The Experts below are selected from a list of 68949 Experts worldwide ranked by ideXlab platform
Oksana Shynlova - One of the best experts on this subject based on the ideXlab platform.
-
Static Mechanical Loading Influences the Expression of ExtraCellular Matrix and Cell Adhesion Proteins in Vaginal Cells Derived From Premenopausal Women With Severe Pelvic Organ Prolapse
Reproductive Sciences, 2016Co-Authors: Hala Kufaishi, May Alarab, Harold Drutz, Oksana ShynlovaAbstract:Introduction Primary human vaginal Cells derived from women with severe pelvic organ prolapse (POP-HVCs) demonstrate altered Cellular characteristics as compared to Cells derived from asymptomatic women (control-HVCs). Using computer-controllable FlexCell stretch unit, we examined whether POP-HVCs react differently to mechanical loading as compared to control-HVCs by the expression of extraCellular matrix (ECM) components, Cell–ECM Adhesion Proteins, and ECM degrading and maturating enzymes. Methods Vaginal tissue biopsies from premenopausal patients with Pelvic Organ Prolapse Quantification System stage ≥3 (n = 8) and asymptomatic controls (n = 7) were collected during vaginal hysterectomy or repair. Human vaginal Cells were isolated by enzymatic digestion, seeded on collagen (COLI)-coated plates, and stretched (24 hours, 25% elongation). Total RNA was extracted, and 84 genes were screened using Human ECM and Adhesion Molecules polymerase chain reaction array; selected genes were verified by quantitative reverse transcription-polymerase chain reaction. Stretch-conditioned media (SCM) were collected and analyzed by protein array, immunoblotting, and zymography. Results In mechanically stretched control-HVCs, transcript levels of integrins (ITGA1, ITGA4, ITGAV, and ITGB1) and matrix metalloproteinases (MMPs) 2, 8, and 13 were downregulated ( P < .05); in POP-HVCs, MMP1, MMP3, and MMP10, ADAMTS8 and 13, tissue inhibitor of metalloproteinases (TIMPs) 1 to 3, ITGA2, ITGA4, ITGA6, ITGB1, contactin (CNTN1), catenins (A1 and B1), and laminins (A3 and C1) were significantly upregulated, whereas COLs (1, 4, 5, 6, 11, and 12) and LOXL1 were downregulated. Human vaginal Cells massively secrete MMPs and TIMPs Proteins; MMP1, MMP8, MMP9 protein expression and MMP2 gelatinase activity were increased, whereas TIMP2 decreased in SCM from POP-HVCs compared to control-HVCs. Conclusions Primary human vaginal Cells derived from women with severe pelvic organ prolapse and control-HVCs react differentially to in vitro mechanical stretch. Risk factors that induce stretch may alter ECM composition and Cell–ECM interaction in pelvic floor tissue leading to the abatement of pelvic organ support and subsequent POP development.
-
static mechanical loading influences the expression of extraCellular matrix and Cell Adhesion Proteins in vaginal Cells derived from premenopausal women with severe pelvic organ prolapse
Reproductive Sciences, 2016Co-Authors: Hala Kufaishi, May Alarab, Harold Drutz, Oksana Shynlova, Stephen J LyeAbstract:Introduction:Primary human vaginal Cells derived from women with severe pelvic organ prolapse (POP-HVCs) demonstrate altered Cellular characteristics as compared to Cells derived from asymptomatic women (control-HVCs). Using computer-controllable FlexCell stretch unit, we examined whether POP-HVCs react differently to mechanical loading as compared to control-HVCs by the expression of extraCellular matrix (ECM) components, Cell–ECM Adhesion Proteins, and ECM degrading and maturating enzymes.Methods:Vaginal tissue biopsies from premenopausal patients with Pelvic Organ Prolapse Quantification System stage ≥3 (n = 8) and asymptomatic controls (n = 7) were collected during vaginal hysterectomy or repair. Human vaginal Cells were isolated by enzymatic digestion, seeded on collagen (COLI)-coated plates, and stretched (24 hours, 25% elongation). Total RNA was extracted, and 84 genes were screened using Human ECM and Adhesion Molecules polymerase chain reaction array; selected genes were verified by quantitative ...
Sanjeevi Sivasankar - One of the best experts on this subject based on the ideXlab platform.
-
Different roles of cadherins in the assembly and structural integrity of the desmosome complex.
Journal of Cell Science, 2014Co-Authors: Molly Lowndes, Omer Shafraz, Sabyasachi Rakshit, Sanjeevi Sivasankar, Nicolas Borghi, Robert Harmon, Kathleen Green, W. James NelsonAbstract:: Adhesion between Cells is established by the formation of specialized interCellular junctional complexes, such as desmosomes. Desmosomes comprise two members of the cadherin superfamily of Cell Adhesion Proteins, desmocollin (Dsc) and desmoglein (Dsg), but their combinatorial roles in desmosome assembly is not understood. To uncouple desmosome assembly from other Cell-Cell Adhesion complexes, we used micro-patterned substrates of Dsc2aFc and/or Dsg2Fc and collagen IV; we show that Dsc2aFc, but not Dsg2Fc, was necessary and sufficient to recruit desmosome-specific desmoplakin into desmosome puncta and produce strong adhesive binding. Single Molecule Force Spectroscopy showed that monomeric Dsc2a, but not Dsg2, formed Ca(2+)-dependent homophilic bonds, and that Dsg2 formed Ca(2+)-independent heterophilic bonds with Dsc2a. A W2A mutation in Dsc2a inhibited Ca(2+)-dependent homophilic binding, similar to classical cadherins, and Dsc2aW2A, but not Dsg2W2A, was excluded from desmosomes in MDCK Cells. These results indicate that Dsc2a, not Dsg2, is required for desmosome assembly via homophilic Ca(2+)- and W2/strand swap-dependent binding, and that Dsg2 may be involved later in regulating a switch to Ca(2+)-independent Adhesion in mature desmosomes.
-
Characterizing the Interaction of Desmosomal Cadherins at Single Molecule Level
Biophysical Journal, 2014Co-Authors: Omer Shafraz, Sabyasachi Rakshit, Molly Lowndes, W. James Nelson, Sanjeevi SivasankarAbstract:Desmosomes are Cell-Cell Adhesion complexes that are present in tissues that resist mechanical stress. They are mainly composed of two adhesive Proteins, which are members of the cadherin superfamily of Cell Adhesion Proteins, desmocollin (Dsc) and desmoglein (Dsg). However, the role of these Proteins in desmosomal Adhesion is unclear. Here, we use the single molecule force spectroscopy with an Atomic Force Microscope (AFM-FS) to characterize the interactions of type-2 isoforms of desmocollin (Dsc2) and desmoglein (Dsg2). We show that Dsc2 forms Ca2+ dependent homophilic bonds by swapping a conserved Tryptophan (Trp) residue between opposing binding partners; mutating this Trp inhibits Ca2+ dependent homophilic binding. In contrast, Dsg2 forms Ca2+ independent heterophilic bonds with Dsc2 via a mechanism that does not involve Trp strand-swapping.Previous studies suggest that desmosome formation requires the presence of classical cadherins at the site of desmosome assembly. This suggests a cross-talk between desmosomal and classical cadherins at Cell-Adhesion contacts. We therefore used AFM-FS to test if Dsc2 and Dsg2 interact with E-cadherin, a classical cadherin present in the epithelium. Our data shows that while Dsc2 does not bind to E-cadherin in the presence of Ca2+, Dsg2 forms Ca2+ independent complexes with E-cadherin. Using cadherin mutants we show that the interactions between Dsg2 and E-cadherin occur via a previously uncharacterized binding interface that does not involve either Trp strand-swapping or X-dimer formation (two well established classical cadherin binding mechanisms).
-
biomechanics of Cell Adhesion how force regulates the lifetime of adhesive bonds at the single molecule level
Physical Chemistry Chemical Physics, 2014Co-Authors: Sabyasachi Rakshit, Sanjeevi SivasankarAbstract:Cell Adhesion Proteins play critical roles in positioning Cells during development, segregating Cells into distinct tissue compartments and in maintaining tissue integrity. The principle function of these Proteins is to bind Cells together and resist mechanical force. Adhesive Proteins also enable migrating Cells to adhere and roll on surfaces even in the presence of shear forces exerted by fluid flow. Recently, several experimental and theoretical studies have provided quantitative insights into the physical mechanisms by which Adhesion Proteins modulate their unbinding kinetics in response to tensile force. This perspective reviews these biophysical investigations. We focus on single molecule studies of cadherins, selectins, integrins, the von Willebrand factor and FimH Adhesion Proteins; the effect of mechanical force on the lifetime of these interactions has been extensively characterized. We review both theoretical models and experimental investigations and discuss future directions in this exciting area of research.
Sabyasachi Rakshit - One of the best experts on this subject based on the ideXlab platform.
-
Different roles of cadherins in the assembly and structural integrity of the desmosome complex.
Journal of Cell Science, 2014Co-Authors: Molly Lowndes, Omer Shafraz, Sabyasachi Rakshit, Sanjeevi Sivasankar, Nicolas Borghi, Robert Harmon, Kathleen Green, W. James NelsonAbstract:: Adhesion between Cells is established by the formation of specialized interCellular junctional complexes, such as desmosomes. Desmosomes comprise two members of the cadherin superfamily of Cell Adhesion Proteins, desmocollin (Dsc) and desmoglein (Dsg), but their combinatorial roles in desmosome assembly is not understood. To uncouple desmosome assembly from other Cell-Cell Adhesion complexes, we used micro-patterned substrates of Dsc2aFc and/or Dsg2Fc and collagen IV; we show that Dsc2aFc, but not Dsg2Fc, was necessary and sufficient to recruit desmosome-specific desmoplakin into desmosome puncta and produce strong adhesive binding. Single Molecule Force Spectroscopy showed that monomeric Dsc2a, but not Dsg2, formed Ca(2+)-dependent homophilic bonds, and that Dsg2 formed Ca(2+)-independent heterophilic bonds with Dsc2a. A W2A mutation in Dsc2a inhibited Ca(2+)-dependent homophilic binding, similar to classical cadherins, and Dsc2aW2A, but not Dsg2W2A, was excluded from desmosomes in MDCK Cells. These results indicate that Dsc2a, not Dsg2, is required for desmosome assembly via homophilic Ca(2+)- and W2/strand swap-dependent binding, and that Dsg2 may be involved later in regulating a switch to Ca(2+)-independent Adhesion in mature desmosomes.
-
Characterizing the Interaction of Desmosomal Cadherins at Single Molecule Level
Biophysical Journal, 2014Co-Authors: Omer Shafraz, Sabyasachi Rakshit, Molly Lowndes, W. James Nelson, Sanjeevi SivasankarAbstract:Desmosomes are Cell-Cell Adhesion complexes that are present in tissues that resist mechanical stress. They are mainly composed of two adhesive Proteins, which are members of the cadherin superfamily of Cell Adhesion Proteins, desmocollin (Dsc) and desmoglein (Dsg). However, the role of these Proteins in desmosomal Adhesion is unclear. Here, we use the single molecule force spectroscopy with an Atomic Force Microscope (AFM-FS) to characterize the interactions of type-2 isoforms of desmocollin (Dsc2) and desmoglein (Dsg2). We show that Dsc2 forms Ca2+ dependent homophilic bonds by swapping a conserved Tryptophan (Trp) residue between opposing binding partners; mutating this Trp inhibits Ca2+ dependent homophilic binding. In contrast, Dsg2 forms Ca2+ independent heterophilic bonds with Dsc2 via a mechanism that does not involve Trp strand-swapping.Previous studies suggest that desmosome formation requires the presence of classical cadherins at the site of desmosome assembly. This suggests a cross-talk between desmosomal and classical cadherins at Cell-Adhesion contacts. We therefore used AFM-FS to test if Dsc2 and Dsg2 interact with E-cadherin, a classical cadherin present in the epithelium. Our data shows that while Dsc2 does not bind to E-cadherin in the presence of Ca2+, Dsg2 forms Ca2+ independent complexes with E-cadherin. Using cadherin mutants we show that the interactions between Dsg2 and E-cadherin occur via a previously uncharacterized binding interface that does not involve either Trp strand-swapping or X-dimer formation (two well established classical cadherin binding mechanisms).
-
biomechanics of Cell Adhesion how force regulates the lifetime of adhesive bonds at the single molecule level
Physical Chemistry Chemical Physics, 2014Co-Authors: Sabyasachi Rakshit, Sanjeevi SivasankarAbstract:Cell Adhesion Proteins play critical roles in positioning Cells during development, segregating Cells into distinct tissue compartments and in maintaining tissue integrity. The principle function of these Proteins is to bind Cells together and resist mechanical force. Adhesive Proteins also enable migrating Cells to adhere and roll on surfaces even in the presence of shear forces exerted by fluid flow. Recently, several experimental and theoretical studies have provided quantitative insights into the physical mechanisms by which Adhesion Proteins modulate their unbinding kinetics in response to tensile force. This perspective reviews these biophysical investigations. We focus on single molecule studies of cadherins, selectins, integrins, the von Willebrand factor and FimH Adhesion Proteins; the effect of mechanical force on the lifetime of these interactions has been extensively characterized. We review both theoretical models and experimental investigations and discuss future directions in this exciting area of research.
Jackie Papkoff - One of the best experts on this subject based on the ideXlab platform.
-
Wnt-1 regulates free pools of catenins and stabilizes APC-catenin complexes.
Molecular and Cellular Biology, 1996Co-Authors: Jackie Papkoff, Bonnee Rubinfeld, B Schryver, Paul PolakisAbstract:The Wnt-1 proto-oncogene induces the accumulation of beta-catenin and plakoglobin, two related Proteins that associate with and functionally modulate the cadherin Cell Adhesion Proteins. Here we have investigated the effects of Wnt-1 expression on the tumor suppressor protein APC, which also associates with catenins. Expression of Wnt-1 in two different Cell lines greatly increased the stability of APC-catenin complexes. The steady-state levels of both catenins and APC were elevated by Wnt-1, and the half-lives of both beta-catenin and plakoglobin associated with APC were also markedly increased. The stabilization of catenins by Wnt-1 was primarily the result of a selective increase in the amount of uncomplexed, monomeric beta-catenin and plakoglobin, detected both by affinity precipitation and size-exclusion chromatography of Cell extracts. Exogenous expression of beta-catenin was possible in Cells already responding to Wnt-1 but not in the parental Cells, suggesting that Wnt-1 inhibits an essential regulatory mechanism for beta-catenin turnover. APC has the capacity to oppose this Wnt-1 effect in experiments in which overexpression of the central region of APC significantly reduced the size of the monomeric pool of beta-catenin induced by Wnt-1. Thus, the Wnt-1 signal transduction pathway leads to the accumulation of monomeric catenins and stabilization of catenin complex formation with both APC and cadherins.
-
wnt 1 modulates Cell Cell Adhesion in mammalian Cells by stabilizing beta catenin binding to the Cell Adhesion protein cadherin
Journal of Cell Biology, 1994Co-Authors: L Hinck, W J Nelson, Jackie PapkoffAbstract:Wnt-1 homologs have been identified in invertebrates and vertebrates and play important roles in Cellular differentiation and organization. In Drosophila, the products of the segment polarity genes wingless (the Wnt-1 homolog) and armadillo participate in a signal transduction pathway important for Cellular boundary formation in embryonic development, but functional interactions between the Proteins are unknown. We have examined Wnt-1 function in mammalian Cells in which armadillo (beta-catenin and plakoglobin) is known to bind to and regulate cadherin Cell Adhesion Proteins. We show that Wnt-1 expression results in the accumulation of beta-catenin and plakoglobin. In addition, binding of beta-catenin to the Cell Adhesion protein, cadherin, is stabilized, resulting in a concomitant increase in the strength of calcium-dependent Cell-Cell Adhesion. Thus, a consequence of the functional interaction between Wnt-1 and armadillo family members is the strengthening of Cell-Cell Adhesion, which may lead to the specification of Cellular boundaries.
Harold Drutz - One of the best experts on this subject based on the ideXlab platform.
-
Static Mechanical Loading Influences the Expression of ExtraCellular Matrix and Cell Adhesion Proteins in Vaginal Cells Derived From Premenopausal Women With Severe Pelvic Organ Prolapse
Reproductive Sciences, 2016Co-Authors: Hala Kufaishi, May Alarab, Harold Drutz, Oksana ShynlovaAbstract:Introduction Primary human vaginal Cells derived from women with severe pelvic organ prolapse (POP-HVCs) demonstrate altered Cellular characteristics as compared to Cells derived from asymptomatic women (control-HVCs). Using computer-controllable FlexCell stretch unit, we examined whether POP-HVCs react differently to mechanical loading as compared to control-HVCs by the expression of extraCellular matrix (ECM) components, Cell–ECM Adhesion Proteins, and ECM degrading and maturating enzymes. Methods Vaginal tissue biopsies from premenopausal patients with Pelvic Organ Prolapse Quantification System stage ≥3 (n = 8) and asymptomatic controls (n = 7) were collected during vaginal hysterectomy or repair. Human vaginal Cells were isolated by enzymatic digestion, seeded on collagen (COLI)-coated plates, and stretched (24 hours, 25% elongation). Total RNA was extracted, and 84 genes were screened using Human ECM and Adhesion Molecules polymerase chain reaction array; selected genes were verified by quantitative reverse transcription-polymerase chain reaction. Stretch-conditioned media (SCM) were collected and analyzed by protein array, immunoblotting, and zymography. Results In mechanically stretched control-HVCs, transcript levels of integrins (ITGA1, ITGA4, ITGAV, and ITGB1) and matrix metalloproteinases (MMPs) 2, 8, and 13 were downregulated ( P < .05); in POP-HVCs, MMP1, MMP3, and MMP10, ADAMTS8 and 13, tissue inhibitor of metalloproteinases (TIMPs) 1 to 3, ITGA2, ITGA4, ITGA6, ITGB1, contactin (CNTN1), catenins (A1 and B1), and laminins (A3 and C1) were significantly upregulated, whereas COLs (1, 4, 5, 6, 11, and 12) and LOXL1 were downregulated. Human vaginal Cells massively secrete MMPs and TIMPs Proteins; MMP1, MMP8, MMP9 protein expression and MMP2 gelatinase activity were increased, whereas TIMP2 decreased in SCM from POP-HVCs compared to control-HVCs. Conclusions Primary human vaginal Cells derived from women with severe pelvic organ prolapse and control-HVCs react differentially to in vitro mechanical stretch. Risk factors that induce stretch may alter ECM composition and Cell–ECM interaction in pelvic floor tissue leading to the abatement of pelvic organ support and subsequent POP development.
-
static mechanical loading influences the expression of extraCellular matrix and Cell Adhesion Proteins in vaginal Cells derived from premenopausal women with severe pelvic organ prolapse
Reproductive Sciences, 2016Co-Authors: Hala Kufaishi, May Alarab, Harold Drutz, Oksana Shynlova, Stephen J LyeAbstract:Introduction:Primary human vaginal Cells derived from women with severe pelvic organ prolapse (POP-HVCs) demonstrate altered Cellular characteristics as compared to Cells derived from asymptomatic women (control-HVCs). Using computer-controllable FlexCell stretch unit, we examined whether POP-HVCs react differently to mechanical loading as compared to control-HVCs by the expression of extraCellular matrix (ECM) components, Cell–ECM Adhesion Proteins, and ECM degrading and maturating enzymes.Methods:Vaginal tissue biopsies from premenopausal patients with Pelvic Organ Prolapse Quantification System stage ≥3 (n = 8) and asymptomatic controls (n = 7) were collected during vaginal hysterectomy or repair. Human vaginal Cells were isolated by enzymatic digestion, seeded on collagen (COLI)-coated plates, and stretched (24 hours, 25% elongation). Total RNA was extracted, and 84 genes were screened using Human ECM and Adhesion Molecules polymerase chain reaction array; selected genes were verified by quantitative ...