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Virulence Dec 2023is an important bacterial pathogen in poultry. Pathogenic bacteria recruit host complement factors to resist the bactericidal effect of serum complement. Vitronectin...
is an important bacterial pathogen in poultry. Pathogenic bacteria recruit host complement factors to resist the bactericidal effect of serum complement. Vitronectin (Vn) is a complementary regulatory protein that inhibits the formation of the membrane attack complex (MAC). Microbes use outer membrane proteins (OMPs) to hijack Vn for complement evasion. However, the mechanism by which achieves evasion is unclear. This study aimed to characterise OMPs of which interact with duck Vn (dVn) during complement evasion. Far-western assays and comparison of wild-type and mutant strains that were treated with dVn and duck serum demonstrated particularly strong binding of OMP76 to dVn. These data were confirmed with strains expressing and not expressing OMP76. Combining tertiary structure analysis and homology modelling, truncated and knocked-out fragments of OMP76 showed that a cluster of critical amino acids in an extracellular loop of OMP76 mediate the interaction with dVn. Moreover, binding of dVn to inhibited MAC deposition on the bacterial surface thereby enhancing survival in duck serum. Virulence of the mutant strain ΔOMP76 was attenuated significantly relative to the wild-type strain. Furthermore, adhesion and invasion abilities of ΔOMP76 decreased, and histopathological changes showed that ΔOMP76 was less virulent in ducklings. Thus, OMP76 is a key virulence factor of . The identification of OMP76-mediated evasion of complement by recruitment of dVn contributes significantly to the understanding of the molecular mechanism by which escapes host innate immunity and provides a new target for the development of subunit vaccines.
Topics: Animals; Virulence; Ducks; Membrane Proteins; Vitronectin; Bacterial Proteins; Flavobacteriaceae Infections; Immunologic Factors; Complement System Proteins; Poultry Diseases
PubMed: 37326479
DOI: 10.1080/21505594.2023.2223060 -
Molecules (Basel, Switzerland) Nov 2020Multivalent interactions frequently occur in biological systems and typically provide higher binding affinity and selectivity in target recognition than when only... (Review)
Review
Multivalent interactions frequently occur in biological systems and typically provide higher binding affinity and selectivity in target recognition than when only monovalent interactions are operative. Thus, taking inspiration by nature, bivalent or multivalent nucleic acid aptamers recognizing a specific biological target have been extensively studied in the last decades. Indeed, oligonucleotide-based aptamers are suitable building blocks for the development of highly efficient multivalent systems since they can be easily modified and assembled exploiting proper connecting linkers of different nature. Thus, substantial research efforts have been put in the construction of dimeric/multimeric versions of effective aptamers with various degrees of success in target binding affinity or therapeutic activity enhancement. The present review summarizes recent advances in the design and development of dimeric and multimeric DNA-based aptamers, including those forming G-quadruplex (G4) structures, recognizing different key proteins in relevant pathological processes. Most of the designed constructs have shown improved performance in terms of binding affinity or therapeutic activity as anti-inflammatory, antiviral, anticoagulant, and anticancer agents and their number is certainly bound to grow in the next future.
Topics: Anti-Inflammatory Agents; Anticoagulants; Antineoplastic Agents; Antiviral Agents; Aptamers, Nucleotide; CD3 Complex; Cell Adhesion Molecules; DNA; Dimerization; G-Quadruplexes; Humans; Immunoglobulin M; Phosphoproteins; Protein Structure, Secondary; Proto-Oncogene Proteins c-met; Pyrrolidines; RNA-Binding Proteins; Receptor Protein-Tyrosine Kinases; Receptors, Antigen, T-Cell; Vascular Endothelial Growth Factor A; Vitronectin; Nucleolin
PubMed: 33182593
DOI: 10.3390/molecules25225227 -
Neuroscience Letters Feb 2021Vitronectin, an extracellular matrix protein, controls the differentiation of cerebellar granule cell precursors (CGCPs) via αvβ5 integrin, particularly in the initial...
Vitronectin, an extracellular matrix protein, controls the differentiation of cerebellar granule cell precursors (CGCPs) via αvβ5 integrin, particularly in the initial stage of differentiation to granule cells. In this study, we determined whether vitronectin regulates axon specification in this initial differentiation stage of CGCPs. First, we analyzed whether vitronectin deficiency, β5 integrin knockdown (KD), and β5 integrin overexpression affect axon specification of primary cultured CGCPs. Vitronectin deficiency and β5 integrin KD inhibited axon formation, while vitronectin administrated- and β5 integrin overexpressed-neurons formed multiple axons. Moreover, KD of β5 integrin suppressed vitronectin-induced multiple axon formation. These findings indicate that vitronectin contributes to regulating axon specification via αvβ5 integrin in CGCPs. Next, we determined the signaling pathway involved in regulating vitronectin-induced axon specification. Wortmannin, an inhibitor of phosphatidylinositol 3-kinase (PI3K), inhibited vitronectin-induced multiple axon specification, and lithium chloride, an inhibitor of glyocogen synthase kinase 3 beta (GSK3β), attenuated the inhibitory effect of vitronectin-KO and β5 integrin KD on the specification of CGCPs. In addition, vitronectin induced the phosphorylation of protein kinase B (Akt) and GSK3β in neuroblastoma Neuro2a cells. Taken together, our results indicate that vitronectin plays an important factor in axon formation process in CGCPs via a β5 integrin/PI3K/GSK3β pathway.
Topics: Animals; Axons; Cell Differentiation; Cells, Cultured; Cerebellum; Female; Humans; Mice; Mice, Inbred C57BL; Neural Stem Cells; Pregnancy; Receptors, Vitronectin; Vitronectin
PubMed: 33444672
DOI: 10.1016/j.neulet.2021.135648 -
Academic Forensic Pathology Sep 2019Determination of time passed since burn injury in the living is critical in forensic science. Autophagy biomarkers and vitronectin can play an important role in...
BACKGROUND
Determination of time passed since burn injury in the living is critical in forensic science. Autophagy biomarkers and vitronectin can play an important role in determination of the age of burn injuries through their levels in the tissue.
OBJECTIVE
The aim of this study was to investigate the role of autophagy biomarkers in dating burn injury and to correlate them with the histopathological effects of deep second-degree thermal burn.
METHOD
Fifty-four male rats were used in this study after infliction of second-degree thermal burns to their skin. Samples were taken from them after 30 minutes and one, four, 24, 48, and 72 hours following burn to be examined histologically and also for autophagy biomarkers and vitronectin.
RESULTS
Significant reduction in the autophagy biomarkers (p < 0.001) over the first 24 hours then began to increase but still not reach the normal level up to 72 hours after burn. Vitronectin level increased after burn infliction 1.5-fold after first hour, then up to four-fold after four hours and after that began to decline but still did not reach the normal level up to 72 hours.
CONCLUSION
Autophagy biomarkers can be used as a forensic tool in determination of the time passed since burn infliction in living.
PubMed: 32110251
DOI: 10.1177/1925362119891705 -
The Journal of Pathology Mar 2021Medulloblastoma (MB) is the most common malignant brain tumour in children and is subdivided into four subgroups: WNT, SHH, Group 3, and Group 4. These molecular...
Medulloblastoma (MB) is the most common malignant brain tumour in children and is subdivided into four subgroups: WNT, SHH, Group 3, and Group 4. These molecular subgroups differ in their metastasis patterns and related prognosis rates. Conventional 2D cell culture methods fail to recapitulate these clinical differences. Realistic 3D models of the cerebellum are therefore necessary to investigate subgroup-specific functional differences and their role in metastasis and chemoresistance. A major component of the brain extracellular matrix (ECM) is the glycosaminoglycan hyaluronan. MB cell lines encapsulated in hyaluronan hydrogels grew as tumour nodules, with Group 3 and Group 4 cell lines displaying clinically characteristic laminar metastatic patterns and levels of chemoresistance. The glycoproteins, laminin and vitronectin, were identified as subgroup-specific, tumour-secreted ECM factors. Gels of higher complexity, formed by incorporation of laminin or vitronectin, revealed subgroup-specific adhesion and growth patterns closely mimicking clinical phenotypes. ECM subtypes, defined by relative levels of laminin and vitronectin expression in patient tissue microarrays and gene expression data sets, were able to identify novel high-risk MB patient subgroups and predict overall survival. Our hyaluronan model system has therefore allowed us to functionally characterize the interaction between different MB subtypes and their environment. It highlights the prognostic and pathological role of specific ECM factors and enables preclinical development of subgroup-specific therapies. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.
Topics: Cell Line, Tumor; Cerebellar Neoplasms; Extracellular Matrix; Humans; Hydrogels; Medulloblastoma; Models, Anatomic
PubMed: 33206391
DOI: 10.1002/path.5591 -
Scientific Reports Jun 2021Vitronectin (VN) is a glycoprotein found in extracellular matrix and blood. Collagen, a major extracellular matrix component in mammals, is degraded by cathepsin K...
Vitronectin (VN) is a glycoprotein found in extracellular matrix and blood. Collagen, a major extracellular matrix component in mammals, is degraded by cathepsin K (CatK), which is essential for bone resorption under acidic conditions. The relationship between VN and cathepsins has been unclear. We discovered that VN promoted collagen fibril formation and inhibited CatK activity, and observed its activation in vitro. VN accelerated collagen fibril formation at neutral pH. Collagen fibers formed with VN were in close contact with each other and appeared as scattered flat masses in scanning electron microscopy images. VN formed collagen fibers with high acid solubility and significantly inhibited CatK; the IC was 8.1-16.6 nM and competitive, almost the same as those of human and porcine VNs. VN inhibited the autoprocessing of inactive pro-CatK from active CatK. DeN-glycosylation of VN attenuated the inhibitory effects of CatK and its autoprocessing by VN, but had little effect on acid solubilization of collagen and VN degradation via CatK. CatK inhibition is an attractive treatment approach for osteoporosis and osteoarthritis. These findings suggest that glycosylated VN is a potential biological candidate for CatK inhibition and may help to understand the molecular mechanisms of tissue re-modeling.
Topics: Animals; Cathepsin K; Collagen; Glycosylation; Humans; Swine; Vitronectin
PubMed: 34103584
DOI: 10.1038/s41598-021-91353-6 -
Biomolecules Jan 2023Polyetheretherketone (PEEK) is a thermoplastic polymer that has been recently employed for bone tissue engineering as a result of its biocompatibility and mechanical...
Polyetheretherketone (PEEK) is a thermoplastic polymer that has been recently employed for bone tissue engineering as a result of its biocompatibility and mechanical properties being comparable to human bone. PEEK, however, is a bio-inert material and, when implanted, does not interact with the host tissues, resulting in poor integration. In this work, the surfaces of 3D-printed PEEK disks were functionalized with: (i) an adhesive peptide reproducing [351-359] h-Vitronectin sequence (HVP) and (ii) HVP retro-inverted dimer (D2HVP), that combines the bioactivity of the native sequence (HVP) with the stability toward proteolytic degradation. Both sequences were designed to be anchored to the polymer surface through specific covalent bonds via oxime chemistry. All functionalized PEEK samples were characterized by Water Contact Angle (WCA) measurements, Atomic Force Microscopy (AFM), and X-ray Photoelectron Spectroscopy (XPS) to confirm the peptide enrichment. The biological results showed that both peptides were able to increase cell proliferation at 3 and 21 days. D2HVP functionalized PEEK resulted in an enhanced proliferation across all time points investigated with higher calcium deposition and more elongated cell morphology.
Topics: Humans; Vitronectin; Polymers; Polyethylene Glycols; Ketones; Peptides; Surface Properties
PubMed: 36830615
DOI: 10.3390/biom13020246 -
Scientific Reports Mar 2021Borrelia miyamotoi, a member of the tick-borne relapsing fever spirochetes, shows a serum-resistant phenotype in vitro. This ability of B. miyamotoi may contribute to...
Borrelia miyamotoi, a member of the tick-borne relapsing fever spirochetes, shows a serum-resistant phenotype in vitro. This ability of B. miyamotoi may contribute to bacterial evasion of the host innate immune system. To investigate the molecular mechanism of serum-resistance, we constructed a membrane protein-encoding gene library of B. miyamotoi using Borrelia garinii strain HT59G, which shows a transformable and serum-susceptible phenotype. By screening the library, we found that bom1093 and bom1515 of B. miyamotoi provided a serum-resistant phenotype to the recipient B. garinii. These B. miyamotoi genes are predicted to encode P35-like antigen genes and are conserved among relapsing fever borreliae. Functional analysis revealed that BOM1093 bound to serum vitronectin and that the C-terminal region of BOM1093 was involved in the vitronectin-binding property. Importantly, the B. garinii transformant was not serum-resistant when the C terminus-truncated BOM1093 was expressed. We also observed that the depletion of vitronectin from human serum enhances the bactericidal activity of BOM1093 expressing B. garinii, and the survival rate of BOM1093 expressing B. garinii in vitronectin-depleted serum is enhanced by the addition of purified vitronectin. Our data suggests that B. miyamotoi utilize BOM1093-mediated binding to vitronectin as a mechanism of serum resistance.
Topics: Bacterial Proteins; Borrelia; Humans; Immunity, Innate; Relapsing Fever; Serum; Vitronectin
PubMed: 33750855
DOI: 10.1038/s41598-021-85069-w -
ACS Applied Materials & Interfaces Oct 2022The synthesis and study of the tripeptide Arg-Gly-Asp (RGD), the binding site of different extracellular matrix proteins, e.g., fibronectin and vitronectin, has allowed...
The synthesis and study of the tripeptide Arg-Gly-Asp (RGD), the binding site of different extracellular matrix proteins, e.g., fibronectin and vitronectin, has allowed the production of a wide range of cell adhesive surfaces. Although the surface density and spacing of the RGD peptide at the nanoscale have already shown a significant influence on cell adhesion, the impact of its hierarchical nanostructure is still rather unexplored. Accordingly, a versatile colloidal system named quatsomes, based on fluid nanovesicles formed by the self-assembling of cholesterol and surfactant molecules, has been devised as a novel template to achieve hierarchical nanostructures of the RGD peptide. To this end, RGD was anchored on the vesicle's fluid membrane of quatsomes, and the RGD-functionalized nanovesicles were covalently anchored to planar gold surfaces, forming a state of quasi-suspension, through a long poly(ethylene glycol) (PEG) chain with a thiol termination. An underlying self-assembled monolayer (SAM) of a shorter PEG was introduced for vesicle stabilization and to avoid unspecific cell adhesion. In comparison with substrates featuring a homogeneous distribution of RGD peptides, the resulting hierarchical nanoarchitectonic dramatically enhanced cell adhesion, despite lower overall RGD molecules on the surface. The new versatile platform was thoroughly characterized using a multitechnique approach, proving its enhanced performance. These findings open new methods for the hierarchical immobilization of biomolecules on surfaces using quatsomes as a robust and novel tissue engineering strategy.
Topics: Integrins; Cell Adhesion; Fibronectins; Vitronectin; Oligopeptides; Polyethylene Glycols; Surface-Active Agents; Sulfhydryl Compounds; Gold
PubMed: 36251059
DOI: 10.1021/acsami.2c10497 -
Journal of Visualized Experiments : JoVE May 2019Dendritic filopodia are thin and long protrusions based on the actin filament, and they extend and retract as if searching for a target axon. When the dendritic...
Dendritic filopodia are thin and long protrusions based on the actin filament, and they extend and retract as if searching for a target axon. When the dendritic filopodia establish contact with a target axon, they begin maturing into spines, leading to the formation of a synapse. Telencephalin (TLCN) is abundantly localized in dendritic filopodia and is gradually excluded from spines. Overexpression of TLCN in cultured hippocampal neurons induces dendritic filopodia formation. We showed that telencephalin strongly binds to an extracellular matrix molecule, vitronectin. Vitronectin-coated microbeads induced phagocytic cup formation on neuronal dendrites. In the phagocytic cup, TLCN, TLCN-binding proteins such as phosphorylated Ezrin/Radixin/Moesin (phospho-ERM), and F-actin are accumulated, which suggests that components of the phagocytic cup are similar to those of dendritic filopodia. Thus, we developed a method for purifying the phagocytic cup instead of dendritic filopodia. Magnetic polystyrene beads were coated with vitronectin, which is abundantly present in the culture medium of hippocampal neurons and which induces phagocytic cup formation on neuronal dendrites. After 24 h of incubation, the phagocytic cups were mildly solubilized with detergent and collected using a magnet separator. After washing the beads, the binding proteins were eluted and analyzed by silver staining and Western blotting. In the binding fraction, TLCN and actin were abundantly present. In addition, many proteins identified from the fraction were localized to the dendritic filopodia; thus, we named the binding fraction as the dendritic filopodia-rich fraction. This article describes details regarding the purification method for the dendritic filopodia-rich fraction.
Topics: Actins; Animals; Cell Fractionation; Cells, Cultured; Dendrites; Hippocampus; Mice; Pseudopodia; Synapses; Vitronectin
PubMed: 31107457
DOI: 10.3791/59292