Differential Downregulation of E-Cadherin and Desmoglein by Epidermal Growth Factor

Directory of Open Access Journals (Sweden)

Miquella G. Chavez

2012-01-01

Full Text Available Modulation of cell : cell junctions is a key event in cutaneous wound repair. In this study we report that activation of the epidermal growth factor (EGF receptor disrupts cel : cell adhesion, but with different kinetics and fates for the desmosomal cadherin desmoglein and for E-cadherin. Downregulation of desmoglein preceded that of E-cadherin in vivo and in an EGF-stimulated in vitro wound reepithelialization model. Dual immunofluorescence staining revealed that neither E-cadherin nor desmoglein-2 internalized with the EGF receptor, or with one another. In response to EGF, desmoglein-2 entered a recycling compartment based on predominant colocalization with the recycling marker Rab11. In contrast, E-cadherin downregulation was accompanied by cleavage of the extracellular domain. A broad-spectrum matrix metalloproteinase inhibitor protected E-cadherin but not the desmosomal cadherin, desmoglein-2, from EGF-stimulated disruption. These findings demonstrate that although activation of the EGF receptor regulates adherens junction and desmosomal components, this stimulus downregulates associated cadherins through different mechanisms.

Cyclooxygenase-2 mediated regulation of E-cadherin occurs in conventional but not early-onset gastric cancer cell lines

NARCIS (Netherlands)

Sitarz, R.; Leguit, R. J.; de Leng, W. W. J.; Morsink, F. H. M.; Polkowski, W. P.; Maciejewski, R.; Offerhaus, G. J. A.; Milne, A. N.

2009-01-01

COX-2 and E-cadherin, involved in invasion and metastasis, are molecules critical for gastric carcinogenesis. A relationship between them is documented in non-small cell lung and prostate cancer. We present novel evidence of a relationship between COX-2 and E-cadherin expression in gastric cancer.

Cooperation of distinct Rac-dependent pathways to stabilise E-cadherin adhesion.

Science.gov (United States)

Erasmus, Jennifer C; Welsh, Natalie J; Braga, Vania M M

2015-09-01

The precise mechanisms via which Rac1 is activated by cadherin junctions are not fully known. In keratinocytes Rac1 activation by cadherin junctions requires EGFR signalling, but how EGFR does so is unclear. To address which activator could mediate E-cadherin signalling to Rac1, we investigated EGFR and two Rac1 GEFs, SOS1 and DOCK180. EGFR RNAi prevented junction-induced Rac1 activation and led to fragmented localization of E-cadherin at cadherin contacts. In contrast, depletion of another EGFR family member, ErbB3, did not interfere with either process. DOCK180 RNAi, but not SOS1, prevented E-cadherin-induced Rac1 activation. However, in a strong divergence from EGFR RNAi phenotype, DOCK180 depletion did not perturb actin recruitment or cadherin localisation at junctions. Rather, reduced DOCK180 levels impaired the resistance to mechanical stress of pre-formed cell aggregates. Thus, within the same cell type, EGFR and DOCK180 regulate Rac1 activation by newly-formed contacts, but control separate cellular events that cooperate to stabilise junctions. Copyright © 2015. Published by Elsevier Inc.

Vitamin D regulates tyrosine hydroxylase expression: N-cadherin a possible mediator.

Science.gov (United States)

Cui, X; Pertile, R; Liu, P; Eyles, D W

2015-09-24

Vitamin D is a neuroactive steroid. Its genomic actions are mediated via the active form of vitamin D, 1,25(OH)2D3, binding to the vitamin D receptor (VDR). The VDR emerges in the rat mesencephalon at embryonic day 12, representing the peak period of dopaminergic cell birth. Our prior studies reveal that developmental vitamin D (DVD)-deficiency alters the ontogeny of dopaminergic neurons in the developing mesencephalon. There is also consistent evidence from others that 1,25(OH)2D3 promotes the survival of dopaminergic neurons in models of dopaminergic toxicity. In both developmental and toxicological studies it has been proposed that 1,25(OH)2D3 may modulate the differentiation and maturation of dopaminergic neurons; however, to date there is lack of direct evidence. The aim of the current study is to investigate this both in vitro using a human SH-SY5Y cell line transfected with rodent VDR and in vivo using a DVD-deficient model. Here we show that in VDR-expressing SH-SY5Y cells, 1,25(OH)2D3 significantly increased production of tyrosine hydroxylase (TH), the rate-limiting enzyme in dopamine synthesis. This effect was dose- and time-dependent, but was not due to an increase in TH-positive cell number, nor was it due to the production of trophic survival factors for dopamine neurons such as glial-derived neurotrophic factor (GDNF). In accordance with 1,25(OH)2D3's anti-proliferative actions in the brain, 1,25(OH)2D3 reduced the percentage of dividing cells from approximately 15-10%. Given the recently reported role of N-cadherin in the direct differentiation of dopaminergic neurons, we examined here whether it may be elevated by 1,25(OH)2D3. We confirmed this in vitro and more importantly, we showed DVD-deficiency decreases N-cadherin expression in the embryonic mesencephalon. In summary, in our in vitro model we have shown 1,25(OH)2D3 increases TH expression, decreases proliferation and elevates N-cadherin, a potential factor that mediates these processes

Activation of estrogen receptor beta (ERβ) regulates the expression of N-cadherin, E-cadherin and β-catenin in androgen-independent prostate cancer cells.

Science.gov (United States)

Silva, Rafael de Souza; Lombardi, Ana Paola G; de Souza, Deborah Simão; Vicente, Carolina M; Porto, Catarina S

2018-03-01

The aim of the present study was to investigate the impact of the activation of estrogen receptors on expression and localization of N-cadherin, E-cadherin and non-phosphorylated β-catenin in androgen-independent prostate cancer cells (PC-3 and DU-145) and in human post pubertal prostate epithelial cells (PNT1A). Expression of N-cadherin was detected in PNT1A and PC-3 cells, but not in DU-145 cells. E-cadherin was detected only in DU-145 cells and β-catenin was detected in all cells studied. N-cadherin and β-catenin were located preferentially in the cellular membrane of PNT1A cells and in the cytoplasm of PC-3 cells. E-cadherin and β-catenin were located preferentially in the cellular membrane of DU-145 cells. 17β-estradiol (E2) or the ERα-selective agonist PPT did not affect the content and localization of N-cadherin in PC-3 and PNT1A cells or E-cadherin in DU-145 cells. In PC-3 cells, ERβ-selective agonist DPN decreased the expression of N-cadherin. DPN-induced downregulation of N-cadherin was blocked by pretreatment with the ERβ-selective antagonist (PHTPP), indicating that ERβ1 is the upstream receptor regulating the expression of N-cadherin. In DU-145 cells, the activation of ERβ1 by DPN increased the expression of E-cadherin. Taken together, these results suggest that activation of ERβ1 is required to maintain an epithelial phenotype in PC-3 and DU-145 cells. The activation of ERβ1 also increased the expression of β-catenin in cytoplasm of PC-3 and in the cellular membrane of DU-145 cells. In conclusion, our results indicate differential expression and localization of N-cadherin, E-cadherin and β-catenin in androgen-independent prostate cancer cells. The reduction of N-cadherin content by activation of ERβ, exclusively observed in androgen-independent prostate cancer cells (PC-3), may be related to the activation of signaling pathways, such as the release of β-catenin into the cytoplasm, translocation of β-catenin to the nucleus and

[Epithelial cadherins and associated molecules in invasive lobular breast cancer].

Science.gov (United States)

Brilliant, Yu M; Brilliant, A A; Sazonov, S V

to estimate the expression of cell adhesion molecules E- and P-cadherin, as well as that of cadherin-catenin complexes in invasive lobular breast cancer (BC) cells. 250 cases of postoperative material from patients diagnosed with invasive lobular BC were studied. The expressions of cell adhesion molecules E-cadherin, P-cadherin, β-catenin, p120 catenin, and vimentin were determined by immunohistochemical assay in all cases. The examined cases were divided into molecular biological subtypes, based on the evaluation of estrogen receptors (ER), progesterone receptors (PR), HER-2/neu, and Ki-67 proliferative index. The membrane expression of E-cadherin on the tumor cells was found to be preserved in 93%; the cytoplasmic expression of β-catenin and p120-catenin appeared in 60 and 72% of cases, respectively. The expression of P-cadherin was detected in 82% of cases. The coexpression of E- and P-cadherin was noted in 90% of all the examined cases. There was a correlation between the expression of E- and P-cadherins (V=0.34; pcancer and its metastasis.

Interplay between CKS2, N-cadherin, and PD-ECGF in Non-Schistosomal and Schistosomal-Associated Bladder Cancer: A Prospective Comparative Study in the Egyptian Population

Directory of Open Access Journals (Sweden)

Sanaa Shawky

2017-01-01

Full Text Available Background: The current study investigated the possible role of the cell cycle regulator, cyclin-dependent kinases regulatory subunit-2; the angiogenic factor, plateletderived endothelial cell growth factor; and the cell adhesive molecule, neural cadherin, as prognostic factors in schistosomal and non-schistosomal-associated urothelial carcinomas. We also investigated the possible correlation between cyclin-dependent kinases regulatory subunit-2, platelet-derived endothelial cell growth factor, neural cadherin, tumor grade, and stage. Methods: The study included 40 patients with primary bladder cancer (25 nonschistosomal- associated and 15 schistosomal-associated who had no prior anticancer treatment. Tumor specimens were collected at the time of the transurethral resection. The vivid portions of the resected tumors were subjected to routine pathological examinations to determine stage, grade, and schistosomal infestation. Control bladder tissues (5 cases were obtained by cystoscopic biopsies from patients who underwent transurethral resection of the prostate. Platelet-derived endothelial cell growth factor and neural cadherin protein expressions were evaluated by immunohistochemical staining. RNA was extracted, reverse transcribed, and amplified by PCR using cyclindependent kinases regulatory subunit-2 specific primers. Relative expression was detected by a comparison of the expression in normal and tumor samples relative to GAPDH (housekeeping gene expression. Results:We detected a positive correlation between neural cadherin and plateletderived endothelial cell growth factor proteins in schistosomal-associated and non-schistosomal-associated bladder cancer. Significant overexpression of relative cyclin-dependent kinases regulatory subunit-2 gene, neural cadherin, and plateletderived endothelial cell growth factor proteins were detected in invasive stages and higher grades of bladder cancer. Differential expressions of neural cadherin and

The minimal essential unit for cadherin-mediated intercellular adhesion comprises extracellular domains 1 and 2

DEFF Research Database (Denmark)

Shan, Weisong; Yagita, Yoshiki; Wang, Zhaohui

2004-01-01

of the extracellular domains of N-cadherin and produced various cell lines to examine adhesion properties. We show that the first domain of N-cadherin alone on the cell surface fails to generate adhesive activity and that the first two domains of N-cadherin form the "minimal essential unit" to mediate cell adhesion...... domains of N-cadherin have distinct roles in cell adhesion, i.e. the first two domains are responsible for homophilic adhesion activity, and the other domains promote adhesion efficiency most likely by positioning essential domains relatively far out from the cell surface....

E-cadherin expression in primary carcinomas of the breast and its distant metastases

International Nuclear Information System (INIS)

Kowalski, Paul J; Rubin, Mark A; Kleer, Celina G

2003-01-01

Aberrant expression of E-cadherin has been associated with the development of metastases in patients with breast cancer. Even though the expression of E-cadherin has been studied in primary breast tumors, little is known about its expression at the distant metastatic sites. We investigate the relationship between E-cadherin expression in primary breast carcinoma and their distant, non-nodal metastases. Immunohistochemical analysis of E-cadherin was performed in tissues from 30 patients with primary invasive breast carcinoma and their distant metastases. E-cadherin expression was evaluated as normal or aberrant (decreased when compared with normal internal positive controls, or absent). Twenty-two (73%) invasive carcinomas were ductal, and eight (27%) were lobular. Of the primary invasive ductal carcinomas, 55% (12/22) had normal E-cadherin expression and 45% (10/22) had aberrant expression. All of the metastases expressed E-cadherin with the same intensity as (12 tumors) or with stronger intensity than (10 tumors) the corresponding primaries. Of the invasive lobular carcinomas, one of eight (12%) primary carcinomas and none of the metastases expressed E-cadherin in the cell membranes, but they accumulated the protein in the cytoplasm. Aberrant E-cadherin expression is frequent in invasive ductal carcinomas that progress to develop distant metastases. Distant metastases consistently express E-cadherin, often more strongly than the primary tumor. Invasive lobular carcinomas have a different pattern of E-cadherin expression, suggesting a different role for E-cadherin in this form of breast carcinoma

Cell surface N-glycans influence the level of functional E-cadherin at the cell–cell border

Directory of Open Access Journals (Sweden)

M. Kristen Hall

2014-01-01

Full Text Available E-cadherin is crucial for adhesion of cells to each other and thereby development and maintenance of tissue. While it is has been established that N-glycans inside the cell impact the level of E-cadherin at the cell surface of epithelial-derived cells, it is unclear whether N-glycans outside the cell control the clustering of E-cadherin at the cell–cell border. Here, we demonstrate reduction of N-glycans at the cell surface weakened the recruitment and retention of E-cadherin at the cell–cell border, and consequently reduced the strength of cell–cell interactions. We conclude that N-glycans at the cell surface are tightly linked to the placement of E-cadherin at the cell–cell border and thereby control E-cadherin mediated cell–cell adhesion.

Cadherin-11 controls otolith assembly: evidence for extracellular cadherin activity

Science.gov (United States)

Clendenon, Sherry G.; Shah, Bijal; Miller, Caroline A; Schmeisser, Glen; Walter, Amanda; Gattone, Vincent H.; Barald, Kate F.; Liu, Qin; Marrs, James A.

2009-01-01

Cadherin-11/Cdh11 is expressed through early development and strongly during inner ear development (otic placode and vesicle). Here we show that antisense knockdown of Cdh11 during early zebrafish development interferes with otolith formation. Immunofluorescence labeling showed that Cdh11 expression was concentrated on and within the otolith. Cdh11 was faintly detected at the lateral surface (sites of cell-cell contact) of otic epithelial cells and in the cytoplasm. Strongly labeled Cdh11 containing puncta were detected within the otolymph (the fluid within the otic vesicle) and associated with the otolith surface. BODIPY-ceramine labeled vesicular structures detected in the otolymph were larger and more numerous in Cdh11 knockdown embryos. We present evidence supporting a working model that vesicular structures containing Cdh11 (perhaps containing biomineralization components) are exported from the otic epithelium into the otolymph, adhere to one another and to the surface of the growing otolith, facilitating otolith growth. PMID:19582870

The function of 7D-cadherins: a mathematical model predicts physiological importance for water transport through simple epithelia

Directory of Open Access Journals (Sweden)

Walcher Sebastian

2011-06-01

Full Text Available Abstract Background 7D-cadherins like LI-cadherin are cell adhesion molecules and represent exceptional members of the cadherin superfamily. Although LI-cadherin was shown to act as a functional Ca2+-dependent adhesion molecule, linking neighboring cells together, and to be dysregulated in a variety of diseases, the physiological role is still enigmatic. Interestingly 7D-cadherins occur only in the lateral plasma membranes of cells from epithelia of water transporting tissues like the gut, the liver or the kidney. Furthermore LI-cadherin was shown to exhibit a highly cooperative Ca2+-dependency of the binding activity. Thus it is tempting to assume that LI-cadherin regulates the water transport through the epithelium in a passive fashion by changing its binding activity in dependence on the extracellular Ca2+. Results We developed a simple mathematical model describing the epithelial lining of a lumen with a content of variable osmolarity covering an interstitium of constant osmolarity. The width of the lateral intercellular cleft was found to influence the water transport significantly. In the case of hypertonic luminal content a narrow cleft is necessary to further increase concentration of the luminal content. If the cleft is too wide, the water flux will change direction and water is transported into the lumen. Electron microscopic images show that in fact areas of the gut can be found where the lateral intercellular cleft is narrow throughout the lateral cell border whereas in other areas the lateral intercellular cleft is widened. Conclusions Our simple model clearly predicts that changes of the width of the lateral intercellular cleft can regulate the direction and efficiency of water transport through a simple epithelium. In a narrow cleft the cells can increase the concentration of osmotic active substances easily by active transport whereas if the cleft is wide, friction is reduced but the cells can hardly build up high osmotic

SMAD4 regulates cell motility through transcription of N-cadherin in human pancreatic ductal epithelium.

Directory of Open Access Journals (Sweden)

Ya'an Kang

Full Text Available Expression of the cellular adhesion protein N-cadherin is a critical event during epithelial-mesenchymal transition (EMT. The SMAD4 protein has been identified as a mediator of transforming growth factor-β (TGF-β superfamily signaling, which regulates EMT, but the mechanisms linking TGF-β signaling to N-cadherin expression remain unclear. When the TGF-β pathway is activated, SMAD proteins, including the common mediator SMAD4, are subsequently translocated into the nucleus, where they influence gene transcription via SMAD binding elements (SBEs. Here we describe a mechanism for control of CDH2, the gene encoding N-cadherin, through the canonical TGFβ-SMAD4 pathway. We first identified four previously undescribed SBEs within the CDH2 promoter. Using telomerase immortalized human pancreatic ductal epithelium, we found that TGF-β stimulation prompted specific SMAD4 binding to all four SBEs. Luciferase reporter and SMAD4-knockdown experiments demonstrated that specific SMAD4 binding to the SBE located at -3790 bp to -3795 bp within the promoter region of CDH2 was necessary for TGF-β-stimulated transcription. Expression of N-cadherin on the surface of epithelial cells facilitates motility and invasion, and we demonstrated that knockdown of SMAD4 causes decreased N-cadherin expression, which results in diminished migration and invasion of human pancreatic ductal epithelial cells. Similar reduction of cell motility was produced after CDH2 knockdown. Together, these findings suggest that SMAD4 is critical for the TGF-β-driven upregulation of N-cadherin and the resultant invasive phenotype of human pancreatic ductal epithelial cells during EMT.

Cadherin 2/4 signaling via PTP1B and catenins is crucial for nucleokinesis during radial neuronal migration in the neocortex.

Science.gov (United States)

Martinez-Garay, Isabel; Gil-Sanz, Cristina; Franco, Santos J; Espinosa, Ana; Molnár, Zoltán; Mueller, Ulrich

2016-06-15

Cadherins are crucial for the radial migration of excitatory projection neurons into the developing neocortical wall. However, the specific cadherins and the signaling pathways that regulate radial migration are not well understood. Here, we show that cadherin 2 (CDH2) and CDH4 cooperate to regulate radial migration in mouse brain via the protein tyrosine phosphatase 1B (PTP1B) and α- and β-catenins. Surprisingly, perturbation of cadherin-mediated signaling does not affect the formation and extension of leading processes of migrating neocortical neurons. Instead, movement of the cell body and nucleus (nucleokinesis) is disrupted. This defect is partially rescued by overexpression of LIS1, a microtubule-associated protein that has previously been shown to regulate nucleokinesis. Taken together, our findings indicate that cadherin-mediated signaling to the cytoskeleton is crucial for nucleokinesis of neocortical projection neurons during their radial migration. © 2016. Published by The Company of Biologists Ltd.

Structure of a force-conveying cadherin bond essential for inner-ear mechanotransduction.

Science.gov (United States)

Sotomayor, Marcos; Weihofen, Wilhelm A; Gaudet, Rachelle; Corey, David P

2012-12-06

Hearing and balance use hair cells in the inner ear to transform mechanical stimuli into electrical signals. Mechanical force from sound waves or head movements is conveyed to hair-cell transduction channels by tip links, fine filaments formed by two atypical cadherins known as protocadherin 15 and cadherin 23 (refs 4, 5). These two proteins are involved in inherited deafness and feature long extracellular domains that interact tip-to-tip in a Ca(2+)-dependent manner. However, the molecular architecture of this complex is unknown. Here we combine crystallography, molecular dynamics simulations and binding experiments to characterize the protocadherin 15-cadherin 23 bond. We find a unique cadherin interaction mechanism, in which the two most amino-terminal cadherin repeats (extracellular cadherin repeats 1 and 2) of each protein interact to form an overlapped, antiparallel heterodimer. Simulations predict that this tip-link bond is mechanically strong enough to resist forces in hair cells. In addition, the complex is shown to become unstable in response to Ca(2+) removal owing to increased flexure of Ca(2+)-free cadherin repeats. Finally, we use structures and biochemical measurements to study the molecular mechanisms by which deafness mutations disrupt tip-link function. Overall, our results shed light on the molecular mechanics of hair-cell sensory transduction and on new interaction mechanisms for cadherins, a large protein family implicated in tissue and organ morphogenesis, neural connectivity and cancer.

Replacement of E-cadherin by N-cadherin in the mammary gland leads to fibrocystic changes and tumor formation.

Science.gov (United States)

Kotb, Ahmed M; Hierholzer, Andreas; Kemler, Rolf

2011-10-26

E-cadherin (E-cad; cadherin 1) and N-cadherin (N-cad; cadherin 2) are the most prominent members of the cadherin family of cell adhesion molecules. Although they share many structural and functional features, they are expressed in an almost mutually exclusive manner in vivo. To explore functional differences between the two cadherins in vivo, we recently generated a knock-in line in which N-cad is expressed from the E-cad locus. In combination with a conditional gene inactivation approach, we expressed N-cad in the absence of E-cad (referred to as Ncadk.i.) in alveolar epithelial cells of the mammary gland starting in late pregnancy. We found that the sole presence of N-cad induces constitutively active fibroblast growth factor (Fgf) signaling and a precocious involution resulting in massive apoptosis of alveolar cells. To block apoptosis, we conditionally deleted one allele of p53 in Ncadk.i. mice and observed a temporal rescue of alveolar morphology and function. However, an accumulation of fibrotic tissue and cysts with increasing age and lactation cycles was observed. This phenotype closely resembled fibrocystic mastopathy (FM), a common disorder in humans, which is thought to precede breast cancer. Concordantly, 55% of Ncadk.i. mice harboring a heterozygous p53 deletion developed malignant and invasive tumors. Our results demonstrate a possible role for N-cad in the formation of fibrosis and cysts in the mammary gland. Moreover, we show that these lesions precede the development of malignant tumors. Thus, we provide a new mouse model to investigate the molecular mechanisms of fibrocystic mastopathy and the transition from benign to malignant tumors.

E-cadherin homophilic ligation inhibits cell growth and epidermal growth factor receptor signaling independently of other cell interactions

DEFF Research Database (Denmark)

Perrais, Michaël; Chen, Xiao; Perez-Moreno, Mirna

2007-01-01

growth inhibitory signals. To address this question, we have selectively formed E-cadherin homophilic bonds at the cell surface of isolated epithelial cells by using functionally active recombinant E-cadherin protein attached to microspheres. We find that E-cadherin ligation alone reduces the frequency...... of cells entering the S phase, demonstrating that E-cadherin ligation directly transduces growth inhibitory signals. E-cadherin binding to beta-catenin is required for cell growth inhibition, but beta-catenin/T-cell factor transcriptional activity is not involved in growth inhibition resulting from...... homophilic binding. Neither E-cadherin binding to p120-catenin nor beta-catenin binding to alpha-catenin, and thereby the actin cytoskeleton, is required for growth inhibition. E-cadherin ligation also inhibits epidermal growth factor (EGF) receptor-mediated growth signaling by a beta...

Evolutionary origin of type IV classical cadherins in arthropods.

Science.gov (United States)

Sasaki, Mizuki; Akiyama-Oda, Yasuko; Oda, Hiroki

2017-06-17

Classical cadherins are a metazoan-specific family of homophilic cell-cell adhesion molecules that regulate morphogenesis. Type I and type IV cadherins in this family function at adherens junctions in the major epithelial tissues of vertebrates and insects, respectively, but they have distinct, relatively simple domain organizations that are thought to have evolved by independent reductive changes from an ancestral type III cadherin, which is larger than derived paralogs and has a complicated domain organization. Although both type III and type IV cadherins have been identified in hexapods and branchiopods, the process by which the type IV cadherin evolved is still largely unclear. Through an analysis of arthropod genome sequences, we found that the only classical cadherin encoded in chelicerate genomes was the type III cadherin and that the two type III cadherin genes found in the spider Parasteatoda tepidariorum genome exhibited a complex yet ancestral exon-intron organization in arthropods. Genomic and transcriptomic data from branchiopod, copepod, isopod, amphipod, and decapod crustaceans led us to redefine the type IV cadherin category, which we separated into type IVa and type IVb, which displayed a similar domain organization, except type IVb cadherins have a larger number of extracellular cadherin (EC) domains than do type IVa cadherins (nine versus seven). We also showed that type IVa cadherin genes occurred in the hexapod, branchiopod, and copepod genomes whereas only type IVb cadherin genes were present in malacostracans. Furthermore, comparative characterization of the type IVb cadherins suggested that the presence of two extra EC domains in their N-terminal regions represented primitive characteristics. In addition, we identified an evolutionary loss of two highly conserved cysteine residues among the type IVa cadherins of insects. We provide a genomic perspective of the evolution of classical cadherins among bilaterians, with a focus on the Arthropoda

Correlation between E-cadherin-regulated cell adhesion and human osteosarcoma MG-63 cell anoikis.

Science.gov (United States)

Lin, Ding-Sheng; Cai, Le-Yi; Ding, Jian; Gao, Wei-Yang

2014-01-01

The aim of this study was to investigate the relationship between cell adhesion and anoikis evasion among human osteosarcoma cells (MG-63), and to further study the molecular mechanisms. Human osteosarcoma cells (MG-63) were assessed for apoptosis, and caspase-3, E-cadherin and β-catenin expression in EDTA and control non-EDTA groups. MG-63 cells were predominantly aggregated when in suspension, and the suspended cells were more dispersed in the EDTA group. Following culture in suspension for 24 h, 48 h, or 72 h, the rates of apoptosis were 34.88%±3.64%, 59.3%±7.22% and 78.5%±5.21% in the experimental group and 7.34%±2.13%, 14.7%±3.69%, and 21.4%±3.60% in the control group, respectively. Caspase-3 expression progressively increased and E-cadherin and β-catenin were decreased in the experimental group, whereas there was no change in the control group. MG-63 cells could avoid anoikis through cell adhesion, and E-cadherin might play a role in this process.

e-Cadherin in 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine-Induced Parkinson Disease

Directory of Open Access Journals (Sweden)

Samuela Cataldi

2016-01-01

Full Text Available Today a large number of studies are focused on clarifying the complexity and diversity of the pathogenetic mechanisms inducing Parkinson disease. We used 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, a neurotoxin that induces Parkinson disease, to evaluate the change of midbrain structure and the behavior of the anti-inflammatory factor e-cadherin, interleukin-6, tyrosine hydroxylase, phosphatase and tensin homolog, and caveolin-1. The results showed a strong expression of e-cadherin, variation of length and thickness of the heavy neurofilaments, increase of interleukin-6, and reduction of tyrosine hydroxylase known to be expression of dopamine cell loss, reduction of phosphatase and tensin homolog described to impair responses to dopamine, and reduction of caveolin-1 known to be expression of epithelial-mesenchymal transition and fibrosis. The possibility that the overexpression of the e-cadherin might be implicated in the anti-inflammatory reaction to MPTP treatment by influencing the behavior of the other analyzed molecules is discussed.

The transcription factor snail controls epithelial-mesenchymal transitions by repressing E-cadherin expression

DEFF Research Database (Denmark)

Cano, A; Pérez-Moreno, M A; Rodrigo, I

2000-01-01

The Snail family of transcription factors has previously been implicated in the differentiation of epithelial cells into mesenchymal cells (epithelial-mesenchymal transitions) during embryonic development. Epithelial-mesenchymal transitions are also determinants of the progression of carcinomas......, occurring concomitantly with the cellular acquisition of migratory properties following downregulation of expression of the adhesion protein E-cadherin. Here we show that mouse Snail is a strong repressor of transcription of the E-cadherin gene. Epithelial cells that ectopically express Snail adopt...

The expression of VE-cadherin in breast cancer cells modulates cell dynamics as a function of tumor differentiation and promotes tumor-endothelial cell interactions.

Science.gov (United States)

Rezaei, Maryam; Cao, Jiahui; Friedrich, Katrin; Kemper, Björn; Brendel, Oliver; Grosser, Marianne; Adrian, Manuela; Baretton, Gustavo; Breier, Georg; Schnittler, Hans-Joachim

2018-01-01

The cadherin switch has profound consequences on cancer invasion and metastasis. The endothelial-specific vascular endothelial cadherin (VE-cadherin) has been demonstrated in diverse cancer types including breast cancer and is supposed to modulate tumor progression and metastasis, but underlying mechanisms need to be better understood. First, we evaluated VE-cadherin expression by tissue microarray in 392 cases of breast cancer tumors and found a diverse expression and distribution of VE-cadherin. Experimental expression of fluorescence-tagged VE-cadherin (VE-EGFP) in undifferentiated, fibroblastoid and E-cadherin-negative MDA-231 (MDA-VE-EGFP) as well as in differentiated E-cadherin-positive MCF-7 human breast cancer cell lines (MCF-VE-EGFP), respectively, displayed differentiation-dependent functional differences. VE-EGFP expression reversed the fibroblastoid MDA-231 cells to an epithelial-like phenotype accompanied by increased β-catenin expression, actin and vimentin remodeling, increased cell spreading and barrier function and a reduced migration ability due to formation of VE-cadherin-mediated cell junctions. The effects were largely absent in both MDA-VE-EGFP and in control MCF-EGFP cell lines. However, MCF-7 cells displayed a VE-cadherin-independent planar cell polarity and directed cell migration that both developed in MDA-231 only after VE-EGFP expression. Furthermore, VE-cadherin expression had no effect on tumor cell proliferation in monocultures while co-culturing with endothelial cells enhanced tumor cell proliferation due to integration of the tumor cells into monolayer where they form VE-cadherin-mediated cell contacts with the endothelium. We propose an interactive VE-cadherin-based crosstalk that might activate proliferation-promoting signals. Together, our study shows a VE-cadherin-mediated cell dynamics and an endothelial-dependent proliferation in a differentiation-dependent manner.

Unconventional Cadherin Localization in Honey Bee Gonads Revealed Through Domain-Specific Apis mellifera E- and N-Cadherin Antibodies Indicates Alternative Functions

Directory of Open Access Journals (Sweden)

Klaus Hartfelder

2012-11-01

Full Text Available As key factors in intercellular adhesion processes, cadherins play important roles in a plethora of developmental processes, including gametogenesis. In a previous study on cadherin localization in the gonads of honey bees, performed with heterologous pan-cadherin antibodies, we detected these proteins as (i associated with cell membranes, (ii as homogeneously distributed throughout the cytoplasm, and (iii as nuclear foci in both somatic and germline cells, raising the possibility of alternative functions. To further investigate such unusual intracellular cadherin localization we produced specific antibodies against the N- and C-terminal domains of honey bee N- and E-cadherin. A 160 kDa protein was recognized by the E-cadherin antibodies as well as one of approximately 300 kDa from those raised against N-cadherin. In gonad preparations, both proteins were detected as dispersed throughout the cytoplasm and as nuclear foci in both germline and somatic cells of queen and worker ovarioles, as well as in the testioles of drones. This leads us to infer that cadherins may indeed be involved in certain signaling pathways and/or transcriptional regulation during gametogenesis. In late oogenesis stages, immunolabeling for both proteins was observed at the cell cortex, in conformity with a role in cell adhesion. In testioles, E-cadherin was seen in co-localization with fusomes, indicating a possible role in cyst organization. Taken together, the distribution of N- and E-cadherins in honey bee gonads is suggestive of alternative roles for cadherins in gametogenesis of both sexes.

Defects in ultrasonic vocalization of cadherin-6 knockout mice.

Directory of Open Access Journals (Sweden)

Ryoko Nakagawa

Full Text Available BACKGROUND: Although some molecules have been identified as responsible for human language disorders, there is still little information about what molecular mechanisms establish the faculty of human language. Since mice, like songbirds, produce complex ultrasonic vocalizations for intraspecific communication in several social contexts, they can be good mammalian models for studying the molecular basis of human language. Having found that cadherins are involved in the vocal development of the Bengalese finch, a songbird, we expected cadherins to also be involved in mouse vocalizations. METHODOLOGY/PRINCIPAL FINDINGS: To examine whether similar molecular mechanisms underlie the vocalizations of songbirds and mammals, we categorized behavioral deficits including vocalization in cadherin-6 knockout mice. Comparing the ultrasonic vocalizations of cadherin-6 knockout mice with those of wild-type controls, we found that the peak frequency and variations of syllables were differed between the mutant and wild-type mice in both pup-isolation and adult-courtship contexts. Vocalizations during male-male aggression behavior, in contrast, did not differ between mutant and wild-type mice. Open-field tests revealed differences in locomotors activity in both heterozygote and homozygote animals and no difference in anxiety behavior. CONCLUSIONS/SIGNIFICANCE: Our results suggest that cadherin-6 plays essential roles in locomotor activity and ultrasonic vocalization. These findings also support the idea that different species share some of the molecular mechanisms underlying vocal behavior.

The E-cadherin/catenin complex: an important gatekeeper in breast cancer tumorigenesis and malignant progression

International Nuclear Information System (INIS)

Berx, Geert; Roy, Frans Van

2001-01-01

E-cadherin is a cell–cell adhesion protein fulfilling a prominent role in epithelial differentiation. Data from model systems suggest that E-cadherin is a potent invasion/tumor suppressor of breast cancer. Consistent with this role in breast cancer progression, partial or complete loss of E-cadherin expression has been found to correlate with poor prognosis in breast cancer patients. The E-cadherin gene (CDH1) is located on human chromosome 16q22.1, a region frequently affected with loss of heterozygosity in sporadic breast cancer. Invasive lobular breast carcinomas, which are typically completely E-cadherin-negative, often show inactivating mutations in combination with loss of heterozygosity of the wild-type CDH1 allele. Mutations were found at early noninvasive stages, thus associating E-cadherin mutations with loss of cell growth control and defining CDH1 as the tumor suppressor for the lobular breast cancer subtype. Ductal breast cancers in general show heterogeneous loss of E-cadherin expression, associated with epigenetic transcriptional downregulation. It is proposed that the microenvironment at the invasive front is transiently downregulating E-cadherin transcription. This can be associated with induction of nonepithelial cadherins

Cadherin genes and evolutionary novelties in the octopus.

Science.gov (United States)

Wang, Z Yan; Ragsdale, Clifton W

2017-09-01

All animals with large brains must have molecular mechanisms to regulate neuronal process outgrowth and prevent neurite self-entanglement. In vertebrates, two major gene families implicated in these mechanisms are the clustered protocadherins and the atypical cadherins. However, the molecular mechanisms utilized in complex invertebrate brains, such as those of the cephalopods, remain largely unknown. Recently, we identified protocadherins and atypical cadherins in the octopus. The octopus protocadherin expansion shares features with the mammalian clustered protocadherins, including enrichment in neural tissues, clustered head-to-tail orientations in the genome, and a large first exon encoding all cadherin domains. Other octopus cadherins, including a newly-identified cadherin with 77 extracellular cadherin domains, are elevated in the suckers, a striking cephalopod novelty. Future study of these octopus genes may yield insights into the general functions of protocadherins in neural wiring and cadherin-related proteins in complex morphogenesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Loss of E-Cadherin-Dependent Cell-Cell Adhesion and the Development and Progression of Cancer.

Science.gov (United States)

Bruner, Heather C; Derksen, Patrick W B

2018-03-01

Classical cadherins are the key molecules that control cell-cell adhesion. Notwithstanding this function, it is also clear that classical cadherins are more than just the "glue" that keeps the cells together. Cadherins are essential regulators of tissue homeostasis that govern multiple facets of cellular function and development, by transducing adhesive signals to a complex network of signaling effectors and transcriptional programs. In cancer, cadherins are often inactivated or functionally inhibited, resulting in disease development and/or progression. This review focuses on E-cadherin and its causal role in the development and progression of breast and gastric cancer. We provide a summary of the biochemical consequences and consider the conceptual impact of early (mutational) E-cadherin loss in cancer. We advocate that carcinomas driven by E-cadherin loss should be considered "actin-diseases," caused by the specific disruption of the E-cadherin-actin connection and a subsequent dependence on sustained actomyosin contraction for tumor progression. Based on the available data from mouse and human studies we discuss opportunities for targeted clinical intervention. Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.

Prognostic value of E-cadherin, beta-catenin, CD44v6, and HER2/neu in metastatic cutaneous adenocarcinoma.

Science.gov (United States)

Pozdnyakova, Olga; Hoang, Mai M P; Dresser, Karen A; Mahalingam, Meera

2009-08-01

Our recent experience with a patient developing cutaneous metastases within 3 months of diagnosis of esophageal adenocarcinoma suggests that altered expression of the cellular adhesion molecules, E-cadherin and CD44v6, may have had a role to play in the rapid onset of metastases. To corroborate these findings, we designed a cross-sectional study to investigate the expression of select molecules involved in the metastatic cascade. E-cadherin, beta-catenin, CD44v6, and HER2/neu immunohistochemical stains were performed on archival materials of metastatic adenocarcinoma to the skin from 27 patients and the available corresponding primary tumors in 10 patients. The primary sites included breast (n = 10; 37%), gastrointestinal tract (n = 10; 37%), ovary (n = 1; 4%), thyroid (n = 2; 7%), lung (n = 1; 4%), and unknown primary (n = 3; 11%). Expression of all markers was noted with the most significant increases observed in beta-catenin (26 of 27 cases; 96%), followed by CD44v6 (24 of 27 cases; 89%), E-cadherin (22 of 27 cases; 82%), and HER2/neu (11 of 27 cases; 41%). Contrasting expression of these molecules in the primary versus the metastatic tumors, enhanced expression of CD44v6 was observed in the cutaneous metastases relative to the primary in 6 of 10 (60%) cases. Of interest, 2 of these 6 cases (33%) also showed reduction in E-cadherin--a member of the cadherin family functioning as an invasion suppressor molecule. These findings reinforce the complexities of the metastatic cascade and imply that the variation in adhesive properties of tumor cells is, perhaps, a consequence of the difference in density of the molecules mediating this process.

EXPRESSION OF SURVIVIN AND E-CADHERIN IN BREAST CANCER

Institute of Scientific and Technical Information of China (English)

TIAN Xiao-feng; LIU Ji-hong; WANG Li-fen; FENG XIAO-Mei; YAO Ji-hong

2005-01-01

Objective: Survivin is a member of the inhibitor of apoptosis (IAP) family, and is involved in the regulation of cell division. E-cadherin functionally belongs to transmembrane glycoproteins family, it is responsible for intercellular junction mechanism that is crucial for the mutual association of vertebrate cells. These genes are thought to be associated with cancer aggression. This study was to investigate the relationship between surviving gene, E-cadherin expression and invasion clinicopathological features of breast cancer. Methods: The expression of surviving gene and E-cadherin were detected by SP immunohistochemical technique in tissues of 66 breast cancer, 20 breast fibroadenoma and 20 adjacent breast tissue. Results: The positive rate of surviving gene expression in breast cancer was 42.2%, significantly higher (P=0.025) than those in breast fibroadenoma (35.0%), and adjacent breast tissue (10.0%). The positive rate of E-cadherin in the groups of adjacent breast tissue, breast fibroadenoma and breast cancer were 100%, 100% and 42.4%, there was significant difference between the group of benign and malignant tumor (P=0.005). The positive rate of surviving in breast cancer with local lymph node metastasis was significant higher than that in breast cancer without lymph node metastasis (P=0.01), and E-cadherin in breast cancer with local lymph node metastasis was significant lower than that without lymph node metastasis (P=o.o1). There was no significant difference among the groups of pathological types and TNM stages in the expression of surviving (P=0.966 & P=0.856), but there was significant difference in the expression of E-cadherin among these groups (P=0.01 & P=0.023). Conclusion: The loss or decrease of E-cadherin expression may promote the exfoliation of cancerous cells from original tissues, and surviving gene may promote the viability of the exfoliated cancer cells and the formation of new metastasis focus. These 2 factors cooperate with each other

Effects of CD44 and E-cadherin overexpression on the proliferation, adhesion and invasion of ovarian cancer cells.

Science.gov (United States)

Mao, Meiya; Zheng, Xiaojiao; Jin, Bohong; Zhang, Fubin; Zhu, Linyan; Cui, Lining

2017-12-01

CD44 is a prognostic indicator of shorter survival time in ovarian cancer. E-cadherin fragmentation promotes the progression of ovarian cancer. However, the effects of CD44 and E-cadherin overexpression on ovarian cancer cells have remained elusive. The present study aimed to investigate the effects of overexpression of CD44 and E-cadherin on cell proliferation, adhesion and invasion of SKOV-3 and OVCAR-3 ovarian cancer cells. Overexpression of CD44 and E-cadherin was achieved by transfecting SKOV-3 and OVCAR-3 cells with viruses carrying the CD44 or E-cadherin gene, respectively. Expression of CD44 and E-cadherin was detected by western blot analysis. The proliferation of SKOV-3 and OVCAR-3 cells was measured by a Cell Counting Kit-8 at 0, 24 and 48 h after viral transfection. The adhesion ability of SKOV-3 and OVCAR-3 cells to the endothelial layer was detected. A Transwell invasion assay was utilized to assess the invasion ability of the cells. Overexpression of CD44 and E-cadherin in SKOV-3 and OVCAR-3 cells was confirmed by western blot. Compared with the blank or negative control groups, the CD44 overexpression groups of SKOV-3 and OVCAR-3 cells exhibited an increased cell proliferation rate at 24 and 48 h, whereas overexpression of E-cadherin did not alter the proliferation of these cells. Furthermore, compared with the blank and negative control groups, the cell adhesion and invasion ability in the CD44 overexpression groups of SKOV-3 and OVCAR-3 cells was markedly higher. There were no significant differences in adhesion ability between the E-cadherin overexpression group and the blank/negative control group. Of note, overexpression of E-cadherin decreased the invasive ability of SKOV-3 and OVCAR-3 cells. In conclusion, Overexpression of CD44 increased the proliferation, adhesion and invasion of ovarian cancer cells, while overexpression of E-cadherin decreased the invasion of ovarian cancer cells.

Restricted expression of classic cadherins in the spinal cord of the chicken embryo

Directory of Open Access Journals (Sweden)

Juntang eLin

2014-03-01

Full Text Available Classic cadherins belong to the family of cadherin genes and play important roles in neurogenesis, neuron migration and axon growth. In the present study, we compared the expression patterns of 10 classic cadherins (Cdh2, Cdh4, Cdh6, Cdh7, Cdh8, Cdh9, Cdh11, Cdh12, Cdh18 and Cdh20 in the developing chicken spinal cord by in situ hybridization. Our results indicate that each of the investigated cadherins exhibits a spatially restricted and temporally regulated pattern of expression. At early developmental stages (E2.5-E3, Cdh2 is expressed throughout the neuroepithelial layer. Cdh6 is strongly positive in the roof plate and later also in the floor plate. Cdh7, Cdh11, Cdh12 and Cdh20 are expressed in restricted regions of the basal plate of the spinal cord. At intermediate stages of development (E4-E10, specific expression profiles are observed for all investigated cadherins in the differentiating mantle layer along the dorsoventral, mediolateral and rostrocaudal dimensions. Expression profiles are especially diverse for Cdh2, Cdh4, Cdh8, Cdh11 and Cdh20 in the dorsal horn, while different pools of motor neurons exhibit signal for Cdh6, Cdh7, Cdh8, Cdh9, Cdh12 and Cdh20 in the ventral horn. Interestingly, subpopulations of cells in the dorsal root ganglion express combinations of different cadherins. In the surrounding tissues, such as the boundary cap cells and the notochord, the cadherins are also expressed differentially. The highly regulated spatiotemporal expression patterns of the classic cadherins indicate that these genes potentially play multiple and diverse roles during the development of the spinal cord and its surrounding tissues.

Aberrant E-cadherin staining patterns in invasive mammary carcinoma

Directory of Open Access Journals (Sweden)

Brogi Edi

2005-11-01

Full Text Available Abstract Background E-cadherin, a cell surface protein involved in cell adhesion, is present in normal breast epithelium, benign breast lesions, and in breast carcinoma. Alterations in the gene CDH1 on chromosome 16q22 are associated with changes in E-cadherin protein expression and function. Inactivation of E-cadherin in lobular carcinomas and certain diffuse gastric carcinomas may play a role in the dispersed, discohesive "single cell" growth patterns seen in these tumors. The molecular "signature" of mammary lobular carcinomas is the loss of E-cadherin protein expression as evidenced by immunohistochemistry, whereas ductal carcinomas are typically E-cadherin positive. Patients and methods We report on E-cadherin immunostaining patterns in five cases of invasive mammary carcinoma Results These were five exceptional instances in which the E-cadherin immunophenotype did not correspond to the apparent histologic classification of the lesion. These cases which are exceedingly rare in our experience are the subject of this report. Conclusion Findings such as those illustrated in this study occur in virtually all biologic phenomena and they do not invalidate the very high degree of correlation between the expression of E-cadherin and the classification of breast carcinomas as ductal or lobular type on the basis of conventional histologic criteria.

PIST regulates the intracellular trafficking and plasma membrane expression of Cadherin 23

Directory of Open Access Journals (Sweden)

Oshima Kazuo

2010-10-01

Full Text Available Abstract Background The atypical cadherin protein cadherin 23 (CDH23 is crucial for proper function of retinal photoreceptors and inner ear hair cells. As we obtain more and more information about the specific roles of cadherin 23 in photoreceptors and hair cells, the regulatory mechanisms responsible for the transport of this protein to the plasma membrane are largely unknown. Results PIST, a Golgi-associated, PDZ domain-containing protein, interacted with cadherin 23 via the PDZ domain of PIST and the C-terminal PDZ domain-binding interface (PBI of cadherin 23. By binding to cadherin 23, PIST retained cadherin 23 in the trans-Golgi network of cultured cells. The retention was released when either of the two known cadherin 23-binding proteins MAGI-1 and harmonin was co-expressed. Similar to MAGI-1 and harmonin, PIST was detected in mouse inner ear sensory hair cells. Conclusions PIST binds cadherin 23 via its PDZ domain and retains cadherin 23 in trans-Golgi network. MAGI-1 and harmonin can compete with PIST for binding cadherin 23 and release cadherin 23 from PIST's retention. Our finding suggests that PIST, MAGI-1 and harmonin collaborate in intracellular trafficking of cadherin 23 and regulate the plasma membrane expression of cadherin 23.

Als3 is a Candida albicans invasin that binds to cadherins and induces endocytosis by host cells.

Directory of Open Access Journals (Sweden)

Quynh T Phan

2007-03-01

Full Text Available Candida albicans is the most common cause of hematogenously disseminated and oropharyngeal candidiasis. Both of these diseases are characterized by fungal invasion of host cells. Previously, we have found that C. albicans hyphae invade endothelial cells and oral epithelial cells in vitro by inducing their own endocytosis. Therefore, we set out to identify the fungal surface protein and host cell receptors that mediate this process. We found that the C. albicans Als3 is required for the organism to be endocytosed by human umbilical vein endothelial cells and two different human oral epithelial lines. Affinity purification experiments with wild-type and an als3delta/als3delta mutant strain of C. albicans demonstrated that Als3 was required for C. albicans to bind to multiple host cell surface proteins, including N-cadherin on endothelial cells and E-cadherin on oral epithelial cells. Furthermore, latex beads coated with the recombinant N-terminal portion of Als3 were endocytosed by Chinese hamster ovary cells expressing human N-cadherin or E-cadherin, whereas control beads coated with bovine serum albumin were not. Molecular modeling of the interactions of the N-terminal region of Als3 with the ectodomains of N-cadherin and E-cadherin indicated that the binding parameters of Als3 to either cadherin are similar to those of cadherin-cadherin binding. Therefore, Als3 is a fungal invasin that mimics host cell cadherins and induces endocytosis by binding to N-cadherin on endothelial cells and E-cadherin on oral epithelial cells. These results uncover the first known fungal invasin and provide evidence that C. albicans Als3 is a molecular mimic of human cadherins.

VE-cadherin cleavage by LasB protease from Pseudomonas aeruginosa facilitates type III secretion system toxicity in endothelial cells.

Directory of Open Access Journals (Sweden)

Guillaume Golovkine

2014-03-01

Full Text Available Infection of the vascular system by Pseudomonas aeruginosa (Pa occurs during bacterial dissemination in the body or in blood-borne infections. Type 3 secretion system (T3SS toxins from Pa induce a massive retraction when injected into endothelial cells. Here, we addressed the role of type 2 secretion system (T2SS effectors in this process. Mutants with an inactive T2SS were much less effective than wild-type strains at inducing cell retraction. Furthermore, secretomes from wild-types were sufficient to trigger cell-cell junction opening when applied to cells, while T2SS-inactivated mutants had minimal activity. Intoxication was associated with decreased levels of vascular endothelial (VE-cadherin, a homophilic adhesive protein located at endothelial cell-cell junctions. During the process, the protein was cleaved in the middle of its extracellular domain (positions 335 and 349. VE-cadherin attrition was T3SS-independent but T2SS-dependent. Interestingly, the epithelial (E-cadherin was unaffected by T2SS effectors, indicating that this mechanism is specific to endothelial cells. We showed that one of the T2SS effectors, the protease LasB, directly affected VE-cadherin proteolysis, hence promoting cell-cell junction disruption. Furthermore, mouse infection with Pa to induce acute pneumonia lead to significant decreases in lung VE-cadherin levels, whereas the decrease was minimal with T2SS-inactivated or LasB-deleted mutant strains. We conclude that the T2SS plays a pivotal role during Pa infection of the vascular system by breaching the endothelial barrier, and propose a model in which the T2SS and the T3SS cooperate to intoxicate endothelial cells.

Perturbed desmosomal cadherin expression in grainy head-like 1-null mice.

Science.gov (United States)

Wilanowski, Tomasz; Caddy, Jacinta; Ting, Stephen B; Hislop, Nikki R; Cerruti, Loretta; Auden, Alana; Zhao, Lin-Lin; Asquith, Stephen; Ellis, Sarah; Sinclair, Rodney; Cunningham, John M; Jane, Stephen M

2008-03-19

In Drosophila, the grainy head (grh) gene plays a range of key developmental roles through the regulation of members of the cadherin gene family. We now report that mice lacking the grh homologue grainy head-like 1 (Grhl1) exhibit hair and skin phenotypes consistent with a reduction in expression of the genes encoding the desmosomal cadherin, desmoglein 1 (Dsg1). Grhl1-null mice show an initial delay in coat growth, and older mice exhibit hair loss as a result of poor anchoring of the hair shaft in the follicle. The mice also develop palmoplantar keratoderma, analogous to humans with DSG1 mutations. Sequence analysis, DNA binding, and chromatin immunoprecipitation experiments demonstrate that the human and mouse Dsg1 promoters are direct targets of GRHL1. Ultrastructural analysis reveals reduced numbers of abnormal desmosomes in the interfollicular epidermis. These findings establish GRHL1 as an important regulator of the Dsg1 genes in the context of hair anchorage and epidermal differentiation, and suggest that cadherin family genes are key targets of the grainy head-like genes across 700 million years of evolution.

Immunohistochemical Observation of Co-expression of E- and N-cadherins in Rat Organogenesis

International Nuclear Information System (INIS)

Sakamoto, Atsushi; Murata, Kazumoto; Suzuki, Hideto; Yatabe, Megumi; Kikuchi, Motoshi

2008-01-01

Cadherins are a family of transmembrane glycoproteins that mediate cell-to-cell adhesion. Isoforms, including E- and N-cadherin, have been identified and shown to regulate morphogenesis through homophilic binding. In the ontogeny, the expressions of E- and N-cadherin change spatiotemporally, and the changes in cadherin isoforms, called cadherin switching, impact the mechanical adhesion of cells. Furthermore, cadherin functions as a receptor that transfers information from outside to inside cells, and in terms of switching, it affects cell phenotypes. To observe the expression patterns of E- and N-cadherins during embryogenesis and to identify cells that transiently coexpress both cadherins, we employed a recently developed immunohistochemical double staining technique in rat fetuses. At embryonic day 9, embryonic ectodermal cells more dominantly expressed E-cadherin, while mesodermal cells more dominantly expressed N-cadherin. At embryonic day 10, the expression pattern of E-cadherin in the surface ectoderm and endoderm and that of N-cadherin in the neuroectoderm were established. After embryonic day 10, unique co-expression of E- and N-cadherin was observed in primordia, such as the bulbus cordis, otic pit, notochord, and Rathke’s pouch. In the present study, it was possible to visualize the expression patterns of E- and N-cadherin during early fetal development, which enabled us to morphologically clarify cadherin switching

Cell surface clustering of Cadherin adhesion complex induced by antibody coated beads

Institute of Scientific and Technical Information of China (English)

无

2000-01-01

Cadherin receptors mediate cell-cell adhesion, signal transduction and assembly of cytoskeletons. How a single transmembrane molecule Cadherin can be involved in multiple functions through modulating its binding activities with many membrane adhesion molecules and cytoskeletal components is an unanswered question which can be elucidated by clues from bead experiments. Human lung cells expressing N-Cadherin were examined. After co-incubation with anti-N-Cadherin monoclonal antibody coated beads, cell surface clustering of N-Cadherin was induced. Immunofluorescent detection demonstrated that in addition to Cadherin, β-Catenin, α-Catenin, α-Actinin and Actin fluorescence also aggregated respectively at the membrane site of bead attachment. Myosin heavy chain (MHC), another major component of Actin cytoskeleton, did not aggregate at the membrane site of bead attachment. Adhesion unrelated protein Con A and polylysine conjugated beads did not induce the clustering of adhesion molecules. It is indicated that the Cadherin/Catenins/α-Actinin/Actin complex is formed at Cadherin mediated cell adherens junction; occupancy and cell surface clustering of Cadherin is crucial for the formation of Cadherin adhesion protein complexes.

Amino-terminal domain of classic cadherins determines the specificity of the adhesive interactions

DEFF Research Database (Denmark)

Klingelhöfer, Jörg; Troyanovsky, R B; Laur, O Y

2000-01-01

Classic cadherins are transmembrane receptors involved in cell type-specific calcium-dependent intercellular adhesion. The specificity of adhesion is mediated by homophilic interactions between cadherins extending from opposing cell surfaces. In addition, classic cadherins can self-associate form......Classic cadherins are transmembrane receptors involved in cell type-specific calcium-dependent intercellular adhesion. The specificity of adhesion is mediated by homophilic interactions between cadherins extending from opposing cell surfaces. In addition, classic cadherins can self....... To study lateral and adhesive intercadherin interactions, we examined interactions between two classic cadherins, E- and P-cadherins, in epithelial A-431 cells co-producing both proteins. We showed that these cells exhibited heterocomplexes consisting of laterally assembled E- and P....... The specificity of adhesive interaction was localized to the amino-terminal (EC1) domain of both cadherins. Thus, EC1 domain of classic cadherins exposes two determinants responsible for nonspecific lateral and cadherin type-specific adhesive dimerization....

Functional characterization of E- and P-cadherin in invasive breast cancer cells

International Nuclear Information System (INIS)

Sarrió, David; Palacios, José; Hergueta-Redondo, Marta; Gómez-López, Gonzalo; Cano, Amparo; Moreno-Bueno, Gema

2009-01-01

Alterations in the cadherin-catenin adhesion complexes are involved in tumor initiation, progression and metastasis. However, the functional implication of distinct cadherin types in breast cancer biology is still poorly understood. To compare the functional role of E-cadherin and P-cadherin in invasive breast cancer, we stably transfected these molecules into the MDA-MB-231 cell line, and investigated their effects on motility, invasion and gene expression regulation. Expression of either E- and P-cadherin significantly increased cell aggregation and induced a switch from fibroblastic to epithelial morphology. Although expression of these cadherins did not completely reverse the mesenchymal phenotype of MDA-MB-231 cells, both E- and P-cadherin decreased fibroblast-like migration and invasion through extracellular matrix in a similar way. Moreover, microarray gene expression analysis of MDA-MB-231 cells after expression of E- and P-cadherins revealed that these molecules can activate signaling pathways leading to significant changes in gene expression. Although the expression patterns induced by E- and P-cadherin showed more similarities than differences, 40 genes were differentially modified by the expression of either cadherin type. E- and P-cadherin have similar functional consequences on the phenotype and invasive behavior of MDA-MB-231 cells. Moreover, we demonstrate for the first time that these cadherins can induce both common and specific gene expression programs on invasive breast cancer cells. Importantly, these identified genes are potential targets for future studies on the functional consequences of altered cadherin expression in human breast cancer

Functional characterization of E- and P-cadherin in invasive breast cancer cells

Directory of Open Access Journals (Sweden)

Cano Amparo

2009-03-01

Full Text Available Abstract Background Alterations in the cadherin-catenin adhesion complexes are involved in tumor initiation, progression and metastasis. However, the functional implication of distinct cadherin types in breast cancer biology is still poorly understood. Methods To compare the functional role of E-cadherin and P-cadherin in invasive breast cancer, we stably transfected these molecules into the MDA-MB-231 cell line, and investigated their effects on motility, invasion and gene expression regulation. Results Expression of either E- and P-cadherin significantly increased cell aggregation and induced a switch from fibroblastic to epithelial morphology. Although expression of these cadherins did not completely reverse the mesenchymal phenotype of MDA-MB-231 cells, both E- and P-cadherin decreased fibroblast-like migration and invasion through extracellular matrix in a similar way. Moreover, microarray gene expression analysis of MDA-MB-231 cells after expression of E- and P-cadherins revealed that these molecules can activate signaling pathways leading to significant changes in gene expression. Although the expression patterns induced by E- and P-cadherin showed more similarities than differences, 40 genes were differentially modified by the expression of either cadherin type. Conclusion E- and P-cadherin have similar functional consequences on the phenotype and invasive behavior of MDA-MB-231 cells. Moreover, we demonstrate for the first time that these cadherins can induce both common and specific gene expression programs on invasive breast cancer cells. Importantly, these identified genes are potential targets for future studies on the functional consequences of altered cadherin expression in human breast cancer.

Expression of E-cadherin and vimentin in oral squamous cell carcinoma

Science.gov (United States)

Zhou, Jingping; Tao, Detao; Xu, Qing; Gao, Zhenlin; Tang, Daofang

2015-01-01

The aim of the study is to determine the levels of E-cadherin, vimentin expression in tumor tissues from patients with oral squamous cell carcinoma (OSCC), and the relationship between the expression of E-cadherin, vimentin and epithelial-mesenchymal transition, in order to explore its values for predicting the invasion and metastasis of oral squamous cell carcinoma, short survival of patients in many types of cancer. E-cadherin and vimentin expression of 10 benign and 42 OSCC tumor tissues was examined by immunohistochemical staining. E-cadherin is positively expressed in normal oral mucosa epithelium, but vimentin expression is not found in normal oral mucosa epithelia; the E-cadherin and vimentin were expressed in 26 of 42 (61.9%) and 16 of 42 (38.1%), respectively. No statistically difference was found for E-cadherin and vimentin expression in patients with different age, gender and tumor location, E-cadherin and vimentin expression was significantly associated with lymph node metastasis and tissue location (P oral squamous cell carcinoma for E-cadherin and vimentin positive expression (P oral squamous cell carcinoma. Our study preliminarily confirmed that EMT phenomenon is existed during the development of oral squamous cell carcinoma. Co-evaluation of E-cadherin and vimentin might be a valuable tool for predicting OSCC patient outcome. PMID:26045832

N-cadherin Expression in Testicular Germ Cell and Gonadal Stromal Tumors

Directory of Open Access Journals (Sweden)

Daniel J. Heidenberg, Joel H. Barton, Denise Young, Michael Grinkemeyer, Isabell A. Sesterhenn

2012-01-01

Full Text Available Neural-cadherin is a member of the cadherin gene family encoding the N-cadherin protein that mediates cell adhesion. N-cadherin is a marker of Sertoli cells and is also expressed in germ cells of varying stages of maturation. The purpose of this study was to determine the presence and distribution of this protein by immunohistochemistry in 105 germ cell tumors of both single and mixed histological types and 12 gonadal stromal tumors. Twenty-four germ cell tumors consisted of one cell type and the remaining were mixed. Of the 23 seminomas in either pure or mixed tumors, 74% were positive. Two spermatocytic seminomas were positive. Of the 83 cases with yolk sac tumor, 99% were positive for N-cadherin. The teratomas were positive in 73% in neuroectodermal and / or glandular components. In contrast, 87% of embryonal carcinomas did not express N-cadherin. Only 17% of the syncytiotrophoblastic cells were positive for N-cadherin. In conclusion, N-cadherin expression is very helpful in the identification of yolk sac tumors. In addition to glypican-3 and Sal-like protein 4, N-cadherin can be beneficial for the diagnosis and classification of this subtype of testicular germ cell tumor. Nine of the 12 gonadal stromal tumors were positive to a variable extent.

ADAM13 cleavage of cadherin-11 promotes CNC migration independently of the homophilic binding site.

Science.gov (United States)

Abbruzzese, Genevieve; Becker, Sarah F; Kashef, Jubin; Alfandari, Dominique

2016-07-15

The cranial neural crest (CNC) is a highly motile population of cells that is responsible for forming the face and jaw in all vertebrates and perturbing their migration can lead to craniofacial birth defects. Cell motility requires a dynamic modification of cell-cell and cell-matrix adhesion. In the CNC, cleavage of the cell adhesion molecule cadherin-11 by ADAM13 is essential for cell migration. This cleavage generates a shed extracellular fragment of cadherin-11 (EC1-3) that possesses pro-migratory activity via an unknown mechanism. Cadherin-11 plays an important role in modulating contact inhibition of locomotion (CIL) in the CNC to regulate directional cell migration. Here, we show that while the integral cadherin-11 requires the homophilic binding site to promote CNC migration in vivo, the EC1-3 fragment does not. In addition, we show that increased ADAM13 activity or expression of the EC1-3 fragment increases CNC invasiveness in vitro and blocks the repulsive CIL response in colliding cells. This activity requires the presence of an intact homophilic binding site on the EC1-3 suggesting that the cleavage fragment may function as a competitive inhibitor of cadherin-11 adhesion in CIL but not to promote cell migration in vivo. Copyright © 2015. Published by Elsevier Inc.

CD8 T-cells and E-cadherin in host responses against oropharyngeal candidiasis

Science.gov (United States)

Quimby, K.; Lilly, E.A.; Zacharek, M.; McNulty, K.; Leigh, J.E.; Vazquez, J.E.; Fidel, P.L.

2011-01-01

Oropharyngeal candidiasis (OPC) is the most common oral infection in HIV+ persons. Previous studies suggest a role for CD8+ T-cells against OPC when CD4+ T-cells are lost, but enhanced susceptibility to infection occurs when CD8+ T-cell migration is inhibited by reduced tissue E-cadherin. Objective Conduct a longitudinal study of tissue CD8+ T-cells and E-cadherin expression before, during, and after episodes of OPC. Methods Oral fungal burden was monitored and tissue was evaluated for CD8+ T-cells and E-cadherin over a one-year period in HIV+ persons with a history of, or an acute episode of OPC. Results While longitudinal analyses precluded formal interpretations, point prevalence analyses of the dataset revealed that when patients experiencing OPC were successfully treated, tissue E-cadherin expression was similar to patients who had not experienced OPC, and higher numbers of CD8+ T-cells were distributed throughout OPC− tissue under normal expression of E-cadherin. Conclusion These results suggest that 1) reduction in tissue E-cadherin expression in OPC+ patients is not permanent, and 2) high numbers of CD8+ T-cells can be distributed throughout OPC− tissue under normal E-cadherin expression. Together these results extend our previous studies and continue to support a role for CD8+ T-cells in host defense against OPC. PMID:21958417

Invasive lobular breast cancer: the prognostic impact of histopathological grade, E-cadherin and molecular subtypes.

Science.gov (United States)

Engstrøm, Monica J; Opdahl, Signe; Vatten, Lars J; Haugen, Olav A; Bofin, Anna M

2015-02-01

The aim of this study was to compare breast cancer specific survival (BCSS) for invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC) and, further, to evaluate critically the prognostic value of histopathological grading of ILC and examine E-cadherin as a prognostic marker in ILC. The study comprised 116 lobular and 611 ductal breast carcinomas occurring between 1961 and 2008. All cases had been classified previously according to histopathological type and grade, stained for oestrogen receptor (ER), progesterone receptor (PR), antigen Ki67 (Ki67), epithelial growth factor receptor (EGFR), cytokeratin 5 (CK5) and human epidermal growth factor receptor 2 (HER2) and classified into molecular subtypes. For the present study, immunohistochemical staining for E-cadherin was performed. The Kaplan-Meier method and Cox proportional hazards models were used in the analyses. Grade 2 tumours comprised 85.3% of the lobular tumours and 51.9% of the ductal tumours. BCSS in ILC grade 2 was comparable to that of IDC grade 3. E-cadherin-negative ILC had a poorer prognosis compared to E-cadherin positive ILC and to IDC regardless of E-cadherin status. The implication of histopathological grading may differ in ILC compared to IDC. E-cadherin may be useful in prognostication in ILC and thereby influence the determination of treatment strategies for this group of women. © 2014 The Authors. Histopathology published by John Wiley & Sons Ltd.

Soluble Neural-cadherin as a novel biomarker for malignant bone and soft tissue tumors

International Nuclear Information System (INIS)

Niimi, Rui; Matsumine, Akihiko; Iino, Takahiro; Nakazora, Shigeto; Nakamura, Tomoki; Uchida, Atsumasa; Sudo, Akihiro

2013-01-01

Neural-cadherin (N-cadherin) is one of the most important molecules involved in tissue morphogenesis, wound healing, and the maintenance of tissue integrity. Recently, the cleavage of N-cadherin has become a focus of attention in the field of cancer biology. Cadherin and their ectodomain proteolytic shedding play important roles during cancer progression. The aims of this study are to investigate the serum soluble N-cadherin (sN-CAD) levels in patients with malignant bone and soft tissue tumors, and to evaluate the prognostic significance of the sN-CAD levels. We examined the level of serum sN-CAD using an ELISA in 80 malignant bone and soft tissue tumors (bone sarcoma, n = 23; soft tissue sarcoma, n = 50; metastatic cancer, n = 7) and 87 normal controls. The mean age of the patients was 51 years (range, 10–85 years) and the mean follow-up period was 43 months (range, 1–115 months). The median serum sN-CAD level was 1,267 ng/ml (range, 135–2,860 ng/ml) in all patients. The mean serum sN-CAD level was 1,269 ng/ml (range, 360–2,860 ng/ml) in sarcoma patients, otherwise 1,246 ng/ml (range, 135–2,140 ng/ml) in cancer patients. The sN-CAD levels in patient were higher than those found in the controls, who had a median serum level of 108 ng/ml (range, 0–540 ng/ml). The patients with tumors larger than 5 cm had higher serum sN-CAD levels than the patients with tumors smaller than 5 cm. The histological grade in the patients with higher serum sN-CAD levels was higher than that in the patients with lower serum sN-CAD levels. A univariate analysis demonstrated that the patients with higher serum sN-CAD levels showed a worse disease-free survival rate, local recurrence-free survival rate, metastasis-free survival rate, and overall survival rate compared to those with lower serum sN-CAD levels. In the multivariate analysis, sN-CAD was an independent factor predicting disease-free survival. sN-CAD is a biomarker for malignant bone and soft tissue tumors, and a

Fragments of e-Cadherin as Biomarkers of Non-erosive Reflux Disease.

Science.gov (United States)

Jovov, Biljana; Reed, Craig C; Shaheen, Nicholas J; Pruitt, Amy; Ferrell, Kathleen; Orlando, Geraldine S; Djukic, Zorka; Orlando, Roy C

2018-03-01

Approximately, 20% of patients with heartburn and normal endoscopic findings do not symptomatically improve on proton pump inhibitor (PPI) therapy making diagnosis and treatment uncertain. A biomarker distinguishing PPI-responsive from PPI-refractory heartburn is desirable. We performed a pilot study assessing whether carboxy(C)-terminal fragments (CTFs) of e-cadherin in esophageal biopsies or amino(N)-terminal fragments (NTFs) of e-cadherin in serum could serve this purpose. Twenty-nine patients with endoscopy-negative heartburn had esophageal biopsies for CTFs on Western blot and blood for serum NTFs on ELISA. All patients received dexlansoprazole 30 mg daily for 4 weeks, and heartburn was assessed by daily diary entry. Post-treatment blood samples were obtained for serum NTFs. A control group without GERD symptoms (n = 6) had biopsies for CTFs and a second control group (n = 20) blood serum for serum NTFs. Twenty-seven of 29 patients (93.1%) with endoscopy-negative heartburn, but 0 of 6 controls, were positive for CTFs. All patients and controls had measureable serum NTFs, but mean NTFs were significantly higher in those with PPI-responsive heartburn compared to those with PPI-refractory heartburn and controls. Following treatment, 24 of 29 (82.8) patients had relief of heartburn, which associated with a decline in mean NTFs compared to controls. NTFs in PPI-refractory patients (n = 5) were similar to controls before and after PPI therapy. When heartburn responds to PPI, elevated serum NTFs decline to normal. These data suggest that cleaved products of e-cadherin may serve as biomarkers of NERD. Further data are needed to assess and confirm this concept.

E-cadherin is required for centrosome and spindle orientation in Drosophila male germline stem cells.

Directory of Open Access Journals (Sweden)

Mayu Inaba

2010-08-01

Full Text Available Many adult stem cells reside in a special microenvironment known as the niche, where they receive essential signals that specify stem cell identity. Cell-cell adhesion mediated by cadherin and integrin plays a crucial role in maintaining stem cells within the niche. In Drosophila melanogaster, male germline stem cells (GSCs are attached to niche component cells (i.e., the hub via adherens junctions. The GSC centrosomes and spindle are oriented toward the hub-GSC junction, where E-cadherin-based adherens junctions are highly concentrated. For this reason, adherens junctions are thought to provide a polarity cue for GSCs to enable proper orientation of centrosomes and spindles, a critical step toward asymmetric stem cell division. However, understanding the role of E-cadherin in GSC polarity has been challenging, since GSCs carrying E-cadherin mutations are not maintained in the niche. Here, we tested whether E-cadherin is required for GSC polarity by expressing a dominant-negative form of E-cadherin. We found that E-cadherin is indeed required for polarizing GSCs toward the hub cells, an effect that may be mediated by Apc2. We also demonstrated that E-cadherin is required for the GSC centrosome orientation checkpoint, which prevents mitosis when centrosomes are not correctly oriented. We propose that E-cadherin orchestrates multiple aspects of stem cell behavior, including polarization of stem cells toward the stem cell-niche interface and adhesion of stem cells to the niche supporting cells.

Effect of radiation on the expression of E-cadherin and α-catenin and invasive capacity in human lung cancer cell line in vitro

International Nuclear Information System (INIS)

Akimoto, Tetsuo; Mitsuhashi, Norio; Saito, Yoshihiro; Ebara, Takeshi; Niibe, Hideo

1998-01-01

Purpose: To investigate the effect of radiation on E-cadherin and α-catenin expression in a human lung cancer cell line, and also evaluate invasive capacity in the membrane invasion culture system using the Boyden Chamber. Materials and Methods: The immunoblot and immunofluorescence analyses were performed using the human lung cancer cell line A549 to examine altered expression of E-cadherin and α-catenin after irradiation. We also compared invasive capacity of untreated cells with that of irradiated cells. Results: Immunoblot analysis revealed that the expression of E-cadherin increased after irradiation. In a time-course analysis, the expression was increased 6 h after irradiation with 10 Gy and reached its peak level at 24 h, being 2.3 times the control value, whereas expression at 1 and 3 h after irradiation was almost equivalent to that of the control. A slight increase in expression was observed after irradiation of 2 Gy and the expression reached peak levels after 5 Gy. After fractionated irradiation, the increase in expression of both E-cadherin and α-catenin was observed, and the alteration of α-catenin was more prominent than that after a single irradiation of the same total dose. In the immunofluorescence study for E-cadherin antibody analyzed by confocal laser scanning microscopy, increased intensity in irradiated cells produced as a nondisrupted and continuous line at cell-cell contact sites. In an invasive assay, the number of migrated cells in irradiated cells after a dose of 5 and 10 Gy was reduced significantly compared to untreated cells. Conclusion: The results indicate that irradiation of A549 increased the expression of E-cadherin, possibly preserving their functional property

Clinicopathological significance of ZEB-1 and E-cadherin proteins in patients with oral cavity squamous cell carcinoma

Directory of Open Access Journals (Sweden)

Yao X

2017-02-01

Full Text Available Xiaofeng Yao,1,2 Shanshan Sun,1,2 Xuan Zhou,1,2 Qiang Zhang,1,2 Wenyu Guo,1,2 Lun Zhang1,2 1Department of Maxillofacial and Otorhinolaryngology Head and Neck Surgery, Tianjin Medical University Cancer Institute and Hospital, 2Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center of Cancer, Tianjin, People’s Republic of China Background: Zinc-finger E-box binding homeobox 1 (ZEB-1, a member of the ZFH family, plays a key role in epithelial–mesenchymal transition during tumor progression in various cancers. However, little information is available on ZEB-1 expression in oral cavity squamous cell carcinoma (OSCC.Methods: The expression levels of ZEB-1 and E-cadherin were assessed by immunohistochemistry in a cohort of 120 patients with OSCC treated by curative operation, and then the correlations between ZEB-1 and E-cadherin expression and clinical factors were evaluated, including patient prognosis. Quantitative real-time polymerase chain reaction (qRT-PCR assays were performed to assess mRNA levels of ZEB-1 and E-cadherin in 20 matched OSCC specimens.Results: Patients were followed up for a median period of 66 months (range 8-116 months, and 5-year overall survival was 68.3%. Positive ZEB-1 and E-cadherin immunostaining reactivity was detected in 64 (53.3% and 53 (44.2% patients, respectively. There was a negative correlation between ZEB-1 expression and E-cadherin expression. In addition, overexpression of ZEB-1 was significantly associated with recurrence, lymph node metastasis, and pathologic grading of patients, loss of E-cadherin was significantly associated with lymph node metastasis and pathologic grading of patients. Univariate analysis showed that increased ZEB-1 expression, loss of E-cadherin expression, lymph node metastasis, recurrence, and pathology grade were prognostic factors. In multivariate analysis, increased ZEB-1 expression and recurrence remained independent prognostic factors. In particular

Impact of pH on the structure and function of neural cadherin.

Science.gov (United States)

Jungles, Jared M; Dukes, Matthew P; Vunnam, Nagamani; Pedigo, Susan

2014-12-02

Neural (N-) cadherin is a transmembrane protein within adherens junctions that mediates cell-cell adhesion. It has 5 modular extracellular domains (EC1-EC5) that bind 3 calcium ions between each of the modules. Calcium binding is required for dimerization. N-Cadherin is involved in diverse processes including tissue morphogenesis, excitatory synapse formation and dynamics, and metastasis of cancer. During neurotransmission and tumorigenesis, fluctuations in extracellular pH occur, causing tissue acidosis with associated physiological consequences. Studies reported here aim to determine the effect of pH on the dimerization properties of a truncated construct of N-cadherin containing EC1-EC2. Since N-cadherin is an anionic protein, we hypothesized that acidification of solution would cause an increase in stability of the apo protein, a decrease in the calcium-binding affinity, and a concomitant decrease in the formation of adhesive dimer. The stability of the apo monomer was increased and the calcium-binding affinity was decreased at reduced pH, consistent with our hypothesis. Surprisingly, analytical SEC studies showed an increase in calcium-induced dimerization as solution pH decreased from 7.4 to 5.0. Salt-dependent dimerization studies indicated that electrostatic repulsion attenuates dimerization affinity. These results point to a possible electrostatic mechanism for moderating dimerization affinity of the Type I cadherin family. Extrapolating these results to cell adhesion in vivo leads to the assertion that decreased pH promotes adhesion by N-cadherin, thereby stabilizing synaptic junctions.

A single type of cadherin is involved in Bacillus thuringiensis toxicity in Plutella xylostella.

Science.gov (United States)

Park, Y; Herrero, S; Kim, Y

2015-12-01

Cadherins have been described as one the main functional receptors for the toxins of the entomopathogenic bacterium, Bacillus thuringiensis (Bt). With the availability of the whole genome of Plutella xylostella, different types of cadherins have been annotated. In this study we focused on determining those members of the cadherin-related proteins that potentially play a role in the mode of action of Bt toxins. For this, we mined the genome of P. xylostella to identify these putative cadherins. The genome screening revealed 52 genes that were annotated as cadherin or cadherin-like genes. Further analysis revealed that six of these putative cadherins had three motifs common to all Bt-related cadherins: a signal peptide, cadherin repeats and a transmembrane domain. From the six selected cadherins, only P. xylostella cadherin 1 (PxCad1) was expressed in the larval midgut and only the silencing of this gene by RNA interference (double-stranded RNA feeding) reduce toxicity and binding to the midgut of the Cry1Ac type toxin from Bt. These results indicate that from the whole set of cadherin-related genes identified in P. xylostella, only PxCad1 is associated with the Cry1Ac mode of action. © 2015 The Royal Entomological Society.

Membrane fluctuations mediate lateral interaction between cadherin bonds

Science.gov (United States)

Fenz, Susanne F.; Bihr, Timo; Schmidt, Daniel; Merkel, Rudolf; Seifert, Udo; Sengupta, Kheya; Smith, Ana-Sunčana

2017-09-01

The integrity of living tissues is maintained by adhesion domains of trans-bonds formed between cadherin proteins residing on opposing membranes of neighbouring cells. These domains are stabilized by lateral cis-interactions between the cadherins on the same cell. However, the origin of cis-interactions remains perplexing since they are detected only in the context of trans-bonds. By combining experimental, analytical and computational approaches, we identify bending fluctuations of membranes as a source of long-range cis-interactions, and a regulator of trans-interactions. Specifically, nanometric membrane bending and fluctuations introduce cooperative effects that modulate the affinity and binding/unbinding rates for trans-dimerization, dramatically affecting the nucleation and growth of adhesion domains. Importantly, this regulation relies on physical principles and not on details of protein-protein interactions. These omnipresent fluctuations can thus act as a generic control mechanism in all types of cell adhesion, suggesting a hitherto unknown physiological role for recently identified active fluctuations of cellular membranes.

E-cadherin junction formation involves an active kinetic nucleation process

Science.gov (United States)

Biswas, Kabir H.; Hartman, Kevin L.; Yu, Cheng-han; Harrison, Oliver J.; Song, Hang; Smith, Adam W.; Huang, William Y. C.; Lin, Wan-Chen; Guo, Zhenhuan; Padmanabhan, Anup; Troyanovsky, Sergey M.; Dustin, Michael L.; Shapiro, Lawrence; Honig, Barry; Zaidel-Bar, Ronen; Groves, Jay T.

2015-01-01

Epithelial (E)-cadherin-mediated cell−cell junctions play important roles in the development and maintenance of tissue structure in multicellular organisms. E-cadherin adhesion is thus a key element of the cellular microenvironment that provides both mechanical and biochemical signaling inputs. Here, we report in vitro reconstitution of junction-like structures between native E-cadherin in living cells and the extracellular domain of E-cadherin (E-cad-ECD) in a supported membrane. Junction formation in this hybrid live cell-supported membrane configuration requires both active processes within the living cell and a supported membrane with low E-cad-ECD mobility. The hybrid junctions recruit α-catenin and exhibit remodeled cortical actin. Observations suggest that the initial stages of junction formation in this hybrid system depend on the trans but not the cis interactions between E-cadherin molecules, and proceed via a nucleation process in which protrusion and retraction of filopodia play a key role. PMID:26290581

Controlled Directional Growth of TiO2 Nanotubes

DEFF Research Database (Denmark)

In, Su-il; Hou, Yidong; Abrams, Billie

2010-01-01

We demonstrate how the anodization direction and growth rate of vertically aligned, highly ordered TiO2 nanotube (NT) arrays can be controlled and manipulated by the local concentration of O-2 in the electrolyte. This leads to the growth of highly active TiO2 NT arrays directly on nonconducting s...

Spatiotemporal distribution and function of N-cadherin in postnatal Schwann cells: A matter of adhesion?

DEFF Research Database (Denmark)

Corell, Mikael; Wicher, Grzegorz; Limbach, Christoph

2010-01-01

During embryonic development of the peripheral nervous system (PNS), the adhesion molecule neuronal cadherin (N-cadherin) is expressed by Schwann cell precursors and associated with axonal growth cones. N-cadherin expression levels decrease as precursors differentiate into Schwann cells. In this ......During embryonic development of the peripheral nervous system (PNS), the adhesion molecule neuronal cadherin (N-cadherin) is expressed by Schwann cell precursors and associated with axonal growth cones. N-cadherin expression levels decrease as precursors differentiate into Schwann cells....... In this study, we investigated the distribution of N-cadherin in the developing postnatal and adult rat peripheral nervous system. N-cadherin was found primarily in ensheathing glia throughout development, concentrated at neuron-glial or glial-glial contacts of the sciatic nerve, dorsal root ganglia (DRG......), and myenteric plexi. In the sciatic nerve, N-cadherin decreases with age and progress of myelination. In adult animals, N-cadherin was found exclusively in nonmyelinating Schwann cells. The distribution of N-cadherin in developing E17 DRG primary cultures is similar to what was observed in vivo. Functional...

Rac1 activation inhibits E-cadherin-mediated adherens junctions via binding to IQGAP1 in pancreatic carcinoma cells

Directory of Open Access Journals (Sweden)

Giehl Klaudia

2009-09-01

Full Text Available Abstract Background Monomeric GTPases of the Rho family control a variety of cellular functions including actin cytoskeleton organisation, cell migration and cell adhesion. Defects in these regulatory processes are involved in tumour progression and metastasis. The development of metastatic carcinoma is accompanied by deregulation of adherens junctions, which are composed of E-cadherin/β- and α-catenin complexes. Results Here, we show that the activity of the monomeric GTPase Rac1 contributes to inhibition of E-cadherin-mediated cell-cell adhesion in pancreatic carcinoma cells. Stable expression of constitutively active Rac1(V12 reduced the amount of E-cadherin on protein level in PANC-1 pancreatic carcinoma cells, whereas expression of dominant negative Rac1(N17 resulted in an increased amount of E-cadherin. Extraction of proteins associated with the actin cytoskeleton as well as coimmunoprecipitation analyses demonstrated markedly decreased amounts of E-cadherin/catenin complexes in Rac1(V12-expressing cells, but increased amounts of functional E-cadherin/catenin complexes in cells expressing Rac1(N17. Cell aggregation and migration assays revealed, that cells containing less E-cadherin due to expression of Rac1(V12, exhibited reduced cell-cell adhesion and increased cell motility. The Rac/Cdc42 effector protein IQGAP1 has been implicated in regulating cell-cell adhesion. Coimmunoprecipitation studies showed a decrease in the association between IQGAP1 and β-catenin in Rac1(V12-expressing PANC-1 cells and an association of IQGAP1 with Rac1(V12. Elevated association of IQGAP1 with the E-cadherin adhesion complex via β-catenin correlated with increased intercellular adhesion of PANC-1 cells. Conclusion These results indicate that active Rac1 destabilises E-cadherin-mediated cell-cell adhesion in pancreatic carcinoma cells by interacting with IQGAP1 which is associated with a disassembly of E-cadherin-mediated adherens junctions. Inhibition

Correlation of serum MCP-1 and VE-cadherin levels with neural function and carotid atherosclerosis in patients with acute cerebral infarction

Directory of Open Access Journals (Sweden)

Yan-Bing Xi

2017-05-01

Full Text Available Objective: To study the correlation of serum monocyte chemoattractant protein-1 (MCP-1 and vascular endothelial cadherin (VE-cadherin levels with neural function and carotid atherosclerosis in patients with acute cerebral infarction. Methods: A total of 78 patients who were diagnosed with acute cerebral infarction in our hospital between May 2013 and August 2016 were selected as pathological group, and 80 healthy volunteers who received physical examination in our hospital during the same period were selected as control group. Serum was collected to determine the levels of MCP-1, VE-cadherin, nerve injury molecules, inflammatory mediators, proteases and their hydrolysate. Results: Serum MCP-1, VE-cadherin, NGB, NSE, S100β, HMGB-1, sCD40L, YKL-40, visfatin, CatK, MMP9 and ICTP levels of pathological group were significantly higher than those of control group; serum MCP-1 and VE-cadherin levels of pathological group were positively correlated with NGB, NSE, S100β, HMGB-1, sCD40L, YKL-40, visfatin, CatK, MMP9 and ICTP levels. Conclusion: Serum MCP-1 and VE-cadherin levels abnormally increase in patients with acute cerebral infarction, and are closely related to the nerve injury and atherosclerosis process.

Patients treatment with neuroglioma by teniposide and semustine and its influence on Twist and E-cadherin expression

Directory of Open Access Journals (Sweden)

Yongbo Zhang

2016-05-01

Full Text Available This study focuses on curative effects of teniposide combining with semustine on patients with neuroglioma and the influences on the expression of Twist and E-cadherin in tissue. Sixty-eight patients with neuroglioma taking operation in our hospital were divided into two groups randomly. Single radiotherapy was given to 34 patients in group A, and teniposide (VM-26 and semustine (Me-CCUN were added to radiotherapy for 34 patients in group B. Then, curative effects, survival rate, living quality and adverse reaction rate after operation were compared between two groups. Moreover, the difference in positive expression rate of Twist and E-cadherin before and after treatment between two groups was analyzed by immunohistochemistry. Results: In group B, the effective rate of treatment was 88.2%, and the disease control rate was 70.6%, higher than 52.9% and 32.4% in group A with statistical significance (P  0.05. In addition, the difference in positive expression rate of Twist and E-cadherin between group A and group B has no statistical significance before treatment (P > 0.05. After treatment, however, the positive rate of Twist in group B is lower than that in group A, while the positive rate of E-cadherin is higher. Both differences have statistical significance (P < 0.05. Chemotherapy of VM-26 combining with Me-CCNU can inhibit Twist expression and improve the expression rate of E-cadherin to help improving the curative effects and living quality and increasing survival rate.

Myosin VIIa, harmonin and cadherin 23, three Usher I gene products that cooperate to shape the sensory hair cell bundle

Science.gov (United States)

Boëda, Batiste; El-Amraoui, Aziz; Bahloul, Amel; Goodyear, Richard; Daviet, Laurent; Blanchard, Stéphane; Perfettini, Isabelle; Fath, Karl R.; Shorte, Spencer; Reiners, Jan; Houdusse, Anne; Legrain, Pierre; Wolfrum, Uwe; Richardson, Guy; Petit, Christine

2002-01-01

Deaf-blindness in three distinct genetic forms of Usher type I syndrome (USH1) is caused by defects in myosin VIIa, harmonin and cadherin 23. Despite being critical for hearing, the functions of these proteins in the inner ear remain elusive. Here we show that harmonin, a PDZ domain-containing protein, and cadherin 23 are both present in the growing stereocilia and that they bind to each other. Moreover, we demonstrate that harmonin b is an F-actin-bundling protein, which is thus likely to anchor cadherin 23 to the stereocilia microfilaments, thereby identifying a novel anchorage mode of the cadherins to the actin cytoskeleton. Moreover, harmonin b interacts directly with myosin VIIa, and is absent from the disorganized hair bundles of myosin VIIa mutant mice, suggesting that myosin VIIa conveys harmonin b along the actin core of the developing stereocilia. We propose that the shaping of the hair bundle relies on a functional unit composed of myosin VIIa, harmonin b and cadherin 23 that is essential to ensure the cohesion of the stereocilia. PMID:12485990

The midgut cadherin-like gene is not associated with resistance to Bacillus thuringiensis toxin Cry1Ac in Plutella xylostella (L.).

Science.gov (United States)

Guo, Zhaojiang; Kang, Shi; Zhu, Xun; Wu, Qingjun; Wang, Shaoli; Xie, Wen; Zhang, Youjun

2015-03-01

The Gram-positive bacterium Bacillus thuringiensis (Bt) produces Cry toxins that have been used to control important agricultural pests. Evolution of resistance in target pests threatens the effectiveness of these toxins when used either in sprayed biopesticides or in Bt transgenic crops. Although alterations of the midgut cadherin-like receptor can lead to Bt Cry toxin resistance in many insects, whether the cadherin gene is involved in Cry1Ac resistance of Plutella xylostella (L.) remains unclear. Here, we present experimental evidence that resistance to Cry1Ac or Bt var. kurstaki (Btk) in P. xylostella is not due to alterations of the cadherin gene. The bona fide P. xylostella cadherin cDNA sequence was cloned and analyzed, and comparisons of the cadherin cDNA sequence among susceptible and resistant P. xylostella strains confirmed that Cry1Ac resistance was independent of mutations in this gene. In addition, real-time quantitative PCR (qPCR) indicated that cadherin transcript levels did not significantly differ among susceptible and resistant P. xylostella strains. RNA interference (RNAi)-mediated suppression of cadherin gene expression did not affect larval susceptibility to Cry1Ac toxin. Furthermore, genetic linkage assays using four cadherin gDNA allelic biomarkers confirmed that the cadherin gene is not linked to resistance against Cry1Ac in P. xylostella. Taken together, our findings demonstrate that Cry1Ac resistance of P. xylostella is independent of the cadherin gene. Copyright © 2015 Elsevier Inc. All rights reserved.

Tissue organization by cadherin adhesion molecules: dynamic molecular and cellular mechanisms of morphogenetic regulation

Science.gov (United States)

Niessen, Carien M.; Leckband, Deborah; Yap, Alpha S.

2013-01-01

This review addresses the cellular and molecular mechanisms of cadherin-based tissue morphogenesis. Tissue physiology is profoundly influenced by the distinctive organizations of cells in organs and tissues. In metazoa, adhesion receptors of the classical cadherin family play important roles in establishing and maintaining such tissue organization. Indeed, it is apparent that cadherins participate in a range of morphogenetic events that range from support of tissue integrity to dynamic cellular rearrangements. A comprehensive understanding of cadherin-based morphogenesis must then define the molecular and cellular mechanisms that support these distinct cadherin biologies. Here we focus on four key mechanistic elements: the molecular basis for adhesion through cadherin ectodomains; the regulation of cadherin expression at the cell surface; cooperation between cadherins and the actin cytoskeleton; and regulation by cell signaling. We discuss current progress and outline issues for further research in these fields. PMID:21527735

The Nonreceptor Protein Tyrosine Phosphatase PTP1B Binds to the Cytoplasmic Domain of N-Cadherin and Regulates the Cadherin–Actin Linkage

Science.gov (United States)

Balsamo, Janne; Arregui, Carlos; Leung, TinChung; Lilien, Jack

1998-01-01

Cadherin-mediated adhesion depends on the association of its cytoplasmic domain with the actin-containing cytoskeleton. This interaction is mediated by a group of cytoplasmic proteins: α-and β- or γ- catenin. Phosphorylation of β-catenin on tyrosine residues plays a role in controlling this association and, therefore, cadherin function. Previous work from our laboratory suggested that a nonreceptor protein tyrosine phosphatase, bound to the cytoplasmic domain of N-cadherin, is responsible for removing tyrosine-bound phosphate residues from β-catenin, thus maintaining the cadherin–actin connection (Balsamo et al., 1996). Here we report the molecular cloning of the cadherin-associated tyrosine phosphatase and identify it as PTP1B. To definitively establish a causal relationship between the function of cadherin-bound PTP1B and cadherin-mediated adhesion, we tested the effect of expressing a catalytically inactive form of PTP1B in L cells constitutively expressing N-cadherin. We find that expression of the catalytically inactive PTP1B results in reduced cadherin-mediated adhesion. Furthermore, cadherin is uncoupled from its association with actin, and β-catenin shows increased phosphorylation on tyrosine residues when compared with parental cells or cells transfected with the wild-type PTP1B. Both the transfected wild-type and the mutant PTP1B are found associated with N-cadherin, and recombinant mutant PTP1B binds to N-cadherin in vitro, indicating that the catalytically inactive form acts as a dominant negative, displacing endogenous PTP1B, and rendering cadherin nonfunctional. Our results demonstrate a role for PTP1B in regulating cadherin-mediated cell adhesion. PMID:9786960

E-cadherin and beta-catenin are down-regulated in prostatic bone metastases.

Science.gov (United States)

Bryden, A A G; Hoyland, J A; Freemont, A J; Clarke, N W; Schembri Wismayer, D; George, N J R

2002-03-01

To determine the E-cadherin and beta-catenin expression phenotype in untreated primary prostate cancer and corresponding bone metastases. Paired bone metastasis and primary prostate specimens were obtained from 14 men with untreated metastatic prostate carcinoma. The tumours were histologically graded by an independent pathologist. Expression of mRNA for E-cadherin and beta-catenin was detected within the tumour cells using in-situ hybridization with a 35S-labelled cDNA probe. The expression of E-cadherin and beta-catenin were graded as uniform, heterogeneous or negative. The mRNA for E-cadherin was expressed in 13 of 14 primary carcinomas and 11 bone metastases; beta-catenin was expressed by 13 and nine, respectively. Of the primary tumours, nine expressed E-cadherin and beta-catenin uniformly; in contrast, all metastases had down-regulated E-cadherin and/or beta-catenin. The down-regulation of E-cadherin and beta-catenin are a feature of the metastatic phenotype, which may be a significant factor in the genesis of bone metastases. However, this does not appear to be reflected in the expression of these molecules in the primary tumours.

P120-Catenin Regulates Early Trafficking Stages of the N-Cadherin Precursor Complex.

Directory of Open Access Journals (Sweden)

Diana P Wehrendt

Full Text Available It is well established that binding of p120 catenin to the cytoplasmic domain of surface cadherin prevents cadherin endocytosis and degradation, contributing to cell-cell adhesion. In the present work we show that p120 catenin bound to the N-cadherin precursor, contributes to its anterograde movement from the endoplasmic reticulum (ER to the Golgi complex. In HeLa cells, depletion of p120 expression, or blocking its binding to N-cadherin, increased the accumulation of the precursor in the ER, while it decreased the localization of mature N-cadherin at intercellular junctions. Reconstitution experiments in p120-deficient SW48 cells with all three major isoforms of p120 (1, 3 and 4 had similar capacity to promote the processing of the N-cadherin precursor to the mature form, and its localization at cell-cell junctions. P120 catenin and protein tyrosine phosphatase PTP1B facilitated the recruitment of the N-ethylmaleimide sensitive factor (NSF, an ATPase involved in vesicular trafficking, to the N-cadherin precursor complex. Dominant negative NSF E329Q impaired N-cadherin trafficking, maturation and localization at cell-cell junctions. Our results uncover a new role for p120 catenin bound to the N-cadherin precursor ensuring its trafficking through the biosynthetic pathway towards the cell surface.

Characterization of E-cadherin-dependent and -independent events in a new model of c-Fos-mediated epithelial-mesenchymal transition

International Nuclear Information System (INIS)

Mejlvang, Jakob; Kriajevska, Marina; Berditchevski, Fedor; Bronstein, Igor; Lukanidin, Eugene M.; Pringle, J. Howard; Mellon, J. Kilian; Tulchinsky, Eugene M.

2007-01-01

Fos proteins have been implicated in control of tumorigenesis-related genetic programs including invasion, angiogenesis, cell proliferation and apoptosis. In this study, we demonstrate that c-Fos is able to induce mesenchymal transition in murine tumorigenic epithelial cell lines. Expression of c-Fos in MT1TC1 cells led to prominent alterations in cell morphology, increased expression of mesenchymal markers, vimentin and S100A4, DNA methylation-dependent down-regulation of E-cadherin and abrogation of cell-cell adhesion. In addition, c-Fos induced a strong β-catenin-independent proliferative response in MT1TC1 cells and stimulated cell motility, invasion and adhesion to different extracellular matrix proteins. To explore whether loss of E-cadherin plays a role in c-Fos-mediated mesenchymal transition, we expressed wild-type E-cadherin and two different E-cadherin mutants in MT1TC1/c-fos cells. Expression of wild-type E-cadherin restored epithelioid morphology and enhanced cellular levels of catenins. However, exogenous E-cadherin did not influence expression of c-Fos-dependent genes, only partly suppressed growth of MT1TC1/c-fos cells and produced no effect on c-Fos-stimulated cell motility and invasion in matrigel. On the other hand, re-expression of E-cadherin specifically negated c-Fos-induced adhesion to collagen type I, but not to laminin or fibronectin. Of interest, mutant E-cadherin which lacks the ability to form functional adhesive complexes had an opposite, potentiating effect on cell adhesion to collagen I. These data suggest that cell adhesion to collagen I is regulated by the functional state of E-cadherin. Overall, our data demonstrate that, with the exception of adhesion to collagen I, c-Fos is dominant over E-cadherin in relation to the aspects of mesenchymal transition assayed in this study

E-cadherin and CD10 expression in atypical hyperplastic and malignant endometrial lesions

International Nuclear Information System (INIS)

Ahmed, A.R.H.; Muhammad, E.M.S.

2014-01-01

Background: Loss of E-cadherin is a critical step for development and progression of malignant tumors. CD10; a marker of non-neoplastic and neoplastic endometrial stroma, is associated with aggressiveness of many epithelial malignancies. Aims: To evaluate expression and correlation of E-cadherin and CD10 in endometrial lesions and their possible role in differentiating atypical endometrial hyperplasia from endometrial carcinoma. The association of E-cadherin and CD10 expression with clinico-pathological parameters of endometrial carcinoma was also investigated. Materials and methods: Fifty four cases including 28 endometrial carcinomas; 19 endometrial hyperplasia and 7 cases of normal endometrial changes were enrolled for this study. The expression of E-cadherin and CD10 was evaluated by immunohistochemistry using the streptavidin–biotin technique. Results: There was a strong association between malignant change of endometrial glands and membrano- cytoplasmic localization of E-cadherin (p< 0.001). Expression of E-cadherin but not CD10 was significantly higher in endometrial carcinomas compared to atypical endometrial hyperplasia (p < 0.01). Expression of E-cadherin was not associated with CD10 expression in different endometrial lesions. High grade tumors expressed low levels of both E-cadherin (p<0.01) and CD10 (p < 0.05) and serous endometrial carcinoma had low E-cadherin and CD10 expression compared to endometrioid carcinoma (p< 0.01 and <0.05, respectively). Expression of both molecules showed no association with depth of tumor invasion or FIGO stage. Tumors with lower E-cadherin or CD10 expression had higher rates of vascular tumor emboli (p< 0.01 and <0.07, respectively). Conclusions: Although expression of E-cadherin and CD10 in endometrial lesions was not correlated, reduced expression of both molecules could be critical for progression of endometrial carcinoma.

N-cadherin in adult rat cardiomyocytes in culture. II. Spatio-temporal appearance of proteins involved in cell-cell contact and communication. Formation of two distinct N-cadherin/catenin complexes.

Science.gov (United States)

Hertig, C M; Butz, S; Koch, S; Eppenberger-Eberhardt, M; Kemler, R; Eppenberger, H M

1996-01-01

The spatio-temporal appearance and distribution of proteins forming the intercalated disc were investigated in adult rat cardiomyocytes (ARC). The 'redifferentiation model' of ARC involves extensive remodelling of the plasma membrane and of the myofibrillar apparatus. It represents a valuable system to elucidate the formation of cell-cell contact between cardiomyocytes and to assess the mechanisms by which different proteins involved in the cell-cell adhesion process are sorted in a precise manner to the sites of function. Appearance of N-cadherin, the catenins and connexin43 within newly formed adherens and gap junctions was studied. Here first evidence is provided for a formation of two distinct and separable N-cadherin/catenin complexes in cardiomyocytes. Both complexes are composed of N-cadherin and alpha-catenin which bind to either beta-catenin or plakoglobin in a mutually exclusive manner. The two N-cadherin/catenin complexes are assumed to be functionally involved in the formation of cell-cell contacts in ARC; however, the differential appearance and localization of the two types of complexes may also point to a specific role during ARC differentiation. The newly synthesized beta-catenin containing complex is more abundant during the first stages in culture after ARC isolation, while the newly synthesized plakoglobin containing complex progressively accumulates during the morphological changes of ARC. ARC formed a tissue-like pattern in culture whereby the new cell-cell contacts could be dissolved through Ca2+ depletion. Presence of cAMP and replenishment of Ca2+ content in the culture medium not only allowed reformation of cell-cell contacts but also affected the relative protein ratio between the two N-cadherin/catenin complexes, increasing the relative amount of newly synthesized beta-catenin over plakoglobin at a particular stage of ARC differentiation. The clustered N-cadherin/catenin complexes at the plasma membrane appear to be a prerequisite for the

Influence of intra-tumoral heterogeneity on the evaluation of BCL2, E-cadherin, EGFR, EMMPRIN, and Ki-67 expression in tissue microarrays from breast cancer

DEFF Research Database (Denmark)

Tramm, Trine; Kyndi, Marianne; Sørensen, Flemming B

2018-01-01

-tumoral heterogeneity as well as inter-observer variability on the evaluation of various IHC markers with potential prognostic impact in breast cancer (BCL2, E-cadherin, EGFR, EMMPRIN and Ki-67). MATERIAL AND METHODS: From each of 27 breast cancer patients, two tumor-containing paraffin blocks were chosen. Intra...... was found. EMMPRIN and Ki-67 showed a more heterogeneous expression with moderate to substantial intra-block agreements. For both stainings, there was a moderate inter-block agreement that improved slightly for EMMPRIN, when using WS instead of TMA cores. Inter-observer agreements were found to be almost...... perfect for BCL2, E-cadherin and EGFR (WS: κ > 0.82, TMAs: κ > 0.90), substantial for EMMPRIN (κ > 0.63), but only fair to moderate for Ki-67 (WS: κ = 0.54, TMAs: κ = 0.33). CONCLUSIONS: BCL2, E-cadherin and EGFR were found to be homogeneously expressed, whereas EMMPRIN and Ki-67 showed a more pronounced...

Loss of functional E-cadherin renders cells more resistant to the apoptotic agent taxol in vitro

International Nuclear Information System (INIS)

Ferreira, Paulo; Oliveira, Maria Jose; Beraldi, Eliana; Mateus, Ana Rita; Nakajima, Takashi; Gleave, Martin; Yokota, Jun; Carneiro, Fatima; Huntsman, David; Seruca, Raquel; Suriano, Gianpaolo

2005-01-01

Experimental evidence supports a role for E-cadherin in suppressing invasion, metastasis, and proliferation. Germline mutations of the E-cadherin represent the genetic cause of hereditary diffuse gastric cancer (HDGC). In this type of tumor, isolated cancer cells permeate the basal membrane and paradoxically survive in the gastric wall in the absence of contact with neighbor epithelial cells or with the extracellular matrix. This suggests that upon E-cadherin deregulation, cells acquired resistance to apoptosis. To test this hypothesis, CHO cells stably expressing either wild-type E-cadherin or the HDGC-related germline mutations T340A and V832M were seeded either on a thin layer of collagen type I or on plastic and then subjected to the apoptotic agent taxol. We found that in vitro functional E-cadherin renders cells more sensitive to the effect of taxol. Our results also indicate that this effect is associated to decreased level of the anti-apoptotic bcl-2 protein

Soluble E-Cadherin: An Early Marker of Severity in Acute Pancreatitis

Directory of Open Access Journals (Sweden)

A. Sewpaul

2009-01-01

Full Text Available Background/Aims. At present, there is no simple test for predicting severity in acute pancreatitis. We investigated the use of an assay of soluble E-cadherin (sE-cadherin. Methods. Concentrations of sE-cadherin, from 19 patients with mild acute pancreatitis, 7 patients with severe acute pancreatitis, 11 patients with other acute gastrointestinal pathologies, and 12 healthy subjects were measured using a commercially available sandwich ELISA kit based on two monoclonal antibodies specific to the extracellular fragment of human E-cadherin. Measurements were made at 12 hours or less from onset of pain and also at 24 and 48 hours after onset of pain. Results. Mean (standard deviation concentration of sE-cadherin in patients with severe acute pancreatitis at <12 hours was 17780 ng/mL (7853, significantly higher than that of healthy volunteers 5180 ng/mL (1350, =.0039, patients with other gastrointestinal pathologies 7358 ng/mL (6655, =.0073, and also significantly higher than that of patients with mild pancreatitis, 7332 ng/mL (2843, =.0019. Discussion. Serum sE-cadherin could be an early (within 12 hours objective marker of severity in acute pancreatitis. This molecule warrants further investigation in the form of a large multicentre trial.

E-cadherin gene re-expression in chronic lymphocytic leukemia cells by HDAC inhibitors

International Nuclear Information System (INIS)

Jordaan, Gwen; Liao, Wei; Sharma, Sanjai

2013-01-01

The tumor suppressor gene E-cadherin gene is frequently silenced in chronic lymphocytic leukemia (CLL) cells and results in wnt-pathway activation. We analyzed the role of histone epigenetic modifications in E-cadherin gene silencing. CLL specimens were treated with histone deacetylase inhibitor (HDACi) MS-275 and analyzed for E-cadherin expression with western blot and RT-PCR analysis. The downstream effects of HDACi treated leukemic cells were studied by analyzing the effect on wnt-pathway signaling. HDACi induced alterations in E-cadherin splicing were investigated by transcript specific real time PCR analysis. Treatment of CLL specimens with histone deacetylase inhibitors (HDACi) treatment resulted in an increase of the E-cadherin RNA transcript (5 to 119 fold increase, n=10) in eight out of ten CLL specimens indicating that this gene is down regulated by histone hypoacetylation in a majority of CLL specimens. The E-cadherin re-expression in CLL specimens was noted by western blot analysis as well. Besides epigenetic silencing another mechanism of E-cadherin inactivation is aberrant exon 11 splicing resulting in an alternatively spliced transcript that lacks exon 11 and is degraded by the non-sense mediated decay (NMD) pathway. Our chromatin immunoprecipitation experiments show that HDACi increased the acetylation of histones H3 and H4 in the E-cadherin promoter region. This also affected the E-cadherin exon 11 splicing pattern as HDACi treated CLL specimens preferentially expressed the correctly spliced transcript and not the exon 11 skipped aberrant transcript. The re-expressed E- cadherin binds to β-catenin with inhibition of the active wnt-beta-catenin pathway in these cells. This resulted in a down regulation of two wnt target genes, LEF and cyclinD1 and the wnt pathway reporter. The E-cadherin gene is epigenetically modified and hypoacetylated in CLL leukemic cells. Treatment of CLL specimens with HDACi MS-275 activates transcription from this silent

Dissociation of VE-PTP from VE-cadherin is required for leukocyte extravasation and for VEGF-induced vascular permeability in vivo

Science.gov (United States)

Broermann, Andre; Winderlich, Mark; Block, Helena; Frye, Maike; Rossaint, Jan; Zarbock, Alexander; Cagna, Giuseppe; Linnepe, Ruth; Schulte, Dörte; Nottebaum, Astrid Fee

2011-01-01

We have recently shown that vascular endothelial protein tyrosine phosphatase (VE-PTP), an endothelial membrane protein, associates with VE-cadherin and is required for optimal VE-cadherin function and endothelial cell contact integrity. The dissociation of VE-PTP from VE-cadherin is triggered by vascular endothelial growth factor (VEGF) and by the binding of leukocytes to endothelial cells in vitro, suggesting that this dissociation is a prerequisite for the destabilization of endothelial cell contacts. Here, we show that VE-cadherin/VE-PTP dissociation also occurs in vivo in response to LPS stimulation of the lung or systemic VEGF stimulation. To show that this dissociation is indeed necessary in vivo for leukocyte extravasation and VEGF-induced vascular permeability, we generated knock-in mice expressing the fusion proteins VE-cadherin-FK 506 binding protein and VE-PTP-FRB* under the control of the endogenous VE-cadherin promoter, thus replacing endogenous VE-cadherin. The additional domains in both fusion proteins allow the heterodimeric complex to be stabilized by a chemical compound (rapalog). We found that intravenous application of the rapalog strongly inhibited VEGF-induced (skin) and LPS-induced (lung) vascular permeability and inhibited neutrophil extravasation in the IL-1β inflamed cremaster and the LPS-inflamed lung. We conclude that the dissociation of VE-PTP from VE-cadherin is indeed required in vivo for the opening of endothelial cell contacts during induction of vascular permeability and leukocyte extravasation. PMID:22025303

A genome-wide screen identifies conserved protein hubs required for cadherin-mediated cell–cell adhesion

Science.gov (United States)

Toret, Christopher P.; D’Ambrosio, Michael V.; Vale, Ronald D.; Simon, Michael A.

2014-01-01

Cadherins and associated catenins provide an important structural interface between neighboring cells, the actin cytoskeleton, and intracellular signaling pathways in a variety of cell types throughout the Metazoa. However, the full inventory of the proteins and pathways required for cadherin-mediated adhesion has not been established. To this end, we completed a genome-wide (∼14,000 genes) ribonucleic acid interference (RNAi) screen that targeted Ca2+-dependent adhesion in DE-cadherin–expressing Drosophila melanogaster S2 cells in suspension culture. This novel screen eliminated Ca2+-independent cell–cell adhesion, integrin-based adhesion, cell spreading, and cell migration. We identified 17 interconnected regulatory hubs, based on protein functions and protein–protein interactions that regulate the levels of the core cadherin–catenin complex and coordinate cadherin-mediated cell–cell adhesion. Representative proteins from these hubs were analyzed further in Drosophila oogenesis, using targeted germline RNAi, and adhesion was analyzed in Madin–Darby canine kidney mammalian epithelial cell–cell adhesion. These experiments reveal roles for a diversity of cellular pathways that are required for cadherin function in Metazoa, including cytoskeleton organization, cell–substrate interactions, and nuclear and cytoplasmic signaling. PMID:24446484

Arf6 regulates EGF-induced internalization of E-cadherin in breast cancer cells.

Science.gov (United States)

Xu, Rui; Zhang, Yujie; Gu, Luo; Zheng, Jianchao; Cui, Jie; Dong, Jing; Du, Jun

2015-01-01

E-cadherin internalization facilitates dissolution of adherens junctions and promotes tumor cell epithelial-mesenchymal transition (EMT) and migration. Our previous results have shown that Arf6 exerts pro-migratory action in breast cancer cells after EGF stimulation. Despite the fact that EGF signaling stimulates EMT of breast cancer cells, the effect of Arf6 on internalization of E-cadherin of breast cancer cells under EGF treatment remains to be determined. Here, we showed that EGF dose-dependently stimulated E-cadherin internalization by MCF-7 cells with the maximal effect at 50 ng/ml. Meanwhile, EGF treatment markedly increased Arf6 activation. Arf6 was involved in complexes of E-cadherin, and more E-cadherin was pulled down with Arf6 when the activity of the latter was increased. Immunoblotting and immunofluorescence assays showed that transfection breast cancer cells with Arf6-T27N or Arf6 siRNA suppressed EGF-induced E-cadherin internalization. Taken together, our study demonstrated that Arf6 activation plays a potential role in EGF-induced E-cadherin internalization, providing new mechanism underlying the effect of Arf6 on promoting breast cancer cell metastasis.

E-cadherin Is Critical for Collective Sheet Migration and Is Regulated by the Chemokine CXCL12 Protein During Restitution*

Science.gov (United States)

Hwang, Soonyean; Zimmerman, Noah P.; Agle, Kimberle A.; Turner, Jerrold R.; Kumar, Suresh N.; Dwinell, Michael B.

2012-01-01

Chemokines and other immune mediators enhance epithelial barrier repair. The intestinal barrier is established by highly regulated cell-cell contacts between epithelial cells. The goal of these studies was to define the role for the chemokine CXCL12 in regulating E-cadherin during collective sheet migration during epithelial restitution. Mechanisms regulating E-cadherin were investigated using Caco2BBE and IEC-6 model epithelia. Genetic knockdown confirmed a critical role for E-cadherin in in vitro restitution and in vivo wound repair. During restitution, both CXCL12 and TGF-β1 tightened the monolayer by decreasing the paracellular space between migrating epithelial cells. However, CXCL12 differed from TGF-β1 by stimulating the significant increase in E-cadherin membrane localization during restitution. Chemokine-stimulated relocalization of E-cadherin was paralleled by an increase in barrier integrity of polarized epithelium during restitution. CXCL12 activation of its cognate receptor CXCR4 stimulated E-cadherin localization and monolayer tightening through Rho-associated protein kinase activation and F-actin reorganization. These data demonstrate a key role for E-cadherin in intestinal epithelial restitution. PMID:22549778

Water transport through the intestinal epithelial barrier under different osmotic conditions is dependent on LI-cadherin trans-interaction.

Science.gov (United States)

Weth, Agnes; Dippl, Carsten; Striedner, Yasmin; Tiemann-Boege, Irene; Vereshchaga, Yana; Golenhofen, Nikola; Bartelt-Kirbach, Britta; Baumgartner, Werner

2017-04-03

In the intestine water has to be reabsorbed from the chymus across the intestinal epithelium. The osmolarity within the lumen is subjected to high variations meaning that water transport often has to take place against osmotic gradients. It has been hypothesized that LI-cadherin is important in this process by keeping the intercellular cleft narrow facilitating the buildup of an osmotic gradient allowing water reabsorption. LI-cadherin is exceptional among the cadherin superfamily with respect to its localization along the lateral plasma membrane of epithelial cells being excluded from adherens junction. Furthermore it has 7 but not 5 extracellular cadherin repeats (EC1-EC7) and a small cytosolic domain. In this study we identified the peptide VAALD as an inhibitor of LI-cadherin trans-interaction by modeling the structure of LI-cadherin and comparison with the known adhesive interfaces of E-cadherin. This inhibitory peptide was used to measure LI-cadherin dependency of water transport through a monolayer of epithelial CACO2 cells under various osmotic conditions. If LI-cadherin trans-interaction was inhibited by use of the peptide, water transport from the luminal to the basolateral side was impaired and even reversed in the case of hypertonic conditions whereas no effect could be observed at isotonic conditions. These data are in line with a recently published model predicting LI-cadherin to keep the width of the lateral intercellular cleft small. In this narrow cleft a high osmolarity can be achieved due to ion pumps yielding a standing osmotic gradient allowing water absorption from the gut even if the faeces is highly hypertonic.

Prognostic potential of n-cadherin in oral squamous cell carcinoma via immunohistochemical methods

International Nuclear Information System (INIS)

Chandolia, B.; Arora, M.; Rajliwal, P.

2017-01-01

To assess the prognostic potential for N-cadherin in oral squamous cell carcinoma and oral epithelial dysplasia. Study Design: A cross-sectional study, analytical study. Place and Duration of Study: Maharishi Markandeshwar College of Dental Science Research (MMCDSR), Ambala, India, from 2011 to 2014. Methodology: Immunohistochemistry was used to observe the N-cadherin expression in 100 cases having epithelium with normal oral mucosa, oral epithelial dysplastic lesions and oral squamous cell carcinoma (OSCC). For statistical significance, SPSS 13.0 was used to calculate the data by Mann-Whitney and Kruskal-Wallis tests. Results: In OSCC, N-cadherin expression was more evident than in oral epithelial dysplasia followed by the normal oral epithelium that did not show any dysplastic changes (p=0.001). Conversely, N-cadherin expression was not significant among the histological grade of OSCC. Conclusion: N-cadherin can be used as a potential biomarker for early diagnosis of OSCC. However, the N-cadherin expression did not show any correlation with the histological grade of OSCC. (author)

Prognostic Potential of N-Cadherin in Oral Squamous Cell Carcinoma via Immunohistochemical Methods.

Science.gov (United States)

Chandolia, Betina; Rajliwal, Jai Parkash; Bajpai, Manas; Arora, Manika

2017-08-01

To assess the prognostic potential for N-cadherin in oral squamous cell carcinoma and oral epithelial dysplasia. Across-sectional study, analytical study. Maharishi Markandeshwar College of Dental Science Research (MMCDSR), Ambala, India, from 2011 to 2014. Immunohistochemistry was used to observe the N-cadherin expression in 100 cases having epithelium with normal oral mucosa, oral epithelial dysplastic lesions and oral squamous cell carcinoma (OSCC). For statistical significance, SPSS 13.0 was used to calculate the data by Mann-Whitney and Kruskal-Wallis tests. In OSCC, N-cadherin expression was more evident than in oral epithelial dysplasia followed by the normal oral epithelium that did not show any dysplastic changes (p=0.001). Conversely, N-cadherin expression was not significant among the histological grade of OSCC. N-cadherin can be used as a potential biomarker for early diagnosis of OSCC. However, the N-cadherin expression did not show any correlation with the histological grade of OSCC.

Phosphatidylinositol 5-phosphate 4-kinase type II beta is required for vitamin D receptor-dependent E-cadherin expression in SW480 cells

International Nuclear Information System (INIS)

Kouchi, Zen; Fujiwara, Yuki; Yamaguchi, Hideki; Nakamura, Yoshikazu; Fukami, Kiyoko

2011-01-01

Highlights: → We analyzed Phosphatidylinositol 5-phosphate kinase IIβ (PIPKIIβ) function in cancer. → PIPKIIβ is required for vitamin D receptor-mediated E-cadherin upregulation in SW480. → PIPKIIβ suppresses cellular motility through E-cadherin induction in SW480 cells. → Nuclear PIP 2 but not plasma membrane-localized PIP 2 mediates E-cadherin upregulation. -- Abstract: Numerous epidemiological data indicate that vitamin D receptor (VDR) signaling induced by its ligand or active metabolite 1α,25-dihydroxyvitamin D 3 (1α,25(OH) 2 D 3 ) has anti-cancer activity in several colon cancers. 1α,25(OH) 2 D 3 induces the epithelial differentiation of SW480 colon cancer cells expressing VDR (SW480-ADH) by upregulating E-cadherin expression; however, its precise mechanism remains unknown. We found that phosphatidylinositol-5-phosphate 4-kinase type II beta (PIPKIIβ) but not PIPKIIα is required for VDR-mediated E-cadherin induction in SW480-ADH cells. The syntenin-2 postsynaptic density protein/disc large/zona occludens (PDZ) domain and pleckstrin homology domain of phospholipase C-delta1 (PLCδ1 PHD) possess high affinity for phosphatidylinositol-4,5-bisphosphate (PI(4,5)P 2 ) mainly localized to the nucleus and plasma membrane, respectively. The expression of syntenin-2 PDZ but not PLCδ1 PHD inhibited 1α,25(OH) 2 D 3 -induced E-cadherin upregulation, suggesting that nuclear PI(4,5)P 2 production mediates E-cadherin expression through PIPKIIβ in a VDR-dependent manner. PIPKIIβ is also involved in the suppression of the cell motility induced by 1α,25(OH) 2 D 3 . These results indicate that PIPKIIβ-mediated PI(4,5)P 2 signaling is important for E-cadherin upregulation and inhibition of cellular motility induced by VDR activation.

Positive expression of LSD1 and negative expression of E-cadherin correlate with metastasis and poor prognosis of colon cancer.

Science.gov (United States)

Jie, Ding; Zhongmin, Zhang; Guoqing, Liao; Sheng, Liu; Yi, Zhang; Jing, Wen; Liang, Zeng

2013-06-01

The first identified lysine-specific demethylase, LSD1, plays an important role in the metastatic progression of several types of cancer. The aim of this study was to investigate LSD1, E-cadherin, and N-cadherin expression in colon cancer specimens and their clinical significance. The expression of LSD1, E-cadherin, and N-cadherin in colon cancer specimens was determined by immunohistochemistry, and the relationship between the expression of the respective molecules and clinicopathological characteristics was analyzed. The positive expression rates of LSD1, E-cadherin, and N-cadherin in colon cancer specimens were 66.7 % (72/108), 85.2 % (92/108), and 41.7 % (45/108), respectively. LSD1 was significantly more highly expressed in colon cancer specimens classified as high TNM stage lesions and with distant metastasis (P colon cancer specimens classified as high TNM stage lesions and with distant metastasis (P clinical and pathological characteristics (P > 0.05). Correlation analysis revealed that LSD1 expression was negatively correlated with E-cadherin expression (r s = -0.318, P = 0.001), but not evidently correlated with N-cadherin expression (r s = 0.182, P = 0.06). Colon cancer specimens with positive LSD1 expression and negative E-cadherin expression were correlated with significantly lower overall survival. LSD1 showed a significantly higher expression, in contrast to the significantly lower expression of E-cadherin, in colon cancer specimens classified as high TNM stage lesions and with distant metastasis. Positive expression of LSD1 and negative expression of E-cadherin may be predictors of a worse colon cancer prognosis.

Introduction of N-cadherin-binding motif to alginate hydrogels for controlled stem cell differentiation.

Science.gov (United States)

Lee, Jae Won; An, Hyoseok; Lee, Kuen Yong

2017-07-01

Control of stem cell fate and phenotype using biomimetic synthetic extracellular matrices (ECMs) is an important tissue engineering approach. Many studies have focused on improving cell-matrix interactions. However, proper control of cell-cell interactions using synthetic ECMs could be critical for tissue engineering, especially with undifferentiated stem cells. In this study, alginate hydrogels were modified with a peptide derived from the low-density lipoprotein receptor-related protein 5 (LRP5), which is known to bind to N-cadherin, as a cell-cell interaction motif. In vitro changes in the morphology and differentiation of mouse bone marrow stromal cells (D1 stem cells) cultured in LRP5-alginate hydrogels were investigated. LRP5-alginate gels successfully induced stem cell aggregation and enhanced chondrogenic differentiation of D1 stem cells, compared to RGD-alginate gels, at low cell density. This approach to tailoring synthetic biomimetic ECMs using cell-cell interaction motifs may be critical in tissue engineering approaches using stem cells. Copyright © 2017 Elsevier B.V. All rights reserved.

Connections between cadherin-catenin proteins, spindle misorientation, and cancer

DEFF Research Database (Denmark)

Shahbazi, Marta N; Perez-Moreno, Mirna

2015-01-01

Cadherin-catenin mediated adhesion is an important determinant of tissue architecture in multicellular organisms. Cancer progression and maintenance is frequently associated with loss of their expression or functional activity, which not only leads to decreased cell-cell adhesion, but also to enh......; and illustrates how alterations in cadherin-catenin levels or functional activity may render cells susceptible to transformation through the loss of their proliferation-differentiation balance....

Differential expression of liver-intestine cadherin in hepatocellular carcinoma and its clinical significance

Directory of Open Access Journals (Sweden)

QIU Shi

2013-01-01

Full Text Available ObjectiveTo investigate the expression of liver-intestine (LI-cadherin in hepatocellular carcinoma (HCC by tissue microarray and explore its relationship with pathologic features of HCC patients. MethodsSeventy primary HCC resection samples with different indexing and five primary normal tissue samples were assessed by tissue microarray and immunohistochemistry based on the SP method. The detected expression levels of LI-cadherin were compared to the clinic pathologic parameters of the tissue donors. ResultsLI-cadherin expression was detected in 39 (55.7% of the 70 primary HCC tissues, and none of the normal tissues. Positivity for LI-cadherin expression was significantly associated with lymph node metastasis and venous invasion (both P＜0.05, but no significant association was observed with age, sex, tumor grade, or metastasis (all P＞0.05. ConclusionLI-cadherin expression may be associated with HCC occurrence, tumor invasion, and metastasis. Future studies should assess the potential of LI-cadherin expression as a diagnostic biomarker or target of molecular therapy for HCC.

Surface engineered magnetic nanoparticles for specific immunotargeting of cadherin expressing cells

International Nuclear Information System (INIS)

Moros, Maria; Puertas, Sara; Saez, Berta; Grazú, Valeria; Delhaes, Flavien; Feracci, Helene; De la Fuente, Jesús M

2016-01-01

In spite of historic advances in cancer biology and recent development of sophisticated chemotherapeutics, the outlook for patients with advanced cancer is still grim. In this sense nanoparticles (NPs), through their unique physical properties, enable the development of new approaches for cancer diagnosis and treatment. Thus far the most used active targeting scheme involves NPs functionalization with antibodies specific to molecules overexpressed on cancer cell’s surface. Therefore, such active targeting relies on differences in NPs uptake kinetics rates between tumor and healthy cells. Many cancers of epithelial origin are associated with the inappropriate expression of non-epithelial cadherins (e.g. N-, P-, -11) with concomitant loss of E-cadherin. Such phenomenon named cadherin switching favors tumor development and metastasis via interactions of tumor cells with stromal components. That is why we optimized the oriented functionalization of fluorescently labelled magnetic NPs with a novel antibody specific for the extracellular domain of cadherin-11. The obtained Ab-NPs exhibited high specificity when incubated with two cell lines used as models of tumor and healthy cells. Thus, cadherin switching offers a great opportunity for the development of active targeting strategies aimed to improve the early detection and treatment of cancer. (paper)

Igf1r signaling is indispensable for preimplantation development and is activated via a novel function of E-cadherin.

Directory of Open Access Journals (Sweden)

Ivan Bedzhov

Full Text Available Insulin-like growth factor I receptor (Igf1r signaling controls proliferation, differentiation, growth, and cell survival in many tissues; and its deregulated activity is involved in tumorigenesis. Although important during fetal growth and postnatal life, a function for the Igf pathway during preimplantation development has not been described. We show that abrogating Igf1r signaling with specific inhibitors blocks trophectoderm formation and compromises embryo survival during murine blastocyst formation. In normal embryos total Igf1r is present throughout the membrane, whereas the activated form is found exclusively at cell contact sites, colocalizing with E-cadherin. Using genetic domain switching, we show a requirement for E-cadherin to maintain proper activation of Igf1r. Embryos expressing exclusively a cadherin chimera with N-cadherin extracellular and E-cadherin intracellular domains (NcEc fail to form a trophectoderm and cells die by apoptosis. In contrast, homozygous mutant embryos expressing a reverse-structured chimera (EcNc show trophectoderm survival and blastocoel cavitation, indicating a crucial and non-substitutable role of the E-cadherin ectodomain for these processes. Strikingly, blastocyst formation can be rescued in homozygous NcEc embryos by restoring Igf1r signaling, which enhances cell survival. Hence, perturbation of E-cadherin extracellular integrity, independent of its cell-adhesion function, blocked Igf1r signaling and induced cell death in the trophectoderm. Our results reveal an important and yet undiscovered function of Igf1r during preimplantation development mediated by a unique physical interaction between Igf1r and E-cadherin indispensable for proper receptor activation and anti-apoptotic signaling. We provide novel insights into how ligand-dependent Igf1r activity is additionally gated to sense developmental potential in utero and into a bifunctional role of adhesion molecules in contact formation and signaling.

Transforming growth factor β induces bone marrow mesenchymal stem cell migration via noncanonical signals and N-cadherin.

Science.gov (United States)

Dubon, Maria Jose; Yu, Jinyeong; Choi, Sanghyuk; Park, Ki-Sook

2018-01-01

Transforming growth factor-beta (TGF-β) induces the migration and mobilization of bone marrow-derived mesenchymal stem cells (BM-MSCs) to maintain bone homeostasis during bone remodeling and facilitate the repair of peripheral tissues. Although many studies have reported the mechanisms through which TGF-β mediates the migration of various types of cells, including cancer cells, the intrinsic cellular mechanisms underlying cellular migration, and mobilization of BM-MSCs mediated by TGF-β are unclear. In this study, we showed that TGF-β activated noncanonical signaling molecules, such as Akt, extracellular signal-regulated kinase 1/2 (ERK1/2), focal adhesion kinase (FAK), and p38, via TGF-β type I receptor in human BM-MSCs and murine BM-MSC-like ST2 cells. Inhibition of Rac1 by NSC23766 and Src by PP2 resulted in impaired TGF-β-mediated migration. These results suggested that the Smad-independent, noncanonical signals activated by TGF-β were necessary for migration. We also showed that N-cadherin-dependent intercellular interactions were required for TGF-β-mediated migration using functional inhibition of N-cadherin with EDTA treatment and a neutralizing antibody (GC-4 antibody) or siRNA-mediated knockdown of N-cadherin. However, N-cadherin knockdown did not affect the global activation of noncanonical signals in response to TGF-β. Therefore, these results suggested that the migration of BM-MSCs in response to TGF-β was mediated through N-cadherin and noncanonical TGF-β signals. © 2017 Wiley Periodicals, Inc.

Cadherin-8 expression, synaptic localization, and molecular control of neuronal form in prefrontal corticostriatal circuits.

Science.gov (United States)

Friedman, Lauren G; Riemslagh, Fréderike W; Sullivan, Josefa M; Mesias, Roxana; Williams, Frances M; Huntley, George W; Benson, Deanna L

2015-01-01

Neocortical interactions with the dorsal striatum support many motor and executive functions, and such underlying functional networks are particularly vulnerable to a variety of developmental, neurological, and psychiatric brain disorders, including autism spectrum disorders, Parkinson's disease, and Huntington's disease. Relatively little is known about the development of functional corticostriatal interactions, and in particular, virtually nothing is known of the molecular mechanisms that control generation of prefrontal cortex-striatal circuits. Here, we used regional and cellular in situ hybridization techniques coupled with neuronal tract tracing to show that Cadherin-8 (Cdh8), a homophilic adhesion protein encoded by a gene associated with autism spectrum disorders and learning disability susceptibility, is enriched within striatal projection neurons in the medial prefrontal cortex and in striatal medium spiny neurons forming the direct or indirect pathways. Developmental analysis of quantitative real-time polymerase chain reaction and western blot data show that Cdh8 expression peaks in the prefrontal cortex and striatum at P10, when cortical projections start to form synapses in the striatum. High-resolution immunoelectron microscopy shows that Cdh8 is concentrated at excitatory synapses in the dorsal striatum, and Cdh8 knockdown in cortical neurons impairs dendritic arborization and dendrite self-avoidance. Taken together, our findings indicate that Cdh8 delineates developing corticostriatal circuits where it is a strong candidate for regulating the generation of normal cortical projections, neuronal morphology, and corticostriatal synapses. © 2014 Wiley Periodicals, Inc.

The Cadherin Interaction as a Rate Limiting Step in Breast Cancer Metastasis to the Liver

National Research Council Canada - National Science Library

Chao, Yvonne

2008-01-01

.... Epithelial-cadherin (E-cadherin), the prototype classical cadherin present on the surface of most epithelial cells, has a cytoplasmic domain that anchors the cell adhesion molecule to the actin cytoskeleton via catenin-based complexes...

Upregulated N-cadherin expression is associated with poor prognosis in epithelial-derived solid tumours: A meta-analysis.

Science.gov (United States)

Luo, Yong; Yu, Ting; Zhang, Qiongwen; Fu, Qingyu; Hu, Yuzhu; Xiang, Mengmeng; Peng, Haoning; Zheng, Tianying; Lu, Li; Shi, Huashan

2018-04-01

N-cadherin is an important molecular in epithelial-mesenchymal transition (EMT) and has been reported to be associated with aggressive behaviours of tumours. However, prognostic value of N-cadherin in solid malignancies remains controversially. The Pubmed/MELINE and EMBASE databases were used for a comprehensive literature searching. Pooled risk ratio (RR) and hazard ratio (HR) with their corresponding 95% confidence intervals (CIs) were employed to quantify the prognostic role. Involving 36 studies with 5705 patients were performed to investigate relationships between N-cadherin upregulation and clinicopathological features, survival. Results suggested upregulated N-cadherin was associated with lymph node metastasis (RR = 1.16, 95% CI [1.00, 1.35]), higher histological grade (RR = 1.36, 95%CI [1.14, 1.62]), angiolymphatic invasion (RR = 1.19, 95% CI [1.06, 1.34]) and advanced clinical stage (RR = 1.32, 95% CI [1.06, 1.64]), while upregulated N-cadherin was apt to be associated with distant metastasis (RR = 1.43, 95% CI [0.99, 2.05]). Moreover, N-cadherin was correlated with poor prognosis of 3-year survival (HR = 1.78, 95% CI [1.51, 2.10]), 5-year survival (HR = 1.57, 95% CI [1.17, 2.10]) and overall survival (OS) (HR = 1.32, 95% CI [1.20, 1.44]). Subgroup analyses according to cancer types were also conducted for applying these conclusions to some tumours more properly. No publication bias was found except subgroup analysis of distant metastasis (P = .652 for Begg's test and 0.023 for Egger's test). Taken together, upregulation of N-cadherin is associated with more aggressive behaviours of epithelial-derived solid malignancies and can be regarded as a predictor of poor survival. © 2018 The Authors. European Journal of Clinical Investigation published by John Wiley & Sons Ltd on behalf of Stichting European Society for Clinical Investigation Journal Foundation.

VE-cadherin expression allows identification of a new class of hematopoietic stem cells within human embryonic liver.

Science.gov (United States)

Oberlin, Estelle; Fleury, Maud; Clay, Denis; Petit-Cocault, Laurence; Candelier, Jean-Jacques; Mennesson, Benoît; Jaffredo, Thierry; Souyri, Michèle

2010-11-25

Edification of the human hematopoietic system during development is characterized by the production of waves of hematopoietic cells separated in time, formed in distinct embryonic sites (ie, yolk sac, truncal arteries including the aorta, and placenta). The embryonic liver is a major hematopoietic organ wherein hematopoietic stem cells (HSCs) expand, and the future, adult-type, hematopoietic cell hierarchy becomes established. We report herein the identification of a new, transient, and rare cell population in the human embryonic liver, which coexpresses VE-cadherin, an endothelial marker, CD45, a pan-hematopoietic marker, and CD34, a common endothelial and hematopoietic marker. This population displays an outstanding self-renewal, proliferation, and differentiation potential, as detected by in vitro and in vivo hematopoietic assays compared with its VE-cadherin negative counterpart. Based on VE-cadherin expression, our data demonstrate the existence of 2 phenotypically and functionally separable populations of multipotent HSCs in the human embryo, the VE-cadherin(+) one being more primitive than the VE-cadherin(-) one, and shed a new light on the hierarchical organization of the embryonic liver HSC compartment.

Cell adhesion in Drosophila: versatility of cadherin and integrin complexes during development

OpenAIRE

Bulgakova, Natalia A.; Klapholz, Benjamin; Brown, Nicholas H.

2012-01-01

We highlight recent progress in understanding cadherin and integrin function in the model organism Drosophila. New functions for these adhesion receptors continue to be discovered in this system, emphasising the importance of cell adhesion within the developing organism and showing that the requirement for cell adhesion changes between cell types. New ways to control adhesion have been discovered, including controlling the expression and recruitment of adhesion components, their posttranslati...

VIP and VIP gene silencing modulation of differentiation marker N-cadherin and cell shape of corneal endothelium in human corneas ex vivo.

Science.gov (United States)

Koh, Shay-Whey M; Chandrasekara, Krish; Abbondandolo, Cara J; Coll, Timothy J; Rutzen, Allan R

2008-08-01

Vasoactive intestinal peptide (VIP) is expressed by corneal endothelial (CE) cells and is present in the aqueous humor, which bathes CE cells in vivo. This study demonstrated the role of CE cell VIP in maintaining the expression level of a CE differentiation marker, N-cadherin, and the hexagonal cell shape. To determine the most effective VIP concentration, bovine corneoscleral explants were treated with 0 (control) and 10(-12) to 10(-6) M VIP. Paired human corneas (nine donors) from an eye bank were used as control; the other corneas were treated with VIP. To silence endogenous VIP, paired fresh human donor corneas (from seven cadavers) were transduced with VIP shRNA or the control lentiviral particles and then bisected/quartered for quantitative analysis by semiquantitative RT-PCR (for mRNA) and Western blot analysis/immunocytochemistry (for protein), whereas alizarin red S staining revealed CE cell shape. VIP concentration dependently increased bovine CE cell N-cadherin mRNA levels, with the maximal effect observed between 10(-10) (1.47 +/- 0.06-fold; P = 0.002) and 10(-8) M VIP (1.48 +/- 0.18-fold; P = 0.012). VIP (10(-8) M) treatment increased N-cadherin protein levels in bovine and human CE cells to 1.98 +/- 0.28-fold (P = 0.005) and 1.17 +/- 0.10 (range, 0.91-1.87)-fold (P = 0.050) of their respective controls. VIP antagonist (SN)VIPhyb diminished the VIP effect. VIP silencing resulted in deterioration of the hexagonal cell shape and decreased levels of VIP protein and mRNA, N-cadherin (but not connexin-43) mRNA and protein, and the antiapoptotic Bcl-2 protein. Through its autocrine VIP, CE cells play an active role in maintaining the differentiated state and suppressing apoptosis in the corneal endothelium in situ.

The E-cadherin repressor slug and progression of human extrahepatic hilar cholangiocarcinoma

Directory of Open Access Journals (Sweden)

Wang Xin-sheng

2010-07-01

Full Text Available Abstract Objectives This study explored the expression and function of Slug in human extrahepatic hilar cholangiocarcinoma (EHC to identify its role in tumor progression. Methods The expression of Snail and Slug mRNA in 52 human tissue samples of EHC was investigated. The mRNA of Snail and Slug were quantified using reverse transcriptase-PCR, and correlations with E-cadherin expression and clinicopathological factors were investigated. We then investigated transfection of Slug cDNA in endogenous E-cadherin-positive human EHC FRH0201 cells, selectively induced the loss of E-cadherin protein expression, and then small interfering RNA (siRNA for inhibition of Slug expression in endogenous Slug-positive human EHC QBC939 cells, selectively induced the loss of Slug protein expression. A Boyden chamber transwell assay was used for invasion. Results Slug mRNA was overexpressed in 18 cases (34.6% of EHC compared with adjacent noncancerous tissue. E-Cadherin protein expression determined in the same 52 cases by immunohistochemistry was significantly down-regulated in those cases with Slug mRNA overexpression (P = 0.0001. The tumor and nontumor ratio of Slug mRNA was correlated with nodal metastasis(p = 0.0102, distant metastasis (p = 0.0001and Survival time(p = 0.0443. However, Snail mRNA correlated with neither E-cadherin expression nor tumor invasiveness. By inhibiting Slug expression by RNA interference, we found that reduced Slug levels upregulated E-cadherin and decreased invasion in QBC939 cell. When the QBC939 cells was infected with Slug cDNA,, significant E-cadherin was downregulated and increased invasion in QBC939 cell. Conclusions The results suggested that Slug expression plays an important role in both the regulation of E-cadherin expression and in the acquisition of invasive potential in human EHC. Slug is possibly a potential target for an antitumor therapy blocking the functions of invasion and metastasis in human EHCs.

A new role for E12/E47 in the repression of E-cadherin expression and epithelial-mesenchymal transitions

DEFF Research Database (Denmark)

Perez-Moreno, M A; Locascio, A; Rodrigo, I

2001-01-01

Down-regulation of E-cadherin expression is a determinant of tumor cell invasiveness, an event frequently associated with epithelial-mesenchymal transitions. Here we show that the mouse E12/E47 basic helix-loop-helix transcription factor (the E2A gene product) acts as a repressor of E-cadherin ex......Down-regulation of E-cadherin expression is a determinant of tumor cell invasiveness, an event frequently associated with epithelial-mesenchymal transitions. Here we show that the mouse E12/E47 basic helix-loop-helix transcription factor (the E2A gene product) acts as a repressor of E...

The ectodomain of cadherin-11 binds to erbB2 and stimulates Akt phosphorylation to promote cranial neural crest cell migration.

Directory of Open Access Journals (Sweden)

Ketan Mathavan

Full Text Available During development, a multi-potent group of cells known as the cranial neural crest (CNC migrate to form craniofacial structures. Proper migration of these cells requires proteolysis of cell adhesion molecules, such as cadherins. In Xenopus laevis, preventing extracellular cleavage of cadherin-11 impairs CNC migration. However, overexpression of the soluble cleavage product (EC1-3 is capable of rescuing this phenotype. The mechanism by which EC1-3 promotes CNC migration has not been investigated until now. Here we show that EC1-3 stimulates phosphorylation of Akt, a target of PI3K, in X.laevis CNC. Through immunoprecipitation experiments, we determined that EC1-3 interacts with all ErbB receptors, PDGFRα, and FGFR1. Of these receptors, only ErbB2 was able to produce an increase in Akt phosphorylation upon treatment with a recombinant EC1-3. This increase was abrogated by mubritinib, an inhibitor of ErbB2. We were able to recapitulate this decrease in Akt phosphorylation in vivo by knocking down ErbB2 in CNC cells. Knockdown of the receptor also significantly reduced CNC migration in vivo. We confirmed the importance of ErbB2 and ErbB receptor signaling in CNC migration using mubritinib and canertinib, respectively. Mubritinib and the PI3K inhibitor LY294002 significantly decreased cell migration while canertinib nearly prevented it altogether. These data show that ErbB2 and Akt are important for CNC migration and implicate other ErbB receptors and Akt-independent signaling pathways. Our findings provide the first example of a functional interaction between the extracellular domain of a type II classical cadherin and growth factor receptors.

Differences in E-Cadherin and Syndecan-1 Expression in Different Types of Ameloblastomas

Science.gov (United States)

López-Verdín, Sandra; Pereira-Prado, Vanesa

2018-01-01

Ameloblastomas are a group of benign, locally aggressive, recurrent tumors characterized by their slow and infiltrative growth. E-Cadherin and syndecan-1 are cell adhesion molecules related to the behavior of various tumors, including ameloblastomas. Ninety-nine ameloblastoma samples were studied; the expression of E-cadherin and syndecan-1 were evaluated by immunohistochemistry. E-Cadherin and epithelial syndecan-1 were more highly expressed in intraluminal/luminal unicystic ameloblastoma than in mural unicystic ameloblastoma and solid/multicystic ameloblastoma, whereas the stromal expression of syndecan-1 was higher in mural unicystic ameloblastoma and solid/multicystic ameloblastoma. Synchronicity was observed between E-cadherin and epithelial syndecan-1; the expression was correlated with intensity in all cases. There was a strong association between expression and tumor size and recurrence. The evaluation of the expression of E-cadherin and syndecan-1 are important for determining the potential aggressiveness of ameloblastoma variants. Future studies are required to understand how the expression of these markers is related to tumor aggressiveness.

A positive role of cadherin in Wnt/β-catenin signalling during epithelial-mesenchymal transition.

Directory of Open Access Journals (Sweden)

Sara Howard

Full Text Available The Wnt/β-catenin signalling pathway shares a key component, β-catenin, with the cadherin-based adhesion system. The signalling function of β-catenin is conferred by a soluble cytoplasmic pool that is unstable in the absence of a Wnt signal, whilst the adhesion function is based on a cadherin-bound, stable pool at the membrane. The cadherin complex is dynamic, allowing for cell-cell rearrangements such as epithelial-mesenchymal transition (EMT, where the complex turns over through internalisation. Potential interplay between the two pools remains poorly understood, but cadherins are generally considered negative regulators of Wnt signalling because they sequester cytoplasmic β-catenin. Here we explore how cellular changes at EMT affect the signalling capacity of β-catenin using two models of EMT: hepatocyte growth factor (HGF treatment of MDCK cells, and gastrulation in embryonic development. We show that EMT not only provides a pool of signalling-competent β-catenin following internalisation of cadherin, but also significantly facilitates activation of the Wnt pathway in response to both Wnt signals and exogenous β-catenin. We further demonstrate that availability of β-catenin in the cytoplasm does not necessarily correlate with Wnt/β-catenin pathway activity, since blocking endocytosis or depleting endogenous cadherin abolishes pathway activation despite the presence of β-catenin in the cytoplasm. Lastly we present data suggesting that cadherins are required for augmented activation of the Wnt/β-catenin pathway in vivo. This suggests that cadherins play a crucial role in β-catenin-dependent transcription.

Identification of E-cadherin signature motifs functioning as cleavage sites for Helicobacter pylori HtrA

Science.gov (United States)

Schmidt, Thomas P.; Perna, Anna M.; Fugmann, Tim; Böhm, Manja; Jan Hiss; Haller, Sarah; Götz, Camilla; Tegtmeyer, Nicole; Hoy, Benjamin; Rau, Tilman T.; Neri, Dario; Backert, Steffen; Schneider, Gisbert; Wessler, Silja

2016-03-01

The cell adhesion protein and tumour suppressor E-cadherin exhibits important functions in the prevention of gastric cancer. As a class-I carcinogen, Helicobacter pylori (H. pylori) has developed a unique strategy to interfere with E-cadherin functions. In previous studies, we have demonstrated that H. pylori secretes the protease high temperature requirement A (HtrA) which cleaves off the E-cadherin ectodomain (NTF) on epithelial cells. This opens cell-to-cell junctions, allowing bacterial transmigration across the polarised epithelium. Here, we investigated the molecular mechanism of the HtrA-E-cadherin interaction and identified E-cadherin cleavage sites for HtrA. Mass-spectrometry-based proteomics and Edman degradation revealed three signature motifs containing the [VITA]-[VITA]-x-x-D-[DN] sequence pattern, which were preferentially cleaved by HtrA. Based on these sites, we developed a substrate-derived peptide inhibitor that selectively bound and inhibited HtrA, thereby blocking transmigration of H. pylori. The discovery of HtrA-targeted signature sites might further explain why we detected a stable 90 kDa NTF fragment during H. pylori infection, but also additional E-cadherin fragments ranging from 105 kDa to 48 kDa in in vitro cleavage experiments. In conclusion, HtrA targets E-cadherin signature sites that are accessible in in vitro reactions, but might be partially masked on epithelial cells through functional homophilic E-cadherin interactions.

Identification of a claudin-4 and E-cadherin score to predict prognosis in breast cancer.

Science.gov (United States)

Szasz, Attila M; Nemeth, Zsuzsanna; Gyorffy, Balazs; Micsinai, Mariann; Krenacs, Tibor; Baranyai, Zsolt; Harsanyi, Laszlo; Kiss, Andras; Schaff, Zsuzsa; Tokes, Anna-Maria; Kulka, Janina

2011-12-01

The elevated expression of claudins (CLDN) and E-cadherin (CDH-1) was found to correlate with poor prognostic features. Our aim was to perform a comprehensive analysis to assess their potential to predict prognosis in breast cancer. The expression of CLDN-1, -3-5, -7, -8, -10, -15, -18, and E-cadherin at the mRNA level was evaluated in correlation with survival in datasets containing expression measurements of 1809 breast cancer patients. The breast cancer tissues of 197 patients were evaluated with tissue microarray technique and immunohistochemical method for CLDN-1-5, -7, and E-cadherin protein expression. An additional validation set of 387 patients was used to test the accuracy of the resulting prognostic score. Based on the bioinformatic screening of publicly-available datasets, the metagene of CLDN-3, -4, -7, and E-cadherin was shown to have the most powerful predictive power in the survival analyses. An immunohistochemical protein profile consisting of CLDN-2, -4, and E-cadherin was able to predict outcome in the most effective manner in the training set. Combining the overlapping members of the above two methods resulted in the claudin-4 and E-cadherin score (CURIO), which was able to accurately predict relapse-free survival in the validation cohort (P = 0.029). The multivariate analysis, including clinicopathological variables and the CURIO, showed that the latter kept its predictive power (P = 0.040). Furthermore, the CURIO was able to further refine prognosis, separating good versus poor prognosis subgroups in luminal A, luminal B, and triple-negative breast cancer intrinsic subtypes. In breast cancer, the CURIO provides additional prognostic information besides the routinely utilized diagnostic approaches and factors. © 2011 Japanese Cancer Association.

Mucinous Colorectal Adenocarcinoma: Influence of EGFR and E-Cadherin Expression on Clinicopathologic Features and Prognosis.

Science.gov (United States)

Foda, Abd AlRahman M; AbdelAziz, Azza; El-Hawary, Amira K; Hosni, Ali; Zalata, Khalid R; Gado, Asmaa I

2015-08-01

Previous studies have shown conflicting results on epidermal growth factor receptor (EGFR) and E-cadherin expression in colorectal carcinoma and their prognostic significance. To the best of our knowledge, this study is the first to investigate EGFR and E-cadherin expression, interrelation and relation to clinicopathologic, histologic parameters, and survival in rare colorectal mucinous adenocarcinoma (MA). In this study, we studied tumor tissue specimens from 150 patients with colorectal MA and nonmucinous adenocarcinoma (NMA). High-density manual tissue microarrays were constructed using modified mechanical pencil tips technique, and immunohistochemistry for EGFR and E-cadherin was performed. All relations were analyzed using established statistical methodologies. NMA expressed EGFR and E-cadherin in significantly higher rates with significant heterogenous pattern than MA. EGFR and E-cadherin positivity rates were significantly interrelated in both NMA and MA groups. In the NMA group, high EGFR expression was associated with old age, male sex, multiplicity of tumors, lack of mucinous component, and association with schistosomiasis. However, in the MA group, high EGFR expression was associated only with old age and MA subtype rather than signet ring carcinoma subtype. Conversely, high E-cadherin expression in MA cases was associated with old age, fungating tumor configuration, MA subtype, and negative intratumoral lymphocytic response. However, in the NMA cases, none of these factors was statistically significant. In a univariate analysis, neither EGFR nor E-cadherin expression showed a significant impact on disease-free or overall survival. Targeted therapy against EGFR and E-cadherin may not be useful in patients with MA. Neither EGFR nor E-cadherin is an independent prognostic factor in NMA or MA.

E-cadherin destabilization accounts for the pathogenicity of missense mutations in hereditary diffuse gastric cancer.

Directory of Open Access Journals (Sweden)

Joana Simões-Correia

Full Text Available E-cadherin is critical for the maintenance of tissue architecture due to its role in cell-cell adhesion. E-cadherin mutations are the genetic cause of Hereditary Diffuse Gastric Cancer (HDGC and missense mutations represent a clinical burden, due to the uncertainty of their pathogenic role. In vitro and in vivo, most mutations lead to loss-of-function, although the causal factor is unknown for the majority. We hypothesized that destabilization could account for the pathogenicity of E-cadherin missense mutations in HDGC, and tested our hypothesis using in silico and in vitro tools. FoldX algorithm was used to calculate the impact of each mutation in E-cadherin native-state stability, and the analysis was complemented with evolutionary conservation, by SIFT. Interestingly, HDGC patients harbouring germline E-cadherin destabilizing mutants present a younger age at diagnosis or death, suggesting that the loss of native-state stability of E-cadherin accounts for the disease phenotype. To elucidate the biological relevance of E-cadherin destabilization in HDGC, we investigated a group of newly identified HDGC-associated mutations (E185V, S232C and L583R, of which L583R is predicted to be destabilizing. We show that this mutation is not functional in vitro, exhibits shorter half-life and is unable to mature, due to premature proteasome-dependent degradation, a phenotype reverted by stabilization with the artificial mutation L583I (structurally tolerated. Herein we report E-cadherin structural models suitable to predict the impact of the majority of cancer-associated missense mutations and we show that E-cadherin destabilization leads to loss-of-function in vitro and increased pathogenicity in vivo.

E-cadherin expression and prognosis of head and neck squamous cell carcinoma: evidence from 19 published investigations

Directory of Open Access Journals (Sweden)

Ren X

2016-04-01

Full Text Available Xusheng Ren,1,2 Jianning Wang,2 Xuefen Lin,1,3 Xuxia Wang1,3 1Department of Oral and Maxillofacial Surgery, Stomatological Hospital of Shandong University, 2Department of Oral and Maxillofacial Surgery, Jinan Stomatological Hospital, 3Shandong Province Key Laboratory of Oral Tissue Regeneration, Stomatological Hospital of Shandong University, Jinan, Shandong Province, People’s Republic of China Objective: The objective of this study was to review the published literature and investigate whether E-cadherin gene is a prognostic factor in head and neck squamous cell carcinoma by conducting a meta-analysis.Methods: Studies were identified from the databases Embase, Medline, and Cochrane Library by using the keywords “E-cadherin gene” and “head and neck cancer”. Overall survival (OS and disease-free survival (DFS were the primary outcome measurements.Results: Our literature review identified 1,458 articles; 19 studies with a total number of 2,012 cases were eligible for inclusion in the meta-analysis. The hazard ratio (HR for OS of patients with decreased expression of E-cadherin gene was 0.57 (95% CI =0.37, 0.89; P=0.000. However, statistical heterogeneity was unacceptably high (I2=74.5%, P=0.000. After sensitivity analysis, heterogeneity became acceptable, and the effect measure was still significant (I2=7.0%; HR =0.52; 95% CI =0.40, 0.66; P=0.000. The HR for DFS was 0.53 (95% CI =0.42, 0.67; P=0.000.Conclusion: This meta-analysis showed clear evidence that high E-cadherin gene expression is a positive prognostic factor of head and neck squamous cell carcinoma, resulting in better OS and DFS. However, this conclusion must be interpreted with caution due to a few limitations. Keywords: E-cadherin gene, prognosis, head and neck squamous cell carcinoma, immunohistochemistry 

Prognostic Value of E-Cadherin and β-Catenin in Triple-Negative Breast Cancer.

Science.gov (United States)

Shen, Tiansheng; Zhang, Kui; Siegal, Gene P; Wei, Shi

2016-11-01

To analyze the expression of E-cadherin and β-catenin in triple-negative breast cancer (TNBC) to assess their prognostic significance. The expression of E-cadherin and β-catenin was examined semiquantitatively and correlated with other pathologic factors and survival outcomes. Of 72 consecutive TNBCs, 56% showed reduced membranous expression of E-cadherin or β-catenin, with a strong correlation to each other. Of the clinicopathologic factors analyzed, tumor size and nodal status were significantly associated with overall survival and disease-specific survival, while the latter remained an independent factor by multivariate analysis. Reduced E-cadherin and β-catenin were both significantly associated with a poor overall survival and disease-specific survival by univariate and multivariate analyses. E-cadherin and β-catenin expression provides discriminative prognostic power independent of conventional pathologic factors, thus further reinforcing the important role of cell adhesion molecules in the process of tumor metastasis, especially in TNBC. © American Society for Clinical Pathology, 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Mechanical coupling between transsynaptic N-cadherin adhesions and actin flow stabilizes dendritic spines

Science.gov (United States)

Chazeau, Anaël; Garcia, Mikael; Czöndör, Katalin; Perrais, David; Tessier, Béatrice; Giannone, Grégory; Thoumine, Olivier

2015-01-01

The morphology of neuronal dendritic spines is a critical indicator of synaptic function. It is regulated by several factors, including the intracellular actin/myosin cytoskeleton and transcellular N-cadherin adhesions. To examine the mechanical relationship between these molecular components, we performed quantitative live-imaging experiments in primary hippocampal neurons. We found that actin turnover and structural motility were lower in dendritic spines than in immature filopodia and increased upon expression of a nonadhesive N-cadherin mutant, resulting in an inverse relationship between spine motility and actin enrichment. Furthermore, the pharmacological stimulation of myosin II induced the rearward motion of actin structures in spines, showing that myosin II exerts tension on the actin network. Strikingly, the formation of stable, spine-like structures enriched in actin was induced at contacts between dendritic filopodia and N-cadherin–coated beads or micropatterns. Finally, computer simulations of actin dynamics mimicked various experimental conditions, pointing to the actin flow rate as an important parameter controlling actin enrichment in dendritic spines. Together these data demonstrate that a clutch-like mechanism between N-cadherin adhesions and the actin flow underlies the stabilization of dendritic filopodia into mature spines, a mechanism that may have important implications in synapse initiation, maturation, and plasticity in the developing brain. PMID:25568337

Heterocellular cadherin connections: coordinating adhesive cues in homeostasis and cancer [version 1; referees: 2 approved

Directory of Open Access Journals (Sweden)

Silvia Fontenete

2017-06-01

Full Text Available This short insight covers some of the recent topics relevant to the field of cadherin–catenin adhesion in mediating connections between different cell types, so-called heterotypic or heterocellular connections, in both homeostasis and cancer. These scientific discoveries are increasing our understanding of how multiple cells residing in complex tissues can be instructed by cadherin adhesion receptors to regulate tissue architecture and function and how these cadherin-mediated heterocellular connections spur tumor growth and the acquisition of malignant characteristics in tumor cells. Overall, the findings that have emerged over the past few years are elucidating the complexity of the functional roles of the cadherin–catenin complexes. Future exciting research lies ahead in order to understand the physical basis of these heterotypic interactions and their influence on the behavior of heterogeneous cellular populations as well as their roles in mediating phenotypic and genetic changes as cells evolve through complex environments during morphogenesis and cancer.

Thermo-chemotherapy Induced miR-218 upregulation inhibits the invasion of gastric cancer via targeting Gli2 and E-cadherin.

Science.gov (United States)

Ruan, Qiang; Fang, Zhi-Yuan; Cui, Shu-Zhong; Zhang, Xiang-Liang; Wu, Yin-Bing; Tang, Hong-Sheng; Tu, Yi-Nuo; Ding, Yan

2015-08-01

Thermo-chemotherapy has been proven to reduce the invasion capability of cancer cells. However, the molecular mechanism underlying this anti-invasion effect is still unclear. In this study, the role of thermo-chemotherapy in the inhibition of tumor invasion was studied. The results demonstrated that expression of miR-218 was downregulated in gastric cancer tissues, which had a positive correlation with tumor invasion and metastasis. In vitro thermo-chemotherapy increased miR-218 expression in SGC7901 cells and inhibited both proliferation and invasion of cancer cells. Gli2 was identified as a downstream target of miR-218, and its expression was negatively regulated by miR-218. The thermo-chemotherapy induced miR-218 upregulation was also accompanied by increasing of E-cadherin expression. In conclusion, the present study indicates that thermo-chemotherapy can effectively decrease the invasion capability of cancer cells and increase cell-cell adhesion. miR-218 and its downstream target Gli2, as well as E-cadherin, participate in the anti-invasion process.

High Glucose-Induced Reactive Oxygen Species Stimulates Human Mesenchymal Stem Cell Migration Through Snail and EZH2-Dependent E-Cadherin Repression

Directory of Open Access Journals (Sweden)

Ji Young Oh

2018-04-01

Full Text Available Background/Aims: Glucose plays an important role in stem cell fate determination and behaviors. However, it is still not known how glucose contributes to the precise molecular mechanisms responsible for stem cell migration. Thus, we investigate the effect of glucose on the regulation of the human umbilical cord blood-derived mesenchymal stem cell (hUCB-MSC migration, and analyze the mechanism accompanied by this effect. Methods: Western blot analysis, wound healing migration assays, immunoprecipitation, and chromatin immunoprecipitation assay were performed to investigate the effect of high glucose on hUCB-MSC migration. Additionally, hUCB-MSC transplantation was performed in the mouse excisional wound splinting model. Results: High concentration glucose (25 mM elicits hUCB-MSC migration compared to normal glucose and high glucose-pretreated hUCB-MSC transplantation into the wound sites in mice also accelerates skin wound repair. We therefore elucidated the detailed mechanisms how high glucose induces hUCB-MSC migration. We showed that high glucose regulates E-cadherin repression through increased Snail and EZH2 expressions. And, we found high glucose-induced reactive oxygen species (ROS promotes two signaling; JNK which regulates γ–secretase leading to the cleavage of Notch proteins and PI3K/Akt signaling which enhances GSK-3β phosphorylation. High glucose-mediated JNK/Notch pathway regulates the expression of EZH2, and PI3K/Akt/GSK-3β pathway stimulates Snail stabilization, respectively. High glucose enhances the formation of EZH2/Snail/HDAC1 complex in the nucleus, which in turn causes E-cadherin repression. Conclusion: This study reveals that high glucose-induced ROS stimulates the migration of hUCB-MSC through E-cadherin repression via Snail and EZH2 signaling pathways.

δ-Catenin Regulates Spine Architecture via Cadherin and PDZ-dependent Interactions*

Science.gov (United States)

Yuan, Li; Seong, Eunju; Beuscher, James L.; Arikkath, Jyothi

2015-01-01

The ability of neurons to maintain spine architecture and modulate it in response to synaptic activity is a crucial component of the cellular machinery that underlies information storage in pyramidal neurons of the hippocampus. Here we show a critical role for δ-catenin, a component of the cadherin-catenin cell adhesion complex, in regulating spine head width and length in pyramidal neurons of the hippocampus. The loss of Ctnnd2, the gene encoding δ-catenin, has been associated with the intellectual disability observed in the cri du chat syndrome, suggesting that the functional roles of δ-catenin are vital for neuronal integrity and higher order functions. We demonstrate that loss of δ-catenin in a mouse model or knockdown of δ-catenin in pyramidal neurons compromises spine head width and length, without altering spine dynamics. This is accompanied by a reduction in the levels of synaptic N-cadherin. The ability of δ-catenin to modulate spine architecture is critically dependent on its ability to interact with cadherin and PDZ domain-containing proteins. We propose that loss of δ-catenin during development perturbs synaptic architecture leading to developmental aberrations in neural circuit formation that contribute to the learning disabilities in a mouse model and humans with cri du chat syndrome. PMID:25724647

Down-regulated E-cadherin expression is associated with poor five-year overall survival in bone and soft tissue sarcoma: results of a meta-analysis.

Directory of Open Access Journals (Sweden)

Ning Wang

Full Text Available To conduct a meta-analysis to evaluate the prognostic role of E-cadherin expression in bone and soft tissue sarcomas.The PubMed, EMBASE, and Web of Science databases were searched using terms related to E-cadherin, sarcoma, and prognosis for all articles published in English before March 2014. Pooled effect was calculated from the available data to evaluate the association between negative E-cadherin expression and 5-year overall survival and tumor clinicopathological features in sarcoma patients. Pooled odds ratios (OR and risk ratios (RR with 95% confidence intervals (CI were calculated using a fixed-effects model.Eight studies met the selection criteria and reported on 812 subjects. A total of 496 subjects showed positive E-cadherin expression (59.9%. Negative E-cadherin expression in bone and soft tissue sarcomas was correlated with lower 5-year overall survival (OR = 3.831; 95% CI: 2.246-6.534, and was associated with higher clinical stage (RR = 1.446; 95% CI: 1.030-2.028 and with male sex (RR = 0.678; 95% CI: 0.493-0.933.In the E-cadherin negative group, 5-year overall survival was significantly worse than in the E-cadherin positive group. However, further studies are required to confirm these results.

Non-recessive Bt toxin resistance conferred by an intracellular cadherin mutation in field-selected populations of cotton bollworm.

Directory of Open Access Journals (Sweden)

Haonan Zhang

Full Text Available Transgenic crops producing Bacillus thuringiensis (Bt toxins have been planted widely to control insect pests, yet evolution of resistance by the pests can reduce the benefits of this approach. Recessive mutations in the extracellular domain of toxin-binding cadherin proteins that confer resistance to Bt toxin Cry1Ac by disrupting toxin binding have been reported previously in three major lepidopteran pests, including the cotton bollworm, Helicoverpa armigera. Here we report a novel allele from cotton bollworm with a deletion in the intracellular domain of cadherin that is genetically linked with non-recessive resistance to Cry1Ac. We discovered this allele in each of three field-selected populations we screened from northern China where Bt cotton producing Cry1Ac has been grown intensively. We expressed four types of cadherin alleles in heterologous cell cultures: susceptible, resistant with the intracellular domain mutation, and two complementary chimeric alleles with and without the mutation. Cells transfected with each of the four cadherin alleles bound Cry1Ac and were killed by Cry1Ac. However, relative to cells transfected with either the susceptible allele or the chimeric allele lacking the intracellular domain mutation, cells transfected with the resistant allele or the chimeric allele containing the intracellular domain mutation were less susceptible to Cry1Ac. These results suggest that the intracellular domain of cadherin is involved in post-binding events that affect toxicity of Cry1Ac. This evidence is consistent with the vital role of the intracellular region of cadherin proposed by the cell signaling model of the mode of action of Bt toxins. Considered together with previously reported data, the results suggest that both pore formation and cell signaling pathways contribute to the efficacy of Bt toxins.

Chlamydia trachomatis Infection Is Associated with E-Cadherin Promoter Methylation, Downregulation of E-Cadherin Expression, and Increased Expression of Fibronectin and α-SMA—Implications for Epithelial-Mesenchymal Transition

Directory of Open Access Journals (Sweden)

Jovana Rajić

2017-06-01

Full Text Available Chlamydia trachomatis (Ct can induce scarring disease of the ocular mucosa, known as trachoma, the most common infectious cause of blindness worldwide. We hypothesized that epithelial-mesenchymal transition (EMT contributes to the fibrotic process in trachomatous scarring. Infection of human conjunctival epithelial cells (HCjE with Ct activated signaling pathways involved in EMT induction, which was correlated with decreased expression of E-cadherin, guardian of the epithelial phenotype. In addition, Ct infection was associated with increased expression of two mesenchymal cell markers: fibronectin and α-SMA. The DNA methylation statuses of selected regions of E-cadherin, fibronectin, and α-SMA genes revealed that Ct infection was accompanied with changes in DNA methylation of the E-cadherin promoter, while the expression of the two mesenchymal markers was not related with this epigenetic event. Our data suggest that Ct infection of conjunctival epithelial cells induces EMT-like changes that go along with modification of the methylation profile of the E-cadherin promoter and could, as one of the earliest events, contribute to processes triggering conjunctival scarring.

Influence of intra-tumoral heterogeneity on the evaluation of BCL2, E-cadherin, EGFR, EMMPRIN, and Ki-67 expression in tissue microarrays from breast cancer.

Science.gov (United States)

Tramm, Trine; Kyndi, Marianne; Sørensen, Flemming B; Overgaard, Jens; Alsner, Jan

2018-01-01

The influence of intra-tumoral heterogeneity on the evaluation of immunohistochemical (IHC) biomarker expression may affect the analytical validity of new biomarkers substantially and hence compromise the clinical utility. The aim of this study was to examine the influence of intra-tumoral heterogeneity as well as inter-observer variability on the evaluation of various IHC markers with potential prognostic impact in breast cancer (BCL2, E-cadherin, EGFR, EMMPRIN and Ki-67). From each of 27 breast cancer patients, two tumor-containing paraffin blocks were chosen. Intra-tumoral heterogeneity was evaluated (1) within a single tumor-containing paraffin block ('intra-block agreement') by comparing information from a central, a peripheral tissue microarray (TMA) core and a whole slide section (WS), (2) between two different tumor-containing blocks from the same primary tumor ('inter-block agreement') by comparing information from TMA cores (central/peripheral) and WS. IHC markers on WS and TMA cores were evaluated by two observers independently, and agreements were estimated by Kappa statistics. For BCL2, E-cadherin and EGFR, an almost perfect intra- and inter-block agreement was found. EMMPRIN and Ki-67 showed a more heterogeneous expression with moderate to substantial intra-block agreements. For both stainings, there was a moderate inter-block agreement that improved slightly for EMMPRIN, when using WS instead of TMA cores. Inter-observer agreements were found to be almost perfect for BCL2, E-cadherin and EGFR (WS: κ > 0.82, TMAs: κ > 0.90), substantial for EMMPRIN (κ > 0.63), but only fair to moderate for Ki-67 (WS: κ = 0.54, TMAs: κ = 0.33). BCL2, E-cadherin and EGFR were found to be homogeneously expressed, whereas EMMPRIN and Ki-67 showed a more pronounced degree of intra-tumoral heterogeneity. The results emphasize the importance of securing the analytical validity of new biomarkers by examining the intra-tumoral heterogeneity of

E-Cadherin loss associated with EMT promotes radioresistance in human tumor cells

International Nuclear Information System (INIS)

Theys, Jan; Jutten, Barry; Habets, Roger; Paesmans, Kim; Groot, Arjan J.; Lambin, Philippe; Wouters, Brad G.; Lammering, Guido; Vooijs, Marc

2011-01-01

Background and purpose: Hypoxia is a hallmark of solid cancers and associated with metastases and treatment failure. During tumor progression epithelial cells often acquire mesenchymal features, a phenomenon known as epithelial-to-mesenchymal transition (EMT). Intratumoral hypoxia has been linked to EMT induction. We hypothesized that signals from the tumor microenvironment such as growth factors and tumor oxygenation collaborate to promote EMT and thereby contribute to radioresistance. Materials and methods: Gene expression changes under hypoxia were analyzed using microarray and validated by qRT-PCR. Conversion of epithelial phenotype upon hypoxic exposure, TGFβ addition or oncogene activation was investigated by Western blot and immunofluorescence. Cell survival following ionizing radiation was assayed using clonogenic survival. Results: Upon hypoxia, TGFβ addition or EGFRvIII expression, MCF7, A549 and NMuMG epithelial cells acquired a spindle shape and lost cell-cell contacts. Expression of epithelial markers such as E-cadherin decreased, whereas mesenchymal markers such as vimentin and N-cadherin increased. Combining hypoxia with TGFβ or EGFRvIII expression, lead to more rapid and pronounced EMT-like phenotype. Interestingly, E-cadherin expression and the mesenchymal appearance were reversible upon reoxygenation. Mesenchymal conversion and E-cadherin loss were associated with radioresistance. Conclusions: Our findings describe a mechanism by which the tumor microenvironment may contribute to tumor radioresistance via E-cadherin loss and EMT.

From genotypes to phenotypes: classification of the tumour profiles for different variants of the cadherin adhesion pathway

International Nuclear Information System (INIS)

Ramis-Conde, Ignacio; Drasdo, Dirk

2012-01-01

The E-cadherin adhesive profile expressed by a tumour is a characterization of the intracellular and intercellular protein interactions that control cell–cell adhesion. Within the intracellular proteins that determine the tumour adhesive profile, Src and PI3 are two essentials to initiate the formation of the E-cadherin adhesion complex. On the other hand, Src has also the capability of disrupting the β-catenin–E-cadherin complex and down-regulating cell–cell adhesion. In this paper, using a multi-scale mathematical model, we study the role of each of these proteins in the adhesive profile and invasive properties of the tumour. To do this, we create three versions of an intracellular model that explains the interplay between the proteins E-cadherin, β-catenin, Src and PI3; and we couple them to the strength of the cell–cell adhesion forces within an individual-cell-based model. The simulation results show how the tumour profile and its aggressive potential may change depending on the intrinsic characteristics of the protein pathways, and how these pathways may influence the early stages of cancer invasion. Our major findings may be summarized as follows. (1) Intermediate levels of Src synthesis rates generate the least invasive tumour phenotype. (2) Conclusions drawn from findings obtained from the intracellular molecular dynamics (here cadherin–catenin binding complexes) to the multi-cellular invasive potential of a tumour may be misleading or erroneous. The conclusions should be validated in a multi-cellular context on timescales relevant for population growth. (3) Monoclonal populations of more cohesive cells with otherwise equal properties tend to grow slower. (4) Less cohesive cells tend to outcompete more cohesive cells. (5) Less cohesive cells have a larger probability of invasion as migration forces can more easily outbalance cohesive forces. (paper)

From genotypes to phenotypes: classification of the tumour profiles for different variants of the cadherin adhesion pathway

Energy Technology Data Exchange (ETDEWEB)

Ramis-Conde, Ignacio [Facultad de Educación de Cuenca, Avenida de los Alfares 44, 16071 Universidad de Castilla la Mancha, Cuenca (Spain); Drasdo, Dirk [Institut National de Recherche en Informatique et en Automatique (INRIA), Rocquencourt/Paris (France)

2012-06-01

The E-cadherin adhesive profile expressed by a tumour is a characterization of the intracellular and intercellular protein interactions that control cell–cell adhesion. Within the intracellular proteins that determine the tumour adhesive profile, Src and PI3 are two essentials to initiate the formation of the E-cadherin adhesion complex. On the other hand, Src has also the capability of disrupting the β-catenin–E-cadherin complex and down-regulating cell–cell adhesion. In this paper, using a multi-scale mathematical model, we study the role of each of these proteins in the adhesive profile and invasive properties of the tumour. To do this, we create three versions of an intracellular model that explains the interplay between the proteins E-cadherin, β-catenin, Src and PI3; and we couple them to the strength of the cell–cell adhesion forces within an individual-cell-based model. The simulation results show how the tumour profile and its aggressive potential may change depending on the intrinsic characteristics of the protein pathways, and how these pathways may influence the early stages of cancer invasion. Our major findings may be summarized as follows. (1) Intermediate levels of Src synthesis rates generate the least invasive tumour phenotype. (2) Conclusions drawn from findings obtained from the intracellular molecular dynamics (here cadherin–catenin binding complexes) to the multi-cellular invasive potential of a tumour may be misleading or erroneous. The conclusions should be validated in a multi-cellular context on timescales relevant for population growth. (3) Monoclonal populations of more cohesive cells with otherwise equal properties tend to grow slower. (4) Less cohesive cells tend to outcompete more cohesive cells. (5) Less cohesive cells have a larger probability of invasion as migration forces can more easily outbalance cohesive forces. (paper)

E-cadherin expression increases cell proliferation by regulating energy metabolism through nuclear factor-κB in AGS cells.

Science.gov (United States)

Park, Song Yi; Shin, Jee-Hye; Kee, Sun-Ho

2017-09-01

β-Catenin is a central player in Wnt signaling, and activation of Wnt signaling is associated with cancer development. E-cadherin in complex with β-catenin mediates cell-cell adhesion, which suppresses β-catenin-dependent Wnt signaling. Recently, a tumor-suppressive role for E-cadherin has been reconsidered, as re-expression of E-cadherin was reported to enhance the metastatic potential of malignant tumors. To explore the role of E-cadherin, we established an E-cadherin-expressing cell line, EC96, from AGS cells that featured undetectable E-cadherin expression and a high level of Wnt signaling. In EC96 cells, E-cadherin re-expression enhanced cell proliferation, although Wnt signaling activity was reduced. Subsequent analysis revealed that nuclear factor-κB (NF-κB) activation and consequent c-myc expression might be involved in E-cadherin expression-mediated cell proliferation. To facilitate rapid proliferation, EC96 cells enhance glucose uptake and produce ATP using both mitochondria oxidative phosphorylation and glycolysis, whereas AGS cells use these mechanisms less efficiently. These events appeared to be mediated by NF-κB activation. Therefore, E-cadherin re-expression and subsequent induction of NF-κB signaling likely enhance energy production and cell proliferation. © 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

E-cadherin is transcriptionally activated via suppression of ZEB1 transcriptional repressor by small RNA-mediated gene silencing.

Directory of Open Access Journals (Sweden)

Minami Mazda

Full Text Available RNA activation has been reported to be induced by small interfering RNAs (siRNAs that act on the promoters of several genes containing E-cadherin. In this study, we present an alternative mechanism of E-cadherin activation in human PC-3 cells by siRNAs previously reported to possess perfect-complementary sequences to E-cadherin promoter. We found that activation of E-cadherin can be also induced via suppression of ZEB1, which is a transcriptional repressor of E-cadherin, by seed-dependent silencing mechanism of these siRNAs. The functional seed-complementary sites of the siRNAs were found in the coding region in addition to the 3' untranslated region of ZEB1 mRNA. Promoter analyses indicated that E-boxes, which are ZEB1-binding sites, in the upstream promoter region are indispensable for E-cadherin transcription by the siRNAs. Thus, the results caution against ignoring siRNA seed-dependent silencing effects in genome-wide transcriptional regulation. In addition, members of miR-302/372/373/520 family, which have the same seed sequences with one of the siRNAs containing perfect-complementarity to E-cadherin promoter, are also found to activate E-cadherin transcription. Thus, E-cadherin could be upregulated by the suppression of ZEB1 transcriptional repressor by miRNAs in vivo.

δ-Catenin Regulates Spine Architecture via Cadherin and PDZ-dependent Interactions.

Science.gov (United States)

Yuan, Li; Seong, Eunju; Beuscher, James L; Arikkath, Jyothi

2015-04-24

The ability of neurons to maintain spine architecture and modulate it in response to synaptic activity is a crucial component of the cellular machinery that underlies information storage in pyramidal neurons of the hippocampus. Here we show a critical role for δ-catenin, a component of the cadherin-catenin cell adhesion complex, in regulating spine head width and length in pyramidal neurons of the hippocampus. The loss of Ctnnd2, the gene encoding δ-catenin, has been associated with the intellectual disability observed in the cri du chat syndrome, suggesting that the functional roles of δ-catenin are vital for neuronal integrity and higher order functions. We demonstrate that loss of δ-catenin in a mouse model or knockdown of δ-catenin in pyramidal neurons compromises spine head width and length, without altering spine dynamics. This is accompanied by a reduction in the levels of synaptic N-cadherin. The ability of δ-catenin to modulate spine architecture is critically dependent on its ability to interact with cadherin and PDZ domain-containing proteins. We propose that loss of δ-catenin during development perturbs synaptic architecture leading to developmental aberrations in neural circuit formation that contribute to the learning disabilities in a mouse model and humans with cri du chat syndrome. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Preventing E-cadherin aberrant N-glycosylation at Asn-554 improves its critical function in gastric cancer

Science.gov (United States)

Carvalho, S; Catarino, TA; Dias, AM; Kato, M; Almeida, A; Hessling, B; Figueiredo, J; Gärtner, F; Sanches, JM; Ruppert, T; Miyoshi, E; Pierce, M; Carneiro, F; Kolarich, D; Seruca, R; Yamaguchi, Y; Taniguchi, N; Reis, CA; Pinho, SS

2016-01-01

E-cadherin is a central molecule in the process of gastric carcinogenesis and its posttranslational modifications by N-glycosylation have been described to induce a deleterious effect on cell adhesion associated with tumor cell invasion. However, the role that site-specific glycosylation of E-cadherin has in its defective function in gastric cancer cells needs to be determined. Using transgenic mice models and human clinical samples, we demonstrated that N-acetylglucosaminyltransferase V (GnT-V)-mediated glycosylation causes an abnormal pattern of E-cadherin expression in the gastric mucosa. In vitro models further indicated that, among the four potential N-glycosylation sites of E-cadherin, Asn-554 is the key site that is selectively modified with β1,6 GlcNAc-branched N-glycans catalyzed by GnT-V. This aberrant glycan modification on this specific asparagine site of E-cadherin was demonstrated to affect its critical functions in gastric cancer cells by affecting E-cadherin cellular localization, cis-dimer formation, molecular assembly and stability of the adherens junctions and cell–cell aggregation, which was further observed in human gastric carcinomas. Interestingly, manipulating this site-specific glycosylation, by preventing Asn-554 from receiving the deleterious branched structures, either by a mutation or by silencing GnT-V, resulted in a protective effect on E-cadherin, precluding its functional dysregulation and contributing to tumor suppression. PMID:26189796

Cadherins mediate sequential roles through a hierarchy of mechanisms in the developing mammillary body

Directory of Open Access Journals (Sweden)

Nora eSzabo

2015-03-01

Full Text Available Expression of intricate combinations of cadherins (a family of adhesive membrane proteins is common in the developing central nervous system. On this basis, a combinatorial cadherin code has long been proposed to underlie neuronal sorting and to be ultimately responsible for the layers, columns and nuclei of the brain. However, experimental proof of this particular function of cadherins has proven difficult to obtain and the question is still not clear. Alternatively, non-specific, non-combinatorial, purely quantitative adhesive differentials have been proposed to explain neuronal sorting in the brain. Do cadherin combinations underlie brain cytoarchitecture? We approached this question using as model a well-defined forebrain nucleus, the mammillary body (MBO, which shows strong, homogeneous expression of one single cadherin (Cdh11 and patterned, combinatorial expression of Cdh6, -8 and -10.We found that, besides the known combinatorial Cdh pattern, MBO cells are organized into a second, non-overlapping pattern grouping neurons with the same date of neurogenesis. Abolition of Cdh11 expression in the entire MBO during development disrupted the combination-based as well as the birthdate-based sorting. In utero RNAi experiments knocking down Cdh11 in MBO-fated migrating neurons at one specific age showed that Cdh11 expression is required for chronological entrance in the MBO.Our results suggest that neuronal sorting in the developing MBO is caused by adhesion-based, non-combinatorial mechanisms that keep neurons sorted according to birthdate information (possibly matching them to target neurons chronologically sorted in the same manner. Non-specific adhesion mechanisms would also prevent cadherin combinations from altering the birthdate-based sorting. Cadherin combinations would presumably act later to support specific synaptogenesis through specific axonal fasciculation and final target recognition.

p120 Catenin-Mediated Stabilization of E-Cadherin Is Essential for Primitive Endoderm Specification.

Directory of Open Access Journals (Sweden)

Tim Pieters

2016-08-01

Full Text Available E-cadherin-mediated cell-cell adhesion is critical for naive pluripotency of cultured mouse embryonic stem cells (mESCs. E-cadherin-depleted mESC fail to downregulate their pluripotency program and are unable to initiate lineage commitment. To further explore the roles of cell adhesion molecules during mESC differentiation, we focused on p120 catenin (p120ctn. Although one key function of p120ctn is to stabilize and regulate cadherin-mediated cell-cell adhesion, it has many additional functions, including regulation of transcription and Rho GTPase activity. Here, we investigated the role of mouse p120ctn in early embryogenesis, mESC pluripotency and early fate determination. In contrast to the E-cadherin-null phenotype, p120ctn-null mESCs remained pluripotent, but their in vitro differentiation was incomplete. In particular, they failed to form cystic embryoid bodies and showed defects in primitive endoderm formation. To pinpoint the underlying mechanism, we undertook a structure-function approach. Rescue of p120ctn-null mESCs with different p120ctn wild-type and mutant expression constructs revealed that the long N-terminal domain of p120ctn and its regulatory domain for RhoA were dispensable, whereas its armadillo domain and interaction with E-cadherin were crucial for primitive endoderm formation. We conclude that p120ctn is not only an adaptor and regulator of E-cadherin, but is also indispensable for proper lineage commitment.

Estrogen Deficiency Promotes Cerebral Aneurysm Rupture by Upregulation of Th17 Cells and Interleukin-17A Which Downregulates E-Cadherin.

Science.gov (United States)

Hoh, Brian L; Rojas, Kelley; Lin, Li; Fazal, Hanain Z; Hourani, Siham; Nowicki, Kamil W; Schneider, Matheus B; Hosaka, Koji

2018-04-13

Estrogen deficiency is associated with the development of cerebral aneurysms; however, the mechanism remains unknown. We explored the pathway of cerebral aneurysm development by investigating the potential link between estrogen deficiency and inflammatory factors. First, we established the role of interleukin-17 (IL-17)A. We performed a cytokine screen demonstrating that IL-17A is significantly expressed in mouse and human aneurysms ( P =0.03). Likewise, IL-17A inhibition was shown to prevent aneurysm formation by 42% ( P =0.02) and rupture by 34% ( P <0.05). Second, we found that estrogen deficiency upregulates T helper 17 cells and IL-17A and promotes aneurysm rupture. Estrogen-deficient mice had more ruptures than control mice (47% versus 7%; P =0.04). Estradiol supplementation or IL-17A inhibition decreased the number of ruptures in estrogen-deficient mice (estradiol 6% versus 37%; P =0.04; IL-17A inhibition 18% versus 47%; P =0.018). Third, we found that IL-17A-blockade protects against aneurysm formation and rupture by increased E-cadherin expression. IL-17-inhibited mice had increased E-cadherin expression ( P =0.003). E-cadherin inhibition reversed the protective effect of IL-17A inhibition and increased the rate of aneurysm formation (65% versus 28%; P =0.04) and rupture (12% versus 0%; P =0.22). However, E-cadherin inhibition alone does not significantly increase aneurysm formation in normal mice or in estrogen-deficient mice. In cell migration assays, E-cadherin inhibition promoted macrophage infiltration across endothelial cells ( P <0.05), which may be the mechanism for the estrogen deficiency/IL-17/E-cadherin aneurysm pathway. Our data suggest that estrogen deficiency promotes cerebral aneurysm rupture by upregulating IL-17A, which downregulates E-cadherin, encouraging macrophage infiltration in the aneurysm vessel wall. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Homophilic and Heterophilic Interactions of Type II Cadherins Identify Specificity Groups Underlying Cell-Adhesive Behavior

Directory of Open Access Journals (Sweden)

Julia Brasch

2018-05-01

Full Text Available Summary: Type II cadherins are cell-cell adhesion proteins critical for tissue patterning and neuronal targeting but whose molecular binding code remains poorly understood. Here, we delineate binding preferences for type II cadherin cell-adhesive regions, revealing extensive heterophilic interactions between specific pairs, in addition to homophilic interactions. Three distinct specificity groups emerge from our analysis with members that share highly similar heterophilic binding patterns and favor binding to one another. Structures of adhesive fragments from each specificity group confirm near-identical dimer topology conserved throughout the family, allowing interface residues whose conservation corresponds to specificity preferences to be identified. We show that targeted mutation of these residues converts binding preferences between specificity groups in biophysical and co-culture assays. Our results provide a detailed understanding of the type II cadherin interaction map and a basis for defining their role in tissue patterning and for the emerging importance of their heterophilic interactions in neural connectivity. : Type II cadherins are a family of vertebrate cell adhesion proteins expressed primarily in the CNS. Brasch et al. measure binding between adhesive fragments, revealing homophilic and extensive selective heterophilic binding with specificities that define groups of similar cadherins. Structures reveal common adhesive dimers, with residues governing cell-adhesive specificity. Keywords: cell adhesion, crystal structure, hemophilic specificity, heterophilic specificity, neural patterning, synaptic targeting, cadherin

E-cadherin promotes incorporation of mouse epiblast stem cells into normal development.

Directory of Open Access Journals (Sweden)

Satoshi Ohtsuka

Full Text Available Mouse epiblast stem cells (mEpiSCs are pluripotent stem cells derived from epiblasts of postimplantation mouse embryos. Their pluripotency is distinct from that of mouse embryonic stem cells (mESCs in several cell biological criteria. One of the distinctions is that mEpiSCs contribute either not at all or at much lower efficiency to chimeric embryos after blastocyst injection compared to mESCs. However, here we showed that mEpiSCs can be incorporated into normal development after blastocyst injection by forced expression of the E-cadherin transgene for 2 days in culture. Using this strategy, mEpiSCs gave rise to live-born chimeras from 5% of the manipulated blastocysts. There were no obvious signs of reprogramming of mEpiSCs toward the mESC-like state during the 2 days after induction of the E-cadherin transgene, suggesting that mEpiSCs possess latent ability to integrate into the normal developmental process as its origin, epiblasts.

Relationship among mismatch repair deficiency, CDX2 loss, p53 and E-cadherin in colon carcinoma and suitability of using a double panel of mismatch repair proteins by immunohistochemistry.

Science.gov (United States)

Sayar, Ilyas; Akbas, Emin Murat; Isik, Arda; Gokce, Aysun; Peker, Kemal; Demirtas, Levent; Gürbüzel, Mehmet

2015-09-01

Biomarkers such as mismatch repair proteins, CDX2, p53, and E-cadherin are blamed for colon cancers, but the relationships of these biomarkers with each other and with pathological risk factors in colon carcinoma are still not clear. The aim of this study was to evaluate the association of these biomarkers with each other by using immunohistochemical staining and to compare their expression with pathological risk factors for colonic adenocarcinoma. We also aimed to study the usability of a double panel of mismatch repair proteins. One hundred and eleven cases with colonic adenocarcinoma were examined. There was a statistically significant relationship between tumor histological differentiation and perineural invasion, vascular invasion, mismatch repair deficiency, p53, CDX2, and E-cadherin (p < 0.05). PMS2 and MSH6 loss covered 100% of cases with mismatch repair deficiency. Mismatch repair deficiency was correlated with CDX2 loss and E-cadherin expression (p < 0.05). It was also observed that cases with PMS2 loss covered all the cases with CDX2 loss. In conclusion, this double panel may be used instead of a quadruple panel for detecting mismatch repair deficiency. Association of CDX2 and PMS2 in the present study is necessary to conduct further genetic and pathological studies focusing on these two markers together.

Clinicopathologic Correlations of E-cadherin and Prrx-1 Expression Loss in Hepatocellular Carcinoma

Directory of Open Access Journals (Sweden)

Kijong Yi

2016-09-01

Full Text Available Background Developing predictive markers for hepatocellular carcinoma (HCC is important, because many patients experience recurrence and metastasis. Epithelial to mesenchymal transition (EMT is a developmental process that plays an important role during embryogenesis and also during cancer metastasis. Paired-related homeobox protein 1 (Prrx-1 is an EMT inducer that has recently been introduced, and its prognostic significance in HCC is largely unknown. Methods Tissue microarray was constructed using surgically resected primary HCCs from 244 cases. Immunohistochemical staining of E-cadherin and Prrx-1 was performed. The correlation between E-cadherin loss and Prrx-1 expression, as well as other clinicopathologic factors, was evaluated. Results E-cadherin expression was decreased in 96 cases (39.4%. Loss of E-cadherin correlated with a higher recurrence rate (p 40% were independent prognostic factors for shorter overall survival. Conclusions Prrx-1 was expressed in small portions of HCCs but not in normal livers. Additional studies with a large number of Prrx-1-positive cases are required to confirm the results of this study.

The transcription factor Slug represses E-cadherin expression and induces epithelial to mesenchymal transitions

DEFF Research Database (Denmark)

Bolós, Victoria; Peinado, Hector; Pérez-Moreno, Mirna A

2003-01-01

Transcriptional repression mechanisms have emerged as one of the crucial processes for the downregulation of E-cadherin expression during development and tumour progression. Recently, several E-cadherin transcriptional repressors have been characterized (Snail, E12/E47, ZEB-1 and SIP-1) and shown...

Cadherin adhesion, tissue tension, and noncanonical Wnt signaling regulate fibronectin matrix organization.

Science.gov (United States)

Dzamba, Bette J; Jakab, Karoly R; Marsden, Mungo; Schwartz, Martin A; DeSimone, Douglas W

2009-03-01

In this study we demonstrate that planar cell polarity signaling regulates morphogenesis in Xenopus embryos in part through the assembly of the fibronectin (FN) matrix. We outline a regulatory pathway that includes cadherin adhesion and signaling through Rac and Pak, culminating in actin reorganization, myosin contractility, and tissue tension, which, in turn, directs the correct spatiotemporal localization of FN into a fibrillar matrix. Increased mechanical tension promotes FN fibril assembly in the blastocoel roof (BCR), while reduced BCR tension inhibits matrix assembly. These data support a model for matrix assembly in tissues where cell-cell adhesions play an analogous role to the focal adhesions of cultured cells by transferring to integrins the tension required to direct FN fibril formation at cell surfaces.

Detachment-induced E-cadherin expression promotes 3D tumor spheroid formation but inhibits tumor formation and metastasis of lung cancer cells.

Science.gov (United States)

Powan, Phattrakorn; Luanpitpong, Sudjit; He, Xiaoqing; Rojanasakul, Yon; Chanvorachote, Pithi

2017-11-01

The epithelial-to-mesenchymal transition is proposed to be a key mechanism responsible for metastasis-related deaths. Similarly, cancer stem cells (CSCs) have been proposed to be a key driver of tumor metastasis. However, the link between the two events and their control mechanisms is unclear. We used a three-dimensional (3D) tumor spheroid assay and other CSC-indicating assays to investigate the role of E-cadherin in CSC regulation and its association to epithelial-to-mesenchymal transition in lung cancer cells. Ectopic overexpression and knockdown of E-cadherin were found to promote and retard, respectively, the formation of tumor spheroids in vitro but had opposite effects on tumor formation and metastasis in vivo in a xenograft mouse model. We explored the discrepancy between the in vitro and in vivo results and demonstrated, for the first time, that E-cadherin is required as a component of a major survival pathway under detachment conditions. Downregulation of E-cadherin increased the stemness of lung cancer cells but had an adverse effect on their survival, particularly on non-CSCs. Such downregulation also promoted anoikis resistance and invasiveness of lung cancer cells. These results suggest that anoikis assay could be used as an alternative method for in vitro assessment of CSCs that involves dysregulated adhesion proteins. Our data also suggest that agents that restore E-cadherin expression may be used as therapeutic agents for metastatic cancers. Copyright © 2017 the American Physiological Society.

Polymorphisms within the neuronal cadherin (CDH2) gene are associated with obsessive-compulsive disorder (OCD) in a South African cohort.

Science.gov (United States)

McGregor, N W; Lochner, C; Stein, D J; Hemmings, S M J

2016-02-01

OCD is characterised by recurrent obsessions and compulsions that result in severe distress and increased risk for comorbidity. Recently published findings have indicated that the neuronal cadherin gene (CDH2) plays a role in the development of canine OCD, and led us to investigate the human ortholog, CDH2, in a human OCD cohort. Seven CDH2 polymorphisms were selected and genotyped in a South African Caucasian cohort of 234 OCD patients and 180 healthy controls using TaqMan assays. Polymorphisms were analysed in a single-locus and haplotypic context. Of the seven polymorphisms, two reached statistical significance for OCD under additive and codominant models of inheritance (rs1120154 and rs12605662). CDH2 SNP, rs1120154, C-allele carriers were found to be significantly associated with lower risk to develop OCD compared to TT-homozygotes (OR = 0.49; 95% CI: 0.32-0.75; p OCD compared to TT-homozygotes (OR = 0.46; 95% CI: 0.30-0.71; p OCD diagnosis (*rs8087457-rs1148374: A-T). Polymorphisms within the CDH2 gene are associated with susceptibility to OCD in a South African cohort.

Differential expression of neural cell adhesion molecule and cadherins in pancreatic islets, glucagonomas, and insulinomas

DEFF Research Database (Denmark)

Møller, C J; Christgau, S; Williamson, M R

1992-01-01

The endocrine cells of the pancreas develop from the endoderm and yet display several characteristics of a neuronal phenotype. During embryonic life, ductal epithelial cells give rise to first the glugagon-producing cells (alpha-cells) and then cells that express insulin (beta-cells), somatostatin...... primary islet cells at all ages express unsialylated NCAM and E-cadherin, as do insulinomas, the glucagonomas express the polysialylated NCAM, which is characteristic for developing neurons. The glucagonomas also lose E-cadherin expression and instead express a cadherin which is similar to N...

Role Of Adhesion Molecules Vcam-1 And Ve-Cadherin In Endothelium Dysfunction Development At Hemorrhagic Fever With Renal Syndrome

Directory of Open Access Journals (Sweden)

А.А. Baygildina

2009-12-01

Full Text Available The research goal is to determine the changes in concentration of both sVCAM-1 and VE-cadherin in blood serum of patients suffered from hemorrhagic fever with renal syndrome (HFRS. 87 patients aged 15-65 were examined. Concentrations of both sVCAM-1 and VE- cadherin in blood serum by means of "Bender MedSystems" (Austria ELISA test were determined. It was shown that in both medium severe and severe forms of HFRS statistically the significant rise of sVCAM-1 concentration in blood with high indices in oliguric period took place. Complicated form was characterized by high indices of sVCAM-1 level in fever period, extremely decreasing in concentration in oliguric period and tendency to normalizing in clinical convalescence period. VE-cadherin level in blood was predominantly lower than control in all the observed groups with the exception of fever period in group with medium severe disease form. Negative correlation of normal intensity between adhesion molecules levels in blood was revealed. In conclusion it is necessary to point out that high VCAM-1 expression by endotheliocytes evidences the development of an adhesion form of endothelial dysfunction, low VE-cadherin production in a base for development of angiogenic form of endothelial dysfunction and changes in expression of these adhesion molecules that have adaptive metabolic response to macroorganism of HFRS pathogenic action

α-Catenin localization and sarcomere self-organization on N-cadherin adhesive patterns are myocyte contractility driven.

Directory of Open Access Journals (Sweden)

Anant Chopra

Full Text Available The N-cadherin (N-cad complex plays a crucial role in cardiac cell structure and function. Cadherins are adhesion proteins linking adjacent cardiac cells and, like integrin adhesions, are sensitive to force transmission. Forces through these adhesions are capable of eliciting structural and functional changes in myocytes. Compared to integrins, the mechanisms of force transduction through cadherins are less explored. α-catenin is a major component of the cadherin-catenin complex, thought to provide a link to the cell actin cytoskeleton. Using N-cad micropatterned substrates in an adhesion constrainment model, the results from this study show that α-catenin localizes to regions of highest internal stress in myocytes. This localization suggests that α-catenin acts as an adaptor protein associated with the cadherin mechanosensory apparatus, which is distinct from mechanosensing through integrins. Myosin inhibition in cells bound by integrins to fibronectin-coated patterns disrupts myofibiril organization, whereas on N-cad coated patterns, myosin inhibition leads to better organized myofibrils. This result indicates that the two adhesion systems provide independent mechanisms for regulating myocyte structural organization.

Intervention effects of ganoderma lucidum spores on epileptiform discharge hippocampal neurons and expression of neurotrophin-4 and N-cadherin.

Directory of Open Access Journals (Sweden)

Shu-Qiu Wang

Full Text Available Epilepsy can cause cerebral transient dysfunctions. Ganoderma lucidum spores (GLS, a traditional Chinese medicinal herb, has shown some antiepileptic effects in our previous studies. This was the first study of the effects of GLS on cultured primary hippocampal neurons, treated with Mg(2+ free medium. This in vitro model of epileptiform discharge hippocampal neurons allowed us to investigate the anti-epileptic effects and mechanism of GLS activity. Primary hippocampal neurons from <1 day old rats were cultured and their morphologies observed under fluorescence microscope. Neurons were confirmed by immunofluorescent staining of neuron specific enolase (NSE. Sterile method for GLS generation was investigated and serial dilutions of GLS were used to test the maximum non-toxic concentration of GLS on hippocampal neurons. The optimized concentration of GLS of 0.122 mg/ml was identified and used for subsequent analysis. Using the in vitro model, hippocampal neurons were divided into 4 groups for subsequent treatment i control, ii model (incubated with Mg(2+ free medium for 3 hours, iii GLS group I (incubated with Mg(2+ free medium containing GLS for 3 hours and replaced with normal medium and incubated for 6 hours and iv GLS group II (neurons incubated with Mg(2+ free medium for 3 hours then replaced with a normal medium containing GLS for 6 hours. Neurotrophin-4 and N-Cadherin protein expression were detected using Western blot. The results showed that the number of normal hippocampal neurons increased and the morphologies of hippocampal neurons were well preserved after GLS treatment. Furthermore, the expression of neurotrophin-4 was significantly increased while the expression of N-Cadherin was decreased in the GLS treated group compared with the model group. This data indicates that GLS may protect hippocampal neurons by promoting neurotrophin-4 expression and inhibiting N-Cadherin expression.

A Novel Tenebrio molitor Cadherin Is a Functional Receptor for Bacillus thuringiensis Cry3Aa Toxin*

OpenAIRE

Fabrick, Jeff; Oppert, Cris; Lorenzen, Marcé D.; Morris, Kaley; Oppert, Brenda; Jurat-Fuentes, Juan Luis

2009-01-01

Cry toxins produced by the bacterium Bacillus thuringiensis are effective biological insecticides. Cadherin-like proteins have been reported as functional Cry1A toxin receptors in Lepidoptera. Here we present data that demonstrate that a coleopteran cadherin is a functional Cry3Aa toxin receptor. The Cry3Aa receptor cadherin was cloned from Tenebrio molitor larval midgut mRNA, and the predicted protein, TmCad1, has domain structure and a putative toxin binding region similar to those in lepid...

Inhibition of Akt activity induces the mesenchymal-to-epithelial reverting transition with restoring E-cadherin expression in KB and KOSCC-25B oral squamous cell carcinoma cells

Directory of Open Access Journals (Sweden)

Hong Sam-Pyo

2009-02-01

, but did not affect phosphorylation of ERK, JNK, and p38 in KB and KOSCC-25B cells. Akt inhibition led to downregulation of Snail and Twist expression. In contrast, inhibition of Akt activity by PIA did not induce any changes in SIP-1/ZEB-2 expression. PIA treatment induced the expression of E-cadherin and β-catenin, reduce that of Vimentin, restored their epithelial morphology of a polygonal shape, and reduced tumor cell migration in KB and KOSCC-25B cells, which was the corresponding feature of MErT. Conclusion All of these findings suggest that Akt inhibition could induce the MErT through decreased NF-κB signaling and downregulation of Snail and Twist in OSCC cells. A strategy involving Akt inhibition might be a useful therapeutic tool in controlling cancer dissemination and metastasis in oral cancer patients.

E-cadherin Mediates the Preventive Effect of Vitamin D3 in Colitis-associated Carcinogenesis.

Science.gov (United States)

Xin, Yu; He, Longmei; Luan, Zijian; Lv, Hong; Yang, Hong; Zhou, Ying; Zhao, Xinhua; Zhou, Weixun; Yu, Songlin; Tan, Bei; Wang, Hongying; Qian, Jiaming

2017-09-01

Vitamin D3 is beneficial in ameliorating or preventing inflammation and carcinogenesis. Here, we evaluated if vitamin D3 has a preventive effect on colitis-associated carcinogenesis. Administration of azoxymethane (AOM), followed with dextran sulfate sodium (DSS), was used to simulate colitis-associated colon cancer in mice. The supplement of vitamin D3 at different dosages (15, 30, 60 IU·g·w), started before AOM or immediately after DSS treatment (post 60), was sustained to the end of the experiment. Dietary vitamin D3 significantly reduced the number of tumors and tumor burden in a dose-dependent manner. Of note, vitamin D3 in high doses showed significant preventive effects on carcinogenesis regardless of administration before or after AOM-DSS treatment. Cell proliferation decreased in vitamin D3 groups compared with the control group after inhibition of expression of β-catenin and its downstream target gene cyclin D1 in the colon. In vitro, vitamin D3 reduced the transcriptional activity and nuclear level of β-catenin, and it also increased E-cadherin expression and its binding affinity for β-catenin. Moreover, repression of E-cadherin was rescued by supplemental vitamin D3 in mouse colons. Taken together, our results indicate that vitamin D3 effectively suppressed colonic carcinogenesis in the AOM-DSS mouse model. Our findings further suggest that upregulation of E-cadherin contributes to the preventive effect of vitamin D3 on β-catenin activity.

Nanoscale E-Cadherin ligand patterns show threshold size for cellular adhesion and adherence junction formation

DEFF Research Database (Denmark)

Kristensen, Stine H; Pedersen, Gitte Albinus; Nejsum, Lene Niemann

2012-01-01

The role of ligand spatial distribution on the formation of cadherin mediated cell-cell contacts is studied utilizing nanopatterns of E-cadherin ligands. Protein patches ranging in size from 100 nm to 800 nm prepared by colloidal lithography critically influence adhesion, spreading and formation ...

ZEB1 overexpression associated with E-cadherin and microRNA-200 downregulation is characteristic of undifferentiated endometrial carcinoma.

Science.gov (United States)

Romero-Pérez, Laura; López-García, M Ángeles; Díaz-Martín, Juan; Biscuola, Michele; Castilla, M Ángeles; Tafe, Laura J; Garg, Karuna; Oliva, Esther; Matias-Guiu, Xavier; Soslow, Robert A; Palacios, José

2013-11-01

Undifferentiated endometrial carcinomas are very aggressive high-grade endometrial carcinomas that are frequently under-recognized. This study aimed to analyze the molecular alterations underlying the development of these endometrial carcinomas, focusing on those related to dedifferentiation. We assessed a series of 120 tumors: 57 grade 1 and 2 endometrioid endometrial carcinomas, 15 grade 3 endometrioid endometrial carcinomas, 27 endometrial serous carcinomas, and 21 undifferentiated endometrial carcinomas. We found a high frequency of DNA mismatch repair deficiency (38%) and moderate rate of p53 overexpression (∼33%) in undifferentiated carcinomas. In contrast to the characteristic endometrioid phenotype, there was a dramatic downregulation of E-cadherin expression in the undifferentiated subtype. Quantitative methylation studies dismissed CDH1 promoter hypermethylation as the mechanism responsible for this change in gene expression, while immunohistochemistry revealed that the E-cadherin repressor ZEB1 was frequently overexpressed (62%) in undifferentiated endometrial carcinomas. This finding was accompanied by a sharp downregulation in the expression of the miR-200 family of microRNAs, well-known targets of ZEB1. Furthermore, there was enhanced expression of epithelial-to-mesenchymal transition markers in undifferentiated endometrial carcinomas, such as N-cadherin, cytoplasmic p120, and osteonectin. In addition, HMGA2, a regulator of epithelial-to-mesenchymal transition that is expressed in aggressive endometrial tumors, such as endometrial serous carcinomas and carcinosarcomas, was expressed in >20% of undifferentiated carcinomas. These results suggest that ZEB1 overexpression, associated with E-cadherin and miR-200s downregulation, and the expression of mesenchymal markers might enhance the metastatic potential of undifferentiated endometrial carcinomas, leading to a poor prognosis. In addition, our observations suggest that the immnohistochemical analysis

Down-regulation of E-cadherin and catenins in human pituitary growth hormone-producing adenomas.

Science.gov (United States)

Sano, Toshiaki; Rong, Qian Zhi; Kagawa, Noriko; Yamada, Shozo

2004-01-01

Growth hormone (GH)-producing pituitary adenomas can be ultrastructurally divided into two major types: densely granulated and sparsely granulated. The latter type of adenoma characteristically exhibits globular accumulations of cytokeratin filaments known as fibrous bodies, which are immunohistochemically identifiable as juxtanuclear dot-like immunoreactivity. We hypothesize that the formation of fibrous body might be related to dysfunction of adhesion molecules, because of the functional relationship between intermediate filaments and the cadherin-catenin complex and frequent observation of loss of cohesiveness of the adenoma cells. Our recent immunohistochemical study showed that expression of E-cadherin and its undercoat proteins, alpha-, beta- and gamma-catenin, in GH cell adenomas with prominent fibrous bodies was significantly reduced compared with GH cell adenomas without fibrous bodies and the normal adenohypophysial cells. Although no mutation of exon 3 of the beta-catenin gene was found in any GH cell adenomas with fibrous bodies, methylation-specific polymerase chain reaction analysis revealed that the E-cadherin promoter region was methylated in 37.5% of these adenomas, two of which displayed total methylation, but not in GH cell adenomas without fibrous bodies. We conclude that the decreased expression of the E-cadherin-catenin complex and methylation of the E-cadherin gene promoter region are events associated with the formation of fibrous bodies in GH cell adenomas. It remains to be clarified to explain the mechanism by which down-regulation of adhesion molecules is involved in the abnormal assembly of intermediate filaments.

CMTM3 (CKLF-Like Marvel Transmembrane Domain 3) Mediates Angiogenesis by Regulating Cell Surface Availability of VE-Cadherin in Endothelial Adherens Junctions.

Science.gov (United States)

Chrifi, Ihsan; Louzao-Martinez, Laura; Brandt, Maarten; van Dijk, Christian G M; Burgisser, Petra; Zhu, Changbin; Kros, Johan M; Duncker, Dirk J; Cheng, Caroline

2017-06-01

Decrease in VE-cadherin adherens junctions reduces vascular stability, whereas disruption of adherens junctions is a requirement for neovessel sprouting during angiogenesis. Endocytosis plays a key role in regulating junctional strength by altering bioavailability of cell surface proteins, including VE-cadherin. Identification of new mediators of endothelial endocytosis could enhance our understanding of angiogenesis. Here, we assessed the function of CMTM3 (CKLF-like MARVEL transmembrane domain 3), which we have previously identified as highly expressed in Flk1 + endothelial progenitor cells during embryonic development. Using a 3-dimensional coculture of human umbilical vein endothelial cells-GFP (green fluorescent protein) and pericytes-RFP (red fluorescent protein), we demonstrated that siRNA-mediated CMTM3 silencing in human umbilical vein endothelial cells impairs angiogenesis. In vivo CMTM3 inhibition by morpholino injection in developing zebrafish larvae confirmed that CMTM3 expression is required for vascular sprouting. CMTM3 knockdown in human umbilical vein endothelial cells does not affect proliferation or migration. Intracellular staining demonstrated that CMTM3 colocalizes with early endosome markers EEA1 (early endosome marker 1) and Clathrin + vesicles and with cytosolic VE-cadherin in human umbilical vein endothelial cells. Adenovirus-mediated CMTM3 overexpression enhances endothelial endocytosis, shown by an increase in Clathrin + , EEA1 + , Rab11 + , Rab5 + , and Rab7 + vesicles. CMTM3 overexpression enhances, whereas CMTM3 knockdown decreases internalization of cell surface VE-cadherin in vitro. CMTM3 promotes loss of endothelial barrier function in thrombin-induced responses, shown by transendothelial electric resistance measurements in vitro. In this study, we have identified a new regulatory function for CMTM3 in angiogenesis. CMTM3 is involved in VE-cadherin turnover and is a regulator of the cell surface pool of VE-cadherin. Therefore, CMTM

Relation of glypican-3 and E-cadherin expressions to clinicopathological features and prognosis of mucinous and non-mucinous colorectal adenocarcinoma.

Science.gov (United States)

Foda, Abd Al-Rahman Mohammad; Mohammad, Mie Ali; Abdel-Aziz, Azza; El-Hawary, Amira Kamal

2015-06-01

Glypican-3 (GPC3) is a member of the membrane-bound heparin sulfate proteoglycans. E-cadherin is an adhesive receptor that is believed to act as a tumor suppressor gene. Many studies had investigated E-cadherin expressions in colorectal carcinoma (CRC) while only one study had investigated GPC3 expression in CRC. This study aims to investigate expression of GCP3 and E-cadherin in colorectal mucinous carcinoma (MA) and non-mucinous adenocarcinoma (NMA) using manual tissue microarray technique. Tumor tissue specimens are collected from 75 cases of MC and 75 cases of NMA who underwent radical surgery from Jan 2007 to Jan 2012 at the Gastroenterology Centre, Mansoura University, Egypt. Their clinicopathological parameters and survival data were revised and analyzed using established statistical methodologies. High-density manual tissue microarrays were constructed using modified mechanical pencil tip technique and immunohistochemistry for GPC3 and E-cadherin was done. NMA showed higher expression of GPC3 than MA with no statistically significant relation. NMA showed a significantly higher E-cadherin expression than MA. GPC3 and E-cadherin positivity rates were significantly interrelated in NMA, but not in MA, group. In NMA group, there was no significant relation between either GPC3 or E-cadherin expression and the clinicopathological features. In a univariate analysis, neither GPC3 nor E-cadherin expression showed a significant impact on disease-free survival (DFS) or overall survival (OS). GPC3 and E-cadherin expressions are not independent prognostic factors in CRC. However, expressions of both are significantly interrelated in NMA patients, suggesting an excellent interplay between both, in contrast to MA. Further molecular studies are needed to further explore the relationship between GCP3 and E-cadherin in colorectal carcinogenesis.

Expression of cadherin and NCAM in human small cell lung cancer cell lines and xenografts

DEFF Research Database (Denmark)

Rygaard, K; Møller, C; Bock, E

1992-01-01

examined. All tumours but one expressed both cadherin and NCAM. The tumours expressed one, two or rarely three cadherin bands, and different combinations of two major isoforms of NCAM with M(r)'s of approximately 190,000 and 135,000. Polysialylation of NCAM, a feature characteristic of NCAM during...

[Clinical significance of signal transduction and activators of transcription 3, E-cadherin and vimentin in colon cancer].

Science.gov (United States)

Zhang, Chao; Xu, Jian-Hua; Liu, Tao; Cui, Hao

2011-03-01

To evaluate the clinical significance of STAT3, E-cadherin and vimentin in colon cancer. Samples of colon cancer tissue and adjacent normal tissue were procured from 70 patients with colon cancer. The expressions of STAT3, E-cadherin and vimentin were detected by immunohistochemistry. Associations of clinicopathological characteristics and these three factors were evaluated. STAT3, E-cadherin, vimentin were positive in 74.3%,32.9%, and 78.6% in the colon cancer tissues, respectively, and were 15.7%, 82.9%, and 12.9% in normal colon mucosa tissues, respectively. They were correlated with tumor differentiation, depth of invasion, lymph node metastasis, and TNM staging(Pcolon cancer. The expressions of STAT3, E-cadherin and vimentin may serve as prognostic indicators for patients with colon cancer.

Reacquisition of E-cadherin expression in metastatic deposits of signet-ring cell carcinoma of the upper gastrointestinal system: a potential anchor for metastatic deposition.

Science.gov (United States)

Ma, Yihong R; Siegal, Gene P; Wei, Shi

2017-06-01

To examine the expression of E-cadherin in paired primary and metastatic signet-ring cell carcinomas (SRCC) of various organ systems in order to explore the potential role of the molecule in metastatic dissemination of this unique tumour type. Thirty-seven consecutive cases of SRCC from various organs with paired primary and metastatic tumorous tissue available were retrieved. The intensity of membranous E-cadherin expression was semiquantitatively scored on a scale of 0-3+. Reduced E-cadherin expression was a distinct feature of primary SRCC and was observed in 78% of primary tumours. Interestingly, the E-cadherin reduction was less frequently seen in metastatic SRCC when compared with their primary counterparts, and was only found in 57% of tumours in lymph node metastases or at distant sites of relapse. Furthermore, the mean score of E-cadherin expression of primary SRCC was significantly lower than that of their metastatic counterparts (2.3 vs 1.8; p=0.008). When divided by organ systems, the reacquisition of E-cadherin expression in the metastatic deposits was most remarkable in the SRCC of upper gastrointestinal tract origin (2.3 vs 1.4; p=0.003), whereas no significant difference was observed in other organ systems. While the reduction of E-cadherin in primary SRCC supports its pivotal role in epithelial-mesenchymal transition, a process crucial in tumour progression and metastatic dissemination, the re-expression of this molecule in metastatic SRCC cells implies a reversal to their epithelial phenotype (thus mesenchymal-epithelial transition) which, in turn, theoretically helps tumour cells to anchor and form cohesive metastatic deposits. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

T-Cadherin Expression in Melanoma Cells Stimulates Stromal Cell Recruitment and Invasion by Regulating the Expression of Chemokines, Integrins and Adhesion Molecules

International Nuclear Information System (INIS)

Rubina, Kseniya A.; Surkova, Ekaterina I.; Semina, Ekaterina V.; Sysoeva, Veronika Y.; Kalinina, Natalia I.; Poliakov, Alexei A.; Treshalina, Helena M.; Tkachuk, Vsevolod A.

2015-01-01

T-cadherin is a glycosyl-phosphatidylinositol (GPI) anchored member of the cadherin superfamily involved in the guidance of migrating cells. We have previously shown that in vivo T-cadherin overexpression leads to increased melanoma primary tumor growth due to the recruitment of mesenchymal stromal cells as well as the enhanced metastasis. Since tumor progression is highly dependent upon cell migration and invasion, the aim of the present study was to elucidate the mechanisms of T-cadherin participation in these processes. Herein we show that T-cadherin expression results in the increased invasive potential due to the upregulated expression of pro-oncogenic integrins, chemokines, adhesion molecules and extracellular matrix components. The detected increase in chemokine expression could be responsible for the stromal cell recruitment. At the same time our previous data demonstrated that T-cadherin expression inhibited neoangiogenesis in the primary tumors. We demonstrate that T-cadherin overexpression leads to the increase in the expression of anti-angiogenic molecules and reduction in pro-angiogenic factors. Thus, T-cadherin plays a dual role in melanoma growth and progression: T-cadherin expression results in anti-angiogenic effects in melanoma, however, this also stimulates transcription of genes responsible for migration and invasion of melanoma cells

T-Cadherin Expression in Melanoma Cells Stimulates Stromal Cell Recruitment and Invasion by Regulating the Expression of Chemokines, Integrins and Adhesion Molecules

Energy Technology Data Exchange (ETDEWEB)

Rubina, Kseniya A., E-mail: rkseniya@mail.ru; Surkova, Ekaterina I.; Semina, Ekaterina V.; Sysoeva, Veronika Y.; Kalinina, Natalia I. [Department of Biochemistry and Molecular Medicine, Faculty of Medicine, M.V. Lomonosov Moscow State University, Lomonosovsky av., 31/5, Moscow 119192 (Russian Federation); Poliakov, Alexei A. [Division of Developmental Neurobiology, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA (United Kingdom); Treshalina, Helena M. [Federal State Budgetary Scietific Institution «N.N. Blokhin Russian Cancer Research Center» (FSBSI “N.N.Blokhin RCRC”), Kashirskoe Shosse 24, Moscow 115478 (Russian Federation); Tkachuk, Vsevolod A. [Department of Biochemistry and Molecular Medicine, Faculty of Medicine, M.V. Lomonosov Moscow State University, Lomonosovsky av., 31/5, Moscow 119192 (Russian Federation)

2015-07-21

T-cadherin is a glycosyl-phosphatidylinositol (GPI) anchored member of the cadherin superfamily involved in the guidance of migrating cells. We have previously shown that in vivo T-cadherin overexpression leads to increased melanoma primary tumor growth due to the recruitment of mesenchymal stromal cells as well as the enhanced metastasis. Since tumor progression is highly dependent upon cell migration and invasion, the aim of the present study was to elucidate the mechanisms of T-cadherin participation in these processes. Herein we show that T-cadherin expression results in the increased invasive potential due to the upregulated expression of pro-oncogenic integrins, chemokines, adhesion molecules and extracellular matrix components. The detected increase in chemokine expression could be responsible for the stromal cell recruitment. At the same time our previous data demonstrated that T-cadherin expression inhibited neoangiogenesis in the primary tumors. We demonstrate that T-cadherin overexpression leads to the increase in the expression of anti-angiogenic molecules and reduction in pro-angiogenic factors. Thus, T-cadherin plays a dual role in melanoma growth and progression: T-cadherin expression results in anti-angiogenic effects in melanoma, however, this also stimulates transcription of genes responsible for migration and invasion of melanoma cells.

Nigral dopaminergic neuron replenishment in adult mice through VE-cadherin-expressing neural progenitor cells

Directory of Open Access Journals (Sweden)

Abir A Rahman

2017-01-01

Full Text Available The function of dopaminergic neurons in the substantia nigra is of central importance to the coordination of movement by the brain's basal ganglia circuitry. This is evidenced by the loss of these neurons, resulting in the cardinal motor deficits associated with Parkinson's disease. In order to fully understand the physiology of these key neurons and develop potential therapies for their loss, it is essential to determine if and how dopaminergic neurons are replenished in the adult brain. Recent work has presented evidence for adult neurogenesis of these neurons by Nestin+/Sox2– neural progenitor cells. We sought to further validate this finding and explore a potential atypical origin for these progenitor cells. Since neural progenitor cells have a proximal association with the vasculature of the brain and subsets of endothelial cells are Nestin+, we hypothesized that dopaminergic neural progenitors might share a common cell lineage. Therefore, we employed a VE-cadherin promoter-driven CREERT2:THlox/THlox transgenic mouse line to ablate the tyrosine hydroxylase gene from endothelial cells in adult animals. After 26 weeks, but not 13 weeks, following the genetic blockade of tyrosine hydroxylase expression in VE-cadherin+ cells, we observed a significant reduction in tyrosine hydroxylase+ neurons in the substantia nigra. The results from this genetic lineage tracing study suggest that dopaminergic neurons are replenished in adult mice by a VE-cadherin+ progenitor cell population potentially arising from an endothelial lineage.

Expression of E-cadherin and involucrin in leukoplakia and oral cancer: an immunocytochemical and immunohistochemical study

Directory of Open Access Journals (Sweden)

Alessandra Dutra da SILVA

2017-03-01

Full Text Available Abstract To assess the immunocytochemical and immunohistochemical correlation of adhesion (E-cadherin and cell differentiation (involucrin molecules in oral leukoplakia and oral squamous cell carcinoma. Cytological samples and biopsies were obtained from male and female patients aged over 30 years with oral leukoplakia (n = 30 and oral squamous cell carcinoma (n = 22. Cell scrapings and the biopsy were performed at the site of the lesion and histological slides were prepared for the immunocytochemical analysis of exfoliated oral mucosal cells and for the immunohistochemical analysis of biopsy tissues using E-cadherin and involucrin. Spearman’s correlation and kappa coefficients were used to assess the correlation and level of agreement between the techniques. Immunostaining for E-cadherin and involucrin by both techniques was similar in the superficial layers of the histological sections compared with cell scrapings. However, there was no statistical correlation and agreement regarding the immunocytochemical and immunohistochemical expression of E-cadherin and involucrin in oral leukoplakia (R = 0.01, p = 0.958 (Kappa = 0.017, p = 0.92 or in oral squamous cell carcinoma (R = 0.26, p = 0.206 (Kappa = 0.36, p = 0.07. The immunoexpression of E-cadherin and involucrin in tissues is consistent with the expression patterns observed in exfoliated oral mucosal cells, despite the lack of a statistically significant correlation. There is an association of the histopathological characteristics of leukoplakia with the expression E-cadherin and of the microscopic aspects of oral squamous cell carcinoma with immunohistochemical expression of involucrin.

E-cadherin and Vimentin as Predictors of Resistance to Preoperative Systemic Therapy in Patients with Advanced Breast Cancer

Directory of Open Access Journals (Sweden)

Sonar. S. Panigoro

2017-01-01

Full Text Available Loss of E-cadherin and increased vimentin expression are associated with epithelial-mesenchymal transition andcancer stemness which are responsible for treatment resistance. The study aims to evaluate the role of E-cadherin andvimentin as predictors of resistance to preoperative systemic therapy in patients with advanced breast cancer. This wasa cross-sectional analytical study in patients with stage III-IV breast cancer in Dharmais Cancer Hospital and dr. CiptoMangunkusumo National Hospital from July 2015 to April 2016. Patients had biopsy specimens embedded in paraffinblocks. Expressions of E-cadherin and vimentin proteins were done immunohistochemically. Treatment response wasevaluated histopathologically using Miller-Payne criteria on mastectomy specimens. A total of 65 patients were enrolled.Five patients with invasive lobular carcinoma were excluded. Thirty one had chemotherapy and 29 had hormonaltherapy. After treatment, 46 patients were eligible for mastectomy. E-cadherin and vimentin were positive in 28 (60.9%and 11 (20.3% of specimens. Twenty-three (50% patients showed no response. Treatment resistance were associatedwith type of therapy (OR=4.4; 95% CI=1.27-15.41; p=0.017 and vimentin expression (OR=6.75; 95% CI=1.27-30.02;p=0.016. Hormonal therapy (ORadj=6.26; 95%CI=1.59-24.6; p=0.009 and positive vimentin (ORadj=8.75; 95%CI=1.43-57.4; p=0.019 were independent predictors of treatment resistance. In conclusion, E-cadherin and vimentin can beused as predictors of resistance to preoperative systemic therapy in patients with advanced breast cancer. Keywords: breast cancer, cancer stemness, E-cadherin, preoperative therapy, vimentin.   Peran E-cadherin dan Vimentin sebagai Prediktor Resistensi Terapi Sistemik Preoperatif pada Pasien Kanker Payudara Stadium Lanjut Abstrak Hilangnya ekspresi E-cadherin dan meningkatnya ekspresi vimentin dihubungkan dengan epithelial-mesenchymaltransition dan cancer stemness yang bertanggungjawab terhadap

T-Cadherin Expression in Melanoma Cells Stimulates Stromal Cell Recruitment and Invasion by Regulating the Expression of Chemokines, Integrins and Adhesion Molecules

Directory of Open Access Journals (Sweden)

Kseniya A. Rubina

2015-07-01

Full Text Available T-cadherin is a glycosyl-phosphatidylinositol (GPI anchored member of the cadherin superfamily involved in the guidance of migrating cells. We have previously shown that in vivo T-cadherin overexpression leads to increased melanoma primary tumor growth due to the recruitment of mesenchymal stromal cells as well as the enhanced metastasis. Since tumor progression is highly dependent upon cell migration and invasion, the aim of the present study was to elucidate the mechanisms of T-cadherin participation in these processes. Herein we show that T-cadherin expression results in the increased invasive potential due to the upregulated expression of pro-oncogenic integrins, chemokines, adhesion molecules and extracellular matrix components. The detected increase in chemokine expression could be responsible for the stromal cell recruitment. At the same time our previous data demonstrated that T-cadherin expression inhibited neoangiogenesis in the primary tumors. We demonstrate molecules and reduction in pro-angiogenic factors. Thus, T-cadherin plays a dual role in melanoma growth and progression: T-cadherin expression results in anti-angiogenic effects in melanoma, however, this also stimulates transcription of genes responsible for migration and invasion of melanoma cells.

Expression of P-cadherin identifies prostate-specific-antigen-negative cells in epithelial tissues of male sexual accessory organs and in prostatic carcinomas. Implications for prostate cancer biology.

OpenAIRE

Soler, A. P.; Harner, G. D.; Knudsen, K. A.; McBrearty, F. X.; Grujic, E.; Salazar, H.; Han, A. C.; Keshgegian, A. A.

1997-01-01

Cadherins constitute a family of calcium-dependent cell-cell adhesion molecules the individual members of which are essential for the sorting of cells into tissues during development. In this study, we examined the expression of E-cadherin, N-cadherin, and P-cadherin in tissues obtained from radical prostatectomies. Epithelial cells of prostatic glands, ejaculatory ducts, and seminal vesicles expressed E-cadherin but not N-cadherin. P-cadherin was expressed in epithelial cells of the seminal ...

Cadherin complexes recruit mRNAs and RISC to regulate epithelial cell signaling.

Science.gov (United States)

Kourtidis, Antonis; Necela, Brian; Lin, Wan-Hsin; Lu, Ruifeng; Feathers, Ryan W; Asmann, Yan W; Thompson, E Aubrey; Anastasiadis, Panos Z

2017-10-02

Cumulative evidence demonstrates that most RNAs exhibit specific subcellular distribution. However, the mechanisms regulating this phenomenon and its functional consequences are still under investigation. Here, we reveal that cadherin complexes at the apical zonula adherens (ZA) of epithelial adherens junctions recruit the core components of the RNA-induced silencing complex (RISC) Ago2, GW182, and PABPC1, as well as a set of 522 messenger RNAs (mRNAs) and 28 mature microRNAs (miRNAs or miRs), via PLEKHA7. Top canonical pathways represented by these mRNAs include Wnt/β-catenin, TGF-β, and stem cell signaling. We specifically demonstrate the presence and silencing of MYC, JUN, and SOX2 mRNAs by miR-24 and miR-200c at the ZA. PLEKHA7 knockdown dissociates RISC from the ZA, decreases loading of the ZA-associated mRNAs and miRNAs to Ago2, and results in a corresponding increase of MYC, JUN, and SOX2 protein expression. The present work reveals a mechanism that directly links junction integrity to the silencing of a set of mRNAs that critically affect epithelial homeostasis. © 2017 Kourtidis et al.

Loss of TET1 facilitates DLD1 colon cancer cell migration via H3K27me3-mediated down-regulation of E-cadherin.

Science.gov (United States)

Zhou, Zhen; Zhang, Hong-Sheng; Liu, Yang; Zhang, Zhong-Guo; Du, Guang-Yuan; Li, Hu; Yu, Xiao-Ying; Huang, Ying-Hui

2018-02-01

Epigenetic modifications such as histone modifications and cytosine hydroxymethylation are linked to tumorigenesis. Loss of 5-hydroxymethylcytosine (5 hmC) by ten-eleven translocation 1 (TET1) down-regulation facilitates tumor initiation and development. However, the mechanisms by which loss of TET1 knockdown promotes malignancy development remains unclear. Here, we report that TET1 knockdown induced epithelial-mesenchymal transition (EMT) and increased cancer cell growth, migration, and invasion in DLD1 cells. Loss of TET1 increased EZH2 expression and reduced UTX-1 expression, thus increasing histone H3K27 tri-methylation causing repression of the target gene E-cadherin. Ectopic expression of the H3K27 demethylase UTX-1 or EZH2 depletion both impeded EZH2 binding caused a loss of H3K27 methylation at epithelial gene E-cadherin promoter, thereby suppressing EMT and tumor invasion in shTET1 cells. Conversely, UTX-1 depletion and ectopic expression of EZH2 enhanced EMT and tumor metastasis in DLD1 cells. These findings provide insight into the regulation of TET1 and E-cadherin and identify EZH2 as a critical mediator of E-cadherin repression and tumor progression. © 2017 Wiley Periodicals, Inc.

Involvement of microRNAs-MMPs-E-cadherin in the migration and invasion of gastric cancer cells infected with Helicobacter pylori.

Science.gov (United States)

Yang, Yongmei; Li, Xiaohui; Du, Jie; Yin, Youcong; Li, Yuanjian

2018-06-15

It has been found that Helicobacter pylori （H. pylori）is not only the main cause of gastric cancer, but also closely related to its metastasis. E-cadherin cleavage induced by matrix metalloproteinases (MMPs) plays an important role in the tumor metastasis. In the present study, we investigated the role of microRNAs-MMPs-E-cadherin in migration and invasion of gastric cancer cells treated with H. pylori. The results showed that H. pylori induced migration and invasion of SGC-7901 cells with a down-regulation of E-cadherin expression, which were abolished by MMPs knock down, E-cadherin overexpression, mimics of miR128 and miR148a. MiR128/miR148a inhibitors restored MMP-3/MMP-7 expression, down-regulated E-cadherin level, and accelerated cellular migration and invasion. This study suggests that H. pylori induces migration and invasion of gastric cancer cells through reduction of E-cadherin function by activation of MMP-3, - 7. The present results also suggest that the activated MMPs/E-cadherin pathway is related with down-regulation of miR128/miR148a in the human gastric cancer cells infected with H. pylori. Copyright © 2018. Published by Elsevier Inc.

Sialyl Lewis x expression in canine malignant mammary tumours: correlation with clinicopathological features and E-Cadherin expression

International Nuclear Information System (INIS)

Pinho, Salomé S; Matos, Augusto JF; Lopes, Célia; Marcos, Nuno T; Carvalheira, Júlio; Reis, Celso A; Gärtner, Fátima

2007-01-01

Sialyl Lewis x (sLe x ) antigen is a carbohydrate antigen that is considered not only a marker for cancer but also implicated functionally in the malignant behaviour of cancer cells. Overexpression of sLe x is associated with enhanced progression and metastases of many types of cancer including those of the mammary gland. Canine mammary tumours can invade and give rise to metastases via either lymphatic or blood vessels. E-Cadherin is specifically involved in epithelial cell-to-cell adhesion. In cancer, E-Cadherin underexpression is one of the alterations that characterizes the invasive phenotype and is considered an invasion/tumour suppressor gene. Partial or complete loss of E-Cadherin expression correlates with poor prognosis in canine malignant mammary cancer. The aim of this study was to analyse the sLe x expression in canine malignant mammary tumours and to evaluate if the presence of sLe x correlates with the expression of E-Cadherin and with clinicopathological features. Fifty-three cases of canine mammary carcinomas were analysed immunohistochemically using monoclonal antibodies against sLe x (IgM) and E-Cadherin (IgG). The clinicopathological data were then assessed to determine whether there was a correlation with sLe x tumour expression. Double labelled immunofluorescence staining was performed to analyse the combined expression of sLe x and E-Cadherin. sLe x expression was consistently demonstrated in all cases of canine mammary carcinomas with different levels of expression. We found a significant relationship between the levels of sLe x expression and the presence of lymph node metastases. We also demonstrated that when E-Cadherin expression was increased sLe x was reduced and vice-versa. The combined analysis of both adhesion molecules revealed an inverse relationship. In the present study we demonstrate the importance of sLe x in the malignant phenotype of canine malignant mammary tumours. Our results support the use of sLe x as a prognostic tumour

Simultaneous loss of E-cadherin and catenins in invasive lobular breast cancer and lobular carcinoma in situ

NARCIS (Netherlands)

de Leeuw, W. J.; Berx, G.; Vos, C. B.; Peterse, J. L.; van de Vijver, M. J.; Litvinov, S.; van Roy, F.; Cornelisse, C. J.; Cleton-Jansen, A. M.

1997-01-01

Loss of expression of the intercellular adhesion molecule E-cadherin frequently occurs in invasive lobular breast carcinomas as a result of mutational inactivation. Expression patterns of E-cadherin and the molecules comprising the cytoplasmic complex of adherens junctions, alpha-, beta- and

Direct regulation of E-cadherin by targeted histone methylation of TALE-SET fusion protein in cancer cells.

Science.gov (United States)

Cho, Hyun-Soo; Kang, Jeong Gu; Lee, Jae-Hye; Lee, Jeong-Ju; Jeon, Seong Kook; Ko, Jeong-Heon; Kim, Dae-Soo; Park, Kun-Hyang; Kim, Yong-Sam; Kim, Nam-Soon

2015-09-15

TALE-nuclease chimeras (TALENs) can bind to and cleave specific genomic loci and, are used to engineer gene knockouts and additions. Recently, instead of using the FokI domain, epigenetically active domains, such as TET1 and LSD1, have been combined with TAL effector domains to regulate targeted gene expression via DNA and histone demethylation. However, studies of histone methylation in the TALE system have not been performed. Therefore, in this study, we established a novel targeted regulation system with a TAL effector domain and a histone methylation domain. To construct a TALE-methylation fusion protein, we combined a TAL effector domain containing an E-Box region to act as a Snail binding site and the SET domain of EHMT 2 to allow for histone methylation. The constructed TALE-SET module (TSET) repressed the expression of E-cadherin via by increasing H3K9 dimethylation. Moreover, the cells that overexpressed TSET showed increased cell migration and invasion. This is the first phenotype-based study of targeted histone methylation by the TALE module, and this new system can be applied in new cancer therapies to reduce side effects.

CDH1 promoter hypermethylation and E-cadherin protein expression in infiltrating breast cancer

DEFF Research Database (Denmark)

Caldeira, José Roberto F; Prando, Erika C; Quevedo, Francisco C

2006-01-01

prognosis, and metastasis. Differential CpG island methylation in the promoter region of the CDH1 gene might be an alternative way for the loss of expression and function of E-cadherin, leading to loss of tissue integrity, an essential step in tumor progression. METHODS: The aim of our study was to assess...... not statistically significant, the levels of E-cadherin expression tended to diminish with the CDH1 promoter region methylation. In the group of 71 ductal cancinomas, most of the cases of showing CDH1 hypermethylation also presented reduced levels of expression of ER and PgR proteins, and a possible association......BACKGROUND: The E-cadherin gene (CDH1) maps, at chromosome 16q22.1, a region often associated with loss of heterozygosity (LOH) in human breast cancer. LOH at this site is thought to lead to loss of function of this tumor suppressor gene and was correlated with decreased disease-free survival, poor...

Asynchronous machines. Direct torque control; Machines asynchrones. Commande par controle direct de couple

Energy Technology Data Exchange (ETDEWEB)

Fornel, B. de [Institut National Polytechnique, 31 - Toulouse (France)

2006-05-15

The asynchronous machine, with its low cost and robustness, is today the most widely used motor to make speed variators. However, its main drawback is that the same current generates both the magnetic flux and the torque, and thus any torque variation creates a flux variation. Such a coupling gives to the asynchronous machine a nonlinear behaviour which makes its control much more complex. The direct self control (DSC) method has been developed to improve the low efficiency of the scalar control method and for the specific railway drive application. The direct torque control (DTC) method is derived from the DSC method but corresponds to other type of applications. The DSC and DTC algorithms for asynchronous motors are presented in this article: 1 - direct control of the stator flux (DSC): principle, flux control, torque control, switching frequency of the inverter, speed estimation; 2 - direct torque control (DTC): principle, electromagnetic torque derivative, signals shape and switching frequency, some results, DTC speed variator without speed sensor, DTC application to multi-machine multi-converter systems; 3 - conclusion. (J.S.)

Gene expression analysis of embryonic stem cells expressing VE-cadherin (CD144 during endothelial differentiation

Directory of Open Access Journals (Sweden)

Libermann Towia

2008-05-01

Full Text Available Abstract Background Endothelial differentiation occurs during normal vascular development in the developing embryo. This process is recapitulated in the adult when endothelial progenitor cells are generated in the bone marrow and can contribute to vascular repair or angiogenesis at sites of vascular injury or ischemia. The molecular mechanisms of endothelial differentiation remain incompletely understood. Novel approaches are needed to identify the factors that regulate endothelial differentiation. Methods Mouse embryonic stem (ES cells were used to further define the molecular mechanisms of endothelial differentiation. By flow cytometry a population of VEGF-R2 positive cells was identified as early as 2.5 days after differentiation of ES cells, and a subset of VEGF-R2+ cells, that were CD41 positive at 3.5 days. A separate population of VEGF-R2+ stem cells expressing the endothelial-specific marker CD144 (VE-cadherin was also identified at this same time point. Channels lined by VE-cadherin positive cells developed within the embryoid bodies (EBs formed by differentiating ES cells. VE-cadherin and CD41 expressing cells differentiate in close proximity to each other within the EBs, supporting the concept of a common origin for cells of hematopoietic and endothelial lineages. Results Microarray analysis of >45,000 transcripts was performed on RNA obtained from cells expressing VEGF-R2+, CD41+, and CD144+ and VEGF-R2-, CD41-, and CD144-. All microarray experiments were performed in duplicate using RNA obtained from independent experiments, for each subset of cells. Expression profiling confirmed the role of several genes involved in hematopoiesis, and identified several putative genes involved in endothelial differentiation. Conclusion The isolation of CD144+ cells during ES cell differentiation from embryoid bodies provides an excellent model system and method for identifying genes that are expressed during endothelial differentiation and that

PS1/γ-Secretase-Mediated Cadherin Cleavage Induces β-Catenin Nuclear Translocation and Osteogenic Differentiation of Human Bone Marrow Stromal Cells

Directory of Open Access Journals (Sweden)

Danielle C. Bonfim

2016-01-01

Full Text Available Bone marrow stromal cells (BMSCs are considered a promising tool for bone bioengineering. However, the mechanisms controlling osteoblastic commitment are still unclear. Osteogenic differentiation of BMSCs requires the activation of β-catenin signaling, classically known to be regulated by the canonical Wnt pathway. However, BMSCs treatment with canonical Wnts in vitro does not always result in osteogenic differentiation and evidence indicates that a more complex signaling pathway, involving cadherins, would be required to induce β-catenin signaling in these cells. Here we showed that Wnt3a alone did not induce TCF activation in BMSCs, maintaining the cells at a proliferative state. On the other hand, we verified that, upon BMSCs osteoinduction with dexamethasone, cadherins were cleaved by the PS1/γ-secretase complex at the plasma membrane, and this event was associated with an enhanced β-catenin translocation to the nucleus and signaling. When PS1/γ-secretase activity was inhibited, the osteogenic process was impaired. Altogether, we provide evidence that PS1/γ-secretase-mediated cadherin cleavage has as an important role in controlling β-catenin signaling during the onset of BMSCs osteogenic differentiation, as part of a complex signaling pathway responsible for cell fate decision. A comprehensive map of these pathways might contribute to the development of strategies to improve bone repair.

Ezrin and E-cadherin expression profile in cervical cytology: a prognostic marker for tumor progression in cervical cancer.

Science.gov (United States)

Zacapala-Gómez, Ana E; Navarro-Tito, Napoleón; Alarcón-Romero, Luz Del C; Ortuño-Pineda, Carlos; Illades-Aguiar, Berenice; Castañeda-Saucedo, Eduardo; Ortiz-Ortiz, Julio; Garibay-Cerdenares, Olga L; Jiménez-López, Marco A; Mendoza-Catalán, Miguel A

2018-03-27

Cervical cancer (CC) is the fourth cause of mortality by neoplasia in women worldwide. The use of immunomarkers is an alternative tool to complement currently used algorithms for detection of cancer, and to improve selection of therapeutic schemes. Aberrant expression of Ezrin and E-cadherin play an important role in tumor invasion. In this study we analyzed Ezrin and E-cadherin expression in liquid-based cervical cytology samples, and evaluated their potential use as prognostic immunomarkers. Immunocytochemical staining of Ezrin and E-cadherin was performed in cervical samples of 125 patients. The cytological or histological diagnostic was performed by Papanicolaou staining or H&E staining, respectively. HPV genotyping was determined using INNO-LIPA Genotyping Extra kit and the HPV physical status by in situ hybridization. Ezrin expression in HaCaT, HeLa and SiHa cell lines was determined by immunocytochemistry, immunofluorescence and Western blot. High Ezrin expression was observed in cervical cancer samples (70%), samples with multiple infection by HR-HPV (43%), and samples with integrated viral genome (47%). High Ezrin expression was associated with degree of SIL, viral genotype and physical status. In contrast, low E-cadherin expression was found in cervical cancer samples (95%), samples with multiple infection by HR-HPV/LR-HPV (87%) and integrated viral genome (72%). Low E-cadherin expression was associated with degree of SIL and viral genotype. Interestingly, Ezrin nuclear staining was associated with degree of SIL and viral genotype. High Ezrin expression, high percent of nuclear Ezrin and low E-cadherin expression behaved as risk factors for progression to HSIL and cervical cancer. Ezrin and E-cadherin expression profile in cervical cytology samples could be a potential prognostic marker, useful for identifying cervical lesions with a high-risk of progression to cervical cancer.

Down regulation of E-Cadherin (ECAD) - a predictor for occult metastatic disease in sentinel node biopsy of early squamous cell carcinomas of the oral cavity and oropharynx

International Nuclear Information System (INIS)

Huber, Gerhard F; Stoeckli, Sandro J; Züllig, Lena; Soltermann, Alex; Roessle, Matthias; Graf, Nicole; Haerle, Stephan K; Studer, Gabriela; Jochum, Wolfram; Moch, Holger

2011-01-01

Prognostic factors in predicting occult lymph node metastasis in patients with head and neck squamous-cell carcinoma (HNSCC) are necessary to improve the results of the sentinel lymph node procedure in this tumour type. The E-Cadherin glycoprotein is an intercellular adhesion molecule in epithelial cells, which plays an important role in establishing and maintaining intercellular connections. To determine the value of the molecular marker E-Cadherin in predicting regional metastatic disease. E-Cadherin expression in tumour tissue of 120 patients with HNSCC of the oral cavity and oropharynx were evaluated using the tissue microarray technique. 110 tumours were located in the oral cavity (91.7%; mostly tongue), 10 tumours in the oropharynx (8.3%). Intensity of E-Cadherin expression was quantified by the Intensity Reactivity Score (IRS). These results were correlated with the lymph node status of biopsied sentinel lymph nodes. Univariate and multivariate analysis was used to determine statistical significance. pT-stage, gender, tumour side and location did not correlate with lymph node metastasis. Differentiation grade (p = 0.018) and down regulation of E-Cadherin expression significantly correlate with positive lymph node status (p = 0.005) in univariate and multivariate analysis. These data suggest that loss of E-cadherin expression is associated with increased lymhogeneous metastasis of HNSCC. E-cadherin immunohistochemistry may be used as a predictor for lymph node metastasis in squamous cell carcinoma of the oral cavity and oropharynx. Level of evidence: 2b

Interaction of E-cadherin and PTEN regulates morphogenesis and growth arrest in human mammary epithelial cells

Energy Technology Data Exchange (ETDEWEB)

Fournier, Marcia V.; Fata, Jimmie E.; Martin, Katherine J.; Yaswen, Paul; Bissell, Mina J.

2009-06-03

PTEN is a dual function phosphatase with tumor suppressor function compromised in a wide spectrum of cancers. Because tissue polarity and architecture are crucial modulators of normal and malignant behavior, we postulated that PTEN may play a role in maintenance of tissue integrity. We used two non-malignant human mammary epithelial cell lines (HMECs) that form polarized, growth-arrested structures (acini) when cultured in 3-dimensional laminin-rich extracellular matrix gels (3D lrECM). As acini begin to form, PTEN accumulates in both the cytoplasm, and at cell-cell contacts where it colocalizes with E-cadherin/{beta}-catenin complex. Reduction of PTEN levels by shRNA in lrECM prevents formation of organized breast acini and disrupts growth arrest. Importantly, disruption of acinar polarity and cell-cell contact by E-cadherin function-blocking antibodies reduces endogenous PTEN protein levels and inhibits its accumulation at cell-cell contacts. Conversely, in SKBR3 breast cancer cells lacking endogenous E-cadherin expression, exogenous introduction of E-cadherin gene causes induction of PTEN expression and its accumulation at sites of cell interactions. These studies provide evidence that E-cadherin regulates both the PTEN protein levels and its recruitment to cell-cell junctions in 3D lrECM indicating a dynamic reciprocity between architectural integrity and the levels and localization of PTEN. This interaction thus appears to be a critical integrator of proliferative and morphogenetic signaling in breast epithelial cells.

Force via integrins but not E-cadherin decreases Oct3/4 expression in embryonic stem cells

Energy Technology Data Exchange (ETDEWEB)

Uda, Yuhei [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Department of Biomedical Engineering, Graduate School of Biomedical Engineering, Tohoku University, 6-6-01, Aramaki-aoba, Aoba-ward, Sendai City (Japan); Poh, Yeh-Chuin; Chowdhury, Farhan; Wu, Douglas C. [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Tanaka, Tetsuya S. [Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Sato, Masaaki [Department of Biomedical Engineering, Graduate School of Biomedical Engineering, Tohoku University, 6-6-01, Aramaki-aoba, Aoba-ward, Sendai City (Japan); Wang, Ning, E-mail: nwangrw@illinois.edu [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)

2011-11-18

Highlights: Black-Right-Pointing-Pointer Force via integrins or cadherins induces similar cell stiffening responses. Black-Right-Pointing-Pointer Force via integrins but not cadherins induces cell spreading. Black-Right-Pointing-Pointer Force via integrins but not cadherins induces differentiation of embryonic stem cells. -- Abstract: Increasing evidence suggests that mechanical factors play a critical role in fate decisions of stem cells. Recently we have demonstrated that a local force applied via Arg-Gly-Asp (RGD) peptides coated magnetic beads to mouse embryonic stem (ES) cells increases cell spreading and cell stiffness and decreases Oct3/4 (Pou5f1) gene expression. However, it is not clear whether the effects of the applied stress on these functions of ES cells can be extended to natural extracellular matrix proteins or cell-cell adhesion molecules. Here we show that a local cyclic shear force applied via fibronectin or laminin to integrin receptors increased cell spreading and stiffness, downregulated Oct3/4 gene expression, and decreased cell proliferation rate. In contrast, the same cyclic force applied via cell-cell adhesion molecule E-cadherin (Cdh1) had no effects on cell spreading, Oct3/4 gene expression, and the self-renewal of mouse ES cells, but induced significant cell stiffening. Our findings demonstrate that biological responses of ES cells to force applied via integrins are different from those to force via E-cadherin, suggesting that mechanical forces might play different roles in different force transduction pathways to shape early embryogenesis.

Dynamic interplay between adhesive and lateral E-cadherin dimers

DEFF Research Database (Denmark)

Klingelhöfer, Jörg; Laur, Oscar Y; Troyanovsky, Regina B

2002-01-01

M. The disappearance of adhesive dimers was counterbalanced by an increase in Trp156-dependent lateral dimers. Increasing the calcium concentration to a normal level rapidly restored the original balance between adhesive and lateral dimers. We also present evidence that E-cadherin dimers in vivo have a short lifetime...

Epithelial self-healing is recapitulated by a 3D biomimetic E-cadherin junction.

Science.gov (United States)

Cohen, Daniel J; Gloerich, Martijn; Nelson, W James

2016-12-20

Epithelial monolayers undergo self-healing when wounded. During healing, cells collectively migrate into the wound site, and the converging tissue fronts collide and form a stable interface. To heal, migrating tissues must form cell-cell adhesions and reorganize from the front-rear polarity characteristic of cell migration to the apical-basal polarity of an epithelium. However, identifying the "stop signal" that induces colliding tissues to cease migrating and heal remains an open question. Epithelial cells form integrin-based adhesions to the basal extracellular matrix (ECM) and E-cadherin-mediated cell-cell adhesions on the orthogonal, lateral surfaces between cells. Current biological tools have been unable to probe this multicellular 3D interface to determine the stop signal. We addressed this problem by developing a unique biointerface that mimicked the 3D organization of epithelial cell adhesions. This "minimal tissue mimic" (MTM) comprised a basal ECM substrate and a vertical surface coated with purified extracellular domain of E-cadherin, and was designed for collision with the healing edge of an epithelial monolayer. Three-dimensional imaging showed that adhesions formed between cells, and the E-cadherin-coated MTM resembled the morphology and dynamics of native epithelial cell-cell junctions and induced the same polarity transition that occurs during epithelial self-healing. These results indicate that E-cadherin presented in the proper 3D context constitutes a minimum essential stop signal to induce self-healing. That the Ecad:Fc MTM stably integrated into an epithelial tissue and reduced migration at the interface suggests that this biointerface is a complimentary approach to existing tissue-material interfaces.

Distribution of E-cadherin and ß-catenin in relation to cell maturation and cell extrusion in rat and mouse small intestines

DEFF Research Database (Denmark)

Larsson, Lars-Inge

2006-01-01

of programmed cell death (PCD) in mouse small intestinal epithelium. We have studied if this also occurs in the intact rodent small intestine. Our results confirm that extruded cells are negatie for E-cadherin. However, loss of the E-cadherin-interacting protein ß-cetenin preceded both extrusion and loss of E......-cadherin. Thus, all extruded cells as well as all cells in the process of extrusion lacked staining for ß-catenin. Moreover, almost 80% of all cells undergoing programmed cell death, as detected by the TUNEL reaction, lacked ß-catenin whereas over 70% of such cells were positive for E-cadherin. However, most...... ells lacking ß-catenin did not display signs of PCD as detected by the TUNEL method or by staining for active caspase-3. Therefore, these results suggest that loss of ß-catenin precedes the onset of programmed cell death, loss of E-cadherin and extrusion from the villi....

Glycoprotein 90K Promotes E-Cadherin Degradation in a Cell Density-Dependent Manner via Dissociation of E-Cadherin–p120-Catenin Complex

Directory of Open Access Journals (Sweden)

So-Yeon Park

2017-12-01

Full Text Available Glycoprotein 90K (also known as LGALS3BP or Mac-2BP is a tumor-associated protein, and high 90K levels are associated with poor prognosis in some cancers. To clarify the role of 90K as an indicator for poor prognosis and metastasis in epithelial cancers, the present study investigated the effect of 90K on an adherens junctional protein, E-cadherin, which is frequently absent or downregulated in human epithelial cancers. Treatment of certain cancer cells with 90K significantly reduced E-cadherin levels in a cell-population-dependent manner, and these cells showed decreases in cell adhesion and increases in invasive cell motility. Mechanistically, 90K-induced E-cadherin downregulation occurred via ubiquitination-mediated proteasomal degradation. 90K interacted with the E-cadherin–p120-catenin complex and induced its dissociation, altering the phosphorylation status of p120-catenin, whereas it did not associate with β-catenin. In subconfluent cells, 90K decreased membrane-localized p120-catenin and the membrane fraction of the p120-catenin. Particularly, 90K-induced E-cadherin downregulation was diminished in p120-catenin knocked-down cells. Taken together, 90K upregulation promotes the dissociation of the E-cadherin–p120-catenin complex, leading to E-cadherin proteasomal degradation, and thereby destabilizing adherens junctions in less confluent tumor cells. Our results provide a potential mechanism to explain the poor prognosis of cancer patients with high serum 90K levels.

A Novel Tenebrio molitor Cadherin Is a Functional Receptor for Bacillus thuringiensis Cry3Aa Toxin*

Science.gov (United States)

Fabrick, Jeff; Oppert, Cris; Lorenzen, Marcé D.; Morris, Kaley; Oppert, Brenda; Jurat-Fuentes, Juan Luis

2009-01-01

Cry toxins produced by the bacterium Bacillus thuringiensis are effective biological insecticides. Cadherin-like proteins have been reported as functional Cry1A toxin receptors in Lepidoptera. Here we present data that demonstrate that a coleopteran cadherin is a functional Cry3Aa toxin receptor. The Cry3Aa receptor cadherin was cloned from Tenebrio molitor larval midgut mRNA, and the predicted protein, TmCad1, has domain structure and a putative toxin binding region similar to those in lepidopteran cadherin B. thuringiensis receptors. A peptide containing the putative toxin binding region from TmCad1 bound specifically to Cry3Aa and promoted the formation of Cry3Aa toxin oligomers, proposed to be mediators of toxicity in lepidopterans. Injection of TmCad1-specific double-stranded RNA into T. molitor larvae resulted in knockdown of the TmCad1 transcript and conferred resistance to Cry3Aa toxicity. These data demonstrate the functional role of TmCad1 as a Cry3Aa receptor in T. molitor and reveal similarities between the mode of action of Cry toxins in Lepidoptera and Coleoptera. PMID:19416969

Expression analysis of E-cadherin, Slug and GSK3β in invasive ductal carcinoma of breast

International Nuclear Information System (INIS)

Prasad, Chandra P; Rath, Gayatri; Mathur, Sandeep; Bhatnagar, Dinesh; Parshad, Rajinder; Ralhan, Ranju

2009-01-01

Cancer progression is linked to a partially dedifferentiated epithelial cell phenotype. The signaling pathways Wnt, Hedgehog, TGF-β and Notch have been implicated in experimental and developmental epithelial mesenchymal transition (EMT). Recent findings from our laboratory confirm that active Wnt/β-catenin signaling is critically involved in invasive ductal carcinomas (IDCs) of breast. In the current study, we analyzed the expression patterns and relationships between the key Wnt/β-catenin signaling components- E-cadherin, Slug and GSK3β in IDCs of breast. Of the 98 IDCs analyzed, 53 (54%) showed loss/or reduced membranous staining of E-cadherin in tumor cells. Nuclear accumulation of Slug was observed in 33 (34%) IDCs examined. Loss or reduced level of cytoplasmic GSK3β expression was observed in 52/98 (53%) cases; while 34/98 (35%) tumors showed nuclear accumulation of GSK3β. Statistical analysis revealed associations of nuclear Slug expression with loss of membranous E-cadherin (p = 0.001); nuclear β-catenin (p = 0.001), and cytoplasmic β-catenin (p = 0.005), suggesting Slug mediated E-cadherin suppression via the activation of Wnt/β-catenin signaling pathway in IDCs. Our study also demonstrated significant correlation between GSK3β nuclear localization and tumor grade (p = 0.02), suggesting its association with tumor progression. The present study for the first time provided the clinical evidence in support of Wnt/β-catenin signaling upregulation in IDCs and key components of this pathway - E-cadherin, Slug and GSK3β with β-catenin in implementing EMT in these cells

Expression analysis of E-cadherin, Slug and GSK3β in invasive ductal carcinoma of breast

Energy Technology Data Exchange (ETDEWEB)

Prasad, Chandra P [Department of Anatomy, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi (India); Department of Biochemistry, All India Institute of Medical Sciences, New Delhi (India); Rath, Gayatri [Department of Anatomy, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi (India); Mathur, Sandeep [Department of Pathology, All India Institute of Medical Sciences, New Delhi (India); Bhatnagar, Dinesh [Department of Surgery, Vardhman Mahavir Medical College and Safdarjung Hospital, New Dehi (India); Parshad, Rajinder [Department of Surgery, All India Institute of Medical Sciences, New Delhi -110029 (India); Ralhan, Ranju [Department of Biochemistry, All India Institute of Medical Sciences, New Delhi (India); Sonshine Family Centre for Head & Neck Disease, Mount Sinai Hospital, 600 University Avenue, Room 6-500, Toronto, Ontario M5G 1X5 (Canada); Department of Otolaryngology-Head and Neck Surgery, Mount Sinai Hospital, 600 University Avenue, Room 6-500, Toronto, Ontario M5G 1X5 (Canada); Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, 600 University Avenue, Room 6-500, Toronto, Ontario M5G 1X5 (Canada); Department of Otolaryngology-Head and Neck Surgery, University of Toronto, Toronto, M5G 2N2 (Canada)

2009-09-14

Cancer progression is linked to a partially dedifferentiated epithelial cell phenotype. The signaling pathways Wnt, Hedgehog, TGF-β and Notch have been implicated in experimental and developmental epithelial mesenchymal transition (EMT). Recent findings from our laboratory confirm that active Wnt/β-catenin signaling is critically involved in invasive ductal carcinomas (IDCs) of breast. In the current study, we analyzed the expression patterns and relationships between the key Wnt/β-catenin signaling components- E-cadherin, Slug and GSK3β in IDCs of breast. Of the 98 IDCs analyzed, 53 (54%) showed loss/or reduced membranous staining of E-cadherin in tumor cells. Nuclear accumulation of Slug was observed in 33 (34%) IDCs examined. Loss or reduced level of cytoplasmic GSK3β expression was observed in 52/98 (53%) cases; while 34/98 (35%) tumors showed nuclear accumulation of GSK3β. Statistical analysis revealed associations of nuclear Slug expression with loss of membranous E-cadherin (p = 0.001); nuclear β-catenin (p = 0.001), and cytoplasmic β-catenin (p = 0.005), suggesting Slug mediated E-cadherin suppression via the activation of Wnt/β-catenin signaling pathway in IDCs. Our study also demonstrated significant correlation between GSK3β nuclear localization and tumor grade (p = 0.02), suggesting its association with tumor progression. The present study for the first time provided the clinical evidence in support of Wnt/β-catenin signaling upregulation in IDCs and key components of this pathway - E-cadherin, Slug and GSK3β with β-catenin in implementing EMT in these cells.

Wingless signalling alters the levels, subcellular distribution and dynamics of Armadillo and E-cadherin in third instar larval wing imaginal discs.

Directory of Open Access Journals (Sweden)

Ildiko M L Somorjai

2008-08-01

Full Text Available Armadillo, the Drosophila orthologue of vertebrate ss-catenin, plays a dual role as the key effector of Wingless/Wnt1 signalling, and as a bridge between E-Cadherin and the actin cytoskeleton. In the absence of ligand, Armadillo is phosphorylated and targeted to the proteasome. Upon binding of Wg to its receptors, the "degradation complex" is inhibited; Armadillo is stabilised and enters the nucleus to transcribe targets.Although the relationship between signalling and adhesion has been extensively studied, few in vivo data exist concerning how the "transcriptional" and "adhesive" pools of Armadillo are regulated to orchestrate development. We have therefore addressed how the subcellular distribution of Armadillo and its association with E-Cadherin change in larval wing imaginal discs, under wild type conditions and upon signalling. Using confocal microscopy, we show that Armadillo and E-Cadherin are spatio-temporally regulated during development, and that a punctate species becomes concentrated in a subapical compartment in response to Wingless. In order to further dissect this phenomenon, we overexpressed Armadillo mutants exhibiting different levels of activity and stability, but retaining E-Cadherin binding. Arm(S10 displaces endogenous Armadillo from the AJ and the basolateral membrane, while leaving E-Cadherin relatively undisturbed. Surprisingly, DeltaNArm(1-155 caused displacement of both Armadillo and E-Cadherin, results supported by our novel method of quantification. However, only membrane-targeted Myr-DeltaNArm(1-155 produced comparable nuclear accumulation of Armadillo and signalling to Arm(S10. These experiments also highlighted a row of cells at the A/P boundary depleted of E-Cadherin at the AJ, but containing actin.Taken together, our results provide in vivo evidence for a complex non-linear relationship between Armadillo levels, subcellular distribution and Wingless signalling. Moreover, this study highlights the importance of

Classic cadherin expressions balance postnatal neuronal positioning and dendrite dynamics to elaborate the specific cytoarchitecture of the mouse cortical area.

Science.gov (United States)

Egusa, Saki F; Inoue, Yukiko U; Asami, Junko; Terakawa, Youhei W; Hoshino, Mikio; Inoue, Takayoshi

2016-04-01

A unique feature of the mammalian cerebral cortex is in its tangential parcellation via anatomical and functional differences. However, the cellular and/or molecular machinery involved in cortical arealization remain largely unknown. Here we map expression profiles of classic cadherins in the postnatal mouse barrel field of the primary somatosensory area (S1BF) and generate a novel bacterial artificial chromosome transgenic (BAC-Tg) mouse line selectively illuminating nuclei of cadherin-6 (Cdh6)-expressing layer IV barrel neurons to confirm that tangential cellular assemblage of S1BF is established by postnatal day 5 (P5). When we electroporate the cadherins expressed in both barrel neurons and thalamo-cortical axon (TCA) terminals limited to the postnatal layer IV neurons, S1BF cytoarchitecture is disorganized with excess elongation of dendrites at P7. Upon delivery of dominant negative molecules for all classic cadherins, tangential cellular positioning and biased dendritic arborization of barrel neurons are significantly altered. These results underscore the value of classic cadherin-mediated sorting among neuronal cell bodies, dendrites and TCA terminals in postnatally elaborating the S1BF-specific tangential cytoarchitecture. Additionally, how the "protocortex" machinery affects classic cadherin expression profiles in the process of cortical arealization is examined and discussed. Copyright © 2015 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Infiltrating leukocytes confound the detection of E-cadherin promoter methylation in tumors

International Nuclear Information System (INIS)

Lombaerts, Marcel; Middeldorp, Janneke W.; Weide, Esther van der; Philippo, Katja; Wezel, Tom van; Smit, Vincent T.H.B.M.; Cornelisse, Cees J.; Cleton-Jansen, Anne-Marie

2004-01-01

Promoter hypermethylation is known to result in transcriptional downregulation of many genes including the CDH1 gene. In this study we set out to determine CDH1 promoter methylation in breast tumors with decreased or absent E-cadherin protein expression and without CDH1 gene mutations by methylation-specific PCR (MSP). Interestingly, some tumor samples with normal E-cadherin expression yielded a methylation-specific PCR product. We hypothesized that other cells than tumor cells contribute to these products. Since in normal breast tissue no CDH1 promoter methylation is detected, infiltrating leukocytes, often present in tumors, might account for these methylation-specific fragments. Indeed, a methylation-specific fragment is found in all twelve leukocyte samples tested. Furthermore, activated T-cells also yielded a methylation-specific fragment. Sequencing of these fragments reveals two distinct methylation profiles. Leukocytes have only partial methylation of some CpGs, while the tumor-associated methylation profile shows complete methylation of most CpGs. Therefore, to assess whether CDH1 methylation is tumor associated, sequencing of MSP products is a prerequisite. Here we show that out of six lobular tumors lacking E-cadherin protein expression, three have tumor-associated CDH1 promoter methylation while in three other tumors no methylation is detected

ERβ1 inhibits the migration and invasion of breast cancer cells through upregulation of E-cadherin in a Id1-dependent manner

International Nuclear Information System (INIS)

Zhou, Yan; Ming, Jia; Xu, Yan; Zhang, Yi; Jiang, Jun

2015-01-01

Highlights: • Expression of ERβ1 was positively correlated with E-cadherin in breast cancer cell. • ERβ1 upregulates E-cadherin expression in breast cancer cell lines. • ERβ1 upregulates E-cadherin expression in a Id1-dependent manner. - Abstract: ERβ1 is a member of the nuclear receptor superfamily of ligand-regulated transcription factors. It plays an important role in regulating the progression of breast cancer. However, the mechanisms of ERβ1 in tumorigenesis, metastasis and prognosis are still not fully clear. In this study, we showed that the expression of ERβ1 was positively correlated with E-cadherin expression in breast cancer cell lines. In addition, we found that ERβ1 upregulates E-cadherin expression in breast cancer cell lines. Furthermore, we also found that ERβ1 inhibits the migration and invasion of breast cancer cells and upregulated E-cadherin expression in a Id1-dependent manner. Taken together, our study provides further understanding of the molecular mechanism of ERβ1 in tumor metastasis and suggests the feasibility of developing novel therapeutic approaches to target Id1 to inhibit breast cancer metastasis

Expression of E-cadherin and β-catenin in basaloid and conventional squamous cell carcinoma of the oral cavity: are potential prognostic markers?

International Nuclear Information System (INIS)

Hanemann, João Adolfo Costa; Oliveira, Denise Tostes; Nonogaki, Suely; Nishimoto, Inês Nobuko; Carli, Marina Lara de; Landman, Gilles; Kowalski, Luiz Paulo

2014-01-01

Basaloid squamous cell carcinoma presents with a preference for the head and neck region, and shows a distinct aggressive behavior, with frequent local recurrences, regional and distant metastasis. The alterations in the cadherin-catenin complex are fundamental requirements for the metastasis process, and this is the first study to evaluate the immunostaining of E-cadherin and β-catenin in oral basaloid squamous cell carcinoma. Seventeen cases of this tumor located exclusively in the mouth were compared to 26 cases of poorly differentiated squamous cell carcinoma and 28 cases of well to moderately differentiated squamous cell carcinoma matched by stage and tumor site. The immunostaining of E-cadherin and β-catenin were evaluated in the three groups and compared to their clinicopathological features and prognosis. For groups poorly differentiated squamous cell carcinoma and basaloid squamous cell carcinoma, reduction or absence of E-cadherin staining was observed in more than 80.0% of carcinomas, and it was statistically significant compared to well to moderately differentiated squamous cell carcinoma (p = .019). A strong expression of β-catenin was observed in 26.9% and 20.8% of well to moderately differentiated squamous cell carcinoma and poorly differentiated squamous cell carcinoma, respectively, and in 41.2% of basaloid squamous cell carcinoma. The 5-year and 10-year overall and disease-free survival rates demonstrated no significant differences among all three groups. The clinical and biological behavior of three groups of the oral cavity tumors evaluated are similar. E-cadherin and β-catenin immunostaining showed no prognostic value for basaloid and conventional squamous cell carcinomas

Expression of E-cadherin and β-catenin in basaloid and conventional squamous cell carcinoma of the oral cavity: are potential prognostic markers?

Science.gov (United States)

Hanemann, João Adolfo Costa; Oliveira, Denise Tostes; Nonogaki, Suely; Nishimoto, Inês Nobuko; de Carli, Marina Lara; Landman, Gilles; Kowalski, Luiz Paulo

2014-06-03

Basaloid squamous cell carcinoma presents with a preference for the head and neck region, and shows a distinct aggressive behavior, with frequent local recurrences, regional and distant metastasis. The alterations in the cadherin-catenin complex are fundamental requirements for the metastasis process, and this is the first study to evaluate the immunostaining of E-cadherin and β-catenin in oral basaloid squamous cell carcinoma. Seventeen cases of this tumor located exclusively in the mouth were compared to 26 cases of poorly differentiated squamous cell carcinoma and 28 cases of well to moderately differentiated squamous cell carcinoma matched by stage and tumor site. The immunostaining of E-cadherin and β-catenin were evaluated in the three groups and compared to their clinicopathological features and prognosis. For groups poorly differentiated squamous cell carcinoma and basaloid squamous cell carcinoma, reduction or absence of E-cadherin staining was observed in more than 80.0% of carcinomas, and it was statistically significant compared to well to moderately differentiated squamous cell carcinoma (p = .019). A strong expression of β-catenin was observed in 26.9% and 20.8% of well to moderately differentiated squamous cell carcinoma and poorly differentiated squamous cell carcinoma, respectively, and in 41.2% of basaloid squamous cell carcinoma. The 5-year and 10-year overall and disease-free survival rates demonstrated no significant differences among all three groups. The clinical and biological behavior of three groups of the oral cavity tumors evaluated are similar. E-cadherin and β-catenin immunostaining showed no prognostic value for basaloid and conventional squamous cell carcinomas.

A Rhizobium leguminosarum CHDL- (Cadherin-Like-) Lectin Participates in Assembly and Remodeling of the Biofilm Matrix

DEFF Research Database (Denmark)

Vozza, Nicolás F.; Abdian, Patricia L; Russo, Daniela M

2016-01-01

In natural environments most bacteria live in multicellular structures called biofilms. These cell aggregates are enclosed in a self-produced polymeric extracellular matrix, which protects the cells, provides mechanical stability and mediates cellular cohesion and adhesion to surfaces. Although...... important advances were made in the identification of the genetic and extracellular factors required for biofilm formation, the mechanisms leading to biofilm matrix assembly, and the roles of extracellular proteins in these processes are still poorly understood. The symbiont Rhizobium leguminosarum requires...... the synthesis of the acidic exopolysaccharide and the PrsDE secretion system to develop a mature biofilm. PrsDE is responsible for the secretion of the Rap family of proteins that share one or two Ra/CHDL (cadherin-like-) domains. RapA2 is a calcium-dependent lectin with a cadherin-like β sheet structure...

Colorectal adenocarcinoma with mucinous component: relation of MMP-13, EGFR, and E-cadherin expressions to clinicopathological features and prognosis.

Science.gov (United States)

Foda, Abd Al-Rahman Mohammad; El-Hawary, Amira Kamal; Aziz, Azza Abdel

2015-06-01

The aim of this study was to compare colorectal adenocarcinoma with mucinous component, ordinary adenocarcinoma (OA) and mucinous adenocarcinoma (MA) regarding clinicopathological parameters, survival, EGFR, MMP-13, and E-cadherin. We studied tumor tissue specimens from 28 patients with adenocarcinoma with mucinous component, 47 with OA, and 56 with MA, who underwent radical surgery from January 2007 to January 2012 at the Gastroenterology Centre, Mansoura University, Egypt. High density manual tissue microarrays were constructed and immunohistochemistry for EGFR, MMP-13, and E-cadherin was done. Colorectal adenocarcinoma with mucinous component (AWMC) was significantly associated with more perineural invasion, lower EGFR, and MMP-13 expressions than OA, with no difference in E-cadherin expression. Conversely, only microscopic abscess formation was significantly more with colorectal AWMC than MC with no difference in EGFR, MMP-13 and E-cadherin expression between both groups. Colorectal AWMC showed a better survival than MA with no difference with OA. In a univariate analysis, EGFR, MMP-13, and E-cadherin expressions did not show a significant impact on disease-free or overall survival in patients with colorectal AWMC. Colorectal AWMC remains a vague entity that resembles OA in some clinicopathological and molecular respects as well as MA. © 2015 APMIS. Published by John Wiley & Sons Ltd.

Junctional E-cadherin/p120-catenin Is Correlated with the Absence of Supporting Cells to Hair Cells Conversion in Postnatal Mice Cochleae

Directory of Open Access Journals (Sweden)

Wen-wei Luo

2018-02-01

Full Text Available Notch inhibition is known to generate supernumerary hair cells (HCs at the expense of supporting cells (SCs in the mammalian inner ear. However, inhibition of Notch activity becomes progressively less effective at inducing SC-to-HC conversion in the postnatal cochlea and balance organs as the animal ages. It has been suggested that the SC-to-HC conversion capacity is inversely correlated with E-cadherin accumulation in postnatal mammalian utricles. However, whether E-cadherin localization is linked to the SC-to-HC conversion capacity in the mammalian inner ear is poorly understood. In the present study, we treated cochleae from postnatal day 0 (P0 with the Notch signaling inhibitor DAPT and observed apparent SC-to-HC conversion along with E-cadherin/p120ctn disruption in the sensory region. In addition, the SC-to-HC conversion capacity and E-cadherin/p120ctn disorganization were robust in the apex but decreased toward the base. We further demonstrated that the ability to regenerate HCs and the disruption of E-cadherin/p120ctn concomitantly decreased with age and ceased at P7, even after extended DAPT treatments. This timing is consistent with E-cadherin/p120ctn accumulation in the postnatal cochleae. These results suggest that the decreasing capacity of SCs to transdifferentiate into HCs correlates with E-cadherin/p120ctn localization in the postnatal cochleae, which might account for the absence of SC-to-HC conversion in the mammalian cochlea.

Junctional E-cadherin/p120-catenin Is Correlated with the Absence of Supporting Cells to Hair Cells Conversion in Postnatal Mice Cochleae.

Science.gov (United States)

Luo, Wen-Wei; Wang, Xin-Wei; Ma, Rui; Chi, Fang-Lu; Chen, Ping; Cong, Ning; Gu, Yu-Yan; Ren, Dong-Dong; Yang, Juan-Mei

2018-01-01

Notch inhibition is known to generate supernumerary hair cells (HCs) at the expense of supporting cells (SCs) in the mammalian inner ear. However, inhibition of Notch activity becomes progressively less effective at inducing SC-to-HC conversion in the postnatal cochlea and balance organs as the animal ages. It has been suggested that the SC-to-HC conversion capacity is inversely correlated with E-cadherin accumulation in postnatal mammalian utricles. However, whether E-cadherin localization is linked to the SC-to-HC conversion capacity in the mammalian inner ear is poorly understood. In the present study, we treated cochleae from postnatal day 0 (P0) with the Notch signaling inhibitor DAPT and observed apparent SC-to-HC conversion along with E-cadherin/p120ctn disruption in the sensory region. In addition, the SC-to-HC conversion capacity and E-cadherin/p120ctn disorganization were robust in the apex but decreased toward the base. We further demonstrated that the ability to regenerate HCs and the disruption of E-cadherin/p120ctn concomitantly decreased with age and ceased at P7, even after extended DAPT treatments. This timing is consistent with E-cadherin/p120ctn accumulation in the postnatal cochleae. These results suggest that the decreasing capacity of SCs to transdifferentiate into HCs correlates with E-cadherin/p120ctn localization in the postnatal cochleae, which might account for the absence of SC-to-HC conversion in the mammalian cochlea.

Comparative study of the Ar and He atmospheric pressure plasmas on E-cadherin protein regulation for plasma-mediated transdermal drug delivery

Science.gov (United States)

Lee, Hyun Young; Hae Choi, Jeong; Hong, Jin Woo; Kim, Gyoo Cheon; Lee, Hae June

2018-05-01

The effects of argon plasma (ArP) and helium plasma (HeP) jets on E-cadherin protein function have been tested in order to choose the working gas for a better plasma-mediated transdermal drug delivery. The plasma-mediated changes of the E-cadherin function and the skin penetration efficacies of epidermal growth factor (EGF) were monitored in vitro using HaCaT human keratinocytes and in vivo using hairless mice. The ArP showed higher efficacy for E-cadherin regulation and EGF absorption than HeP under the same applied voltage and the same gas flow rate. The ArP generates higher volume power density, higher discharge current peak, and more reactive species than HeP, especially for OH with the same operating parameters. Moreover, the effect of ArP on E-cadherin function was blocked by the use of a grounded metal mesh. Taken together, this study presents the possibility that the synergetic effect of negative charges with radicals plays an important role in plasma-mediated E-cadherin regulation, which leads to enhanced transdermal drug delivery.

A study of RUNX3, E-cadherin and β-catenin in CagA-positive Helicobacter pylori associated chronic gastritis in Saudi patients.

Science.gov (United States)

Wagih, H M; El-Ageery, S M; Alghaithy, A A

2015-04-01

H. pylori is the most important risk factor for gastric carcinoma. CagA-positive H. pylori is associated with an increased risk for gastric cancer compared with negative strains. RUNX3 is a tumor suppressor gene, which is related to the genesis of gastric cancer. β-catenin is integrated with E-cadherin in the cell membrane, and aberrant expression of the complex was reported in gastric carcinoma. Aim of this paper is to determine of the relation between RUNX3, E-cadherin and β-catenin in chronic gastritis associated with cagA-positive H. pylori infection. Retrospective study was done on formalin fixed paraffin embedded gastric biopsies blocks of 90 patients diagnosed as H. pylori associated chronic gastritis. H. pylori was detected using modified Giemsa stain. Nested PCR was used for detection of cagA, reverse transcription-PCR for detection of RUNX3 and immunohistochemistry for detection of E-cadherin and β-catenin. Fifty percent of cases were found to be cagA positive. CagA was significantly associated with the intensity of mononuclear inflammation, the intensity of neutrophilic inflammation, the degree of mucosal atrophy and loss of RUNX3 but not with the density of H. pylori, intestinal metaplasia, E-cadherin or β-catenin. There was significant relation between loss of RUNX3 and increasing density of H. pylori, intensity of neutrophilic inflammation, mucosal atrophy and intestinal metaplasia. RUNX3 was found to be significantly correlated with E-cadherin but not with β-catenin. E-cadherin showed decreased expression in 36.7% of biopsies while, β-catenin was decreased in 33% of biopsies. Loss of RUNX3, E-cadherin and β-catenin was considered early events in the cascade of gastric carcinoma development. Loss of RUNX3 but neither E-cadherin nor β-catenin was related to cagA positive H. pylori strains.

Association of E-Cadherin Gene 3_-UTR C/T Polymorphism with ...

African Journals Online (AJOL)

Endometriosis (EM) is one of the most frequent diseases in gynecology; endometriotic cells display invasive characteristics,despite their benign histological appearance. Epithelial-cadherin (Ecadherin)is a cell-cell adhesive molecule which maintains cell integrity and communication between the intracellular and ...

miR-151a induces partial EMT by regulating E-cadherin in NSCLC cells

DEFF Research Database (Denmark)

Daugaard, Iben; Sanders, K J; Idica, A

2017-01-01

mortality. Here, we demonstrate that miR-151a is overexpressed in non-small cell lung cancer (NSCLC) patient specimens, as compared to healthy lung. In addition, miR-151a overexpression promotes proliferation, epithelial-to-mesenchymal transition (EMT) and induces tumor cell migration and invasion of NSCLC......-cadherin in miR-151a NSCLC cell lines potently repressed miR-151a-induced partial EMT and cell migration of NSCLC cells. In conclusion, our findings suggest that miR-151a functions as an oncomiR in NSCLC by targeting E-cadherin mRNA and inducing proliferation, migration and partial EMT....

Reduced E-Cadherin and Aberrant β-Catenin Expression are Associated With Advanced Disease in Signet-Ring Cell Carcinomas.

Science.gov (United States)

Ma, Yihong R; Ren, Zhiyong; Conner, Michael G; Siegal, Gene P; Wei, Shi

2017-07-01

Signet-ring cell carcinomas (SRCCs) tend to present at higher stages and thus are generally associated with a worse prognosis. It has been postulated that a deficiency of E-cadherin may be causal in the pathogenesis of SRCC in animal models. In this study, we systemically analyzed the expression of E-cadherin and β-catenin, a key component of the cadherin complex, in 137 consecutive SRCCs of various organ systems to explore the significance of these molecules in the pathogenesis and progression of SRCCs. Seventy-six percent of SRCCs showed loss or reduced E-cadherin expression. Aberrant β-catenin expression, defined as loss of membranous expression and nuclear/cytoplasmic subcellular localization, was observed in 60% of these cases, with the altered β-catenin expression observed most commonly in the breast (93%) and least in the lung (38%) primaries. Further, the aberrant β-catenin was significantly associated with pathologic nodal stage (P=0.002) and clinical stage (P=0.02). Our findings demonstrated that reduced membranous E-cadherin and aberrant β-catenin expression were frequent events in SRCCs of various organs, and that the altered β-catenin expression was significantly associated with advanced disease. The observations further support the importance of these molecules in the pathogenesis of SRCCs, and indicate the fundamental role of the Wnt/β-catenin signaling pathway in the progression of these tumors. Further investigations of the downstream molecules in this cascade may provide potential novel therapeutic targets for this aggressive tumor type.

P-cadherin expression and survival rate in oral squamous cell carcinoma:an immunohistochemical study

Directory of Open Access Journals (Sweden)

Laino Gregorio

2005-06-01

Full Text Available Abstract Background P-cadherin (P-cad is a transmembrane molecule involved in the cell-cell adhesion and similar to E-cadherin (E-cad, but less investigated in oncology, especially in in vivo studies. Aims of the present study were to assess the prevalence of P-cad expression in oral squamous cell carcinoma (OSCC and to verify whether P-cad can be considered a marker of prognosis in patients with OSCC. Methods In a retrospective study, a cohort of 67 OSCC patients was investigated for P-cad expression and its cellular localization by immunohistochemistry; some respective healthy margins of resection were similarly investigated as standard controls. After grouping for P-cad expression, OSCCs were statistically analyzed for the variables age, gender, histological grading (G, TNM, Staging, and overall survival rate. Univariate and multivariate analyses were performed. Results 37 cases (55.2% of OSCC showed membranous/cytoplasmic positivity for P-cad, whereas 30 (44.8 % were negative. Although with some differences in membranous vs cytoplasmic localization of P-cad in OSCC with different G, no statistical association was found between P-cad expression and any variables considered at baseline. In terms of prognostic significance, P-cad non expression was found to have an independent association with poorer overall survival rate than P-cad expressing group (P = 0.056; moreover, among P-cad +ve patients the best prognosis was for those OSCC with membranous (P Conclusion On the basis of these results, it is possible to suggest P-cad as an early marker of poor prognosis. The abnormal or lack of P-cad expression could constitute an hallmark of aggressive biological behavior in OSCC

Dual pulse-chase microscopy reveals early divergence in the biosynthetic trafficking of the Na,K-ATPase and E-cadherin

Science.gov (United States)

Farr, Glen A.; Hull, Michael; Stoops, Emily H.; Bateson, Rosalie; Caplan, Michael J.

2015-01-01

Recent evidence indicates that newly synthesized membrane proteins that share the same distributions in the plasma membranes of polarized epithelial cells can pursue a variety of distinct trafficking routes as they travel from the Golgi complex to their common destination at the cell surface. In most polarized epithelial cells, both the Na,K-ATPase and E-cadherin are localized to the basolateral domains of the plasma membrane. To examine the itineraries pursued by newly synthesized Na,K-ATPase and E-cadherin in polarized MDCK epithelial cells, we used the SNAP and CLIP labeling systems to fluorescently tag temporally defined cohorts of these proteins and observe their behaviors simultaneously as they traverse the secretory pathway. These experiments reveal that E-cadherin is delivered to the cell surface substantially faster than is the Na,K-ATPase. Furthermore, the surface delivery of newly synthesized E-cadherin to the plasma membrane was not prevented by the 19°C temperature block that inhibits the trafficking of most proteins, including the Na,K-ATPase, out of the trans-Golgi network. Consistent with these distinct behaviors, populations of newly synthesized E-cadherin and Na,K-ATPase become separated from one another within the trans-Golgi network, suggesting that they are sorted into different carrier vesicles that mediate their post-Golgi trafficking. PMID:26424804

Evaluation of methylation pattern in promoter region of E-cadherin ...

African Journals Online (AJOL)

The epithelial cadherin gene (CDH1) has been identified as a tumor suppressor gene located within the 16q22.1 region. The CDH1 gene encodes a transmembrane glycoprotein involved in cell to cell adhesion and loss of CDH1 expression contributes to increased proliferation, invasion and metastasis in breast carcinoma.

Mast cells infiltration and decreased E-cadherin expression in ketamine-induced cystitis

Directory of Open Access Journals (Sweden)

Mengqiang Li

2015-01-01

Conclusions: Increased mast cells in bladder wall and downregulated expression of E-cadherin junction protein in epithelial cells were probably associated with interstitial inflammation and fissures in mucosa. It implied that ketamine induced an interstitial cystitis.

Saccharomyces boulardii CNCM I-745 Restores intestinal Barrier Integrity by Regulation of E-cadherin Recycling.

Science.gov (United States)

Terciolo, Chloé; Dobric, Aurélie; Ouaissi, Mehdi; Siret, Carole; Breuzard, Gilles; Silvy, Françoise; Marchiori, Bastien; Germain, Sébastien; Bonier, Renaté; Hama, Adel; Owens, Roisin; Lombardo, Dominique; Rigot, Véronique; André, Frédéric

2017-08-01

Alteration in intestinal permeability is the main factor underlying the pathogenesis of many diseases affecting the gut, such as inflammatory bowel disease [IBD]. Characterization of molecules targeting the restoration of intestinal barrier integrity is therefore vital for the development of alternative therapies. The yeast Saccharomyces boulardii CNCM I-745 [Sb], used to prevent and treat antibiotic-associated infectious and functional diarrhea, may have a beneficial effect in the treatment of IBD. We analyzed the impact of Sb supernatant on tissue integrity and components of adherens junctions using cultured explants of colon from both IBD and healthy patients. To evaluate the pathways by which Sb regulates the expression of E-cadherin at the cell surface, we developed in vitro assays using human colonic cell lines, including cell aggregation, a calcium switch assay, real-time measurement of transepithelial electrical resistance [TEER] and pulse-chase experiments. We showed that Sb supernatant treatment of colonic explants protects the epithelial morphology and maintains E-cadherin expression at the cell surface. In vitro experiments revealed that Sb supernatant enhances E-cadherin delivery to the cell surface by re-routing endocytosed E-cadherin back to the plasma membrane. This process, involving Rab11A-dependent recycling endosome, leads to restoration of enterocyte adherens junctions, in addition to the overall restoration and strengthening of intestinal barrier function. These findings open new possibilities of discovering novel options for prevention and therapy of diseases that affect intestinal permeability. Copyright © 2017 European Crohn's and Colitis Organisation (ECCO). Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com

PTEN Loss in E-Cadherin-Deficient Mouse Mammary Epithelial Cells Rescues Apoptosis and Results in Development of Classical Invasive Lobular Carcinoma

NARCIS (Netherlands)

Boelens, M.C.; Nethe, M.; Klarenbeek, S.; de Ruiter, J.R.; Schut, E.; Bonzanni, N.; Zeeman, A.L.; Wientjens, E.; van der Burg, E.; Wessels, L.; van Amerongen, R.; Jonkers, J.

2016-01-01

Invasive lobular carcinoma (ILC) is an aggressive breast cancer subtype with poor response to chemotherapy. Besides loss of E-cadherin, a hallmark of ILC, genetic inactivation of PTEN is frequently observed in patients. Through concomitant Cre-mediated inactivation of E-cadherin and PTEN in mammary

Search Directions for Direct H2O2 Synthesis Catalysts Starting from Au-12 Nanoclusters

DEFF Research Database (Denmark)

Grabow, Lars; Larsen, Britt Hvolbæk; Falsig, Hanne

2012-01-01

that the rate of H2O2 and H2O formation can be determined from a single descriptor, namely, the binding energy of oxygen (E-O). Our model predicts the search direction starting from an Au-12 nanocluster for an optimal catalyst in terms of activity and selectivity for direct H2O2 synthesis. Taking also stability......We present density functional theory calculations on the direct synthesis of H2O2 from H-2 and O-2 over an Au-12 corner model of a gold nanoparticle. We first show a simple route for the direct formation of H2O2 over a gold nanocatalyst, by studying the energetics of 20 possible elementary...... reactions involved in the oxidation of H-2 by O-2. The unwanted side reaction to H2O is also considered. Next we evaluate the degree of catalyst control and address the factors controlling the activity and the selectivity. By combining well-known energy scaling relations with microkinetic modeling, we show...

The simultaneous expression of both ephrin B3 receptor and E-cadherin in Barrett`s adenocarcinoma is associated with favorable clinical staging

Directory of Open Access Journals (Sweden)

Schauer Matthias C

2012-05-01

Full Text Available Abstract Background In intestinal epithelium, tyrosine kinase receptor Ephrin B3 (Eph B3 maintains the architecture of the crypt-villus axis by repulsive interaction with its ligand ephrin-B1. While loss of Eph B3 is linked to colorectal cancer initiation, overexpression of Eph B3 in cancer cell lines inhibits growth and induces functional changes with decreased mesenchymal and increased epithelial markers. In order to study this tumor suppressor activity of Eph B3 in esophageal adenocarcinoma we analyzed the simultaneous expression of Eph B3 and E-cadherin in both the healthy esophagus and in Barrett’s carcinoma. Methods Simultaneous expression of Eph B3 and E-cadherin was investigated in samples from 141 patients with Barrett’s carcinoma and from 20 healthy esophagi using immunhistology and quantitative PCR. Results from healthy squamous epithelium, Barrett’s metaplasia and staging-specific esophageal adenocarcinoma were correlated. Results A significantly reduced E-cadherin mRNA expression could be detected in adenocarcinoma compared to dysplasia. The immunhistological activity of E-cadherin and Eph B3 was reduced in adenocarcinoma compared to dysplasia or healthy esophageal mucosa. The intracellular E-cadherin distribution changed significantly from the cytoplasm to the membrane, when the Eph receptor was simultaneously expressed. Simultaneous expression of E-cadherin and Eph B3 showed a significant inverse correlation to tumor stage. Conclusions We present novel evidence of the tumor suppressor activity of Eph B3 in esophageal adenocarcinoma possibly due to the impact on redistribution of cellular E-cadherin to the membrane. Our results suggest that this effect might play a role in the dysplasia-adenocarcinoma sequence, the infiltrative growth pattern and the development of lymph node metastases.

25 Years of Tension over Actin Binding to the Cadherin Cell Adhesion Complex: The Devil is in the Details.

Science.gov (United States)

Nelson, W James; Weis, William I

2016-07-01

Over the past 25 years, there has been a conceptual (re)evolution in understanding how the cadherin cell adhesion complex, which contains F-actin-binding proteins, binds to the actin cytoskeleton. There is now good synergy between structural, biochemical, and cell biological results that the cadherin-catenin complex binds to F-actin under force. Copyright © 2016 Elsevier Ltd. All rights reserved.

Binding specificity of Bacillus thuringiensis Cry1Aa for purified, native Bombyx mori aminopeptidase N and cadherin-like receptors

Directory of Open Access Journals (Sweden)

Jenkins Jeremy L

2001-10-01

Full Text Available Abstract Background To better understand the molecular interactions of Bt toxins with non-target insects, we have examined the real-time binding specificity and affinity of Cry1 toxins to native silkworm (Bombyx mori midgut receptors. Previous studies on B. mori receptors utilized brush border membrane vesicles or purifed receptors in blot-type assays. Results The Bombyx mori (silkworm aminopeptidase N (APN and cadherin-like receptors for Bacillus thuringiensis insecticidal Cry1Aa toxin were purified and their real-time binding affinities for Cry toxins were examined by surface plasmon resonance. Cry1Ab and Cry1Ac toxins did not bind to the immobilized native receptors, correlating with their low toxicities. Cry1Aa displayed moderate affinity for B. mori APN (75 nM, and unusually tight binding to the cadherin-like receptor (2.6 nM, which results from slow dissociation rates. The binding of a hybrid toxin (Aa/Aa/Ac was identical to Cry1Aa. Conclusions These results indicate domain II of Cry1Aa is essential for binding to native B. mori receptors and for toxicity. Moreover, the high-affinity binding of Cry1Aa to native cadherin-like receptor emphasizes the importance of this receptor class for Bt toxin research.

Binding specificity of Bacillus thuringiensis Cry1Aa for purified, native Bombyx mori aminopeptidase N and cadherin-like receptors

Science.gov (United States)

Jenkins, Jeremy L; Dean, Donald H

2001-01-01

Background To better understand the molecular interactions of Bt toxins with non-target insects, we have examined the real-time binding specificity and affinity of Cry1 toxins to native silkworm (Bombyx mori) midgut receptors. Previous studies on B. mori receptors utilized brush border membrane vesicles or purifed receptors in blot-type assays. Results The Bombyx mori (silkworm) aminopeptidase N (APN) and cadherin-like receptors for Bacillus thuringiensis insecticidal Cry1Aa toxin were purified and their real-time binding affinities for Cry toxins were examined by surface plasmon resonance. Cry1Ab and Cry1Ac toxins did not bind to the immobilized native receptors, correlating with their low toxicities. Cry1Aa displayed moderate affinity for B. mori APN (75 nM), and unusually tight binding to the cadherin-like receptor (2.6 nM), which results from slow dissociation rates. The binding of a hybrid toxin (Aa/Aa/Ac) was identical to Cry1Aa. Conclusions These results indicate domain II of Cry1Aa is essential for binding to native B. mori receptors and for toxicity. Moreover, the high-affinity binding of Cry1Aa to native cadherin-like receptor emphasizes the importance of this receptor class for Bt toxin research. PMID:11722800

Expression of RKIP, E-cadherin and NF-kB p65 in esophageal squamous cell carcinoma and their correlations.

Science.gov (United States)

Ping, Fu-Min; Liu, Gui-Jing; Liu, Zhi-Jun; Li, Hai-Bin; Zhai, Jian-Wen; Li, Shu-Xia; Liu, Yue-Mei; Li, Bao-Wei; Wei, Hong

2015-01-01

To detect the expression of RKIP, E-cadherin and NF-kB p65 in esophageal squamous cell carcinoma (ESCC) and study their correlations. Steptavidin-peroxidase (S-P) method was employed to detect the expressions of RKIP, E-cadherin and NF-kB p65 in ESCC tissues from 77 cases and paracancerous tissues from 77 cases. The correlations between their expressions and clinicopathological indices and between the expressions of these proteins themselves were analyzed. The expressions of RKIP and E-cadherin in ESCC tissues were obviously lower than those in the paracancerous tissues (PkB p65 in ESCC tissues was correlated with clinical staging, lymph node metastasis and tumor differentiation (PkB p65 in ESCC tissues (PkB p65.

Phosphorylated hepatocyte growth factor receptor/c-Met is associated with tumor growth and prognosis in patients with bladder cancer: correlation with matrix metalloproteinase-2 and -7 and E-cadherin.

Science.gov (United States)

Miyata, Yasuyoshi; Sagara, Yuji; Kanda, Shigeru; Hayashi, Tomayoshi; Kanetake, Hiroshi

2009-04-01

Hepatocyte growth factor receptor/c-Met is associated with malignant aggressiveness and survival in various cancers including bladder cancer. Although phosphorylation of hepatocyte growth factor receptor/c-Met is essential for its function, the pathologic significance of phosphorylated hepatocyte growth factor receptor/c-Met in bladder cancer remains elusive. We investigated the clinical significance of its expression, and its correlation with cancer cell progression-related molecules. The expression levels of 2 tyrosine residues of hepatocyte growth factor receptor/c-Met (pY1234/1235 and pY1349) were examined immunohistochemically in 133 specimens with nonmetastatic bladder cancer. We also investigated their correlation with matrix metalloproteinase-1, -2, -7, and -14; urokinase-type plasminogen activator; E-cadherin; CD44 standard, variant 3, and variant 6; and vascular endothelial growth factor. Expression of phosphorylated hepatocyte growth factor receptor/c-Met was detected in cancer cells, but was rare in normal urothelial cells. Although hepatocyte growth factor receptor/c-Met, pY1234/1235 hepatocyte growth factor receptor/c-Met, and pY1349 hepatocyte growth factor receptor/c-Met were associated with pT stage, multivariate analysis identified pY1349 hepatocyte growth factor receptor/c-met expression only as a significant factor for high pT stage. Expression of pY1349 hepatocyte growth factor receptor/c-Met was a marker of metastasis and (P = .001) and cause-specific survival (P = .003). Expressions of matrix metalloproteinase-2, matrix metalloproteinase-7, and E-cadherin correlated with pY1349 hepatocyte growth factor receptor/c-Met expression. Our results demonstrated that pY1349 hepatocyte growth factor receptor/c-Met plays an important role in tumor development, and its expression is a significant predictor of metastasis and survival of patients with bladder cancer. The results suggest that these activities are mediated, at least in part, by matrix

Neuron-Derived ADAM10 Production Stimulates Peripheral Nerve Injury-Induced Neuropathic Pain by Cleavage of E-Cadherin in Satellite Glial Cells.

Science.gov (United States)

Li, Jian; Ouyang, Qing; Chen, Cheng-Wen; Chen, Qian-Bo; Li, Xiang-Nan; Xiang, Zheng-Hua; Yuan, Hong-Bin

2017-09-01

Increasing evidence suggests the potential involvement of metalloproteinase family proteins in the pathogenesis of neuropathic pain, although the underlying mechanisms remain elusive. Using the spinal nerve ligation model, we investigated whether ADAM10 proteins participate in pain regulation. By implementing invitro methods, we produced a purified culture of satellite glial cells to study the underlying mechanisms of ADAM10 in regulating neuropathic pain. Results showed that the ADAM10 protein was expressed in calcitonin gene-related peptide (CGRP)-containing neurons of the dorsal root ganglia, and expression was upregulated following spinal nerve ligation surgery invivo. Intrathecal administration of GI254023X, an ADAM10 selective inhibitor, to the rats one to three days after spinal nerve ligation surgery attenuated the spinal nerve ligation-induced mechanical allodynia and thermal hyperalgesia. Intrathecal injection of ADAM10 recombinant protein simulated pain behavior in normal rats to a similar extent as those treated by spinal nerve ligation surgery. These results raised a question about the relative contribution of ADAM10 in pain regulation. Further results showed that ADAM10 might act by cleaving E-cadherin, which is mainly expressed in satellite glial cells. GI254023X reversed spinal nerve ligation-induced downregulation of E-cadherin and activation of cyclooxygenase 2 after spinal nerve ligation. β-catenin, which creates a complex with E-cadherin in the membranes of satellite glial cells, was also downregulated by spinal nerve ligation surgery in satellite glial cells. Finally, knockdown expression of β-catenin by lentiviral infection in purified satellite glial cells increased expression of inducible nitric oxide synthase and cyclooxygenase 2. Our findings indicate that neuron-derived ADAM10 production stimulates peripheral nerve injury-induced neuropathic pain by cleaving E-cadherin in satellite glial cells. © 2017 American Academy of Pain Medicine

Opposite Roles of Furin and PC5A in N-Cadherin Processing

Directory of Open Access Journals (Sweden)

Deborah Maret

2012-10-01

Full Text Available We recently demonstrated that lack of Furin-processing of the N-cadherin precursor (proNCAD in highly invasive melanoma and brain tumor cells results in the cell-surface expression of a nonadhesive protein favoring cell migration and invasion in vitro. Quantitative polymerase chain reaction analysis of malignant human brain tumor cells revealed that of all proprotein convertases (PCs only the levels of Furin and PC5A are modulated, being inversely (Furin or directly (PC5A correlated with brain tumor invasive capacity. Intriguingly, the N-terminal sequence following the Furin-activated NCAD site (RQKR↓DW161, mouse nomenclature reveals a second putative PC-processing site (RIRSDR↓DK189 located in the first extracellular domain. Cleavage at this site would abolish the adhesive functions of NCAD because of the loss of the critical Trp161. This was confirmed upon analysis of the fate of the endogenous prosegment of proNCAD in human malignant glioma cells expressing high levels of Furin and low levels of PC5A (U343 or high levels of PC5A and negligible Furin levels (U251. Cellular analyses revealed that Furin is the best activating convertase releasing an ∼17-kDa prosegment, whereas PC5A is the major inactivating enzyme resulting in the secretion of an ∼20-kDa product. Like expression of proNCAD at the cell surface, cleavage of the NCAD molecule at RIRSDR↓DK189 renders the U251 cancer cells less adhesive to one another and more migratory. Our work modifies the present view on posttranslational processing and surface expression of classic cadherins and clarifies how NCAD possesses a range of adhesive potentials and plays a critical role in tumor progression.

PTEN Loss in E-Cadherin-Deficient Mouse Mammary Epithelial Cells Rescues Apoptosis and Results in Development of Classical Invasive Lobular Carcinoma

Directory of Open Access Journals (Sweden)

Mirjam C. Boelens

2016-08-01

Full Text Available Invasive lobular carcinoma (ILC is an aggressive breast cancer subtype with poor response to chemotherapy. Besides loss of E-cadherin, a hallmark of ILC, genetic inactivation of PTEN is frequently observed in patients. Through concomitant Cre-mediated inactivation of E-cadherin and PTEN in mammary epithelium, we generated a mouse model of classical ILC (CLC, the main histological ILC subtype. While loss of E-cadherin induced cell dissemination and apoptosis, additional PTEN inactivation promoted cell survival and rapid formation of invasive mammary tumors that recapitulate the histological and molecular features, estrogen receptor (ER status, growth kinetics, metastatic behavior, and tumor microenvironment of human CLC. Combined inactivation of E-cadherin and PTEN is sufficient to cause CLC development. These CLCs showed significant tumor regression upon BEZ235-mediated inhibition of PI3K signaling. In summary, this mouse model provides important insights into CLC development and suggests inhibition of phosphatidylinositol 3-kinase (PI3K signaling as a potential therapeutic strategy for targeting CLC.

Mining the O-mannose glycoproteome reveals cadherins as major O-mannosylated glycoproteins

DEFF Research Database (Denmark)

Vester-Christensen, Malene B; Halim, Adnan; Joshi, Hiren Jitendra

2013-01-01

The metazoan O-mannose (O-Man) glycoproteome is largely unknown. It has been shown that up to 30% of brain O-glycans are of the O-Man type, but essentially only alpha-dystroglycan (α-DG) of the dystrophin-glycoprotein complex is well characterized as an O-Man glycoprotein. Defects in O-Man...... glycosylation underlie congenital muscular dystrophies and considerable efforts have been devoted to explore this O-glycoproteome without much success. Here, we used our SimpleCell strategy using nuclease-mediated gene editing of a human cell line (MDA-MB-231) to reduce the structural heterogeneity of O-Man...... glycans and to probe the O-Man glycoproteome. In this breast cancer cell line we found that O-Man glycosylation is primarily found on cadherins and plexins on β-strands in extracellular cadherin and Ig-like, plexin and transcription factor domains. The positions and evolutionary conservation of O-Man...

LincRNA-p21 inhibits invasion and metastasis of hepatocellular carcinoma through miR-9/E-cadherin cascade signaling pathway molecular mechanism

Directory of Open Access Journals (Sweden)

Ding G

2017-06-01

Full Text Available Gangqiang Ding, Zhen Peng, Jia Shang, Yi Kang, Huibin Ning, Chongshan Mao Department of Infectious Diseases, People’s Hospital of Zhengzhou University, Henan Provincial People’s Hospital, Zhengzhou, China Abstract: In the previous study, it was found that long intergenic noncoding RNA-p21 (lincRNA-p21 was downregulated in hepatocellular carcinoma (HCC and lincRNA-p21 overexpression inhibited tumor invasion through inducing epithelial–mesenchymal transition. However, the underlying mechanism was not fully elaborated. In this study, lincRNA-p21 expression was measured in 12 paired HCC and nontumor adjacent normal tissues by ­quantitative real-time polymerase chain reaction. The effects of lincRNA-p21 on HCC cells were studied using lentivirus expressing lincRNA-p21 vector in vitro. The association between lincRNA-p21 level and miR-9 level was tested with the Spearman rank correlation. The effects of miR-9 on HCC cells were studied by using miR-9 inhibitor in vitro. Luciferase assay was used to validate the target of miR-9. The results showed that lincRNA-p21 was downregulated in human HCC tissues and cell lines. LincRNA-p21 overexpression significantly inhibited HCC cell migration and invasion in vitro. Besides, lincRNA-p21 negatively regulated miR-9 expression level, and miR-9 was upregulated in human HCC tissues and cells. MiR-9 knockdown inhibited HCC cell migration and invasion in vitro. Finally, the luciferase assay results showed that E-cadherin was a direct target of miR-9. The expression level of E-cadherin was found to be regulated by lincRNA-p21 and miR-9. Altogether, the results suggested that lincRNA-p21 inhibits migration and invasion of HCC cells through regulating miR-9-mediated E-cadherin cascade signaling pathway. Keywords: hepatocellular carcinoma, lincRNA-p21, miR-9, E-cadherin, epithelial–mesenchymal transition

Expression of P-aPKC-iota, E-cadherin, and beta-catenin related to invasion and metastasis in hepatocellular carcinoma.

Science.gov (United States)

Du, Guang-Sheng; Wang, Jian-Ming; Lu, Jin-Xi; Li, Qiang; Ma, Chao-Qun; Du, Ji-Tao; Zou, Sheng-Quan

2009-06-01

Atypical protein kinase C iota (aPKC-iota) and its associated intracellular molecules, E-cadherin and beta-catenin, are important for cell polarization in tumorigenesis and progression. Expression of aPKC-iota, P-aPKC-iota (activated aPKC-iota), E-cadherin, and beta-catenin in hepatocellular carcinoma (HCC) was measured, and correlation with clinicopathological characteristics of HCC was analyzed. Paraffin-embedded tumor tissue was obtained from patients with HCC after resection without preoperative radiotherapy or chemotherapy. Gene expression was detected by polymerase chain reaction (PCR), and protein expression was detected by immunohistochemistry and Western blot analysis. Expressions of aPKC-iota, P-aPKC-iota, E-cadherin, and beta-catenin were analyzed with relation to the clinicopathological data. The gene and protein expression of aPKC-iota are obviously higher in HCC tissues than that in peritumoral tissues and normal tissues by semiquantitative PCR and immunohistochemistry methods. Accumulation of aPKC-iota in HCC cytoplasm and nucleolus inhibited the later formation of belt-like adherens junctions (AJs) and/or tight junctions (TJs) in cell-cell contact. E-cadherin was reduced and accumulation of cytoplasm beta-catenin was increased in HCC. The expression of aPKC-iota was closely related to pathological differentiation, tumor size, invasion, and metastasis of HCC. Accumulation of cytoplasm aPKC-iota may reflect pathological differentiation, invasion, and metastasis potential of HCC. In this regard, our study on HCC revealed the potential usefulness of aPKC-iota, E-cadherin, and beta-catenin as a prognostic marker, closely related to pathological differentiation, invasion, metastasis, and prognosis of HCC.

Signaling mechanisms of neurite outgrowth induced by the cell adhesion molecules NCAM and N-cadherin

DEFF Research Database (Denmark)

Hansen, S M; Berezin, V; Bock, E

2008-01-01

Formation of appropriate neural circuits depends on a complex interplay between extracellular guiding cues and intracellular signaling events that result in alterations of cytoskeletal dynamics and a neurite growth response. Surface-expressed cell adhesion molecules (CAMs) interact with the surro......Formation of appropriate neural circuits depends on a complex interplay between extracellular guiding cues and intracellular signaling events that result in alterations of cytoskeletal dynamics and a neurite growth response. Surface-expressed cell adhesion molecules (CAMs) interact...... extracellular guidance cues to intracellular events and thereby regulating neurite outgrowth. In this review, we focus on two CAMs, the neural cell adhesion molecule (NCAM) and N-cadherin, and their ability to mediate signaling associated with a neurite outgrowth response. In particular, we will focus on direct...

PTEN Loss in E-Cadherin-Deficient Mouse Mammary Epithelial Cells Rescues Apoptosis and Results in Development of Classical Invasive Lobular Carcinoma.

Science.gov (United States)

Boelens, Mirjam C; Nethe, Micha; Klarenbeek, Sjoerd; de Ruiter, Julian R; Schut, Eva; Bonzanni, Nicola; Zeeman, Amber L; Wientjens, Ellen; van der Burg, Eline; Wessels, Lodewyk; van Amerongen, Renée; Jonkers, Jos

2016-08-23

Invasive lobular carcinoma (ILC) is an aggressive breast cancer subtype with poor response to chemotherapy. Besides loss of E-cadherin, a hallmark of ILC, genetic inactivation of PTEN is frequently observed in patients. Through concomitant Cre-mediated inactivation of E-cadherin and PTEN in mammary epithelium, we generated a mouse model of classical ILC (CLC), the main histological ILC subtype. While loss of E-cadherin induced cell dissemination and apoptosis, additional PTEN inactivation promoted cell survival and rapid formation of invasive mammary tumors that recapitulate the histological and molecular features, estrogen receptor (ER) status, growth kinetics, metastatic behavior, and tumor microenvironment of human CLC. Combined inactivation of E-cadherin and PTEN is sufficient to cause CLC development. These CLCs showed significant tumor regression upon BEZ235-mediated inhibition of PI3K signaling. In summary, this mouse model provides important insights into CLC development and suggests inhibition of phosphatidylinositol 3-kinase (PI3K) signaling as a potential therapeutic strategy for targeting CLC. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

LEFTY2 Controls Migration of Human Endometrial Cancer Cells via Focal Adhesion Kinase Activity (FAK) and miRNA-200a.

Science.gov (United States)

Alowayed, Nour; Salker, Madhuri S; Zeng, Ni; Singh, Yogesh; Lang, Florian

2016-01-01

LEFTY2, a suppressor of cell proliferation, tumor growth, regulator of stemness and embryonic differentiation, is a negative regulator of cancer cell reprogramming. Malignant transformation may lead to migration requiring loss of adhesion and gain of migratory activity. Signaling involved in the orchestration of migration, proliferation and spreading of cells include focal adhesion kinase (FAK) and adhesion molecule E-cadherin. The present study explored whether LEFTY2 influences the proliferation marker MKi67, FAK activity, E-cadherin abundance and migration of Ishikawa human endometrial carcinoma cells. Moreover, the study explored the involvement of microRNA-200a (miR-200a), which is known to regulate cellular adhesion by targeting E-Cadherin. FAK activity was estimated from FAK phosphorylation quantified by Western blotting, migration utilizing a wound healing assay, miR-200a and MKi67 expression levels utilizing qRT-PCR, cell proliferation and apoptosis using BrdU and Annexin V staining, respectively, and E-Cadherin (E-Cad) abundance, using confocal microscopy. LEFTY2 (25 ng/ml, 48 hours) treatment was followed by decrease of MKi67 expression, FAK activity and migration. LEFTY2 upregulated miRNA-200a and E-Cad protein level in Ishikawa cells. The effect of LEFTY2 on migration was mimicked by FAK inhibitor PF 573228 (50 µM). Addition of LEFTY2 in the presence of PF-573228 did not result in a further significant decline of migration. In conclusion, LEFTY2 down-regulates MKi67 expression and FAK activity, up-regulates miR-200a and E-cadherin, and is thus a powerful negative regulator of endometrial cell proliferation and migration. © 2016 The Author(s) Published by S. Karger AG, Basel.

Acetaldehyde dissociates the PTP1B–E-cadherin–β-catenin complex in Caco-2 cell monolayers by a phosphorylation-dependent mechanism

Science.gov (United States)

Sheth, Parimal; Seth, Ankur; Atkinson, Katherine J.; Gheyi, Tarun; Kale, Gautam; Giorgianni, Francesco; Desiderio, Dominic M.; Li, Chunying; Naren, Anjaparavanda; Rao, Radhakrishna

2006-01-01

Interactions between E-cadherin, β-catenin and PTP1B (protein tyrosine phosphatase 1B) are crucial for the organization of AJs (adherens junctions) and epithelial cell–cell adhesion. In the present study, the effect of acetaldehyde on the AJs and on the interactions between E-cadherin, β-catenin and PTP1B was determined in Caco-2 cell monolayers. Treatment of cell monolayers with acetaldehyde induced redistribution of E-cadherin and β-catenin from the intercellular junctions by a tyrosine phosphorylation-dependent mechanism. The PTPase activity associated with E-cadherin and β-catenin was significantly reduced and the interaction of PTP1B with E-cadherin and β-catenin was attenuated by acetaldehyde. Acetaldehyde treatment resulted in phosphorylation of β-catenin on tyrosine residues, and abolished the interaction of β-catenin with E-cadherin by a tyrosine kinase-dependent mechanism. Protein binding studies showed that the treatment of cells with acetaldehyde reduced the binding of β-catenin to the C-terminal region of E-cadherin. Pairwise binding studies using purified proteins indicated that the direct interaction between E-cadherin and β-catenin was reduced by tyrosine phosphorylation of β-catenin, but was unaffected by tyrosine phosphorylation of E-cadherin-C. Treatment of cells with acetaldehyde also reduced the binding of E-cadherin to GST (glutathione S-transferase)–PTP1B. The pairwise binding study showed that GST–E-cadherin-C binds to recombinant PTP1B, but this binding was significantly reduced by tyrosine phosphorylation of E-cadherin. Acetaldehyde increased the phosphorylation of β-catenin on Tyr-331, Tyr-333, Tyr-654 and Tyr-670. These results show that acetaldehyde induces disruption of interactions between E-cadherin, β-catenin and PTP1B by a phosphorylation-dependent mechanism. PMID:17087658

The effect of chemo-embolization on E-cadherin expression of primary hepatocellular carcinoma

International Nuclear Information System (INIS)

Xiao Enhua; Hu Guodong; Liu Pengcheng; Hu Daoyu; Liu Shaochun; Hao Chunrong

2001-01-01

Objective: To study the significance of E-cadherin (E-cad) expression of primary hepatocellular carcinoma (PHC), and the effect of the different chemo-embolization treatment on E-cad. Methods:Ninety-eight histopathological verified PHC specimens were obtained. The patients were treated with surgical resection alone (57 cases), and second stage surgical resection after four kinds of chemo-embolization (41 cases). Strept avidin-biotin complex (SABC) immunohistochemical staining with monoclonal antibody against human E-cad was used to observe the E-cad in all specimens. The experimental results were compared with the surgical and clinical findings. Results: The metastatic rates in E-cad (+) and (-) were 43.3%, 70.4% respectively (x 2 = 4.22, P 0.05). The E-cad expression of trabecular and clear cell PHC was higher than that of solid and poorly differentiated PHC. After chemo-embolization, the E-cad expression of the former decreased, the latter increased. The E-cad expression decreased as pathologic grades increasing. After chemo-embolization, the E-cad expression increased as pathological grades increasing. The metastatic rates in interventional group and surgical resection alone were 48.8%, 56.1% respectively (P > 0.05). Conclusions: The increased expression of E-cad would restrain PHC from metastasis. It could act as a prognosis-predictive marker. The effect of chemo-embolization on E-cadherin expression of primary hepatocellular carcinoma had histopathologic difference

Surface functionalization of inorganic nano-crystals with fibronectin and E-cadherin chimera synergistically accelerates trans-gene delivery into embryonic stem cells

International Nuclear Information System (INIS)

Kutsuzawa, K.; Chowdhury, E.H.; Nagaoka, M.; Maruyama, K.; Akiyama, Y.; Akaike, T.

2006-01-01

Stem cells holding great promises in regenerative medicine have the potential to be differentiated to a specific cell type through genetic manipulation. However, conventional ways of gene transfer to such progenitor cells suffer from a number of disadvantages particularly involving safety and efficacy issues. Here, we report on the development of a bio-functionalized inorganic nano-carrier of DNA by embedding fibronectin and E-cadherin chimera on the carrier, leading to its high affinity interactions with embryonic stem cell surface and accelerated trans-gene delivery for subsequent expression. While only apatite nano-particles were very inefficient in transfecting embryonic stem cells, fibronectin-anchored particles and to a more significant extent, fibronectin and E-cadherin-Fc-associated particles dramatically enhanced trans-gene delivery with a value notably higher than that of commercially available lipofection system. The involvement of both cell surface integrin and E-cadherin in mediating intracellular localization of the hybrid carrier was verified by blocking integrin binding site with excess free fibronectin and up-regulating both integrin and E-cadherin through PKC activation. Thus, the new establishment of a bio-functional hybrid gene-carrier would promote and facilitate development of stem cell-based therapy in regenerative medicine

Mammary-specific inactivation of E-cadherin and p53 impairs functional gland development and leads to pleomorphic invasive lobular carcinoma in mice

Directory of Open Access Journals (Sweden)

Patrick W. B. Derksen

2011-05-01

Breast cancer is the most common malignancy in women of the Western world. Even though a large percentage of breast cancer patients show pathological complete remission after standard treatment regimes, approximately 30–40% are non-responsive and ultimately develop metastatic disease. To generate a good preclinical model of invasive breast cancer, we have taken a tissue-specific approach to somatically inactivate p53 and E-cadherin, the cardinal cell-cell adhesion receptor that is strongly associated with tumor invasiveness. In breast cancer, E-cadherin is found mutated or otherwise functionally silenced in invasive lobular carcinoma (ILC, which accounts for 10–15% of all breast cancers. We show that mammary-specific stochastic inactivation of conditional E-cadherin and p53 results in impaired mammary gland function during pregnancy through the induction of anoikis resistance of mammary epithelium, resulting in loss of epithelial organization and a dysfunctional mammary gland. Moreover, combined inactivation of E-cadherin and p53 induced lactation-independent development of invasive and metastatic mammary carcinomas, which showed strong resemblance to human pleomorphic ILC. Dissemination patterns of mouse ILC mimic the human malignancy, showing metastasis to the gastrointestinal tract, peritoneum, lung, lymph nodes and bone. Our results confirm that loss of E-cadherin contributes to both mammary tumor initiation and metastasis, and establish a preclinical mouse model of human ILC that can be used for the development of novel intervention strategies to treat invasive breast cancer.

O-GlcNAcylation affects β-catenin and E-cadherin expression, cell motility and tumorigenicity of colorectal cancer.

Science.gov (United States)

Harosh-Davidovich, Shani Ben; Khalaila, Isam

2018-03-01

O-GlcNAcylation, the addition of β-N-acetylglucosamine (O-GlcNAc) moiety to Ser/Thr residues, is a sensor of the cell metabolic state. Cancer diseases such as colon, lung and breast cancer, possess deregulated O-GlcNAcylation. Studies during the last decade revealed that O-GlcNAcylation is implicated in cancer tumorigenesis and proliferation. The Wnt/β-catenin signaling pathway and cadherin-mediated adhesion are also implicated in epithelial-mesenchymal transition (EMT), a key cellular process in invasion and cancer metastasis. Often, deregulation of the Wnt pathway is caused by altered phosphorylation of its components. Specifically, phosphorylation of Ser or Thr residues of β-catenin affects its location and interaction with E-cadherin, thus facilitating cell-cell adhesion. Consistent with previous studies, the current study indicates that β-catenin is O-GlcNAcylated. To test the effect of O-GlcNAcylation on cell motility and how O-GlcNAcylation might affect β-catenin and E-cadherin functions, the enzyme machinery of O-GlcNAcylation was modulated either with chemical inhibitors or by gene silencing. When O-GlcNAcase (OGA) was inhibited, a global elevation of protein O-GlcNAcylation and increase in the expression of E-cadherin and β-catenin were noted. Concomitantly with enhanced O-GlcNAcylation, β-catenin transcriptional activity were elevated. Additionally, fibroblast cell motility was enhanced. Stable silenced cell lines with adenoviral OGA or adenoviral O-GlcNAc transferase (OGT) were established. Consistent with the results obtained by OGA chemical inhibition by TMG, OGT-silencing led to a significant reduction in β-catenin level. In vivo, murine orthotropic colorectal cancer model indicates that elevated O-GlcNAcylation leads to increased mortality rate, tumor and metastasis development. However, reduction in O-GlcNAcylation promoted survival that could be attributed to attenuated tumor and metastasis development. The results described herein provide

Expression of cadherin and NCAM in human small cell lung cancer cell lines and xenografts

DEFF Research Database (Denmark)

Rygaard, K; Møller, C; Bock, E

1992-01-01

characterised, the cadherin family and the Ig superfamily member, neural cell adhesion molecule (NCAM). We investigated expression of these two adhesion molecule families in small cell lung cancer (SCLC) cell lines and xenografts by immunoblotting. Nineteen tumours established from 15 patients with SCLC were......Tumour cell adhesion, detachment and aggregation seem to play an important part in tumour invasion and metastasis, and numerous cell adhesion molecules are expressed by tumour cells. Several families of cell-cell adhesion molecules have been described, of which two groups are particularly well...... embryonic development, which may play a role in connection with tumour invasion and metastasis, was found in 14/18 NCAM expressing SCLC tumours. Individual tumours grown as cell lines and as nude mouse xenografts showed no qualitative differences in cadherin or NCAM expression....

N-Cadherin Maintains the Healthy Biology of Nucleus Pulposus Cells under High-Magnitude Compression.

Science.gov (United States)

Wang, Zhenyu; Leng, Jiali; Zhao, Yuguang; Yu, Dehai; Xu, Feng; Song, Qingxu; Qu, Zhigang; Zhuang, Xinming; Liu, Yi

2017-01-01

Mechanical load can regulate disc nucleus pulposus (NP) biology in terms of cell viability, matrix homeostasis and cell phenotype. N-cadherin (N-CDH) is a molecular marker of NP cells. This study investigated the role of N-CDH in maintaining NP cell phenotype, NP matrix synthesis and NP cell viability under high-magnitude compression. Rat NP cells seeded on scaffolds were perfusion-cultured using a self-developed perfusion bioreactor for 5 days. NP cell biology in terms of cell apoptosis, matrix biosynthesis and cell phenotype was studied after the cells were subjected to different compressive magnitudes (low- and high-magnitudes: 2% and 20% compressive deformation, respectively). Non-loaded NP cells were used as controls. Lentivirus-mediated N-CDH overexpression was used to further investigate the role of N-CDH under high-magnitude compression. The 20% deformation compression condition significantly decreased N-CDH expression compared with the 2% deformation compression and control conditions. Meanwhile, 20% deformation compression increased the number of apoptotic NP cells, up-regulated the expression of Bax and cleaved-caspase-3 and down-regulated the expression of Bcl-2, matrix macromolecules (aggrecan and collagen II) and NP cell markers (glypican-3, CAXII and keratin-19) compared with 2% deformation compression. Additionally, N-CDH overexpression attenuated the effects of 20% deformation compression on NP cell biology in relation to the designated parameters. N-CDH helps to restore the cell viability, matrix biosynthesis and cellular phenotype of NP cells under high-magnitude compression. © 2017 The Author(s). Published by S. Karger AG, Basel.

Simulation platform for direct load control of household appliances. Literature survey and G2 implementation

Energy Technology Data Exchange (ETDEWEB)

Kolm, J; Vlaheli, A

1996-10-01

There is an incentive for the power utilities to look for other ways than building new power stations to satisfy increasing customer power needs. One way to fulfill this demand is by redistributing the available electric power between the different power consumers. This method can successfully be used during high peak hours. The utility is also able to make financial profits selling the redistributed electric power at a higher price to customers with temporary high power demands. Direct Load Control - DLC, a Demand Side Management - DSM tool, is one way to achieve a redistribution of electric power. This masters thesis project consisted in developing a user-friendly simulation platform for domestic appliances combined with an electric power control system to be employed for Direct Load Control. The platform contains the necessary facilities for designing an electrical distribution network model and is implemented in G2, an object-oriented real-time environment. The final application provides an on-line instrument for the utility to control the power consumption over the entire system in terms of dispensing power in an electrical network. The report consists of two main parts. The first part describes a literature survey we systematically compiled to gather literature sources. The second part outlines our design and implementation of the G2 simulation platform for a water-heater model with a Direct Load Control system. The entire simulation platform is designed to allow a flexible change and improvement of the different models. Consequently, our software is a powerful tool for studying a wide range of problems related to a Load Management program involving electrical household loads. 9 refs, 32 figs

A direct CO2 control system for ocean acidification experiments: testing effects on the coralline red algae Phymatolithon lusitanicum

Directory of Open Access Journals (Sweden)

Laura Sordo

2016-09-01

Full Text Available Most ocean acidification (OA experimental systems rely on pH as an indirect way to control CO2. However, accurate pH measurements are difficult to obtain and shifts in temperature and/or salinity alter the relationship between pH and pCO2. Here we describe a system in which the target pCO2 is controlled via direct analysis of pCO2 in seawater. This direct type of control accommodates potential temperature and salinity shifts, as the target variable is directly measured instead of being estimated. Water in a header tank is permanently re-circulated through an air-water equilibrator. The equilibrated air is then routed to an infrared gas analyzer (IRGA that measures pCO2 and conveys this value to a Proportional-Integral-Derivative (PID controller. The controller commands a solenoid valve that opens and closes the CO2 flush that is bubbled into the header tank. This low-cost control system allows the maintenance of stabilized levels of pCO2 for extended periods of time ensuring accurate experimental conditions. This system was used to study the long term effect of OA on the coralline red algae Phymatolithon lusitanicum. We found that after 11 months of high CO2 exposure, photosynthesis increased with CO2 as opposed to respiration, which was positively affected by temperature. Results showed that this system is adequate to run long-term OA experiments and can be easily adapted to test other relevant variables simultaneously with CO2, such as temperature, irradiance and nutrients.

Combined overexpression of cadherin 6, cadherin 11 and cluster of differentiation 44 is associated with lymph node metastasis and poor prognosis in oral squamous cell carcinoma.

Science.gov (United States)

Ma, Chao; Zhao, Ji-Zhi; Lin, Run-Tai; Zhou, Lian; Chen, Yong-Ning; Yu, Li-Jiang; Shi, Tian-Yin; Wang, Mu; Liu, Man-Man; Liu, Yao-Ran; Zhang, Tao

2018-06-01

Oral squamous cell carcinoma (OSCC) is a highly invasive lesion that frequently metastasizes to the cervical lymph nodes and is associated with a poor prognosis. Several adhesion factors, including cadherin 6 (CDH6), cadherin 11 (CDH11) and cluster of differentiation 44 (CD44), have been reported to be involved in the invasion and metastasis of multiple types of cancer. Therefore, the aim of the present study was to determine the expression of CDH6, CDH11 and CD44 in tumor tissues from patients with OSCC, and whether this was associated with the metastasis and survival of OSCC. The mRNA expression of the human tumor metastasis-related cytokines was examined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in OSCC tumors with or without lymph node metastasis (n=10/group). The expression of CDH6, CDH11 and CD44 in 101 OSCC and 10 normal oral mucosa samples was examined by immunohistochemical staining. The association between overall and disease-specific survival times of patients with OSCC and the expression of these three proteins was evaluated using Kaplan-Meier curves and the log-rank test. RT-qPCR results indicated that the mRNA expression of CDH6, CDH11 and CD44 was increased in OSCC patients with lymph node metastasis (2.93-, 2.01- and 1.92-fold; P<0.05). Overexpression of CDH6, CDH11 and CD44 was observed in 31/35 (89%), 25/35 (71%) and 31/35 (89%) patients, respectively. The number of OSCC patients with lymph node metastasis exhibiting CDH6, CDH11 and CD44 overexpression was significantly higher than the number of patients without lymph node metastasis exhibiting overexpression of these proteins (P=0.017, P=0.038 and P=0.007, respectively). OSCC patients with high co-expression of CDH6, CDH11 and CD44 exhibited lower disease-specific survival times (P=0.047; χ 2 =3.933) when compared with OSCC patients with low co-expression of these adhesion factors. CDH6, CDH11 and CD44 serve important roles in OSCC metastasis and the combined use

Loss of cadherin-based cell adhesion and the progression of Invasive Lobular Breast Cancer

NARCIS (Netherlands)

Vlug, E.J.

2015-01-01

Lobular breast cancer is a type of breast cancer that is histologically characterized by a noncohesive growth pattern of small regular cells, where single cells infiltrate as one-layered strands of cells. This noncohesive growth pattern is due to inactivation of the E-cadherin complex and a

Targeting and crossing of the human maternofetal barrier by Listeria monocytogenes: role of internalin interaction with trophoblast E-cadherin.

Science.gov (United States)

Lecuit, Marc; Nelson, D Michael; Smith, Steve D; Khun, Huot; Huerre, Michel; Vacher-Lavenu, Marie-Cécile; Gordon, Jeffrey I; Cossart, Pascale

2004-04-20

Listeria monocytogenes produces severe fetoplacental infections in humans. How it targets and crosses the maternofetal barrier is unknown. We used immunohistochemistry to examine the location of L. monocytogenes in placental and amniotic tissue samples obtained from women with fetoplacental listeriosis. The results raised the possibility that L. monocytogenes crosses the maternofetal barrier through the villous syncytiotrophoblast, with secondary infection occurring via the amniotic epithelium. Because epidemiological studies indicate that the bacterial surface protein, internalin (InlA), may play a role in human fetoplacental listeriosis, we investigated the cellular patterns of expression of its host receptor, E-cadherin, at the maternofetal interface. E-cadherin was found on the basal and apical plasma membranes of syncytiotrophoblasts and in villous cytotrophoblasts. Established trophoblastic cell lines, primary trophoblast cultures, and placental villous explants were each exposed to isogenic InlA+ or InlA- strains of L. monocytogenes, and to L. innocua expressing or not InlA. Quantitative assays of cellular invasion demonstrated that bacterial entry into syncytiotrophoblasts occurs via the apical membrane in an InlA-E-cadherin dependent manner. In human placental villous explants, bacterial invasion of the syncytiotrophoblast barrier and underlying villous tissue and subsequent replication produces histopathological lesions that mimic those seen in placentas of women with listeriosis. Thus, the InlA-E-cadherin interaction that plays a key role in the crossing of the intestinal barrier in humans is also exploited by L. monocytogenes to target and cross the placental barrier. Such a ligand-receptor interaction allowing a pathogen to specifically cross the placental villous trophoblast barrier has not been reported previously.

Cadherin-Catenin Complex Dissociation in Lobular Neoplasia of the Breast

Science.gov (United States)

Morrogh, Mary; Andrade, Victor P.; Giri, Dilip; Sakr, Rita A.; Paik, Wooyul; Qin, Li-Xuan; Arroyo, Crispinita D.; Brogi, Edi; Morrow, Monica; King, Tari A.

2015-01-01

Background E-cadherin (E-CD) inactivation with loss of E-CD-mediated cell adhesion is the hallmark of lesions of the lobular phenotype. E-CD is typically absent by immunohistochemistry in both lobular carcinoma in situ (LCIS) and invasive lobular lesions, suggesting it occurs early in the neoplastic process. In laboratory models, downstream post-transcriptional modifiers such as TWIST and SNAIL contribute to the dissociation of the intracellular component of the cadherin-catenin complex (CCC), resulting in tumor progression and invasion. We hypothesized that complete CCC dissociation may play a role in lobular neoplasia progression. Here we explore the relationship between loss of E-CD and dissociation of the CCC in pure LCIS and LCIS associated with invasive cancer. Methods Fresh-frozen tissues were obtained from 36 patients undergoing mastectomy for pure LCIS (n=11), LCIS with ILC (n=18) or LCIS with IDC (n=7). Individual lesions were subject to laser-capture microdissection and gene-expression analysis (Affymetrix HG-U133A 2.0). Immunohistochemistry for ER,PR,HER2, E-CD,N-CD,α-,β-, and phosphoβ-catenin, TWIST, and SNAIL were evaluated in normal, in situ, and invasive components from matched formalin-fixed paraffin-embedded samples(n=36). CCC-dissociation was defined as negative membranous E-CD, α- and β-catenin expression. Results E-CD was negative in all LCIS and ILC lesions, and positive in all normal and IDC lesions. Membranous α and β-catenin expression decreased with the transition from LCIS to ILC (pure LCIS 82%;LCIS w/ILC 28%;ILC 0%), while TWIST expression increased (pure LCIS low;LCIS w/ILC moderate;ILC high). Gene expression paralleled IHC staining patterns with a stepwise downregulation of E-CD, α and β-catenin from normal to LCIS to invasive lesions, and increasing expression of TWIST from normal to LCIS to ILC. Conclusions Loss of E-CD expression is an early event in lobular neoplasia. Decreasing membranous catenin expression in tandem with

Differential protection of Cry1Fa toxin against Spodoptera frugiperda larval gut proteases by cadherin orthologs correlates with increased synergism.

Science.gov (United States)

Rahman, Khalidur; Abdullah, Mohd Amir F; Ambati, Suresh; Taylor, Milton D; Adang, Michael J

2012-01-01

The Cry proteins produced by Bacillus thuringiensis (Bt) are the most widely used biopesticides effective against a range of crop pests and disease vectors. Like chemical pesticides, development of resistance is the primary threat to the long-term efficacy of Bt toxins. Recently discovered cadherin-based Bt Cry synergists showed the potential to augment resistance management by improving efficacy of Cry toxins. However, the mode of action of Bt Cry synergists is thus far unclear. Here we elucidate the mechanism of cadherin-based Cry toxin synergism utilizing two cadherin peptides, Spodoptera frugiperda Cad (SfCad) and Manduca sexta Cad (MsCad), which differentially enhance Cry1Fa toxicity to Spodoptera frugiperda neonates. We show that differential SfCad- and MsCad-mediated protection of Cry1Fa toxin in the Spodoptera frugiperda midgut correlates with differential Cry1Fa toxicity enhancement. Both peptides exhibited high affinity for Cry1Fa toxin and an increased rate of Cry1Fa-induced pore formation in S. frugiperda. However, only SfCad bound the S. frugiperda brush border membrane vesicle and more effectively prolonged the stability of Cry1Fa toxin in the gut, explaining higher Cry1Fa enhancement by this peptide. This study shows that cadherin fragments may enhance B. thuringiensis toxicity by at least two different mechanisms or a combination thereof: (i) protection of Cry toxin from protease degradation in the insect midgut and (ii) enhancement of pore-forming ability of Cry toxin.

E-cadherin acts as a regulator of transcripts associated with a wide range of cellular processes in mouse embryonic stem cells.

Directory of Open Access Journals (Sweden)

Francesca Soncin

Full Text Available We have recently shown that expression of the cell adhesion molecule E-cadherin is required for LIF-dependent pluripotency of mouse embryonic stem (ES cells.In this study, we have assessed global transcript expression in E-cadherin null (Ecad-/- ES cells cultured in either the presence or absence of LIF and compared these to the parental cell line wtD3.We show that LIF has little effect on the transcript profile of Ecad-/- ES cells, with statistically significant transcript alterations observed only for Sp8 and Stat3. Comparison of Ecad-/- and wtD3 ES cells cultured in LIF demonstrated significant alterations in the transcript profile, with effects not only confined to cell adhesion and motility but also affecting, for example, primary metabolic processes, catabolism and genes associated with apoptosis. Ecad-/- ES cells share similar, although not identical, gene expression profiles to epiblast-derived pluripotent stem cells, suggesting that E-cadherin expression may inhibit inner cell mass to epiblast transition. We further show that Ecad-/- ES cells maintain a functional β-catenin pool that is able to induce β-catenin/TCF-mediated transactivation but, contrary to previous findings, do not display endogenous β-catenin/TCF-mediated transactivation. We conclude that loss of E-cadherin in mouse ES cells leads to significant transcript alterations independently of β-catenin/TCF transactivation.

New insights into the molecular mechanism of E-cadherin-mediated cell adhesion by free energy calculations

DEFF Research Database (Denmark)

Doro, Fabio; Saladino, Giorgio; Belvisi, Laura

2015-01-01

Three-dimensional domain swapping is an important mode of protein association leading to the formation of stable dimers. Monomers associating via this mechanism mutually exchange a domain to form a homodimer. Classical cadherins, an increasingly important target for anticancer therapy, use domain...... swapping to mediate cell adhesion. However, despite its importance, the molecular mechanism of domain swapping is still debated. Here, we study the conformational changes that lead to activation and dimerization via domain swapping of E-cadherin. Using state-of-the-art enhanced sampling atomistic......" mechanism in which monomers in an active conformational state bind to form a homodimer, analogous to the conformational selection mechanism often observed in ligand-target binding. Moreover, we find that the open state population is increased in the presence of calcium ions at the extracellular boundary...

Epigenetic change in e-cardherin and COX-2 to predict chronic periodontitis

Directory of Open Access Journals (Sweden)

Wang Min

2010-11-01

Full Text Available Abstract Background DNA methylation of certain genes frequently occurs in neoplastic cells. Although the cause remains unknown, many genes have been identified with such atypical methylation in neoplastic cells. The hypermethylation of E-Cadherin and Cyclooxygenase 2 (COX-2 in chronic inflammation such as chronic periodontitis may demonstrate mild lesion/mutation epigenetic level. This study compares the hypermethylation status of E-Cadherin and COX-2 genes which are often found in breast cancer patients with that in chronic periodontitis. Methods Total DNA was extracted from the blood samples of 108 systemically healthy non-periodontitis subjects, and the gingival tissues and blood samples of 110 chronic periodontitis patient as well as neoplastic tissues of 106 breast cancer patients. Methylation-specific PCR for E-Cadherin and COX-2 was performed on these samples and the PCR products were analyzed on 2% agarose gel. Results Hypermethylation of E-Cadherin and COX-2 was observed in 38% and 35% of the breast cancer samples, respectively. In chronic periodontitis patients the detection rate was 25% and 19% respectively, and none was found in the systemically healthy non-periodontitis control subjects. The hypermethylation status was shown to be correlated among the three groups with statistical significance (p Conclusions This set of data shows that the epigenetic change in E-Cadherin and Cyclooxygenase-2 is associated with chronic periodontitis. The epigenetic changes presented in chronic inflammation patients might demonstrate an irreversible destruction in the tissues or organs similar to the effects of cancer. Chronic periodontitis to some extent might be associated with DNA hypermethylation which is related to cancer risk factors.

Expression of Cry1Ac toxin-binding region in Plutella xyllostella cadherin-like receptor and studying their interaction mode by molecular docking and site-directed mutagenesis.

Science.gov (United States)

Hu, Xiaodan; Zhang, Xiao; Zhong, Jianfeng; Liu, Yuan; Zhang, Cunzheng; Xie, Yajing; Lin, Manman; Xu, Chongxin; Lu, Lina; Zhu, Qing; Liu, Xianjin

2018-05-01

Cadherin-like protein has been identified as the primary Bacillus thuringiensis (Bt) Cry toxin receptor in Lepidoptera pests and plays a key role in Cry toxin insecticidal. In this study, we successfully expressed the putative Cry1Ac toxin-binding region (CR7-CR11) of Plutella xylostella cadherin-like in Escherichia coli BL21 (DE3). The expressed CR7-CR11 fragment showed binding ability to Cry1Ac toxin under denaturing (Ligand blot) and non-denaturing (ELISA) conditions. The three-dimensional structure of CR7-CR11 was constructed by homology modeling. Molecular docking results of CR7-CR11 and Cry1Ac showed that domain II and domain III of Cry1Ac were taking part in binding to CR7-CR11, while CR7-CR8 was the region of CR7-CR11 in interacting with Cry1Ac. The interaction of toxin-receptor complex was found to arise from hydrogen bond and hydrophobic interaction. Through the computer-aided alanine mutation scanning, amino acid residues of Cry1Ac (Met341, Asn442 and Ser486) and CR7-CR11 (Asp32, Arg101 and Arg127) were predicted as the hot spot residues involved in the interaction of the toxin-receptor complex. At last, we verified the importance role of these key amino acid residues by binding assay. These results will lay a foundation for further elucidating the insecticidal mechanism of Cry toxin and enhancing Cry toxin insecticidal activity by molecular modification. Copyright © 2018 Elsevier B.V. All rights reserved.

Silver nanoparticles interact with the cell membrane and increase endothelial permeability by promoting VE-cadherin internalization

Energy Technology Data Exchange (ETDEWEB)

Sun, Xia; Shi, Junpeng; Zou, Xiaoyan; Wang, Chengcheng; Yang, Yi; Zhang, Hongwu, E-mail: hwzhang@iue.ac.cn

2016-11-05

Highlights: • Short-term exposure to AgNPs at low doses induces increase HUVECs monolayer permeability. • AgNPs interact with the cell membrane and increase endothelial permeability by promoting VE-Cadherin internalization. • Particle effect is a major factor leading to endothelial dysfunction. - Abstract: The toxicological risks of silver nanoparticles (AgNPs) have attracted widespread attention, and many studies have been published that have contributed to understanding AgNPs-induced toxicity. However, little attention has been paid to the low-dose effects of AgNPs and the related toxicological mechanism is still unclear. Here, we show that short-term exposure to AgNPs at low doses induces a substantial increase in human umbilical vein endothelial cells (HUVECs) monolayer permeability, whereas Ag ions at low doses do not induce an observable increase in monolayer permeability. This effect is independent of oxidative stress and apoptosis. Scanning electron microscopy confirms that AgNPs adhere to the cell membrane after 1 h exposure. Furthermore, adhesion of AgNPs to the cell membrane can trigger vascular endothelial (VE)-cadherin phosphorylation at Y658 followed by VE-cadherin internalization, which lead to the increase in endothelial monolayer permeability. Our data show that surface interactions of AgNPs with the cell membrane, in other words, the particle effect, is a major factor leading to endothelial dysfunction following low-dose and short-term exposure. Our findings will contribute to understanding the health effects and the toxicological mechanisms of AgNPs.

Changes of E-cadherin and á-catenin in human and mouse intestinal tumours

Czech Academy of Sciences Publication Activity Database

Šloncová, Eva; Frič, P.; Kučerová, Dana; Lojda, Z.; Tuháčková, Zdena; Sovová, Vlasta

2001-01-01

Roč. 33, č. 1 (2001), s. 13-17 ISSN 0018-2214 R&D Projects: GA ČR GV312/96/K205; GA ČR GA301/00/0269; GA MZd IZ4217 Institutional research plan: CEZ:AV0Z5052915 Keywords : E-cadherin * beta-catenin * intestinal tumours Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.169, year: 2001

CRIM1 complexes with ß-catenin and cadherins, stabilizes cell-cell junctions and is critical for neural morphogenesis.

Directory of Open Access Journals (Sweden)

Virgilio G Ponferrada

Full Text Available In multicellular organisms, morphogenesis is a highly coordinated process that requires dynamically regulated adhesion between cells. An excellent example of cellular morphogenesis is the formation of the neural tube from the flattened epithelium of the neural plate. Cysteine-rich motor neuron protein 1 (CRIM1 is a single-pass (type 1 transmembrane protein that is expressed in neural structures beginning at the neural plate stage. In the frog Xenopus laevis, loss of function studies using CRIM1 antisense morpholino oligonucleotides resulted in a failure of neural development. The CRIM1 knockdown phenotype was, in some cases, mild and resulted in perturbed neural fold morphogenesis. In severely affected embryos there was a dramatic failure of cell adhesion in the neural plate and complete absence of neural structures subsequently. Investigation of the mechanism of CRIM1 function revealed that it can form complexes with ß-catenin and cadherins, albeit indirectly, via the cytosolic domain. Consistent with this, CRIM1 knockdown resulted in diminished levels of cadherins and ß-catenin in junctional complexes in the neural plate. We conclude that CRIM1 is critical for cell-cell adhesion during neural development because it is required for the function of cadherin-dependent junctions.

Cell division orientation is coupled to cell-cell adhesion by the E-cadherin/LGN complex

NARCIS (Netherlands)

Gloerich, Martijn; Bianchini, Julie M.; Siemers, Kathleen A.; Cohen, Daniel J.; Nelson, W. James

2017-01-01

Both cell-cell adhesion and oriented cell division play prominent roles in establishing tissue architecture, but it is unclear how they might be coordinated. Here, we demonstrate that the cell-cell adhesion protein E-cadherin functions as an instructive cue for cell division orientation. This is

Soy Components Genistein and Lunasin Regulate E-Cadherin and Wnt Signaling in Mammary Epithelial Cells

Science.gov (United States)

Enhanced Wnt/beta-catenin signaling and loss of E-cadherin expression are considered hallmarks of tumorigenesis. We previously showed by microarray gene profiling that dietary intake of soy-based AIN-93G diets altered components of Wnt/beta-catenin signaling in rat mammary epithelial cells. To furth...

Direct Optimal Control of Duffing Dynamics

Science.gov (United States)

Oz, Hayrani; Ramsey, John K.

2002-01-01

The "direct control method" is a novel concept that is an attractive alternative and competitor to the differential-equation-based methods. The direct method is equally well applicable to nonlinear, linear, time-varying, and time-invariant systems. For all such systems, the method yields explicit closed-form control laws based on minimization of a quadratic control performance measure. We present an application of the direct method to the dynamics and optimal control of the Duffing system where the control performance measure is not restricted to a quadratic form and hence may include a quartic energy term. The results we present in this report also constitute further generalizations of our earlier work in "direct optimal control methodology." The approach is demonstrated for the optimal control of the Duffing equation with a softening nonlinear stiffness.

HAb18G/CD147 cell-cell contacts confer resistance of a HEK293 subpopulation to anoikis in an E-cadherin-dependent manner

Directory of Open Access Journals (Sweden)

Zhu Ping

2010-04-01

Full Text Available Abstract Background Acquisition of resistance to "anoikis" facilitates the survival of cells under independent matrix-deficient conditions, such as cells in tumor progression and the production of suspension culture cells for biomedical engineering. There is evidence suggesting that CD147, an adhesion molecule associated with survival of cells in tumor metastasis and cell-cell contacts, plays an important role in resistance to anoikis. However, information regarding the functions of CD147 in mediating cell-cell contacts and anoikis-resistance remains limited and even self-contradictory. Results An anoikis-resistant clone (HEK293ar, derived from anoikis-sensitive parental Human Embryonic Kidney 293 cells, survived anoikis by the formation of cell-cell contacts. The expression of HAb18G/CD147 (a member of the CD147 family was upregulated and the protein was located at cell-cell junctions. Upregulation of HAb18G/CD147 in suspended HEK293ar cells suppressed anoikis by mediating the formation of cell-cell adhesions. Anoikis resistance in HEK293ar cells also required E-cadherin-mediated cell-cell contacts. Knock-down of HAb18G/CD147 and E-cadherin inhibited cell-cell contacts formation and increased anoikis sensitivity respectively. When HAb18G/CD147 was downregulated, E-cadherin expression in HEK293ar cells was significantly suppressed; however, knockdown of E-cadherin by E-cadherin siRNA or blocking of E-cadherin binding activity with a specific antibody and EDTA had no significant effect on HAb18G/CD147 expression. Finally, pretreatment with LY294002, a phosphoinositide 3-kinase (PI3K/AKT inhibitor, disrupted cell-cell contacts and decreased cell number, but this was not the case in cells treated with the extracellular signal-regulated kinase (ERK inhibitor PD98059. Conclusions Our results provide new evidence that HAb18G/CD147-mediated cell-cell contact confers anoikis resistance in an E-cadherin-dependent manner; and cell-cell contact mediated

URG11 mediates hypoxia-induced epithelial-to-mesenchymal transition by modulation of E-cadherin and β-catenin

International Nuclear Information System (INIS)

Du, Rui; Huang, Chen; Bi, Qian; Zhai, Ying; Xia, Lin; Liu, Jie; Sun, Shiren; Fan, Daiming

2010-01-01

Upregulated gene 11 (URG11), recently identified as a new HBx-upregulated gene that may activate β-catenin and Wnt signaling, was found to be upregulated in a human tubule cell line under low oxygen. Here, we investigated the potential role of URG11 in hypoxia-induced renal tubular epithelial-to-mesenchymal (EMT). Overexpression of URG11 in a human proximal tubule cell line (HK2) promoted a mesenchymal phenotype accompanied by reduced expression of the epithelial marker E-cadherin and increased expression of the mesenchymal markers vimentin and α-SMA, while URG11 knockdown by siRNA effectively reversed hypoxia-induced EMT. URG11 promoted the expression of β-catenin and increased its nuclear accumulation under normoxic conditions through transactivation of the β-catenin promoter. This in turn upregulated β-catenin/T-cell factor (TCF) and its downstream effector genes, vimentin, and α-SMA. In vivo, strong expression of URG11 was observed in the tubular epithelia of 5/6-nephrectomized rats, and a Western blot analysis demonstrated a close correlation between HIF-1α and URG11 protein levels. Altogether, our results indicate that URG11 mediates hypoxia-induced EMT through the suppression of E-cadherin and the activation of the β-catenin/TCF pathway.

Cell polarity development and protein trafficking in hepatocytes lacking E-cadherin/beta-catenin-based adherens junctions

NARCIS (Netherlands)

Theard, Delphine; Steiner, Magdalena; Kalicharan, Dharamdajal; Hoekstra, Dick; van IJzendoorn, Sven C. D.

Using a mutant hepatocyte cell line in which E-cadherin and ss-catenin are completely depleted from the cell surface, and, consequently, fail to form adherens junctions, we have investigated adherens junction requirement for apical-basolateral polarity development and polarized membrane trafficking.

Low PIP4K2B expression in human breast tumors correlates with reduced patient survival: A role for PIP4K2B in the regulation of E-cadherin expression.

Science.gov (United States)

Keune, Willem-Jan; Sims, Andrew H; Jones, David R; Bultsma, Yvette; Lynch, James T; Jirström, Karin; Landberg, Goran; Divecha, Nullin

2013-12-01

Phosphatidylinositol-5-phosphate (PtdIns5P) 4-kinase β (PIP4K2B) directly regulates the levels of two important phosphoinositide second messengers, PtdIns5P and phosphatidylinositol-(4,5)-bisphosphate [PtdIns(4,5)P2]. PIP4K2B has been linked to the regulation of gene transcription, to TP53 and AKT activation, and to the regulation of cellular reactive oxygen accumulation. However, its role in human tumor development and on patient survival is not known. Here, we have interrogated the expression of PIP4K2B in a cohort (489) of patients with breast tumor using immunohistochemical staining and by a meta-analysis of gene expression profiles from 2,999 breast tumors, both with associated clinical outcome data. Low PIP4K2B expression was associated with increased tumor size, high Nottingham histological grade, Ki67 expression, and distant metastasis, whereas high PIP4K2B expression strongly associated with ERBB2 expression. Kaplan-Meier curves showed that both high and low PIP4K2B expression correlated with poorer patient survival compared with intermediate expression. In normal (MCF10A) and tumor (MCF7) breast epithelial cell lines, mimicking low PIP4K2B expression, using short hairpin RNA interference-mediated knockdown, led to a decrease in the transcription and expression of the tumor suppressor protein E-cadherin (CDH1). In MCF10A cells, knockdown of PIP4K2B enhanced TGF-β-induced epithelial to mesenchymal transition (EMT), a process required during the development of metastasis. Analysis of gene expression datasets confirmed the association between low PIP4K2B and low CDH1expression. Decreased CDH1 expression and enhancement of TGF-β-induced EMT by reduced PIP4K2B expression might, in part, explain the association between low PIP4K2B expression and poor patient survival.

A complex of α6 integrin and E-cadherin drives liver metastasis of colorectal cancer cells through hepatic angiopoietin-like 6.

Science.gov (United States)

Marchiò, Serena; Soster, Marco; Cardaci, Sabrina; Muratore, Andrea; Bartolini, Alice; Barone, Vanessa; Ribero, Dario; Monti, Maria; Bovino, Paola; Sun, Jessica; Giavazzi, Raffaella; Asioli, Sofia; Cassoni, Paola; Capussotti, Lorenzo; Pucci, Piero; Bugatti, Antonella; Rusnati, Marco; Pasqualini, Renata; Arap, Wadih; Bussolino, Federico

2012-11-01

Homing of colorectal cancer (CRC) cells to the liver is a non-random process driven by a crosstalk between tumour cells and components of the host tissue. Here we report the isolation of a liver metastasis-specific peptide ligand (CGIYRLRSC) that binds a complex of E-cadherin and α(6) integrin on the surface of CRC cells. We identify angiopoietin-like 6 protein as a peptide-mimicked natural ligand enriched in hepatic blood vessels of CRC patients. We demonstrate that an interaction between hepatic angiopoietin-like 6 and tumoural α(6) integrin/E-cadherin drives liver homing and colonization by CRC cells, and that CGIYRLRSC inhibits liver metastasis through interference with this ligand/receptor system. Our results indicate a mechanism for metastasis whereby a soluble factor accumulated in normal vessels functions as a specific ligand for circulating cancer cells. Consistently, we show that high amounts of coexpressed α(6) integrin and E-cadherin in primary tumours represent a poor prognostic factor for patients with advanced CRC. Copyright © 2012 The Authors. Published by John Wiley and Sons, Ltd on behalf of EMBO.

Correlation between E-cadherin and p120 expression in invasive ductal breast cancer with a lobular component and MRI findings.

Science.gov (United States)

El Sharouni, Mary-Ann; Postma, Emily L; van Diest, Paul J

2017-12-01

Invasive breast cancer comprises a spectrum of histological changes with purely lobular cancer on one side and purely ductal cancer on the other, with many mixed lesions in between. In a previous study, we showed that in patients with any percentage lobular component at core needle biopsy, preoperative MRI leads to the detection of clinically relevant additional findings in a substantial percentage of patients, irrespective of the percentage of the lobular component. Detection of a small lobular component may however not be reproducible among pathologists. Loss of membrane expression of E-cadherin or p120 is useful biomarkers of ILC and may therefore support a more objective diagnosis. All patients diagnosed with breast cancer containing a lobular component of any percentage between January 2008 and October 2012 were prospectively offered preoperative MRI. Clinically relevant additional findings on MRI were verified by pathology evaluation. Expression patterns of E-cadherin and p120 were evaluated by immunohistochemistry on the core needle biopsy. MRI was performed in 109 patients. The percentage of lobular component was significantly increased in cases with aberrant E-cadherin or p120 expression (both p = lobular component in the core needle of their breast cancer.

Octamer-binding protein 4 affects the cell biology and phenotypic transition of lung cancer cells involving β-catenin/E-cadherin complex degradation.

Science.gov (United States)

Chen, Zhong-Shu; Ling, Dong-Jin; Zhang, Yang-De; Feng, Jian-Xiong; Zhang, Xue-Yu; Shi, Tian-Sheng

2015-03-01

Clinical studies have reported evidence for the involvement of octamer‑binding protein 4 (Oct4) in the tumorigenicity and progression of lung cancer; however, the role of Oct4 in lung cancer cell biology in vitro and its mechanism of action remain to be elucidated. Mortality among lung cancer patients is more frequently due to metastasis rather than their primary tumors. Epithelial‑mesenchymal transition (EMT) is a prominent biological event for the induction of epithelial cancer metastasis. The aim of the present study was to investigate whether Oct4 had the capacity to induce lung cancer cell metastasis via the promoting the EMT in vitro. Moreover, the effect of Oct4 on the β‑catenin/E‑cadherin complex, associated with EMT, was examined using immunofluorescence and immunoprecipitation assays as well as western blot analysis. The results demonstrated that Oct4 enhanced cell invasion and adhesion accompanied by the downregulation of epithelial marker cytokeratin, and upregulation of the mesenchymal markers vimentin and N‑cadherin. Furthermore, Oct4 induced EMT of lung cancer cells by promoting β‑catenin/E‑cadherin complex degradation and regulating nuclear localization of β‑catenin. In conclusion, the present study indicated that Oct4 affected the cell biology of lung cancer cells in vitro through promoting lung cancer cell metastasis via EMT; in addition, the results suggested that the association and degradation of the β‑catenin/E‑cadherin complex was regulated by Oct4 during the process of EMT.

Dragon (repulsive guidance molecule RGMb) inhibits E-cadherin expression and induces apoptosis in renal tubular epithelial cells.

Science.gov (United States)

Liu, Wenjing; Li, Xiaoling; Zhao, Yueshui; Meng, Xiao-Ming; Wan, Chao; Yang, Baoxue; Lan, Hui-Yao; Lin, Herbert Y; Xia, Yin

2013-11-01

Dragon is one of the three members of the repulsive guidance molecule (RGM) family, i.e. RGMa, RGMb (Dragon), and RGMc (hemojuvelin). We previously identified the RGM members as bone morphogenetic protein (BMP) co-receptors that enhance BMP signaling. Our previous studies found that Dragon is highly expressed in the tubular epithelial cells of mouse kidneys. However, the roles of Dragon in renal epithelial cells are yet to be defined. We now show that overexpression of Dragon increased cell death induced by hypoxia in association with increased cleaved poly(ADP-ribose) polymerase and cleaved caspase-3 levels in mouse inner medullary collecting duct (IMCD3) cells. Dragon also inhibited E-cadherin expression but did not affect epithelial-to-mesenchymal transition induced by TGF-β in IMCD3 cells. Previous studies suggest that the three RGM members can function as ligands for the receptor neogenin. Interestingly, our present study demonstrates that the Dragon actions on apoptosis and E-cadherin expression in IMCD3 cells were mediated by the neogenin receptor but not through the BMP pathway. Dragon expression in the kidney was up-regulated by unilateral ureteral obstruction in mice. Compared with wild-type mice, heterozygous Dragon knock-out mice exhibited 45-66% reduction in Dragon mRNA expression, decreased epithelial apoptosis, and increased tubular E-cadherin expression and had attenuated tubular injury after unilateral ureteral obstruction. Our results suggest that Dragon may impair tubular epithelial integrity and induce epithelial apoptosis both in vitro and in vivo.

Celastrol inhibits TGF-β1-induced epithelial–mesenchymal transition by inhibiting Snail and regulating E-cadherin expression

Energy Technology Data Exchange (ETDEWEB)

Kang, Hyereen; Lee, Minjae [Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of); Jang, Sung-Wuk, E-mail: swjang@amc.seoul.kr [Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of); Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of)

2013-08-09

Highlights: •We investigated the effects of celastrol on TGF-β1-induced EMT in epithelial cells. •Celastrol regulates TGF-β1-induced morphological changes and E-cadherin expression. •Celastrol inhibits TGF-β1-induced Snail expression. •Celastrol strongly suppresses TGF-β1-induced invasion in MDCK and A549 cells. -- Abstract: The epithelial–mesenchymal transition (EMT) is a pivotal event in the invasive and metastatic potentials of cancer progression. Celastrol inhibits the proliferation of a variety of tumor cells including leukemia, glioma, prostate, and breast cancer; however, the possible role of celastrol in the EMT is unclear. We investigated the effect of celastrol on the EMT. Transforming growth factor-beta 1 (TGF-β1) induced EMT-like morphologic changes and upregulation of Snail expression. The downregulation of E-cadherin expression and upregulation of Snail in Madin–Darby Canine Kidney (MDCK) and A549 cell lines show that TGF-β1-mediated the EMT in epithelial cells; however, celastrol markedly inhibited TGF-β1-induced morphologic changes, Snail upregulation, and E-cadherin expression. Migration and invasion assays revealed that celastrol completely inhibited TGF-β1-mediated cellular migration in both cell lines. These findings indicate that celastrol downregulates Snail expression, thereby inhibiting TGF-β1-induced EMT in MDCK and A549 cells. Thus, our findings provide new evidence that celastrol suppresses lung cancer invasion and migration by inhibiting TGF-β1-induced EMT.

Colorectal signet ring cell carcinoma: Influence of EGFR, E-cadherin and MMP-13 expression on clinicopathological features and prognosis.

Science.gov (United States)

Foda, Abd Al-Rahman Mohammad; Aziz, Azza Abdel; Mohamed, Mie Ali

2018-02-01

Signet ring cell carcinoma (SRCC) is unique rare subtype of mucin-producing colorectal adenocarcinoma characterized by presence of signet ring cells, in >50% of the tumor tissue. This study aims to investigate expression of EGFR, E-cadherin and MMP-13 expression on clinicopathological features of signet ring cell type and its prognostic effect using manual tissue microarray technique. In this work, we studied tumor tissue specimens from 150 patients with colorectal cancer cases among which 19 cases of SRCC. High density manual tissue microarrays were constructed using modified mechanical pencil tips technique and immunohistochemistry for EGFR, E-cadherin and MMP-13 expression was done. We found that SRCC was significantly associated with younger age and more frequency of LN metastasis than all other groups. SRCC was also significantly associated with annular gross picture, more depth of invasion, advanced stage, more lymphovascular emboli, more perineural invasion and less arousal from an overlying adenoma. In conclusion, colorectal SRCC has distinctive clinicopathological and histological features with different unique mechanisms of carcinogenesis and more aggressive biologic behavior than other colorectal carcinoma subtypes. Negative/low expressions of EGFR and E-cadherin and MMP-13 were found in SRCC with no effect on the prognosis. Copyright © 2017 Elsevier Inc. All rights reserved.

Hyaluronan suppresses prostate tumor cell proliferation through diminished expression of N-cadherin and aberrant growth factor receptor signaling

International Nuclear Information System (INIS)

Bharadwaj, Alamelu G.; Goodrich, Nathaniel P.; McAtee, Caitlin O.; Haferbier, Katie; Oakley, Gregory G.; Wahl, James K.; Simpson, Melanie A.

2011-01-01

Hyaluronan (HA) production has been functionally implicated in prostate tumorigenesis and metastasis. We previously used prostate tumor cells overexpressing the HA synthesizing enzyme HAS3 or the clinically relevant hyaluronidase Hyal1 to show that excess HA production suppresses tumor growth, while HA turnover accelerates spontaneous metastasis from the prostate. Here, we examined pathways responsible for effects of HAS3 and Hyal1 on tumor cell phenotype. Detailed characterization of cell cycle progression revealed that expression of Hyal1 accelerated cell cycle re-entry following synchronization, whereas HAS3 alone delayed entry. Hyal1 expressing cells exhibited a significant reduction in their ability to sustain ERK phosphorylation upon stimulation by growth factors, and in their expression of the cyclin-dependent kinase inhibitor p21. In contrast, HAS3 expressing cells showed prolonged ERK phosphorylation and increased expression of both p21 and p27, in asynchronous and synchronized cultures. Changes in cell cycle regulatory proteins were accompanied by HA-induced suppression of N-cadherin, while E-cadherin expression and β-catenin expression and distribution remained unchanged. Our results are consistent with a model in which excess HA synthesis suppresses cell proliferation by promoting homotypic E-cadherin mediated cell-cell adhesion, consequently signaling to elevate cell cycle inhibitor expression and suppress G1- to S-phase transition.

Downregulation and Mutation of a Cadherin Gene Associated with Cry1Ac Resistance in the Asian Corn Borer, Ostrinia furnacalis (Guenée

Directory of Open Access Journals (Sweden)

Tingting Jin

2014-09-01

Full Text Available Development of resistance in target pests is a major threat to long-term use of transgenic crops expressing Bacillus thuringiensis (Bt Cry toxins. To manage and/or delay the evolution of resistance in target insects through the implementation of effective strategies, it is essential to understand the basis of resistance. One of the most important mechanisms of insect resistance to Bt crops is the alteration of the interactions between Cry toxins and their receptors in the midgut. A Cry1Ac-selected strain of Asian corn borer (ACB, Ostrinia furnacalis, a key pest of maize in China, evolved three mutant alleles of a cadherin-like protein (OfCAD (MPR-r1, MPR-r2 and MPR-r3, which mapped within the toxin-binding region (TBR. Each of the three mutant alleles possessed two or three amino acid substitutions in this region, especially Thr1457→Ser. In highly resistant larvae (ACB-Ac200, MPR-r2 had a 26-amino acid residue deletion in the TBR, which resulted in reduced binding of Cry1Ac compared to the MPR from the susceptible strain, suggesting that the number of amino acid deletions influences the level of resistance. Furthermore, downregulation of OfCAD gene (ofcad transcription was observed in the Cry1Ac resistant strain, ACB-Ac24, suggesting that Cry1Ac resistance in ACB is associated with the downregulation of the transcript levels of the cadherin-like protein gene. The OfCAD identified from ACB exhibited a high degree of similarity to other members of the cadherin super-family in lepidopteran species.

Global methylation silencing of clustered proto-cadherin genes in cervical cancer: serving as diagnostic markers comparable to HPV

International Nuclear Information System (INIS)

Wang, Kai-Hung; Lin, Cuei-Jyuan; Liu, Chou-Jen; Liu, Dai-Wei; Huang, Rui-Lan; Ding, Dah-Ching; Weng, Ching-Feng; Chu, Tang-Yuan

2015-01-01

Epigenetic remodeling of cell adhesion genes is a common phenomenon in cancer invasion. This study aims to investigate global methylation of cell adhesion genes in cervical carcinogenesis and to apply them in early detection of cancer from cervical scraping. Genome-wide methylation array was performed on an investigation cohort, including 16 cervical intraepithelial neoplasia 3 (CIN3) and 20 cervical cancers (CA) versus 12 each of normal, inflammation and CIN1 as controls. Twelve members of clustered proto-cadherin (PCDH) genes were collectively methylated and silenced, which were validated in cancer cells of the cervix, endometrium, liver, head and neck, breast, and lung. In an independent cohort including 107 controls, 66 CIN1, 85 CIN2/3, and 38 CA, methylated PCDHA4 and PCDHA13 were detected in 2.8%, 24.2%, 52.9%, and 84.2% (P < 10 −25 ), and 2.8%, 24.2%, 50.6%, and 94.7% (P < 10 −29 ), respectively. In diagnosis of CIN2 or more severe lesion of the cervix, a combination test of methylated PCDHA4 or PCDHA13 from cervical scraping had a sensitivity, specificity, positive predictive value, and negative predictive value of 74.8%, 80.3%, 73%, and 81.8%, respectively. Testing of this combination from cervical scraping is equally sensitive but more specific than human papillomavirus (HPV) test in diagnosis of CIN2 or more severe lesions. The study disclosed a collective methylation of PCDH genes in cancer of cervix and other sites. At least two of them can be promising diagnostic markers for cervical cancer noninferior to HPV

New Fluorescent Reporter Systems for Evaluation of the Expression of E- and N-Cadherins.

Science.gov (United States)

Burmistrova, O A; Nikulin, S V; Zakharova, G S; Fomicheva, K A; Alekseev, B Ya; Shkurnikov, M Yu

2018-05-24

During metastatic growth, cells of solid tumors undergo phenotypical changes related to epithelial-mesenchymal transition. Epithelial-mesenchymal transition is regarded as a potential target for prospective antitumor drugs. Fluorescent reporter systems for evaluation of the expression of markers of epithelial and mesenchymal status (E- and N-cadherins) were created. The described approaches can be used for creation of analogous reporter systems.

Usher syndrome type 1-associated cadherins shape the photoreceptor outer segment.

Science.gov (United States)

Schietroma, Cataldo; Parain, Karine; Estivalet, Amrit; Aghaie, Asadollah; Boutet de Monvel, Jacques; Picaud, Serge; Sahel, José-Alain; Perron, Muriel; El-Amraoui, Aziz; Petit, Christine

2017-06-05

Usher syndrome type 1 (USH1) causes combined hearing and sight defects, but how mutations in USH1 genes lead to retinal dystrophy in patients remains elusive. The USH1 protein complex is associated with calyceal processes, which are microvilli of unknown function surrounding the base of the photoreceptor outer segment. We show that in Xenopus tropicalis , these processes are connected to the outer-segment membrane by links composed of protocadherin-15 (USH1F protein). Protocadherin-15 deficiency, obtained by a knockdown approach, leads to impaired photoreceptor function and abnormally shaped photoreceptor outer segments. Rod basal outer disks displayed excessive outgrowth, and cone outer segments were curved, with lamellae of heterogeneous sizes, defects also observed upon knockdown of Cdh23 , encoding cadherin-23 (USH1D protein). The calyceal processes were virtually absent in cones and displayed markedly reduced F-actin content in rods, suggesting that protocadherin-15-containing links are essential for their development and/or maintenance. We propose that calyceal processes, together with their associated links, control the sizing of rod disks and cone lamellae throughout their daily renewal. © 2017 Schietroma et al.

VE-cadherin Y685F knock-in mouse is sensitive to vascular permeability in recurrent angiogenic organs.

Science.gov (United States)

Sidibé, Adama; Polena, Helena; Pernet-Gallay, Karin; Razanajatovo, Jeremy; Mannic, Tiphaine; Chaumontel, Nicolas; Bama, Soumalamaya; Maréchal, Irène; Huber, Philippe; Gulino-Debrac, Danielle; Bouillet, Laurence; Vilgrain, Isabelle

2014-08-01

Covalent modifications such as tyrosine phosphorylation are associated with the breakdown of endothelial cell junctions and increased vascular permeability. We previously showed that vascular endothelial (VE)-cadherin was tyrosine phosphorylated in vivo in the mouse reproductive tract and that Y685 was a target site for Src in response to vascular endothelial growth factor in vitro. In the present study, we aimed to understand the implication of VE-cadherin phosphorylation at site Y685 in cyclic angiogenic organs. To achieve this aim, we generated a knock-in mouse carrying a tyrosine-to-phenylalanine point mutation of VE-cadherin Y685 (VE-Y685F). Although homozygous VE-Y685F mice were viable and fertile, the nulliparous knock-in female mice exhibited enlarged uteri with edema. This phenotype was observed in 30% of females between 4 to 14 mo old. Histological examination of longitudinal sections of the VE-Y685F uterus showed an extensive disorganization of myometrium and endometrium with highly edematous uterine glands, numerous areas with sparse cells, and increased accumulation of collagen fibers around blood vessels, indicating a fibrotic state. Analysis of cross section of ovaries showed the appearance of spontaneous cysts, which suggested increased vascular hyperpermeability. Electron microscopy analysis of capillaries in the ovary showed a slight but significant increase in the gap size between two adjacent endothelial cell membranes in the junctions of VE-Y685F mice (wild-type, 11.5 ± 0.3, n = 78; and VE-Y685F, 12.48 ± 0.3, n = 65; P = 0.045), as well as collagen fiber accumulation around capillaries. Miles assay revealed that either basal or vascular endothelial growth factor-stimulated permeability in the skin was increased in VE-Y685F mice. Since edema and fibrotic appearance have been identified as hallmarks of initial increased vascular permeability, we conclude that the site Y685 in VE-cadherin is involved in the physiological regulation of capillary

Discovery of an O-mannosylation pathway selectively serving cadherins and protocadherins

DEFF Research Database (Denmark)

Larsen, Ida Signe Bohse; Narimatsu, Yoshiki; Joshi, Hiren Jitendra

2017-01-01

The cadherin (cdh) superfamily of adhesion molecules carry O-linked mannose (O-Man) glycans at highly conserved sites localized to specific β-strands of their extracellular cdh (EC) domains. These O-Man glycans do not appear to be elongated like O-Man glycans found on α-dystroglycan (α-DG), and we...... recently demonstrated that initiation of cdh/protocadherin (pcdh) O-Man glycosylation is not dependent on the evolutionary conserved POMT1/POMT2 enzymes that initiate O-Man glycosylation on α-DG. Here, we used a CRISPR/Cas9 genetic dissection strategy combined with sensitive and quantitative O-Man...... glycoproteomics to identify a homologous family of four putative protein O-mannosyltransferases encoded by the TMTC1-4 genes, which were found to be imperative for cdh and pcdh O-Man glycosylation. KO of all four TMTC genes in HEK293 cells resulted in specific loss of cdh and pcdh O-Man glycosylation, whereas...

A Regulatory Network Involving β-Catenin, e-Cadherin, PI3k/Akt, and Slug Balances Self-Renewal and Differentiation of Human Pluripotent Stem Cells In Response to Wnt Signaling.

Science.gov (United States)

Huang, Tyng-Shyan; Li, Li; Moalim-Nour, Lilian; Jia, Deyong; Bai, Jian; Yao, Zemin; Bennett, Steffany A L; Figeys, Daniel; Wang, Lisheng

2015-05-01

The mechanisms underlying disparate roles of the canonical Wnt signaling pathway in maintaining self-renewal or inducing differentiation and lineage specification in embryonic stem cells (ESCs) are not clear. In this study, we provide the first demonstration that self-renewal versus differentiation of human ESCs (hESCs) in response to Wnt signaling is predominantly determined by a two-layer regulatory circuit involving β-catenin, E-cadherin, PI3K/Akt, and Slug in a time-dependent manner. Short-term upregulation of β-catenin does not lead to the activation of T-cell factor (TCF)-eGFP Wnt reporter in hESCs. Instead, it enhances E-cadherin expression on the cell membrane, thereby enhancing hESC self-renewal through E-cadherin-associated PI3K/Akt signaling. Conversely, long-term Wnt activation or loss of E-cadherin intracellular β-catenin binding domain induces TCF-eGFP activity and promotes hESC differentiation through β-catenin-induced upregulation of Slug. Enhanced expression of Slug leads to a further reduction of E-cadherin that serves as a β-catenin "sink" sequestering free cytoplasmic β-catenin. The formation of such a framework reinforces hESCs to switch from a state of temporal self-renewal associated with short-term Wnt/β-catenin activation to definitive differentiation. Stem Cells 2015;33:1419-1433. © 2015 AlphaMed Press.

Dragon (Repulsive Guidance Molecule RGMb) Inhibits E-cadherin Expression and Induces Apoptosis in Renal Tubular Epithelial Cells*

Science.gov (United States)

Liu, Wenjing; Li, Xiaoling; Zhao, Yueshui; Meng, Xiao-Ming; Wan, Chao; Yang, Baoxue; Lan, Hui-Yao; Lin, Herbert Y.; Xia, Yin

2013-01-01

Dragon is one of the three members of the repulsive guidance molecule (RGM) family, i.e. RGMa, RGMb (Dragon), and RGMc (hemojuvelin). We previously identified the RGM members as bone morphogenetic protein (BMP) co-receptors that enhance BMP signaling. Our previous studies found that Dragon is highly expressed in the tubular epithelial cells of mouse kidneys. However, the roles of Dragon in renal epithelial cells are yet to be defined. We now show that overexpression of Dragon increased cell death induced by hypoxia in association with increased cleaved poly(ADP-ribose) polymerase and cleaved caspase-3 levels in mouse inner medullary collecting duct (IMCD3) cells. Dragon also inhibited E-cadherin expression but did not affect epithelial-to-mesenchymal transition induced by TGF-β in IMCD3 cells. Previous studies suggest that the three RGM members can function as ligands for the receptor neogenin. Interestingly, our present study demonstrates that the Dragon actions on apoptosis and E-cadherin expression in IMCD3 cells were mediated by the neogenin receptor but not through the BMP pathway. Dragon expression in the kidney was up-regulated by unilateral ureteral obstruction in mice. Compared with wild-type mice, heterozygous Dragon knock-out mice exhibited 45–66% reduction in Dragon mRNA expression, decreased epithelial apoptosis, and increased tubular E-cadherin expression and had attenuated tubular injury after unilateral ureteral obstruction. Our results suggest that Dragon may impair tubular epithelial integrity and induce epithelial apoptosis both in vitro and in vivo. PMID:24052264

Dithiolethione modified valproate and diclofenac increase E-cadherin expression and decrease proliferation of non-small cell lung cancer cells.

Science.gov (United States)

Moody, Terry W; Switzer, Christopher; Santana-Flores, Wilmarie; Ridnour, Lisa A; Berna, Marc; Thill, Michelle; Jensen, Robert T; Sparatore, Anna; Del Soldato, Piero; Yeh, Grace C; Roberts, David D; Giaccone, Giuseppe; Wink, David A

2010-05-01

The effects of dithiolethione modified valproate, diclofenac and sulindac on non-small cell lung cancer (NSCLC) cells were investigated. Sulfur(S)-valproate and S-diclofenac at 1 microg/ml concentrations significantly reduced prostaglandin (PG)E(2) levels in NSCLC cell lines A549 and NCI-H1299 as did the COX-2 inhibitor DuP-697. In vitro, S-valproate, S-diclofenac and S-sulindac half-maximally inhibited the clonal growth of NCI-H1299 cells at 6, 6 and 15 microg/ml, respectively. Using the MTT assay, 10 microg/ml S-valproate, NO-aspirin and Cay10404, a selective COX-2 inhibitor, but not SC-560, a selective COX-1 inhibitor, inhibited the growth of A549 cells. In vivo, 18mg/kg i.p. of S-valproate and S-diclofenac, but not S-sulindac, significantly inhibited A549 or NCI-H1299 xenograft proliferation in nude mice, but had no effect on the nude mouse body weight. The mechanism by which S-valproate and S-diclofenac inhibited the growth of NSCLC cells was investigated. Nitric oxide-aspirin but not S-valproate caused apoptosis of NSCLC cells. By Western blot, S-valproate and S-diclofenac increased E-cadherin but reduced vimentin and ZEB1 (a transcriptional suppressor of E-cadherin) protein expression in NSCLC cells. Because S-valproate and S-diclofenac inhibit the growth of NSCLC cells and reduce PGE(2) levels, they may prove beneficial in the chemoprevention and/or therapy of NSCLC. Published by Elsevier Ireland Ltd.

Comparison between iterative wavefront control algorithm and direct gradient wavefront control algorithm for adaptive optics system

International Nuclear Information System (INIS)

Cheng Sheng-Yi; Liu Wen-Jin; Chen Shan-Qiu; Dong Li-Zhi; Yang Ping; Xu Bing

2015-01-01

Among all kinds of wavefront control algorithms in adaptive optics systems, the direct gradient wavefront control algorithm is the most widespread and common method. This control algorithm obtains the actuator voltages directly from wavefront slopes through pre-measuring the relational matrix between deformable mirror actuators and Hartmann wavefront sensor with perfect real-time characteristic and stability. However, with increasing the number of sub-apertures in wavefront sensor and deformable mirror actuators of adaptive optics systems, the matrix operation in direct gradient algorithm takes too much time, which becomes a major factor influencing control effect of adaptive optics systems. In this paper we apply an iterative wavefront control algorithm to high-resolution adaptive optics systems, in which the voltages of each actuator are obtained through iteration arithmetic, which gains great advantage in calculation and storage. For AO system with thousands of actuators, the computational complexity estimate is about O(n 2 ) ∼ O(n 3 ) in direct gradient wavefront control algorithm, while the computational complexity estimate in iterative wavefront control algorithm is about O(n) ∼ (O(n) 3/2 ), in which n is the number of actuators of AO system. And the more the numbers of sub-apertures and deformable mirror actuators, the more significant advantage the iterative wavefront control algorithm exhibits. (paper)

Normal endometrial stromal cells regulate 17β-estradiol-induced epithelial-mesenchymal transition via slug and E-cadherin in endometrial adenocarcinoma cells in vitro.

Science.gov (United States)

Zhang, Hui; Li, Hongyan; Qi, Shasha; Liu, Zhao; Fu, Yibing; Li, Mingjiang; Zhao, Xingbo

2017-01-01

Stroma-tumor communication participates in the pathogenesis of endometrial carcinomas. In previous studies, we found that normal stromal cells inhibited the growth of endometrial carcinoma cells. Here, we investigated the role of normal stromal cells in the epithelial-mesenchymal transition (EMT) of endometrial carcinoma cells and explored the possible mechanism implied. We found that conditioned medium (CM) by normal endometrial stromal cells (NSC) reduced cell growth and induced cell apoptosis in Ishikawa cells. CM by NSC inhibited 17β-estradiol-induced cell growth and apoptosis decrease in Ishikawa cells. Moreover, CM by NSC inhibited the migration and invasion, and 17β-estradiol-induced migration and invasion in Ishikawa cells. Meanwhile, CM by NSC decreased Slug expression and 17β-estradiol-induced Slug expression, increased E-cadherin expression and abolished 17β-estradiol-induced E-cadherin reduction in Ishikawa cells. In conclusion, normal stromal factors can inhibit 17β-estradiol-induced cell proliferation and apoptosis inhibition, and abolished 17β-estradiol-induced EMT in endometrial cancer cell via regulating E-cadherin and Slug expression.

Pathologically decreased expression of miR-193a contributes to metastasis by targeting WT1-E-cadherin axis in non-small cell lung cancers

Directory of Open Access Journals (Sweden)

Junjie Chen

2016-11-01

Full Text Available Abstract Background The metastatic cascade is a complex and multistep process with many potential barriers. Recently, miR-193a has been reported to be a suppressive miRNA in multiple types of cancers, but its underlying anti-oncogenic activity in non-small cell lung cancers (NSCLC is not fully elucidated. Methods The expressions of miR-193a (miR-193a-5p in human lung cancer tissues and cell lines were detected by real-time PCR. Dual-luciferase reporter assay was used to identify the direct target of miR-193a. Cell proliferation, apoptosis, and metastasis were assessed by CCK-8, flow cytometry, and Transwell assay, respectively. Results The expression of miR-193a in lung cancer tissues was decreased comparing to adjacent non-tumor tissues due to DNA hypermethylation in lung cancer tissues. Ectopic expression of miR-193a inhibited cell proliferation, colony formation, migration, and invasion in A549 and H1299 cells. Moreover, overexpression of miR-193a partially reversed tumor growth factor-β1 (TGF-β1-induced epithelial-to-mesenchymal transition (EMT in NSCLC cells. Mechanistically, miR-193a reduced the expression of WT1, which negatively regulated the protein level of E-cadherin, suggesting that miR-193a might prevent EMT via modulating WT1-E-cadherin axis. Importantly, knockdown of WT1 resembled the anti-cancer activity by miR-193a and overexpression of WT1 partially reversed miR-193a-induced anti-cancer activity, indicating that WT1 plays an important role in miR-193a-induced anti-cancer activity. Finally, overexpression of miR-193a decreased the growth of tumor xenografts in mice. Conclusion Collectively, our results have revealed an important role of miR-193a-WT1-E-cadherin axis in metastasis, demonstrated an important molecular cue for EMT, and suggested a therapeutic strategy of restoring miR-193a expression in NSCLC.

Comparison between iterative wavefront control algorithm and direct gradient wavefront control algorithm for adaptive optics system

Science.gov (United States)

Cheng, Sheng-Yi; Liu, Wen-Jin; Chen, Shan-Qiu; Dong, Li-Zhi; Yang, Ping; Xu, Bing

2015-08-01

Among all kinds of wavefront control algorithms in adaptive optics systems, the direct gradient wavefront control algorithm is the most widespread and common method. This control algorithm obtains the actuator voltages directly from wavefront slopes through pre-measuring the relational matrix between deformable mirror actuators and Hartmann wavefront sensor with perfect real-time characteristic and stability. However, with increasing the number of sub-apertures in wavefront sensor and deformable mirror actuators of adaptive optics systems, the matrix operation in direct gradient algorithm takes too much time, which becomes a major factor influencing control effect of adaptive optics systems. In this paper we apply an iterative wavefront control algorithm to high-resolution adaptive optics systems, in which the voltages of each actuator are obtained through iteration arithmetic, which gains great advantage in calculation and storage. For AO system with thousands of actuators, the computational complexity estimate is about O(n2) ˜ O(n3) in direct gradient wavefront control algorithm, while the computational complexity estimate in iterative wavefront control algorithm is about O(n) ˜ (O(n)3/2), in which n is the number of actuators of AO system. And the more the numbers of sub-apertures and deformable mirror actuators, the more significant advantage the iterative wavefront control algorithm exhibits. Project supported by the National Key Scientific and Research Equipment Development Project of China (Grant No. ZDYZ2013-2), the National Natural Science Foundation of China (Grant No. 11173008), and the Sichuan Provincial Outstanding Youth Academic Technology Leaders Program, China (Grant No. 2012JQ0012).

Robust design of a 2-DOF GMV controller: a direct self-tuning and fuzzy scheduling approach.

Science.gov (United States)

Silveira, Antonio S; Rodríguez, Jaime E N; Coelho, Antonio A R

2012-01-01

This paper presents a study on self-tuning control strategies with generalized minimum variance control in a fixed two degree of freedom structure-or simply GMV2DOF-within two adaptive perspectives. One, from the process model point of view, using a recursive least squares estimator algorithm for direct self-tuning design, and another, using a Mamdani fuzzy GMV2DOF parameters scheduling technique based on analytical and physical interpretations from robustness analysis of the system. Both strategies are assessed by simulation and real plants experimentation environments composed of a damped pendulum and an under development wind tunnel from the Department of Automation and Systems of the Federal University of Santa Catarina. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

Usher syndrome type 1–associated cadherins shape the photoreceptor outer segment

Science.gov (United States)

Parain, Karine; Aghaie, Asadollah; Picaud, Serge

2017-01-01

Usher syndrome type 1 (USH1) causes combined hearing and sight defects, but how mutations in USH1 genes lead to retinal dystrophy in patients remains elusive. The USH1 protein complex is associated with calyceal processes, which are microvilli of unknown function surrounding the base of the photoreceptor outer segment. We show that in Xenopus tropicalis, these processes are connected to the outer-segment membrane by links composed of protocadherin-15 (USH1F protein). Protocadherin-15 deficiency, obtained by a knockdown approach, leads to impaired photoreceptor function and abnormally shaped photoreceptor outer segments. Rod basal outer disks displayed excessive outgrowth, and cone outer segments were curved, with lamellae of heterogeneous sizes, defects also observed upon knockdown of Cdh23, encoding cadherin-23 (USH1D protein). The calyceal processes were virtually absent in cones and displayed markedly reduced F-actin content in rods, suggesting that protocadherin-15–containing links are essential for their development and/or maintenance. We propose that calyceal processes, together with their associated links, control the sizing of rod disks and cone lamellae throughout their daily renewal. PMID:28495838

Correlação entre as expressões de P-caderina e de receptores de estrógeno no câncer da mama Correlation between P-cadherin and estrogen receptor expression in breast cancer

Directory of Open Access Journals (Sweden)

Joana Cancela de Amorim Falcão Paredes

2002-01-01

Full Text Available Introdução: A manutenção da arquitetura dos tecidos adultos depende essencialmente da integridade estrutural e funcional das caderinas, uma superfamília de moléculas de adesão celular dependentes de cálcio, que medeiam normalmente a adesão intercelular homofílica e homotípica. A P-caderina é expressa pelas células mioepiteliais da glândula mamária normal, sendo aberrantemente expressa num pequeno subgrupo de carcinomas da mama. Vários estudos recentes têm demonstrado que a expressão desta proteína está significativamente correlacionada com tumores de alto grau histológico e negativos para os receptores de estrógeno (RE. Objetivos: Investigar a expressão da P-caderina e dos receptores de estrógeno (RE em carcinomas da mama invasivos e correlacionar os resultados obtidos. Material e método: O padrão de expressão da P-caderina e dos RE foi estudado imunoistoquimicamente em 149 carcinomas invasivos da mama; seguidamente, correlacionou-se estatisticamente a expressão destas duas proteínas. Resultados: A P-caderina foi detectada nas células mioepiteliais do tecido mamário normal e em 46 de 146 (31,5% casos de carcinoma invasivo da mama. A expressão da P-caderina correlacionou-se inversamente com a expressão dos RE, verificando-se que o subgrupo de tumores P-caderina positivos e RE negativos apresentava alto grau histológico e maior agressividade tumoral. Conclusão: Demonstrou-se que a P-caderina identifica um subgrupo de carcinomas da mama, que não expressa RE e que parece representar um estado mais avançado da progressão tumoral. Estes resultados levantam ainda a hipótese de que a expressão desta proteína possa ser regulada por uma via alternativa, independente de estrógeno.Background: The maintenance of adult tissue architecture largely depends on structural and functional integrity of cadherins, a superfamily of Ca2+-dependent cell-cell adhesion molecules that usually mediate homophilic and homotypic

Glycogen Synthase Kinase 3 (GSK-3) influences epithelial barrier function by regulating Occludin, Claudin-1 and E-cadherin expression

International Nuclear Information System (INIS)

Severson, Eric A.; Kwon, Mike; Hilgarth, Roland S.; Parkos, Charles A.; Nusrat, Asma

2010-01-01

The Apical Junctional Complex (AJC) encompassing the tight junction (TJ) and adherens junction (AJ) plays a pivotal role in regulating epithelial barrier function and epithelial cell proliferative processes through signaling events that remain poorly characterized. A potential regulator of AJC protein expression is Glycogen Synthase Kinase-3 (GSK-3). GSK-3 is a constitutively active kinase that is repressed during epithelial-mesenchymal transition (EMT). In the present study, we report that GSK-3 activity regulates the structure and function of the AJC in polarized model intestinal (SK-CO15) and kidney (Madin-Darby Canine Kidney (MDCK)) epithelial cells. Reduction of GSK-3 activity, either by small molecule inhibitors or siRNA targeting GSK-3 alpha and beta mRNA, resulted in increased permeability to both ions and bulk solutes. Immunofluorescence labeling and immunoblot analyses revealed that the barrier defects correlated with decreased protein expression of AJC transmembrane proteins Occludin, Claudin-1 and E-cadherin without influencing other TJ proteins, Zonula Occludens-1 (ZO-1) and Junctional Adhesion Molecule A (JAM-A). The decrease in Occludin and E-cadherin protein expression correlated with downregulation of the corresponding mRNA levels for these respective proteins following GSK-3 inhibition. These observations implicate an important role of GSK-3 in the regulation of the structure and function of the AJC that is mediated by differential modulation of mRNA transcription of key AJC proteins, Occludin, Claudin-1 and E-cadherin.

Sodium Solute Symporter and Cadherin Proteins Act as Bacillus thuringiensis Cry3Ba Toxin Functional Receptors in Tribolium castaneum*

Science.gov (United States)

Contreras, Estefanía; Schoppmeier, Michael; Real, M. Dolores; Rausell, Carolina

2013-01-01

Understanding how Bacillus thuringiensis (Bt) toxins interact with proteins in the midgut of susceptible coleopteran insects is crucial to fully explain the molecular bases of Bt specificity and insecticidal action. In this work, aminopeptidase N (TcAPN-I), E-cadherin (TcCad1), and sodium solute symporter (TcSSS) have been identified by ligand blot as putative Cry3Ba toxin-binding proteins in Tribolium castaneum (Tc) larvae. RNA interference knockdown of TcCad1 or TcSSS proteins resulted in decreased susceptibility to Cry3Ba toxin, demonstrating the Cry toxin receptor functionality for these proteins. In contrast, TcAPN-I silencing had no effect on Cry3Ba larval toxicity, suggesting that this protein is not relevant in the Cry3Ba toxin mode of action in Tc. Remarkable features of TcSSS protein were the presence of cadherin repeats in its amino acid sequence and that a TcSSS peptide fragment containing a sequence homologous to a binding epitope found in Manduca sexta and Tenebrio molitor Bt cadherin functional receptors enhanced Cry3Ba toxicity. This is the first time that the involvement of a sodium solute symporter protein as a Bt functional receptor has been demonstrated. The role of this novel receptor in Bt toxicity against coleopteran insects together with the lack of receptor functionality of aminopeptidase N proteins might account for some of the differences in toxin specificity between Lepidoptera and Coleoptera insect orders. PMID:23645668

Glycogen Synthase Kinase 3 (GSK-3) influences epithelial barrier function by regulating Occludin, Claudin-1 and E-cadherin expression

Energy Technology Data Exchange (ETDEWEB)

Severson, Eric A.; Kwon, Mike; Hilgarth, Roland S.; Parkos, Charles A. [Epithelial Pathobiology Research Unit, Dept. of Pathology, Emory University, Atlanta, GA 30322 (United States); Nusrat, Asma, E-mail: anusrat@emory.edu [Epithelial Pathobiology Research Unit, Dept. of Pathology, Emory University, Atlanta, GA 30322 (United States)

2010-07-02

The Apical Junctional Complex (AJC) encompassing the tight junction (TJ) and adherens junction (AJ) plays a pivotal role in regulating epithelial barrier function and epithelial cell proliferative processes through signaling events that remain poorly characterized. A potential regulator of AJC protein expression is Glycogen Synthase Kinase-3 (GSK-3). GSK-3 is a constitutively active kinase that is repressed during epithelial-mesenchymal transition (EMT). In the present study, we report that GSK-3 activity regulates the structure and function of the AJC in polarized model intestinal (SK-CO15) and kidney (Madin-Darby Canine Kidney (MDCK)) epithelial cells. Reduction of GSK-3 activity, either by small molecule inhibitors or siRNA targeting GSK-3 alpha and beta mRNA, resulted in increased permeability to both ions and bulk solutes. Immunofluorescence labeling and immunoblot analyses revealed that the barrier defects correlated with decreased protein expression of AJC transmembrane proteins Occludin, Claudin-1 and E-cadherin without influencing other TJ proteins, Zonula Occludens-1 (ZO-1) and Junctional Adhesion Molecule A (JAM-A). The decrease in Occludin and E-cadherin protein expression correlated with downregulation of the corresponding mRNA levels for these respective proteins following GSK-3 inhibition. These observations implicate an important role of GSK-3 in the regulation of the structure and function of the AJC that is mediated by differential modulation of mRNA transcription of key AJC proteins, Occludin, Claudin-1 and E-cadherin.

Expression and function of the atypical cadherin FAT1 in chronic liver disease

International Nuclear Information System (INIS)

Valletta, Daniela; Czech, Barbara; Thasler, Wolfgang E.; Müller, Martina; Bosserhoff, Anja-Katrin; Hellerbrand, Claus

2012-01-01

Highlights: ► The expression of the atypical cadherin FAT1 is increased in chronic liver disease. ► FAT1 expression goes up during the activation of hepatic stellate cells (HSCs). ► Activated HSCs are the cellular source of enhanced FAT1 expression in diseased livers. ► FAT1 enhanced NFkB activity and resistance to apoptosis in activated HSCs. ► FAT1 is a new therapeutic target for prevention and treatment of hepatic fibrosis. -- Abstract: Hepatic fibrosis can be considered as wound healing process in response to hepatocellular injury. Activation of hepatic stellate cells (HSCs) is a key event of hepatic fibrosis since activated HSCs are the cellular source of enhanced extracellular matrix deposition, and reversion of liver fibrosis is accompanied by clearance of activated HSCs by apoptosis. The atypical cadherin FAT1 has been shown to regulate diverse biological functions as cell proliferation and planar cell polarity, and also to affect wound healing. Here, we found increased FAT1 expression in different murine models of chronic liver injury and in cirrhotic livers of patients with different liver disease. Also in hepatic tissue of patients with non-alcoholic steatohepatitis FAT1 expression was significantly enhanced and correlated with collagen alpha I(1) expression. Immunohistochemistry revealed no significant differences in staining intensity between hepatocytes in normal and cirrhotic liver tissue but myofibroblast like cells in fibrotic septa of cirrhotic livers showed a prominent immunosignal. Furthermore, FAT1 mRNA and protein expression markedly increased during in vitro activation of primary human and murine HSCs. Together, these data indicated activated HSCs as cellular source of enhanced FAT1 expression in diseased livers. To gain insight into the functional role of FAT1 in activated HSCs we suppressed FAT1 in these cells by siRNA. We newly found that FAT1 suppression in activated HSCs caused a downregulation of NFκB activity. This

Expression and function of the atypical cadherin FAT1 in chronic liver disease

Energy Technology Data Exchange (ETDEWEB)

Valletta, Daniela; Czech, Barbara [Department of Internal Medicine I, University Hospital Regensburg, Regensburg (Germany); Thasler, Wolfgang E. [Grosshadern Tissue Bank and Center for Liver Cell Research, Department of Surgery, Ludwig-Maximilians-University Munich (Germany); Mueller, Martina [Department of Internal Medicine I, University Hospital Regensburg, Regensburg (Germany); Bosserhoff, Anja-Katrin [Institute of Pathology, University of Regensburg, Regensburg (Germany); Hellerbrand, Claus, E-mail: claus.hellerbrand@ukr.de [Department of Internal Medicine I, University Hospital Regensburg, Regensburg (Germany)

2012-09-28

Highlights: Black-Right-Pointing-Pointer The expression of the atypical cadherin FAT1 is increased in chronic liver disease. Black-Right-Pointing-Pointer FAT1 expression goes up during the activation of hepatic stellate cells (HSCs). Black-Right-Pointing-Pointer Activated HSCs are the cellular source of enhanced FAT1 expression in diseased livers. Black-Right-Pointing-Pointer FAT1 enhanced NFkB activity and resistance to apoptosis in activated HSCs. Black-Right-Pointing-Pointer FAT1 is a new therapeutic target for prevention and treatment of hepatic fibrosis. -- Abstract: Hepatic fibrosis can be considered as wound healing process in response to hepatocellular injury. Activation of hepatic stellate cells (HSCs) is a key event of hepatic fibrosis since activated HSCs are the cellular source of enhanced extracellular matrix deposition, and reversion of liver fibrosis is accompanied by clearance of activated HSCs by apoptosis. The atypical cadherin FAT1 has been shown to regulate diverse biological functions as cell proliferation and planar cell polarity, and also to affect wound healing. Here, we found increased FAT1 expression in different murine models of chronic liver injury and in cirrhotic livers of patients with different liver disease. Also in hepatic tissue of patients with non-alcoholic steatohepatitis FAT1 expression was significantly enhanced and correlated with collagen alpha I(1) expression. Immunohistochemistry revealed no significant differences in staining intensity between hepatocytes in normal and cirrhotic liver tissue but myofibroblast like cells in fibrotic septa of cirrhotic livers showed a prominent immunosignal. Furthermore, FAT1 mRNA and protein expression markedly increased during in vitro activation of primary human and murine HSCs. Together, these data indicated activated HSCs as cellular source of enhanced FAT1 expression in diseased livers. To gain insight into the functional role of FAT1 in activated HSCs we suppressed FAT1 in these

Brain Metastases from Lung Cancer Show Increased Expression of DVL1, DVL3 and Beta-Catenin and Down-Regulation of E-Cadherin

Directory of Open Access Journals (Sweden)

Anja Kafka

2014-06-01

Full Text Available The susceptibility of brain to secondary formation from lung cancer primaries is a well-known phenomenon. In contrast, the molecular basis for invasion and metastasis to the brain is largely unknown. In the present study, 31 brain metastases that originated from primary lung carcinomas were analyzed regarding over expression of Dishevelled-1 (DVL1, Dishevelled-3 (DVL3, E-cadherin (CDH1 and beta-catenin (CTNNB1. Protein expressions and localizations were analyzed by immunohistochemistry. Genetic alterations of E-cadherin were tested by polymerase chain reaction (PCR/loss of heterozygosity (LOH. Heteroduplex was used to investigate mutations in beta-catenin. DVL1 and DVL3 showed over expression in brain metastasis in 87.1% and 90.3% of samples respectively. Nuclear staining was observed in 54.8% of cases for DVL1 and 53.3% for DVL3. The main effector of the Wnt signaling, beta-catenin, was up-regulated in 56%, and transferred to the nucleus in 36% of metastases. When DVL1 and DVL3 were up-regulated the number of cases with nuclear beta-catenin significantly increased (p = 0.0001. Down-regulation of E-cadherin was observed in 80% of samples. Genetic analysis showed 36% of samples with LOH of the CDH1. In comparison to other lung cancer pathologies, the diagnoses adenocarcinoma and small cell lung cancer (SCLC were significantly associated to CDH1 LOH (p = 0.001. Microsatellite instability was detected in one metastasis from adenocarcinoma. Exon 3 of beta-catenin was not targeted. Altered expression of Dishevelled-1, Dishevelled-3, E-cadherin and beta-catenin were present in brain metastases which indicates that Wnt signaling is important and may contribute to better understanding of genetic profile conditioning lung cancer metastasis to the brain.

Induction machine Direct Torque Control system based on fuzzy adaptive control

Science.gov (United States)

Li, Shi-ping; Yu, Yan; Jiao, Zhen-gang; Gu, Shu-sheng

2009-07-01

Direct Torque Control technology is a high-performance communication control method, it uses the space voltage vector method, and then to the inverter switch state control, to obtain high torque dynamic performance. But none of the switching states is able to generate the exact voltage vector to produce the desired changes in torque and flux in most of the switching instances. This causes a high ripple in torque. To solve this problem, a fuzzy implementation of Direct Torque Control of Induction machine is presented here. Error of stator flux, error of motor electromagnetic torque and position of angle of flux are taken as fuzzy variables. In order to further solve nonlinear problem of variation parameters in direct torque control system, the paper proposes a fuzzy parameter PID adaptive control method which is suitable for the direct torque control of an asynchronous motor. The generation of its fuzzy control is obtained by analyzing and optimizing PID control step response and combining expert's experience. For this reason, it carries out fuzzy work to PID regulator of motor speed to achieve to regulate PID parameters. Therefore the control system gets swifter response velocity, stronger robustness and higher precision of velocity control. The computer simulated results verify the validity of this novel method.

Identification of Bacillus thuringiensis Cry3Aa toxin domain II loop 1 as the binding site of Tenebrio molitor cadherin repeat CR12.

Science.gov (United States)

Zúñiga-Navarrete, Fernando; Gómez, Isabel; Peña, Guadalupe; Amaro, Itzel; Ortíz, Ernesto; Becerril, Baltazar; Ibarra, Jorge E; Bravo, Alejandra; Soberón, Mario

2015-04-01

Bacillus thuringiensis Cry toxins exert their toxic effect by specific recognition of larval midgut proteins leading to oligomerization of the toxin, membrane insertion and pore formation. The exposed domain II loop regions of Cry toxins have been shown to be involved in receptor binding. Insect cadherins have shown to be functionally involved in toxin binding facilitating toxin oligomerization. Here, we isolated a VHH (VHHA5) antibody by phage display that binds Cry3Aa loop 1 and competed with the binding of Cry3Aa to Tenebrio molitor brush border membranes. VHHA5 also competed with the binding of Cry3Aa to a cadherin fragment (CR12) that was previously shown to be involved in binding and toxicity of Cry3Aa, indicating that Cry3Aa binds CR12 through domain II loop 1. Moreover, we show that a loop 1 mutant, previously characterized to have increased toxicity to T. molitor, displayed a correlative enhanced binding affinity to T. molitor CR12 and to VHHA5. These results show that Cry3Aa domain II loop 1 is a binding site of CR12 T. molitor cadherin. Copyright © 2015 Elsevier Ltd. All rights reserved.

Lysophosphatidic acid modulates the association of PTP1B with N-cadherin/catenin complex in SKOV3 ovarian cancer cells.

Science.gov (United States)

Huang, Ruby Yun-Ju; Wen, Chen-Chen; Liao, Chih-Kai; Wang, Shu-Huei; Chou, Liang-Yin; Wu, Jiahn-Chun

2012-09-01

LPA (lysophosphatidic acid) is a natural phospholipid that plays important roles in promoting cancer cell proliferation, invasion and metastases. We previously reported that LPA induces ovarian cancer cell dispersal and disruption of AJ (adherens junction) through the activation of SFK (Src family kinases). In this study, we have investigated the regulatory mechanisms during the early phase of LPA-induced cell dispersal. An in vitro model of the ovarian cancer cell line SKOV3 for cell dispersal was used. LPA induces rapid AJ disruption by increasing the internalization of N-cadherin-β-catenin. By using immunoprecipitations, LPA was shown to induce increased tyrosine phosphorylation of β-catenin and alter the balance of β-catenin-bound SFK and PTP1B (phosphotyrosine phosphatase 1B). The altered balance of tyrosine kinase/phosphatase correlated with a concomitant disintegration of the β-catenin-α-catenin, but not the β-catenin-N-cadherin complex. This disintegration of β-catenin from α-catenin and the cell dispersal caused by LPA can be rescued by blocking SFK activity with the chemical inhibitor, PP2. More importantly, PP2 also restores the level of PTP1B bound to β-catenin. We propose that LPA signalling alters AJ stability by changing the dynamics of tyrosine kinase/phosphatase bound to AJ proteins. This work provides further understanding of the early signalling events regulating ovarian cancer cell dispersal and AJ disruption induced by LPA. © The Author(s) Journal compilation © 2012 International Federation for Cell Biology.

Nuclear translocation of β-catenin and decreased expression of epithelial cadherin in human papillomavirus-positive tonsillar cancer: an early event in human papillomavirus-related tumour progression?

Science.gov (United States)

Stenner, Markus; Yosef, Basima; Huebbers, Christian U; Preuss, Simon F; Dienes, Hans-Peter; Speel, Ernst-Jan M; Odenthal, Margarete; Klussmann, Jens P

2011-06-01

High-risk human papillomaviruses (HPVs) constitute an important risk factor for tonsillar cancer. This study describes changes in cell adhesion molecules during metastasis of HPV-related and HPV-unrelated tonsillar carcinomas. We examined 48 primary tonsillar carcinoma samples (25 HPV-16 DNA-positive, 23 HPV-16 DNA-negative) and their respective lymph node metastases for their HPV status and for the expression of p16, epithelial cadherin (E-cadherin), β-catenin, and vimentin. A positive HPV-specific polymerase chain reaction finding correlated significantly with p16 overexpression in both primary tumours and their metastases (P<0.0001 for both). In HPV-unrelated carcinomas, the expression of E-cadherin was significantly lower in metastases than in primary tumours (P<0.001). In contrast, the expression of nuclear β-catenin was significantly higher in metastases than in primary tumours (P=0.016). In HPV-related carcinomas, nuclear localization of β-catenin expression was already apparent in primary tumours (P=0.030). The expression of vimentin significantly correlated with the grading of the primary tumour (P=0.021). Our data indicate that the down-regulation of E-cadherin and the up-regulation of nuclear β-catenin expression might be crucial steps during tumour progression of tonsillar carcinomas, being already present in primary tumours in HPV-driven carcinomas, but becoming apparent in HPV-unrelated tumours later in the process of metastasis. © 2011 Blackwell Publishing Limited.

EXPRESSION OF E-CADHERIN AND WNT PATHWAY PROTEINS BETACATENIN, APC, TCF-4 AND SURVIVIN IN GASTRIC ADENOCARCINOMA: CLINICAL AND PATHOLOGICAL IMPLICATION.

Science.gov (United States)

Lins, Rodrigo Rego; Oshima, Celina Tizuko Fujiyama; Oliveira, Levindo Alves de; Silva, Marcelo Souza; Mader, Ana Maria Amaral Antonio; Waisberg, Jaques

2016-01-01

Gastric cancer is the fifth most frequent cancer and the third most common cause of cancer-related deaths worldwide.It has been reported that Wnt/ betacatenin pathway is activated in 30-50% of these tumors. However,the deregulation of this pathway has not been fully elucidated. To determine the expression of E-cadherin, betacatenin, APC, TCF-4 and survivin proteins in gastric adenocarcinoma tissues and correlate with clinical and pathological parameters. Seventy-one patients with gastric adenocarcinoma undergoing gastrectomy were enrolled. The expression of E-cadherin, betacatenin, APC, TCF-4 and survivin proteins was detected by immunohistochemistryand related to the clinical and pathological parameters. The expression rates of E-cadherin in the membrane was 3%; betacatenin in the cytoplasm and nucleus were 23,4% and 3,1% respectively; APC in the cytoplasm was 94,6%; TCF-4 in the nucleus was 19,4%; and survivin in the nucleus 93,9%. The expression rate of E-cadherin was correlated with older patients (p=0,007), while betacatenin with tumors citoplasma e 3,1% no núcleo; APC em 94,6% no citoplasma; TCF-4 em19,4% no núcleo; e survivina em 93,9% no núcleo. Houve relação entre expressão da proteína E-caderina com a idade mais avançada (p=0,007); betacatenina com tumores <5 cm de diâmetro (p=0,041);APC com tumores proximais (p=0,047); e TCF-4 com tipo difuso da classificação de Lauren (p=0,017) e com o grau de penetração tumoral (p=0,002). A via Wnt/betacatenina não está envolvida na carcinogênese gástrica. Porém, a frequência elevada de survivina permite sugerir que outras vias sinalizadoras devam estar envolvidas na transformação do tecido gástrico.

Nurse- vs nomogram-directed glucose control in a cardiovascular intensive care unit.

Science.gov (United States)

Chant, Clarence; Mustard, Mary; Thorpe, Kevin E; Friedrich, Jan O

2012-07-01

Paper-based nomograms are reasonably effective for achieving glycemic control but have low adherence and are less adaptive than nurses' judgment. To compare efficacy (glucose control) and safety (hypoglycemia) achieved by use of a paper nomogram versus nurses' judgment. Prospective, randomized, open-label, crossover trial in an intensive care unit in postoperative patients with glucose concentrations greater than 8 mmol/L. Consenting nurses with at least 1 year of experience were randomized to use either their judgment or a validated paper-based nomogram for glucose control. After completion of 2 study shifts, the nurses used the alternative method for the next 2 study shifts. Glucose target level and safety and efficacy boundaries were the same for both methods. The primary end point was area under glucose time curve per hour. Thirty-four nurses contributed 95 shifts of data (44 nomogram-directed, 51 nurse-directed). Adherence to the nomogram was higher in the nomogram group than hypothetical adherence in the nurse-directed group for correct adjustments in insulin infusion (70% vs 37%; P unit where nurses generally accepted the need for tight glucose control, nurse-directed control was as effective and as safe as nomogram-based control.

Control range: a controllability-based index for node significance in directed networks

International Nuclear Information System (INIS)

Wang, Bingbo; Gao, Lin; Gao, Yong

2012-01-01

While a large number of methods for module detection have been developed for undirected networks, it is difficult to adapt them to handle directed networks due to the lack of consensus criteria for measuring the node significance in a directed network. In this paper, we propose a novel structural index, the control range, motivated by recent studies on the structural controllability of large-scale directed networks. The control range of a node quantifies the size of the subnetwork that the node can effectively control. A related index, called the control range similarity, is also introduced to measure the structural similarity between two nodes. When applying the index of control range to several real-world and synthetic directed networks, it is observed that the control range of the nodes is mainly influenced by the network's degree distribution and that nodes with a low degree may have a high control range. We use the index of control range similarity to detect and analyze functional modules in glossary networks and the enzyme-centric network of homo sapiens. Our results, as compared with other approaches to module detection such as modularity optimization algorithm, dynamic algorithm and clique percolation method, indicate that the proposed indices are effective and practical in depicting structural and modular characteristics of sparse directed networks

Quantifying direct effects of social determinants of health on glycemic control in adults with type 2 diabetes.

Science.gov (United States)

Walker, Rebekah J; Gebregziabher, Mulugeta; Martin-Harris, Bonnie; Egede, Leonard E

2015-02-01

The aim of this study was to investigate if self-care is the pathway through which social determinants of health impact diabetes outcomes by analyzing the direct and indirect effects of socioeconomic and psychosocial factors on self-care and glycemic control. Six hundred fifteen adults were recruited from two primary care clinics in the southeastern United States. A series of confirmatory factor analyses identified the latent factors underlying social status, psychosocial determinants (psychological distress, self-efficacy, and social support), and self-care (diet, exercise, foot care, glucose testing, and medication adherence). Structured equation modeling investigated the relationship among social determinants, self-care and glycemic control. Latent variables were created for diabetes self-care, psychological distress, self-efficacy, social support, and social status. The final model [χ(2)(275)=450.07, Psocial support (r=0.14, P=0.01), and higher self-efficacy (r=0.47, Psocial support (r=0.10, P=0.02), and higher self-efficacy (r=-0.37, Psocial determinants of health variables were included in the model, self-care was no longer significantly associated with glycemic control (r=0.01, P=0.83). This study suggests a direct relationship between psychosocial determinants of health and glycemic control. Although associated with self-care, the relationship between social determinants of health and glycemic control is not mediated by self-care. Development of interventions should take psychosocial factors into account as independent influences on diabetes outcomes, rather than as indirect influences via self-care behavior.

Cell density and N-cadherin interactions regulate cell proliferation in the sensory epithelia of the inner ear.

Science.gov (United States)

Warchol, Mark E

2002-04-01

Sensory hair cells in the inner ears of nonmammalian vertebrates can regenerate after injury. In many species, replacement hair cells are produced by the proliferation of epithelial supporting cells. Thus, the ability of supporting cells to undergo renewed proliferation is a key determinant of regenerative ability. The present study used cultures of isolated inner ear sensory epithelia to identify cellular signals that regulate supporting cell proliferation. Small pieces of sensory epithelia from the chicken utricle were cultured in glass microwells. Under those conditions, cell proliferation was inversely related to local cell density. The signaling molecules N-cadherin, beta-catenin, and focal adhesion kinase were immunolocalized in the cultured epithelial cells, and high levels of phosphotyrosine immunoreactivity were present at cell-cell junctions and focal contacts of proliferating cells. Binding of microbeads coated with a function-blocking antibody to N-cadherin inhibited ongoing proliferation. The growth of epithelial cells was also affected by the density of extracellular matrix molecules. The results suggest that cell density, cell-cell contact, and the composition of the extracellular matrix may be critical influences on the regulation of sensory regeneration in the inner ear.

Rac1 controls Schwann cell myelination through cAMP and NF2/merlin

Science.gov (United States)

Guo, Li; Moon, Chandra; Niehaus, Karen; Zheng, Yi; Ratner, Nancy

2013-01-01

During peripheral nervous system development, Schwann cells (SCs) surrounding single large axons differentiate into myelinating SCs. Previous studies implicate RhoGTPases in SC myelination, but the mechanisms involved in RhoGTPase regulation of SC myelination are unknown. Here, we show that SC myelination is arrested in Rac1 conditional knockout (Rac1-CKO) mice. Rac1 knockout abrogated phosphorylation of the effector p21-activated kinase (PAK) and decreased NF2/merlin phosphorylation. Mutation of NF2/merlin rescued the myelin deficit in Rac1-CKO mice in vivo, and the shortened processes in cultured Rac1-CKO SCs in vitro. Mechanistically, cyclic adenosine monophosphate (cAMP) levels and E-cadherin expression were decreased in the absence of Rac1, and both were restored by mutation of NF2/merlin. Reduced cAMP is a cause of the myelin deficiency in Rac1-CKO mice, as elevation of cAMP by rolipram in Rac1-CKO mice in vivo allowed myelin formation. Thus NF2/merlin and cAMP function downstream of Rac1 signaling in SC myelination, and cAMP levels control Rac1-regulated SC myelination. PMID:23197717

Expression of human beta-defensins-1-4 in thyroid cancer cells and new insight on biologic activity of hBD-2 in vitro.

Science.gov (United States)

Zhuravel, O V; Gerashchenko, O L; Khetsuriani, M R; Soldatkina, M A; Pogrebnoy, P V

2014-09-01

The study was aimed on analysis of human beta-defensin-1-4 (hBDs) mRNA expression in cultured thyroid cancer cells and evaluation of effects of recombinant hBD-2 (rec-hBD-2) on growth patterns, migration properties and expression of E-cadherin and vimentin in these cells. The study was performed on cultured follicular thyroid cancer WRO cells, papillary thyroid cancer TPC1 cells, and anaplastic thyroid cancer KTC-2 cells. For analysis of hBD-1-4 mRNA expression in thyroid cancer cells, semiquantitative RT-PCR was used. Effects of rec-hBD-2 on cell proliferation, viability, and migration were analyzed using direct cell counting, MTT test, and scratch assay respectively. Expression of vimentin and E-cadherin was evaluated by quantitative PCR (qPCR). By the data of RT-PCR, all three studied thyroid cancer cell lines express hBD-1 and -4 mRNA, but not hBD-2 mRNA, while hBD-3 expression was detected in WRO and KTC-2 cells. The treatment of TPC-1, WRO, and KTC-2 cells with 100-1000 nM rec-hBD-2 resulted in significant concentration-dependent suppression of cell proliferation, viability, and migratory property. By the data of qPCR, significant up-regulation of vimentin expression was registered in KTC-2 and WRO cells treated with 500 nM rec-hBD-2. Significant down-regulation of E-cadherin expression (p cells treated with the defensin. Also, it has been shown that TPC-1 cells treated with 500 nM rec-hBD-2 acquired more elongated morphology. The data demonstrate that hBD-2 in concentrations higher than 100 nM exerts significant concentration-dependent suppression of thyroid cancer cell growth and migration, and affects vimentin and E-cadherin expression dependent on histologic type of thyroid cancer cells.

Directional control-response compatibility of joystick steered shuttle cars.

Science.gov (United States)

Burgess-Limerick, Robin; Zupanc, Christine M; Wallis, Guy

2012-01-01

Shuttle cars are an unusual class of vehicle operated in underground coal mines, sometimes in close proximity to pedestrians and steering errors may have very serious consequences. A directional control-response incompatibility has previously been described in shuttle cars which are controlled using a steering wheel oriented perpendicular to the direction of travel. Some other shuttle car operators are seated perpendicular to the direction of travel and steer the car via a seat mounted joystick. A virtual simulation was utilised to determine whether the steering arrangement in these vehicles maintains directional control-response compatibility. Twenty-four participants were randomly assigned to either a condition corresponding to this design (consistent direction), or a condition in which the directional steering response was reversed while driving in-bye (visual field compatible). Significantly less accurate steering performance was exhibited by the consistent direction group during the in-bye trials only. Shuttle cars which provide the joystick steering mechanism described here require operators to accommodate alternating compatible and incompatible directional control-response relationships with each change of car direction. A virtual simulation of an underground coal shuttle car demonstrates that the design incorporates a directional control-response incompatibility when driving the vehicle in one direction. This design increases the probability of operator error, with potential adverse safety and productivity consequences.

VE-Cadherin-Mediated Epigenetic Regulation of Endothelial Gene Expression.

Science.gov (United States)

Morini, Marco F; Giampietro, Costanza; Corada, Monica; Pisati, Federica; Lavarone, Elisa; Cunha, Sara I; Conze, Lei L; O'Reilly, Nicola; Joshi, Dhira; Kjaer, Svend; George, Roger; Nye, Emma; Ma, Anqi; Jin, Jian; Mitter, Richard; Lupia, Michela; Cavallaro, Ugo; Pasini, Diego; Calado, Dinis P; Dejana, Elisabetta; Taddei, Andrea

2018-01-19

The mechanistic foundation of vascular maturation is still largely unknown. Several human pathologies are characterized by deregulated angiogenesis and unstable blood vessels. Solid tumors, for instance, get their nourishment from newly formed structurally abnormal vessels which present wide and irregular interendothelial junctions. Expression and clustering of the main endothelial-specific adherens junction protein, VEC (vascular endothelial cadherin), upregulate genes with key roles in endothelial differentiation and stability. We aim at understanding the molecular mechanisms through which VEC triggers the expression of a set of genes involved in endothelial differentiation and vascular stabilization. We compared a VEC-null cell line with the same line reconstituted with VEC wild-type cDNA. VEC expression and clustering upregulated endothelial-specific genes with key roles in vascular stabilization including claudin-5 , vascular endothelial-protein tyrosine phosphatase ( VE-PTP ), and von Willebrand factor ( vWf ). Mechanistically, VEC exerts this effect by inhibiting polycomb protein activity on the specific gene promoters. This is achieved by preventing nuclear translocation of FoxO1 (Forkhead box protein O1) and β-catenin, which contribute to PRC2 (polycomb repressive complex-2) binding to promoter regions of claudin-5 , VE-PTP , and vWf . VEC/β-catenin complex also sequesters a core subunit of PRC2 (Ezh2 [enhancer of zeste homolog 2]) at the cell membrane, preventing its nuclear translocation. Inhibition of Ezh2/VEC association increases Ezh2 recruitment to claudin-5 , VE-PTP , and vWf promoters, causing gene downregulation. RNA sequencing comparison of VEC-null and VEC-positive cells suggested a more general role of VEC in activating endothelial genes and triggering a vascular stability-related gene expression program. In pathological angiogenesis of human ovarian carcinomas, reduced VEC expression paralleled decreased levels of claudin-5 and VE-PTP. These

Topology Control in Aerial Multi-Beam Directional Networks

Science.gov (United States)

2017-04-24

Topology Control in Aerial Multi-Beam Directional Networks Brian Proulx, Nathaniel M. Jones, Jennifer Madiedo, Greg Kuperman {brian.proulx, njones...significant interference. Topology control (i.e., selecting a subset of neighbors to communicate with) is vital to reduce the interference. Good topology ...underlying challenges to topology control in multi-beam direction networks. Two topology control algorithms are developed: a centralized algorithm

A Regulatory Network Involving β‐Catenin, e‐Cadherin, PI3k/Akt, and Slug Balances Self‐Renewal and Differentiation of Human Pluripotent Stem Cells In Response to Wnt Signaling

Science.gov (United States)

Huang, Tyng‐Shyan; Li, Li; Moalim‐Nour, Lilian; Jia, Deyong; Bai, Jian; Yao, Zemin; Bennett, Steffany A. L.; Figeys, Daniel

2015-01-01

Abstract The mechanisms underlying disparate roles of the canonical Wnt signaling pathway in maintaining self‐renewal or inducing differentiation and lineage specification in embryonic stem cells (ESCs) are not clear. In this study, we provide the first demonstration that self‐renewal versus differentiation of human ESCs (hESCs) in response to Wnt signaling is predominantly determined by a two‐layer regulatory circuit involving β‐catenin, E‐cadherin, PI3K/Akt, and Slug in a time‐dependent manner. Short‐term upregulation of β‐catenin does not lead to the activation of T‐cell factor (TCF)‐eGFP Wnt reporter in hESCs. Instead, it enhances E‐cadherin expression on the cell membrane, thereby enhancing hESC self‐renewal through E‐cadherin‐associated PI3K/Akt signaling. Conversely, long‐term Wnt activation or loss of E‐cadherin intracellular β‐catenin binding domain induces TCF‐eGFP activity and promotes hESC differentiation through β‐catenin‐induced upregulation of Slug. Enhanced expression of Slug leads to a further reduction of E‐cadherin that serves as a β‐catenin “sink” sequestering free cytoplasmic β‐catenin. The formation of such a framework reinforces hESCs to switch from a state of temporal self‐renewal associated with short‐term Wnt/β‐catenin activation to definitive differentiation. Stem Cells 2015;33:1419–1433 PMID:25538040

N-cadherin{sup +} HSCs in fetal liver exhibit higher long-term bone marrow reconstitution activity than N-cadherin{sup -} HSCs

Energy Technology Data Exchange (ETDEWEB)

Toyama, Hirofumi; Arai, Fumio; Hosokawa, Kentaro; Ikushima, Yoshiko Matsumoto [Department of Cell Differentiation, The Sakaguchi Laboratory of Developmental Biology, School of Medicine, Keio University, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Suda, Toshio, E-mail: sudato@z3.keio.jp [Department of Cell Differentiation, The Sakaguchi Laboratory of Developmental Biology, School of Medicine, Keio University, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan)

2012-11-23

Highlights: Black-Right-Pointing-Pointer High N-cad expression was detected in E12.5 mouse FL LT-HSCs (EPCR{sup +} LSK cells). Black-Right-Pointing-Pointer Immunohistochemically, N-cad{sup +} HSCs co-localized with sinusoidal ECs (Lyve-1{sup +} cells) in E12.5 FL, but these gradually detached in E15.5 and E18.5 FL. Black-Right-Pointing-Pointer N-cad{sup +} LSK cells in E12.5 FL exhibited higher LTR activity versus N-cad{sup -} LSK cells, which decreased in E15.5 and E18.5. Black-Right-Pointing-Pointer N-cad expression may confer high LTR activity to HSCs by facilitating interactions with the perisinusoidal niche in FL. -- Abstract: Adult hematopoietic stem cells (HSCs) are maintained in a microenvironment known as the stem cell niche. The regulation of HSCs in fetal liver (FL) and their niche, however, remains to be elucidated. In this study, we investigated the role of N-cadherin (N-cad) in the maintenance of HSCs during FL hematopoiesis. By using anti-N-cad antibodies (Abs) produced by our laboratory, we detected high N-cad expression in embryonic day 12.5 (E12.5) mouse FL HSCs, but not in E15.5 and E18.5 FL. Immunofluorescence staining revealed that N-cad{sup +}c-Kit{sup +} and N-cad{sup +} endothelial protein C receptor (EPCR){sup +} HSCs co-localized with Lyve-1{sup +} sinusoidal endothelial cells (ECs) in E12.5 FL and that some of these cells also expressed N-cad. However, N-cad{sup +} HSCs were also observed to detach from the perisinusoidal niche at E15.5 and E18.5, concomitant with a down-regulation of N-cad and an up-regulation of E-cadherin (E-cad) in hepatic cells. Moreover, EPCR{sup +} long-term (LT)-HSCs were enriched in the N-cad{sup +}Lin{sup -}Sca-1{sup +}c-Kit{sup +} (LSK) fraction in E12.5 FL, but not in E15.5 or E18.5 FL. In a long-term reconstitution (LTR) activity assay, higher engraftment associated with N-cad{sup +} LSK cells versus N-cad{sup -} LSK cells in E12.5 FL when transplanted into lethally irradiated recipient mice. However, the

Rapid paracellular transmigration of Campylobacter jejuni across polarized epithelial cells without affecting TER: role of proteolytic-active HtrA cleaving E-cadherin but not fibronectin

LENUS (Irish Health Repository)

Boehm, Manja

2012-04-25

AbstractBackgroundCampylobacter jejuni is one of the most important bacterial pathogens causing food-borne illness worldwide. Crossing the intestinal epithelial barrier and host cell entry by C. jejuni is considered the primary reason of damage to the intestinal tissue, but the molecular mechanisms as well as major bacterial and host cell factors involved in this process are still widely unclear.ResultsIn the present study, we characterized the serine protease HtrA (high-temperature requirement A) of C. jejuni as a secreted virulence factor with important proteolytic functions. Infection studies and in vitro cleavage assays showed that C. jejuni’s HtrA triggers shedding of the extracellular E-cadherin NTF domain (90 kDa) of non-polarised INT-407 and polarized MKN-28 epithelial cells, but fibronectin was not cleaved as seen for H. pylori’s HtrA. Deletion of the htrA gene in C. jejuni or expression of a protease-deficient S197A point mutant did not lead to loss of flagella or reduced bacterial motility, but led to severe defects in E-cadherin cleavage and transmigration of the bacteria across polarized MKN-28 cell layers. Unlike other highly invasive pathogens, transmigration across polarized cells by wild-type C. jejuni is highly efficient and is achieved within a few minutes of infection. Interestingly, E-cadherin cleavage by C. jejuni occurs in a limited fashion and transmigration required the intact flagella as well as HtrA protease activity, but does not reduce transepithelial electrical resistance (TER) as seen with Salmonella, Shigella, Listeria or Neisseria.ConclusionThese results suggest that HtrA-mediated E-cadherin cleavage is involved in rapid crossing of the epithelial barrier by C. jejuni via a very specific mechanism using the paracellular route to reach basolateral surfaces, but does not cleave the fibronectin receptor which is necessary for cell entry.

Rapid paracellular transmigration of Campylobacter jejuni across polarized epithelial cells without affecting TER: role of proteolytic-active HtrA cleaving E-cadherin but not fibronectin.

Science.gov (United States)

Boehm, Manja; Hoy, Benjamin; Rohde, Manfred; Tegtmeyer, Nicole; Bæk, Kristoffer T; Oyarzabal, Omar A; Brøndsted, Lone; Wessler, Silja; Backert, Steffen

2012-04-25

Campylobacter jejuni is one of the most important bacterial pathogens causing food-borne illness worldwide. Crossing the intestinal epithelial barrier and host cell entry by C. jejuni is considered the primary reason of damage to the intestinal tissue, but the molecular mechanisms as well as major bacterial and host cell factors involved in this process are still widely unclear. In the present study, we characterized the serine protease HtrA (high-temperature requirement A) of C. jejuni as a secreted virulence factor with important proteolytic functions. Infection studies and in vitro cleavage assays showed that C. jejuni's HtrA triggers shedding of the extracellular E-cadherin NTF domain (90 kDa) of non-polarised INT-407 and polarized MKN-28 epithelial cells, but fibronectin was not cleaved as seen for H. pylori's HtrA. Deletion of the htrA gene in C. jejuni or expression of a protease-deficient S197A point mutant did not lead to loss of flagella or reduced bacterial motility, but led to severe defects in E-cadherin cleavage and transmigration of the bacteria across polarized MKN-28 cell layers. Unlike other highly invasive pathogens, transmigration across polarized cells by wild-type C. jejuni is highly efficient and is achieved within a few minutes of infection. Interestingly, E-cadherin cleavage by C. jejuni occurs in a limited fashion and transmigration required the intact flagella as well as HtrA protease activity, but does not reduce transepithelial electrical resistance (TER) as seen with Salmonella, Shigella, Listeria or Neisseria. These results suggest that HtrA-mediated E-cadherin cleavage is involved in rapid crossing of the epithelial barrier by C. jejuni via a very specific mechanism using the paracellular route to reach basolateral surfaces, but does not cleave the fibronectin receptor which is necessary for cell entry.

Loss of lateral prefrontal cortex control in food-directed attention and goal-directed food choice in obesity.

Science.gov (United States)

Janssen, Lieneke K; Duif, Iris; van Loon, Ilke; Wegman, Joost; de Vries, Jeanne H M; Cools, Roshan; Aarts, Esther

2017-02-01

Loss of lateral prefrontal cortex (lPFC)-mediated attentional control may explain the automatic tendency to eat in the face of food. Here, we investigate the neurocognitive mechanism underlying attentional bias to food words and its association with obesity using a food Stroop task. We tested 76 healthy human subjects with a wide body mass index (BMI) range (19-35kg/m 2 ) using fMRI. As a measure of obesity we calculated individual obesity scores based on BMI, waist circumference and waist-to-hip ratio using principal component analyses. To investigate the automatic tendency to overeat directly, the same subjects performed a separate behavioral outcome devaluation task measuring the degree of goal-directed versus automatic food choices. We observed that increased obesity scores were associated with diminished lPFC responses during food attentional bias. This was accompanied by decreased goal-directed control of food choices following outcome devaluation. Together these findings suggest that deficient control of both food-directed attention and choice may contribute to obesity, particularly given our obesogenic environment with food cues everywhere, and the choice to ignore or indulge despite satiety. Copyright © 2016 Elsevier Inc. All rights reserved.

Decentralized adaptive control of interconnected nonlinear systems with unknown control directions.

Science.gov (United States)

Huang, Jiangshuai; Wang, Qing-Guo

2018-03-01

In this paper, we propose a decentralized adaptive control scheme for a class of interconnected strict-feedback nonlinear systems without a priori knowledge of subsystems' control directions. To address this problem, a novel Nussbaum-type function is proposed and a key theorem is drawn which involves quantifying the interconnections of multiple Nussbaum-type functions of the subsystems with different control directions in a single inequality. Global stability of the closed-loop system and asymptotic stabilization of subsystems' output are proved and a simulation example is given to illustrate the effectiveness of the proposed control scheme. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

The soluble extracellular domain of E-cadherin interferes with EPEC adherence via interaction with the Tir:intimin complex.

Science.gov (United States)

Login, Frédéric H; Jensen, Helene H; Pedersen, Gitte A; Amieva, Manuel R; Nejsum, Lene N

2018-06-19

Enteropathogenic Escherichia coli (EPEC) causes watery diarrhea when colonizing the surface of enterocytes. The translocated intimin receptor (Tir):intimin receptor complex facilitates tight adherence to epithelial cells and formation of actin pedestals beneath EPEC. We found that the host cell adherens junction protein E-cadherin (Ecad) was recruited to EPEC microcolonies. Live-cell and confocal imaging revealed that Ecad recruitment depends on, and occurs after, formation of the Tir:intimin complex. Combinatorial binding experiments using wild-type EPEC, isogenic mutants lacking Tir or intimin, and E. coli expressing intimin showed that the extracellular domain of Ecad binds the bacterial surface in a Tir:intimin-dependent manner. Finally, addition of the soluble extracellular domain of Ecad to the infection medium or depletion of Ecad extracellular domain from the cell surface reduced EPEC adhesion to host cells. Thus, the soluble extracellular domain of Ecad may be used in the design of intervention strategies targeting EPEC adherence to host cells.-Login, F. H., Jensen, H. H., Pedersen, G. A., Amieva, M. R., Nejsum, L. N. The soluble extracellular domain of E-cadherin interferes with EPEC adherence via interaction with the Tir:intimin complex.

Estudo da expressão da proteína caderina-E correlacionada com o grau de diferenciação celular e o estadiamento TNM do adenocarcinoma colorretal Relationship study between the cadherin-E protein cell diferentiation and TNM staging

Directory of Open Access Journals (Sweden)

Marcos Vinicius Araujo Denadai

2006-09-01

Full Text Available OBJETIVO: Avaliar a relação de uma proteína que participa do mecanismo de adesão celular com o grau de diferenciação celular e o estadiamento TNM I e IV no CCR. MÉTODOS: Foram estudados 100 pacientes (54 homens e 46 mulheres tratados por CCR, estádio I - 44 pacientes, estádio IV - 56 pacientes. Os cortes histológicos do tecido tumoral foram examinados por técnica de imunohistoquímica em relação à expressão da proteína caderina-E. Os cortes histológicos foram classificados como positivos ou negativos pelo método semiquantitativo. RESULTADOS: Para o TNM, expressão da caderina-E estádio I: positiva em 72,7 % e negativa em 35,7% ; estádio IV: positiva em 64,3% e negativa em 35,7%. Em relação ao grau de diferenciação celular, expressão da caderina-E; G I: positiva em 70% e negativa em 30%; G II: positiva em 68.4% e 31,6% negativa; G III: 63.6% positiva e 36,4 % negativa.. Não houve diferença significativa entre os grupos. CONCLUSÃO: Os resultados dessa pesquisa permitem concluir que não há relação da expressão da proteína caderina-E com o estadiamento TNM (I e IV e o grau de diferenciação celular no CCR.OBJECTIVE: To evaluate the relationship of a protein that take part in the same mechanism of cell adhesion with the cell differentiation degree and TNM staging I and IV in CRA. METHODS: One-hundred patients (54 men and 46 women, who have received treatment for CRA, stage I - 44 patients and stage IV - 56 patients, have been studied. Histological cuts of tumor tissue were examined by the immunohistochemical technique as to the expression of E-cadherin proteins. Such histological cuts were classified as positive or negative through the semi-quantitative method. RESULTS: For TNM, the E-cadherin expression for stage I: positive in 72.7% and negative in 35.7%; stage IV: positive in 64.3% and negative in 35.7%. Regarding the cell differentiation degree, the expression of E-cadherin, GI: positive in 70% and negative in

Role of the adiponectin binding protein, T-cadherin (Cdh13, in allergic airways responses in mice.

Directory of Open Access Journals (Sweden)

Alison S Williams

Full Text Available Adiponectin is an adipose derived hormone that declines in obesity. We have previously shown that exogenous administration of adiponectin reduces allergic airways responses in mice. T-cadherin (T-cad; Cdh13 is a binding protein for the high molecular weight isoforms of adiponectin. To determine whether the beneficial effects of adiponectin on allergic airways responses require T-cad, we sensitized wildtype (WT, T-cadherin deficient (T-cad(-/- and adiponectin and T-cad bideficient mice to ovalbumin (OVA and challenged the mice with aerosolized OVA or PBS. Compared to WT, T-cad(-/- mice were protected against OVA-induced airway hyperresponsiveness, increases in BAL inflammatory cells, and induction of IL-13, IL-17, and eotaxin expression. Histological analysis of the lungs of OVA-challenged T-cad(-/- versus WT mice indicated reduced inflammation around the airways, and reduced mucous cell hyperplasia. Combined adiponectin and T-cad deficiency reversed the effects of T-cad deficiency alone, indicating that the observed effects of T-cad deficiency require adiponectin. Compared to WT, serum adiponectin was markedly increased in T-cad(-/- mice, likely because adiponectin that is normally sequestered by endothelial T-cad remains free in the circulation. In conclusion, T-cad does not mediate the protective effects of adiponectin. Instead, mice lacking T-cad have reduced allergic airways disease, likely because elevated serum adiponectin levels act on other adiponectin signaling pathways.

Development of compact toroids injector for direct plasma controls

International Nuclear Information System (INIS)

Azuma, K.; Oda, Y.; Onozuka, M.; Uyama, T.; Nagata, M.; Fukumoto, N.

1995-01-01

The application of the compact toroids injector for direct plasma controls has been investigated. The compact toroids injection can fuel particles directly into the core of the plasma and modify the plasma profiles at the desired locations. The acceleration tests of the compact toroids have been conducted at Himeji Institute of Technology. The tests showed that the hydrogen compact toroid was accelerated up to 80km/s and the plasma density of the compact toroid was compressed to 1.2 x 10 21 m -3 . (orig.)

Co-culture of neural crest stem cells (NCSC and insulin producing beta-TC6 cells results in cadherin junctions and protection against cytokine-induced beta-cell death.

Directory of Open Access Journals (Sweden)

Anongnad Ngamjariyawat

Full Text Available PURPOSE: Transplantation of pancreatic islets to Type 1 diabetes patients is hampered by inflammatory reactions at the transplantation site leading to dysfunction and death of insulin producing beta-cells. Recently we have shown that co-transplantation of neural crest stem cells (NCSCs together with the islet cells improves transplantation outcome. The aim of the present investigation was to describe in vitro interactions between NCSCs and insulin producing beta-TC6 cells that may mediate protection against cytokine-induced beta-cell death. PROCEDURES: Beta-TC6 and NCSC cells were cultured either alone or together, and either with or without cell culture inserts. The cultures were then exposed to the pro-inflammatory cytokines IL-1β and IFN-γ for 48 hours followed by analysis of cell death rates (flow cytometry, nitrite production (Griess reagent, protein localization (immunofluorescence and protein phosphorylation (flow cytometry. RESULTS: We observed that beta-TC6 cells co-cultured with NCSCs were protected against cytokine-induced cell death, but not when separated by cell culture inserts. This occurred in parallel with (i augmented production of nitrite from beta-TC6 cells, indicating that increased cell survival allows a sustained production of nitric oxide; (ii NCSC-derived laminin production; (iii decreased phospho-FAK staining in beta-TC6 cell focal adhesions, and (iv decreased beta-TC6 cell phosphorylation of ERK(T202/Y204, FAK(Y397 and FAK(Y576. Furthermore, co-culture also resulted in cadherin and beta-catenin accumulations at the NCSC/beta-TC6 cell junctions. Finally, the gap junction inhibitor carbenoxolone did not affect cytokine-induced beta-cell death during co-culture with NCSCs. CONCLUSION: In summary, direct contacts, but not soluble factors, promote improved beta-TC6 viability when co-cultured with NCSCs. We hypothesize that cadherin junctions between NCSC and beta-TC6 cells promote powerful signals that maintain beta

Ca2+-dependent localization of integrin-linked kinase to cell junctions in differentiating keratinocytes.

Science.gov (United States)

Vespa, Alisa; Darmon, Alison J; Turner, Christopher E; D'Souza, Sudhir J A; Dagnino, Lina

2003-03-28

Integrin complexes are necessary for proper proliferation and differentiation of epidermal keratinocytes. Differentiation of these cells is accompanied by down-regulation of integrins and focal adhesions as well as formation of intercellular adherens junctions through E-cadherin homodimerization. A central component of integrin adhesion complexes is integrin-linked kinase (ILK), which can induce loss of E-cadherin expression and epithelial-mesenchymal transformation when ectopically expressed in intestinal and mammary epithelia. In cultured primary mouse keratinocytes, we find that ILK protein levels are independent of integrin expression and signaling, since they remain constant during Ca(2+)-induced differentiation. In contrast, keratinocyte differentiation is accompanied by marked reduction in kinase activity in ILK immunoprecipitates and altered ILK subcellular distribution. Specifically, ILK distributes in close apposition to actin fibers along intercellular junctions in differentiated but not in undifferentiated keratinocytes. ILK localization to cell-cell borders occurs independently of integrin signaling and requires Ca(2+) as well as an intact actin cytoskeleton. Further, and in contrast to what is observed in other epithelial cells, ILK overexpression in differentiated keratinocytes does not promote E-cadherin down-regulation and epithelial-mesenchymal transition. Thus, novel tissue-specific mechanisms control the formation of ILK complexes associated with cell-cell junctions in differentiating murine epidermal keratinocytes.

Development of compact toroids injector for direct plasma controls

Energy Technology Data Exchange (ETDEWEB)

Azuma, K. [Mitsubishi Heavy Industries Ltd., Takasago (Japan); Oda, Y. [Mitsubishi Heavy Industries Ltd., Takasago (Japan); Onozuka, M. [Mitsubishi Heavy Industries Ltd., Takasago (Japan); Uyama, T. [Himeji Inst. of Tech. (Japan); Nagata, M. [Himeji Inst. of Tech. (Japan); Fukumoto, N. [Himeji Inst. of Tech. (Japan)

1995-12-31

The application of the compact toroids injector for direct plasma controls has been investigated. The compact toroids injection can fuel particles directly into the core of the plasma and modify the plasma profiles at the desired locations. The acceleration tests of the compact toroids have been conducted at Himeji Institute of Technology. The tests showed that the hydrogen compact toroid was accelerated up to 80km/s and the plasma density of the compact toroid was compressed to 1.2 x 10{sup 21}m{sup -3}. (orig.).

Existe alteração no mecanismo de adesão celular mediado pela E-caderina nas neoplasias cervicais de pacientes soropositivas para o HIV? Is there any change in the cell adhesion method mediated by e-cadherin in cervical neoplasia of HIV-infected patients?

Directory of Open Access Journals (Sweden)

Juliana Barroso Zimmermmann

2010-06-01

Full Text Available OBJETIVOS: avaliar a expressão da E-caderina em lesões do colo uterino em pacientes portadoras da infecção pelo vírus HIV. MÉTODOS: foi realizado um estudo com 77 pacientes apresentando o HPV cervical, sendo 40 soropositivas e 37 soronegativas para o HIV, todas submetidas à colposcopia e biópsia de colo uterino. O material obtido foi encaminhado para histopatologia e imunoistoquímica. Foram realizados cortes e montagem em lâminas silanizadas, e o observador foi blindado para a sorologia da paciente. Foram utilizados os anticorpos E-caderina, marca DAKO, clone NHC-38, com diluição de 1:400, e o sistema de polímeros Novolink (Novocastra. A expressão de E-caderina foi avaliada na membrana da célula epitelial, através da extensão da área corada. Utilizou-se o teste do χ2 com correção de Yates ou o teste de Fisher, para comparação de proporções na análise univariada. Foram incluídas no modelo de regressão logística todas as variáveis com valor pPURPOSE: to evaluate the expression of E-cadherin in cervical lesions of patients suffering from HIV infection. METHODS: we conducted a study with 77 patients with cervical HPV infection, 40 of them were HIV seropositive and 37 HIV seronegative who underwent colposcopy and a biopsy of the cervix. The material obtained by biopsy of the cervix was sent for histopathologic and immunohistochemical study. Sections were obtained and mounted on silanized slides and examined by an observer who was blind to patient serology. E-cadherin antibody, clone NHC-38 diluted 1:400 (DAKO and the Novolink polymer system (Novocastra were used. The expression of E-cadherin was determined on the epithelial cell membrane based on the extent of the stained area. The χ2 test with Yates correction or the Fisher's Exact test was used for comparison of the proportion in univariate analysis. All the variables with p<0.25 were included in the logistic regression model, called initial model. The analyses were

The over expression of long non-coding RNA ANRIL promotes epithelial-mesenchymal transition by activating the ATM-E2F1 signaling pathway in pancreatic cancer: An in vivo and in vitro study.

Science.gov (United States)

Chen, Shi; Zhang, Jia-Qiang; Chen, Jiang-Zhi; Chen, Hui-Xing; Qiu, Fu-Nan; Yan, Mao-Lin; Chen, Yan-Ling; Peng, Cheng-Hong; Tian, Yi-Feng; Wang, Yao-Dong

2017-09-01

This study aims to investigate the roles of lncRNA ANRIL in epithelial-mesenchymal transition (EMT) by regulating the ATM-E2F1 signaling pathway in pancreatic cancer (PC). PC rat models were established and ANRIL overexpression and interference plasmids were transfected. The expression of ANRIL, EMT markers (E-cadherin, N-cadherin and Vimentin) and ATM-E2F1 signaling pathway-related proteins (ATM, E2F1, INK4A, INK4B and ARF) were detected. Small molecule drugs were applied to activate and inhibit the ATM-E2F1 signaling pathway. Transwell assay and the scratch test were adopted to detect cell invasion and migration abilities. ANRIL expression in the PC cells was higher than in normal pancreatic duct epithelial cells. In the PC rat models and PC cells, ANRIL interference promoted the expressions of INK4B, INK4A, ARF and E-cadherin, while reduced N-cadherin and Vimentin expression. Over-expressed ANRIL decreased the expression of INK4B, INK4A, ARF and E-cadherin, but raised N-cadherin and Vimentin expressions. By inhibiting the ATM-E2F1 signaling pathway in PC cells, E-cadherin expression increased but N-cadherin and Vimentin expressions decreased. After ANRIL was silenced or the ATM-E2F1 signaling pathway inhibited, PC cell migration and invasion abilities were decreased. In conclusion, over-expression of lncRNA ANRIL can promote EMT of PC cells by activating the ATM-E2F1 signaling pathway. Copyright © 2017 Elsevier B.V. All rights reserved.

MicroRNAs let-7b/i suppress human glioma cell invasion and migration by targeting IKBKE directly

Energy Technology Data Exchange (ETDEWEB)

Tian, Yuan; Hao, Shaobo [Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin 300052 (China); Laboratory of Neuro-Oncology, Tianjin Neurological Institute, Tianjin 300052 (China); Key Laboratory of Neurotrauma, Variation and Regeneration, Ministry of Education and Tianjin Municipal Government (China); Ye, Minhua [Department of Neurosurgery, Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi Province 330006 (China); Zhang, Anling [Laboratory of Neuro-Oncology, Tianjin Neurological Institute, Tianjin 300052 (China); Key Laboratory of Neurotrauma, Variation and Regeneration, Ministry of Education and Tianjin Municipal Government (China); Nan, Yang [Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin 300052 (China); Wang, Guangxiu; Jia, Zhifan [Laboratory of Neuro-Oncology, Tianjin Neurological Institute, Tianjin 300052 (China); Key Laboratory of Neurotrauma, Variation and Regeneration, Ministry of Education and Tianjin Municipal Government (China); Yu, Kai; Guo, Lianmei [Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin 300052 (China); Pu, Peiyu [Laboratory of Neuro-Oncology, Tianjin Neurological Institute, Tianjin 300052 (China); Key Laboratory of Neurotrauma, Variation and Regeneration, Ministry of Education and Tianjin Municipal Government (China); Huang, Qiang, E-mail: huangqiang209@163.com [Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin 300052 (China); Zhong, Yue, E-mail: zhongyue2457@sina.com [Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin 300052 (China)

2015-03-06

We demonstrated that IKBKE is overexpressed in human gliomas and that the downregulation of IKBKE markedly inhibits the proliferative and invasive abilities of glioma cells, which is consistent with the results reported by several different research groups. Therefore, IKBKE represents a promising therapeutic target for the treatment of glioma. In the present study, we verified that the microRNAs let-7b and let-7i target IKBKE through luciferase assays and found that let-7b/i mimics can knock down IKBKE and upregulate E-cadherin through western blot analysis. Moreover, the expression levels of let-7b/i were significantly lower in glioma cell lines than that in normal brain tissues, as determined by quantitative real-time PCR. Furthermore, let-7b/i inhibit the invasion and migration of glioma cells, as determined through wound healing and Transwell assays. The above-mentioned data suggest that let-7b/i inhibit the invasive ability of glioma cells by directly downregulating IKBKE and indirectly upregulating E-cadherin. - Highlights: • Let-7b and let-7i are downregulated in glioma cell lines. • IKBKE is a target gene of let-7b/i. • Let-7b/i inhibit the invasion and migration of glioma cells. • Let-7b/i upregulate E-cadherin by downregulating IKBKE.

MicroRNAs let-7b/i suppress human glioma cell invasion and migration by targeting IKBKE directly

International Nuclear Information System (INIS)

Tian, Yuan; Hao, Shaobo; Ye, Minhua; Zhang, Anling; Nan, Yang; Wang, Guangxiu; Jia, Zhifan; Yu, Kai; Guo, Lianmei; Pu, Peiyu; Huang, Qiang; Zhong, Yue

2015-01-01

We demonstrated that IKBKE is overexpressed in human gliomas and that the downregulation of IKBKE markedly inhibits the proliferative and invasive abilities of glioma cells, which is consistent with the results reported by several different research groups. Therefore, IKBKE represents a promising therapeutic target for the treatment of glioma. In the present study, we verified that the microRNAs let-7b and let-7i target IKBKE through luciferase assays and found that let-7b/i mimics can knock down IKBKE and upregulate E-cadherin through western blot analysis. Moreover, the expression levels of let-7b/i were significantly lower in glioma cell lines than that in normal brain tissues, as determined by quantitative real-time PCR. Furthermore, let-7b/i inhibit the invasion and migration of glioma cells, as determined through wound healing and Transwell assays. The above-mentioned data suggest that let-7b/i inhibit the invasive ability of glioma cells by directly downregulating IKBKE and indirectly upregulating E-cadherin. - Highlights: • Let-7b and let-7i are downregulated in glioma cell lines. • IKBKE is a target gene of let-7b/i. • Let-7b/i inhibit the invasion and migration of glioma cells. • Let-7b/i upregulate E-cadherin by downregulating IKBKE

Entry: direct control or regulation?

NARCIS (Netherlands)

Perotti, E.; Vorage, M.

2009-01-01

We model a setting in which citizens form coalitions to seek preferential entry to a given market. The lower entry the higher firm profits and political contributions, but the lower social welfare. Politicians choose to either control entry directly and be illegally bribed, or regulate entry using a

Reduced E-cadherin expression is associated with abdominal pain and symptom duration in a study of alternating and diarrhea predominant IBS.

LENUS (Irish Health Repository)

Wilcz-Villega, E

2013-11-29

Increased intestinal permeability and altered expression of tight junction (TJ) proteins may be implicated in the pathogenesis of irritable bowel syndrome (IBS). This study aimed to investigate the expression of adherens junction (AJ) protein E-cadherin and TJ proteins zonula occludens (ZO)-1 and claudin (CLD)-1 and associations with IBS symptoms.

A osteogenesis distraction device enabling control of vertical direction for syndromic craniosynostosis.

Science.gov (United States)

Kobayashi, Shinji; Fukawa, Toshihiko; Hirakawa, Takashi; Maegawa, Jiro

2014-02-01

We have developed a hybrid facial osteogenesis distraction system that combines the advantages of external and internal distraction devices to enable control of both the distraction distance and vector. However, when the advanced maxilla has excessive clockwise rotation and shifts more downward vertically than planned, it might be impossible to pull it up to correct it. We invented devices attached to external distraction systems that can control the vertical vector of distraction to resolve this problem. The purpose of this article is to describe the result of utilizing the distraction system for syndromic craniosynostosis. In addition to a previously reported hybrid facial distraction system, the devices for controlling the vertical direction of the advanced maxilla were attached to the external distraction device. The vertical direction of the advanced maxilla can be controlled by adjustment of the spindle units. This system was used for 2 patients with Crouzon and Apert syndrome. The system enabled control of the vertical distance, with no complications during the procedures. As a result, the maxilla could be advanced into the planned position including overcorrection without excessive clockwise rotation of distraction. Our system can alter the cases and bring them into the planned position, by controlling the vertical vector of distraction. We believe that this system might be effective in infants with syndromic craniosynostosis as it involves 2 osteotomies and horizontal and vertical direction of elongation can be controlled.

Direct adaptive control using feedforward neural networks

OpenAIRE

Cajueiro, Daniel Oliveira; Hemerly, Elder Moreira

2003-01-01

ABSTRACT: This paper proposes a new scheme for direct neural adaptive control that works efficiently employing only one neural network, used for simultaneously identifying and controlling the plant. The idea behind this structure of adaptive control is to compensate the control input obtained by a conventional feedback controller. The neural network training process is carried out by using two different techniques: backpropagation and extended Kalman filter algorithm. Additionally, the conver...

Mutation of CDH23, encoding a new member of the cadherin gene family, causes Usher syndrome type 1D.

Science.gov (United States)

Bolz, H; von Brederlow, B; Ramírez, A; Bryda, E C; Kutsche, K; Nothwang, H G; Seeliger, M; del C-Salcedó Cabrera, M; Vila, M C; Molina, O P; Gal, A; Kubisch, C

2001-01-01

Usher syndrome type I (USH1) is an autosomal recessive disorder characterized by congenital sensorineural hearing loss, vestibular dysfunction and visual impairment due to early onset retinitis pigmentosa (RP). So far, six loci (USH1A-USH1F) have been mapped, but only two USH1 genes have been identified: MYO7A for USH1B and the gene encoding harmonin for USH1C. We identified a Cuban pedigree linked to the locus for Usher syndrome type 1D (MIM 601067) within the q2 region of chromosome 10). Affected individuals present with congenital deafness and a highly variable degree of retinal degeneration. Using a positional candidate approach, we identified a new member of the cadherin gene superfamily, CDH23. It encodes a protein of 3,354 amino acids with a single transmembrane domain and 27 cadherin repeats. In the Cuban family, we detected two different mutations: a severe course of the retinal disease was observed in individuals homozygous for what is probably a truncating splice-site mutation (c.4488G-->C), whereas mild RP is present in individuals carrying the homozygous missense mutation R1746Q. A variable expression of the retinal phenotype was seen in patients with a combination of both mutations. In addition, we identified two mutations, Delta M1281 and IVS51+5G-->A, in a German USH1 patient. Our data show that different mutations in CDH23 result in USH1D with a variable retinal phenotype. In an accompanying paper, it is shown that mutations in the mouse ortholog cause disorganization of inner ear stereocilia and deafness in the waltzer mouse.

Stromal Cells Positively and Negatively Modulate the Growth of Cancer Cells: Stimulation via the PGE2-TNFα-IL-6 Pathway and Inhibition via Secreted GAPDH-E-Cadherin Interaction

Science.gov (United States)

Kawada, Manabu; Inoue, Hiroyuki; Ohba, Shun-ichi; Yoshida, Junjiro; Masuda, Tohru; Yamasaki, Manabu; Usami, Ihomi; Sakamoto, Shuichi; Abe, Hikaru; Watanabe, Takumi; Yamori, Takao; Shibasaki, Masakatsu; Nomoto, Akio

2015-01-01

Fibroblast-like stromal cells modulate cancer cells through secreted factors and adhesion, but those factors are not fully understood. Here, we have identified critical stromal factors that modulate cancer growth positively and negatively. Using a cell co-culture system, we found that gastric stromal cells secreted IL-6 as a growth and survival factor for gastric cancer cells. Moreover, gastric cancer cells secreted PGE2 and TNFα that stimulated IL-6 secretion by the stromal cells. Furthermore, we found that stromal cells secreted glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Extracellular GAPDH, or its N-terminal domain, inhibited gastric cancer cell growth, a finding confirmed in other cell systems. GAPDH bound to E-cadherin and downregulated the mTOR-p70S6 kinase pathway. These results demonstrate that stromal cells could regulate cancer cell growth through the balance of these secreted factors. We propose that negative regulation of cancer growth using GAPDH could be a new anti-cancer strategy. PMID:25785838

Direct adaptive control of manipulators in Cartesian space

Science.gov (United States)

Seraji, H.

1987-01-01

A new adaptive-control scheme for direct control of manipulator end effector to achieve trajectory tracking in Cartesian space is developed in this article. The control structure is obtained from linear multivariable theory and is composed of simple feedforward and feedback controllers and an auxiliary input. The direct adaptation laws are derived from model reference adaptive control theory and are not based on parameter estimation of the robot model. The utilization of adaptive feedforward control and the inclusion of auxiliary input are novel features of the present scheme and result in improved dynamic performance over existing adaptive control schemes. The adaptive controller does not require the complex mathematical model of the robot dynamics or any knowledge of the robot parameters or the payload, and is computationally fast for on-line implementation with high sampling rates. The control scheme is applied to a two-link manipulator for illustration.

Static compression down-regulates N-cadherin expression and facilitates loss of cell phenotype of nucleus pulposus cells in a disc perfusion culture.

Science.gov (United States)

Zhou, Haibo; Shi, Jianmin; Zhang, Chao; Li, Pei

2018-02-28

Mechanical compression often induces degenerative changes of disc nucleus pulposus (NP) tissue. It has been indicated that N-cadherin (N-CDH)-mediated signaling helps to preserve the NP cell phenotype. However, N-CDH expression and the resulting NP-specific phenotype alteration under the static compression and dynamic compression remain unclear. To study the effects of static compression and dynamic compression on N-CDH expression and NP-specific phenotype in an in vitro disc organ culture. Porcine discs were organ cultured in a self-developed mechanically active bioreactor for 7 days and subjected to static or dynamic compression (0.4 MPa for 2 h once per day). The noncompressed discs were used as controls. Compared with the dynamic compression, static compression significantly down-regulated the expression of N-CDH and NP-specific markers (laminin, brachyury, and keratin 19); decreased the Alcian Blue staining intensity, glycosaminoglycan and hydroxyproline contents; and declined the matrix macromolecule (aggrecan and collagen II) expression. Compared with the dynamic compression, static compression causes N-CDH down-regulation, loss of NP-specific phenotype, and the resulting decrease in NP matrix synthesis. © 2018 The Author(s).

Directed Assembly of Janus Cylinders by Controlling the Solvent Polarity.

Science.gov (United States)

Kim, Jongmin; Choi, Chang-Hyung; Yeom, Su-Jin; Eom, Naye; Kang, Kyoung-Ku; Lee, Chang-Soo

2017-08-01

This study demonstrates the possibility of controlling the directed self-assembly of microsized Janus cylinders by changing the solvent polarity of the assembly media. Experimental results are analyzed and theoretical calculations of the free energy of adhesion (ΔG ad ) are performed to elucidate the underlying basic principles and investigate the effects of the solvent on the self-assembled structures. This approach will pave a predictive route for controlling the structures of assembly depending on the solvent polarity. In particular, we find that a binary solvent system with precisely controlled polarity induces directional assembly of the microsized Janus cylinders. Thus, the formation of two-dimensional (2D) and three-dimensional (3D) assembled clusters can be reliably tuned by controlling the numbers of constituent Janus cylinders in a binary solvent system. Finally, this approach is expanded to stepwise assembly, which forms unique microstructures via secondary growth of primary seed clusters formed by the Janus cylinders. We envision that this investigation is highly promising for the construction of desired superstructures using a wide variety of polymeric Janus microparticles with chemical and physical multicompartments.

A Randomized Controlled Trial Comparing the Letter Project Advance Directive to Traditional Advance Directive.

Science.gov (United States)

Periyakoil, Vyjeyanthi S; Neri, Eric; Kraemer, Helena

2017-09-01

Simpler alternatives to traditional advance directives that are easy to understand and available in multiple formats and can be initiated by patients and families will help facilitate advance care planning. The goal of this study was to compare the acceptability of the letter advance directive (LAD) to the traditional advance directive (TAD) of the state of California. A web-based, randomized controlled trial was conducted, in which the participants were randomized to one of two types of advance directives (ADs): the LAD (intervention) or the TAD (control). Primary outcomes were participant ratings of the ease, value, and their level of comfort in the AD document they completed. A total of 400 participants completed the study, with 216 randomized to the LAD and 184 to the TAD by a computerized algorithm. Overall, participants preferred the LAD to the TAD (success rate difference [SRD] = 0.46, 95th percentile confidence interval [CI]: 0.36-0.56, p advance directive to be a better alternative to the traditional advance directive form.

Direct output feedback control of discrete-time systems

International Nuclear Information System (INIS)

Lin, C.C.; Chung, L.L.; Lu, K.H.

1993-01-01

An optimal direct output feedback control algorithm is developed for discrete-time systems with the consideration of time delay in control force action. Optimal constant output feedback gains are obtained through variational process such that certain prescribed quadratic performance index is minimized. Discrete-time control forces are then calculated from the multiplication of output measurements by these pre-calculated feedback gains. According to the proposed algorithm, structural system is assured to remain stable even in the presence of time delay. The number of sensors and controllers may be very small as compared with the dimension of states. Numerical results show that direct velocity feedback control is more sensitive to time delay than state feedback but, is still quite effective in reducing the dynamic responses under earthquake excitation. (author)

Direct battery-driven solar LED lighting using constant-power control

KAUST Repository

Huang, Bin-Juine

2012-11-01

A direct battery-driven LED lighting technique using constant-power control is proposed in the present study. A system dynamics model of LED luminaire was derived and used in the design of the feedback constant-power control system. The test result has shown that the power of 18. W and 100. W LED luminaires can be controlled accurately with error at 2-5%. A solar LED street lighting system using constant-power and dimming control was designed and built for field test in a remote area. The long-term performance was satisfactory and no any failure since the installation. Since no high-power capacitor is used in the present constant-power control circuit, a longer lifetime is expected. © 2012 Elsevier Ltd.

Pixel extraction based integral imaging with controllable viewing direction

International Nuclear Information System (INIS)

Ji, Chao-Chao; Deng, Huan; Wang, Qiong-Hua

2012-01-01

We propose pixel extraction based integral imaging with a controllable viewing direction. The proposed integral imaging can provide viewers three-dimensional (3D) images in a very small viewing angle. The viewing angle and the viewing direction of the reconstructed 3D images are controlled by the pixels extracted from an elemental image array. Theoretical analysis and a 3D display experiment of the viewing direction controllable integral imaging are carried out. The experimental results verify the correctness of the theory. A 3D display based on the integral imaging can protect the viewer’s privacy and has huge potential for a television to show multiple 3D programs at the same time. (paper)

Cadherin-23 may be dynamic in hair bundles of the model sea anemone Nematostella vectensis.

Directory of Open Access Journals (Sweden)

Pei-Ciao Tang

Full Text Available Cadherin 23 (CDH23, a component of tip links in hair cells of vertebrate animals, is essential to mechanotransduction by hair cells in the inner ear. A homolog of CDH23 occurs in hair bundles of sea anemones. Anemone hair bundles are located on the tentacles where they detect the swimming movements of nearby prey. The anemone CDH23 is predicted to be a large polypeptide featuring a short exoplasmic C-terminal domain that is unique to sea anemones. Experimentally masking this domain with antibodies or mimicking this domain with free peptide rapidly disrupts mechanotransduction and morphology of anemone hair bundles. The loss of normal morphology is accompanied, or followed by a decrease in F-actin in stereocilia of the hair bundles. These effects were observed at very low concentrations of the reagents, 0.1-10 nM, and within minutes of exposure. The results presented herein suggest that: (1 the interaction between CDH23 and molecular partners on stereocilia of hair bundles is dynamic and; (2 the interaction is crucial for normal mechanotransduction and morphology of hair bundles.

Integrin-linked kinase and ELMO2 modulate recycling endosomes in keratinocytes.

Science.gov (United States)

Ho, Ernest; Ivanova, Iordanka A; Dagnino, Lina

2016-12-01

The formation of tight cell-cell junctions is essential in the epidermis for its barrier properties. In this tissue, keratinocytes follow a differentiation program tightly associated with their movement from the innermost basal to the outer suprabasal layers, and with changes in their cell-cell adhesion profile. Intercellular adhesion in keratinocytes is mediated through cell-cell contacts, including E-cadherin-based adherens junctions. Although the mechanisms that mediate E-cadherin delivery to the plasma membrane have been widely studied in simple epithelia, this process is less well understood in the stratified epidermis. In this study, we have investigated the role of Engulfment and Cell Motility 2 (ELMO2) and integrin-linked kinase (ILK) in the positioning of E-cadherin-containing recycling endosomes during establishment of cell-cell contacts in differentiating keratinocytes. We now show that induction of keratinocyte differentiation by Ca 2+ is accompanied by localization of ELMO2 and ILK to Rab4- and Rab11a-containing recycling endosomes. The positioning of long-loop Rab11a-positive endosomes at areas adjacent to cell-cell contacts is disrupted in ELMO2- or ILK-deficient keratinocytes, and is associated with impaired localization of E-cadherin to cell borders. Our studies show a previously unrecognized role for ELMO2 and ILK in modulation of endosomal positioning, which may play key roles in epidermal sheet maintenance and permeability barrier function. Copyright © 2016 Elsevier B.V. All rights reserved.

Multiparty-controlled quantum secure direct communication

International Nuclear Information System (INIS)

Xiu, X.-M.; Dong, L.; Gao, Y.-J.; Chi, F.

2007-01-01

A theoretical scheme of a multiparty-controlled quantum secure direct communication is proposed. The supervisor prepares a communication network with Einstein-Podolsky-Rosen pairs and auxiliary particles. After passing a security test of the communication network, a supervisor tells the users the network is secure and they can communicate. If the controllers allow the communicators to communicate, the controllers should perform measurements and inform the communicators of the outcomes. The communicators then begin to communicate after they perform a security test of the quantum channel and verify that it is secure. The recipient can decrypt the secret message in a classical message from the sender depending on the protocol. Any two users in the network can communicate through the above processes under the control of the supervisor and the controllers

Controlled and secure direct communication using GHZ state and teleportation

International Nuclear Information System (INIS)

Gao, T.

2004-01-01

A theoretical scheme for controlled and secure direct communication is proposed. The communication is based on GHZ state and controlled quantum teleportation. After insuring the security of the quantum channel (a set of qubits in the GHZ state), alice encodes the secret message directly on a sequence of particle states in the GHZ state and transmits them to Bob, supervised by Charlie using controlled quantum teleportation. Bob can read out the encoded messages directly by the measurement on his qubits. In this scheme, the controlled quantum teleportation transmits alice's message without revealing any information to a potential eavesdropper. Because there is not a transmission of the qubit carrying the secret messages between Alice and Bob in the public channel, it is completely secure for controlled and direct secret communication if a perfect quantum channel is used. The feature of this scheme is that the communication between two sides depends on the agreement of a third side. (orig.)

Direct Torque Control of a Small Wind Turbine with a Sliding-Mode Speed Controller

Science.gov (United States)

Sri Lal Senanayaka, Jagath; Karimi, Hamid Reza; Robbersmyr, Kjell G.

2016-09-01

In this paper. the method of direct torque control in the presence of a sliding-mode speed controller is proposed for a small wind turbine being used in water heating applications. This concept and control system design can be expanded to grid connected or off-grid applications. Direct torque control of electrical machines has shown several advantages including very fast dynamics torque control over field-oriented control. Moreover. the torque and flux controllers in the direct torque control algorithms are based on hvsteretic controllers which are nonlinear. In the presence of a sliding-mode speed control. a nonlinear control system can be constructed which is matched for AC/DC conversion of the converter that gives fast responses with low overshoots. The main control objectives of the proposed small wind turbine can be maximum power point tracking and soft-stall power control. This small wind turbine consists of permanent magnet synchronous generator and external wind speed. and rotor speed measurements are not required for the system. However. a sensor is needed to detect the rated wind speed overpass events to activate proper speed references for the wind turbine. Based on the low-cost design requirement of small wind turbines. an available wind speed sensor can be modified. or a new sensor can be designed to get the required measurement. The simulation results will be provided to illustrate the excellent performance of the closed-loop control system in entire wind speed range (4-25 m/s).

Comparison of pulsed fluoroscopy by direct control using a grid-controlled x-ray tube with pulsed fluoroscopy by primary control

International Nuclear Information System (INIS)

Chida, Koichi; Zuguchi, Masayuki; Ito, Daisuke; Sato, Kunihiko; Shimura, Hirotaka; Sasaki, Masatoshi

2001-01-01

Interventional radiology (IVR) procedures may involve high radiation doses that are potentially harmful to the patient. In IVR procedures, pulsed fluoroscopy can greatly decrease the radiation that the physician and patient receive. There are two types of pulsed fluoroscopy: direct control and primary (indirect) control. The purpose of this study was to compare pulsed fluoroscopy by direct control, using a grid-controlled x-ray tube, with pulsed fluoroscopy using primary control. For both types of pulsed fluoroscopy, we measured the waveforms (x-ray tube voltage, x-ray tube current, and x-ray output) and the relative radiation dose. In addition, we compared the decrease in radiation during pulsed fluoroscopy using a care filter. The studies were performed using a Siemens Bicor Plus x-ray System (direct control) and a Siemens Multistar Plus x-ray System (primary control). Using primary pulse control, a 50% decrease in the x-ray output waveform took approximately 0.5-1.0 msec, or longer with a lower x-ray tube current. Using direct pulse control, a 50% decrease in the x-ray output waveform took approximately 0.1 msec, and was independent of x-ray tube current. The rate of radiation reduction with primary pulse control using the care filter with a lower x-ray tube current had a slope exceeding 10%. Pulsed fluoroscopy by direct control using a grid-controlled x-ray tube permits an optimal radiation dose. To decrease the radiation in primary pulse control, a care filter must be used, particularly with a lower x-ray tube current. (author)

Quantum computation via local control theory: Direct sum vs. direct product Hilbert spaces

International Nuclear Information System (INIS)

Sklarz, Shlomo E.; Tannor, David J.

2006-01-01

The central objective in any quantum computation is the creation of a desired unitary transformation; the mapping that this unitary transformation produces between the input and output states is identified with the computation. In [S.E. Sklarz, D.J. Tannor, arXiv:quant-ph/0404081 (submitted to PRA) (2004)] it was shown that local control theory can be used to calculate fields that will produce such a desired unitary transformation. In contrast with previous strategies for quantum computing based on optimal control theory, the local control scheme maintains the system within the computational subspace at intermediate times, thereby avoiding unwanted decay processes. In [S.E. Sklarz et al.], the structure of the Hilbert space had a direct sum structure with respect to the computational register and the mediating states. In this paper, we extend the formalism to the important case of a direct product Hilbert space. The final equations for the control algorithm for the two cases are remarkably similar in structure, despite the fact that the derivations are completely different and that in one case the dynamics is in a Hilbert space and in the other case the dynamics is in a Liouville space. As shown in [S.E. Sklarz et al.], the direct sum implementation leads to a computational mechanism based on virtual transitions, and can be viewed as an extension of the principles of Stimulated Raman Adiabatic Passage from state manipulation to evolution operator manipulation. The direct product implementation developed here leads to the intriguing concept of virtual entanglement - computation that exploits second-order transitions that pass through entangled states but that leaves the subsystems nearly separable at all intermediate times. Finally, we speculate on a connection between the algorithm developed here and the concept of decoherence free subspaces

Clinical value of detection on ser um monocyte chemotactant protein-1 and vascular endothelial cadher in levels in patients with acute cerebral infarction

Directory of Open Access Journals (Sweden)

Xia Zhou

2016-11-01

Full Text Available Objective: To study the correlation of serum monocyte chemotactant protein-1 (MCP-1 and vascular endothelia cadherin (VE-cadherin levels in patients with acute cerebral infarction, and nerve injury molecules, interleukins and matrix metalloproteinases. Methods: A total of 86 patients with acute cerebral infarction treated in our hospital from April 2012 to October 2015 were selected as the observation group and 50 healthy subjects in the same period treated in our hospital were selected as the control group. The serums were collected and the contents of MCP-1, VE-cadherin, heart-type fatty acid binding protein (H-FABP, S100 calcium binding protein B (S100B, neuron-specific enolase (NSE, interleukin-lb (IL-1b, IL-6, IL-17, IL-18, matrix metalloproteinase-2 (MMP2, MMP3 and MMP9 were measured. Results: The serum contents of MCP-1, VE-cadherin, H-FABP, S100B, NSE, IL-1b, IL- 6, IL-17, IL-18, MMP2, MMP3 and MMP9 in observation group were significantly higher than those of control group. Carotid artery plaque formation and unstable plaque properties will increase the serum contents of MCP-1, VE-cadherin, H-FABP, S100B, NSE, IL-1b, IL-6, IL-17, IL-18, MMP2, MMP3 and MMP9 in patients with cerebral infarction. The serum levels of MCP-1, VE-cadherin and the contents of H-FABP, S100B, NSE, IL-1b, IL-6, IL-17, IL-18, MMP2, MMP3 and MMP9 were positively correlated. Conclusions: The serum levels of VE-cadherin and MCP-1 were significantly increased in patients with acute cerebral infarction. MCP-1 and VE-cadherin can increase the secretion of interleukins and matrix metalloproteinases, which can result in the carotid artery plaque formation, unstable plaque properties and the injury of nerve function.

Application of Space Vector Modulation in Direct Torque Control of PMSM

Directory of Open Access Journals (Sweden)

Michal Malek

2008-01-01

Full Text Available The paper deals with an improvement of direct torque control method for permanent magnet synchronous motor drives. Electrical torque distortion of the machine under original direct torque control is relatively high and if proper measures are taken it can be substantially decreased. The proposed solution here is to combine direct torque control with the space vector modulation technique. Such approach can eliminate torque distortion while preserving the simplicity of the original method.

A real-time comparison between direct control, sequential pattern recognition control and simultaneous pattern recognition control using a Fitts' law style assessment procedure.

Science.gov (United States)

Wurth, Sophie M; Hargrove, Levi J

2014-05-30

Pattern recognition (PR) based strategies for the control of myoelectric upper limb prostheses are generally evaluated through offline classification accuracy, which is an admittedly useful metric, but insufficient to discuss functional performance in real time. Existing functional tests are extensive to set up and most fail to provide a challenging, objective framework to assess the strategy performance in real time. Nine able-bodied and two amputee subjects gave informed consent and participated in the local Institutional Review Board approved study. We designed a two-dimensional target acquisition task, based on the principles of Fitts' law for human motor control. Subjects were prompted to steer a cursor from the screen center of into a series of subsequently appearing targets of different difficulties. Three cursor control systems were tested, corresponding to three electromyography-based prosthetic control strategies: 1) amplitude-based direct control (the clinical standard of care), 2) sequential PR control, and 3) simultaneous PR control, allowing for a concurrent activation of two degrees of freedom (DOF). We computed throughput (bits/second), path efficiency (%), reaction time (second), and overshoot (%)) and used general linear models to assess significant differences between the strategies for each metric. We validated the proposed methodology by achieving very high coefficients of determination for Fitts' law. Both PR strategies significantly outperformed direct control in two-DOF targets and were more intuitive to operate. In one-DOF targets, the simultaneous approach was the least precise. The direct control was efficient in one-DOF targets but cumbersome to operate in two-DOF targets through a switch-depended sequential cursor control. We designed a test, capable of comprehensively describing prosthetic control strategies in real time. When implemented on control subjects, the test was able to capture statistically significant differences (p�

Zener diode controls switching of large direct currents

Science.gov (United States)

1965-01-01

High-current zener diode is connected in series with the positive input terminal of a dc supply to block the flow of direct current until a high-frequency control signal is applied across the zener diode. This circuit controls the switching of large dc signals.

Potential of Targeting PDE1C/2A for Suppressing Metastatic Ovarian Cancers

Science.gov (United States)

2015-09-01

HGSOC), are marked by profound chromosomal aberrations (gene amplification and loss) rather than recurrent somatic mutations [2-4...forced expression resulted in the induction of vimentin and disappearance of E-cadherin in these cells (Figure 1e). Moreover, these cells became...dramatic increase in the abundance of E-cadherin and disappearance of vimentin in both lines (Figure 5b). In addition, mesenchymal morphology of OVCAR5

Tryptophan Depletion Promotes Habitual over Goal-Directed Control of Appetitive Responding in Humans.

Science.gov (United States)

Worbe, Yulia; Savulich, George; de Wit, Sanne; Fernandez-Egea, Emilio; Robbins, Trevor W

2015-02-05

Optimal behavioral performance results from a balance between goal-directed and habitual systems of behavioral control, which are modulated by ascending monoaminergic projections. While the role of the dopaminergic system in behavioral control has been recently addressed, the extent to which changes in global serotonin neurotransmission could influence these 2 systems is still poorly understood. We employed the dietary acute tryptophan depletion procedure to reduce serotonin neurotransmission in 18 healthy volunteers and 18 matched controls. We used a 3-stage instrumental learning paradigm that includes an initial instrumental learning stage, a subsequent outcome-devaluation test, and a slip-of-action stage, which directly tests the balance between hypothetical goal-directed and habitual systems. We also employed a separate response inhibition control test to assess the behavioral specificity of the results. Acute tryptophan depletion produced a shift of behavioral performance towards habitual responding as indexed by performance on the slip-of-action test. Moreover, greater habitual responding in the acute tryptophan depletion group was predicted by a steeper decline in plasma tryptophan levels. In contrast, acute tryptophan depletion left intact the ability to use discriminative stimuli to guide instrumental choice as indexed by the instrumental learning stage and did not impair inhibitory response control. The major implication of this study is that serotonin modulates the balance between goal-directed and stimulus-response habitual systems of behavioral control. Our findings thus imply that diminished serotonin neurotransmission shifts behavioral control towards habitual responding. © The Author 2015. Published by Oxford University Press on behalf of CINP.

Regulation of human feto-placental endothelial barrier integrity by vascular endothelial growth factors: competitive interplay between VEGF-A165a, VEGF-A165b, PIGF and VE-cadherin.

Science.gov (United States)

Pang, Vincent; Bates, David O; Leach, Lopa

2017-12-01

The human placenta nourishes and protects the developing foetus whilst influencing maternal physiology for fetal advantage. It expresses several members of the vascular endothelial growth factor (VEGF) family including the pro-angiogenic/pro-permeability VEGF-A 165 a isoform, the anti-angiogenic VEGF-A 165 b, placental growth factor (PIGF) and their receptors, VEGFR1 and VEGFR2. Alterations in the ratio of these factors during gestation and in complicated pregnancies have been reported; however, the impact of this on feto-placental endothelial barrier integrity is unknown. The present study investigated the interplay of these factors on junctional occupancy of VE-cadherin and macromolecular leakage in human endothelial monolayers and the perfused placental microvascular bed. Whilst VEGF-A 165 a (50 ng/ml) increased endothelial monolayer albumin permeability ( P 0.05) or PlGF ( P >0.05) did not. Moreover, VEGF-A 165 b (100 ng/ml; P 0.05) inhibited VEGF-A 165 a-induced permeability when added singly. PlGF abolished the VEGF-A 165 b-induced reduction in VEGF-A 165 a-mediated permeability ( P >0.05); PlGF was found to compete with VEGF-A 165 b for binding to Flt-1 at equimolar affinity. Junctional occupancy of VE-cadherin matched alterations in permeability. In the perfused microvascular bed, VEGF-A 165 b did not induce microvascular leakage but inhibited and reversed VEGF-A 165 a-induced loss of junctional VE-cadherin and tracer leakage. These results indicate that the anti-angiogenic VEGF-A 165 b isoform does not increase permeability in human placental microvessels or HUVEC primary cells and can interrupt VEGF-A 165 a-induced permeability. Moreover, the interplay of these isoforms with PIGF (and s-flt1) suggests that the ratio of these three factors may be important in determining the placental and endothelial barrier in normal and complicated pregnancies. © 2017 The Author(s).

DISTRIBUTED CONTROL ARCHITECTURE OF AN OMNI-DIRECTIONAL AUTONOMOUS GUIDED VEHICLE

Directory of Open Access Journals (Sweden)

N.S. Tlale

2012-01-01

Full Text Available

ENGLISH ABSTRACT: Omni-directionality is the ability of a mobile robot to move instantaneously in any direction. This paper describes the wheel and controller designs of a Mecanumwheeled, autonomous guided vehicle (AGV for reconfigurable manufacturing systems. Mecanum wheels use slip developed between rollers and surface, surface and ground, to achieve omni-directionality. An advantage of omni-directional robotic platforms is that they are capable of performing tasks in congested environments such as those found in factory workshops, narrow aisles, warehouses, etc. Controller Area Network (CAN is implemented as a distributed controller to control motion and navigation tasks of the developed robot. The design of the distributed controller is described and its performance analyzed. This increases the reliability and functionality of the mobile robot.

AFRIKAANSE OPSOMMING: Die artikel beskryf wiel - en beheerontwerpe van ‘n veelrigting mobiele robot. Die robot is ‘n selfstandigbeheerde voertuig vir gebruik by vervaardigingstelsels met veranderbare konfigurasie. Die ontwerp van die robot en bypassende beheerstelsel word beskryf en ontleed teen die agterground van bewegings – en navigeertake. Die betroubaarheid en funksionering van die sisteem word beoordeel.

The Crosstalk between Nrf2 and TGF-β1 in the Epithelial-Mesenchymal Transition of Pancreatic Duct Epithelial Cells.

Directory of Open Access Journals (Sweden)

Sarah Arfmann-Knübel

Full Text Available Nrf2 and TGF-β1 both affect tumorigenesis in a dual fashion, either by preventing carcinogen induced carcinogenesis and suppressing tumor growth, respectively, or by conferring cytoprotection and invasiveness to tumor cells during malignant transformation. Given the involvement of Nrf2 and TGF-β1 in the adaptation of epithelial cells to persistent inflammatory stress, e.g. of the pancreatic duct epithelium during chronic pancreatitis, a crosstalk between Nrf2 and TGF-β1 can be envisaged. By using premalignant human pancreatic duct cells (HPDE and the pancreatic ductal adenocarcinoma cell line Colo357, we could show that Nrf2 and TGF-β1 independently but additively conferred an invasive phenotype to HPDE cells, whereas acting synergistically in Colo357 cells. This was accompanied by differential regulation of EMT markers like vimentin, Slug, L1CAM and E-cadherin. Nrf2 activation suppressed E-cadherin expression through an as yet unidentified ARE related site in the E-cadherin promoter, attenuated TGF-β1 induced Smad2/3-activity and enhanced JNK-signaling. In Colo357 cells, TGF-β1 itself was capable of inducing Nrf2 whereas in HPDE cells TGF-β1 per-se did not affect Nrf2 activity, but enhanced Nrf2 induction by tBHQ. In Colo357, but not in HPDE cells, the effects of TGF-β1 on invasion were sensitive to Nrf2 knock-down. In both cell lines, E-cadherin re-expression inhibited the proinvasive effect of Nrf2. Thus, the increased invasion of both cell lines relates to the Nrf2-dependent downregulation of E-cadherin expression. In line, immunohistochemistry analysis of human pancreatic intraepithelial neoplasias in pancreatic tissues from chronic pancreatitis patients revealed strong Nrf2 activity already in premalignant epithelial duct cells, accompanied by partial loss of E-cadherin expression. Our findings indicate that Nrf2 and TGF-β1 both contribute to malignant transformation through distinct EMT related mechanisms accounting for an

AmbiGaze : direct control of ambient devices by gaze

OpenAIRE

Velloso, Eduardo; Wirth, Markus; Weichel, Christian; Abreu Esteves, Augusto Emanuel; Gellersen, Hans-Werner Georg

2016-01-01

Eye tracking offers many opportunities for direct device control in smart environments, but issues such as the need for calibration and the Midas touch problem make it impractical. In this paper, we propose AmbiGaze, a smart environment that employs the animation of targets to provide users with direct control of devices by gaze only through smooth pursuit tracking. We propose a design space of means of exposing functionality through movement and illustrate the concept through four prototypes...

Discovery of an O-mannosylation pathway selectively serving cadherins and protocadherins.

Science.gov (United States)

Larsen, Ida Signe Bohse; Narimatsu, Yoshiki; Joshi, Hiren Jitendra; Siukstaite, Lina; Harrison, Oliver J; Brasch, Julia; Goodman, Kerry M; Hansen, Lars; Shapiro, Lawrence; Honig, Barry; Vakhrushev, Sergey Y; Clausen, Henrik; Halim, Adnan

2017-10-17

The cadherin (cdh) superfamily of adhesion molecules carry O-linked mannose (O-Man) glycans at highly conserved sites localized to specific β-strands of their extracellular cdh (EC) domains. These O-Man glycans do not appear to be elongated like O-Man glycans found on α-dystroglycan (α-DG), and we recently demonstrated that initiation of cdh/protocadherin (pcdh) O-Man glycosylation is not dependent on the evolutionary conserved POMT1/POMT2 enzymes that initiate O-Man glycosylation on α-DG. Here, we used a CRISPR/Cas9 genetic dissection strategy combined with sensitive and quantitative O-Man glycoproteomics to identify a homologous family of four putative protein O-mannosyltransferases encoded by the TMTC1-4 genes, which were found to be imperative for cdh and pcdh O-Man glycosylation. KO of all four TMTC genes in HEK293 cells resulted in specific loss of cdh and pcdh O-Man glycosylation, whereas combined KO of TMTC1 and TMTC3 resulted in selective loss of O-Man glycans on specific β-strands of EC domains, suggesting that each isoenzyme serves a different function. In addition, O-Man glycosylation of IPT/TIG domains of plexins and hepatocyte growth factor receptor was not affected in TMTC KO cells, suggesting the existence of yet another O-Man glycosylation machinery. Our study demonstrates that regulation of O-mannosylation in higher eukaryotes is more complex than envisioned, and the discovery of the functions of TMTCs provide insight into cobblestone lissencephaly caused by deficiency in TMTC3.

Sleep Deprivation Promotes Habitual Control over Goal-Directed Control: Behavioral and Neuroimaging Evidence.

Science.gov (United States)

Chen, Jie; Liang, Jie; Lin, Xiao; Zhang, Yang; Zhang, Yan; Lu, Lin; Shi, Jie

2017-12-06

Sleep is one of the most fundamental processes of life, playing an important role in the regulation of brain function. The long-term lack of sleep can cause memory impairments, declines in learning ability, and executive dysfunction. In the present study, we evaluated the effects of sleep deprivation on instrumental learning behavior, particularly goal-directed and habitual actions in humans, and investigated the underlying neural mechanisms. Healthy college students of either gender were enrolled and randomly divided into sleep deprivation group and sleep control group. fMRI data were collected. We found that one night of sleep deprivation led to greater responsiveness to stimuli that were associated with devalued outcomes in the slips-of-action test, indicating a deficit in the formation of goal-directed control and an overreliance on habits. Furthermore, sleep deprivation had no effect on the expression of acquired goal-directed action. The level of goal-directed action after sleep deprivation was positively correlated with baseline working memory capacity. The neuroimaging data indicated that goal-directed learning mainly recruited the ventromedial PFC (vmPFC), the activation of which was less pronounced during goal-directed learning after sleep deprivation. Activation of the vmPFC during goal-directed learning during training was positively correlated with the level of goal-directed action performance. The present study suggests that people rely predominantly on habits at the expense of goal-directed control after sleep deprivation, and this process involves the vmPFC. These results contribute to a better understanding of the effects of sleep loss on decision-making. SIGNIFICANCE STATEMENT Understanding the cognitive consequences of sleep deprivation has become extremely important over the past half century, given the continued decline in sleep duration in industrialized societies. Our results provide novel evidence that goal-directed action may be

The efficiency of direct torque control for electric vehicle behavior improvement

Directory of Open Access Journals (Sweden)

Gasbaoui Brahim

2011-01-01

Full Text Available Nowadays the electric vehicle motorization control takes a great interest of industrials for commercialized electric vehicles. This paper is one example of the proposed control methods that ensure both safety and stability the electric vehicle by the means of Direct Torque Control (DTC. For motion of the vehicle the electric drive consists of four wheels: two front ones for steering and two rear ones for propulsion equipped with two induction motors, due to their lightweight simplicity and high performance. Acceleration and steering are ensured by the electronic differential, permitting safe and reliable steering at any curve. The direct torque control ensures efficiently controlled vehicle. Electric vehicle direct torque control is simulated in MATLAB SIMULINK environment. Electric vehicle (EV demonstrated satisfactory results in all type of roads constraints: straight, ramp, downhill and bends.

Direct Model Reference Adaptive Control for a Magnetic Bearing

Energy Technology Data Exchange (ETDEWEB)

Durling, Mike [Rensselaer Polytechnic Inst., Troy, NY (United States)

1999-11-01

A Direct Model Reference Adaptive Controller (DMRAC) is applied to a magnetic bearing test stand. The bearing of interest is the MBC 500 Magnetic Bearing System manufactured by Magnetic Moments, LLC. The bearing model is presented in state space form and the system transfer function is measured directly using a closed-loop swept sine technique. Next, the bearing models are used to design a phase-lead controller, notch filter and then a DMRAC. The controllers are tuned in simulations and finally are implemented using a combination of MATLAB, SIMULINK and dSPACE. The results show a successful implementation of a DMRAC on the magnetic bearing hardware.

Multifunctional four-port directional control valve constructed from logic valves

International Nuclear Information System (INIS)

Lisowski, E.; Czyżycki, W.; Rajda, J.

2014-01-01

Highlights: • Directional valve with standard ISO 440-08 has been constructed from logic valves. • Only one innovative valve may replace whole family of the standard valves. • CFD analysis and bench tests of the innovative valve has been carried. • Parameters of the innovative valve are equaling or surpassing the standard ones. • The innovative valve has additional possibilities of pressure and flow control. - Abstract: The paper refers to four-port solenoid pilot operated valves, which are subplate mounted in a hydraulic system in accordance with the ISO 4401 standard. Their widespread use in many machines and devices causes a continuing interest in the development of their design by both the scientific centers and the industry. This paper presents an innovative directional control valve based on the use of logic valves and a methodology followed for the design of it by using Solid Edge CAD and ANSYS/Fluent CFD software. The valve design methodology takes into account the need to seek solutions that minimize flow resistance through the valve. For this purpose, the flow paths are prepared by means of CAD software and pressure-flow curves are determined as a result of CFD analysis. The obtained curves are compared with the curves available in the catalogs of spool type directional control valves. The new solution allows to replace the whole family of spool type four-port directional control valves by one valve built of logic valves. In addition, the innovative directional control valve provides leak-proof shutting the flow paths off and also it can control flow rate and even pressure of working liquid. A prototype of the valve designed by the presented method has been made and tested on the test bench. The results quoted in the paper confirm that the developed logic type directional control valve is able to meet all designed connection configurations, and the obtained pressure-flow curves show very good conformity with the results of CFD analysis

Generating size-controlled embryoid bodies using laser direct-write

International Nuclear Information System (INIS)

Dias, A D; Corr, D T; Unser, A M; Xie, Y; Chrisey, D B

2014-01-01

Embryonic stem cells (ESCs) have the potential to self-renew and differentiate into any specialized cell type. One common method to differentiate ESCs in vitro is through embryoid bodies (EBs), three-dimensional cellular aggregates that spontaneously self-assemble and generally express markers for the three germ layers, endoderm, ectoderm, and mesoderm. It has been previously shown that both EB size and 2D colony size each influence differentiation. We hypothesized that we could control the size of the EB formed by mouse ESCs (mESCs) by using a cell printing method, laser direct-write (LDW), to control both the size of the initial printed colony and the local cell density in printed colonies. After printing mESCs at various printed colony sizes and printing densities, two-way ANOVAs indicated that the EB diameter was influenced by printing density after three days (p = 0.0002), while there was no effect of the printed colony diameter on the EB diameter at the same timepoint (p = 0.74). There was no significant interaction between these two factors. Tukey's honestly significant difference test showed that high-density colonies formed significantly larger EBs, suggesting that printed mESCs quickly aggregate with nearby cells. Thus, EBs can be engineered to a desired size by controlling printing density, which will influence the design of future differentiation studies. Herein, we highlight the capacity of LDW to control the local cell density and colony size independently, at prescribed spatial locations, potentially leading to better stem cell maintenance and directed differentiation. (paper)

Construction and direct electrochemistry of orientation controlled laccase electrode.

Science.gov (United States)

Li, Ying; Zhang, Jiwei; Huang, Xirong; Wang, Tianhong

2014-03-28

A laccase has multiple redox centres. Chemisorption of laccases on a gold electrode through a polypeptide tag introduced at the protein surface provides an isotropic orientation of laccases on the Au surface, which allows the orientation dependent study of the direct electrochemistry of laccase. In this paper, using genetic engineering technology, two forms of recombinant laccase which has Cys-6×His tag at the N or C terminus were generated. Via the Au-S linkage, the recombinant laccase was assembled orientationally on gold electrode. A direct electron transfer and a bioelectrocatalytic activity toward oxygen reduction were observed on the two orientation controlled laccase electrodes, but their electrochemical behaviors were found to be quite different. The orientation of laccase on the gold electrode affects both the electron transfer pathway and the electron transfer efficiency of O2 reduction. The present study is helpful not only to the in-depth understanding of the direct electrochemistry of laccase, but also to the development of laccase-based biofuel cells. Copyright © 2014 Elsevier Inc. All rights reserved.

Conventional and novel control designs for direct driven PMSG wind turbines

Energy Technology Data Exchange (ETDEWEB)

Li, Shuhui; Haskew, Timothy A.; Xu, Ling [Department of Electrical and Computer Engineering, The University of Alabama, 317 Houser Hall, Tuscaloosa, AL 35487 (United States)

2010-03-15

With the advance of power electronic technology, direct driven permanent magnet synchronous generators (PMSG) have increasingly drawn interests to wind turbine manufactures. This paper studies and compares conventional and a novel control designs for a direct driven PMSG wind turbine. The paper presents transient and steady-state models of a PMSG system in a d-q reference frame. Then, general PMSG characteristics are investigated in the rotor-flux-oriented frame. A shortage of conventional control mechanisms is studied analytically and through computer simulation. A novel direct-current based d-q vector control technique is proposed by integrating fuzzy, adaptive and traditional PID control technologies in an optimal control configuration. Comparison study demonstrates that the proposed control approach, having superior performance in various aspects, is effective not only in achieving desired PMSG control objectives but also in improving the optimal performance of the overall system. (author)

Multiple Property Cross Direction Control of Paper Machines

Directory of Open Access Journals (Sweden)

Markku Ohenoja

2011-07-01

Full Text Available Cross direction (CD control in sheet-forming process forms a challenging problem with high dimensions. Accounting the interactions between different properties and actuators, the dimensionality increases further and also computational issues arise. We present a multiple property controller feasible to be used especially with imaging measurements that provide high sampling frequency and therefore enable short control interval. The simulation results state the benefits of multiple property CD control over single property control and single property control using full feedforward compensation. The controller presented may also be tuned in automated manner and the results demonstrate the effect of tuning on input saturation.

Subfemtosecond directional control of chemical processes in molecules

Science.gov (United States)

Alnaser, Ali S.; Litvinyuk, Igor V.

2017-02-01

Laser pulses with a waveform-controlled electric field and broken inversion symmetry establish the opportunity to achieve directional control of molecular processes on a subfemtosecond timescale. Several techniques could be used to break the inversion symmetry of an electric field. The most common ones include combining a fundamental laser frequency with its second harmonic or with higher -frequency pulses (or pulse trains) as well as using few-cycle pulses with known carrier-envelope phase (CEP). In the case of CEP, control over chemical transformations, typically occurring on a timescale of many femtoseconds, is driven by much faster sub-cycle processes of subfemtosecond to few-femtosecond duration. This is possible because electrons are much lighter than nuclei and fast electron motion is coupled to the much slower nuclear motion. The control originates from populating coherent superpositions of different electronic or vibrational states with relative phases that are dependent on the CEP or phase offset between components of a two-color pulse. In this paper, we review the recent progress made in the directional control over chemical processes, driven by intense few-cycle laser pulses a of waveform-tailored electric field, in different molecules.

Media bias under direct and indirect government control: when is the bias smaller?

OpenAIRE

Abhra Roy

2015-01-01

We present an analytical framework to compare media bias under direct and indirect government control. In this context, we show that direct control can lead to a smaller bias and higher welfare than indirect control. We further show that the size of the advertising market affects media bias only under direct control. Media bias, under indirect control, is not affected by the size of the advertising market.

Direct and indirect controls of the interannual variability in atmospheric CO₂ exchange of three contrasting ecosystems in Denmark

DEFF Research Database (Denmark)

Jensen, Rasmus; Herbst, Mathias; Friborg, Thomas

2017-01-01

neighboring sites (agriculture, forest, and meadow) subjected to management in variable degree were evaluated to determine typical CO2 budgets and controlling factors of IAV. In terms of average annual net ecosystem exchange (NEE) the agricultural and wet meadow site showed identical rates of −156 (±110...... sources of IAV of CO2 fluxes between direct climatic effects and indirect effects (functional changes). This analysis showed that NEE at the forest (through both GPP and RE) was most prone to interannual functional changes. The wet meadow showed moderate functional changes with respect to RE and thus NEE...

Characterizing Metastatic HER2-Positive Gastric Cancer at the CDH1 Haplotype

Science.gov (United States)

Caggiari, Laura; Miolo, Gianmaria; Buonadonna, Angela; Basile, Debora; Santeufemia, Davide A.; De Zorzi, Mariangela; Fornasarig, Mara; Alessandrini, Lara; Lo Re, Giovanni; Puglisi, Fabio; Steffan, Agostino

2017-01-01

The CDH1 gene, coding for the E-cadherin protein, is linked to gastric cancer (GC) susceptibility and tumor invasion. The human epidermal growth factor receptor 2 (HER2) is amplified and overexpressed in a portion of GC. HER2 is an established therapeutic target in metastatic GC (mGC). Trastuzumab, in combination with various chemotherapeutic agents, is a standard treatment for these tumors leading to outcome improvement. Unfortunately, the survival benefit is limited to a fraction of patients. The aim of this study was to improve knowledge of the HER2 and the E-cadherin alterations in the context of GC to characterize subtypes of patients that could better benefit from targeted therapy. An association between the P7-CDH1 haplotype, including two polymorphisms (rs16260A-rs1801552T) and a subset of HER2-positive mGC with better prognosis was observed. Results indicated the potential evaluation of CDH1 haplotypes in mGC to stratify patients that will benefit from trastuzumab-based treatments. Moreover, data may have implications to understanding the HER2 and the E-cadherin interactions in vivo and in response to treatments. PMID:29295527

Controllability of Weighted and Directed Networks with Nonidentical Node Dynamics

Directory of Open Access Journals (Sweden)

Linying Xiang

2013-01-01

Full Text Available The concept of controllability from control theory is applied to weighted and directed networks with heterogenous linear or linearized node dynamics subject to exogenous inputs, where the nodes are grouped into leaders and followers. Under this framework, the controllability of the controlled network can be decomposed into two independent problems: the controllability of the isolated leader subsystem and the controllability of the extended follower subsystem. Some necessary and/or sufficient conditions for the controllability of the leader-follower network are derived based on matrix theory and graph theory. In particular, it is shown that a single-leader network is controllable if it is a directed path or cycle, but it is uncontrollable for a complete digraph or a star digraph in general. Furthermore, some approaches to improving the controllability of a heterogenous network are presented. Some simulation examples are given for illustration and verification.

Offset-Free Direct Power Control of DFIG Under Continuous-Time Model Predictive Control

DEFF Research Database (Denmark)

Errouissi, Rachid; Al-Durra, Ahmed; Muyeen, S.M.

2017-01-01

This paper presents a robust continuous-time model predictive direct power control for doubly fed induction generator (DFIG). The proposed approach uses Taylor series expansion to predict the stator current in the synchronous reference frame over a finite time horizon. The predicted stator current...... is directly used to compute the required rotor voltage in order to minimize the difference between the actual stator currents and their references over the predictive time. However, as the proposed strategy is sensitive to parameter variations and external disturbances, a disturbance observer is embedded...... into the control loop to remove the steady-state error of the stator current. It turns out that the steady-state and the transient performances can be identified by simple design parameters. In this paper, the reference of the stator current is directly calculated from the desired stator active and reactive powers...

Negative correlation of LIV-1 and E-cadherin expression in hepatocellular carcinoma cells.

Directory of Open Access Journals (Sweden)

Rongxi Shen

Full Text Available LIV-1, a zinc transporter, is a mediator downstream of STAT3 both in zebrafish and mammalian cells, and is involved in epithelial-mesenchymal transition (EMT. Despite LIV-1 participates in cancer growth and metastasis, little is known about the association of LIV-1 with human liver cancer development. Therefore, the expression of LIV-1 mRNA was analyzed by reverse transcriptase polymerase chain reaction (RT-PCR in 4 cultured cell lines (3 carcinoma and 1 normal liver cell lines, and the localization of LIV-1 protein was investigated by immunohistochemistry. Expression of LIV-1 protein was analyzed by Western blot both in 4 cultured cell lines and 120 liver tissues (100 carcinoma and 20 histologically normal tissues, and the relationship between its expression and clinicopathological finding was investigated in 100 hepatocellular carcinoma(HCC tissues. Then stable siRNA expressing Hep-G2 cells were generated to assess the function of LIV-1 in liver cancer cells. We found that LIV-1 mRNA was more highly expressed in liver cancer cell lines compared to normal liver cell line. Western blot showed the expression of LIV-1 was higher in 61% liver carcinoma tissues than that in normal liver tissues. Down-regulated LIV-1 cells showed significant inhibition of proliferation in vitro and reduction of tumor growth in vivo. Furthermore, E-cadherin expression increased in LIV-1 siRNA expressing Hep-G2. These findings indicated that LIV-1 may induce the EMT in HCC cells.

Spatial control of direct chemical vapor deposition of graphene on silicon dioxide by directional copper dewetting

NARCIS (Netherlands)

van den Beld, Wesley Theodorus Eduardus; van den Berg, Albert; Eijkel, Jan C.T.

2016-01-01

In this paper we present a method for the spatial control of direct graphene synthesis onto silicon dioxide by controlled dewetting. The dewetting process is controlled through a combination of using a grooved substrate and conducting copper deposition at an angle. The substrate is then treated

Optimization of controllability and robustness of complex networks by edge directionality

Science.gov (United States)

Liang, Man; Jin, Suoqin; Wang, Dingjie; Zou, Xiufen

2016-09-01

Recently, controllability of complex networks has attracted enormous attention in various fields of science and engineering. How to optimize structural controllability has also become a significant issue. Previous studies have shown that an appropriate directional assignment can improve structural controllability; however, the evolution of the structural controllability of complex networks under attacks and cascading has always been ignored. To address this problem, this study proposes a new edge orientation method (NEOM) based on residual degree that changes the link direction while conserving topology and directionality. By comparing the results with those of previous methods in two random graph models and several realistic networks, our proposed approach is demonstrated to be an effective and competitive method for improving the structural controllability of complex networks. Moreover, numerical simulations show that our method is near-optimal in optimizing structural controllability. Strikingly, compared to the original network, our method maintains the structural controllability of the network under attacks and cascading, indicating that the NEOM can also enhance the robustness of controllability of networks. These results alter the view of the nature of controllability in complex networks, change the understanding of structural controllability and affect the design of network models to control such networks.

Platelets Regulate the Migration of Keratinocytes via Podoplanin/CLEC-2 Signaling during Cutaneous Wound Healing in Mice.

Science.gov (United States)

Asai, Jun; Hirakawa, Satoshi; Sakabe, Jun-ichi; Kishida, Tsunao; Wada, Makoto; Nakamura, Naomi; Takenaka, Hideya; Mazda, Osam; Urano, Tetsumei; Suzuki-Inoue, Katsue; Tokura, Yoshiki; Katoh, Norito

2016-01-01

Podoplanin is an endogenous ligand for C-type lectin-like receptor 2 (CLEC-2), which is expressed on platelets. Recent evidence indicates that this specific marker of lymphatic endothelial cells is also expressed by keratinocytes at the edge of wounds. However, whether podoplanin or platelets play a role in keratinocyte activity during wound healing remains unknown. We evaluated the effect of podoplanin expression levels on keratinocyte motility using cultured primary normal human epidermal keratinocytes (NHEKs). Down-regulation of podoplanin in NHEKs via transfection with podoplanin siRNA inhibited their migration, indicating that podoplanin plays a mandatory role in this process. In addition, down-regulation of podoplanin was correlated with up-regulation of E-cadherin, suggesting that podoplanin-mediated stimulation of keratinocyte migration is associated with a loss of E-cadherin. Both the addition of platelets and treatment with CLEC-2 inhibited the migration of NHEKs. The down-regulation of RhoA activity and the up-regulation of E-cadherin in keratinocytes were also induced by CLEC-2. In conclusion, these results suggest that podoplanin/CLEC-2 signaling regulates keratinocyte migration via modulating E-cadherin expression through RhoA signaling. Altering the regulation of keratinocyte migration by podoplanin might be a novel therapeutic approach to improve wound healing. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

A Review on Direct Power Control for Applications to Grid Connected PWM Converters

Directory of Open Access Journals (Sweden)

T. A. Trivedi

2015-08-01

Full Text Available The Direct Power Control strategy has become popular as an alternative to the conventional vector oriented control strategy for grid connected PWM converters. In this paper, Direct Power Control as applied to various applications of grid connected converters is reviewed. The Direct Power Control for PWM rectifiers, Grid Connected DC/AC inverters applications such as renewable energy sources interface, Active Power Filters, Doubly Fed Induction Generators and AC-DC-AC converters are discussed. Control strategies such as Look-Up table based control, predictive control, Virtual Flux DPC, Model based DPC and DPC-Space Vector Modulation are critically reviewed. The effects of various key parameters such as selection of switching vector, sampling time, hysteresis band and grid interfacing on performance of direct power controlled converters are presented.

Development of the 'JFT-2' tokamak plasma position control system

International Nuclear Information System (INIS)

Fujisawa, Noboru; Matsuzaki, Yoshimi; Suzuki, Norio; Murai, Katsuji; Suzuki, Satoshi.

1980-01-01

Digital control technique was applied to control the plasma position in the JFT-2 tokamak experiment device. The detail of the JFT-2 is described elsewhere. The plasma position control system consists of a Hitachi control computer, HIDIC 80, and a Hitachi micro-computer, HIDIC 08E. The plasma position is detected by the position control computer, and compared with a preset value. Then, a reference signal is supplied to the micro-computer controlling power source, and the phase control of the thyristor controlling power source is performed. Since the behavior of plasma is very fast, the fast control is required. The control of the thyristor controlling power source is made by direct digital control (DDC). The main component of the hardware of the present system is the micro-computer HIDIC 08E. The software is the direct task system without the operating system (OS). The results of experiments showed that the feedback control of the system worked well. (Kato, T.)

Composite bonded magnets with controlled anisotropy directions prepared by viscous deformation technique

International Nuclear Information System (INIS)

Yamashita, Fumitoshi; Kawamura, Kiyomi; Okada, Yukihiro; Murakami, Hiroshi; Ogushi, Masaki; Nakano, Masaki; Fukunaga, Hirotoshi

2007-01-01

When a radially anisotropic rare earth bonded magnet for a rotor with a high (BH) max value is magnetized multi-polarly, its flux distributes rectangularly and increases a cogging torque. In order to overcome this difficulty, we newly developed highly dense Sm 2 Fe 17 N 3 and Nd 2 Fe 14 B-based composite bonded magnets with continuously controlled anisotropy directions by using a viscous deformation technique

The invasive phenotype of placenta accreta extravillous trophoblasts associates with loss of E-cadherin.

Science.gov (United States)

Duzyj, C M; Buhimschi, I A; Motawea, H; Laky, C A; Cozzini, G; Zhao, G; Funai, E F; Buhimschi, C S

2015-06-01

Epithelial-to-mesenchymal transition (EMT) is a process of molecular and phenotypic epithelial cell alteration promoting invasiveness. Loss of E-cadherin (E-CAD), a transmembrane protein involved in cell adhesion, is a marker of EMT. Proteolysis into N- and C-terminus fragments by ADAM10 and presenilin-1 (PSEN-1) generates soluble (sE-CAD) and transcriptionally active forms. We studied the protein expression patterns of E-CAD in the serum and placenta of women with histologically-confirmed over-invasive placentation. The patterns of expression and levels of sE-CAD were analyzed by Western blot, immunoassay, and immunoprecipitation. Tissue immunostaining for E-CAD, cytokeratin-7 (epithelial marker), vimentin (mesenchymal marker), ADAM10, PSEN-1 and β-catenin expression were investigated in parallel. N-terminus cleaved 80 kDa sE-CAD fragments were present in serum of pregnant women with gestational age regulation of the circulatory levels. Women with advanced trophoblast invasion did not display circulatory levels of sE-CAD different from those of women with normal placentation. Histologically, extravillous trophoblasts (EVT) closer to the placental-myometrial interface demonstrated less E-CAD staining than those found deeper in the myometrium. These cells expressed both vimentin and cytokeratin, an additional feature of EMT. EVT of placentas with advanced invasion displayed intracellular E-CAD C-terminus immunoreactivity predominating over that of the extracellular N-terminus, a pattern consistent with preferential PSEN-1 processing. Local processing of E-CAD may be an important molecular mechanism controlling the invasive phenotype of accreta EVT. Copyright © 2015 Elsevier Ltd. All rights reserved.

Wheels Optimization and Vision Control of Omni-directional Mobile Microrobot

Directory of Open Access Journals (Sweden)

Jianghao Li

2008-11-01

Full Text Available This paper presents a millimeters scale omni-directional mobile microrobot with special dual-wheel structure. The microrobot was actuated by three electromagnetic micromotors of 2mm diameter. Dynamic analysis of translational and steering movements presented the relationship between the sizes of the dual-wheel structure and the output torque of the micromotor. Genetic algorithm (GA was employed to optimize the dualwheel's sizes for reducing the unnecessary torque consumption and improving the driving ability of the microrobot. A computer vision system contained two sets of feedback control is devised for the microrobot. Torque self-balance and current-limiting control approach are presented to ensure the accuracy of step movement. Experiment results demonstrate the feasibility of these concepts.

Enhancement of direct sulfation of limestone by Na{sub 2}CO{sub 3} addition

Energy Technology Data Exchange (ETDEWEB)

Chuanmin Chen; Ye Zhuang; Chunbo Wang [North China Electric Power University, Baoding (China). School of Environmental Science & Engineering

2009-07-15

For an oxy-fuel circulating fluidized bed combustion system, the limestone calcination is normally prevented due to excessive CO{sub 2} partial pressures and the limestone is subject to a direct sulfation reaction. The enhancement of the direct sulfation of limestone by Na{sub 2}CO{sub 3} was investigated under high CO{sub 2} partial pressure in a thermogravimetric apparatus (TGA) and scanning electron microscope (SEM) analysis method. A commercial limestone with a mean size of 18.8 {mu}m was used. Experimental results indicate that the incorporation of Na{sup +} ions in solid product CaSO{sub 4} lattice structures results in formation of more extrinsic point defects in the crystal lattices of CaSO{sub 4} and a significantly increased solid-state diffusivity/mobility in the solid product. So the direct sulfation of Na{sub 2}CO{sub 3}-doped limestone shows higher rate and higher degree of conversion in the later stage of sulfation, in comparison with the direct sulfation of original limestone. The reaction changes from diffusional control to chemical reaction control in the presence of Na{sub 2}CO{sub 3} because of the effect of foreign ions on accelerating the solid-state diffusion. 33 refs., 7 figs., 2 tabs.

Amino acid sequence of bovine muzzle epithelial desmocollin derived from cloned cDNA: a novel subtype of desmosomal cadherins.

Science.gov (United States)

Koch, P J; Goldschmidt, M D; Walsh, M J; Zimbelmann, R; Schmelz, M; Franke, W W

1991-05-01

Desmosomes are cell-type-specific intercellular junctions found in epithelium, myocardium and certain other tissues. They consist of assemblies of molecules involved in the adhesion of specific cell types and in the anchorage of cell-type-specific cytoskeletal elements, the intermediate-size filaments, to the plasma membrane. To explore the individual desmosomal components and their functions we have isolated DNA clones encoding the desmosomal glycoprotein, desmocollin, using antibodies and a cDNA expression library from bovine muzzle epithelium. The cDNA-deduced amino-acid sequence of desmocollin (presently we cannot decide to which of the two desmocollins, DC I or DC II, this clone relates) defines a polypeptide with a calculated molecular weight of 85,000, with a single candidate sequence of 24 amino acids sufficiently long for a transmembrane arrangement, and an extracellular aminoterminal portion of 561 amino acid residues, compared to a cytoplasmic part of only 176 amino acids. Amino acid sequence comparisons have revealed that desmocollin is highly homologous to members of the cadherin family of cell adhesion molecules, including the previously sequenced desmoglein, another desmosome-specific cadherin. Using riboprobes derived from cDNAs for Northern-blot analyses, we have identified an mRNA of approximately 6 kb in stratified epithelia such as muzzle epithelium and tongue mucosa but not in two epithelial cell culture lines containing desmosomes and desmoplakins. The difference may indicate drastic differences in mRNA concentration or the existence of cell-type-specific desmocollin subforms. The molecular topology of desmocollin(s) is discussed in relation to possible functions of the individual molecular domains.

Nanoscale Engineering in VO2 Nanowires via Direct Electron Writing Process.

Science.gov (United States)

Zhang, Zhenhua; Guo, Hua; Ding, Wenqiang; Zhang, Bin; Lu, Yue; Ke, Xiaoxing; Liu, Weiwei; Chen, Furong; Sui, Manling

2017-02-08

Controlling phase transition in functional materials at nanoscale is not only of broad scientific interest but also important for practical applications in the fields of renewable energy, information storage, transducer, sensor, and so forth. As a model functional material, vanadium dioxide (VO 2 ) has its metal-insulator transition (MIT) usually at a sharp temperature around 68 °C. Here, we report a focused electron beam can directly lower down the transition temperature of a nanoarea to room temperature without prepatterning the VO 2 . This novel process is called radiolysis-assisted MIT (R-MIT). The electron beam irradiation fabricates a unique gradual MIT zone to several times of the beam size in which the temperature-dependent phase transition is achieved in an extended temperature range. The gradual transformation zone offers to precisely control the ratio of metal/insulator phases. This direct electron writing technique can open up an opportunity to precisely engineer nanodomains of diversified electronic properties in functional material-based devices.

The C-terminal domain of Rac1 contains two motifs that control targeting and signaling specificity

NARCIS (Netherlands)

van Hennik, Paula B.; ten Klooster, Jean Paul; Halstead, Jon R.; Voermans, Carlijn; Anthony, Eloise C.; Divecha, Nullin; Hordijk, Peter L.

2003-01-01

Rho-like GTPases control a wide range of cellular functions such as integrin- and cadherin-mediated adhesion, cell motility, and gene expression. The hypervariable C-terminal domain of these GTPases has been implicated in membrane association and effector binding. We found that cell-permeable

N-(4-Hydroxyphenyl) retinamide potentiated paclitaxel for cell cycle arrest and apoptosis in glioblastoma C6 and RG2 cells

OpenAIRE

Janardhanan, Rajiv; Butler, Jonathan T.; Banik, Naren L.; Ray, Swapan K.

2009-01-01

Glioblastoma grows aggressively due to its ability to maintain abnormally high potentials for cell proliferation. The present study examines the synergistic actions of N-(4-hdroxyphenyl) retinamide (4-HPR) and paclitaxel (PTX) to control the growth of rat glioblastoma C6 and RG2 cell lines. 4-HPR induced astrocytic differentiation was accompanied by increased expression of the tight junction protein e-cadherin and sustained down regulation of Id2 (member of inhibitor of differentiation family...

Enhancement of direct sulfation of limestone by Na{sub 2}CO{sub 3} addition

Energy Technology Data Exchange (ETDEWEB)

Chen, Chuanmin [School of Environmental Science and Engineering, North China Electric Power University, Baoding 071003, Hebei Province (China); Zhuang, Ye [Energy and Environmental Research Center, University of North Dakota, 15 North 23rd Street, Grand Forks, ND 58203 (United States); Wang, Chunbo [Department of Power engineering, North China Electric Power University, Baoding 071003, Hebei Province (China)

2009-07-15

For an oxy-fuel circulating fluidized bed combustion system, the limestone calcination is normally prevented due to excessive CO{sub 2} partial pressures and the limestone is subject to a direct sulfation reaction. The enhancement of the direct sulfation of limestone by Na{sub 2}CO{sub 3} was investigated under high CO{sub 2} partial pressure in a thermogravimetric apparatus (TGA) and scanning electron microscope (SEM) analysis method. A commercial limestone with a mean size of 18.8 {mu}m was used. Experimental results indicate that the incorporation of Na{sup +} ions in solid product CaSO{sub 4} lattice structures results in formation of more extrinsic point defects in the crystal lattices of CaSO{sub 4} and a significantly increased solid-state diffusivity/mobility in the solid product. So the direct sulfation of Na{sub 2}CO{sub 3}-doped limestone shows higher rate and higher degree of conversion in the later stage of sulfation, in comparison with the direct sulfation of original limestone. The reaction changes from diffusional control to chemical reaction control in the presence of Na{sub 2}CO{sub 3} because of the effect of foreign ions on accelerating the solid-state diffusion. (author)

Study of Direct-Contact HfO2/Si Interfaces

Directory of Open Access Journals (Sweden)

Noriyuki Miyata

2012-03-01

Full Text Available Controlling monolayer Si oxide at the HfO2/Si interface is a challenging issue in scaling the equivalent oxide thickness of HfO2/Si gate stack structures. A concept that the author proposes to control the Si oxide interface by using ultra-high vacuum electron-beam HfO2 deposition is described in this review paper, which enables the so-called direct-contact HfO2/Si structures to be prepared. The electrical characteristics of the HfO2/Si metal-oxide-semiconductor capacitors are reviewed, which suggest a sufficiently low interface state density for the operation of metal-oxide-semiconductor field-effect-transistors (MOSFETs but reveal the formation of an unexpected strong interface dipole. Kelvin probe measurements of the HfO2/Si structures provide obvious evidence for the formation of dipoles at the HfO2/Si interfaces. The author proposes that one-monolayer Si-O bonds at the HfO2/Si interface naturally lead to a large potential difference, mainly due to the large dielectric constant of the HfO2. Dipole scattering is demonstrated to not be a major concern in the channel mobility of MOSFETs.

Ecodesign Directive version 2.0

DEFF Research Database (Denmark)

This present report reports on the main findings of the project Ecodesign Directive version 2.0 - from Energy Efficiency to Resource Efficiency. The project is financed by the Danish Environmental Protection Agency and ran from December 2012 to June 2014.......This present report reports on the main findings of the project Ecodesign Directive version 2.0 - from Energy Efficiency to Resource Efficiency. The project is financed by the Danish Environmental Protection Agency and ran from December 2012 to June 2014....

2-regularity and 2-normality conditions for systems with impulsive controls

Directory of Open Access Journals (Sweden)

Pavlova Natal'ya

2007-01-01

Full Text Available In this paper a controlled system with impulsive controls in the neighborhood of an abnormal point is investigated. The set of pairs (u,μ is considered as a class of admissible controls, where u is a measurable essentially bounded function and μ is a finite-dimensional Borel measure, such that for any Borel set B, μ(B is a subset of the given convex closed pointed cone. In this article the concepts of 2-regularity and 2-normality for the abstract mapping Ф, operating from the given Banach space into a finite-dimensional space, are introduced. The concepts of 2-regularity and 2-normality play a great role in the course of derivation of the first and the second order necessary conditions for the optimal control problem, consisting of the minimization of a certain functional on the set of the admissible processes. These concepts are also important for obtaining the sufficient conditions for the local controllability of the nonlinear systems. The convenient criterion for 2-regularity along the prescribed direction and necessary conditions for 2-normality of systems, linear in control, are introduced in this article as well.

Wheels Optimization and Vision Control of Omni-directional Mobile Microrobot

Directory of Open Access Journals (Sweden)

Jianghao Li

2008-06-01

Full Text Available This paper presents a millimeters scale omni-directional mobile microrobot with special dual-wheel structure. The microrobot was actuated by three electromagnetic micromotors of 2mm diameter. Dynamic analysis of translational and steering movements presented the relationship between the sizes of the dual-wheel structure and the output torque of the micromotor. Genetic algorithm (GA was employed to optimize the dual-wheel's sizes for reducing the unnecessary torque consumption and improving the driving ability of the microrobot. A computer vision system contained two sets of feedback control is devised for the microrobot. Torque self-balance and current-limiting control approach are presented to ensure the accuracy of step movement. Experiment results demonstrate the feasibility of these concepts.

[Pseudolaric acid B induces G2/M arrest and inhibits invasion and migration in HepG2 hepatoma cells].

Science.gov (United States)

Li, Shuai; Guo, Lianyi

2018-01-01

Objective To investigate the mechanisms of pseudolaric acid B (PAB) blocks cell cycle and inhibits invasion and migration in human hepatoma HepG2 cells. Methods The proliferation effect of PAB on HepG2 cells was evaluated by MTT assay. The effect of PAB on the cell cycle of HepG2 cells was analyzed by flow cytometry. Immunofluorescence cytochemical staining was applied to observe the effect of PAB on the α-tubulin polymerization and expression in HepG2 cells. Transwell TM chamber invasion assay and wound healing assay were performed to detect the influence of PAB on the migration and invasion ability of HepG2 cells. Western blotting was used to determine the expressions of α-tubulin, E-cadherin and MMP-9 in HepG2 cells after treated with PAB. Results PAB inhibited the proliferation of HepG2 cells in a dose-dependent manner and blocked the cell cycle in G2/M phase. PAB significantly changed the polymerization and decreased the expression of α-tubulin. The capacities of invasion and migration of HepG2 cells treated by PAB were significantly depressed. The protein levels of α-tubulin and MMP-9 decreased while the E-cadherin protein level increased. Conclusion PAB can inhibits the proliferation of HepG2 cells by down-regulating the expression of α-tubulin and influencing its polymerization, arresting HepG2 cells in G2/M phase. Meanwhile, PAB also can inhibit the invasion and migration of HepG2 cells by lowering cytoskeleton α-tubulin and MMP-9, and increasing E-cadherin.

The N-Myc down regulated Gene1 (NDRG1) Is a Rab4a effector involved in vesicular recycling of E-cadherin.

Science.gov (United States)

Kachhap, Sushant K; Faith, Dennis; Qian, David Z; Shabbeer, Shabana; Galloway, Nathan L; Pili, Roberto; Denmeade, Samuel R; DeMarzo, Angelo M; Carducci, Michael A

2007-09-05

Cell to cell adhesion is mediated by adhesion molecules present on the cell surface. Downregulation of molecules that form the adhesion complex is a characteristic of metastatic cancer cells. Downregulation of the N-myc down regulated gene1 (NDRG1) increases prostate and breast metastasis. The exact function of NDRG1 is not known. Here by using live cell confocal microscopy and in vitro reconstitution, we report that NDRG1 is involved in recycling the adhesion molecule E-cadherin thereby stabilizing it. Evidence is provided that NDRG1 recruits on recycling endosomes in the Trans Golgi network by binding to phosphotidylinositol 4-phosphate and interacts with membrane bound Rab4aGTPase. NDRG1 specifically interacts with constitutively active Rab4aQ67L mutant protein and not with GDP-bound Rab4aS22N mutant proving NDRG1 as a novel Rab4a effector. Transferrin recycling experiments reveals NDRG1 colocalizes with transferrin during the recycling phase. NDRG1 alters the kinetics of transferrin recycling in cells. NDRG1 knockdown cells show a delay in recycling transferrin, conversely NDRG1 overexpressing cells reveal an increase in rate of transferrin recycling. This novel finding of NDRG1 as a recycling protein involved with recycling of E-cadherin will aid in understanding NDRG1 role as a metastasis suppressor protein.

The N-Myc down regulated Gene1 (NDRG1 Is a Rab4a effector involved in vesicular recycling of E-cadherin.

Directory of Open Access Journals (Sweden)

Sushant K Kachhap

2007-09-01

Full Text Available Cell to cell adhesion is mediated by adhesion molecules present on the cell surface. Downregulation of molecules that form the adhesion complex is a characteristic of metastatic cancer cells. Downregulation of the N-myc down regulated gene1 (NDRG1 increases prostate and breast metastasis. The exact function of NDRG1 is not known. Here by using live cell confocal microscopy and in vitro reconstitution, we report that NDRG1 is involved in recycling the adhesion molecule E-cadherin thereby stabilizing it. Evidence is provided that NDRG1 recruits on recycling endosomes in the Trans Golgi network by binding to phosphotidylinositol 4-phosphate and interacts with membrane bound Rab4aGTPase. NDRG1 specifically interacts with constitutively active Rab4aQ67L mutant protein and not with GDP-bound Rab4aS22N mutant proving NDRG1 as a novel Rab4a effector. Transferrin recycling experiments reveals NDRG1 colocalizes with transferrin during the recycling phase. NDRG1 alters the kinetics of transferrin recycling in cells. NDRG1 knockdown cells show a delay in recycling transferrin, conversely NDRG1 overexpressing cells reveal an increase in rate of transferrin recycling. This novel finding of NDRG1 as a recycling protein involved with recycling of E-cadherin will aid in understanding NDRG1 role as a metastasis suppressor protein.

Controller Design for Direct Torque Controlled Space Vector Modulated (DTC-SVM) Induction Motor Drives

DEFF Research Database (Denmark)

Zelechowski, M.; Kazmierkowski, M.P.; Blaabjerg, Frede

2005-01-01

In this paper two different methods of PI controllers for direct torque controlled-space vector modulated induction motor drives have been studied. The first one is simple method based only on symmetric optimum criterion. The second approach takes into account the full model of induction motor in...

Loss of the polycomb protein Mel-18 enhances the epithelial-mesenchymal transition by ZEB1 and ZEB2 expression through the downregulation of miR-205 in breast cancer.

Science.gov (United States)

Lee, J-Y; Park, M K; Park, J-H; Lee, H J; Shin, D H; Kang, Y; Lee, C H; Kong, G

2014-03-06

The epithelial-mesenchymal transition (EMT) is the pivotal mechanism underlying the initiation of cancer invasion and metastasis. Although Mel-18 has been implicated in several biological processes in cancer, its function in the EMT of human cancers has not yet been studied. Here, we demonstrate that Mel-18 negatively regulates the EMT by epigenetically modulating miR-205. We identified miR-205 as a novel target of Mel-18 using a microRNA microarray analysis and found that Mel-18 increased miR-205 transcription by the inhibition of DNA methyltransferase-mediated DNA methylation of the miR-205 promoter, thereby downregulating its target genes, ZEB1 and ZEB2. Furthermore, the loss of Mel-18 promoted ZEB1- and ZEB2-mediated downregulation of E-cadherin transcription and also enhanced the expression of mesenchymal markers, leading to increased migration and invasion in MCF-7 cells. In MDA-MB-231 cells, Mel-18 overexpression restored E-cadherin expression, resulting in reduced migration and invasion. These effects were reversed by miR-205 overexpression or inhibition. A tumor xenograft with Mel-18 knockdown MCF-7 cells consistently showed increased ZEB1 and ZEB2 expression and decreased E-cadherin expression. Taken together, these results suggest that Mel-18 functions as a tumor suppressor by its novel negative control of the EMT, achieved through regulating the expression of miR-205 and its target genes, ZEB1 and ZEB2.

An Intuitive Definition of Demand Flexibility in Direct Load Control

DEFF Research Database (Denmark)

Tahersima, Fatemeh; Madsen, Per Printz; Andersen, Palle

2013-01-01

Two control approaches: direct and indirect control of demand side energy management in a smart grid are studied. Indirect control of energy demands is based on economic incentives. In this approach, consumers will shift their energy consumption with the benefit of a cut down in the electricity b...

Direct Torque Control of Matrix Converter Fed Induction Motor Drive

Directory of Open Access Journals (Sweden)

JAGADEESAN Karpagam

2011-10-01

Full Text Available This paper presents the Direct TorqueControl (DTC of induction motor drive using matrixconverters. DTC is a high performance motor controlscheme with fast torque and flux responses. However,the main disadvantage of conventional DTC iselectromagnetic torque ripple. In this paper, directtorque control for Induction Motors using MatrixConverters is analysed and points out the problem ofthe electromagnetic torque ripple which is one of themost important drawbacks of the Direct TorqueControl. Besides, the matrix converter is a single-stageac-ac power conversion device without dc-link energystorage elements. Matrix converter (MC may becomea good alternative to voltage-source inverter (VSI.This work combines the advantages of the matrixconverter with those of the DTC technique, generatingthe required voltage vectors under unity input powerfactor operation. Simulation results demonstrates theeffectiveness of the torque control.

Induction of cell scattering by expression of beta1 integrins in beta1-deficient epithelial cells requires activation of members of the rho family of GTPases and downregulation of cadherin and catenin function

DEFF Research Database (Denmark)

Gimond, C; van Der Flier, A; van Delft, S

1999-01-01

different beta1-null cell lines, epithelial GE11 and fibroblast-like GD25 cells. Expression of beta1A or the cytoplasmic splice variant beta1D, induced the disruption of intercellular adherens junctions and cell scattering in both GE11 and GD25 cells. In GE11 cells, the morphological change correlated...... for a complete morphological transition towards the spindle-shaped fibroblast-like phenotype. The expression of an interleukin-2 receptor (IL2R)-beta1A chimera and its incorporation into focal adhesions also induced the disruption of cadherin-based adhesions and the reorganization of ECM-cell contacts...

Effects of gut-directed hypnotherapy on IBS in different clinical settings-results from two randomized, controlled trials.

Science.gov (United States)

Lindfors, Perjohan; Unge, Peter; Arvidsson, Patrik; Nyhlin, Henry; Björnsson, Einar; Abrahamsson, Hasse; Simrén, Magnus

2012-02-01

Gut-directed hypnotherapy has been found to be effective in irritable bowel syndrome (IBS). However, randomized, controlled studies are rare and few have been performed outside highly specialized research centers. The objective of this study was to study the effect of gut-directed hypnotherapy in IBS in different clinical settings outside the traditional research units. The study population included IBS patients refractory to standard management. In study 1, patients were randomized to receive gut-directed hypnotherapy (12 sessions, 1 h/week) in psychology private practices or supportive therapy, whereas patients were randomized to receive gut-directed hypnotherapy in a small county hospital or to serve as waiting list controls in study 2. Gastrointestinal symptom severity and quality of life were evaluated at baseline, at 3 months follow-up and after 1 year. We randomized 138 IBS patients refractory to standard management, 90 in study 1 and 48 in study 2. In both the studies, IBS-related symptoms were improved at 3 months in the gut-directed hypnotherapy groups (Phypnotherapy group than in the control group (Phypnotherapy is an effective treatment alternative for patients with refractory IBS, but the effectiveness is lower when the therapy is given outside the highly specialized research centers.

Analysis and control of excitation, field weakening and stability in direct torque controlled electrically excited synchronous motor drives

Energy Technology Data Exchange (ETDEWEB)

Pyrhoenen, O

1999-12-31

Direct torque control (DTC) is a new control method for rotating field electrical machines. DTC controls directly the motor stator flux linkage with the stator voltage, and no stator current controllers are used. With the DTC method very good torque dynamics can be achieved. Until now, DTC has been applied to asynchronous motor drives. The purpose of this work is to analyse the applicability of DTC to electrically excited synchronous motor drives. Compared with asynchronous motor drives, electrically excited synchronous motor drives require an additional control for the rotor field current. The field current control is called excitation control in this study. The dependence of the static and dynamic performance of DTC synchronous motor drives on the excitation control has been analysed and a straightforward excitation control method has been developed and tested. In the field weakening range the stator flux linkage modulus must be reduced in order to keep the electro motive force of the synchronous motor smaller than the stator voltage and in order to maintain a sufficient voltage reserve. The dynamic performance of the DTC synchronous motor drive depends on the stator flux linkage modulus. Another important factor for the dynamic performance in the field weakening range is the excitation control. The field weakening analysis considers both dependencies. A modified excitation control method, which maximises the dynamic performance in the field weakening range, has been developed. In synchronous motor drives the load angle must be kept in a stabile working area in order to avoid loss of synchronism. The traditional vector control methods allow to adjust the load angle of the synchronous motor directly by the stator current control. In the DTC synchronous motor drive the load angle is not a directly controllable variable, but it is formed freely according to the motor`s electromagnetic state and load. The load angle can be limited indirectly by limiting the torque

Analysis and control of excitation, field weakening and stability in direct torque controlled electrically excited synchronous motor drives

Energy Technology Data Exchange (ETDEWEB)

Pyrhoenen, O.

1998-12-31

Direct torque control (DTC) is a new control method for rotating field electrical machines. DTC controls directly the motor stator flux linkage with the stator voltage, and no stator current controllers are used. With the DTC method very good torque dynamics can be achieved. Until now, DTC has been applied to asynchronous motor drives. The purpose of this work is to analyse the applicability of DTC to electrically excited synchronous motor drives. Compared with asynchronous motor drives, electrically excited synchronous motor drives require an additional control for the rotor field current. The field current control is called excitation control in this study. The dependence of the static and dynamic performance of DTC synchronous motor drives on the excitation control has been analysed and a straightforward excitation control method has been developed and tested. In the field weakening range the stator flux linkage modulus must be reduced in order to keep the electro motive force of the synchronous motor smaller than the stator voltage and in order to maintain a sufficient voltage reserve. The dynamic performance of the DTC synchronous motor drive depends on the stator flux linkage modulus. Another important factor for the dynamic performance in the field weakening range is the excitation control. The field weakening analysis considers both dependencies. A modified excitation control method, which maximises the dynamic performance in the field weakening range, has been developed. In synchronous motor drives the load angle must be kept in a stabile working area in order to avoid loss of synchronism. The traditional vector control methods allow to adjust the load angle of the synchronous motor directly by the stator current control. In the DTC synchronous motor drive the load angle is not a directly controllable variable, but it is formed freely according to the motor`s electromagnetic state and load. The load angle can be limited indirectly by limiting the torque

Shape-controlled synthesis of nanocarbons through direct conversion of carbon dioxide

Science.gov (United States)

Zhang, Haitao; Zhang, Xiong; Sun, Xianzhong; Ma, Yanwei

2013-12-01

Morphology control of carbon-based nanomaterials (nanocarbons) is critical to practical applications because their physical and chemical properties are highly shape-dependent. The discovery of novel shaped nanocarbons stimulates new development in carbon science and technology. Based on direct reaction of CO2 with Mg metal, we achieved controlled synthesis of several different types of nanocarbons including mesoporous graphene, carbon nanotubes, and hollow carbon nanoboxes. The last one, to our knowledge, has not been previously reported to this date. The method described here allows effective control of the shape and dimensions of nanocarbons through manipulation of reaction temperature. The formation mechanism of nanocarbons is proposed. As a proof of concept, the synthesized nanocarbons are used for electrodes in symmetrical supercapacitors, which exhibit high capacitance and good cycling stability. The reported protocols are instructive to production of nanocarbons with controlled shape and dimensions which are much desirable for many practical applications.

A Fault Tolerant Direct Control Allocation Scheme with Integral Sliding Modes

Directory of Open Access Journals (Sweden)

Hamayun Mirza Tariq

2015-03-01

Full Text Available In this paper, integral sliding mode control ideas are combined with direct control allocation in order to create a fault tolerant control scheme. Traditional integral sliding mode control can directly handle actuator faults; however, it cannot do so with actuator failures. Therefore, a mechanism needs to be adopted to distribute the control effort amongst the remaining functioning actuators in cases of faults or failures, so that an acceptable level of closed-loop performance can be retained. This paper considers the possibility of introducing fault tolerance even if fault or failure information is not provided to the control strategy. To demonstrate the efficacy of the proposed scheme, a high fidelity nonlinear model of a large civil aircraft is considered in the simulations in the presence of wind, gusts and sensor noise.

IPMSM Motion-Sensorless Direct Torque and Flux Control

DEFF Research Database (Denmark)

Pitict, Christian Ilie; Andreescu, Gheorghe-Daniel; Blaabjerg, Frede

2005-01-01

The paper presents a rather comprehensive implementation of a wide speed motion-sensorless control of IPMSM drives via direct torque and flux control (DTFC) with space vector modulation (SVM). Signal injection with only one D-module vector filter and phase-locked loop (PLL) observer is used at low...... provides for a smooth current waveform even at 1 rpm. The paper demonstrates through ample experiments a 1750 rpm 1 1 rpm speed range full-loaded with sensorless DTFC-SVM....

Direct imaging electron microscopy (EM) methods in modern structural biology: overview and comparison with X-ray crystallography and single-particle cryo-EM reconstruction in the studies of large macromolecules.

Science.gov (United States)

Miyaguchi, Katsuyuki

2014-10-01

Determining the structure of macromolecules is important for understanding their function. The fine structure of large macromolecules is currently studied primarily by X-ray crystallography and single-particle cryo-electron microscopy (EM) reconstruction. Before the development of these techniques, macromolecular structure was often examined by negative-staining, rotary-shadowing and freeze-etching EM, which are categorised here as 'direct imaging EM methods'. In this review, the results are summarised by each of the above techniques and compared with respect to four macromolecules: the ryanodine receptor, cadherin, rhodopsin and the ribosome-translocon complex (RTC). The results of structural analysis of the ryanodine receptor and cadherin are consistent between each technique. The results obtained for rhodopsin vary to some extent within each technique and between the different techniques. Finally, the results for RTC are inconsistent between direct imaging EM and other analytical techniques, especially with respect to the space within RTC, the reasons for which are discussed. Then, the role of direct imaging EM methods in modern structural biology is discussed. Direct imaging methods should support and verify the results obtained by other analytical methods capable of solving three-dimensional molecular architecture, and they should still be used as a primary tool for studying macromolecule structure in vivo. © 2014 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.

Direct write printing of three-dimensional ZrO2 biological scaffolds

International Nuclear Information System (INIS)

Li, Ya-yun; Li, Long-tu; Li, Bo

2015-01-01

Graphical abstract: Three-dimensional (3D) zirconium dioxide (ZrO 2 ) scaffolds have been fabricated for biological engineering by direct write printing method. The water-based ZrO 2 ink with a solid content fraction of 70 wt% was deposited through a fine nozzle on the substrate by a layer-by-layer sequence to produce the 3D microperiodic structures. Under a microscope, the proliferation of HCT116 cells can be observed around the 3D ZrO 2 scaffolds. 3D porous internal architecture is beneficial for cell growth by providing more locations for cell attachment and proliferation. The largest value of compressive strength reached 10 MPa, which is more than that of the hydroxyapatite (HAp) scaffold. The ability of printing 3D scaffolds with the high precise control of their internal architecture is the unique characteristics performed by the direct write technique, which will provide potential application of biomaterials and tissue engineering scaffolds. (a) Top view of the sintered 3D woodpile ZrO 2 scaffold; (b) top view of the sintered 3D cylindrical ZrO 2 scaffold. - Highlights: • 3D cylindrical and woodpile ZrO 2 scaffolds were fabricated by direct write printing method. • The compressive strength of the sample with porosity about 63% was 8 MPa. • The compressive strength of the porosity 55% sample was 10 MPa. • 3D porous ZrO 2 scaffolds with interconnected architecture are beneficial for cell attachment and proliferation. - Abstract: Three-dimensional (3D) zirconium dioxide (ZrO 2 ) scaffolds have been fabricated for biological engineering by direct write printing method. The water-based ZrO 2 ink with a solid content fraction of 70 wt% was deposited through a fine nozzle on the substrate by a layer-by-layer sequence to produce the 3D microperiodic structures. The preparation and the rheological behavior of this ink, as well as the principles of the direct write printing process were investigated systematically. Sintered at 1250 °C for 4 h was the optimal

Direct battery-driven solar LED lighting using constant-power control

KAUST Repository

Huang, Bin-Juine; Chen, Chun-Wei; Hsu, Po-Chien; Tseng, Wei-Min; Wu, Min-Sheng

2012-01-01

A direct battery-driven LED lighting technique using constant-power control is proposed in the present study. A system dynamics model of LED luminaire was derived and used in the design of the feedback constant-power control system. The test result

Hexavalent chromium at low concentration alters Sertoli cell barrier and connexin 43 gap junction but not claudin-11 and N-cadherin in the rat seminiferous tubule culture model

Energy Technology Data Exchange (ETDEWEB)

Carette, Diane [INSERM U 1065, Team 5 “Physiopathology of Germ Cell Control: Genomic and Non Genomic Mechanisms” C3M, University of Nice Sophia Antipolis, Nice (France); UMR S775, University Paris Descartes, 45 rue des Saints Pères, 75006, Paris (France); Perrard, Marie-Hélène, E-mail: marie-helene.durand@ens-lyon.fr [Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Lyon I, CNRS, INRA, Ecole Normale Supérieure de Lyon, Lyon (France); Prisant, Nadia [University of Versailles/St Quentin-en-Yvelines (France); UMR S775, University Paris Descartes, 45 rue des Saints Pères, 75006, Paris (France); Gilleron, Jérome; Pointis, Georges [INSERM U 1065, Team 5 “Physiopathology of Germ Cell Control: Genomic and Non Genomic Mechanisms” C3M, University of Nice Sophia Antipolis, Nice (France); Segretain, Dominique [University of Versailles/St Quentin-en-Yvelines (France); UMR S775, University Paris Descartes, 45 rue des Saints Pères, 75006, Paris (France); Durand, Philippe [Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Université Lyon I, CNRS, INRA, Ecole Normale Supérieure de Lyon, Lyon (France); Kallistem SAS Ecole Normale Supérieure de Lyon, Lyon (France)

2013-04-01

Exposure to toxic metals, specifically those belonging to the nonessential group leads to human health defects and among them reprotoxic effects. The mechanisms by which these metals produce their negative effects on spermatogenesis have not been fully elucidated. By using the Durand's validated seminiferous tubule culture model, which mimics the in vivo situation, we recently reported that concentrations of hexavalent chromium, reported in the literature to be closed to that found in the blood circulation of men, increase the number of germ cell cytogenetic abnormalities. Since this metal is also known to affect cellular junctions, we investigated, in the present study, its potential influence on the Sertoli cell barrier and on junctional proteins present at this level such as connexin 43, claudin-11 and N-cadherin. Cultured seminiferous tubules in bicameral chambers expressed the three junctional proteins and ZO-1 for at least 12 days. Exposure to low concentrations of chromium (10 μg/l) increased the trans-epithelial resistance without major changes of claudin-11 and N-cadherin expressions but strongly delocalized the gap junction protein connexin 43 from the membrane to the cytoplasm of Sertoli cells. The possibility that the hexavalent chromium-induced alteration of connexin 43 indirectly mediates the effect of the toxic metal on the blood–testis barrier dynamic is postulated. - Highlights: ► Influence of Cr(VI) on the Sertoli cell barrier and on junctional proteins ► Use of cultured seminiferous tubules in bicameral chambers ► Low concentrations of Cr(VI) (10 μg/l) altered the trans-epithelial resistance. ► Cr(VI) did not alter claudin-11 and N-cadherin. ► Cr(VI) delocalized connexin 43 from the membrane to the cytoplasm of Sertoli cells.

Leukotriene B4 induces EMT and vimentin expression in PANC-1 pancreatic cancer cells: Involvement of BLT2 via ERK2 activation.

Science.gov (United States)

Kim, You Ri; Park, Mi Kyung; Kang, Gyeong Jin; Kim, Hyun Ji; Kim, Eun Ji; Byun, Hyun Jung; Lee, Moo-Yeol; Lee, Chang Hoon

2016-12-01

Leukotriene B 4 (LTB 4 ) is a leukocyte chemoattractant and plays a major role controlling inflammatory responses including pancreatitis. LTB 4 is known to be correlated with cancer progression. LTB 4 induces keratin phosphorylation and reorganization by activating extracellular regulated kinase (ERK) in PANC-1 pancreatic cancer cell lines. However, the role of LTB 4 in epithelial mesenchymal transition (EMT) and vimentin expression in pancreatic cancer cells is unknown. We examined whether LTB 4 induces EMT and vimentin expression by Western blot, si-RNA, and RT-PCR. LTB 4 induced morphological change, decreased E-cadherin expression and increased N-cadherin and vimentin expression. LTB4 increased migration and invasion of PANC-1 cancer cells. LTB 4 dose-dependently upregulated expression of vimentin in PANC-1 cancer cells. LTB 4 -induced vimentin expression was suppressed by LY255283 (BLT2 antagonist). Comp A, a BLT2 agonist, further increased vimentin expression. Gene silencing of BLT2 suppressed LTB 4 -or Comp A-induced vimentin expression in PANC-1 cells. The MEK inhibitor, PD98059 suppressed Comp A-induced vimentin expression. Comp A or transfection of plasmid containing BLT2 cDNA (pC BLT2 ) activated ERK, and BLT2 gene silencing suppressed Comp A-induced ERK activation. ERK2 siRNA abrogated Comp A-induced vimentin expression and ERK2 overexpression enhanced vimentin expression. One of well-known cause of ras mutation, cigarette smoke extracts increased BLT2 expression in PANC-1 cancer cells. Taken together, these results suggest that BLT2 is involved in LTB 4 -induced vimentin expression through ERK2 in PANC-1 cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

Executive control of stimulus-driven and goal-directed attention in visual working memory.

Science.gov (United States)

Hu, Yanmei; Allen, Richard J; Baddeley, Alan D; Hitch, Graham J

2016-10-01

We examined the role of executive control in stimulus-driven and goal-directed attention in visual working memory using probed recall of a series of objects, a task that allows study of the dynamics of storage through analysis of serial position data. Experiment 1 examined whether executive control underlies goal-directed prioritization of certain items within the sequence. Instructing participants to prioritize either the first or final item resulted in improved recall for these items, and an increase in concurrent task difficulty reduced or abolished these gains, consistent with their dependence on executive control. Experiment 2 examined whether executive control is also involved in the disruption caused by a post-series visual distractor (suffix). A demanding concurrent task disrupted memory for all items except the most recent, whereas a suffix disrupted only the most recent items. There was no interaction when concurrent load and suffix were combined, suggesting that deploying selective attention to ignore the distractor did not draw upon executive resources. A final experiment replicated the independent interfering effects of suffix and concurrent load while ruling out possible artifacts. We discuss the results in terms of a domain-general episodic buffer in which information is retained in a transient, limited capacity privileged state, influenced by both stimulus-driven and goal-directed processes. The privileged state contains the most recent environmental input together with goal-relevant representations being actively maintained using executive resources.

A Direct Adaptive Control Approach in the Presence of Model Mismatch

Science.gov (United States)

Joshi, Suresh M.; Tao, Gang; Khong, Thuan

2009-01-01

This paper considers the problem of direct model reference adaptive control when the plant-model matching conditions are violated due to abnormal changes in the plant or incorrect knowledge of the plant's mathematical structure. The approach consists of direct adaptation of state feedback gains for state tracking, and simultaneous estimation of the plant-model mismatch. Because of the mismatch, the plant can no longer track the state of the original reference model, but may be able to track a new reference model that still provides satisfactory performance. The reference model is updated if the estimated plant-model mismatch exceeds a bound that is determined via robust stability and/or performance criteria. The resulting controller is a hybrid direct-indirect adaptive controller that offers asymptotic state tracking in the presence of plant-model mismatch as well as parameter deviations.

Shape-controlled synthesis of nanocarbons through direct conversion of carbon dioxide

Science.gov (United States)

Zhang, Haitao; Zhang, Xiong; Sun, Xianzhong; Ma, Yanwei

2013-01-01

Morphology control of carbon-based nanomaterials (nanocarbons) is critical to practical applications because their physical and chemical properties are highly shape-dependent. The discovery of novel shaped nanocarbons stimulates new development in carbon science and technology. Based on direct reaction of CO2 with Mg metal, we achieved controlled synthesis of several different types of nanocarbons including mesoporous graphene, carbon nanotubes, and hollow carbon nanoboxes. The last one, to our knowledge, has not been previously reported to this date. The method described here allows effective control of the shape and dimensions of nanocarbons through manipulation of reaction temperature. The formation mechanism of nanocarbons is proposed. As a proof of concept, the synthesized nanocarbons are used for electrodes in symmetrical supercapacitors, which exhibit high capacitance and good cycling stability. The reported protocols are instructive to production of nanocarbons with controlled shape and dimensions which are much desirable for many practical applications. PMID:24346481

Direct design of LPV feedback controllers: technical details and numerical examples

OpenAIRE

Novara, Carlo

2014-01-01

The paper contains technical details of recent results developed by the author, regarding the design of LPV controllers directly from experimental data. Two numerical examples are also presented, about control of the Duffing oscillator and control of a two-degree-of-freedom manipulator.

TNFα-mediated loss of β-catenin/E-cadherin association and subsequent increase in cell migration is partially restored by NKX3.1 expression in prostate cells.

Directory of Open Access Journals (Sweden)

Bilge Debelec-Butuner

Full Text Available Inflammation-induced carcinogenesis is associated with increased proliferation and migration/invasion of various types of tumor cells. In this study, altered β-catenin signaling upon TNFα exposure, and relation to loss of function of the tumor suppressor NKX3.1 was examined in prostate cancer cells. We used an in vitro prostate inflammation model to demonstrate altered sub-cellular localization of β-catenin following increased phosphorylation of Akt(S473 and GSK3β(S9. Consistently, we observed that subsequent increase in β-catenin transactivation enhanced c-myc, cyclin D1 and MMP2 expressions. Consequently, it was also observed that the β-catenin-E-cadherin association at the plasma membrane was disrupted during acute cytokine exposure. Additionally, it was demonstrated that disrupting cell-cell interactions led to increased migration of LNCaP cells in real-time migration assay. Nevertheless, ectopic expression of NKX3.1, which is degraded upon proinflammatory cytokine exposure in inflammation, was found to induce the degradation of β-catenin by inhibiting Akt(S473 phosphorylation, therefore, partially rescued the disrupted β-catenin-E-cadherin interaction as well as the cell migration in LNCaP cells upon cytokine exposure. As, the disrupted localization of β-catenin at the cell membrane as well as increased Akt(S308 priming phosphorylation was observed in human prostate tissues with prostatic inflammatory atrophy (PIA, high-grade prostatic intraepithelial neoplasia (H-PIN and carcinoma lesions correlated with loss of NKX3.1 expression. Thus, the data indicate that the β-catenin signaling; consequently sub-cellular localization is deregulated in inflammation, associates with prostatic atrophy and PIN pathology.

Connective tissue growth factor enhances the migration of gastric cancer through downregulation of E-cadherin via the NF-κB pathway.

Science.gov (United States)

Mao, Zhengfa; Ma, Xiaoyan; Rong, Yefei; Cui, Lei; Wang, Xuqing; Wu, Wenchuan; Zhang, Jianxin; Jin, Dayong

2011-01-01

Local invasion and distant metastasis are difficult problems for surgical intervention and treatment in gastric cancer. Connective tissue growth factor (CTGF/CCN2) was considered to have an important role in this process. In this study, we demonstrated that expression of CTGF was significantly upregulated in clinical tissue samples of gastric carcinoma (GC) samples. Forced expression of CTGF in AGS GC cells promoted their migration in culture and significantly increased tumor metastasis in nude mice, whereas RNA interference-mediated knockdown of CTGF in GC cells significantly inhibited cell migration in vitro. We disclose that CTGF downregulated the expression of E-cadherin through activation of the nuclear factor-κappa B (NF-κB) pathway. The effects of CTGF in GC cells were abolished by dominant negative IκappaB. Collectively, these data reported here demonstrate CTGF could modulate the NF-κappaB pathway and perhaps be a promising therapeutic target for gastric cancer invasion and metastasis. © 2010 Japanese Cancer Association.

Integrated direct/indirect adaptive robust motion trajectory tracking control of pneumatic cylinders

Science.gov (United States)

Meng, Deyuan; Tao, Guoliang; Zhu, Xiaocong

2013-09-01

This paper studies the precision motion trajectory tracking control of a pneumatic cylinder driven by a proportional-directional control valve. An integrated direct/indirect adaptive robust controller is proposed. The controller employs a physical model based indirect-type parameter estimation to obtain reliable estimates of unknown model parameters, and utilises a robust control method with dynamic compensation type fast adaptation to attenuate the effects of parameter estimation errors, unmodelled dynamics and disturbances. Due to the use of projection mapping, the robust control law and the parameter adaption algorithm can be designed separately. Since the system model uncertainties are unmatched, the recursive backstepping technology is adopted to design the robust control law. Extensive comparative experimental results are presented to illustrate the effectiveness of the proposed controller and its performance robustness to parameter variations and sudden disturbances.

Epithelial rotation is preceded by planar symmetry breaking of actomyosin and protects epithelial tissue from cell deformations.

Science.gov (United States)

Viktorinová, Ivana; Henry, Ian; Tomancak, Pavel

2017-11-01

Symmetry breaking is involved in many developmental processes that form bodies and organs. One of them is the epithelial rotation of developing tubular and acinar organs. However, how epithelial cells move, how they break symmetry to define their common direction, and what function rotational epithelial motions have remains elusive. Here, we identify a dynamic actomyosin network that breaks symmetry at the basal surface of the Drosophila follicle epithelium of acinar-like primitive organs, called egg chambers, and may represent a candidate force-generation mechanism that underlies the unidirectional motion of this epithelial tissue. We provide evidence that the atypical cadherin Fat2, a key planar cell polarity regulator in Drosophila oogenesis, directs and orchestrates transmission of the intracellular actomyosin asymmetry cue onto a tissue plane in order to break planar actomyosin symmetry, facilitate epithelial rotation in the opposite direction, and direct the elongation of follicle cells. In contrast, loss of this rotational motion results in anisotropic non-muscle Myosin II pulses that are disorganized in plane and causes cell deformations in the epithelial tissue of Drosophila eggs. Our work demonstrates that atypical cadherins play an important role in the control of symmetry breaking of cellular mechanics in order to facilitate tissue motion and model epithelial tissue. We propose that their functions may be evolutionarily conserved in tubular/acinar vertebrate organs.

Maintenance and induction of murine embryonic stem cell differentiation using E-cadherin-Fc substrata without colony formation