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1.
Open Biol ; 14(4): 230383, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38629124

RESUMO

Non-clustered protocadherins (ncPcdhs) are adhesive molecules with spatio-temporally regulated overlapping expression in the developing nervous system. Although their unique role in neurogenesis has been widely studied, their combinatorial role in brain physiology and pathology is poorly understood. Using probabilistic cell typing by in situ sequencing, we demonstrate combinatorial inter- and intra-familial expression of ncPcdhs in the developing mouse cortex and hippocampus, at single-cell resolution. We discovered the combinatorial expression of Protocadherin-19 (Pcdh19), a protein involved in PCDH19-clustering epilepsy, with Pcdh1, Pcdh9 or Cadherin 13 (Cdh13) in excitatory neurons. Using aggregation assays, we demonstrate a code-specific adhesion function of PCDH19; mosaic PCDH19 absence in PCDH19+9 and PCDH19 + CDH13, but not in PCDH19+1 codes, alters cell-cell interaction. Interestingly, we found that PCDH19 as a dominant protein in two heterophilic adhesion codes could promote trans-interaction between them. In addition, we discovered increased CDH13-mediated cell adhesion in the presence of PCDH19, suggesting a potential role of PCDH19 as an adhesion mediator of CDH13. Finally, we demonstrated novel cis-interactions between PCDH19 and PCDH1, PCDH9 and CDH13. These observations suggest that there is a unique combinatorial code with a cell- and region-specific characteristic where a single molecule defines the heterophilic cell-cell adhesion properties of each code.


Assuntos
Epilepsia , Protocaderinas , Camundongos , Animais , Adesão Celular , Encéfalo , Epilepsia/metabolismo , Neurônios/metabolismo
2.
Proc Natl Acad Sci U S A ; 121(15): e2321759121, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38579009

RESUMO

Adjacent plant cells are connected by specialized cell wall regions, called middle lamellae, which influence critical agricultural characteristics, including fruit ripening and organ abscission. Middle lamellae are enriched in pectin polysaccharides, specifically homogalacturonan (HG). Here, we identify a plant-specific Arabidopsis DUF1068 protein, called NKS1/ELMO4, that is required for middle lamellae integrity and cell adhesion. NKS1 localizes to the Golgi apparatus and loss of NKS1 results in changes to Golgi structure and function. The nks1 mutants also display HG deficient phenotypes, including reduced seedling growth, changes to cell wall composition, and tissue integrity defects. These phenotypes are comparable to qua1 and qua2 mutants, which are defective in HG biosynthesis. Notably, genetic interactions indicate that NKS1 and the QUAs work in a common pathway. Protein interaction analyses and modeling corroborate that they work together in a stable protein complex with other pectin-related proteins. We propose that NKS1 is an integral part of a large pectin synthesis protein complex and that proper function of this complex is important to support Golgi structure and function.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Adesão Celular/genética , Pectinas/metabolismo , Complexo de Golgi/genética , Complexo de Golgi/metabolismo , Parede Celular/metabolismo
3.
PLoS Comput Biol ; 20(4): e1012001, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38557605

RESUMO

Epithelial tissues are the most abundant tissue type in animals, lining body cavities and generating compartment barriers. The function of a monolayered epithelial tissue-whether protective, secretory, absorptive, or filtrative-relies on the side-by-side arrangement of its component cells. The mechanical parameters that determine the shape of epithelial cells in the apical-basal plane are not well-understood. Epithelial tissue architecture in culture is intimately connected to cell density, and cultured layers transition between architectures as they proliferate. This prompted us to ask to what extent epithelial architecture emerges from two mechanical considerations: A) the constraints of densification and B) cell-cell adhesion, a hallmark feature of epithelial cells. To address these questions, we developed a novel polyline cell-based computational model and used it to make theoretical predictions about epithelial architecture upon changes to density and cell-cell adhesion. We tested these predictions using cultured cell experiments. Our results show that the appearance of extended lateral cell-cell borders in culture arises as a consequence of crowding-independent of cell-cell adhesion. However, cadherin-mediated cell-cell adhesion is associated with a novel architectural transition. Our results suggest that this transition represents the initial appearance of a distinctive epithelial architecture. Together our work reveals the distinct mechanical roles of densification and adhesion to epithelial layer formation and provides a novel theoretical framework to understand the less well-studied apical-basal plane of epithelial tissues.


Assuntos
Caderinas , Células Epiteliais , Animais , Epitélio , Adesão Celular , Células Cultivadas
4.
Oncol Res ; 32(4): 753-768, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38560563

RESUMO

Multiple myeloma (MM) is a hematologic malignancy notorious for its high relapse rate and development of drug resistance, in which cell adhesion-mediated drug resistance plays a critical role. This study integrated four RNA sequencing datasets (CoMMpass, GSE136337, GSE9782, and GSE2658) and focused on analyzing 1706 adhesion-related genes. Rigorous univariate Cox regression analysis identified 18 key prognosis-related genes, including KIF14, TROAP, FLNA, MSN, LGALS1, PECAM1, and ALCAM, which demonstrated the strongest associations with poor overall survival (OS) in MM patients. To comprehensively evaluate the impact of cell adhesion on MM prognosis, an adhesion-related risk score (ARRS) model was constructed using Lasso Cox regression analysis. The ARRS model emerged as an independent prognostic factor for predicting OS. Furthermore, our findings revealed that a heightened cell adhesion effect correlated with tumor resistance to DNA-damaging drugs, protein kinase inhibitors, and drugs targeting the PI3K/Akt/mTOR signaling pathway. Nevertheless, we identified promising drug candidates, such as tirofiban, pirenzepine, erlotinib, and bosutinib, which exhibit potential in reversing this resistance. In vitro, experiments employing NCIH929, RPMI8226, and AMO1 cell lines confirmed that MM cell lines with high ARRS exhibited poor sensitivity to the aforementioned candidate drugs. By employing siRNA-mediated knockdown of the key ARRS model gene KIF14, we observed suppressed proliferation of NCIH929 cells, along with decreased adhesion to BMSCs and fibronectin. This study presents compelling evidence establishing cell adhesion as a significant prognostic factor in MM. Additionally, potential molecular mechanisms underlying adhesion-related resistance are proposed, along with viable strategies to overcome such resistance. These findings provide a solid scientific foundation for facilitating clinically stratified treatment of MM.


Assuntos
Mieloma Múltiplo , Humanos , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/genética , Mieloma Múltiplo/patologia , Adesão Celular/genética , Fosfatidilinositol 3-Quinases/metabolismo , Prognóstico , Resistencia a Medicamentos Antineoplásicos/genética , Linhagem Celular Tumoral , Recidiva Local de Neoplasia
5.
J Nanobiotechnology ; 22(1): 158, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589901

RESUMO

In the context of wound healing and tissue regeneration, precise control of cell migration direction is deemed crucial. To address this challenge, polydimethylsiloxane (PDMS) platforms with patterned 10 nm thick TiOx in arrowhead shape were designed and fabricated. Remarkably, without tall sidewall constraints, MC3T3-E1 cells seeded on these platforms were constrained to migrate along the tips of the arrowheads, as the cells were guided by the asymmetrical arrowhead tips which provided large contact areas. To the best of our knowledge, this is the first study demonstrating the use of thin TiOx arrowhead pattern in combination with a cell-repellent PDMS surface to provide guided cell migration unidirectionally without tall sidewall constraints. Additionally, high-resolution fluorescence imaging revealed that the asymmetrical distribution of focal adhesions, triggered by the patterned TiOx arrowheads with arm lengths of 10, 20, and 35 µm, promoted cell adhesion and protrusion along the arrowhead tip direction, resulting in unidirectional cell migration. These findings have important implications for the design of biointerfaces with ultrathin patterns to precisely control cell migration. Furthermore, microelectrodes were integrated with the patterned TiOx arrowheads to enable dynamic monitoring of cell migration using impedance measurement. This microfluidic device integrated with thin layer of guiding pattern and microelectrodes allows simultaneous control of directional cell migration and characterization of the cell movement of individual MC3T3-E1 cells, offering great potential for the development of biosensors for single-cell monitoring.


Assuntos
Dimetilpolisiloxanos , Adesões Focais , Adesão Celular , Movimento Celular
6.
Cell Adh Migr ; 18(1): 1-13, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38566311

RESUMO

Desmosomes are intercellular junctions that regulate mechanical integrity in epithelia and cardiac muscle. Dynamic desmosome remodeling is essential for wound healing and development, yet the mechanisms governing junction assembly remain elusive. While we and others have shown that cadherin ectodomains are highly organized, how this ordered architecture emerges during assembly is unknown. Using fluorescence polarization microscopy, we show that desmoglein 2 (Dsg2) ectodomain order gradually increases during 8 h of assembly, coinciding with increasing adhesive strength. In a scratch wound assay, we observed a similar increase in order in desmosomes assembling at the leading edge of migratory cells. Together, our findings indicate that cadherin organization is a hallmark of desmosome maturity and may play a role in conferring adhesive strength.


Assuntos
Desmogleína 2 , Desmossomos , Caderinas , Junções Intercelulares , Adesão Celular
7.
J Math Biol ; 88(5): 55, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38568280

RESUMO

Cell-cell adhesion plays a vital role in the development and maintenance of multicellular organisms. One of its functions is regulation of cell migration, such as occurs, e.g. during embryogenesis or in cancer. In this work, we develop a versatile multiscale approach to modelling a moving self-adhesive cell population that combines a careful microscopic description of a deterministic adhesion-driven motion component with an efficient mesoscopic representation of a stochastic velocity-jump process. This approach gives rise to mesoscopic models in the form of kinetic transport equations featuring multiple non-localities. Subsequent parabolic and hyperbolic scalings produce general classes of equations with non-local adhesion and myopic diffusion, a special case being the classical macroscopic model proposed in Armstrong et al. (J Theoret Biol 243(1): 98-113, 2006). Our simulations show how the combination of the two motion effects can unfold. Cell-cell adhesion relies on the subcellular cell adhesion molecule binding. Our approach lends itself conveniently to capturing this microscopic effect. On the macroscale, this results in an additional non-linear integral equation of a novel type that is coupled to the cell density equation.


Assuntos
Desenvolvimento Embrionário , Adesão Celular , Movimento Celular , Difusão , Cinética
8.
J Phys Condens Matter ; 36(29)2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38574682

RESUMO

Cell-matrix adhesions connect the cytoskeleton to the extracellular environment and are essential for maintaining the integrity of tissue and whole organisms. Remarkably, cell adhesions can adapt their size and composition to an applied force such that their size and strength increases proportionally to the load. Mathematical models for the clutch-like force transmission at adhesions are frequently based on the assumption that mechanical load is applied tangentially to the adhesion plane. Recently, we suggested a molecular mechanism that can explain adhesion growth under load for planar cell adhesions. The mechanism is based on conformation changes of adhesion molecules that are dynamically exchanged with a reservoir. Tangential loading drives the occupation of some states out of equilibrium, which for thermodynamic reasons, leads to the association of further molecules with the cluster, which we refer to as self-stabilization. Here, we generalize this model to forces that pull at an oblique angle to the plane supporting the cell, and examine if this idealized model also predicts self-stabilization. We also allow for a variable distance between the parallel planes representing cytoskeletal F-actin and transmembrane integrins. Simulation results demonstrate that the binding mechanism and the geometry of the cluster have a strong influence on the response of adhesion clusters to force. For oblique angles smaller than about 40∘, we observe a growth of the adhesion site under force. However this self-stabilization is reduced as the angle between the force and substrate plane increases, with vanishing self-stabilization for normal pulling. Overall, these results highlight the fundamental difference between the assumption of pulling and shearing forces in commonly used models of cell adhesion.


Assuntos
Matriz Extracelular , Adesões Focais , Adesões Focais/metabolismo , Matriz Extracelular/metabolismo , Adesão Celular/fisiologia , Actinas , Integrinas/metabolismo
9.
Curr Protoc ; 4(4): e1022, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38578028

RESUMO

The leukocyte adhesion cascade governs the recruitment of circulating immune cells from the vasculature to distal sites. The initial adhesive interactions between cell surface ligands displaying sialyl-LewisX (sLeX) and endothelial E- and P-selectins serve to slow the cells down enough to interact more closely with the surface, polarize, and exit into the tissues. Therefore, precise microfluidic assays are critical in modeling how well immune cells can interact and "roll" on selectins to slow down enough to complete further steps of the cascade. Here, we present a systematic protocol for selectin mediated rolling on recombinant surfaces and endothelial cell monolayers on polyacrylamide gels of varying stiffness. We also describe step-by-step the protocol for setting up and performing the experiment and how to analyze and present the data collected. This protocol serves to simplify and detail the procedure needed to investigate the initial selectin-mediated interactions of immune cells with the vasculature. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Preparing dishes for cell rolling experiments Basic Protocol 2: Fabrication of polyacrylamide gels for cell rolling experiments Alternate Protocol 1: Protein conjugation with N6 linker Alternate Protocol 2: HUVEC culturing for monolayers Basic Protocol 3: Conducting cell rolling experiments on polyacrylamide gels Basic Protocol 4: ImageJ analysis of cell rolling movies Basic Protocol 5: Quantification of Fc site density on a surface (e.g., for Fc chimeras).


Assuntos
Microfluídica , Selectinas , Adesão Celular , Antígeno Sialil Lewis X , Leucócitos
10.
Eur Phys J E Soft Matter ; 47(4): 22, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38563859

RESUMO

We compare three different setups for measuring cell-cell adhesion. We show that the measured strength depends on the type of setup that is used. For identical cells different assays measure different detachment forces. This can be understood from the fact that cell-cell detachment is a global property of the system. We also analyse the role of external force and line tension on contact angle and cell-cell detachment. Comparison with the experiments suggest that viscous forces play an important role in the process. We dedicate this article to Fyl Pincus who for many of us is an example to be followed not only for outstanding science but also for a marvelous human behavior.


Assuntos
Adesão Celular
11.
Int J Biol Sci ; 20(6): 2297-2309, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38617545

RESUMO

Background: Tyrosine kinase with immunoglobulin and EGF-like domains 1 (TIE1) is known as an orphan receptor prominently expressed in endothelial cells and participates in angiogenesis by regulating TIE2 activity. Our previous study demonstrated elevated TIE1 expression in cervical cancer cells. However, the role of TIE1 in cervical cancer progression, metastasis and treatment remains elusive. Methods: Immunohistochemistry staining for TIE1 and Basigin was performed in 135 human cervical cancer tissues. Overexpressing vectors and siRNAs were used to manipulate gene expression in tumor cells. Colony formation, wound healing, and transwell assays were used to assess cervical cancer cell proliferation and migration in vitro. Subcutaneous xenograft tumor and lung metastasis mouse models were established to examine tumor growth and metastasis. Co-Immunoprecipitation and Mass Spectrometry were applied to explore the proteins binding to TIE1. Immunoprecipitation and immunofluorescence staining were used to verify the interaction between TIE1 and Basigin. Cycloheximide chase assay and MG132 treatment were conducted to analyze protein stability. Results: High TIE1 expression was associated with poor survival in cervical cancer patients. TIE1 overexpression promoted the proliferation, migration and invasion of cervical cancer cells in vitro, as well as tumor growth and metastasis in vivo. In addition, Basigin, a transmembrane glycoprotein, was identified as a TIE1 binding protein, suggesting a pivotal role in matrix metalloproteinase regulation, angiogenesis, cell adhesion, and immune responses. Knockdown of Basigin or treatment with the Basigin inhibitor AC-73 reversed the tumor-promoting effect of TIE1 in vitro and in vivo. Furthermore, we found that TIE1 was able to interact with and stabilize the Basigin protein and stimulate the Basigin-matrix metalloproteinase axis. Conclusion: TIE1 expression in cervical cells exerts a tumor-promoting effect, which is at least in part dependent on its interaction with Basigin. These findings have revealed a TIE2-independent mechanism of TIE1, which may provide a new biomarker for cervical cancer progression, and a potential therapeutic target for the treatment of cervical cancer patients.


Assuntos
Neoplasias Pulmonares , Neoplasias do Colo do Útero , Animais , Feminino , Humanos , Camundongos , Basigina , Adesão Celular , Células Endoteliais , Neoplasias do Colo do Útero/genética
12.
Science ; 383(6689): 1374-1379, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38513010

RESUMO

Cells connect with their environment through surface receptors and use physical tension in receptor-ligand bonds for various cellular processes. Single-molecule techniques have revealed bond strength by measuring "rupture force," but it has long been recognized that rupture force is dependent on loading rate-how quickly force is ramped up. Thus, the physiological loading rate needs to be measured to reveal the mechanical strength of individual bonds in their functional context. We have developed an overstretching tension sensor (OTS) to allow more accurate force measurement in physiological conditions with single-molecule detection sensitivity even in mechanically active regions. We used serially connected OTSs to show that the integrin loading rate ranged from 0.5 to 4 piconewtons per second and was about three times higher in leukocytes than in epithelial cells.


Assuntos
Técnicas Biossensoriais , Adesão Celular , Integrinas , Mecanotransdução Celular , Adesão Celular/fisiologia , Integrinas/química , Integrinas/metabolismo , Imagem Individual de Molécula , Humanos , Linhagem Celular Tumoral , Resistência à Tração , Sondas de Oligonucleotídeos , Hibridização de Ácido Nucleico
13.
14.
Chin J Dent Res ; 27(1): 101-109, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38546525

RESUMO

OBJECTIVE: To explore potential pathogenic processes and possible treatments using unbiased and reliable bioinformatic tools. METHODS: Gene expression profiles of control and hepatocyte growth factor (HGF) samples were downloaded from CNP0000995. Analysis of differentially expressed genes (DEGs) was conducted using R software (version 4.2.1, R Foundation, Vienna, Austria). Functional enrichment analyses were performed using the Gene Ontology (GO), Kyoto Encyclopaedia of Genes and Genomes (KEGG) and Gene Set Enrichment Analysis (GSEA) databases, then the proteinprotein interaction (PPI) network was constructed to screen the top 10 hub genes. Finally, five genes related to cell junctions were selected to build gene-miRNA interactions and predict small-molecule drugs. RESULTS: A total of 342 downregulated genes and 188 upregulated genes were detected. Candidate pathways include the extracellular matrix (ECM) receptor interaction pathway, the TGF-ß signalling pathway and the cell adhesion molecule (CAM) pathway, which were discovered through KEGG and GSEA enrichment studies. GO analyses revealed that these DEGs were significantly enriched in cell adhesion, the adherens junction and focal adhesion. Five hub genes (CDH1, SNAP25, RAC2, APOE and ITGB4) associated with cell adhesion were identified through PPI analysis. Finally, the gene-miRNA regulatory network identified three target miRNAs: hsa-miR-7110-5p, hsa-miR-149-3p and hsa-miR-1207-5p. Based on the gene expression profile, the small-molecule drugs zebularine, ecuronium and prostratin were selected for their demonstrated binding activity when docked with the mentioned molecules. CONCLUSION: This study offered some novel insights into molecular pathways and identified five hub genes associated with cell adhesion. Based on these hub genes, three potential therapeutic miRNAs and small-molecule drugs were predicted, which are expected to provide guidance for the treatment of patients with HGF.


Assuntos
Fibromatose Gengival , MicroRNAs , Humanos , MicroRNAs/genética , Adesão Celular , Adesões Focais
15.
Biofabrication ; 16(3)2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38471164

RESUMO

Cells sense mechanical signals from the surrounding environment and transmit them to the nucleus through mechanotransduction to regulate cellular behavior. Microcontact printing, which utilizes elastomer stamps, is an effective method for simulating the cellular microenvironment and manipulating cell morphology. However, the conventional fabrication process of silicon masters and elastomer stamps requires complex procedures and specialized equipment, which restricts the widespread application of micropatterning in cell biology and hinders the investigation of the role of cell geometry in regulating cell behavior. In this study, we present an innovative method for convenient resin stamp microfabrication based on digital micromirror device planar lithography. Using this method, we generated a series of patterns ranging from millimeter to micrometer scales and validated their effectiveness in controlling adhesion at both collective and individual cell levels. Additionally, we investigated mechanotransduction and cell behavior on elongated micropatterned substrates. We then examined the effects of cell elongation on cytoskeleton organization, nuclear deformation, focal adhesion formation, traction force generation, nuclear mechanics, and the growth of HeLa cells. Our findings reveal a positive correlation between cell length and mechanotransduction. Interestingly, HeLa cells with moderate length exhibit the highest cell division and proliferation rates. These results highlight the regulatory role of cell elongation in mechanotransduction and its significant impact on cancer cell growth. Furthermore, our methodology for controlling cell adhesion holds the potential for addressing fundamental questions in both cell biology and biomedical engineering.


Assuntos
Elastômeros , Mecanotransdução Celular , Humanos , Células HeLa , Adesão Celular/fisiologia , Divisão Celular
16.
J Phys Chem Lett ; 15(14): 3748-3756, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38551401

RESUMO

Cell adhesion peptides (CAPs) often play a critical role in tissue engineering research. However, the discovery of novel CAPs for diverse applications remains a challenging and time-intensive process. This study presents an efficient computational pipeline integrating sequence embeddings, binding predictors, and molecular dynamics simulations to expedite the discovery of new CAPs. A Pro2vec model, trained on vast CAP data sets, was built to identify RGD-similar tripeptide candidates. These candidates were further evaluated for their binding affinity with integrin receptors using the Mutabind2 machine learning model. Additionally, molecular dynamics simulations were applied to model receptor-peptide interactions and calculate their binding free energies, providing a quantitative assessment of the binding strength for further screening. The resulting peptide demonstrated performance comparable to that of RGD in endothelial cell adhesion and spreading experimental assays, validating the efficacy of the integrated computational pipeline.


Assuntos
Oligopeptídeos , Peptídeos , Adesão Celular , Peptídeos/química , Oligopeptídeos/química
17.
Front Immunol ; 15: 1344761, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38487529

RESUMO

Background: The importance of CD11b/CD18 expression in neutrophil effector functions is well known. Beyond KINDLIN3 and TALIN1, which are involved in the induction of the high-affinity binding CD11b/CD18 conformation, the signaling pathways that orchestrate this response remain incompletely understood. Method: We performed an unbiased screening method for protein selection by biotin identification (BioID) and investigated the KINDLIN3 interactome. We used liquid chromatography with tandem mass spectrometry as a powerful analytical tool. Generation of NB4 CD18, KINDLIN3, or SKAP2 knockout neutrophils was achieved using CRISPR-Cas9 technology, and the cells were examined for their effector function using flow cytometry, live cell imaging, microscopy, adhesion, or antibody-dependent cellular cytotoxicity (ADCC). Results: Among the 325 proteins significantly enriched, we identified Src kinase-associated phosphoprotein 2 (SKAP2), a protein involved in actin polymerization and integrin-mediated outside-in signaling. CD18 immunoprecipitation in primary or NB4 neutrophils demonstrated the presence of SKAP2 in the CD11b/CD18 complex at a steady state. Under this condition, adhesion to plastic, ICAM-1, or fibronectin was observed in the absence of SKAP2, which could be abrogated by blocking the actin rearrangements with latrunculin B. Upon stimulation of NB4 SKAP2-deficient neutrophils, adhesion to fibronectin was enhanced whereas CD18 clustering was strongly reduced. This response corresponded with significantly impaired CD11b/CD18-dependent NADPH oxidase activity, phagocytosis, and cytotoxicity against tumor cells. Conclusion: Our results suggest that SKAP2 has a dual role. It may restrict CD11b/CD18-mediated adhesion only under resting conditions, but its major contribution lies in the regulation of dynamic CD11b/CD18-mediated actin rearrangements and clustering as required for cellular effector functions of human neutrophils.


Assuntos
Neutrófilos , Quinases da Família src , Humanos , Neutrófilos/metabolismo , Quinases da Família src/metabolismo , Fibronectinas/metabolismo , Antígenos CD18/metabolismo , Adesão Celular , Actinas/metabolismo , Fosfoproteínas/metabolismo , Antígeno de Macrófago 1/metabolismo
18.
Nano Lett ; 24(14): 4300-4309, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38534038

RESUMO

The imbalance between endogenous and exogenous healing is the fundamental reason for the poor tendon healing. In this study, a Janus patch was developed to promote endogenous healing and inhibit exogenous healing, leading to improved tendon repair. The upper layer of the patch is a poly(dl-lactide-co-glycolide)/polycaprolactone (PLGA/PCL) nanomembrane (PMCP-NM) modified with poly(2-methylacryloxyethyl phosphocholine) (PMPC), which created a lubricated and antifouling surface, preventing cell invasion and mechanical activation. The lower layer is a PLGA/PCL fiber membrane loaded with fibrin (Fb) (Fb-NM), serving as a temporary chemotactic scaffold to regulate the regenerative microenvironment. In vitro, the Janus patch effectively reduced 92.41% cell adhesion and 79.89% motion friction. In vivo, the patch inhibited tendon adhesion through the TGF-ß/Smad signaling pathway and promoted tendon maturation. This Janus patch is expected to provide a practical basis and theoretical guidance for high-quality soft tissue repair.


Assuntos
Tendões , Cicatrização , Tendões/fisiologia , Adesão Celular
19.
Nano Lett ; 24(14): 4279-4290, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38546049

RESUMO

Mechanical extracellular signals elicit chromatin remodeling via the mechanotransduction pathway, thus determining cellular function. However, the reverse pathway is an open question: does chromatin remodeling shape cells, regulating their adhesion strength? With fluidic force microscopy, we can directly measure the adhesion strength of epithelial cells by driving chromatin compaction to decompaction with chromatin remodelers. We observe that chromatin compaction, induced by performing histone acetyltransferase inhibition or ATP depletion, leads to a reduction in nuclear volume, disrupting actin cytoskeleton and focal adhesion assembly, and ultimately decreases in cell adhesion strength and traction force. Conversely, when chromatin decompaction is drived by removing the remodelers, cells recover their original shape, adhesion strength, and traction force. During chromatin decompaction, cells use depolymerized proteins to restore focal adhesion assemblies rather than neo-synthesized cytoskeletal proteins. We conclude that chromatin remodeling shapes cells, regulating adhesion strength through a reverse mechanotransduction pathway from the nucleus to the cell surface involving RhoA activation.


Assuntos
Cromatina , Mecanotransdução Celular , Cromatina/metabolismo , Adesão Celular , Núcleo Celular/metabolismo , Citoesqueleto de Actina
20.
Soft Matter ; 20(11): 2610-2623, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38426537

RESUMO

Adhesive dynamics of cells plays a critical role in determining different biophysical processes orchestrating health and disease in living systems. While the rolling of cells on functionalised substrates having similarity with biophysical pathways appears to be extensively discussed in the literature, the effect of an external stimulus in the form of an electric field on the same remains underemphasized. Here, we bring out the interplay of fluid shear and electric field on the rolling dynamics of adhesive cells in biofunctionalised micro-confinements. Our experimental results portray that an electric field, even restricted to low strengths within the physiologically relevant regimes, can significantly influence the cell adhesion dynamics. We quantify the electric field-mediated adhesive dynamics of the cells in terms of two key parameters, namely, the voltage-altered rolling velocity and the frequency of adhesion. The effect of the directionality of the electric field with respect to the flow direction is also analysed by studying cellular migration with electrical effects acting both along and against the flow. Our experiment, on one hand, demonstrates the importance of collagen functionalisation in the adhesive dynamics of cells through micro channels, while on the other hand, it reveals how the presence of an axial electric field can lead to significant alteration in the kinetic rate of bond breakage, thereby modifying the degree of cell-substrate adhesion and quantifying in terms of the adhesion frequency of the cells. Proceeding further forward, we offer a simple theoretical explanation towards deriving the kinetics of cellular bonding in the presence of an electric field, which corroborates favourably with our experimental outcome. These findings are likely to offer fundamental insights into the possibilities of local control of cellular adhesion via electric field mediated interactions, bearing critical implications in a wide variety of medical conditions ranging from wound healing to cancer metastasis.


Assuntos
Adesivos , Sinais (Psicologia) , Adesão Celular , Fenômenos Biofísicos , Movimento Celular/fisiologia
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