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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Exposure of porcine vascular smooth muscle cells to platelet-derived growth factor (PDGF; 18-180 ng/ml) but not epidermal growth factor (EGF; 30 ng/ml), somatomedin C (SmC; 30 ng/ml), or insulin (10 microM), results in a rapid, reversible, time- and concentration-dependent disappearance of vinculin staining in adhesion plaques; actin-containing stress fibers also become disrupted following exposure of cells to PDGF. Disappearance of vinculin staining from adhesion plaques is also caused by 12-O-tetradecanoyl-phorbol-13-acetate (TPA; 200-400 nM), though the time course of the disappearance of vinculin staining under these conditions takes longer than in cells exposed to PDGF. The PDGF-induced removal of vinculin from adhesion plaques was inhibited in a concentration-dependent fashion by 8-(N,N-diethylamino) octyl-3,4,5-trimethoxybenzoate (TMB-8; 0.25-4 microM) and leupepetin (2-300 microM), and by n-alpha-tosyl-L-lysine chloromethylketone (TLCK; 100 microM) and trifluoperazine (TFP; 2.5 microM). Addition of PDGF to vascular smooth muscle cells caused a rapid, transient increase in cytosolic free calcium, from a basal resting level of 146 +/- 6.9 nM (SEM, n = 62) to 414 +/- 34 nM (SEM, n = 22) as determined using the calcium-sensitive indicator Fura-2 and Digitized Video Microscopy. This increase in cellular calcium preceded the disappearance of vinculin from adhesion plaques and was partially blocked by pretreatment of cells with TMB-8 but not leupeptin. This rise in cytosolic free calcium was found to occur in approximately 80% of the sample population and displayed both spatial and temporal subcellular heterogeneity. Exposure of cells to TPA (100 nM) did not result in a change in cytosolic free calcium. Both PDGF (20 ng/ml) and TPA (100 nM) caused cytosolic alkalinization which occurred after PDGF-induced disruption of vinculin from adhesion plaques, as determined using the pH-sensitive indicator BCECF and Digitized Video Microscopy. PDGF stimulated DNA synthesis and vinculin disruption in a similar dose-dependent fashion. Both could be inhibited by leupeptin or TMB-8. These results suggest that 1) exposure of vascular smooth muscle cells to PDGF is associated with the disruption of vinculin from adhesion plaques, 2) PDGF-induced vinculin disruption is regulated by an increase in cytosolic calcium (but not cytosolic alkalinization), and involves proteolysis; 3) activation of protein kinase C also causes vinculin removal from adhesion plaques but by a calcium-independent mechanism, and 4) the cellular response to PDGF-stimulated increases in cytosolic free calcium is heterogeneous.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Platelet-derived growth factor-induced alterations in vinculin distribution in porcine vascular smooth muscle cells. 312 Nov 90

Vinculin- and caldesmon-immunoreactive forms and actin isoform patterns were studied in samples of normal and atherosclerotic human aorta. After removal of adventitia and endothelium, the remaining tissue was divided into three layers: media, muscular-elastic (adjacent to media) intima, and subendothelial (juxtaluminal) intima. In media of normal aorta, meta-vinculin accounted for 41.0 +/- 0.9% (mean +/- SEM) of total immunoreactive vinculin (meta-vinculin + vinculin); 150-kDa caldesmon accounted for 78.2 +/- 5.1% of immunoreactive caldesmon (150-kDa + 70-kDa); the fractional contents of alpha-smooth muscle actin, beta-nonmuscle, and gamma-isoactins were 49.0 +/- 0.6%, 30.4 +/- 0.6%, and 20.8 +/- 0.8%, respectively. Muscular-elastic intima was very similar to media by these criteria. In subendothelial intima, the fractional content of meta-vinculin and 150-kDa caldesmon was significantly lower (6.9 +/- 1.5% and 32.7 +/- 7.0%, respectively) than in muscular-elastic intima and media, whereas the isoactin pattern was identical to that in adjacent layers, demonstrating the smooth muscle origin of subendothelial intima cells. In atherosclerotic fibrous plaque, the fractional content of alpha-actin was decreased in subendothelial intima, rather than in media and muscular-elastic intima. Additionally, the proportion of subendothelial intima cells [i.e., the cells that express low amounts of smooth muscle phenotype markers (meta-vinculin, 150-kDa caldesmon, and alpha-actin)] in the total intima cell population increased dramatically in atherosclerotic fibrous plaque. The results suggest that changes in the relative content of meta-vinculin and 150-kDa caldesmon as well as alpha-actin in human aortic intima are associated with atherosclerosis although, in subendothelial intima of normal aorta, a certain smooth muscle cell population exists that expresses reduced amounts of "contractile" phenotype markers, even in the absence of the disease.
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PMID:Modulation of human aorta smooth muscle cell phenotype: a study of muscle-specific variants of vinculin, caldesmon, and actin expression. 314 99

Two-dimensional gel electrophoresis of acidic and basic [35S]methionine-labeled polypeptides derived from primary cultures of human retinal-pigment epithelial cells revealed about 850 proteins. By co-electrophoresis with highly purified, evolutionally conserved proteins, alpha-actinin, calmodulin, cytosol retinal-binding protein, alpha- and beta-tubulin, and vinculin (mass: 130 000 Da) were tentatively identified in the fluorograms. Quantification of greater than 100 of the excised radioactive spots by liquid scintillation counting revealed an estimated overall gel/gel and donor/donor variation of 40% (SEM, 21%), the latter for data on three to four donors 57 to 81 years old. Therefore, for a difference from normal to be significant (p less than or equal to 0.01), it would, on average, have to exceed 88% of the control mean for that protein. Putative glycoproteins were independently radiolabeled, with tritiated sugars as precursors. Glucosamine was incorporated most rapidly and with the highest specific activity. It labeled about 170 polypeptides. Fucose and N-acetylmannosamine, respectively, labeled 74 and 27 polypeptides. The glycoprotein label was maximal in about 16 very acidic proteins with apparent molecular masses between 50 000 and 150 000 Da. Parallel use of both a sugar and an amino acid label facilitates identification of proteins in two-dimensional gels.
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PMID:Two-dimensional electrophoresis of proteins from cultured human retinal-pigment epithelial cells: internal references, cataloging, and glycoproteins. 649 66

The localization of proteases to cell surfaces via receptors may facilitate cell migration, invasion, and matrix degradation. Since vascular smooth muscle cell (SMC) migration may be an important event in atherosclerosis and in intimal thickening after vascular injury, we studied the cell surface expression of a receptor for urokinase-type plasminogen activator (u-PAR) in cultured human vascular SMC. Using immunofluorescence microscopy, we demonstrated several staining patterns of SMC u-PAR: at the periphery of the cell membrane, at the leading edge, and at cell-cell contact sites. When migration experiments were performed using a wound assay, one-third of the SMC at the wound edge demonstrated polarization of cell surface u-PAR toward the leading edge of the cell membrane (32 +/- 2%, +/- SEM, n = 7). A similar pattern was seen with an antibody to caveolin, a transmembrane protein found in caveolae, but not with an antibody to 5'-nucleotidase, another cell surface glycophosphatidylinositol-anchored protein, which was homogeneously expressed on the cell surface. Low-density lipoprotein receptor-related protein, which mediates internalization of u-PAR bound ligands, was distributed in a diffuse punctate pattern, not polarized to the leading edge. Double immunofluorescent studies demonstrated codistribution of SMC u-PAR with vinculin and caveolin in migrating SMC at the leading edge in a wound assay. Polarization of cell surface u-PAR was not observed in either nonwounded or subconfluent cultures, despite random migratory behavior. These studies suggest that in response to wounding, human vascular SMC polarize and concentrate cell surface u-PAR to their leading edge, perhaps facilitating directional migration.
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PMID:Migrating vascular smooth muscle cells polarize cell surface urokinase receptors after injury in vitro. 786 16

By means of cryo-scanning electron microscopy (cryo-SEM) and fluorescent techniques, evidence is provided on how 12-O-tetradecanoylphorbol-13-acetate (TPA) affects Sertoli cell morphology and F-actin and vinculin organization in vitro. In order to visualize the morphological changes, the cells were observed with cryo-SEM. F-actin was localized using rhodamine (TRI)-phalloidin and vinculin using a primary monoclonal antibody and a second TRI-conjugated antibody. The results indicate that after the addition of 10(-7) M TPA, Sertoli cells begin to round up and their cytoplasm is retracted towards a central region. Actin bundle organization is disrupted and vinculin assumes a punctuate distribution throughout the cell. Thus, the reorganization of actin and vinculin and subsequent changes in cell morphology seem to be brought about by TPA affecting not only actin but also the protein vinculin which interacts with actin. A discussion is made concerning the effect of TPA on cytoskeletal reorganization, which is closely related to cell transformation.
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PMID:The effect of 12-O-tetradecanoylphorbol-13-acetate on Sertoli cell morphology and cytoskeletal organization: an in vitro study by means of cryo-SEM and fluorescent techniques. 1214 41

The role of micrometer and submicrometer surface roughness on the interaction of cells with titanium model surfaces of well-defined topography was investigated using human bone-derived cells (MG63 cells). The early phase of interactions was studied using a kinetic morphological analysis of adhesion, spreading and proliferation of the cells. By SEM and double immunofluorescent labeling of vinculin and actin, it was found that the cells responded to nanoscale roughness by a higher cell thickness and a delayed apparition of the focal contacts. A singular behavior was observed on nanoporous oxide surfaces, where the cells were more spread and displayed longer and more numerous filopods. On electrochemically microstructured surfaces with hemispherical cavities, arranged in a hexagonal pattern, the MG63 cells were able to go inside, adhere and proliferate in cavities of 30 or 100 microm in diameter, whereas they did not recognize the 10 microm diameter cavities. Cells adopted a 3D shape when attaching inside the 30 microm diameter cavities. Condensation of actin cytoskeleton correlated with vinculin-positive focal contacts on cavity edges were observed on all microstructured surfaces. Nanotopography on surfaces with 30 microm diameter cavities had little effect on cell morphology compared to flat surfaces with same nanostructure, but cell proliferation exhibited a marked synergistic effect of microscale and nanoscale topography.
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PMID:Time-dependent morphology and adhesion of osteoblastic cells on titanium model surfaces featuring scale-resolved topography. 1496 49

HA with specific internal porosities was loaded with different antibiotics (ATBs) and then tested on its microbiological effectiveness. The HA purity was controlled with X-ray diffraction, IR and Raman spectrometry. Varying the sintering temperature and/or adding graphite and PMMA as porogenous agents lead to obtained micro- and meso-porosities. The biological tests concerned cell viability, proliferation and morphology (SEM), and the cytochemical staining of actin and vinculin. The micro- and meso-porous HA samples had an internal pore size of 1-10 microm and 10-50 microm, respectively. X-ray diffraction and FTIR confirmed the high purity of the HA. The cell viability tests with L132 cells confirmed the excellent cytocompatibility of HA, the graphite powder and the ATB vancomycine. Proliferation rate was assessed with MC3T3-E1 osteoblasts. All HA samples produced a higher proliferation than the controls; the micro-porous HA inducing the highest cell growth. The ATB impregnated HA also stimulated cell proliferation but in lower extend. Cytochemical staining of osteoblasts revealed a well-developed cytoskeleton with strong stress fibres. Labelling of the focal adhesion contacts with anti-vinculin showed a less developed adhesion process in the cells on the different HA substrates. It was possible to realize a highly pure hydroxyapatite with different but controlled porosities by varying the sintering temperature and/or addition of a porogenous agents. This purity and the micro-porosity stimulate significantly cell growth.
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PMID:Biological and physico-chemical assessment of hydroxyapatite (HA) with different porosity. 1790 Sep 78

One strategy in vascular tissue engineering is the design of hybrid vascular substitutes where vascular cells infiltrate biostable porous scaffolds that provides favorable environment for guided cell repopulation and acts as a mechanically supporting layer after the tissue regeneration process. The aim of the present work was to study the interaction of human coronary artery smooth muscle cells (HCASMC) with 3D porous polyurethane scaffolds. We therefore fabricated porous and highly interconnected 3D polyurethane scaffolds that can promote HCASMC attachment, proliferation, and migration. SEM and microCT studies of the fabricated scaffolds showed that the current scaffolds had highly open and interconnected pore structures, with an average porosity of 84%. HCASMC interaction on polyurethane films revealed that cells adhere and express specific marker proteins (vinculin and h-caldesmon). This expression was further enhanced by coating the polyurethane with Matrigel. On uncoated 3D scaffolds, dense spherical aggregates of cells were often encountered with little adhesion of individual cells alongside the struts of the scaffold, independent of the porogens used. In contrast, when cultured on Matrigel-coated scaffolds, cell numbers quickly increased after 14 days and spread along the entire scaffold. At the upper scaffold surface, elongated cells were seen adhering to one another and also to the scaffold surface. These cells were elongated, aligned in parallel and contained abundant F-actin bundles suggesting a differentiated contractile phenotype. Deep into the scaffold, cells were encountered that formed actin-rich lamellipodial extensions spreading along the strut and lacked stress fibers, suggesting active cell migration along the substrate.
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PMID:Interactions of coronary artery smooth muscle cells with 3D porous polyurethane scaffolds. 1843 71

Although the myotendinous junction (MTJ) of skeletal striated muscle is well known, more detailed studies regarding the structure of the cardiac MTJ are scarce. The objective of the present study was to investigate the morphological characteristics of the MTJ in hearts of healthy and hypertensive (SHR) female rats using histological, ultrastructural and three-dimensional (SEM) methods, as well as to evaluate the expression of vinculin by immunofluorescence. In the two groups, light microscopy showed branching tendinous cords and collagen bundles penetrating the apex of the finger-like projections of the papillary muscle. SEM analysis revealed an enlarged apex of the papillary muscle in SHR which was not observed in healthy animals. The loss of force transmission appears to be compensated by the amplified connection between the papillary muscle and valvular collagen. A large number of intercalated disks close to the fiber apex, small amounts of an amorphous intercellular substance and numerous vesicles were observed in SHR. In these animals, the expression of vinculin was more marked showing a regular distribution and a pattern of transverse striations along the sarcolemma. The presence of this protein in transverse bands suggests that vinculin surrounds myofibrils in the region of the Z band. Vinculin staining was also more marked in the region of the tendinous cord-papillary muscle junctions of SHR compared to control animals. Vinculin was quantified by electrophoresis and higher amounts of this protein were observed in SHR compared to control animals.
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PMID:Structural characteristics of the tendinous cord-papillary muscle junction in healthy and hypertensive rats. 1956 20

The objective was to investigate changes, throughout the spawning season, in body size attributes and quantitative semen characteristics of wild-caught and cultivated Atlantic cod, Gadus morhua L. Sperm velocity increased significantly throughout the spawning season of cod from both origins. Curvilinear velocity (VCL; 30 sec post-activation) increased from 78.9+/-6.5 to 128.2+/-6.5 microm/sec (mean+/-SEM) between the beginning and end of the spawning season, respectively, for wild-caught cod, whereas for cultivated fish, it increased from 26.6+/-2.4 to 48.9+/-3.1 microm/sec between January and March. Spermatocrit did not undergo a significant seasonal change in wild-caught cod but did thicken for cultivated cod (24.6+/-4.2% in January to 40.5+/-4.4% in April; P<0.01). Sperm head area, perimeter, length, and width declined significantly at the end of the spawning season of cod from both origins (all P values<0.01). Seminal plasma osmolality and Na(+) ion concentration followed a dome-shaped function through the spawning season for both wild-caught and cultivated cod (P<0.05). For cultivated cod, seminal plasma pH was significantly lower at the start of the spawning season (P<0.001), whereas Ca(2+) increased then decreased (P<0.05). Body size attributes, spermatocrit, and seminal plasma constituents had significant relationships with sperm activity variables. These relationships varied as a function of time post-activation, month, and fish origin. Our findings may be used to (i) assess spermiation stage without killing males; (ii) optimize semen collection for hatchery production; (iii) characterize the potential impact of farming on sperm quality; and (iv) improve success of sperm cryopreservation and short-term storage.
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PMID:Seasonal variations in seminal plasma and sperm characteristics of wild-caught and cultivated Atlantic cod, Gadus morhua. 2004 55


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