mamíferos , Endocitose , Endossomos/metabolismo , Regulação da Expressão Gênica , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Moléculas de Adesão de Célula Nervosa/metabolismo , Neurônios/ultraestrutura , Cultura Primária de Células , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Transporte Proteico , Ratos , Ratos Wistar , Receptores de Superfície Celular/metabolismo , Membranas Sinápticas/ultraestrutura , Proteínas rab de Ligação ao GTP/genética , Proteínas rab de Ligação ao GTP/metabolismo
20.
Int J Mol Sci ; 20(19)2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31591367

RESUMO

The extracellular matrix (ECM) is a complex network of extracellular-secreted macromolecules, such as collagen, enzymes and glycoproteins, whose main functions deal with structural scaffolding and biochemical support of cells and tissues. ECM homeostasis is essential for organ development and functioning under physiological conditions, while its sustained modification or dysregulation can result in pathological conditions. During cancer progression, epithelial tumor cells may undergo epithelial-to-mesenchymal transition (EMT), a morphological and functional remodeling, that deeply alters tumor cell features, leading to loss of epithelial markers (i.e., E-cadherin), changes in cell polarity and intercellular junctions and increase of mesenchymal markers (i.e., N-cadherin, fibronectin and vimentin). This process enhances cancer cell detachment from the original tumor mass and invasiveness, which are necessary for metastasis onset, thus allowing cancer cells to enter the bloodstream or lymphatic flow and colonize distant sites. The mechanisms that lead to development of metastases in specific sites are still largely obscure but modifications occurring in target tissue ECM are being intensively studied. Matrix metalloproteases and several adhesion receptors, among which integrins play a key role, are involved in metastasis-linked ECM modifications. In addition, cells involved in the metastatic niche formation, like cancer associated fibroblasts (CAF) and tumor associated macrophages (TAM), have been found to play crucial roles in ECM alterations aimed at promoting cancer cells adhesion and growth. In this review we focus on molecular mechanisms of ECM modifications occurring during cancer progression and metastatic dissemination to distant sites, with special attention to lung, liver and bone. Moreover, the functional role of cells forming the tumor niche will also be reviewed in light of the most recent findings.


Assuntos
Biomarcadores Tumorais/metabolismo , Matriz Extracelular/patologia , Metástase Neoplásica/patologia , Antígenos CD/metabolismo , Caderinas/metabolismo , Fibroblastos Associados a Câncer/metabolismo , Polaridade Celular , Progressão da Doença , Transição Epitelial-Mesenquimal , Matriz Extracelular/metabolismo , Fibronectinas/metabolismo , Humanos , Vimentina/metabolismo
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