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APL Bioengineering Jun 2022Two meters of DNA in each of our cells must be protected against many types of damage. Mechanoprotection is increasingly understood to be conferred by the nuclear lamina... (Review)
Review
Two meters of DNA in each of our cells must be protected against many types of damage. Mechanoprotection is increasingly understood to be conferred by the nuclear lamina of intermediate filament proteins, but very different patterns of expression and regulation between different cells and tissues remain a challenge to comprehend and translate into applications. We begin with a tutorial style presentation of "tissue blueprints" of lamin expression including single-cell RNA sequencing in major public datasets. Lamin-A, C profiles appear strikingly similar to those for the mechanosensitive factors Vinculin, Yap1, and Piezo1, whereas datasets for lamin-B1 align with and predict regulation by the cell cycle transcription factor, FOXM1, and further predict poor survival across multiple cancers. Various experiments support the distinction between the lamin types and add mechanistic insight into the mechano-regulation of lamin-A, C by both matrix elasticity and externally imposed tissue strain. Both A- and B-type lamins, nonetheless, protect the nucleus from rupture and damage. Ultimately, for mechanically active tissue constructs and organoids as well as cell therapies, lamin levels require particular attention as they help minimize nuclear damage and defects in a cell cycle.
PubMed: 35719698
DOI: 10.1063/5.0080392 -
Clinical Rheumatology Nov 2022Systemic sclerosis (SSc) is an autoimmune disorder that causes vasculopathy and scarring, most commonly in the lungs and skin, but it can also affect other organs....
INTRODUCTION
Systemic sclerosis (SSc) is an autoimmune disorder that causes vasculopathy and scarring, most commonly in the lungs and skin, but it can also affect other organs. Endothelial vinculin plays a critical role in angiogenesis regulation. Therefore, vinculin overexpression in SSc may give rise to anti-vinculin antibodies, which may contribute to the development of SSc vasculopathy. The current research aims to (1) determine whether anti-vinculin autoantibodies play a significant role in the diagnosis of SSc and (2) compare anti-vinculin serum levels between two scleroderma patient populations, namely, pulmonary artery hypertension (PAH)-predominant and interstitial pulmonary fibrosis (IPF)-predominant groups.
METHODS
This research included 140 participants categorized into three groups: group I-patients with PAH-predominant; group II-patients with ILD-predominant; group III-the control group. Anti-vinculin antibodies were detected in serum samples collected from all participants using ELISA. All subjects underwent high-resolution computed tomography (CT), diffusing capacity for carbon monoxide, and pulmonary function tests.
RESULTS
Patients in group I (PAH-predominant group, N = 35) were 41.3 [± 11.4] years old, with 80% being women. Patients in group II (ILD-predominant group, N = 35) were 41.0 [± 11.5] years old. The SSc group showed significantly higher anti-vinculin antibody levels than the control group (P < 0.001). The PAH-predominant group demonstrated significantly higher anti-vinculin antibody levels and anti-vinculin positivity than the ILD-predominant group.
CONCLUSION
Anti-vinculin antibodies in the blood appear to be diagnostic biomarkers for scleroderma. Furthermore, they shed light on some novel perspectives on the pathophysiology of specific lung fibrotic changes. Key Points • This study included two groups of systemic sclerosis patients (PAH-predominant group, ILD-predominant group) as well as a control group to investigate the significance of anti-vinculin antibodies in such cases. • Our results have demonstrated that anti-vinculin antibodies can play a significant role in diagnosing and monitoring systemic sclerosis disease.
Topics: Autoantibodies; Biomarkers; Carbon Monoxide; Egypt; Female; Humans; Lung Diseases, Interstitial; Male; Scleroderma, Systemic; Vascular Diseases
PubMed: 35876914
DOI: 10.1007/s10067-022-06301-0 -
Frontiers in Molecular Biosciences 2019The advent of cell-cell and cell-extracellular adhesion enabled cells to interact in a coherent manner, forming larger structures and giving rise to the development of... (Review)
Review
The advent of cell-cell and cell-extracellular adhesion enabled cells to interact in a coherent manner, forming larger structures and giving rise to the development of tissues, organs and complex multicellular life forms. The development of such organisms required tight regulation of dynamic adhesive structures by signaling pathways that coordinate cell attachment. Integrin-mediated adhesion to the extracellular matrix provides cells with support, survival signals and context-dependent cues that enable cells to run different cellular programs. One mysterious aspect of the process is how hundreds of proteins assemble seemingly spontaneously onto the activated integrin. An emerging concept is that adhesion assembly is regulated by autoinhibition of key proteins, a highly dynamic event that is modulated by a variety of signaling events. By enabling precise control of the activation state of proteins, autoinhibition enables localization of inactive proteins and the formation of pre-complexes. In response to the correct signals, these proteins become active and interact with other proteins, ultimately leading to development of cell-matrix junctions. Autoinhibition of key components of such adhesion complexes-including core components integrin, talin, vinculin, and FAK and important peripheral regulators such as RIAM, Src, and DLC1-leads to a view that the majority of proteins involved in complex assembly might be regulated by intramolecular interactions. Autoinhibition is relieved via multiple different signals including post-translation modification and proteolysis. More recently, mechanical forces have been shown to stabilize and increase the lifetimes of active conformations, identifying autoinhibition as a means of encoding mechanosensitivity. The complexity and scope for nuanced adhesion dynamics facilitated via autoinhibition provides numerous points of regulation. In this review, we discuss what is known about this mode of regulation and how it leads to rapid and tightly controlled assembly and disassembly of cell-matrix adhesion.
PubMed: 31921890
DOI: 10.3389/fmolb.2019.00144 -
Clinical Rheumatology Mar 2021Gastrointestinal (GI) disease is common in systemic sclerosis, and novel biomarkers are needed to identify and monitor these patients. Dr. Suliman and colleagues...
Gastrointestinal (GI) disease is common in systemic sclerosis, and novel biomarkers are needed to identify and monitor these patients. Dr. Suliman and colleagues identify anti-vinculin autoantibodies in a subset of systemic sclerosis patients which associate with GI symptom severity, although more work is needed to determine their clinical utility.
Topics: Autoantibodies; Biomarkers; Humans; Scleroderma, Systemic
PubMed: 33411141
DOI: 10.1007/s10067-020-05533-2 -
Journal of Cell Science Mar 2021Hippo signaling mediates influences of cytoskeletal tension on organ growth. TRIP6 and LIMD1 have each been identified as being required for tension-dependent inhibition...
Hippo signaling mediates influences of cytoskeletal tension on organ growth. TRIP6 and LIMD1 have each been identified as being required for tension-dependent inhibition of the Hippo pathway LATS kinases and their recruitment to adherens junctions, but the relationship between TRIP6 and LIMD1 was unknown. Using siRNA-mediated gene knockdown, we show that TRIP6 is required for LIMD1 localization to adherens junctions, whereas LIMD1 is not required for TRIP6 localization. TRIP6, but not LIMD1, is also required for the recruitment of vinculin and VASP to adherens junctions. Knockdown of TRIP6 or vinculin, but not of LIMD1, also influences the localization of myosin and F-actin. In TRIP6 knockdown cells, actin stress fibers are lost apically but increased basally, and there is a corresponding increase in the recruitment of vinculin and VASP to basal focal adhesions. Our observations identify a role for TRIP6 in organizing F-actin and maintaining tension at adherens junctions that could account for its influence on LIMD1 and LATS. They also suggest that focal adhesions and adherens junctions compete for key proteins needed to maintain attachments to contractile F-actin.
Topics: Actin Cytoskeleton; Actins; Adherens Junctions; Cytoskeleton; Focal Adhesions; Vinculin
PubMed: 33558314
DOI: 10.1242/jcs.247866 -
Scientific Reports Jul 2019Focal adhesions (FAs) are multiprotein structures that link the intracellular cytoskeleton to the extracellular matrix. They mediate cell adhesion and migration, crucial...
Focal adhesions (FAs) are multiprotein structures that link the intracellular cytoskeleton to the extracellular matrix. They mediate cell adhesion and migration, crucial to many (patho-) physiological processes. We examined in two cell types from different species the binding dynamics of functionally related FA protein pairs: paxillin and vinculin versus zyxin and VASP. In photobleaching experiments ~40% of paxillin and vinculin remained stably associated with a FA for over half an hour. Zyxin and VASP predominantly displayed more transient interactions. We show protein binding dynamics are influenced by FA location and orientation. In FAs located close to the edge of the adherent membrane paxillin, zyxin and VASP were more dynamic and had larger bound fractions. Zyxin and VASP were also more dynamic and had larger bound fractions at FAs perpendicular compared to parallel to this edge. Finally, we developed a photoconversion assay to specifically visualise stably bound proteins within subcellular structures and organelles. This revealed that while paxillin and vinculin are distributed evenly throughout FAs, their stably bound fractions form small clusters within the FA-complex. These clusters are more concentrated for paxillin than for vinculin and are mostly found at the proximal half of the FA where actin also enters.
Topics: Animals; Bone Neoplasms; Cell Adhesion Molecules; Cytoskeleton; Dogs; Extracellular Matrix; Focal Adhesions; Humans; Madin Darby Canine Kidney Cells; Microfilament Proteins; Osteosarcoma; Paxillin; Phosphoproteins; Tumor Cells, Cultured; Vinculin; Zyxin
PubMed: 31320676
DOI: 10.1038/s41598-019-46905-2 -
Vascular Biology (Bristol, England) Jan 2023Remodelling of cell-cell junctions is crucial for proper tissue development and barrier function. The cadherin-based adherens junctions anchor via β-catenin and...
Remodelling of cell-cell junctions is crucial for proper tissue development and barrier function. The cadherin-based adherens junctions anchor via β-catenin and α-catenin to the actomyosin cytoskeleton, together forming a junctional mechanotransduction complex. Tension-induced conformational changes in the mechanosensitive α-catenin protein induce junctional vinculin recruitment. In endothelial cells, vinculin protects the remodelling of VE-cadherin junctions. In this study, we have addressed the role of vinculin in endothelial barrier function in the developing vasculature. In vitro experiments, using endothelial cells in which α-catenin was replaced by a vinculin-binding-deficient mutant, showed that junctional recruitment of vinculin promotes endothelial barrier function. To assess the role of vinculin within blood vessels in vivo, we next investigated barrier function in the vasculature of vcl knockout zebrafish. In the absence of vinculin, sprouting angiogenesis and vessel perfusion still occurred. Intriguingly, the absence of vinculin made the blood vessels more permeable for 10 kDa dextran molecules but not for larger tracers. Taken together, our findings demonstrate that vinculin strengthens the endothelial barrier and prevents vascular leakage in developing vessels.
PubMed: 36260739
DOI: 10.1530/VB-22-0012 -
An ensemble of cadherin-catenin-vinculin complex employs vinculin as the major F-actin binding mode.Biophysical Journal Jun 2023The cell-cell adhesion cadherin-catenin complexes recruit vinculin to the adherens junction (AJ) to modulate the mechanical couplings between neighboring cells. However,...
The cell-cell adhesion cadherin-catenin complexes recruit vinculin to the adherens junction (AJ) to modulate the mechanical couplings between neighboring cells. However, it is unclear how vinculin influences the AJ structure and function. Here, we identified two patches of salt bridges that lock vinculin in the head-tail autoinhibited conformation and reconstituted the full-length vinculin activation mimetics bound to the cadherin-catenin complex. The cadherin-catenin-vinculin complex contains multiple disordered linkers and is highly dynamic, which poses a challenge for structural studies. We determined the ensemble conformation of this complex using small-angle x-ray and selective deuteration/contrast variation small-angle neutron scattering. In the complex, both α-catenin and vinculin adopt an ensemble of flexible conformations, but vinculin has fully open conformations with the vinculin head and actin-binding tail domains well separated from each other. F-actin binding experiments show that the cadherin-catenin-vinculin complex binds and bundles F-actin. However, when the vinculin actin-binding domain is removed from the complex, only a minor fraction of the complex binds to F-actin. The results show that the dynamic cadherin-catenin-vinculin complex employs vinculin as the primary F-actin binding mode to strengthen AJ-cytoskeleton interactions.
Topics: Cadherins; Actins; Vinculin; alpha Catenin; Protein Binding; Actin Cytoskeleton; Cell Adhesion
PubMed: 37147801
DOI: 10.1016/j.bpj.2023.04.026 -
Cell Reports Nov 2023Focal adhesions (FAs) are dynamic protein assemblies that connect cytoskeletons to the extracellular matrix and are crucial for cell adhesion and migration. KANKs are...
Focal adhesions (FAs) are dynamic protein assemblies that connect cytoskeletons to the extracellular matrix and are crucial for cell adhesion and migration. KANKs are scaffold proteins that encircle FAs and act as key regulators of FA dynamics, but the molecular mechanism underlying their specified localization and functions remains poorly understood. Here, we determine the KANK1 structures in complex with talin and liprin-β, respectively. These structures, combined with our biochemical and cellular analyses, demonstrate how KANK1 scaffolds the FA core and associated proteins to modulate the FA shape in response to mechanical force. Additionally, we find that KANK1 undergoes liquid-liquid phase separation (LLPS), which is important for its localization at the FA edge and cytoskeleton connections to FAs. Our findings not only indicate the molecular basis of KANKs in bridging the core and periphery of FAs but also provide insights into the LLPS-mediated dynamic regulation of FA morphology.
Topics: Focal Adhesions; Protein Binding; Cell Adhesion; Cytoskeleton; Talin
PubMed: 37874676
DOI: 10.1016/j.celrep.2023.113321 -
The Israel Medical Association Journal... Jul 2014Giant cell arteritis (GCA) is considered to be a T cell-dependent disease. Autoantibodies have not consistently been found in GCA. The exception is antiphospholipid... (Review)
Review
Giant cell arteritis (GCA) is considered to be a T cell-dependent disease. Autoantibodies have not consistently been found in GCA. The exception is antiphospholipid antibodies (APLA), which were found in 30-80% of GCA cases. Recently, efforts have been made to seek autoantibodies in GCA using newer methods of detection: serological identification of antigens by recombinant cDNA expression cloning, and a proteomic approach. In these studies, lamin C (a nuclear envelope antigen) was recognized by antibodies in 32% of GCA sera and none of the controls. Other autoantigenic proteins were also identified: lamin A, vinculin (a cytoskeleton antigen), and annexin 5 (an endothelial protein). In a recent study, 92% of 36 patients with GCA and/or polymyalgia rheumatica (PMR) had autoantibodies to a human ferritin peptide (the heavy chain N-terminal); 89% had antibodies to bacterial ferritin peptide of Staphylococcus epidermidis. The significance of these findings needs to be studied further. GCA may be a part of the newly described ASIA syndrome (autoimmune syndrome induced by adjuvants). A recent study from Italy reported 10 cases of GCA/PMR within 3 months of influenza vaccination. These comprised 50% of all cases of GCA/PMR diagnosed during the 6 year period of the study. Another 11 cases of GCA following influenza vaccinations were reported. GCA pathogenesis involves all branches of the immune system, including antigen-presenting cells, T cells and B cells, and autoantibody formation is not uncommon. GCA etiology remains unknown, but may be associated with exposure to bacterial or viral antigens.
Topics: Autoantibodies; Giant Cell Arteritis; Humans; Risk Factors
PubMed: 25167695
DOI: No ID Found