-
Molecular Vision Feb 2006Vitronectin is a secreted glycoprotein present in blood plasma and is present in the extracellular matrix of many tissues. It was found in the retinal cDNA library that...
PURPOSE
Vitronectin is a secreted glycoprotein present in blood plasma and is present in the extracellular matrix of many tissues. It was found in the retinal cDNA library that contains genes whose expression is upregulated after optic nerve injury in a previous study. The purpose of this study was to assess the temporal and spatial changes in expression of vitronectin and integrin alphav in the retina following optic nerve injury.
METHODS
Adult Balb/c mice underwent crush of the optic nerve in one eye only. RT-PCR was used to determine the temporal expression of vitronectin mRNA in the retina after injury. In addition, expression at the protein level in the retina and the optic nerve of vitronectin and its major receptor subunit, integrin alphav, was analyzed by immunohistochemistry.
RESULTS
Upregulation of vitronectin mRNA in the retina was detected at one day after injury, peaking at three days, and maintained up to one week. An elevated expression of vitronectin protein was also observed in the inner retina, optic nerve head, and the optic nerve after nerve crush. In the inner retina, the increased expression of vitronectin was found in retinal ganglion cells (RGCs) and its surrounding extracellular matrix. Expression of integrin alphav was also increased in the RGC layer and in the glial cells of the nerve head and the crush site.
CONCLUSIONS
As vitronectin is an extracellular protein that can support cell attachment and promote neurite extension, elevated expression of vitronectin and its receptor may facilitate axonal regeneration following injury. We propose that treatment sustaining secretion of endogenous vitronectin or direct application of exogenous vitronectin may be a method to augment regeneration of the severed optic axons.
Topics: Animals; Extracellular Matrix; Immunohistochemistry; Integrin alphaV; Mice; Mice, Inbred BALB C; Nerve Crush; Neuroglia; Optic Nerve; Optic Nerve Injuries; RNA, Messenger; Retina; Retinal Ganglion Cells; Reverse Transcriptase Polymerase Chain Reaction; Time Factors; Tissue Distribution; Up-Regulation; Vitronectin
PubMed: 16479252
DOI: No ID Found -
BioMed Research International 2018Platelet-rich fibrin (PRF) clots and membranes are autologous blood concentrates widely used in oral surgical procedures; less is known, however, about the liquid...
OBJECTIVE
Platelet-rich fibrin (PRF) clots and membranes are autologous blood concentrates widely used in oral surgical procedures; less is known, however, about the liquid formulations of such products. The aim of this in vitro study is to assess the behavior of different implant surfaces when in contact with two liquid leucocyte- and platelet-rich fibrin (L-PRF) products.
METHODS
Six commercial pure titanium discs, of 9.5 mm diameter and 1.5 mm thickness, were used. Three of these samples had a micro/nano-rough surface; three were machined. Three different protocols were tested. Protocols involved the immersion of the samples in (1) a platelets, lymphocytes, and fibrinogen liquid concentrate (PLyF) for 10 minutes, (2) an exudate obtained from L-PRF clots rich in fibronectin and vitronectin for 5 minutes, and (3) the fibronectin/vitronectin exudate for 2 minutes followed by immersion in the PLyF concentrate for further 8 minutes. After these treatments, the samples were fixed and observed using a scanning electron microscope (SEM).
RESULTS
Under microscopic observation, (1) the samples treated with the PLyF concentrate revealed a dense fibrin network in direct contact with the implant surface and a significant number of formed elements of blood; (2) in the samples treated with the fibronectin/vitronectin exudates, only a small number of white and red blood cells were detectable; and (3) in samples exposed to the combined treatment, there was an apparent increase in the thickness of the fibrin layer. When compared to the machined surface, the micro/nano-rough samples showed an overall increased retention of fibrin, leading to a thicker coating.
CONCLUSIONS
Liquid L-PRF products promote the formation of a dense fibrin clot on micro/nano-rough implant surfaces in vitro. The adjunctive treatment of surfaces with the fibronectin/vitronectin exudate could provide support to contact of the fibrin with the surface, though it is not essential for the clot formation. Further studies are necessary to better elucidate the properties and benefits of liquid L-PRF products.
Topics: Biomimetics; Blood Coagulation; Blood Platelets; Fibrin; Fibronectins; Humans; Leukocytes; Lymphocytes; Platelet-Rich Fibrin; Prostheses and Implants; Vitronectin
PubMed: 29854805
DOI: 10.1155/2018/9031435 -
PLoS Pathogens Jul 2022During hematogenously disseminated candidiasis, blood borne fungi must invade the endothelial cells that line the blood vessels to infect the deep tissues. Although...
During hematogenously disseminated candidiasis, blood borne fungi must invade the endothelial cells that line the blood vessels to infect the deep tissues. Although Candida albicans, which forms hyphae, readily invades endothelial cells, other medically important species of Candida are poorly invasive in standard in vitro assays and have low virulence in immunocompetent mouse models of disseminated infection. Here, we show that Candida glabrata, Candida tropicalis, Candida parapsilosis, and Candida krusei can bind to vitronectin and high molecular weight kininogen present in human serum. Acting as bridging molecules, vitronectin and kininogen bind to αv integrins and the globular C1q receptor (gC1qR), inducing human endothelial cells to endocytose the fungus. This mechanism of endothelial cell invasion is poorly supported by mouse endothelial cells but can be restored when mouse endothelial cells are engineered to express human gC1qR or αv integrin. Overall, these data indicate that bridging molecule-mediated endocytosis is a common pathogenic strategy used by many medically important Candida spp. to invade human vascular endothelial cells.
Topics: Animals; Candida; Candida albicans; Candidiasis; Endothelial Cells; Humans; Mice; Vitronectin
PubMed: 35797411
DOI: 10.1371/journal.ppat.1010681 -
Infection and Immunity Jun 2014Haemophilus influenzae type b (Hib) escapes the host immune system by recruitment of the complement regulator vitronectin, which inhibits the formation of the membrane...
A fine-tuned interaction between trimeric autotransporter haemophilus surface fibrils and vitronectin leads to serum resistance and adherence to respiratory epithelial cells.
Haemophilus influenzae type b (Hib) escapes the host immune system by recruitment of the complement regulator vitronectin, which inhibits the formation of the membrane attack complex (MAC) by inhibiting C5b-C7 complex formation and C9 polymerization. We reported previously that Hib acquires vitronectin at the surface by using Haemophilus surface fibrils (Hsf). Here we studied in detail the interaction between Hsf and vitronectin and its role in the inhibition of MAC formation and the invasion of lung epithelial cells. The vitronectin-binding region of Hsf was defined at the N-terminal region comprising Hsf amino acids 429 to 652. Moreover, the Hsf recognition site on vitronectin consisted of the C-terminal amino acids 352 to 374. H. influenzae was killed more rapidly in vitronectin-depleted serum than in normal human serum (NHS), and increased MAC deposition was observed at the surface of an Hsf-deficient H. influenzae mutant. In parallel, Hsf-expressing Escherichia coli selectively acquired vitronectin from serum, resulting in significant inhibition of the MAC. Moreover, when vitronectin was bound to Hsf, increased bacterial adherence and internalization into epithelial cells were observed. Taking our findings together, we have defined a fine-tuned protein-protein interaction between Hsf and vitronectin that may contribute to increased Hib virulence.
Topics: Adhesins, Bacterial; Analysis of Variance; Binding, Competitive; Blood Bactericidal Activity; Cell Adhesion; Complement Membrane Attack Complex; Dose-Response Relationship, Immunologic; Haemophilus influenzae type b; Heparin; Humans; Serum; Vitronectin
PubMed: 24664511
DOI: 10.1128/IAI.01636-13 -
Medicine Aug 2021Over-expression of vitronectin (VN) is associated with tumorigenesis. The present study aimed to evaluate the prognostic value of VN expression in gastric cancer.The...
Over-expression of vitronectin (VN) is associated with tumorigenesis. The present study aimed to evaluate the prognostic value of VN expression in gastric cancer.The least absolute shrinkage and selection operator analysis was performed to screen the hub gene from The Cancer Genome Atlas gastric cancer patients with complete follow-up data, and 347 patients were finally included. Moreover, 102 patients were enrolled from the Affiliated Fuzhou First Hospital of Fujian Medical University. VN expression in paired gastric cancer and adjacent gastric normal tissues was detected using immunohistochemistry, and the clinicopathological significance of VN expression was evaluated. The prognostic significance of VN expression in gastric cancer patients was evaluated using by Kaplan-Meier method and Cox regression analysis and confirmed using Oncomine.VN was the prognosis relative gene which screened by The Cancer Genome Atlas dataset. Moreover, we identified the VN expression in an external dataset by immunohistochemistry. The result demonstrated that VN expression was remarkedly elevated in gastric cancer tissues (P < .001). High VN expression correlated with higher pathological Tumor-Node-Metastasis stage, and poorer survival outcomes. Cox regression analysis showed that VN expression was independently predictive of overall survival (OS) and disease-free survival (P = .004, P < .001, respectively). A prognostic risk score for OS was built based on VN expression. A meta-analysis from Oncomine datasets revealed that significantly lower VN mRNA levels in gastric cancer correlated with poorer OS.VN expression could be a prognostic marker of gastric cancer.
Topics: Biomarkers, Tumor; Chi-Square Distribution; Humans; Kaplan-Meier Estimate; Predictive Value of Tests; Prognosis; Proportional Hazards Models; Risk Assessment; Stomach Neoplasms; Vitronectin
PubMed: 34397822
DOI: 10.1097/MD.0000000000026766 -
Acta Biomaterialia Sep 2018Extracellular matrix (ECM) proteins are key mediators of cell/material interactions. The surface density and conformation of these proteins adsorbed on the material...
UNLABELLED
Extracellular matrix (ECM) proteins are key mediators of cell/material interactions. The surface density and conformation of these proteins adsorbed on the material surface influence cell adhesion and the cellular response. We have previously shown that subtle variations in surface chemistry lead to drastic changes in the conformation of adsorbed fibronectin (FN). On poly(ethyl acrylate) (PEA), FN unfolds and displays domains for cell adhesion and FN-FN interaction, whereas on poly(methyl acrylate) (PMA) - with only one methyl group less - FN remains globular as it is in solution. The effect of the strength of the protein/material interaction in cell response, and its relation to protein density and conformation, has received limited attention so far. In this work, we used FN-functionalized AFM cantilevers to evaluate, via force spectroscopy, the strength of interaction between fibronectin and the underlying polymer which controls FN conformation (PEA and PMA). We found that the strength of FN/PEA interaction is significantly higher than FN/PMA, which limits the mobility of FN layer on PEA, reduces the ability of cells to mechanically reorganize FN and then leads to enhanced proteolysis and degradation of the surrounding matrix with compromised cell viability. By contrast, both PEA and PMA support cell adhesion when FN density is increased and also in the presence of serum or other serum proteins, including vitronectin (VN) and bovine serum albumin (BSA), which provide a higher degree of mobility to the matrix.
STATEMENT OF SIGNIFICANCE
The identification of parameters influencing cell response is of paramount importance for the design of biomaterials that will act as synthetic scaffolds for cells to anchor, grow and, eventually, become specialised tissues. Cells interact with materials through an intermediate layer of proteins adsorbed on the material surface. It is known that the density and conformation of these proteins determine cell behaviour. Here we show that the strength of protein/material interactions, which has received very limited attention so far, is key to understand the cellular response to biomaterials. Very strong protein/material interactions reduce the ability of cells to mechanically reorganize proteins at the material interface which results in enhanced matrix degradation, leading ultimately to compromised cell viability.
Topics: 3T3 Cells; Acrylic Resins; Adsorption; Animals; Biocompatible Materials; Cell Adhesion; Cell Differentiation; Cell Lineage; Cell Survival; Extracellular Matrix; Fibronectins; Humans; Mice; Microscopy, Atomic Force; Microscopy, Fluorescence; Serum Albumin, Bovine; Surface Properties; Vitronectin
PubMed: 30006313
DOI: 10.1016/j.actbio.2018.07.016 -
Fertility and Sterility Oct 1997Vitronectin previously has been extracted from human spermatozoa and messenger RNA (mRNA) encoding vitronectin localized by reverse transcriptase in situ polymerase...
OBJECTIVE
Vitronectin previously has been extracted from human spermatozoa and messenger RNA (mRNA) encoding vitronectin localized by reverse transcriptase in situ polymerase chain reaction (PCR) to spermatocytes of human testis. In the present experiments, we have established ranges for the content of vitronectin in living human spermatozoa and vitronectin concentration within seminal fluid of human ejaculates.
DESIGN
Seminal fluid was obtained by centrifugation and motile sperm selected by swim-up from men with normal and abnormal ejaculates, according to World Health Organization criteria, for vitronectin determinations.
SETTING
Academic research environment.
MAIN OUTCOME MEASURE(S)
Seminal fluid vitronectin concentrations were measured by ELISA and sperm vitronectin content by polyacrylamide gel electrophoresis and semiquantitative Western blots.
RESULT(S)
Vitronectin seminal fluid concentration was 1.35 +/- 1.0 mg/mL (mean +/- SD) for normospermic samples (n = 26) and 0.78 +/- 0.4 mg/mL for azoospermic specimens (n = 6). Vitronectin sperm content ranged from 1 to 15 ng/10(6) motile cells (n = 20). Both high- and low-molecular-weight material was observed. Sperm content of vitronectin did not vary with sperm morphology.
CONCLUSION(S)
These results suggest that spermatozoa represent a major source of seminal fluid vitronectin, but that a secondary source exists, perhaps through transudation from serum.
Topics: Blotting, Western; Electrophoresis, Polyacrylamide Gel; Enzyme-Linked Immunosorbent Assay; Humans; Male; Osmolar Concentration; Semen; Spermatozoa; Vitronectin
PubMed: 9341615
DOI: 10.1016/s0015-0282(97)00312-9 -
Investigative Ophthalmology & Visual... Dec 2020Vitronectin, a cell adhesion and spreading factor, is suspected to play a role in the pathogenesis of age-related macular degeneration (AMD), as it is a major component...
PURPOSE
Vitronectin, a cell adhesion and spreading factor, is suspected to play a role in the pathogenesis of age-related macular degeneration (AMD), as it is a major component of AMD-specific extracellular deposits (e.g., soft drusen, subretinal drusenoid deposits). The present study addressed the impact of AMD-associated non-synonymous variant rs704 in the vitronectin-encoding gene VTN on vitronectin functionality.
METHODS
Effects of rs704 on vitronectin expression and processing were analyzed by semi-quantitative sequencing of VTN transcripts from retinal pigment epithelium (RPE) cells generated from human induced pluripotent stem cells (hiPSCs) and from human neural retina, as well as by western blot analyses on heterologously expressed vitronectin isoforms. Binding of vitronectin isoforms to retinal and endothelial cells was analyzed by western blot. Immunofluorescence staining followed extracellular matrix (ECM) deposition in cultured RPE cells heterologously expressing the vitronectin isoforms. Adhesion of fluorescently labeled RPE or endothelial cells in dependence of recombinant vitronectin or vitronectin-containing ECM was investigated fluorometrically or microscopically. Tube formation and migration assays addressed effects of vitronectin on angiogenesis-related processes.
RESULTS
Variant rs704 affected expression, secretion, and processing but not oligomerization of vitronectin. Cell binding and influence on RPE-mediated ECM deposition differed between AMD-risk-associated and non-AMD-risk-associated protein isoforms. Finally, vitronectin affected adhesion and endothelial tube formation.
CONCLUSIONS
The AMD-risk-associated vitronectin isoform exhibits increased expression and altered functionality in cellular processes related to the sub-RPE aspects of AMD pathology. Although further research is required to address the subretinal disease aspects, this initial study supports an involvement of vitronectin in AMD pathogenesis.
Topics: Blotting, Western; Cell Encapsulation; Cloning, Molecular; Electrophoresis, Polyacrylamide Gel; Extracellular Matrix; Fluorescent Antibody Technique; Genetic Variation; Human Umbilical Vein Endothelial Cells; Humans; Macular Degeneration; Protein Isoforms; Recombinant Proteins; Retina; Retinal Pigment Epithelium; Vitronectin
PubMed: 33259607
DOI: 10.1167/iovs.61.14.2 -
FEBS Letters Nov 1999Staphylococcal gamma-hemolysin and leukocidin are bi-component cytolysins, consisting of LukF (or Hlg1)/Hlg2 and LukF/LukS, respectively. Here, we purified serum...
Vitronectin and its fragments purified as serum inhibitors of Staphylococcus aureus gamma-hemolysin and leukocidin, and their specific binding to the hlg2 and the LukS components of the toxins.
Staphylococcal gamma-hemolysin and leukocidin are bi-component cytolysins, consisting of LukF (or Hlg1)/Hlg2 and LukF/LukS, respectively. Here, we purified serum inhibitors of gamma-hemolysin and leukocidin from human plasma. Protein sequencing showed that the purified inhibitors of 62, 57, 50 and 38 kDa were the vitronectin fragments with truncation(s) of the C-terminal or both N- and C-terminal regions. The purified vitronectin fragments specifically bound to the Hlg2 component of gamma-hemolysin and the LukS component of leukocidin to form high-molecular-weight complexes with them, leading to inhibition of the toxin-induced lysis of human erythrocytes and human polymorphonuclear leukocytes, respectively. Intact vitronectin also showed inhibitory activity to the toxins. The ability of gamma-hemolysin and leukocidin to bind vitronectin and its fragments is a novel function of the pore-forming cytolysins.
Topics: Amino Acid Sequence; Antitoxins; Bacterial Proteins; Bacterial Toxins; Blotting, Western; Chemical Fractionation; Hemolysin Proteins; Humans; Immunoblotting; Leukocidins; Molecular Sequence Data; Peptide Fragments; Protein Binding; Vitronectin
PubMed: 10556515
DOI: 10.1016/s0014-5793(99)01376-9 -
PloS One May 2011Vitronectin is an abundant plasma glycoprotein identified also as a part of extracellular matrix. Vitronectin is substantially enriched at sites of injured, fibrosing,...
BACKGROUND
Vitronectin is an abundant plasma glycoprotein identified also as a part of extracellular matrix. Vitronectin is substantially enriched at sites of injured, fibrosing, inflamed, and tumor tissues where it is believed to be involved in wound healing and tissue remodeling. Little is known about the mechanism of vitronectin localization into the damaged tissues.
METHODOLOGY/PRINCIPAL FINDINGS
2E12 antibody has been described to bind a subset of late apoptotic cells. Using immunoisolation followed by mass spectrometry, we identified the antigen recognized by 2E12 antibody as vitronectin. Based on flow cytometry, we described that vitronectin binds to the late apoptotic and necrotic cells in cell cultures in vitro as well as in murine thymus and spleen in vivo. Confocal microscopy revealed that vitronectin binds to an intracellular cytoplasmic structure after the membrane rupture.
CONCLUSIONS/SIGNIFICANCE
We propose that vitronectin could serve as a marker of membrane disruption in necrosis and apoptosis for flow cytometry analysis. Moreover, we suggest that vitronectin binding to dead cells may represent one of the mechanisms of vitronectin incorporation into the injured tissues.
Topics: Animals; Apoptosis; Cell Line; Cells, Cultured; Erythrocytes; Flow Cytometry; Humans; Jurkat Cells; Mass Spectrometry; Mice; Microscopy, Confocal; Necrosis; Protein Binding; Spleen; Thymus Gland; Vitronectin
PubMed: 21573223
DOI: 10.1371/journal.pone.0019243