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1.
Chin J Dent Res ; 27(2): 121-131, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38953477

ABSTRACT

As the biological mechanisms of orthodontic tooth movement have been explored further, scholars have gradually focused on the remodelling mechanism of the extracellular matrix (ECM) in the periodontal ligament (PDL). The ECM of the PDL consists of various types of collagens and other glycoproteins. The specific process and mechanism of ECM remodelling during orthodontic tooth movement remains unclear. Collagen I and III, which constitute major components of the PDL, are upregulated under orthodontic force. The changes in the contents of ECM proteins also depend on the expression of ECM-related enzymes, which organise new collagen fibre networks to adapt to changes in tooth position. The matrix metalloproteinase family is the main enzyme that participates in collagen hydrolysis and renewal and changes its expression under orthodontic force. Moreover, ECM adhesion molecules, such as integrins, are also regulated by orthodontic force and participate in the dynamic reaction of cell adhesion and separation with the ECM. This article reviews the changes in ECM components, related enzymes and adhesion molecules in the PDL under orthodontic force to lay the foundation for the exploration of the regulatory mechanism of ECM remodelling during orthodontic tooth movement.


Subject(s)
Extracellular Matrix , Periodontal Ligament , Tooth Movement Techniques , Extracellular Matrix/metabolism , Humans , Tooth Movement Techniques/methods , Periodontal Ligament/cytology , Periodontium/metabolism , Matrix Metalloproteinases/metabolism , Integrins/metabolism , Collagen/metabolism
2.
Nat Commun ; 15(1): 6131, 2024 Jul 20.
Article in English | MEDLINE | ID: mdl-39033133

ABSTRACT

One question in lymphocyte homing is how integrins are rapidly activated to enable immediate arrest of fast rolling lymphocytes upon encountering chemokines at target vascular beds given the slow chemokine-induced integrin inside-out activation. Herein we demonstrate that chemokine CCL25-triggered Ca2+ influx induces T cell membrane-proximal external Ca2+ concentration ([Ca2+]ex) drop in 6 s from physiological concentration 1.2 mM to 0.3 mM, a critical extracellular Ca2+ threshold for inducing αLß2 activation, triggering rapid αLß2 activation and T cell arrest before occurrence of αLß2 inside-out activation. Talin knockdown inhibits the slow inside-out activation of αLß2 but not [Ca2+]ex drop-triggered αLß2 quick activation. Blocking Ca2+ influx significantly suppresses T cell rolling-to-arrest transition and homing to skin lesions in a mouse psoriasis model, thus alleviating skin inflammation. [Ca2+]ex decrease-triggered rapid integrin activation bridges the gap between initial chemokine stimulation and slow integrin inside-out activation, ensuring immediate lymphocyte arrest and subsequent diapedesis on the right location.


Subject(s)
Calcium , T-Lymphocytes , Talin , Animals , Calcium/metabolism , Mice , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Talin/metabolism , Humans , Psoriasis/metabolism , Psoriasis/immunology , Mice, Inbred C57BL , Cell Membrane/metabolism , Integrins/metabolism , Calcium Signaling , Skin/metabolism
3.
Cell ; 187(13): 3445-3459.e15, 2024 Jun 20.
Article in English | MEDLINE | ID: mdl-38838668

ABSTRACT

Understanding cellular force transmission dynamics is crucial in mechanobiology. We developed the DNA-based ForceChrono probe to measure force magnitude, duration, and loading rates at the single-molecule level within living cells. The ForceChrono probe circumvents the limitations of in vitro single-molecule force spectroscopy by enabling direct measurements within the dynamic cellular environment. Our findings reveal integrin force loading rates of 0.5-2 pN/s and durations ranging from tens of seconds in nascent adhesions to approximately 100 s in mature focal adhesions. The probe's robust and reversible design allows for continuous monitoring of these dynamic changes as cells undergo morphological transformations. Additionally, by analyzing how mutations, deletions, or pharmacological interventions affect these parameters, we can deduce the functional roles of specific proteins or domains in cellular mechanotransduction. The ForceChrono probe provides detailed insights into the dynamics of mechanical forces, advancing our understanding of cellular mechanics and the molecular mechanisms of mechanotransduction.


Subject(s)
Mechanotransduction, Cellular , Single Molecule Imaging , Animals , Humans , Mice , Biomechanical Phenomena , Cell Adhesion , DNA/chemistry , DNA/metabolism , Focal Adhesions/metabolism , Integrins/metabolism , Microscopy, Atomic Force/methods , Single Molecule Imaging/methods , Cell Line , Cell Survival , Base Pairing , Calibration
4.
Cell Death Dis ; 15(6): 397, 2024 Jun 06.
Article in English | MEDLINE | ID: mdl-38844455

ABSTRACT

Integrin αvß6 holds promise as a therapeutic target for organ fibrosis, yet targeted therapies are hampered by concerns over inflammatory-related side effects. The role of αvß6 in renal inflammation remains unknown, and clarifying this issue is crucial for αvß6-targeted treatment of chronic kidney disease (CKD). Here, we revealed a remarkable positive correlation between overexpressed αvß6 in proximal tubule cells (PTCs) and renal inflammation in CKD patients and mouse models. Notably, knockout of αvß6 not only significantly alleviated renal fibrosis but also reduced inflammatory responses in mice, especially the infiltration of pro-inflammatory macrophages. Furthermore, conditional knockout of αvß6 in PTCs in vivo and co-culture of PTCs with macrophages in vitro showed that depleting αvß6 in PTCs suppressed the migration and pro-inflammatory differentiation of macrophages. Screening of macrophage activators showed that αvß6 in PTCs activates macrophages via secreting IL-34. IL-34 produced by PTCs was significantly diminished by αvß6 silencing, and reintroduction of IL-34 restored macrophage activities, while anti-IL-34 antibody restrained macrophage activities enhanced by αvß6 overexpression. Moreover, RNA-sequencing of PTCs and verification experiments demonstrated that silencing αvß6 in PTCs blocked hypoxia-stimulated IL-34 upregulation and secretion by inhibiting YAP expression, dephosphorylation, and nuclear translocation, which resulted in the activation of Hippo signaling. While application of a YAP agonist effectively recurred IL-34 production by PTCs, enhancing the subsequent macrophage migration and activation. Besides, reduced IL-34 expression and YAP activation were also observed in global or PTCs-specific αvß6-deficient injured kidneys. Collectively, our research elucidates the pro-inflammatory function and YAP/IL-34/macrophage axis-mediated mechanism of αvß6 in renal inflammation, providing a solid rationale for the use of αvß6 inhibition to treat kidney inflammation and fibrosis.


Subject(s)
Integrins , Macrophages , Mice, Knockout , Renal Insufficiency, Chronic , Animals , Macrophages/metabolism , Mice , Humans , Integrins/metabolism , Renal Insufficiency, Chronic/pathology , Renal Insufficiency, Chronic/metabolism , Inflammation/pathology , Inflammation/metabolism , Male , Antigens, Neoplasm/metabolism , Mice, Inbred C57BL , Signal Transduction , Disease Models, Animal , YAP-Signaling Proteins/metabolism , Kidney Tubules, Proximal/metabolism , Kidney Tubules, Proximal/pathology , Fibrosis
5.
Drug Dev Res ; 85(4): e22220, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38845229

ABSTRACT

Crohn's disease (CD) is a chronic and debilitating inflammatory bowel disease that affects millions of individuals worldwide. Despite the availability of various treatment options, a significant number of patients do not achieve remission or experience adverse effects with conventional therapies. Vedolizumab, a novel therapeutic agent, has emerged as a promising approach in the management of CD. Despite improvements in treatment choices, there is still a demand for medicines that are efficient and well-tolerated. Vedolizumab, a monoclonal antibody targeting α4ß7 integrin, has emerged as a promising therapeutic approach for the treatment of CD. The review aims to provide a summary of vedolizumab, current treatment options, impact of vedolizumab on the patient's quality of life, mechanism of action, clinical effectiveness, safety and efficacy of vedolizumab, potential side effects or risks associated with vedolizumab therapy, and potential predictors. Furthermore, we investigate limitations and challenges associated with vedolizumab and possible future developments and medical implications. This review provides a comprehensive examination of the present data supporting vedolizumab as a possible treatment option for CD, highlighting its benefits and outlining prospective directions for future study and clinical practice improvement.


Subject(s)
Antibodies, Monoclonal, Humanized , Crohn Disease , Gastrointestinal Agents , Humans , Crohn Disease/drug therapy , Antibodies, Monoclonal, Humanized/therapeutic use , Antibodies, Monoclonal, Humanized/adverse effects , Gastrointestinal Agents/therapeutic use , Gastrointestinal Agents/adverse effects , Quality of Life , Integrins/antagonists & inhibitors
6.
J Cell Biol ; 223(10)2024 Oct 07.
Article in English | MEDLINE | ID: mdl-38889096

ABSTRACT

Immune cells are highly dynamic and able to migrate through environments with diverse biochemical and mechanical compositions. Their migration has classically been defined as amoeboid under the assumption that it is integrin independent. Here, we show that activated primary Th1 T cells require both confinement and extracellular matrix proteins to migrate efficiently. This migration is mediated through small and dynamic focal adhesions that are composed of the same proteins associated with canonical mesenchymal cell focal adhesions, such as integrins, talin, and vinculin. These focal adhesions, furthermore, localize to sites of contractile traction stresses, enabling T cells to pull themselves through confined spaces. Finally, we show that Th1 T cells preferentially follow tracks of other T cells, suggesting that these adhesions modify the extracellular matrix to provide additional environmental guidance cues. These results demonstrate not only that the boundaries between amoeboid and mesenchymal migration modes are ambiguous, but that integrin-mediated focal adhesions play a key role in T cell motility.


Subject(s)
Cell Movement , Extracellular Matrix , Focal Adhesions , Integrins , Talin , Focal Adhesions/metabolism , Animals , Integrins/metabolism , Talin/metabolism , Mice , Extracellular Matrix/metabolism , Vinculin/metabolism , Mice, Inbred C57BL , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Lymphocyte Activation , Cell Adhesion
7.
MAbs ; 16(1): 2365891, 2024.
Article in English | MEDLINE | ID: mdl-38889315

ABSTRACT

Integrins are cell surface receptors that mediate the interactions of cells with their surroundings and play essential roles in cell adhesion, migration, and homeostasis. Eight of the 24 integrins bind to the tripeptide Arg-Gly-Asp (RGD) motif in their extracellular ligands, comprising the RGD-binding integrin subfamily. Despite similarity in recognizing the RGD motif and some redundancy, these integrins can selectively recognize RGD-containing ligands to fulfill specific functions in cellular processes. Antibodies against individual RGD-binding integrins are desirable for investigating their specific functions, and were selected here from a synthetic yeast-displayed Fab library. We discovered 11 antibodies that exhibit high specificity and affinity toward their target integrins, i.e. αVß3, αVß5, αVß6, αVß8, and α5ß1. Of these, six are function-blocking antibodies and contain a ligand-mimetic R(G/L/T)D motif in their CDR3 sequences. We report antibody-binding specificity, kinetics, and binding affinity for purified integrin ectodomains, as well as intact integrins on the cell surface. We further used these antibodies to reveal binding preferences of the αV subunit for its 5 ß-subunit partners: ß6 = ß8 > ß3 > ß1 = ß5.


Subject(s)
Saccharomyces cerevisiae , Humans , Saccharomyces cerevisiae/genetics , Integrin beta Chains/immunology , Integrin beta Chains/chemistry , Integrin beta Chains/metabolism , Integrin beta Chains/genetics , Integrin alphaV/immunology , Integrin alphaV/metabolism , Integrins/immunology , Integrins/metabolism , Peptide Library , Cell Surface Display Techniques , Protein Binding , Antibody Specificity
8.
Int J Mol Sci ; 25(12)2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38928297

ABSTRACT

Senescence is a physiological and pathological cellular program triggered by various types of cellular stress. Senescent cells exhibit multiple characteristic changes. Among them, the characteristic flattened and enlarged morphology exhibited in senescent cells is observed regardless of the stimuli causing the senescence. Several studies have provided important insights into pro-adhesive properties of cellular senescence, suggesting that cell adhesion to the extracellular matrix (ECM), which is involved in characteristic morphological changes, may play pivotal roles in cellular senescence. Matricellular proteins, a group of structurally unrelated ECM molecules that are secreted into the extracellular environment, have the unique ability to control cell adhesion to the ECM by binding to cell adhesion receptors, including integrins. Recent reports have certified that matricellular proteins are closely involved in cellular senescence. Through this biological function, matricellular proteins are thought to play important roles in the pathogenesis of age-related diseases, including fibrosis, osteoarthritis, intervertebral disc degeneration, atherosclerosis, and cancer. This review outlines recent studies on the role of matricellular proteins in inducing cellular senescence. We highlight the role of integrin-mediated signaling in inducing cellular senescence and provide new therapeutic options for age-related diseases targeting matricellular proteins and integrins.


Subject(s)
Aging , Cellular Senescence , Extracellular Matrix Proteins , Integrins , Humans , Integrins/metabolism , Extracellular Matrix Proteins/metabolism , Animals , Aging/metabolism , Extracellular Matrix/metabolism , Signal Transduction , Neoplasms/metabolism , Neoplasms/pathology , Neoplasms/drug therapy , Osteoarthritis/metabolism , Osteoarthritis/pathology , Fibrosis , Cell Adhesion , Atherosclerosis/metabolism , Atherosclerosis/pathology , Intervertebral Disc Degeneration/metabolism , Intervertebral Disc Degeneration/pathology , Molecular Targeted Therapy
9.
Int J Mol Sci ; 25(11)2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38892308

ABSTRACT

Sarcospan (SSPN) is a 25-kDa transmembrane protein that is broadly expressed at the cell surface of many tissues, including, but not limited to, the myofibers from skeletal and smooth muscles, cardiomyocytes, adipocytes, kidney epithelial cells, and neurons. SSPN is a core component of the dystrophin-glycoprotein complex (DGC) that links the intracellular actin cytoskeleton with the extracellular matrix. It is also associated with integrin α7ß1, the predominant integrin expressed in skeletal muscle. As a tetraspanin-like protein with four transmembrane spanning domains, SSPN functions as a scaffold to facilitate protein-protein interactions at the cell membrane. Duchenne muscular dystrophy, Becker muscular dystrophy, and X-linked dilated cardiomyopathy are caused by the loss of dystrophin at the muscle cell surface and a concomitant loss of the entire DGC, including SSPN. SSPN overexpression ameliorates Duchenne muscular dystrophy in the mdx murine model, which supports SSPN being a viable therapeutic target. Other rescue studies support SSPN as a biomarker for the proper assembly and membrane expression of the DGC. Highly specific and robust antibodies to SSPN are needed for basic research on the molecular mechanisms of SSPN rescue, pre-clinical studies, and biomarker evaluations in human samples. The development of SSPN antibodies is challenged by the presence of its four transmembrane domains and limited antigenic epitopes. To address the significant barrier presented by limited commercially available antibodies, we aimed to generate a panel of robust SSPN-specific antibodies that can serve as a resource for the research community. We created antibodies to three SSPN protein epitopes, including the intracellular N- and C-termini as well as the large extracellular loop (LEL) between transmembrane domains 3 and 4. We developed a panel of rabbit antibodies (poly- and monoclonal) against an N-terminal peptide fragment of SSPN. We used several assays to show that the rabbit antibodies recognize mouse SSPN with a high functional affinity and specificity. We developed mouse monoclonal antibodies against the C-terminal peptide and the large extracellular loop of human SSPN. These antibodies are superior to commercially available antibodies and outperform them in various applications, including immunoblotting, indirect immunofluorescence analysis, immunoprecipitation, and an ELISA. These newly developed antibodies will significantly improve the quality and ease of SSPN detection for basic and translational research.


Subject(s)
Membrane Proteins , Translational Research, Biomedical , Animals , Humans , Mice , Dystrophin/metabolism , Dystrophin/immunology , Dystrophin/genetics , Integrins/metabolism , Integrins/immunology , Membrane Proteins/immunology , Membrane Proteins/metabolism , Muscular Dystrophy, Duchenne/immunology , Muscular Dystrophy, Duchenne/metabolism
10.
Front Immunol ; 15: 1403764, 2024.
Article in English | MEDLINE | ID: mdl-38915411

ABSTRACT

Immune system recognizes invading microbes at both pathogen and antigen levels. Toll-like receptors (TLRs) play a key role in the first-line defense against pathogens. Major functions of TLRs include cytokine and chemokine production. TLRs share common downstream signaling pathways with other receptors. The crosstalk revolving around TLRs is rather significant and complex, underscoring the intricate nature of immune system. The profiles of produced cytokines and chemokines via TLRs can be affected by other receptors. Integrins are critical heterodimeric adhesion molecules expressed on many different cells. There are studies describing synergetic or inhibitory interplay between TLRs and integrins. Thus, we reviewed the crosstalk between TLRs and integrins. Understanding the nature of the crosstalk could allow us to modulate TLR functions via integrins.


Subject(s)
Integrins , Receptor Cross-Talk , Signal Transduction , Toll-Like Receptors , Humans , Toll-Like Receptors/metabolism , Integrins/metabolism , Integrins/immunology , Animals , Cytokines/metabolism , Immunity, Innate
11.
Nat Commun ; 15(1): 4986, 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38862544

ABSTRACT

Focal adhesions form liquid-like assemblies around activated integrin receptors at the plasma membrane. How they achieve their flexible properties is not well understood. Here, we use recombinant focal adhesion proteins to reconstitute the core structural machinery in vitro. We observe liquid-liquid phase separation of the core focal adhesion proteins talin and vinculin for a spectrum of conditions and interaction partners. Intriguingly, we show that binding to PI(4,5)P2-containing membranes triggers phase separation of these proteins on the membrane surface, which in turn induces the enrichment of integrin in the clusters. We suggest a mechanism by which 2-dimensional biomolecular condensates assemble on membranes from soluble proteins in the cytoplasm: lipid-binding triggers protein activation and thus, liquid-liquid phase separation of these membrane-bound proteins. This could explain how early focal adhesions maintain a structured and force-resistant organization into the cytoplasm, while still being highly dynamic and able to quickly assemble and disassemble.


Subject(s)
Cell Membrane , Focal Adhesions , Talin , Vinculin , Talin/metabolism , Talin/chemistry , Focal Adhesions/metabolism , Cell Membrane/metabolism , Vinculin/metabolism , Vinculin/chemistry , Humans , Animals , Phosphatidylinositol 4,5-Diphosphate/metabolism , Phosphatidylinositol 4,5-Diphosphate/chemistry , Integrins/metabolism , Integrins/chemistry , Cytoplasm/metabolism , Protein Binding , Phase Separation
12.
Cell Signal ; 120: 111243, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38830562

ABSTRACT

Studies have shown that the abnormal expression of circular RNA (circRNA) is inextricably linked to hepatocellular carcinoma (HCC). Recently, hsa_circ_0000518 (circ_0000518) was discovered in many cancer progressions. However, its function in HCC is still unclear. Through GEO database analysis combined with gene expression detection of HCC related clinical samples and cell lines, we identified that circ_0000518 was abnormally overexpressed in HCC. Cell and animal model experiments jointly indicated that circ_0000518 can stimulate HCC cell proliferation, migration, invasion and suppress apoptosis. Furthermore, we also found that knocking down the circ_0000518 could inhibit the Warburg effect in HCC cells. Mechanistically, circ_0000518 was found to be primarily localized in the cytoplasm, and sponge hsa-miR-326 (miR-326) promoted integrin alpha 5 (ITGA5) expression. In addition, circ_0000518 could enhance the stability of HuR-mediated ITGA5 mRNA, thereby activating the Warburg effect. In conclusion, this study elucidated that circ_0000518 was a cancer-promoting circRNA, which could enhance ITGA5 expression through competing endogenous RNAs (ceRNA) and RNA Binding Protein (RBP) mechanisms, thus facilitating the development of HCC. It provides a meaningful diagnostic and therapeutic target for HCC.


Subject(s)
Carcinoma, Hepatocellular , Cell Proliferation , Liver Neoplasms , MicroRNAs , RNA, Circular , Carcinoma, Hepatocellular/pathology , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/metabolism , Humans , Liver Neoplasms/pathology , Liver Neoplasms/genetics , Liver Neoplasms/metabolism , RNA, Circular/genetics , RNA, Circular/metabolism , MicroRNAs/metabolism , MicroRNAs/genetics , Animals , Cell Line, Tumor , Gene Expression Regulation, Neoplastic , Warburg Effect, Oncologic , Integrin alpha5/metabolism , Integrin alpha5/genetics , Cell Movement , Mice, Nude , Mice , Apoptosis , Disease Progression , Mice, Inbred BALB C , Male , Integrins
13.
Nat Cell Biol ; 26(6): 903-916, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38702503

ABSTRACT

Dynamic changes in mechanical microenvironments, such as cell crowding, regulate lineage fates as well as cell proliferation. Although regulatory mechanisms for contact inhibition of proliferation have been extensively studied, it remains unclear how cell crowding induces lineage specification. Here we found that a well-known oncogene, ETS variant transcription factor 4 (ETV4), serves as a molecular transducer that links mechanical microenvironments and gene expression. In a growing epithelium of human embryonic stem cells, cell crowding dynamics is translated into ETV4 expression, serving as a pre-pattern for future lineage fates. A switch-like ETV4 inactivation by cell crowding derepresses the potential for neuroectoderm differentiation in human embryonic stem cell epithelia. Mechanistically, cell crowding inactivates the integrin-actomyosin pathway and blocks the endocytosis of fibroblast growth factor receptors (FGFRs). The disrupted FGFR endocytosis induces a marked decrease in ETV4 protein stability through ERK inactivation. Mathematical modelling demonstrates that the dynamics of cell density in a growing human embryonic stem cell epithelium precisely determines the spatiotemporal ETV4 expression pattern and, consequently, the timing and geometry of lineage development. Our findings suggest that cell crowding dynamics in a stem cell epithelium drives spatiotemporal lineage specification using ETV4 as a key mechanical transducer.


Subject(s)
Cell Differentiation , Cell Lineage , Human Embryonic Stem Cells , Proto-Oncogene Proteins c-ets , Transcription Factors , Humans , Proto-Oncogene Proteins c-ets/metabolism , Proto-Oncogene Proteins c-ets/genetics , Transcription Factors/metabolism , Transcription Factors/genetics , Human Embryonic Stem Cells/metabolism , Human Embryonic Stem Cells/cytology , Endocytosis , Cell Proliferation , Integrins/metabolism , Integrins/genetics , Signal Transduction , Mechanotransduction, Cellular
14.
Cells ; 13(9)2024 Apr 27.
Article in English | MEDLINE | ID: mdl-38727292

ABSTRACT

Integrin α4ß7+ T cells perpetuate tissue injury in chronic inflammatory diseases, yet their role in hepatic fibrosis progression remains poorly understood. Here, we report increased accumulation of α4ß7+ T cells in the liver of people with cirrhosis relative to disease controls. Similarly, hepatic fibrosis in the established mouse model of CCl4-induced liver fibrosis was associated with enrichment of intrahepatic α4ß7+ CD4 and CD8 T cells. Monoclonal antibody (mAb)-mediated blockade of α4ß7 or its ligand mucosal addressin cell adhesion molecule (MAdCAM)-1 attenuated hepatic inflammation and prevented fibrosis progression in CCl4-treated mice. Improvement in liver fibrosis was associated with a significant decrease in the infiltration of α4ß7+ CD4 and CD8 T cells, suggesting that α4ß7/MAdCAM-1 axis regulates both CD4 and CD8 T cell recruitment to the fibrotic liver, and α4ß7+ T cells promote hepatic fibrosis progression. Analysis of hepatic α4ß7+ and α4ß7- CD4 T cells revealed that α4ß7+ CD4 T cells were enriched for markers of activation and proliferation, demonstrating an effector phenotype. The findings suggest that α4ß7+ T cells play a critical role in promoting hepatic fibrosis progression, and mAb-mediated blockade of α4ß7 or MAdCAM-1 represents a promising therapeutic strategy for slowing hepatic fibrosis progression in chronic liver diseases.


Subject(s)
Cell Adhesion Molecules , Disease Progression , Integrins , Liver Cirrhosis , Liver , Mucoproteins , Animals , Female , Humans , Male , Mice , Antibodies, Monoclonal/pharmacology , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/immunology , Cell Adhesion Molecules/metabolism , Disease Models, Animal , Immunoglobulins/metabolism , Inflammation/pathology , Integrins/metabolism , Liver/pathology , Liver/metabolism , Liver Cirrhosis/chemically induced , Liver Cirrhosis/immunology , Liver Cirrhosis/pathology , Mice, Inbred C57BL , Mucoproteins/metabolism , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Carbon Tetrachloride/pharmacology , Carbon Tetrachloride/toxicity
15.
Cells ; 13(9)2024 May 02.
Article in English | MEDLINE | ID: mdl-38727316

ABSTRACT

Epithelial-mesenchymal transition (EMT) is a process during which epithelial cells lose epithelial characteristics and gain mesenchymal features. Here, we used several cell models to study migratory activity and redistribution of cell-cell adhesion proteins in cells in different EMT states: EGF-induced EMT of epithelial IAR-20 cells; IAR-6-1 cells with a hybrid epithelial-mesenchymal phenotype; and their more mesenchymal derivatives, IAR-6-1-DNE cells lacking adherens junctions. In migrating cells, the cell-cell adhesion protein α-catenin accumulated at the leading edges along with ArpC2/p34 and α-actinin. Suppression of α-catenin shifted cell morphology from fibroblast-like to discoid and attenuated cell migration. Expression of exogenous α-catenin in MDA-MB-468 cells devoid of α-catenin drastically increased their migratory capabilities. The Y654 phosphorylated form of ß-catenin was detected at integrin adhesion complexes (IACs). Co-immunoprecipitation studies indicated that α-catenin and pY654-ß-catenin were associated with IAC proteins: vinculin, zyxin, and α-actinin. Taken together, these data suggest that in cells undergoing EMT, catenins not participating in assembly of adherens junctions may affect cell migration.


Subject(s)
Actin Cytoskeleton , Cell Movement , Epithelial-Mesenchymal Transition , Animals , Actin Cytoskeleton/metabolism , Actinin/metabolism , Adherens Junctions/metabolism , alpha Catenin/metabolism , beta Catenin/metabolism , Cell Adhesion , Cell Line, Tumor , Epithelial Cells/metabolism , Integrins/metabolism , Phosphorylation , Vinculin/metabolism , Zyxin/metabolism , Rats
16.
Biochem Biophys Res Commun ; 721: 150121, 2024 Aug 20.
Article in English | MEDLINE | ID: mdl-38781659

ABSTRACT

The integrin family is a transmembrane receptor that plays critical roles in the cell-cell and cell-extracellular matrix adhesion, signal transduction such as cell cycle regulation, organization of the intracellular cytoskeleton, and immune responses. Consequently, dysfunction of integrins is associated with a wide range of human diseases, including cancer and immune diseases, which makes integrins therapeutic targets for drug discovery. Here we report the cryo-EM structure of the human α-I domain-containing full-length integrin αEß7, which is expressed in the leukocytes of the immune system and a drug target for inflammatory bowel disease (IBD). The structure reveals the half-bent conformation, an intermediate between the close and the open conformation, while the α-I domain responsible for the ligand binding covers the headpiece domain by a unique spatial arrangement. Our results provide the structural information for the drug design targeting IBD.


Subject(s)
Cryoelectron Microscopy , Models, Molecular , Protein Domains , Humans , Integrins/metabolism , Integrins/chemistry , Integrins/ultrastructure , Protein Conformation
17.
Cell ; 187(12): 2990-3005.e17, 2024 Jun 06.
Article in English | MEDLINE | ID: mdl-38772370

ABSTRACT

Integrins link the extracellular environment to the actin cytoskeleton in cell migration and adhesiveness. Rapid coordination between events outside and inside the cell is essential. Single-molecule fluorescence dynamics show that ligand binding to the bent-closed integrin conformation, which predominates on cell surfaces, is followed within milliseconds by two concerted changes, leg extension and headpiece opening, to give the high-affinity integrin conformation. The extended-closed integrin conformation is not an intermediate but can be directly accessed from the extended-open conformation and provides a pathway for ligand dissociation. In contrast to ligand, talin, which links the integrin ß-subunit cytoplasmic domain to the actin cytoskeleton, modestly stabilizes but does not induce extension or opening. Integrin activation is thus initiated by outside-in signaling and followed by inside-out signaling. Our results further imply that talin binding is insufficient for inside-out integrin activation and that tensile force transmission through the ligand-integrin-talin-actin cytoskeleton complex is required.


Subject(s)
Integrins , Talin , Animals , Humans , Mice , Actin Cytoskeleton/metabolism , Actin Cytoskeleton/chemistry , Cell Adhesion , CHO Cells , Cricetulus , Integrins/metabolism , Integrins/chemistry , Ligands , Protein Binding , Protein Conformation , Signal Transduction , Single Molecule Imaging , Talin/metabolism , Talin/chemistry
18.
Biomed Mater ; 19(4)2024 Jun 18.
Article in English | MEDLINE | ID: mdl-38772389

ABSTRACT

The extracellular matrix plays a crucial role in the growth of human neural stem cells (hNSCs) by forming a stem cell niche, bothin vitroandin vivo. The demand for defined synthetic substrates has been increasing recently in stem cell research, reflecting the requirements for precise functions and safety concerns in potential clinical approaches. In this study, we tested the adhesion and expansion of one of the most representative hNSC lines, the ReNcell VM Human Neural Progenitor Cell Line, in a pure-synthesized short peptide-basedin vitroniche using a previously established integrin-binding peptide array. Spontaneous cell differentiation was then induced using two differentin vitroapproaches to further confirm the multipotent features of cells treated with the peptides. Twelve different integrin-binding peptides were capable of supporting hNSC adhesion and expansion at varied proliferation rates. In the ReNcell medium-based differentiation approach, cells detached in almost all peptide-based groups, except integrinα5ß1 binding peptide. In an altered differentiation process induced by retinoic acid containing neural differentiation medium, cell adhesion was retained in all 12 peptide groups. These peptides also appeared to have varied effects on the differentiation potential of hNSCs towards neurons and astrocytes. Our findings provide abundant options for the development ofin vitroneural stem cell niches and will help develop promising tools for disease modeling and future stem cell therapies for neurological diseases.


Subject(s)
Cell Adhesion , Cell Differentiation , Cell Proliferation , Integrins , Neural Stem Cells , Peptides , Humans , Neural Stem Cells/cytology , Neural Stem Cells/metabolism , Cell Differentiation/drug effects , Cell Adhesion/drug effects , Peptides/chemistry , Peptides/pharmacology , Integrins/metabolism , Cell Proliferation/drug effects , Cell Line , Extracellular Matrix/metabolism , Neurons/metabolism , Neurons/cytology , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Tretinoin/pharmacology , Surface Properties , Astrocytes/metabolism , Astrocytes/cytology
19.
Front Immunol ; 15: 1387516, 2024.
Article in English | MEDLINE | ID: mdl-38784377

ABSTRACT

Background: It has been well documented that Takayasu arteritis (TAK) and ulcerative colitis (UC) coexist in the same patients. HLA-B*52 characterizes the co-occurrence, which is one of the common genetic features between these two diseases, indicating shared underlying pathologic mechanisms. Anti-integrin αvß6 antibody (Ab) is present in sera of UC patients in a highly specific manner. We investigated if there were any associations between anti-integrin αvß6 Ab and TAK, considering the risk HLA alleles. Methods: A total of 227 Japanese TAK patients were recruited in the current study and their serum samples were subjected to measurement of anti-integrin αvß6 Ab by ELISA. The clinical information, including the co-occurrence of UC, was collected. The HLA allele carrier status was determined by Luminex or genotype imputation. Results: The information about the presence of UC was available for 165 patients, among which eight (4.84%) patients had UC. Anti-integrin αvß6 antibody was identified in 7 out of 8 TAK subjects with UC (87.5%) while only 5 out of 157 (3.18%) TAK subjects without UC had the antibody (OR 121, p=7.46×10-8). A total of 99 out of 218 (45.4%) patients were HLA-B*52 carriers. There was no significant association between the presence of anti-integrin αvß6 Ab and HLA-B*52 carrier status in those without UC (OR 2.01, 95% CI 0.33-12.4, p = 0.189). Conclusions: The prevalence of anti-integrin αvß6 Ab was high in TAK patients with UC, but not in the absence of concomitant UC. The effect of HLA-B*52 on anti-integrin αvß6 Ab production would be minimal.


Subject(s)
Antigens, Neoplasm , Colitis, Ulcerative , Integrins , Takayasu Arteritis , Humans , Colitis, Ulcerative/immunology , Colitis, Ulcerative/genetics , Takayasu Arteritis/immunology , Takayasu Arteritis/genetics , Female , Integrins/immunology , Male , Adult , Middle Aged , Antigens, Neoplasm/immunology , Antigens, Neoplasm/genetics , HLA-B52 Antigen/immunology , HLA-B52 Antigen/genetics , Alleles , Young Adult , Japan/epidemiology , Genotype , Autoantibodies/blood , Autoantibodies/immunology
20.
Biomed Pharmacother ; 175: 116718, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38744221

ABSTRACT

Advanced cholangiocarcinoma (CCA) presents a clinical challenge due to limited treatment options, necessitating exploration of innovative therapeutic approaches. Bispecific T cell engager (BTE)-armed T cell therapy shows promise in hematological and solid malignancies, offering potential advantages in safety over continuous BTE infusion. In this context, we developed a novel BTE, targeting CD3 on T cells and integrin αvß6, an antigen elevated in various epithelial malignancies, on cancer cells. The novel BTE was generated by fusing an integrin αvß6-binding peptide (A20) to an anti-CD3 (OKT3) single-chain variable fragment (scFv) through a G4S peptide linker (A20/αCD3 BTE). T cells were then armed with A20/αCD3 BTE (A20/αCD3-armed T cells) and assessed for antitumor activity. Our results highlight the specific binding of A20/αCD3 BTE to CD3 on T cells and integrin αvß6 on target cells, effectively redirecting T cells towards these targets. After co-culture, A20/αCD3-armed T cells exhibited significantly heightened cytotoxicity against integrin αvß6-expressing target cells compared to unarmed T cells in both KKU-213A cells and A375.ß6 cells. Moreover, in a five-day co-culture, A20/αCD3-armed T cells demonstrated superior cytotoxicity against KKU-213A spheroids compared to unarmed T cells. Importantly, A20/αCD3-armed T cells exhibited an increased proportion of the effector memory T cell (Tem) subset, upregulation of T cell activation markers, enhanced T cell proliferation, and increased cytolytic molecule/cytokine production, when compared to unarmed T cells in an integrin αvß6-dependent manner. These findings support the potential of A20/αCD3-armed T cells as a novel therapeutic approach for integrin αvß6-expressing cancers.


Subject(s)
Antigens, Neoplasm , Bile Duct Neoplasms , Cholangiocarcinoma , Integrins , T-Lymphocytes , Humans , Cholangiocarcinoma/immunology , Cholangiocarcinoma/therapy , Cholangiocarcinoma/pathology , Antigens, Neoplasm/immunology , T-Lymphocytes/immunology , Integrins/metabolism , Cell Line, Tumor , Bile Duct Neoplasms/immunology , Bile Duct Neoplasms/pathology , Bile Duct Neoplasms/therapy , CD3 Complex/immunology , Single-Chain Antibodies/pharmacology , Coculture Techniques , Antibodies, Bispecific/pharmacology
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