Role of integrins in melanocyte attachment and dendricity

1994 ◽  
Vol 107 (10) ◽  
pp. 2739-2748 ◽  
Author(s):  
M. Hara ◽  
M. Yaar ◽  
A. Tang ◽  
M.S. Eller ◽  
W. Reenstra ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Cell Biology ◽  
Type Iv Collagen ◽  
Cell Attachment ◽  
Pigment Cell ◽  
Cell Types ◽  
Dependent Manner ◽  
Flow Cytometry Analysis ◽  
Type Iv ◽  
Alpha V Beta 3

Integrins are a family of proteins known to mediate attachment of cells to extracellular matrix materials. The substratum specificity and cation dependence of specific integrin heterodimers have been extensively characterized, and to a lesser degree specialized roles in cell attachment versus dendricity have been defined in some cell types. In the past decade, melanocyte attachment rate and morphology have been found to have strong substratum dependence, suggesting a major role for integrins in these processes. In order to investigate this aspect of pigment cell biology, human newborn melanocytes were subjected to flow cytometry analysis and plated on a variety of substrata under conditions known to promote or block the binding of specific integrin pairs. Melanocyte attachment to laminin and type IV collagen was promoted by Mg2+ and Mn2+ but not by Ca2+, in the range of concentrations examined. However, dendrite outgrowth from melanocytes already attached on laminin or type IV collagen was promoted by Ca2+ to a far greater degree than by Mg2+, and Mn2+ had no effect on dendrite outgrowth. Flow cytometry analysis revealed that melanocytes expressed beta 1, alpha 2, alpha 3, alpha 5, alpha 6 and alpha v integrin subunits as well as the alpha v beta 3 heterodimer. The influence of substratum on the profile of integrin expression was minimal, but alpha 6 and beta 1 integrins were observed by confocal microscopy to be expressed over the entire cell surface, while alpha 2, alpha 5 and alpha v beta 3 integrins localized along dendritic processes or at their tips. In accordance with the implications of these distribution patterns, anti-beta 1 and anti-alpha 6 integrin monoclonal antibodies blocked melanocyte attachment to laminin, while anti-alpha 2, anti-alpha 5 and anti-alpha v beta 3 inhibited dendrite outgrowth but did not block substratum attachment on either laminin or type IV collagen. On the basis of these data and the known characteristics of integrin molecules, we conclude that melanocyte attachment to laminin is mediated primarily by alpha 6 beta 1 integrin in a Ca(2+)-independent, Mg(2+)- and/or Mn(2+)-dependent manner, while dendrite outgrowth on laminin and type IV collagen requires extracellular Ca2+ and is mediated by alpha v beta 3 as well as alpha 2 and alpha 5 integrins.

scholarly journals Characterization of a type IV collagen major cell binding site with affinity to the alpha 1 beta 1 and the alpha 2 beta 1 integrins.

1991 ◽  
Vol 113 (6) ◽  
pp. 1475-1483 ◽  
Author(s):  
P Vandenberg ◽  
A Kern ◽  
A Ries ◽  
L Luckenbill-Edds ◽  
K Mann ◽  
...  
Keyword(s):  
Binding Site ◽  
Type Iv Collagen ◽  
Cell Attachment ◽  
Cell Surface Receptor ◽  
Helical Conformation ◽  
Amino Acid Residues ◽  
Cell Binding ◽  
Type Iv ◽  
Depth Study ◽  
Surface Receptor

The aim of this investigation was to identify the domains of type IV collagen participating in cell binding and the cell surface receptor involved. A major cell binding site was found in the trimeric cyanogen bromide-derived fragment CB3, located 100 nm away from the NH2 terminus of the molecule, in which the triple-helical conformation is stabilized by interchain disulfide bridges. Cell attachment assays with type IV collagen and CB3 revealed comparable cell binding activities. Antibodies against CB3 inhibited attachment on fragment CB3 completely and on type IV collagen to 80%. The ability to bind cells was strictly conformation dependent. Four trypsin derived fragments of CB3 allowed a closer investigation of the binding site. The smallest, fully active triple-helical fragment was (150)3-amino acid residues long. It contained segments of 27 and 37 residues, respectively, at the NH2 and COOH terminus, which proved to be essential for cell binding. By affinity chromatography on Sepharose-immobilized CB3, two receptor molecules of the integrin family, alpha 1 beta 1 and alpha 2 beta 1, were isolated. Their subunits were identified by sequencing the NH2 termini or by immunoblotting. The availability of fragment CB3 will allow for a more in-depth study of the molecular interaction of a short, well defined triple-helical ligand with collagen receptors alpha 1 beta 1 and alpha 2 beta 1.

scholarly journals Skin Regeneration Effect and Chemical Composition of Essential Oil from Artemisia montana

2014 ◽  
Vol 9 (11) ◽  
pp. 1934578X1400901 ◽  
Author(s):  
Mi-So Yoon ◽  
Kyung-Jong Won ◽  
Do Yoon Kim ◽  
Dae il Hwang ◽  
Seok Won Yoon ◽  
...  
Keyword(s):  
Essential Oil ◽  
Human Skin ◽  
Type Iv Collagen ◽  
Steam Distillation ◽  
Biological Effects ◽  
Skin Regeneration ◽  
Type I ◽  
Dependent Manner ◽  
Positive Effects ◽  
Type Iv

Artemisia montana Pampan (Compositae) (AMP) contains various compounds, including phenolic acids, alkaloids, and essential oil. It has been widely used in oriental medicine due to a variety of biological effects. However, the biological activity of the essential oil from AMP (AMPEO) on skin has not been investigated. In the present study, AMPEO was evaluated for its composition and its effect on cellular events (migration and proliferation) related to skin regeneration using normal human keratinocytes (HaCats). AMPEO, which was extracted by steam distillation, contained 42 components. AMPEO increased proliferation in HaCats in a dose-dependent manner (EC 50, 8.5 ng/mL) and did not affect migration. AMPEO also enhanced the phosphorylation of Akt and ERK 1/2 and induced the synthesis of type IV collagen, but not type I collagen in HaCats. In addition, AMPEO promoted wound closure in the dorsal side skin of rat tail. These results demonstrated that AMPEO extracted by steam distillation induced proliferation and synthesis of type IV collagen in human skin keratinocytes, and may thereby exert positive effects on skin regeneration and wound healing in human skin.

Selective estrogen receptor modulators suppress mesangial cell collagen synthesis

2000 ◽  
Vol 279 (2) ◽  
pp. F309-F318 ◽  
Author(s):  
Joel Neugarten ◽  
Anjali Acharya ◽  
Jun Lei ◽  
Sharon Silbiger
Keyword(s):  
Estrogen Receptor ◽  
Collagen Synthesis ◽  
Type Iv Collagen ◽  
Mesangial Cell ◽  
Type I ◽  
Dependent Manner ◽  
Type Iv ◽  
Estrogen Receptor Modulators ◽  
Receptor Modulators ◽  
Dose Dependent

Estrogen receptor modulators (SERMs) are “designer drugs” that exert estrogen-like actions in some cells but not in others. We examined the effects of the SERMs LY-117018 (an analog of raloxifene) and tamoxifen on mesangial cells synthesis of type I and type IV collagen. We found that LY-117018 and tamoxifen suppressed mesangial cell type IV collagen gene transcription and type IV collagen protein synthesis in a dose-dependent manner, with a potency identical to that of estradiol. Type I collagen synthesis was also suppressed by LY-117018 in a dose-dependent manner with a potency identical to that of estradiol but greater than that of tamoxifen. Genistein, which selectively binds to estrogen receptor-β in nanomolar concentrations, suppressed type I and type IV collagen synthesis, suggesting that estrogen receptor-β mediates the effects of estrogen on collagen synthesis. Because matrix accumulation is central to the development of glomerulosclerosis, second-generation SERMs may prove clinically useful in ameliorating progressive renal disease without the adverse effects of estrogen on reproductive tissues.

scholarly journals Signal transduction for chemotaxis and haptotaxis by matrix molecules in tumor cells.

1990 ◽  
Vol 110 (4) ◽  
pp. 1427-1438 ◽  
Author(s):  
S Aznavoorian ◽  
M L Stracke ◽  
H Krutzsch ◽  
E Schiffmann ◽  
L A Liotta
Keyword(s):  
Protein Synthesis ◽  
Matrix Protein ◽  
Type Iv Collagen ◽  
De Novo ◽  
Protein Synthesis Inhibitor ◽  
Dependent Manner ◽  
Recognition Sequence ◽  
Synthesis Inhibitor ◽  
Concentration Dependent Manner ◽  
Type Iv

Transduction of signals initiating motility by extracellular matrix (ECM) molecules differed depending on the type of matrix molecule and whether the ligand was in solution or bound to a substratum. Laminin, fibronectin, and type IV collagen stimulated both chemotaxis and haptotaxis of the A2058 human melanoma cell line. Peak chemotactic responses were reached at 50-200 nM for laminin, 50-100 nM for fibronectin, and 200-370 nM for type IV collagen. Checkerboard analysis of each attractant in solution demonstrated a predominantly directional (chemotactic) response, with a minor chemokinetic component. The cells also migrated in a concentration-dependent manner to insoluble step gradients of substratum-bound attractant (haptotaxis). The haptotactic responses reached maximal levels at coating concentrations of 20 nM for laminin and type IV collagen, and from 30 to 45 nM for fibronectin. Pretreatment of cells with the protein synthesis inhibitor, cycloheximide (5 micrograms/ml), resulted in a 5-30% inhibition of both chemotactic and haptotactic responses to each matrix protein, indicating that de novo protein synthesis was not required for a significant motility response. Pretreatment of cells with 50-500 micrograms/ml of synthetic peptides containing the fibronectin cell-recognition sequence GRGDS resulted in a concentration-dependent inhibition of fibronectin-mediated chemotaxis and haptotaxis (70-80% inhibition compared to control motility); negative control peptide GRGES had only a minimal effect. Neither GRGDS nor GRGES significantly inhibited motility to laminin or type IV collagen. Therefore, these results support a role for the RGD-directed integrin receptor in both types of motility response to fibronectin. After pretreatment with pertussis toxin (PT), chemotactic responses to laminin, fibronectin, and type IV collagen were distinctly different. Chemotaxis to laminin was intermediate in sensitivity; chemotaxis to fibronectin was completely insensitive; and chemotaxis to type IV collagen was profoundly inhibited by PT. In marked contrast to the inhibition of chemotaxis, the hepatotactic responses to all three ligands were unaffected by any of the tested concentrations of PT. High concentrations of cholera toxin (CT; 10 micrograms/ml) or the cAMP analogue, 8-Br-cAMP (0.5 mM), did not significantly affect chemotactic or haptotactic motility to any of the attractant proteins, ruling out the involvement of cAMP in the biochemical pathway initiating motility in these cells. The sensitivity of chemotaxis induced by laminin and type IV collagen, but not fibronectin, to PT indicates the involvement of a PT-sensitive G protein in transduction of the signals initiating motility to soluble laminin and type IV collagen.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Characterization of multiple adhesive and counteradhesive domains in the extracellular matrix protein cytotactin.

1992 ◽  
Vol 119 (3) ◽  
pp. 663-678 ◽  
Author(s):  
A L Prieto ◽  
C Andersson-Fisone ◽  
K L Crossin
Keyword(s):  
Extracellular Matrix ◽  
Cell Attachment ◽  
Cell Types ◽  
Expression Vectors ◽  
Extracellular Matrix Protein ◽  
Dependent Manner ◽  
Type Iii ◽  
Fibronectin Type Iii ◽  
Fibronectin Type ◽  
Better Than

The extracellular matrix molecule cytotactin is a multidomain protein that plays a role in cell migration, proliferation, and differentiation during development. To analyze the structure-function relationships of the different domains of this glycoprotein, we have prepared a series of fusion constructs in bacterial expression vectors. Results obtained using a number of adhesion assays suggest that at least four independent cell binding regions are distributed among the various cytotactin domains. Two of these are adhesive; two others appear to be counteradhesive in that they inhibit cell attachment to otherwise favorable substrates. The adhesive regions were mapped to the fibronectin type III repeats II-VI and the fibrinogen domain. The morphology of the cells plated onto these adhesive fragments differed; the cells spread on the fibronectin type III repeats as they do on fibronectin, but remained round on the fibrinogen domain. The counteradhesive properties of the molecule were mapped to the EGF-like repeats and the last two fibronectin type III repeats, VII-VIII. The latter region also contained a cell attachment activity that was observed only after proteolysis of the cells. Several cell types were used in these analyses, including fibroblasts, neurons, and glia, all of which are known to bind to cytotactin. The different domains exert their effects in a concentration-dependent manner and can be inhibited by an excess of the soluble molecule, consistent with the hypothesis that the observed properties are mediated by specific receptors. Moreover, it appears that some of these receptors are restricted to particular cell types. For example, glial cells bound better than neurons to the fibrinogen domain and fibroblasts bound better than glia and neurons to the EGF fragment. These results provide a basis for understanding the multiple activities of cytotactin and a framework for isolating different receptors that mediate the various cellular responses to this molecule.

Physiology and Cell Biology Update: Mechanisms of Type IV Collagen Gene Regulation

1991 ◽  
Vol 18 (1) ◽  
pp. 134-139 ◽  
Author(s):  
Leslie A. Bruggeman ◽  
Satoshi Horikoshi ◽  
Peter D. Burbelo ◽  
Yoshihiko Yamada ◽  
Paul E. Klotman
Keyword(s):  
Gene Regulation ◽  
Cell Biology ◽  
Type Iv Collagen ◽  
Collagen Gene ◽  
Type Iv

Integrins inhibit LPS-induced DNA strand breakage in cultured lung endothelial cells

1996 ◽  
Vol 270 (4) ◽  
pp. L689-L694 ◽  
Author(s):  
D. G. Hoyt ◽  
R. J. Mannix ◽  
M. E. Gerritsen ◽  
S. C. Watkins ◽  
J. S. Lazo ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Type Iv Collagen ◽  
Cell Types ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Dna Breakage ◽  
Type Iv ◽  
Strand Breakage ◽  
Lung Endothelial Cells ◽  
Dna Strand ◽  
Dna Strand Breakage

Collagen inhibits acute DNA strand breakage and apoptosis in sheep pulmonary artery endothelial cells (SPAEC) treated with lipopolysaccharide (LPS). Here we tested the ability of major basement membrane components, type IV collagen, laminin and fibronectin, and integrin ligands and anti-integrin antibodies to inhibit DNA breakage caused by LPS in SPAEC and BALB/c murine lung endothelial cells (MLEC). In situ labeling of DNA strand breaks with terminal deoxynucleotidyl transferase revealed similar DNA breakage in attached SPAEC and MLEC within 2 h after incubation with 1 microgram LPS/ml. Acute DNA strand breakage was reduced in cells plated on gelatin, type IV collagen, laminin, cellular fibronectin, or plasma fibronectin. DNA breakage was also suppressed by plating cells on surfaces coated with the integrin ligand hexapeptide, GRGDSP (40 micrograms/cm2), but not with GRADSP. LPS-induced DNA strand breakage was inhibited in MLEC plated on surfaces coated with antibodies to murine alpha 5-, beta 1, or beta 3-integrin subunits. Addition of anti-integrin antibodies, but not GRGDSP, to the medium above cell monolayers inhibited strand breakage. Despite similar acute DNA breakage, MLEC exhibited less detachment and apoptosis than SPAEC, consistent with a difference in the sensing or processing systems for apoptosis in these two cell types. These results demonstrate that extracellular matrices and integrin activation can inhibit the genotoxicity of LPS.

Propranolol induced apoptosis and autophagy via the ROS/JNK signaling pathway in human ovarian cancer

2020 ◽  
Author(s):  
Shujun Zhao ◽  
Suzhen Fan ◽  
Yanyu Shi ◽  
Hongyan Ren ◽  
Hanqing Hong ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Flow Cytometry ◽  
Signaling Pathway ◽  
Cell Apoptosis ◽  
Human Ovarian Cancer ◽  
Dependent Manner ◽  
Flow Cytometry Analysis ◽  
Jnk Signaling ◽  
Jnk Signaling Pathway ◽  
Induced Apoptosis

Abstract Background: Propranolol has a significant anti-cancer effect on various cancers. The present study aimed to investigate the underlying mechanism behind the therapeutic effect of Propranolol on the ovarian cancer.Materials and methods: The effect of Propranolol on cell viability was examined by MTT analysis. Cellular apoptosis was evaluated by flow cytometry analysis. Autophagy was defined by autophagosome observed by confocal microscopy after infected with GFP-LC3 adenovirus. In addition, the expression of marker proteins involved in cell apoptosis, autophagy, and ROS/JNK signaling pathway were estimated by Western Blotting assay.Results: Propranolol significantly reduced the viability of human ovarian cancer cell lines SKOV-3 and A2780 in a dose- and time-dependent manner. Flow cytometry analysis revealed that Propranolol induced the cell cycle arrest at G2/M phase and resulted in apoptosis. Moreover, autophagy inhibitor 3-MA markedly enhanced the Propranolol-induced apoptosis. In addition, reactive oxygen species (ROS) was demonstrated dramatically increased after Propranolol treatment and Propranolol activated the phosphorylation of JNK. What is more, p38 inhibitor SB203580 and JNK inhibitor SP600125 attenuated the upregulated expression of LC3-II and cleaved-caspase-3 by the effect of Propranolol. ROS exclusive inhibitor antioxidant N-acetyl cysteine (NAC) weaken the phosphorylation of JNK proteins induced by Propranolol.Conclusions：In summary, our results suggested that Propranolol induced cell apoptosis and protective autophagy through the ROS/JNK signaling pathway in human ovarian cancer cells.

Sustained ERK phosphorylation is necessary but not sufficient for MMP-9 regulation in endothelial cells: involvement of Ras-dependent and -independent pathways

2000 ◽  
Vol 113 (23) ◽  
pp. 4319-4330 ◽  
Author(s):  
E. Genersch ◽  
K. Hayess ◽  
Y. Neuenfeld ◽  
H. Haller
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Signal Transduction Pathway ◽  
Cell Types ◽  
Tnf Alpha ◽  
Dependent Manner ◽  
Necrosis Factor Alpha ◽  
Type Iv ◽  
Erk Phosphorylation ◽  
Umbilical Vein Endothelial Cells

Endothelial expression of matrix metalloproteinase-9 (MMP-9), which degrades native type IV collagen, was implicated as a prerequisite for angiogenesis. Therefore, the aim of this study was to determine signaling requirements that regulate MMP-9 expression in endothelial cells. Both, primary and permanent human umbilical vein endothelial cells (HUVEC and ECV304, respectively) were stimulated with phorbol 12-myristate 13-acetate (PMA) and the cytokine tumor necrosis factor-(alpha) (TNF(alpha)) to induce MMP-9 expression. While both cell types responded to PMA at the protein, mRNA and promoter level by induction of MMP-9, TNF(alpha) caused this response only in ECV304. Inhibitors specific for mitogen-activated protein/ERK kinase 1/2 (MEK1/2), protein kinase C (PKC), and Ras and co-transfections of wild-type and mutant Raf were used to elucidate the signaling cascades involved. Thus, we could show that the Raf/MEK/ERK cascade is mainly responsible for MMP-9 induction in endothelial cells and that this cascade is regulated independently of PKC and Ras subsequent to TNF(alpha) stimulation and in a PKC-dependent manner as a result of PMA treatment. In addition, PMA triggers a Ras-dependent signal transduction pathway bypassing the phosphorylation of ERK. Finally, we provide evidence that sustained phosphorylation of ERK1/2 is necessary but not sufficient for expression of MMP-9.

scholarly journals Ligand-specific, transient interaction between integrins and calreticulin during cell adhesion to extracellular matrix proteins is dependent upon phosphorylation/dephosphorylation events

1999 ◽  
Vol 340 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Marc G. COPPOLINO ◽  
Shoukat DEDHAR
Keyword(s):  
Okadaic Acid ◽  
Cell Attachment ◽  
Specific Interaction ◽  
Cell Types ◽  
Collagen Iv ◽  
Jurkat Cells ◽  
Mitogen Activated Protein Kinase ◽  
Collagen Type Iv ◽  
Type Iv ◽  
Mitogen Activated Protein

As transmembrane heterodimers, integrins bind to both extracellular ligands and intracellular proteins. We are currently investigating the interaction between integrins and the intracellular protein calreticulin. A prostatic carcinoma cell line (PC-3) was used to demonstrate that calreticulin can be found in the α3 immunoprecipitates of cells plated on collagen type IV, but not when plated on vitronectin. Conversely, αv immunoprecipitates contained calreticulin only when cells were plated on vitronectin, i.e. not when plated on collagen IV. The interactions between these integrins and calreticulin were independent of actin cytoskeleton assembly and were transient, being maximal approx. 10-30 min after the cells came into contact with the substrates prior to complete cell spreading and formation of firm adhesive contacts. We demonstrate that okadaic acid, an inhibitor of intracellular serine/threonine protein phosphatases, inhibited the α3β1-mediated adhesion of PC-3 cells to collagen IV and the α2β1-mediated attachment of Jurkat cells to collagen I. This inhibition by okadaic acid was accompanied by inhibition of the ligand-specific interaction of calreticulin with the respective integrins in the two cell types. Additionally, we found that pharmacological inhibition of mitogen-activated protein kinase kinase (MEK) resulted in prolongation of the calreticulin-integrin interaction, and enhancement of PC-3 cell attachment to collagen IV. We conclude that calreticulin interacts transiently with integrins during cell attachment and spreading. This interaction depends on receptor occupation, is ligand-specific, and can be modulated by protein phosphatase and MEK activity.

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